Presentation type:
ERE – Energy, Resources and the Environment

EGU23-11361 | Orals | ITS3.2/ERE2.8 | ERE Division Outstanding Early Career Scientist Award Lecture

The role of the subsurface in the energy transition – (some of) the (scientific) challenges 

Johannes Miocic

The transition towards carbon-free, renewable based energy systems is a central element to limit global warming and is one of the key societal challenges we are currently facing. The subsurface offers many different pieces for the energy transition jigsaw, from renewable energy from geothermal sources to large volumes of pore-space to permanently sequester carbon dioxide. The subsurface also provides several options for storing renewable energy over seasonal timescales, by storing renewable energy surplus converted into hydrogen and compressed air. As the subsurface can be utilized for many different energy related purposes, it becomes clear that it has to be a crucial part of the energy-transition.  However, most subsurface utilization technologies are not yet used on the scale that is needed for a successful energy transition. One reason for this lies in the incomplete understanding of (geological) processes that occur in the subsurface during, and after, the operation of these technologies. Predicting the performance and the potential of subsurface utilisation in the energy transition can also be hampered by limited data availability and the uncertainties associated with sparse datasets. Here, some of the key geoscience challenges that need to be solved for a timely energy transition are presented and some potential solutions are reviewed. The subsurface can, and must, play an important role in tomorrow’s green energy systems!

How to cite: Miocic, J.: The role of the subsurface in the energy transition – (some of) the (scientific) challenges, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11361, https://doi.org/10.5194/egusphere-egu23-11361, 2023.

ERE1 – Integrated studies

EGU23-592 | ECS | PICO | ERE1.1

Assessment of direct and indirect emissions from the wastewater treatment plant and sludge processing: A case study 

Praveen Kumar Vidyarthi, Pratham Arora, Nadège Blond, and Jean-Luc Ponche

Due to rapid urbanisation and population, a constant supply of clean and fresh water has come under stress. Raw water must be continuously treated and supplied to satisfy the day-to-day needs for potable water for household use. To find a solution to the issue, several governments worldwide have moved their focus to water and sanitation. Large sewage and effluent treatment facilities are continuously working to treat wastewater, which is the most crucial step in addressing the problem of fresh water. Sludge is the main by-product produced by these treatment plants, which creates a challenge when it comes to disposal. The sludge is processed in the treatment facilities before being disposed of, allowing for better waste management. In the treatment process of the wastewater, from the moment the wastewater enters the treatment facility until the sludge is disposed of, there are multiple points at which emissions are produced. These emissions need to be evaluated and dealt with, as they have the potential to significantly impact climate change and the depletion of the ozone layer. The authors have analysed the emissions using several methodologies, including IPCC inventories, life cycle assessment, and many more. The study's findings indicate that a significant quantity of greenhouse gas emissions (directly and indirectly) and air pollutants are emitted during the process of treating wastewater and disposal of sludge.

How to cite: Vidyarthi, P. K., Arora, P., Blond, N., and Ponche, J.-L.: Assessment of direct and indirect emissions from the wastewater treatment plant and sludge processing: A case study, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-592, https://doi.org/10.5194/egusphere-egu23-592, 2023.

EGU23-919 | ECS | PICO | ERE1.1

Effect Of Channel Width on Energy Dissipation Efficiency of Stepped Spillway 

Ritusnata Mishra and Chandra Shekhar Prasad Ojha

Abstract:

Experimental investigation on flat stepped spillway were conducted with two different width 0.52m and 0.28m on 26.670 slope under nappe flow regimes. The study assessed the rate of energy dissipation at the toe of the spillway for unit discharge, q, ranging from 0.00954m2/s to 0.078854 m2/s for Froude number (Fr) between 0.5 to 0.85. The stepped chute comprised 10 identical steps having 0.10-m step heights and 0.2-m length. It is observed that the rate of energy dissipation at the step edge was relatively observed to be higher in the wider channel. The energy dissipation rate decreased from 3.81% to 26.135% by decreasing the channel width by 46.15% under same unit discharges. It signifies that the width of channel has certain influence on energy dissipation efficiency of spillway under same slope. Therefore, wider channel should be taken for design of stepped spillway under nappe flow regime. The variation in energy dissipation is due to the variation in mean air concentration between two widths. For further validation of these experimental observations, computational fluid dynamics (CFD) models were also used with k-ɛ turbulence model and0.010 m mesh size. 

Keywords: stepped spillway, energy dissipation, channel width, CFD

How to cite: Mishra, R. and Ojha, C. S. P.: Effect Of Channel Width on Energy Dissipation Efficiency of Stepped Spillway, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-919, https://doi.org/10.5194/egusphere-egu23-919, 2023.

For the formation of oil (PG), a certain geological and geochemical environment of the Earth's Crust is necessary. Geologically, the current PG models are based on a 2-layer model of the Earth's Crust, consisting of Granite and Basalt layers. However, as the drilling of the Kola Superdeep Borehole (SG3) showed, there is no basalt layer on the continents. A model of a 1-layer Earth's Crust was compiled, consisting of a granite layer on the continents and a basalt layer in the Oceans:[1 layer  Мodel of the Earth's Crust Galant (MECG), ( AAPG, Athens 2007; EGU, Vienna 2013,2022;)] сonsist of separated layers of  Granite  and separated layers of  Basalt. This Model of the Earth's Crust Galant (MECG) fundamentally changes the geological and geochemical setting of the Earth's Crust and hence the PG processes. Basalts and Granites are antipodes and therefore fluids migrating from the mantle with the goal of generating oil passing through the Earth's Crust that does not have Basalts but has only Granites will behave differently - respectively. In connection with the change in the geological and geochemical situation, the parameters of the fluid migrating from the mantle will also change: the C-O-H ratio, reactions with the components of the layer, the supply and removal of components, the change in T, the intensity of degassing, the change in the fugacity of O, the depth of the depleted mantle, etc. Since the Kola on the Baltic Shield did not reveal the basalt layer and due to this, the depth [According based on 1 layer Model of the Earth's Crust Galant (MECG), ( AAPG Athens 2007, EGU Vienna 2013)] of the granite layer reaches the mantle deeply and the greater the thickness the thickness of the depleted mantle is greater, from this it can be assumed that the mantle gave up light hydrocarbon components concentrated in the upper horizons of the Lithosphere, and heavy hydrocarbon components still remained in the depleted mantle or are now slowly migrating upward into the granite layer. This may explain that granites contain more light hydrocarbons. Due to the change in the physical and chemical conditions of the Earth's Crust, the PG depth zone changes, expands or localizes, and the composition of the oil changes accordingly. CONCLUSIONS: In connection with the 1-layer model of the Earth's Crust, the energy-material exchange between the domains of the Earth, the Mantle and the Lithosphere changes. Characteristics of the parameters of physic-chemical conditions change. And also the tactics, strategy, philosophy of PG research should change, taking into account the new model of the Earth's Crust.

 

How to cite: Galant, Y.: The Genesis of Oil in connection with a 1-layer Model of the Earth’s Crust, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1002, https://doi.org/10.5194/egusphere-egu23-1002, 2023.

Nano Fe(III) oxide (FO) was employed as an additive material for CO2-aided pyrolysis of spent coffee grounds (SCG) and its impacts on the syngas (H2 & CO) generation and biochar adsorption characteristics were examined. Amendment of FO led to 153 and 682% increase of H2 and CO in pyrolytic process of SCG, respectively, which is deemed to arise from enhanced thermal cracking of hydrocarbons and oxygen transfer reaction mediated by FO. Incorporation of FO successfully created porous structure in the produced biochar. The adsorption tests revealed that the biochar exhibited bi-functional capability to remove both positively charged Cd(II) and Ni(II), and negatively charged Sb(V). The adsorption of Cd(II) and Ni(II) was hardly deteriorated in the multiple adsorption cycles, and the adsorption of Sb(V) was further enhanced through formation of surface ternary complexes. The overall results demonstrated nano Fe(III) oxide is a promising amendment material in CO2-aided pyrolysis of lignocellulosic biomass for enhancing syngas generation and producing functional biochar.

How to cite: Cho, D.-W., Jang, J.-Y., Cheong, Y., and Yim, G.-J.: Co-thermochemical conversion of coffee grounds and nano Fe(III) oxides to fabricate metal-biochar for the simultaneous removal of Sb(V), Cd(II), and Ni(II) from  water, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1700, https://doi.org/10.5194/egusphere-egu23-1700, 2023.

EGU23-2222 | PICO | ERE1.1

Fabrication of PAC sludge-valorized biochars and their practical application to the remediation of methyl arsenic in wetlands 

Jungho Ryu, Young-Soo Han, Dong-Wan Cho, So-Jeong Kim, Yong-Chan Cho, Chul-Min Chon, Joo Sung Ahn, and In-Hyun Nam

This study aims to mitigate As pollution in wetlands by using biochar composites, which are a byproduct of valorizing drinking water treatment sludge (i.e., polyaluminum chloride (PAC) sludge). PAC sludge produced when PAC is used as a coagulant contains various aluminum and iron components because of the high affinity of PAC for heavy metals. Therefore, the valorization of PAC sludge by pyrolysis can be a strategic method to secure environmental safety for sludge utilization by destroying the organic pollutants and immobilizing heavy metals while simultaneously producing biochar composites that can be used as an environmental adsorbent. Biochar composites were fabricated under N2 and CO2 environments, systematically characterized by X-ray diffraction, thermogravimetric, and Brunauer–Emmett–Teller/Barrett–Joyner–Halenda analyses, and tested for the adsorption of As species. Both biochar composites exhibited excellent adsorption performance for both inorganic As (As(III) and As(V)) and organic As (dimethylarsinic acid, DMA). A lab-scale microcosm test showed that ~30% of spiked DMA was removed by biochar and that the total As fixed in the sediment decreased by ~20%. In addition, the As speciation results for the sediment and biochar revealed demethylation of the DMA and reduction of As(V) to As(III) by microorganisms, which was confirmed by a microbial growth batch test. Finally, a large-scale field experiment carried out in an artificial ecological wetland ensured that the addition of biochar could reduce the total amount of As to be immobilized in wetland sediment by 19%. In addition, the presence of biochar could alter the migration trend of As species in plants by reducing the amount of organic As to be fixed in the sediment. The aforementioned results demonstrate the practical feasibility of using PAC sludge-derived biochar as an adsorbent for As species.

How to cite: Ryu, J., Han, Y.-S., Cho, D.-W., Kim, S.-J., Cho, Y.-C., Chon, C.-M., Ahn, J. S., and Nam, I.-H.: Fabrication of PAC sludge-valorized biochars and their practical application to the remediation of methyl arsenic in wetlands, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2222, https://doi.org/10.5194/egusphere-egu23-2222, 2023.

EGU23-2351 | PICO | ERE1.1

Water-energy-carbon nexus in Illinois - water supply risk for carbon capture 

Zhenxing Zhang, Elias Getahun, Laura Keefer, Guanping Qie, and Andres Felipe Prada Sepulveda

Recently, University of Illinois has been working on the front-end engineering design (FEED) of carbon capture facilities for several power plants in Illinois. While carbon capture facilities often would need cooling water for operation, the water demand for power plants carbon capture facilities has not received much attention. For the two real-world FEED design projects (the Prairie State Generating Company (PSGC) and the 21st Century Power plant (21CPP)), we comprehensively analyze the water demand and supply risks for the two carbon capture facilities. Both power plants and the associated carbon capture facilities are expected to run for decades and thus climate change would play key role in managing water supply risks which is important for informing the engineering design of water system and cooling system of the carbon capture facilities. Both historic and future hydrologic conditions are examined to determine water supply risks. Future hydrologic conditions are simulated using hydrologic models and global circulation models (GCM) results. The climate scenarios are adopted from the Coupled Model Intercomparison Projection Phase 5 (CMIP5) datasets. Three representative concentration pathways (RCPs), i.e. RCP2.6, RCP4.5, and RCP8.5, are employed for exploring different future carbon dioxide emission scenarios. This work explores the tradeoff between water footprint and carbon footprint of power plants in Illinois and provides scientific information for water management and carbon management and for engineering design of the real-world carbon capture facilities.

How to cite: Zhang, Z., Getahun, E., Keefer, L., Qie, G., and Felipe Prada Sepulveda, A.: Water-energy-carbon nexus in Illinois - water supply risk for carbon capture, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2351, https://doi.org/10.5194/egusphere-egu23-2351, 2023.

Prussian blue analogue (PBA) has been received great attention as a material for radioactive Cs removal because of its high Cs ion adsorption efficiency. In this study, we synthesized PBA with three different transition metal ions (Ni(II), Co(II), and Fe(II) for NiFe-PBA, CoFe-PBA, and FeFe-PBA, respectively) and adjusted their particle sizes and surface areas by controlling the amount of stabilizing agent. They also composited with TiO2 and then compared the efficiencies of Cs ion adsorption under dark or UV light. The larger the surface areas and the smaller the particle size, the better the Cs ion adsorption, and the NiFe, NiFe-TiO2 and FeFe-TiO2 showed additional Cs ion adsorption under UV light irradiation. In particular, NiFe has an adsorption capacity of about 0.8 mmolg-1 and 1.7 mmolg-1 under dark and UV light, respectively, which is a result of about twice the increase in the adsorption capacity by UV light irradiation. In addition, the NiFe-TiO2 nanocomposite shows adsorption capacities of about 0.45 mmolg-1 and 1.5 mmolg-1 under dark and UV light, respectively, which is a result of about three times the increase in the adsorption capacity by UV light irradiation. Photo-induced additional adsorption on NiFe showed even with radioactive 137Cs adsorption. This enhanced Cs ion adsorption of NiFe happens due to photoinduced charge transfer in NiFe molecular, which leads to additional adsorption of Cs ions. This is very meaningful result because it is first study of photo-induced additional removal of Cs on PBAs.

How to cite: Kim, S., Kim, M., and Eun, S.: Photo-induced enhancement of radioactive 137Cs removal by adsorption on Prussian blue analogues, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2500, https://doi.org/10.5194/egusphere-egu23-2500, 2023.

EGU23-3456 | ECS | PICO | ERE1.1

Mathematical modeling of dispersed phase behavior of water-in-oil emulsions in electrostatic crude oil desalters 

Ghazal Kooti, Bahram Dabir, Reza Taherdangkoo, and Christoph Butscher

The produced crude oil from reservoirs usually contains a considerable amount of water which is submitted to large shear rates through production process, and due to the existence of natural surface-active agents in crude oils, stable water-in-oil (W/O) emulsions are formed. Effectively purifying the emulsified crude oil through the electrostatic desalting process plays an important role in reducing its water and water-soluble salts contents, which otherwise exacerbate oil deterioration, equipment corrosion, and catalysts deactivation in subsequent units. The electrostatic desalting process has proved to be an efficient means of separation using electrodes subjected to a high voltage to enhance the coalescence of water droplets. In this study, a mathematical model was developed to simulate the W/O dispersed flow to study the evolution of droplet size distributions in crude oil desalters. The population balance approach was employed to describe the behavior of W/O emulsions in the continuous phase assuming that the process is controlled by two simultaneous physical phenomena; breakage and coalescence of droplets. Experimental results on the W/O system were utilized to validate the mathematical model and the employed numerical technique. The agreement between the developed model and experimental droplet volume size distributions was shown to be satisfactory, confirming the further applicability of the model. The present study can be helpful for optimizing crude oil desalting operating conditions, enhancing efficiency, and decreasing energy and chemical consumption.

How to cite: Kooti, G., Dabir, B., Taherdangkoo, R., and Butscher, C.: Mathematical modeling of dispersed phase behavior of water-in-oil emulsions in electrostatic crude oil desalters, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3456, https://doi.org/10.5194/egusphere-egu23-3456, 2023.

Detection of high pesticide concentrations in sediments and water often leads to prioritizing a site as being ‘at risk’. However, the risk does not depend on pesticide concentration alone, but on other site-specific characteristics also. We developed an indicator that identifies the ‘Level of Concern’ by integrating five such characteristics: (i) pesticide concentrations in surface and groundwater causing risks to ecological health (ii) impacts on human health, (iii) water scarcity, (iv) agricultural production, and (v) biodiversity richness. We applied this framework in an agricultural region of the Lower Ganges Basin in West Bengal, India. We measured concentrations of selected organochlorine pesticides (OCPs) in surface and groundwater within an 8 km2 area in 2019. Of 20 banned and restricted OCPs, 11 were detected as a cause of high risk to ecological health and 10 were detected at concentrations above the Accepted Carcinogenic Risk Limit (ACRL) for humans. In the pre-monsoon, the mean concentrations of ΣOCPs in groundwater and surface water were 126.9 ng/L and 104 ng/L,in the monsoon they were 144.7 ng/L and 138 ng/L, and in the post-monsoon 122.1 ng/L and 147 ng/L respectively. In groundwater, no significant seasonal difference was observed in most pesticides. In the surface water, 7 pesticides were significantly higher in the monsoon and post-monsoon, which may be attributed to increased runoff as well as post monsoon application of OCPs. In September 2022we again measured OCP concentrations in surface water and sediment. The mean concentration of 14 of the 20 measured OCPs were found to be significantly lower in the post-pandemic period compared to the pre-pandemic time. These lower pesticide concentrations may indicate a reduced use of OCPs in agricultural practices during the pandemic. This area was identified as being at the highest Level of Concern, even though the OCP concentrations alone conformed to general guidelines.

How to cite: Ray, S., Mohasin, P., and Chakraborty, P.: Developing an Indicator of Pesticide Pollution Risk: Integrating the site specific water scarcity, biodiversity and impacts on human Health, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7429, https://doi.org/10.5194/egusphere-egu23-7429, 2023.

In recent times, the research trend has shifted towards identifying sustainable energy resources. Bioenergy generation employing wastewater and micro-organisms might be a potential solution to achieve this goal. In microbial fuel cells (MFC), the energy stored in the chemical bonds of contaminants present in wastewater is utilized by the micro-organisms for their metabolism in redox conditions. Furthermore, in this process, free electrons are released into the system, which are captured by the electrodes resulting in the generation of electricity in the external circuit. Hence, the system provides wastewater treatment along with bioenergy generation. However, the system finds difficulty in degrading recalcitrant organic compounds, such as pharmaceuticals and other emerging contaminants, which is possible in constructed wetland (CW) systems. However, CWs require a large footprint area. Recently, combined CW and MFC systems are being used for this purpose due to their resilience and capacity to produce electricity and provide a high level of wastewater treatment. Combined CW-MFC has been found to be more useful than either system alone by complimenting their issues as the redox conditions required for the proper functioning of the MFC system are available in the CW system. Furthermore, the high diversity of micro-organisms present in MFC improves the treatment efficiency of the CW system. This study involves the application of a combined CW-MFC system for the treatment of wastewater and the production of bioelectricity using Lemna minor as macrophyte species. Graphite plates were used as the anode and cathode for electricity production. In order to test the system's effectiveness in terms of removing recalcitrant organic compounds, synthetic wastewater was spiked with 5 mg/L of sulfamethoxazole. The influence of various parameters, such as electrode spacing, the substrate to water depth ratio, and the initial COD concentration of wastewater, was studied. Considerably high removal of around 99% for sulfamethoxazole and 90% for COD removal were observed, along with the production of 133 mV of voltage. It was observed that with the increase in initial COD concentration and substrate to water depth ratio, COD removal also increased. However, an increase in electrode spacing and substrate to water depth ratio after a certain limit showed a negative effect on voltage generation. The entire system could effectively generate bioenergy and treat the sulfamethoxazole-contaminated wastewater.

Keywords- Constructed wetlands, Microbial fuel cell, Lemna minor, Emerging contaminants, Bioelectricity

How to cite: Jain, M., Ghosal, P. S., and Gupta, A. K.: Application of combined constructed wetland- microbial fuel cell system for simultaneous bioenergy generation and treatment of wastewater contaminated with sulfamethoxazole, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8535, https://doi.org/10.5194/egusphere-egu23-8535, 2023.

EGU23-10017 | ECS | PICO | ERE1.1

Inter-regional environmental imbalance under lasting pandemic exacerbated by residential response 

Chunjin Li, Jintai Lin, Lulu Chen, Qi Cui, Yu Liu, Erin E. McDuffie, Mingxi Du, Hao Kong, and Jingxu Wang

Pandemics greatly affect transportation, economic and household activities and their associated air pollutant emissions. In less affluent regions, household energy use is often the dominant pollution source and is sensitive to the affluence change caused by a persisting pandemic. Air quality studies on COVID-19 have shown declines in pollution levels over industrialized regions as an immediate response to pandemic-caused lockdown and weakened economy. Yet few have considered the response of residential emissions to altered household affluence and energy choice supplemented by social distancing. Here we quantify the potential effects of long-term pandemics on ambient fine particulate matter pollution (PM2.5) and resulting premature mortality worldwide, by comprehensively considering the changes in transportation, economic production and household energy use. We find that a persisting COVID-like pandemic would reduce the global gross domestic product by 11.2% and PM2.5-related mortality by 9.5%. The global mortality decline would reach 13.0% had the response of residential emissions been excluded. Among the 13 aggregated regions worldwide, the least affluent regions exhibit the greatest fractional economic losses with no comparable magnitudes of mortality reduction. This is because their weakened affluence would cause switch to more polluting household energy types on top of longer stay-at-home time, largely offsetting the effect of reduced transportation and economic production. International financial, technological and vaccine aids could reduce such environmental imbalance.

How to cite: Li, C., Lin, J., Chen, L., Cui, Q., Liu, Y., McDuffie, E. E., Du, M., Kong, H., and Wang, J.: Inter-regional environmental imbalance under lasting pandemic exacerbated by residential response, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10017, https://doi.org/10.5194/egusphere-egu23-10017, 2023.

EGU23-10512 | ECS | PICO | ERE1.1

Characterization of the social elements involved in socio-environmental conflicts in Mexico. 

Mario Alberto González Lezama, Nelly Ramírez Serrato, Mariana Patricia Jácome Paz, Isaac Hernandez Cedeño, and Luis Gabriel Duquino Rojas

 Socio-environmental conflicts are the result of an alteration in the natural environment that has repercussions on the interests of the social actors involved. The management of any case depends on the stage of the conflict, the interest in taking advantage of the resource, and the group that takes precedence over the change that this would imply. The environmental factors consist of many climatic, social, and economic variables that result in many types of conflict. For this, so many efforts have already been made to map these incidents at the national and international levels. One such mapping was conducted in the environmental justice atlas, an international compendium of environmental issues. However, little is known about the actors involved in such conflicts. The objective of this work is to identify the resistance actors reported by the Environmental Justice Atlas for Mexico and to search for available information on each of them, as well as the estimated or reported location of their headquarters. The main result was a cartographic mapping of the locations of these actors. The Environmental Justice Atlas registers 151 socio-environmental conflicts in Mexico, in which 485 civil organizations are or were in some way expressing their disagreement or rejection of some projects or megaprojects, while the Mexican government has participated with 171 institutions of the three levels of government, and has been judged and partnered in several of these conflicts; 186 state-owned companies representing the private sector have been identified as the ones responsible for affecting the interests of the actors on the territory and resources of their respective states. From this exercise, it was determined that not all actors have public location information, and even if they do have data, it is difficult to locate them, which could suggest a preference for anonymity when opposing different management of the territory and its resources and the awareness of possible risk in doing so.         

How to cite: González Lezama, M. A., Ramírez Serrato, N., Jácome Paz, M. P., Hernandez Cedeño, I., and Duquino Rojas, L. G.: Characterization of the social elements involved in socio-environmental conflicts in Mexico., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10512, https://doi.org/10.5194/egusphere-egu23-10512, 2023.

EGU23-12708 | ECS | PICO | ERE1.1

Negative Emissions based on Photoelectrochemical Methods: Surface Investigation of Potential Catalysts 

Daniel Lörch, Holger Euchner, Aya Mohamed, Peter Bogdanoff, and Matthias May

Mitigating climate change is one of the greatest challenges humanity has to face in the next decades. For this purpose, negative emissions – the active removal of large amounts of carbon dioxide from the atmosphere (~10Gt/a) – are indispensable, meaning that highly efficient methods for carbon dioxide removal have to be developed.1

In our work we aim to design a photoelectrochemical system that uses solar energy to drive a catalytic process that converts carbon dioxide into long term stable storage products such as oxalate or carbon flakes. Here, we present first results of electrochemical and spectroscopic investigations on two promising catalytic processes for carbon dioxide conversion which are based on metallic cerium and a GaInSn–based liquid metal alloy. The determination of the conversion efficiency allows for an estimation of the area demand of a large-scale deployment of our artificial photosynthesis-based process to meet the carbon dioxide reduction goals.

Apart from developing catalytic processes that result in high solar to carbon efficiencies, our work aims to improve the knowledge on the solid/liquid interface between catalyst and electrolyte. This is done by applying a combination of well established electrochemical methods like Cyclic Voltammetry or Chronoamperometry and operando Spectroscopy based on Raman and Reflection Anisotropy Spectroscopy. This is expected to allow for monitoring and controlling changes at the catalytic surfaces, like the formation of potentially catalyst poisoning species such as cerium fluoride. Since surface processes play a crucial role in the carbon dioxide conversion, understanding and controlling them might pave the way for improvements on the conversion efficiency. This would further reduce the area requirements of our system, which in turn would ease the suspected land-use conflict potential caused by climate change mitigation measures.

How to cite: Lörch, D., Euchner, H., Mohamed, A., Bogdanoff, P., and May, M.: Negative Emissions based on Photoelectrochemical Methods: Surface Investigation of Potential Catalysts, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12708, https://doi.org/10.5194/egusphere-egu23-12708, 2023.

EGU23-104 | ECS | Orals | ERE1.4

Does the assumption of biogenic carbon neutrality affect decarbonization pathways? Lessons learned from a techno-economic analysis 

Hamed Kouchaki Penchah, Olivier Bahn, Kathleen Vaillancourt, Lucas Moreau, Evelyne Thiffault, and Annie Levasseur

Net-zero emission targets require transitioning to low carbon energy sources (including bioenergy) and large-scale carbon dioxide removal. Aside from direct air capture (DAC), bioenergy with carbon capture and storage (BECCS) and terrestrial carbon removal and sequestration are two available negative emission technologies (NETs) ready for large-scale deployment. Nationally determined contributions endorse bioenergy as an alternative carbon neutral energy source for fossil fuels. However, this carbon neutral assumption is disputed with several studies indicating that it may lead to accounting errors and biased decision-making.

Bottom-up techno-economic energy system models such as the TIMES framework are used to identify and analyze potential decarbonization pathways for countries or regions. However, these models do not include biogenic carbon flows. Biogenic carbon refers to the carbon contained in biomass. One could assume that biogenic carbon is neutral since the amount of carbon emitted into the atmosphere through biomass combustion and the amount of carbon sequestered by plants during their lifetimes are equal. This assumption may be acceptable when the biomass rotation length is short, as in annual crops, and the balance between emissions and uptakes is indeed neutral. The assumption, however, may not remain valid when the sequestration period is lengthy, as in the case of forest trees. This study combines an aspatial, stand- and landscape-level modeling framework (CBM-CFS3) with a bottom-up techno-economic energy system model (NATEM). We use the CBM-CFS3 output to model various forest management strategies that would result in different biomass availability for bioenergy as well as net forest carbon stocks and emissions. This allows us to determine whether and how this biomass will be used in the energy system over time. Besides, we model several forest-based bioenergy and BECCS technologies to allow the energy system to use the available biomass. This is the first time biogenic CO2 flows are being modeled in a thorough energy system model such as TIMES. We show how the assumption of carbon neutrality results in biased decision-making (using different sets of NETs and resources). We demonstrate that the decarbonization effort could be reduced by integrating forest sequestration into the energy system model. We explore how a high sequestration capacity forest management strategy may minimize the need for expensive NETs such as DAC. Moreover, this research highlights the need to adopt the most promising forest management strategy before investing in BECCS.

How to cite: Kouchaki Penchah, H., Bahn, O., Vaillancourt, K., Moreau, L., Thiffault, E., and Levasseur, A.: Does the assumption of biogenic carbon neutrality affect decarbonization pathways? Lessons learned from a techno-economic analysis, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-104, https://doi.org/10.5194/egusphere-egu23-104, 2023.

EGU23-235 | ECS | Posters on site | ERE1.4

Life Cycle Assessment of mitigation measures of greenhouse gas emissions from beef production in England 

Asma Jebari, Adie Collins, Taro Takahashi, Michael RF Lee, Paul Harris, Laura Cardenas, Fabiana Pereyra, and Graham McAuliffe

British and Northern Irish agri-food systems are faced with the challenge of reducing their supply-chain emissions of greenhouse gases (GHGs) such as nitrous oxide (N2O), carbon dioxide (CO2) and methane (CH4) in line with the UK’s ambition of achieving a cross-sector ‘net zero’ economy by 2050. Approximately 10% of the GHG emissions are generated by agriculture, and approximately 56% of these GHGs are generated by livestock in the form of CH4 from enteric fermentation (eructation primarily) and manure management (i.e., storage and subsequent application as an organic fertiliser). Numerous mitigation strategies, both extant and at prototype stage, are being proposed to reduce GHG emissions from ruminants, with many aimed at reducing enteric CH4 (e.g., methane inhibitors such as 3NOP and ‘wearables’ which break CH4 down into CO2 and water vapour during respiration). Before implementing such practices, it is critical to evaluate their net impact on primary production GHG emissions (i.e., farm-level losses). Thus, a cradle-to-farm gate scale modelling framework combining a process-based model, the RothC Model, with Life Cycle Assessment (LCA) was conducted to explore the benefits and trade-offs of a range of intervention strategies for grazing beef systems in UK.

Mitigation interventions were applied to a baseline ‘business as usual’ scenario using the UK Research Council’s (UKRI) National Capability, the North Wyke Farm Platform utilising high resolution data collected on the world’s most instrumented research fam. Mitigation effects on net GHG emissions were subsequently assessed through an LCA scenario analysis with a view to identifying the most feasible, cost-effective strategies. The interventions assessed included: (i) grazing management (e.g., decreasing inputs of synthetic fertilisers and optimising stocking densities); (ii) manure management practices (e.g., adopting anaerobic digestion technology); (iii) livestock feeding regimes (e.g., dietary modification such as inhibitory supplementation) and breeding practices (, for instance, identifying high-performing breeding animals which have been shown to generate fewer GHGs whilst increasing both throughput and financial provision). Although the results to be presented in this work are currently preliminary, some notable findings with implications for policymakers have been observed already; for example, including carbon uptake from soils in a cradle-to-farmgate analysis can reduce system-wide emissions by ~10% in certain circumstances including climate, soil type, and manure management.

How to cite: Jebari, A., Collins, A., Takahashi, T., Lee, M. R., Harris, P., Cardenas, L., Pereyra, F., and McAuliffe, G.: Life Cycle Assessment of mitigation measures of greenhouse gas emissions from beef production in England, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-235, https://doi.org/10.5194/egusphere-egu23-235, 2023.

EGU23-2264 | ECS | Orals | ERE1.4

Modelling soil organic carbon stocks and greenhouse gases in European forests with multi-model ensembles 

Elisa Bruni, Bertrand Guenet, Rose Abramoff, Stefano Manzoni, Swamini Khurana, and Boris Tupek

State-of-the-art soil models can be used to monitor and predict the evolution of soil organic carbon (SOC) stocks and greenhouse gas (GHG) fluxes at national, sub-national, and supernational levels. This can help predict the effect of disturbances on the soil and facilitate the development of sustainable management practices to prevent further soil degradation and GHG losses under climate change.

However, model simulations are still highly uncertain due to many factors. For instance, the lack of understanding of many soil processes, the way processes are represented in the models, and the parametrization, initialization, and forcing variables used to run them. One way to consider these uncertainties is to use multi-model ensembles, thus simulating the evolution of SOC stocks and GHG fluxes according to models with different structures and mechanistic assumptions.

In this work, we show a webtool that enables the simulation of SOC stocks and GHG gases in European forests under different climate and land-use change scenarios, using a multi-model ensemble. In the absence of on-site measurements, the webtool directly accesses online databases of pedo-climatic data that is required to run the models.

Models also need to be correctly parameterized and evaluated before their application. For that, we build a map of model parameters that can be used to force the models, and which is evaluated on the European LUCAS database. Uncertainties linked to the initialization method used are also discussed.

How to cite: Bruni, E., Guenet, B., Abramoff, R., Manzoni, S., Khurana, S., and Tupek, B.: Modelling soil organic carbon stocks and greenhouse gases in European forests with multi-model ensembles, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2264, https://doi.org/10.5194/egusphere-egu23-2264, 2023.

While Africa has contributed negligibly to global emissions, it stands out as the world's most vulnerable region, owing to the continent's current low levels of socioeconomic growth and, thus, a lack of resources to afford the goods and services required to recover from the worst of the changing climate effects. Temperature and rainfall projections in disaster-prone areas are therefore critical for planning climate change mitigation and boosting our adaptation capacity to respond effectively. This study makes a contribution in this direction by identifying vulnerable areas to warming and drought in Africa, with a particular focus on Morocco—whose conditional goal, which will be attained with international assistance, is rated as "almost sufficient" but is not yet in alignment with the Paris Agreement's goal—, taking into account diverse levels of political efforts to slow down and adapt to climate change, known as the Shared Socio-Economic Pathways (SSPs), using the outputs of the global climate model, HadGEM3-GC31-LL, provided by the Coupled Model Intercomparison Project (CMIP) Phase 6 [1]. Temperature and precipitation projections over Africa indicate significant geographical variability in the twenty-first century. The northern part of Africa (NAF), the Sahara (SAH), and South West Africa (SWAF) are expected to undergo increasing warming, followed by Central Africa (CAF), North East Africa (NEAF), and South-East Africa (SEAF). When compared to other regions, West Africa (WAF) and Central East Africa (CEAF) will have the lowest mean annual temperature values. The SAH, NEAF, and CEAF are projected to get more precipitation than the NAF, WAF, SWAF, and SEAF, which are expected to endure severe drought conditions. The emission scenario has a large influence on the quantity of rain that falls over Central Africa (CAF), which has increased precipitation under the strong forcing scenario. The amount of greenhouse gases emitted globally over the next few decades (i.e., emission scenario) and the level of uncertainty in Morocco's climate sensitivity to those emissions (i.e., climate model, time horizon) will determine the extent of climate change in the next few decades. We estimate that significant reductions in greenhouse gas emissions could limit Morocco's annual average temperature rise to 1.07 °C (resp. 1.72 °C) in the near- (resp. long-) term. However, if these emissions are not greatly decreased, yearly average temperatures may rise by 1.25 °C (resp. 6.25 °C) by the end of the century. Morocco's spatio-seasonal warming pattern is highest in the mountainous areas of the Rif and Atlas Mountains and lessens along the Atlantic and Mediterranean Seas. The findings also point to a significant gradual emergence of humid climate in the South, as well as a migration of aridity to the North, East, and West. 

[1] Bouramdane, A.-A. Assessment of CMIP6 Multi-Model Projections Worldwide: Which Regions Are Getting Warmer and Are Going through a Drought in Africa and Morocco? What Changes from CMIP5 to CMIP6? Sustainability 2023, 15, 690. https://doi.org/10.3390/su15010690

How to cite: Bouramdane, A.-A.: Determining Vulnerable Areas to Warming and Drought in Africa and Morocco Based on CMIP6 Projections: Towards the Implementation of Mitigation and Adaptation Measures, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2456, https://doi.org/10.5194/egusphere-egu23-2456, 2023.

EGU23-2672 | ECS | Orals | ERE1.4

The impacts of ground-mounted solar parks on soil health in the UK 

Lucy Treasure, Alona Armstrong, Stuart Sharp, Simon Smart, and Guy Parker

Soils are a key natural capital asset. Soil health, defined as the capacity of a soil to function as a living system, is a vital component of wider ecosystem processes and functioning, including the flow of multiple ecosystem services. Land use change is an important factor influencing declines in soil health globally. To meet demand for low carbon energy, ground-mounted solar parks (SPs) have expanded rapidly in recent decades, incurring significant land use change, with predictions that UK solar capacity could quadruple by 2050. There is potential for both positive and negative impacts of SPs on soil health - SPs present a relatively unique land use change, in that large areas of land remain physically undisturbed but are shaded by panels. This shading can alter microclimate metrics under panels, including air and soil temperature, soil moisture, photosynthetically active radiation and humidity, which may impact indicators of soil health. Further, the majority of SPs in the UK are developed on former agricultural land, often intensively managed. Arable land use is one of the most detrimental to overall soil health, whilst there is significant evidence supporting the benefits of taking agricultural land out of cultivation, including increased soil carbon, reduced erosion, compaction, and pollution. Considering the land use requirements and microclimatic variation within SPs, it is critical that their impacts on soil health are understood, yet research on solar park-soil impacts remains sparse.

We investigated the impact of location within SPs (under solar panels and in gap areas) and the influence of prior land use (arable and grassland) on physical, chemical, and biological indicators of soil health, to address this knowledge gap and provide one of the first quantifications on the impacts of SP development on soil health.  Preliminary results suggest no difference in indicators with SP prior land use, however bulk density and inorganic phosphorus were significantly lower in gap areas compared to under panels, whilst organic matter and microbial biomass carbon were higher in gap areas. These results suggest that soil health may be degraded under the shade of solar panels.

However, on-site management decisions such as livestock grazing, wildflower planting and mowing regimes likely influence soil health indicator values and vary across SPs. Further, the SPs studied have been operational since 2014, a relatively short time in terms of soil health. As such, further research is required across spatial and temporal scales, considering the impact of SP management actions to accurately infer SP impacts on soil health.

How to cite: Treasure, L., Armstrong, A., Sharp, S., Smart, S., and Parker, G.: The impacts of ground-mounted solar parks on soil health in the UK, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2672, https://doi.org/10.5194/egusphere-egu23-2672, 2023.

EGU23-3063 | Posters virtual | ERE1.4

Protecting global forest to avoid carbon emissions 

Zhangcai Qin

The Glasgow Declaration on forests signed at the recent UN Climate Change Conference (COP 26) committed to halt forest loss by 2030. Over 141 countries and regions, collectively covering over 90% of global forest, endorsed this declaration, making it by far one of the largest forest protection programs in the world. Avoiding forest loss can generally contribute to climate change mitigation, however, the impacts of the declaration on global CO2 emissions reduction is still unclear. Here we show that by stopping global forest area loss, a large portion of deforestation-related CO2 emissions could be reduced, and the socio-economic damage to global society could be largely avoided. Over three quarters of emissions could be reduced over the next three decades, though any delays in implementing the declaration would decrease the avoided emissions. The value of the public goods provided by avoided deforestation could compensate for loss of private goods gained from clearing the land for agriculture. The Glasgow Declaration, if implemented fully and in a timely fashion, could help the world move closer to carbon neutrality.

How to cite: Qin, Z.: Protecting global forest to avoid carbon emissions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3063, https://doi.org/10.5194/egusphere-egu23-3063, 2023.

EGU23-4117 | Posters on site | ERE1.4

Decarbonization and sustainable energy transition to the post-lignite era in Greece 

Efthimios Tagaris, Apostolos Tranoulidis, Rafaella-Eleni P Sotiropoulou, and Kostas Bithas

It has been proved that reaching the objective of complete decarbonization in Greece by the year 2028 is necessary to ensure the stability of the country's power-generating system and Greece's energy security. Since the middle of the 1960s, when lignite reserves were exploited for the purpose of power production, the Region of Western Macedonia, which includes both an industrial and an agricultural sector, has held a unique position within the borders of Greece. However, as a result of a strategy for the transition to a more sustainable energy plan, the majority of plants that were powered by lignite were required to shut down in 2019. A just transition in a post-lignite era requires strategic planning in order to avoid social, economic, and energy issues while simultaneously maximizing the amount of power output that is sustainable. The present study makes use of a SWOT analysis in order to carry out a comprehensive socio-economic analysis for the Region of Western Macedonia. This analysis takes into account all of the primary economic sectors that are present in the region that is being studied, and it discusses the priorities that have been set by the Energy Union in order to achieve its energy goals. Additionally, the study discusses the results of a generalized SWOT analysis that was applied to the specific strategy of the Energy Union, placing special emphasis on the axes requiring further support actions. According to the findings of the study, the Region of Western Macedonia possesses significant advantages and presents a multitude of fresh chances as it makes the transition to a new production model. On the other hand, its unemployment rates are quite high, and its competitiveness and innovation rates are quite poor. The difficulty to locate sufficient employment opportunities is the primary factor contributing to the desertification of the region. When taking into account the aims of the Energy Union, the Region of Western Macedonia follows the priorities of Europe in its transition to the new production model in a satisfactory manner; yet, there is a significant amount of potential for development.

How to cite: Tagaris, E., Tranoulidis, A., Sotiropoulou, R.-E. P., and Bithas, K.: Decarbonization and sustainable energy transition to the post-lignite era in Greece, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4117, https://doi.org/10.5194/egusphere-egu23-4117, 2023.

EGU23-4490 | Orals | ERE1.4

Comparing Life-Cycle Environmental Impacts of Natural Gas-Fired and Renewable Electricity Generation 

Michael Young, Gurcan Gulen, Atta Ur Rehmman, and David Chapman

The mission of the Comparing Electricity Options (CEO) research program at UT Austin is to understand and quantify trade-offs among society’s goals of providing reliable and affordable energy, mitigating climate change, and improving local environments that can sustain a healthy economy for future populations. Our goals are to create tools that support decision makers in the energy and policy sectors with better environmental and economic assessments to manage environmental, social, and governance risks across global supply chains; highlight where innovation can mitigate impacts; and, inform policies that encourage innovation. This is done by conducting a three-phase, data-driven study of natural gas-fired, wind, and solar power plants (including batteries to address intermittencies). We use several methodologies and will develop interactive tools to allow wider audiences to quickly compare alternative scenarios. In Phase 1, which we anticipate will be completed in early 2023, we conduct a life-cycle assessment (LCA) of power plants for 18 impacts covering greenhouse gas and local (PM, SOX, NOX) emissions; land and water use and pollution, biodiversity and ecosystem services, etc. The LCA system boundaries encompass extraction of natural resources, manufacturing of generation equipment, power plant operations, and end-of-life. In Phase 2, which will begin in mid-2023, we investigate electric power grids instead of individual power plants, and aggregate environmental impacts and costs associated with transitioning generation mixes over time, including new transmission and distribution infrastructure. In Phase 3, we use results from Phases 1 and 2 to develop a new cost estimate for electricity at the consumer level that includes environmental and system costs. We show early results from Phase 1 and how environmental impacts are manifested along the global supply chains needed to support energy development, at different times during the 30-year lifespan of the facilities.

How to cite: Young, M., Gulen, G., Ur Rehmman, A., and Chapman, D.: Comparing Life-Cycle Environmental Impacts of Natural Gas-Fired and Renewable Electricity Generation, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4490, https://doi.org/10.5194/egusphere-egu23-4490, 2023.

EGU23-4912 | ECS | Orals | ERE1.4

Appropriate solar park management enhances bumble bee populations under different land use scenarios 

Hollie Blaydes, Emma Gardner, Duncan Whyatt, Robert Dunford, Simon Potts, and Alona Armstrong

Land use change for solar parks could provide a unique opportunity to support insect pollinators, such as bumble bees, if located and managed appropriately. Vegetation management can provide floral and nesting resources for bumble bees and well managed solar parks could safeguard suitable bumble bee habitats for up to 40 years. Understanding the potential for solar parks to contribute to bumble bee conservation is growing, but the longer-term roles of solar parks have not yet been considered. To address this knowledge gap, we used a geographic information system (GIS) and a process-based pollinator model to quantify the impact of solar park management on bumble bee density in present day Great Britain and in 2050. Future landscapes were based on state-of-the-art UK-SCAPE CRAFTY-UK scenarios that represent how land use responds simultaneously to climatic and social change. Scenarios range in levels of sustainability and therefore deliver contrasting landscapes that impact bumble bees in both solar parks and the surroundings. In the present day, solar parks managed with resource-rich wildflower margins approximately doubled bumble bee density compared to those managed as turf grass. Moreover, bumble bee density was higher in solar parks surrounded by more floral resources. In future scenarios, the impact of solar park management differed depending on how the surrounding landscape changed. Our findings suggest that solar parks could contribute to bumble bee conservation both now and in the future, potentially becoming more or less valuable habitats depending on land use change.

How to cite: Blaydes, H., Gardner, E., Whyatt, D., Dunford, R., Potts, S., and Armstrong, A.: Appropriate solar park management enhances bumble bee populations under different land use scenarios, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4912, https://doi.org/10.5194/egusphere-egu23-4912, 2023.

EGU23-5329 | ECS | Posters on site | ERE1.4 | Highlight

Change in soil organic carbon content in European mountain forests based on LUCAS soil databases 2009-2018 

Magdalena Gus-Stolarczyk, Anna Bartos, Agata Gołąb, and Łukasz Musielok

Forest ecosystems act as huge reservoirs of organic carbon by binding atmospheric carbon dioxide in the process of photosynthesis. Carbon in forests is stored both in aboveground and belowground biomass as well as in the form of dead organic matter in the soil. This soil organic carbon (SOC) pool may play a particularly important role in mitigating climate change through the long-lasting retention of organic compounds.

Much of Europe's forests are located in the mountains, where low temperatures and high humidity protect dead organic matter from rapid oxidation. In addition, the area covered by forests is increasing due to forest succession in abandoned areas. Both land cover change, as well as tree species conversion, are the factors that can lead to significant changes in SOC content. Thus, the aim of this study was to determine the impact of land use, land-use change, and forestry (LULUCF) on SOC content in European mountain forest ecosystems.

Data on land cover and SOC content in European mountains (areas above 500 m a.s.l.) were obtained from the 2009, 2015 and 2018 Land Use and Coverage Area frame Survey (LUCAS) databases. We compared the SOC content of sites that were under forests in 2009 or 2018, with or without changes in land use or species composition over the designated period. The highest increase in SOC content was noted at sites where conversion from meadow to deciduous forest took place (mean 3.46 g C kg-1 year-1). The SOC content decreased at sites that in the period 2009-2018 were constantly under mixed forests (mean -0.87 g C kg-1 year-1) and under coniferous forests (mean -0.21 g C kg-1 y-1), while at sites located under deciduous forests, the SOC content increased (mean 1.08 g C kg-1 y-1). These results suggest that forestation and maintenance of deciduous forests may have the greatest impact on carbon sequestration in mountain ecosystems in Europe.

This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 952327 (HES-GEO).

How to cite: Gus-Stolarczyk, M., Bartos, A., Gołąb, A., and Musielok, Ł.: Change in soil organic carbon content in European mountain forests based on LUCAS soil databases 2009-2018, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5329, https://doi.org/10.5194/egusphere-egu23-5329, 2023.

EGU23-5703 | ECS | Orals | ERE1.4

Long-term impact of land-use change on soil organic carbon in German agriculture 

David Emde, Axel Don, Christopher Poeplau, and Florian Schneider

Land-use change and land management practices alter soil organic carbon (SOC) dynamics in agricultural systems. Changing natural vegetation to agriculture in particular has resulted in a loss of approximately 5% of the current global terrestrial carbon stock. However, this carbon loss is reversible. Increasing the area of grassland is, therefore, an increasingly discussed climate change mitigation option since grasslands often store similar SOC stocks to natural vegetation. However, the time it takes for cropland to return to its pre-cropland carbon state after conversion to grassland is far from certain. Using soil and land-use history data gathered during the German Soil Inventory as well as from historical land use maps, this study therein aims to answer two questions: i) how does land-use change affect SOC stocks in agricultural systems; and ii) how long does it take for agricultural lands to reach a new SOC equilibrium following land-use change. By substituting space for time and accounting for differences in site properties via stratification, our results challenge the established “slow in, fast out” paradigm. At a national scale, topsoil SOC is lost relatively slowly when grassland is converted to cropland, and gained relatively quickly when cropland is returned to grassland. Further, neither direction of SOC change agreed with the 20 years’ timescales on which current emission reporting and climate mitigation policy is based, and SOC stocks were influenced by land-use changes for more than 100 years.

How to cite: Emde, D., Don, A., Poeplau, C., and Schneider, F.: Long-term impact of land-use change on soil organic carbon in German agriculture, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5703, https://doi.org/10.5194/egusphere-egu23-5703, 2023.

EGU23-5983 | ECS | Orals | ERE1.4 | Highlight

A multi-objective approach to design integrated multi-energy systems for efficient and sustainable decarbonization at the regional level 

Marco Tangi, Simona Ruggeri, Matteo Troncia, and Alessandro Amaranto

The decarbonization of the energy sector is among the highest priorities in the European Union’s effort to reduce its greenhouse gas (GHGs) emissions, avoid the worst effects of rapid climate change, and transition to a more sustainable economy. Multi-energy systems (MESs) have emerged as powerful and flexible solutions to integrate renewable energy sources (RES) in the energy grid and support the decarbonization of heating and transport. In MESs, multiple energy vectors and sectors that are traditionally planned and operated independently like electricity, heating and cooling, fuel and transport are coupled with each other at various levels, from demand to storage and generation, with the aim of increasing the efficiency, resilience, and sustainability of the whole system.  
The transition to carbon-neutral energy systems may come with significant costs, especially in areas where the social and economic opportunities are tied to carbon-intensive activities or where the land-use change to accommodate RES carries significant environmental and social impacts. In these contexts, where multiple stakeholders with competing objectives are involved, multi-objectives modeling tools can be used to support decision-makers in identifying the most suitable technical configuration of MESs to fulfill the decarbonization and economic goals while considering the needs of the territory involved and the assets and resources already available. 
This work presents a novel approach to identifying optimal solutions when designing MES under multiple competing environmental, economic, technological, and social objectives. We use the multi-scale energy systems modeling framework CALLIOPE to simulate the optimal management of a MES with high temporal resolution under a specific system configuration. These configurations are explored via a Multi-objective Evolutionary Algorithm, to extract Pareto-optimal MES designs and highlight synergies and trade-offs between multiple objectives. 
The new framework is applied to the Sulcis Iglesiente (SI) Province in Sardinia, Italy; a territory that already faces severe socio-economic challenges which are at risk of being exacerbated by the planned phase-out of the local coal power plant. Together with the economic end emission targets, the analysis includes objectives such as land-use allocation for renewables, air quality, and local job opportunities and losses. 
The resulting MES configurations, as expected, highlight a strong conflict between the maintenance of the previously carbon-intensive assets and the reduction of GHGs emissions. From the demand side, substituting fossil fuel boilers with heat pumps to exploit the excess electricity production that follows the expansion of the already existing renewable resources pool (mainly via new on-shore wind turbines) represents a good solution to increase efficiency and reduce the overall carbon footprint. However, from the generation side, fully compensating for removing the fossil fuel-based power plant would require massive investment in on-the-ground photovoltaic, and wind turbines (off-shore and on-shore), which may be too costly in terms of investment, surface allocation and landscape degradation. 

How to cite: Tangi, M., Ruggeri, S., Troncia, M., and Amaranto, A.: A multi-objective approach to design integrated multi-energy systems for efficient and sustainable decarbonization at the regional level, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5983, https://doi.org/10.5194/egusphere-egu23-5983, 2023.

EGU23-7116 | ECS | Orals | ERE1.4

Reconciling differences in CO2 emissions and removals from LULUCF by separating natural and land-use CO2 fluxes at the country level 

Clemens Schwingshackl, Wolfgang A. Obermeier, Selma Bultan, Giacomo Grassi, Josep G. Canadell, Pierre Friedlingstein, Thomas Gasser, Richard A. Houghton, Werner A. Kurz, Stephen Sitch, and Julia Pongratz

Anthropogenic and natural CO2 fluxes on land constitute substantial CO2 emissions and removals but are usually not well distinguished in national greenhouse gas inventories (NGHGIs) submitted to the United Nations Framework Convention on Climate Change (UNFCCC). Instead, countries frequently include natural and indirect human-induced CO2 fluxes on managed land in their estimates of CO2 fluxes from land use, land-use change, and forestry (LULUCF), mostly due to methodological constraints. Comparisons of anthropogenic LULUCF flux estimates from global models and from NGHGI reports thus reveal a substantial gap. Globally, this gap could be successfully reconciled by considering the different definitions used by global models and by NGHGI reports. Recent improvements in LULUCF flux modelling enable such a reconciliation now also at the country-level.

We separate natural and land-use-related CO2 fluxes from NGHGI reports in eight countries using global models to assess and improve the attribution of land CO2 fluxes to direct anthropogenic activities. In most investigated countries, the gap between model-based and report-based CO2 flux estimates is reduced (by up to 70%) if natural and indirect human-induced CO2 fluxes on managed land are considered. This confirms that the methodological discrepancies between NGHGI reports and global model estimates of LULUCF emissions are primarily due to differing estimation and reporting definitions, which need to be considered when accounting for country contributions to global climate mitigation targets. Further examinations show that remaining differences are linked to country-specific discrepancies between model-based and report-based estimates, such as incomplete reporting by countries, uncertainties in historical land-use dynamics, and model limitations. Moreover, most countries report the areas considered as managed without explicit information on their location, which prevents a precise spatial identification necessary for a detailed comparison of natural fluxes in managed forests with model-based estimates.

Reconciling estimates of LULUCF fluxes in individual countries by separating natural and land-use-related CO2 fluxes at national scales provides an important step toward a transparent assessment of LULUCF fluxes from NGHGI reports and supports a fair burden sharing of climate mitigation across countries.

How to cite: Schwingshackl, C., Obermeier, W. A., Bultan, S., Grassi, G., Canadell, J. G., Friedlingstein, P., Gasser, T., Houghton, R. A., Kurz, W. A., Sitch, S., and Pongratz, J.: Reconciling differences in CO2 emissions and removals from LULUCF by separating natural and land-use CO2 fluxes at the country level, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7116, https://doi.org/10.5194/egusphere-egu23-7116, 2023.

EGU23-7344 | ECS | Orals | ERE1.4

Mercury Emissions under Different Climate Pathways 

Flora Maria Brocza, Robert Sander, and Peter Rafaj

Global anthropogenic mercury (Hg) emissions are a long-lived hazard to human and environmental health. Targeted efforts to ban anthropogenic uses and trade and other releases of mercury and its compounds are underway through the UN Minamata Convention on Mercury [1]. However, more than half of Hg emissions in 2015 were linked to unintentional release via the combustion of fossil fuels (especially coal) and industrial activities such as metals production. Thus, in addition to mercury-specific policies and interventions, global action on climate change and the accompanying transition in energy systems, as well as the demand for metals and cement are important drivers of future mercury emissions.

The Greenhouse Gas – Air Pollution Interactions and Synergies (GAINS) model is an integrated assessment model that explores cost-effective multi-pollutant emission control strategies which aim at maximizing impacts of improved local and global air quality and emissions abatement. Hg-GAINS, as developed by Rafaj et al. [2] is one of few models which currently represents all anthropogenic mercury emission sources on a sector-by-sector basis. A recent update enhances representation of the co-benefits for mercury emissions from particulate matter (PM) and SO2 controls and extended the representation of Hg-specific control technologies. Climate and energy policy is represented through exogenous inputs into the model.

We quantify the relative importance of climate policy, co-benefits from PM and SO2 controls and technological mercury pollution control measures by comparing six scenarios of global mercury emissions in 5-year steps from 2010 up to 2050. Three energy scenarios from IEA World Energy Outlook 2022 (A - “Stated Policies (STEPS)”,  B - “Advanced Pledges (AP)”,  C - “Net Zero Emissions (NZE)”  [3]) are combined with two strategies of mercury emission control (1 - Current Legislation (CLE) , assuming technical mercury control compliant with the Minamata convention and national emission standards, relying mainly on co-benefits from PM and SO2 control; 2 - Maximum Feasible Reduction (MFR), assuming utilisation of the most efficient Hg-specific technologies and measures across all sectors). The share of Hg emissions from fossil fuel combustion is decreasing significantly in the Net Zero scenario (NZE-CLE) by 2050. Additionally, stringent air pollution policy reduces Hg emissions from this sector globally in all energy CLE scenarios. However, material and metal demand, driven by the deployment of renewable energy, as well as population growth both lead to a net increase of Hg even in NZE-CLE, which can only be resolved by applying stringent MFR controls for mercury (NZE-MFR).


[1] UNEP (2019). Minamata Convention on Mercury. Text and Annexes. www.mercuryconvention.org.

[2] Rafaj, P., Bertok, I., Cofala, J., and Schöpp, W. (2013). Scenarios of global mercury emissions from anthropogenic sources. Atmospheric Environment, 79:472–479.

[3] International Energy Agency (2022). World Energy Outlook 2022.

How to cite: Brocza, F. M., Sander, R., and Rafaj, P.: Mercury Emissions under Different Climate Pathways, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7344, https://doi.org/10.5194/egusphere-egu23-7344, 2023.

EGU23-9861 | ECS | Orals | ERE1.4

Improving LULUCF carbon emissions/removals estimates for Flanders, Belgium, through high-resolution prediction of land use based on a machine learning approach 

Ellen Van De Vijver, Dries Luts, Joris Pieters, Kasper Cockx, Peter Willems, and Stijn Vanacker

The quality of national and regional estimates of carbon emissions/removals under the LULUCF sector directly depends on the quality of the used input data for land use and land use changes, and their associated carbon stocks and emission/removal factors. The increasingly strict European regulations for greenhouse gas (GHG) emission reporting and the growing importance of the LULUCF sector in climate action plans and policies provide clear incentives to strive for continuous improvement of LULUCF datasets, including their spatial and temporal resolution.

The region of Flanders, Belgium, is characterized by relatively heterogeneous land use, which is monitored at a high spatial resolution resulting in the triennial production of a detailed land use map (18 categories, raster map with cell size of 10 by 10 meters). However, the estimation of LULUCF carbon emissions/removals currently relies on a different, less detailed land use dataset (5 categories, regular grid of 6799 points each representing an area of approximately 2000 by 1000 meters). The use of the latter dataset is motivated by the adoption of a similar approach over the three regions of Belgium, to guarantee the consistent integration of regional carbon emissions/removals estimates into the national GHG inventory. Apart from the general limitations of a sample-based dataset, this LULUCF land use dataset provides insufficient detail to grasp the effect of LULUCF-related policies and measures, undermining the use of derived carbon emissions/removals estimates for policy evaluation and development at the level of Flanders.

To overcome the issues related with spatial (and temporal) resolution of the current LULUCF land use dataset, we tested a machine learning approach to integrate four more detailed data sources available for Flanders in order to predict the corresponding LULUCF land use at a resolution of 10 meters. More specifically, we used the land use file, the land use map, the land cover map, and the dataset of registered agricultural parcels as input data in a multinomial logistic regression, considering a search neighbourhood with a 10-m radius around an original LULUCF land use data point. The model was created based on input data for two years, namely 2012 and 2015. Of the original LULUCF dataset, 70% of the data points was used for training of the model, leaving 30% for validation. In a first test, a prediction accuracy of approximately 90% was achieved. After manual correction of the original LULUCF dataset, the accuracy improved to 94%.

Although the approach proved successful for the prediction of the LULUCF land use for the individual years considered, less satisfying results were found when using the predictions to derive the land use change between these years: a land use change was estimated to occur at 8% of the total area of Flanders, while this was only 2% and 4% based on the original dataset before and after manual correction. Considering the major significance of the land use change area in the estimation of carbon emissions/removals, further research is required to adjust the methodology in order to guarantee the prediction of a consistent land use time series.

How to cite: Van De Vijver, E., Luts, D., Pieters, J., Cockx, K., Willems, P., and Vanacker, S.: Improving LULUCF carbon emissions/removals estimates for Flanders, Belgium, through high-resolution prediction of land use based on a machine learning approach, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9861, https://doi.org/10.5194/egusphere-egu23-9861, 2023.

EGU23-10215 | ECS | Posters virtual | ERE1.4

Forest Restoration Potential in China: Implications for Carbon Capture 

Xin Jiang

When it comes to mitigating the damaging effects of deforestation and the adverse effects of rising carbon dioxide concentrations in the atmosphere, reforestation is an environmentally responsible and effective strategy. China, which has one of the most significant rates of afforestation in the world, has increased its forest cover from 16.6% when it was last measured twenty years ago to 23.0% when it is next measured in 2020. However, there is uncertainty regarding the maximum potential forest coverage that can be achieved through tree planting and restoration. We developed a random forest regression model to map the potential tree coverage across China. The model links environmental factors with the types of forests that are most appropriate. After removing already-forested areas, urban areas, and agricultural land covers and uses, we estimate that there is a total of 67.2 million hectares of land that is currently available for tree restoration. This is a 50% increase over the current understanding of the available land. The establishment of a forest on these lands would result in the creation of 3.99 gigatons of new carbon stocks both above and below ground, which would be an important contribution toward the goal of reaching carbon neutrality. This potential is geographically unbalanced, with the largest restorable carbon potential being located in the south-west (29.5%), followed by the north-east (17.2%), and then the north-west (16.8%). The results of our study highlight the importance of coordinating the planting of trees in reforestation efforts with the uneven distribution of potential carbon storage. Reforestation should provide other environmental services in addition to acting as a biological mitigation strategy to partially offset carbon dioxide emissions caused by the burning of fossil fuels. These services include the restoration of degraded soils, conservation of biological diversity, revitalization of hydrological integrity, localized cooling, and improvement in air quality. Instead of concentrating solely on the act of planting trees, we believe it is more beneficial for forest restoration efforts to concentrate on the ecosystem as a whole rather than just the trees themselves.

How to cite: Jiang, X.: Forest Restoration Potential in China: Implications for Carbon Capture, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10215, https://doi.org/10.5194/egusphere-egu23-10215, 2023.

Expansion of a development area can have a negative impact on ecosystems by decreasing or fragmenting habitats. As awareness of the importance of biodiversity and ecosystem services grows, ecosystem service evaluations are receiving increased attention. The geography surrounding the city of Incheon is ecologically valuable because its mudflats and coastal terrain make it ecologically diverse. It is a wildlife habitat and breeding site for endangered species as designated by the Ramsar Convention on Wetlands in 2014, and the subject of disputes between advocates of ecological protection and those favoring human development. This study used the InVEST model to analyze the changes in the ecosystem services in accordance with the agreement on the IFEZ. An analysis showed that the carbon fixation was reduced by 40% due to the development led by the agreement, leading to a decrease in carbon storage of 793,586.25 Mg of C. This study suggests that the value of ecosystem services and expansion of conservation areas should be considered as part of ecological research under economic free trade agreements. Lastly ecological changes associated with IFEZ designation should be examined, and maintenance and management of carbon storage to restore climate controls and the valu-ation of biodiversity should be considered by developers and government officials.  In the natural environment ecology the EIA for development, biodiversity, dominance, natural environment, cultural assets, and protected species are investigated. It is judged that it will be a meaningful study by applying the quantitative evaluation methodology of ecosystem services for the planned development area. Afterwards, it is judged that it can be used as basic data in making development pol-icy decisions through qualitative and quantitative evaluation along with other environ-mental fields by utilizing ICT and AI methods, which are related methodologies according to the 4th industrial revolution.

How to cite: Choi, J. and Lee, D. K.: Analysis of spatio-temporal carbon fixation change in Incheon, Korea, as a result of free trade Agreement, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10316, https://doi.org/10.5194/egusphere-egu23-10316, 2023.

EGU23-11668 | ECS | Posters on site | ERE1.4

The Hot Spot analysis of Land use and Land cover changes (LULCC) in South Korea and North Korea 

Whijin Kim and Woo-Kyun Lee

Land use and land cover changes (LULCC) as a part of ecosystems has a significant impact on carbon budget. According to IPCC, approximately 23% of carbon was emitted from the human activities in agriculture, forestry and other land use (AFOLU) from 2007 to 2016. However, land cover includes crucial sector for carbon stock, as well. The land cover consists of five categories which are used area, agricultural land, forest, grass, wet land, and barren. Among these categories, forest counts because of its capacity of carbon sequestration. It is essential to manage the land use and land cover changes effectively since it has lots of influences on carbon cycles. Also, the sustainable management of land use and land cover changes could contribute to reducing the carbon emissions such as preventing deforestation and revegetation. Therefore, this study aims at analyzing the frequent land use change region using hot spot analysis in South Korea and North Korea and estimating the carbon emission and removals from land cover changes. First of all, we tracked the land cover changes at 10 years interval from 1980s to 2010s and identified the general trends. The changed area and ratio of each land cover were varied in both countries, but they had similar characteristics which is land cover changes from forest to cropland and from cropland to forest. It occurred for last four decades. To define the which region has been changed, the hot spot analysis was utilized. The change from forest to cropland appeared in southwest region of North Korea, major agriculture land. On the other hand, the transition from agriculture land to forest seemed to be minor, but the distinguished figure was created during the 2000s to 2010s change. The carbon emission was estimated at the hot spot area and these repeated changes led to additional carbon emission. This study would contribute to preventing the land cover changes frequent by defining the region to be managed.

How to cite: Kim, W. and Lee, W.-K.: The Hot Spot analysis of Land use and Land cover changes (LULCC) in South Korea and North Korea, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11668, https://doi.org/10.5194/egusphere-egu23-11668, 2023.

EGU23-12710 | ECS | Orals | ERE1.4

Eddy covariance CO2 flux data for supporting local climate change mitigation policies. 

Luca Tuzzi, Marta Galvagno, Gianluca Filippa, Edoardo Cremonese, Alessio Collalti, Luca Franzoso, Enrico Tomelleri, Riccardo Scodellaro, Laura Sironi, and Roberto Colombo

Under the Paris Agreement, countries are encouraged to preserve and enhance existing carbon sinks, especially forests, thereby including the LULUCF (Land Use, Land Use Change and Forestry) sector in international climate mitigation targets. In particular, Europe has set the target to reach climate neutrality, i.e. a balance between anthropogenic emissions by sources and removals by sinks, by 2050. A prerequisite to reach these goals is an accurate and credible estimation of both these large fluxes. However, recent works highlighted the uncertainty related to the quantification of the land sector mitigation potential, one of the most challenging emission sectors. Moreover, the definition of climate mitigation policies often occur at the local level, where details on CO2 removals from forests and other land uses are traditionally lacking. Indeed, local authorities  (e.g. cities and Regions) can be more effective in the transition to a sustainable economy compared to higher level authorities such as Nations.

In this study, we tested a data-driven method based on eddy covariance (EC) data to quantify the current LULUCF role to the regional carbon sink of the Aosta Valley Region (Italy), by the integration of different approaches. Our model is based on eddy covariance measurements of CO2 fluxes, MODIS NDVI (250m), daily gridded meteorological variables at 100m spatial resolution, and a land cover map at 250m spatial resolution. A Random Forest model was used to up-scale the point eddy covariance data to the Regional level, by testing different sets of drivers (air temperature, VPD, Snow (presence/absence), NDVI, solar radiation,...). Our model was then compared to independent data derived from the National Forest Inventory (NFI), and a process-based model. Preliminary results show that forests and other ecosystems of the Region remove nearly 70% of the total anthropogenic emissions in this area. The discrepancies between the different methods will be discussed by exploring the different advantages and flaws and the spatio-temporal variability of the different approaches. Such an assessment of the local carbon budget and its uncertainties will provide a solid base for Climate-smart management of the territory and thus for reaching the carbon neutrality targets.

How to cite: Tuzzi, L., Galvagno, M., Filippa, G., Cremonese, E., Collalti, A., Franzoso, L., Tomelleri, E., Scodellaro, R., Sironi, L., and Colombo, R.: Eddy covariance CO2 flux data for supporting local climate change mitigation policies., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12710, https://doi.org/10.5194/egusphere-egu23-12710, 2023.

EGU23-13952 | ECS | Posters on site | ERE1.4

Comparison of the Life Cycle Analysis of inert electrodes and the Hall-Heroult process in aluminum production 

Bethany Bronkema, Gudrún Sævarsdóttir, and David C. Finger

Comparison of the Life Cycle Analysis of inert electrodes and the Hall-Heroult process in aluminum production

 

Bethany Bronkema bethanyb@ru.is Guðrún Arnbjörg Sævarsdóttir gudrunsa@ru.is

David C. Finger davidf@ru.is

 

To be presented orally at EGU2023 – April 23rd-28th.

  • Reykjavik University, School of Science and Engineering, Department of Engineering, Reykjavik, Iceland

 

The global production of pure aluminum consumes substantial amounts of energy and alone produces around 1.1 billion metric tonnes of carbon dioxide emissions (CO2, eq) each year, or around two percent of global emissions. The Hall-Heroult process is currently the only industrial process for primary aluminum production, producing up to two tonnes of CO2 per tonne of pure aluminum by electrolysis in a molten salt electrolyte using carbon anodes. However, the use of inert electrodes represents a low-carbon alternative to the Hall-Heroult process as direct emissions can be significantly reduced, lowering the CO2, eq footprint and the ecotoxicity of aluminum production. However, a transition to inert anodes implies a redesign of current electrolysis cells to optimize the energy requirement of the new process. In this study, we performed a life cycle analysis to compare the ecological footprint of the aluminum production process with inert electrodes and the Hall-Heroult process. The life cycle assessment was conducted using GaBi software linked to the ecoinvent database and complemented with primary data. We calculated the ecological footprint for five scenarios: i) using inert electrodes with a 13.5 kWh per kilogram of aluminum energy requirement, ii) using a 17 kWh per kilogram of aluminum energy requirement, iii) using Icelandic grid electricity (primarily renewable hydropower), iv) using a global energy mix (primarily based on fossil energy), and v) and “best case scenario” in which a renewable source of energy is assumed for the refinement stage preceding the smelting stage. Each of these scenarios were then compared with the ecological footprint for the Hall-Heroult process using carbon anodes. The preliminary results reveal that the energy mix always has the highest impact on the ecological footprint in the earlier refinement and electrolysis stages. However, using inert electrodes in smelters powered with renewable electricity can significantly lower the carbon footprint and ecotoxicity of aluminum production.

How to cite: Bronkema, B., Sævarsdóttir, G., and Finger, D. C.: Comparison of the Life Cycle Analysis of inert electrodes and the Hall-Heroult process in aluminum production, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13952, https://doi.org/10.5194/egusphere-egu23-13952, 2023.

EGU23-14564 | ECS | Orals | ERE1.4

Historical and future perspectives of agricultural land abandonment and carbon sequestration 

Stephen M. Bell, Alexander V. Prishchepov, Calogero Schillaci, Daniel Goll, and Philippe Ciais

For as long as agriculture has existed, agricultural land abandonment (ALA) has been a globally relevant land use change. Depending on the timescale considered and the definitions and methods used, spatial estimates of historical ALA range in the several hundreds of millions of hectares. ALA implies the spontaneous recovery of ecosystem properties towards pre-disturbance states. Because agricultural lands are often degraded and carbon depleted, the natural ability of abandoned agricultural lands to act as carbon sinks has been, and will continue to be, a significant component of the terrestrial carbon cycle. Here, we provide a brief snapshot of the history of ALA, its drivers, and its known ecosystem carbon impacts from ancient times to the present, especially since the mid-20th century. We then explore the current and future implications of ALA-derived carbon sequestration in Europe, focussing on soil organic carbon based on synthesized published data (chronosequences and paired plots) and land surface model estimates. The majority of abandoned agricultural lands serve as carbon sinks, but there are clear scenarios where carbon may be lost or unchanged even after several years post-agriculture. Our results show that management of abandoned agricultural lands must consider multiple factors such as past land use practices (e.g., croplands vs pastures, past crop types, etc.), future land use management practices (e.g., natural or assisted restoration), local climate variables, and the present soil quality and carbon stock to ensure steady carbon sequestration following agricultural cessation. To avoid lost opportunities for climate change mitigation, ALA requires dedicated research and policy attention because: 1) it is a widespread, ongoing global land use change; 2) it does not always result in carbon sequestration; 3) its carbon gains are often lost in the first few decades when agriculture is re-established; 4) and it can facilitate wildfires which can also reverse carbon gains.

How to cite: Bell, S. M., Prishchepov, A. V., Schillaci, C., Goll, D., and Ciais, P.: Historical and future perspectives of agricultural land abandonment and carbon sequestration, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14564, https://doi.org/10.5194/egusphere-egu23-14564, 2023.

EGU23-14986 | ECS | Orals | ERE1.4

The relationship  between spatial variation of greenhouse gases intensity and agri-environmental variables in Oil Palm plantations 

Lisma Safitri, Marcelo Galdos, Andy Challinor, and Alexis Comber

Oil palm (OP) plantations account for 1.7 % of global CO2 emissions. Numerous studies have focused primarily on greenhouse gas (GHG) emissions from peatlands, constituting 20% of total OP area in the two largest OP producing countries, Indonesia and Malaysia. Few studies have investigated the potential for reducing GHG emissions in OP plantations. Strategies to reduce emissions and sequester carbon must consider how different practices affect production and the environment. Understanding the spatial distribution of GHG intensity and how the environment affects GHG intensity is therefore key to sustainable oil palm production.

GHG intensity was used as a metric to map the potential for sustainable OP plantations. GHG intensity represents the GHG emissions / removals (ton C ha-1) per unit of oil palm yields (ton ha-1). The approach for analysing the change in GHG emissions/ removals, referred to as the IPCC tier 1 method, is based on changes in soil organic carbon due to C and N emissions in drained peatlands and the associated change in aboveground biomass due to land use change. Changes in GHG intensity were investigated spatially for a case study in an industrial OP plantation located in Riau Province, Indonesia, from 2015 to 2019. Linear regression was used to analyse the relationships between GHG intensity and agri-environmental variables including NDVI, NPP, GPP, evapotranspiration, soil moisture in the root zone, soil moisture in deeper layer, C and N emissions from organic soils, and soil organic carbon (SOC).

The results show that around 90% of the new oil palm plantations in 2019 were converted from timber plantation, swamp scrubland, and bare land in 2015. Consequently, biomass growth from land use change acted as a carbon sink in this period. However, drained organic soils contributed significantly to GHG emissions. The change in GHG intensity in OP plantation in this study varied spatially from emitting (0.19 to 4.10 Ton C eq Ton-1 yields) to removing the GHG (0.23 to 2.40 Ton C eq Ton-1 yields). Among the environmental variables, NDVI and soil moisture showed the strongest relationship with GHG emissions/ removals (R2 = 0.23,   p value = < 2.2e-16) and yields (R2 = 0.2   p value = < 2.2e-16) in OP plantations.

These initial findings are advantageous for spatially identifying potential OP plantations that remove or emit GHG. Understanding the relationship between GHG emissions/removals and yields to environment variables provides insight into monitoring and enhancing OP sustainability, both from production and environmental perspectives. Future work will examine non-linear approaches to better model this relationship. 

 

 

How to cite: Safitri, L., Galdos, M., Challinor, A., and Comber, A.: The relationship  between spatial variation of greenhouse gases intensity and agri-environmental variables in Oil Palm plantations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14986, https://doi.org/10.5194/egusphere-egu23-14986, 2023.

EGU23-15110 | ECS | Orals | ERE1.4

Maximizing Ecosystem Services through Grassland Restoration and Adaptive Management in Solar Parks 

Mirjam Blecha, Michael Obriejetan, and Rosemarie Stangl

Keywords: Renewable energy, photovoltaics (PV), ecological restoration, ecosystem services, management strategies

The drive for renewable energy has resulted in a heightened focus on expanding sustainable energy systems, with solar PV playing a crucial role in this transition. While large-scale solar parks are met with controversy due to potential land-use conflicts and negative effects on the environment, they also present an opportunity for multifunctional land use. To address these concerns, an integrated research project in Austria was launched to develop strategies for integrating solar parks ecologically and maximizing ecosystem services through grassland restoration and adaptive management. Additional data and analysis will be used to improve the ecological integrity and biodiversity of solar parks and explore opportunities for combined agricultural use. By focusing on expanding renewable energy systems, solar PV in particular, and developing strategies for integrating them ecologically, we can address the global climate crisis and species extinction while also creating systems that are beneficial for both the environment and society in the long term.

However, specific and local conditions of solar parks must be considered in implementation and management. A monitoring system was set up to continuously record data on vegetation, local climate, and soil conditions, including measurements of soil water content, solar radiation, vegetation height, and plant species. Preliminary results show distinct effects of panel areas on several environmental factors, with the greatest impact on radiation and air temperature, also impacting the species composition in the area beneath and between panels.

How to cite: Blecha, M., Obriejetan, M., and Stangl, R.: Maximizing Ecosystem Services through Grassland Restoration and Adaptive Management in Solar Parks, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15110, https://doi.org/10.5194/egusphere-egu23-15110, 2023.

EGU23-15480 | ECS | Posters on site | ERE1.4

Water limits to curb climate change through large scale afforestation in the tropics and impacts on water availability for food production 

Livia Ricciardi, Paolo D'Odorico, Nikolas Galli, Davide Danilo Chiarelli, and Maria Cristina Rulli

Tree restoration plays a key role in curbing climate change by storing carbon. However, the impacts these strategies have on water resources is still unclear. While more and more areas are afforested every year, the extent to which these trees can grab rainwater and displace it from other uses while inducing water scarcity should be further investigated. Here, we examine the hydrological limits to tree restoration in tropics and the impacts of these strategies on water availability locally and downstream. We consider tropical biomes as case study since water is the main limiting factor to plant growth there. First, we use the spatially distributed agro-hydrological model WATNEEDS to evaluate the tree water requirement in suitable and available areas for tree restoration at pixel scale. Available areas for tree restoration are shrub areas not yet occupied by agricultural purposes or urbanization. Then, we compute the hydrological balance for different land use scenarios starting from present conditions (i.e., current land use) to tree restoration with and without yield gap closure (i.e., expansion of irrigation on currently rainfed areas).

We find that more than one third of suitable and available areas for tree restoration are in zones at high water stress for the plant, where rain alone can meet just up to the 40% of plant water requirement. Here, tree restoration causes substantial increase in water scarcity conditions, especially in the Horn of Africa and in Oceania. When accounting for both tree restoration and agricultural yield gap closure, water scarcity on these areas is exacerbated. Here, more than half of suitable and available areas for tree restoration will experience water scarcity conditions for at least six months per year.

It appears clear how competition for water resources reduces the benefits of tree restoration practices as plant growth is overall constrained by the lack of water.

How to cite: Ricciardi, L., D'Odorico, P., Galli, N., Chiarelli, D. D., and Rulli, M. C.: Water limits to curb climate change through large scale afforestation in the tropics and impacts on water availability for food production, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15480, https://doi.org/10.5194/egusphere-egu23-15480, 2023.

EGU23-16644 | ECS | Orals | ERE1.4

Assessing the impact of electric four-wheelers on the environment 

Anmol Jain, Eeshan Bhaduri, and Arkopal Kishore Goswami

According to the United Nations Environment Programme (UNEP), the transportation sector contributes approximately one-quarter of all energy-related greenhouse gas emissions. The increasing use of personal vehicles (PVs), especially conventional fuel-based four-wheelers, is significantly worsening the air quality index (AQI). Furthermore, the COVID-19 pandemic, during which social distancing was promoted as a preventative measure, has increased the propensity of PV use. As such, efforts to decarbonise transport have to be emphasised, wherein the adoption of electric vehicles (EVs) could play a crucial role. It is worth mentioning that European Union has been the global frontrunner for EV adoption with about 20% of its new vehicle stock being electric, while India is bridging the gap fast with its respective EV share being nearly 11%.

However, EVs per se might not be able to bring about changes in the existing scenario, as a substantial share of the electricity demand is met (for example, more than half of India’s production) through non-renewable energy sources. In such a situation, higher adoption of EVs would lead to increased demand for electricity, resulting in more emissions from thermal power plants, thus offsetting the reductions in tailpipe emissions. As such, this study analyses the environmental benefits of electrifying the passenger 4-wheeler transport sector by - (1) optimising the share of renewable energy sources (RES) and (2) facilitating higher shared usage of electric vehicles. While the existing studies largely focus on ownership and usage aspects of personal-use EVs, very few estimates the impact of the transition of different passenger commercial EV fleets and their emission implications for various RES utilisation. The present research aims to empirically assess demand for car-based travel alternatives (personal car, ride-hailing/ sharing, and taxi) while illustrating plausible electrification scenarios, considering emissions at sources. Such emissions are estimated through life cycle assessment (LCA) of vehicle operations and at power generation sources, i.e., thermal power plants. The current study considers vehicle level LCA including majorly three stages- (1) manufacturing, (2) operation, and (3) decommissioning-recycling, whereas the LCA at power generation sources was carried out at four stages- (1) upstream, (2) fuel cycle, (3) powerplant function and (4) downstream. This approach aids in developing a comparable emission estimate for EVs vis-à-vis conventional vehicles. At the same time, it presents a true view of EV’s emission reduction potential incorporating the RES transition effect.  

Data regarding user behaviour and choice towards the aforementioned four-wheeler-based alternatives have been collected using questionnaire surveys in Kolkata, India, and a multinomial logit model is developed. Subsequently, the model is used to develop scenarios for estimating the likely effects of electrification on travel choices. Finally, the LCA method, including exergy analysis and battery degradation, is used to calculate the impact of such travel choices on energy use and decarbonisation. The study is expected to provide empirical evidence for the viability of EV deployment in India and the benefits of switching to EVs with an increased share of RES in power generation.

Keywords: Electric vehicle (EV); Vehicular emissions; Lifecycle assessment (LCA); Renewable energy sources (RES)

How to cite: Jain, A., Bhaduri, E., and Kishore Goswami, A.: Assessing the impact of electric four-wheelers on the environment, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16644, https://doi.org/10.5194/egusphere-egu23-16644, 2023.

EGU23-17078 | ECS | Orals | ERE1.4 | Highlight

Trade-off scenarios in energy transition: The impact of social preferences and ecosystem services 

Boris Salak, Marcel Hunziker, Adrienne Grêt Regamey, Reto Spielhofer, Ulrike Wissen Hayek, and Felix Kienast

The siting of large energy facilities is a major challenge in countries where environmental and landscape issues related to outdoor recreation, place attachment, or tourism are publicly discussed, as the choice of the "optimal" location always depends on perspective. To allow informed decisions by policy makers, landscape research should provide data on current and potential future land use, public perceptions of landscapes and energy infrastructure etc. Decision support tools can convey this information to end users and help them to mimic tradeoffs between landscape issues and renewable energy development. However, these trade-offs often focus on techno-economic aspects and ignore environmental and social aspects. In this presentation, an optimization technique (MARXAN) is applied to mimic siting of renewable energy in Switzerland. Each potential energy site has costs in terms of ecosystem services and social preferences. MARXAN optimizes the selection of these sites to produce a given energy output at the lowest cost. It is shown that when focusing on the (often) common techno-economic approach, ecological costs peak while social costs are moderate compared to ecologically and socially oriented siting strategies. When siting incorporates ecosystem service costs, both spatial stress (claimed square kilometers of landscape for renewable energy infrastructure development) and social impacts peak, and when social costs are incorporated, both spatial and ecosystem service impacts turn out to be quite moderate. The results highlight the implications of a potential paradigm shift by showing the impact of integrating ecological and social information to provide informed decision support.

How to cite: Salak, B., Hunziker, M., Grêt Regamey, A., Spielhofer, R., Wissen Hayek, U., and Kienast, F.: Trade-off scenarios in energy transition: The impact of social preferences and ecosystem services, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17078, https://doi.org/10.5194/egusphere-egu23-17078, 2023.

EGU23-17242 | ECS | Orals | ERE1.4

Mapping peat layer thickness using machine learning and aerial laser scanning data 

Janis Ivanovs and Andis Lazdiņš

The surface of the earth's surface together with the granulometric composition of the soil are among the main parameters that determine the flow and accumulation of surface and underground water. Poorly drained and wet soils are important for biodiversity, water exchange, various chemical and biological processes, as well as for organic carbon accumulation. This research was done within the framework of the project Demonstration of climate change mitigation potential of nutrients rich organic soils in Baltic States and Finland (OrgBalt) and its purpose is to map the thickness of the organic layer on a national scale for the territory of Latvia. The mapping was done using machine learning methods and NFI sample plot data on peat layer thickness, ALS laser scanning data and other additional data were used as training data. As a result, a raster map was obtained, which depicts the depth of the peat layer in three different classes - No peat, peat layer thickness from 1 to 20 cm and peat layer thickness more than 20 cm. The accuracy of the machine learning classification algorithm reaches 0.88, while the kappa value is 0.74. Separately by different classes, the sensitivity of the model is 0.94 for the first class, 0.63 for the second class and 0.81 for the third class.

How to cite: Ivanovs, J. and Lazdiņš, A.: Mapping peat layer thickness using machine learning and aerial laser scanning data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17242, https://doi.org/10.5194/egusphere-egu23-17242, 2023.

Reliable determination of the soil organic carbon stock (SOCS) and its time trend at field scale is a key condition to value soil organic carbon (SOC) sequestration as a negative emission technology (NET) at farm level. Limiting the stock estimation to 30 cm depth is acceptable on the range of some decades (Balesdent et al., 2018). The carbon stock, however, is not directly estimated from the SOC content. SOC content must be multiplied by the bulk density (BD) of the corresponding layer. BD determination is time consuming and tedious to determine, and changes with time due to soil swelling with water, soil tillage, and changes in SOC. Therefore, the changes in SOCS must be monitored on an equivalent soil mass (ESM) basis, by referring to the sampled soil mass of the previous sampling rather than to a constant depth layer. Corrections of the mass, simplification of the soil mass determination overcoming the BD determination issue, as well as a simplified one-layer method have been proposed (Wendt and Hauser, 2013). However, this simplified ESM method requires the sampling and analysis of at least two layers for sampled mass correction. Moreover, the field volume percentage of the coarse (> 2 mm) fraction must be determined and removed from the sampled layer volume, which is not well documented. On the other hand, and to our best knowledge, private companies providing SOCS certificates sample the soils at constant depth using mechanical gauges that do not allow to control the quality of the extracted core. Finally, the errors associated with these different technical options needs to be clarified.

This study was performed using samples collected in 60 fields from different farms of the Swiss Leman-Lake region. It aimed at providing a full reliable methodology to determine SOCS at field scale, while solving the remaining issues, namely to determine the errors associated to the different parameters estimated and to simplify the ESM one-layer method to decrease the sampling and analytical costs. The minimum detectable change was determine (i) for sampling performed using the mechanical gauges at constant depth, (ii) for the ESM one-layer method as described in (Wendt and Hauser, 2013), (iii) the additional error introduced by coarse fraction estimation and gauge diameter and (iv) a simplification of the one-layer ESM method taking into account local average properties of the soil below the 0-30 cm sampled layer.

How to cite: Boivin, P. and Lemaître, T.: Determination of carbon stocks in arable land: errors, improvement of the one-layer equivalent soil mass method and associated minimum detectable change, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17576, https://doi.org/10.5194/egusphere-egu23-17576, 2023.

China has promised that CO2 emissions per GDP in 2030 would decrease by 60% to 65% than that in 2005, and proposed the goal of achieving carbon neutral by 2060. In order to fulfill these goals, Carbon Emissions Trading (CET) and Tradable Green Certificates (TGC) have been implemented in the power industry during the ‘13th five-year’ period. We firstly simulate the combined effects of TGC and CET on the electricity market from 2020 to 2026. Further, we build a policy synergy model to explore the optimization relationship between TGC and CET systems. The results show that, the power supply structure can be optimized under TGC and CET systems. The growth rate of CO2 emissions from the power industry will slow down, accelerating peaking CO2 emissions of the power industry. The national CO2 emissions reduction goal (1.185–1.037 tons /RMB 10,000 yuan by 2030) is expected to be achieved. There may be policy redundancy between TGC and CET systems. It is determined by how to set renewable energy objective and CET quota objective. Under multiple policy objectives, the key is to obtain the policy synergy intervals for staged optimization. Finally, we propose some suggestions on the improvement of TGC and CET mechanisms, and combined implementation and optimization of multiple emission reduction policies.

How to cite: Feng, T.: Induction mechanism and optimization of tradable green certificates and carbon emission trading acting on electricity market in China, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1993, https://doi.org/10.5194/egusphere-egu23-1993, 2023.

Energy system analysis has been widely used to imply technologically and economically plausible energy-system transition pathways for national net-zero emissions targets. Undermining the feasibility of such energy system analysis results are the highly-resolved mapping, sector-by-sector, of the timing and spatial distribution of changes in energy infrastructure, capital investment, employment, air pollution, land use, and other key outcomes at local level. A successful net-zero transition must be accomplished with supplementary supply of factors of production (e.g., human capital, natural capital, investment etc.) to enable such low-carbon transition. Using Princeton’s net-zero America study as example, we find that each net-zero pathway results in a net increase in energy-sector employment and delivers significant reductions in air pollution, leading to public health benefits that begin immediately in the first decade of the transition. We also conclude that each transition pathway features historically unprecedented rates of deployment of multiple technologies. Impacts on landscapes, incumbent industries and communities are significant and planning will need to be sensitive to regional changes in employment and local impacts on communities.

How to cite: Zhang, C.: Linking energy system analysis with factors of production analysis: A US case study, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3084, https://doi.org/10.5194/egusphere-egu23-3084, 2023.

EGU23-3817 | ECS | PICO | ERE1.5

The carbon cost of mitigating air pollutant emissions from coal-fired power plants in China 

Pengfei Zhang, Kuishuang Feng, Li Yan, Yaqin Guo, Bei Gao, and Jiashuo Li1
  • With the largest pollution-intensive coal-fired power plant (CFPP) fleet in the world, China has widely distributed air pollutant control devices (APCDs) to improve air quality. These APCDs are effective in mitigating air pollutants, at the same time, consume substantial carbon-intensive electricity from CFPPs. Nevertheless, the carbon cost of clean coal-fired power remains unexplored. Therefore, by collecting plant-level information, we quantified CO2 emissions induced by APCDs’ power consumption from China’s CFPPs. We show that from 2000 to 2020, CO2 emissions induced by APCDs in China’s CFPPs increased from 1.48 Mt to 51.7 Mt, and the ratio of power consumed by the APCDs to the total power generation increased from 0.12% to 1.19%. In 2020, the wet limestone-gypsum flue gas desulfurization device dominated the carbon emissions with a percentage of 80%, followed by the dust removal device’s 13% and denitration device’s 7%, respectively. Scenario analysis demonstrates that Inner Mongolia, Shanxi, and Shandong are the hotspots of APCD CO2 emissions in the future. The lifetime of CFPPs is an important factor affecting the scale of future APCD CO2 emissions. Our study underscores the urgency of a comprehensive assessment of environmental policies and urges the necessity of synergetic management of air pollutants and carbon emissions.

How to cite: Zhang, P., Feng, K., Yan, L., Guo, Y., Gao, B., and Li1, J.: The carbon cost of mitigating air pollutant emissions from coal-fired power plants in China, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3817, https://doi.org/10.5194/egusphere-egu23-3817, 2023.

EGU23-4023 | ECS | PICO | ERE1.5 | Highlight

Tracing metal footprints through global renewable power value chains 

Rao Fu, Kun Peng, Peng Wang, Honglin Zhong, Xi Liu, Kuishuang Feng, and Jiashuo Li

The globally booming renewable power industry has stimulated an unprecedented interest in metals as key infrastructure components. Many economies with different endowments and levels of technology participate in various production stages and cultivate value in global renewable power industry production networks, known as global renewable power value chains (RPVCs), complicating the identification of metal supply for the subsequent low-carbon power generation. Here, we use a value chain decomposition model to trace the metal footprints (MFs) and value-added of major global economies’ renewable power sectors. We found that the MFs of the global renewable power sector increased by 47% during 2005—2015. Developed economies occupy the high-end segments of RPVCs while allocating metal-intensive (but low value-added) production activities to less developed economies. The fast-growing demand for renewable power in developed economies is a major contributor to the embodied metal transfer increment within RPVCs, which is partly offset by the declining metal intensities in less developed economies. Therefore, it is urgent to establish a metal-efficient and green supply chain for upstream suppliers as well as downstream renewable power installers for transition in the power sector across the globe.

How to cite: Fu, R., Peng, K., Wang, P., Zhong, H., Liu, X., Feng, K., and Li, J.: Tracing metal footprints through global renewable power value chains, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4023, https://doi.org/10.5194/egusphere-egu23-4023, 2023.

EGU23-4171 * | PICO | ERE1.5 | Highlight

Material footprint assessment of hydropower plants 

Ling Shao, Yunlong Pan, Yuwen Chu, and Zi Wu

Hydropower is the largest renewable source of electricity generation. However, the construction and operation of hydropower plants may cause significant material footprints. This study provides a systems accounting framework for evaluating the life-cycle material footprint of a hydropower plant. It is based on the hybrid method as a combination of the process analysis and the input-output analysis. A case study for a typical pumped storage hydropower plant (NPSHP) is carried out to demonstrate the framework. 12 metals (bauxite and aluminum ores, copper ores, gold ores, iron ores, lead ores, nickel ores, PGM ores, silver ores, tin ores, uranium and thorium ores, zinc ores, and other non-ferrous metal ores) and 8 minerals (building stones, chemical and fertilizer minerals, clays and kaolin, gravel and sand, limestone & gypsum & chalk & dolomite, salt, slate, and other minerals) are included.  The results can be helpful to promote a sustainable energy transition by incorporating material planetary boundaries into renewable energy systems.

How to cite: Shao, L., Pan, Y., Chu, Y., and Wu, Z.: Material footprint assessment of hydropower plants, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4171, https://doi.org/10.5194/egusphere-egu23-4171, 2023.

Low-carbon power transition, key to combatting climate change, brings far-reaching effects on achieving Sustainable Development Goals (SDGs), in terms of resources use, environmental emissions, employment, and many more. Here we assess the potential impacts of power transition on multiple SDGs progress across 49 economies under six socio-economic-climate scenarios. We find that the low carbon power transition under Representative Concentration Pathway (RCP) 2.6 scenarios could lead to approximately 10% improvement in global SDG index score from 65.30 in 2015 to 71.62-71.64 in 2050. However, the improvement would be significantly decreased to 1.91%-4.98% and 3.42%-5.24% under RCP6.0 and RCP4.5 scenarios, respectively. Power transition could improve the overall SDG index in most developed economies under all scenarios while undermine their resources-related SDG scores. The power transition induced changes in international trade would improve developed economies’ SDG progress, but jeopardize that of developing economies which usually serve as resource hubs to meet the demand for low carbon power transition in developed economies. 

How to cite: Peng, K.: Low carbon transition of global power sector may enhance sustainable development goals, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4310, https://doi.org/10.5194/egusphere-egu23-4310, 2023.

EGU23-4592 | ECS | PICO | ERE1.5

Growing Terbium Shortage Urges Radical Green Mining of Heavy Rare Earths 

Wei Chen, Peng Wang, and Wei-Qiang Chen

China’s supply of terbium and other heavy rare earth elements (HREEs) are critical to global sustainable transition. However, their supply chain and corresponding bottlenecks remain unclear. Here we present the first deep-dive analysis of China’s terbium supply chain and trade flows from 1990 to 2018, as well as its future potential trends through 2040. We identify a growing terbium shortage along with its fast-increasing demand to meet various sustainable applications, particularly for electric vehicles (EVs) and wind power (nearly half in 2018). In sharp contrast to previous views, we uncover that the lack of available green mining technology under rigorous environmental regulations, rather than China’s production quota, is currently the main constraint of terbium supply, given only 25% of its quota was exhausted in 2018. Moreover, this supply gap is expected to increase six-fold over the next 20 years to meet China’s EVs and wind power ambitions. Our further analysis reveals the present widely-advocated approaches (including material substitution, reduction, and recycling), will alleviate only around 56% of such shortages, which urges radical green mining breakthroughs to overcome environmental constraints in both China and other HREEs supply countries.

How to cite: Chen, W., Wang, P., and Chen, W.-Q.: Growing Terbium Shortage Urges Radical Green Mining of Heavy Rare Earths, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4592, https://doi.org/10.5194/egusphere-egu23-4592, 2023.

EGU23-5194 | PICO | ERE1.5

Carbon footprint scenarios for electricity mix in China 

Jin Yang and Lin Tang

The biggest increase in carbon emissions took place in the power sector, accounting for more than 40% of global carbon emissions. Identifying critical sectors of carbon emissions in the upstream power sector and mapping out emission reduction pathways are core components of achieving supply chain-wide carbon reductions in China. However, the path to achieving supply chain-wide carbon reductions in China from the provincial perspective is still unclear. This study quantifies the embodied carbon emissions of different power generation technologies by region using a multi-regional input-output-based hybrid approach. The critical upstream sectors that indirectly drive or transport large amounts of carbon emissions through supply chains are identified using both consumption-based and betweenness-based methods. The changes in supply chain-wide carbon emissions of the power sector by region under different emission reduction policy scenarios are also examined. The results indicate that the solar power sector brings the highest carbon reduction benefits, with an average carbon intensity of 1.25 t/10000 yuan. Significant differences in embodied carbon intensity across provinces for the same type of power generation sector are observed, and there is a mismatch between current installation and carbon reduction targets in the coal-fired and wind power sectors. Critical sectors of carbon emissions in the upstream power sector are concentrated in the energy sector and energy-intensive sectors, while the electrical machinery and equipment sector is also key to alleviating environmental pressures as an important upstream carbon transmission sector. Besides, the implementation of the "Replacing Small Generation Units with Large Ones" policy at the provincial level, especially in northwest China, and “further enhancing the supply capacity of clean energy” can effectively promote the emission reduction of the whole supply chain in the power sector. The results presented in this paper may provide a reference for the provincial government to rationally plan future low-carbon transformation paths of the power sector.

How to cite: Yang, J. and Tang, L.: Carbon footprint scenarios for electricity mix in China, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5194, https://doi.org/10.5194/egusphere-egu23-5194, 2023.

EGU23-8314 | ECS | PICO | ERE1.5 | Highlight

Life-cycle CO2 and Air Pollutant Emission Assessment of China’s Cement Industry under Planetary Boundaries 

Xingrui Cai, Chaoyue Zheng, Jing Meng, and Xuejun Wang

China is the world’s largest cement producer and consumer, contributing 58% of the world’s total cement production in 2020. The cement industry in China is associated with 4–5% of China’s total energy production and contributes 10–15% of national total CO2 emissions, ranking second only to the power industry, and also significant air pollutant discharges such as SO2, NOx and particulate matter (PM). Since China’s energy and environmental policies for the cement industry usually focus on specific energy/environment effects and a single manufacturing process, this study described the cradle-to-gate lifecycle covariation relationship of these effects and analyzed the potential transgression magnitude to related planetary boundaries to assist in designing low carbon and pollution industrial transition in Chinese cement industry. The multi-regional decomposition analysis model, the LMDI decomposition, and the SDA method were employed to identify the driving factors such as energy intensity, manufacturing technology, economic structure, intermediate demand and structure, and total demand. We found that the Chinese cement industry not only causes massive emissions directly but also imposes environmental burdens on other sectors through up- and downstream supply chains, especially in eastern and central regions. Scope 1 and 2 emissions decreased sharply for CO2, SO2, and PM thanks to stricter environmental regulations, but Scope 3 emissions of CO2 increased by approximately 30%, contributed by energy intensity and economic structural change. Although total emissions basically presented decline trends, several national and regional planetary boundaries might be transgressed under downscaling principles based on population, and gross value added. This work improves our understanding of lifecycle carbon emissions and pollution and related total environmental burden in terms of planetary boundaries, thus offering references for the implementation of energy conservation and environment policies in the Chinese cement industry.

How to cite: Cai, X., Zheng, C., Meng, J., and Wang, X.: Life-cycle CO2 and Air Pollutant Emission Assessment of China’s Cement Industry under Planetary Boundaries, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8314, https://doi.org/10.5194/egusphere-egu23-8314, 2023.

EGU23-16498 | ECS | PICO | ERE1.5

Drivers of global carbon emissions 1990-2014 

Cuncun Duan

The identification of the drivers of carbon emissions is fundamental for carbon reductions at the national level. In this study, structural decomposition analysis (SDA) is applied to 112 countries in the world from 1990 to 2014. Carbon dioxide emissions are decomposed into six driving factors: population, fuel mix, energy intensity, production structure, consumption patterns, and consumption volume. Then, the contributions of five final consumers and the six driving factors to the total carbon dioxide emissions are quantified. Based on the CO2 emissions intensity and the CO2 emissions growth rates, 112 countries are classified into 4 groups and the effects of all driving factors vary significantly among groups. Energy intensity is the most significant factor that negatively influences the total carbon emission in all groups. Fuel mix and production structure show potential positive effects on reducing carbon emissions in Group 2 (e.g. the USA, Greece, Italy) and Group 3 (e.g. Germany, the UK, Sweden), but they increase the carbon emissions in Group 1 (e.g. China) and Group 4 (e.g. Indonesia, Thailand, Pakistan). Consumption volume results in a dramatic increase in the carbon emissions in all groups, which implies that the increasing purchasing power of households and government is the most notable obstacle to carbon dioxide mitigation. Population growth accelerates the carbon emissions in developing countries in Group 4. Thus, the race between household consumption volume growth and energy intensity reduction is vital for carbon emission mitigation in Group 4.

How to cite: Duan, C.: Drivers of global carbon emissions 1990-2014, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16498, https://doi.org/10.5194/egusphere-egu23-16498, 2023.

ABSTRACT

Metal pollution is a global environmental issue and considers one of the most serious problems in coastal environments. Present work aimed to document the distribution, ecological risk, and the potential sources of heavy metals (HMs) in coastal sediments of Ras Abu Ali Island, Arabian Gulf, Saudi Arabia. V, Fe, Sr, Al, As, Hg, Sb, Cd, Co, Mn, Ni, Zn, Cr, Pb, Cu were determined in 34 coastal sediment using Inductively Coupled Plasma - Atomic Emission Spectroscopy (ICP - AES) and several pollution indices, and multivariate analysis were applied. The lower HM levels were recorded in the medium to coarse sized samples in the northern part of the study area faced to the open sea. The average values of Ni, Zn, Cu, As, Pb, and Cr were less than the sediment quality guideline (SQG) and the background continental crust. Most applied pollution indices revealed minor enrichment, low contamination and low risk for all HMs, except Sr, which indicated extremely severe enrichment and very high contamination. Sr is incorporated in calcite and aragonite of the invertebrate skeletons and sorbed in hydrated form by clay minerals. The petrochemical wastes from nearby Al-Jubail industrial city, Zn refineries, and intensive use of phosphate fertilizers might be the potential anthropogenic sources of Sr in the study area.

Keywords: Heavy metals, Pollution index, Coastal sediment, Strontium, Ras Abu Ali Island.

 

How to cite: Alkahtani, K. and El-Sorogya, A. S.: Contamination and environmental risk assessment of heavy metals in coastal sediments of Ras Abu Ali Island, Saudi ArabiaKhaled Al-Kahtanya and Abdelbaset S. El-Sorogya, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-54, https://doi.org/10.5194/egusphere-egu23-54, 2023.

EGU23-1411 | ECS | Orals | ERE1.7

What about human behavior? The case of urbanization and rice in Africa 

Koen De Vos, Charlotte Janssens, Liesbet Jacobs, Benjamin Campforts, Esther Boere, Marta Kozicka, Petr Havlík, Lisa-Marie Hemerijckx, Anton Van Rompaey, Miet Maertens, and Gerard Govers

Concurrent with an extensive population growth, the African continent has experienced a vast urbanization trend over the last decades. In 2000, around 35% of the population resided in urban areas. By 2020, this share has increased to around 44% and is projected to increase even further by 2050 following the Shared Socioeconomic Pathways (SSP) scenarios. Besides an important effect on local land use through urban expansion, this also affects food systems by shifting dietary patterns away from traditional diets towards imported or convenient goods. This is particularly the case for rice, which is predominantly imported from Southeast Asia, India, or Pakistan, and is gaining in popularity in African urban diets because of the low effort needed for cooking or storage – giving it a strong advantage over other staple crops. This dietary shift will alter trade dynamics, increase the pressure on local resources such as land, water, and fertilizer use, and subsequently also on biodiversity. In studies investigating the influence of urbanization, either the direct effect of urban expansion on land cover or the effects of dietary changes on demands are investigated, but rarely a combination or comparison of both. Particularly in impact studies or applications that focus on the synergy between water, land, and food-related issues, the dimension of human behavior, such as consumer preferences, is often overlooked.

In this study, we provide an initial projection of the expected future effects of both sprawl and shifting preferences for rice caused by urbanization on rice availability, land – and input use, rice-specific emissions, and trade dynamics. By combining micro-level data from household surveys stemming from the Living Standards Measurements Study (LSMS) with the partial equilibrium Global Biosphere Management Model (GLOBIOM) at an African scale, we were able to identify the relative contribution of land cover effects stemming directly from urban expansion and indirectly from dietary shifts caused by rural-urban migration and a divergence in income between urban and rural areas.

We indicate that while urban expansion only has a limited effect at the continental scale, the omission of any dietary shifts caused by urbanization substantially underestimates projections of African rice demand (by around 8% under an SSP2-scenario). This also results in subsequent underestimations of impacts on land use, trade dynamics, and rice-specific methane emissions. By this, our study exemplifies that consumer preferences are an essential component to understanding urbanization impacts, and that, by extension, human behavior is important to consider in impact and nexus studies.

How to cite: De Vos, K., Janssens, C., Jacobs, L., Campforts, B., Boere, E., Kozicka, M., Havlík, P., Hemerijckx, L.-M., Van Rompaey, A., Maertens, M., and Govers, G.: What about human behavior? The case of urbanization and rice in Africa, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1411, https://doi.org/10.5194/egusphere-egu23-1411, 2023.

EGU23-2258 * | Orals | ERE1.7 | Highlight

Feeding 10 billion people and achieving negative emissions within Planetary Boundaries – insights from global modelling 

Dieter Gerten, Johanna Braun, Jannes Breier, Sibyll Schaphoff, Fabian Stenzel, and Constanze Werner

This talk will present key results from a suite of comprehensive simulations performed with a configuration of the LPJmL biosphere model able to represent the dynamic and spatially detailed status of terrestrial Planetary Boundaries (PBs, i.e. guardrails describing maximum tolerable levels of land-system change, biosphere degradation, freshwater use and nitrogen leaching to avoid Earth system destabilisation).

An application of the PB simulator addresses the question how much food could be supplied globally while respecting these multiple PBs, and to what degree this supply could be increased through transformative actions towards more sustainable food production and consumption patterns. A further application demonstrates the potential to achieve ‘negative emissions’ through dedicated biomass plantations (as a measure to limit transgression of the climate change PB) within these PBs. A main finding is that almost half of current food production is environmentally unsustainable in that it depends on PB transgressions. Subsequent simulations show that the same amount of food presently produced under these unsustainable conditions, and even up to about 50% more, could be provided without violating the PB constraints in any place. This would be sufficient to feed around 10 billion people. The required underlying transformations of the food system are rather radical though: ambitious prerequisites are more efficient use of freshwater and nitrogen fertiliser in many places, reallocation of rainfed and irrigated cropland to areas where that would still be acceptable from a PB point of view, halving of food losses, dietary shifts towards lower shares of animal-based products, and (importantly) combinations thereof.

While this poses grand challenges regarding transformation of world agriculture and optimisation of resource use, currently debated methods to achieve ‘negative emissions’ via large-scale deployment of biomass plantations are likely to require large areas as well as freshwater and nutrients on their own. We will show that the option space for such measures is therefore actually very limited, if the terrestrial PBs were to be maintained. In addition, PB interactions such as ongoing and aggravating climate change including more frequent and intense droughts may seriously affect both the food production and negative emissions potentials. A conclusion is that quantitative robust understanding of these major tradeoffs and dilemmas requires even more comprehensive and integrated nexus studies bringing together the relevant aspects in a consistent PB modelling framework, not least also accounting for the social dynamics underlying the required transformations in the real world.

How to cite: Gerten, D., Braun, J., Breier, J., Schaphoff, S., Stenzel, F., and Werner, C.: Feeding 10 billion people and achieving negative emissions within Planetary Boundaries – insights from global modelling, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2258, https://doi.org/10.5194/egusphere-egu23-2258, 2023.

Arsenic (As) pollution has become a global concern due to its toxic and carcinogenic nature. Even at relatively low concentrations, arsenic can cause acute and chronic human toxicity. In the current study, samples of groundwater, soil at three depths (top, 50cm, and 150 cm), and grains were collected from a humid sub-tropical region in India encompassing Ballia, Deoria, and Mau districts in the state of Uttar Pradesh. All the samples were analyzed for arsenic employing Inductively Coupled Plasma Mass Spectrometry (ICPMS-MS). 60.3% of groundwater samples exceeded the Bureau of Indian Standards (BIS) permissible limit of 10 μg/l. 40% of soil samples were above the mean background concentration for arsenic in the soil as indicated by the Indian Agricultural Research Centre (IARC), i.e., 5 mg/kg. Further, Human Health Risk Assessment (HHRA) was evaluated in four stages: hazard identification, dose-response assessment, exposure assessment, and risk characterization. HHRA estimates the nature, magnitude, and probability of arsenic impacts in the present and the future. Chronic Daily Intake rate (CDI) was determined to assess the exposure, which depends on the mobility of arsenic in groundwater→soil→crop system. The gradual increase in arsenic contamination in groundwater, mostly used in irrigation, finds its way to the food chain either via drinking or cooking, which is a matter of concern for humans. For risk assessment, Total cancer risk (TCR) and Hazard Index (HI) were computed. Finally, the study estimated the cancerous and non-cancerous risks from arsenic toxicity in groundwater-soil-crop system to human adults and children. The cancerous risk for arsenic contamination was in the order of adults>children due to long-term exposure to arsenic by adults. In contrast, the non-cancerous risks for adults and children exceeded the threshold value of 1 provided by the U.S. Environmental Protection Agency (USEPA), specifying a high health risk rate (children>adults). Apparently, children are more sensitive to chemicals in comparison to the adaptability of adults, and hence, they are most affected. It is envisaged that studies like this, which examine scenarios of elevating probabilities of health risks in children and adults from arsenic-contaminated groundwater, soil, and crops, would enable more rational and decisive actions from the concerned stakeholders for arsenic management in the future.

How to cite: Dhamija, S. and Joshi, H.: Assessment of Human Health Risks from Arsenic Contamination in Groundwater-Soil-Crop System of a Humid Sub-Tropical Region in India, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2526, https://doi.org/10.5194/egusphere-egu23-2526, 2023.

EGU23-3963 | Posters virtual | ERE1.7 | Highlight

A Resource Nexus concept - Definition, design, and practice 

Floor Brouwer

The nexus has gained importance in assessing interlinkages between related resources and is critical to achieving broader policy goals such as the Sustainable Development Goals (SDGs) or targeted objectives related to biodiversity and climate. Creating awareness of such interactions offers a basis to seek synergies that might be created. Guided by an extensive literature review and a consultation of nexus experts, the presentation will summarize the main features of the nexus and an overview of essential resources that are critical for consideration in a Resource Nexus concept. Definitions of the nexus provided in the literature typically relate to focused and often limited approaches. Moreover, some steps are presented to advance the concept in Resource Nexus assessments. In light of the latter, an effort is made to propose a more robust definition of the Resource Nexus for its application and operationalization for policy support.

 

How to cite: Brouwer, F.: A Resource Nexus concept - Definition, design, and practice, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3963, https://doi.org/10.5194/egusphere-egu23-3963, 2023.

EGU23-4253 | ECS | Posters on site | ERE1.7

Water-Energy-Food Nexus Analysis at Basin Level to Improve the Resources Availability and Accessibility Sources 

Krishna Mondal, Chandranath Chatterjee, and Rajendra Singh

Water, Energy and Food (WEF) are considered global security, prosperity, and equity pillars. These resources are fundamentally linked: food production requires both water and energy; pumping, treating, and transporting water requires energy; energy production requires water, which faces numerous challenges, including growing population density, rapid urbanisation, economic growth, poverty, hunger, changing diet habits and climate changes. In this study, we have developed a spatially distributed (block-scale) WEF-Nexus model with the help of the Modified Pardee-RAND Water-Energy-Food Security Index (MPRWEFSI) equation to meet the basin-scale WEF challenges. The Pardee RAND WEF security index has been modified by considering the industrial and agricultural water requirement, renewal energy and water sources, modern farm equipment uses, hunger index, etc. The developed model can produce the resources availability, accessibility and security indexes. We have tested the model in the Kangsabati river basin for 2011. The estimated values of the water, energy, and food subindex reveals that the Jaypur block (1.0) had the highest water security, the Bipur-II block (0.865) had the highest energy security, and the Jhargram block (1.0) had the highest food security. Conversely, the Jhalda-II block (0.65) has the lowest water security, the Kharagpur-I block (0.52) has the lowest water security, and the Purulia-I block (0.56) has the lowest water security. Furthermore, Jaypur (0.92) and Jhalda-II (0.63) had the highest and lowest overall WEF nexus index. The result also shows that the basin's water, energy, and food availability indexes are 0.88, 0.91 and 0.65, accessibility indexes are 0.92, 0.60, and 0.98, and security indexes are 0.89, 0.73 and 0.79, respectively. The overall WEF nexus Index of the basin is 0.80. Although the availability and accessibility of resources are in a considerable range, different schemes and policies are needed to achieve a hundred per cent resources availability, security, and security. Likewise, basin-scale WEF management will ensure better management of WEF resources holistically and equitably. This study will be helpful in influencing the policy and resource planning process.

Keywords: Resources Availability, WEF-Nexus, Pardee RAND, Basin-scale

 

How to cite: Mondal, K., Chatterjee, C., and Singh, R.: Water-Energy-Food Nexus Analysis at Basin Level to Improve the Resources Availability and Accessibility Sources, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4253, https://doi.org/10.5194/egusphere-egu23-4253, 2023.

EGU23-6277 | ECS | Posters virtual | ERE1.7

Integrating Water-Energy-Food-Ecosystems (WEFE) Nexus Indicators and SDGs 

Chrysaida-Aliki Papadopoulou and Nikolaos Mellios

The Water-Energy-Food-Ecosystems (WEFE) nexus represents a concrete system the components of which are inextricably linked with direct and indirect interlinkages. Complexity is the main characteristic describing this complicated system of interactions that affects the effective management of available resources at both physical and policy level. Thus, sectorial approaches have been proved rather insufficient and a holistic rationale is now suggested, placing emphasis on the systemic nature of the WEFE nexus. The achievement of SDGs and relevant sub-targets is also significantly affected by the sustainable use of resources as the core dimension of SDGs reflects the urgent need for the adoption of a more sustainable and resource-efficient pattern of development. This study elaborates on WEFE nexus indicators supporting sustainability in line with the priorities having been set by SDGs. Such indicators focus on issues strongly related to the several WEFE sectors such as flood alleviation, hydropower production, exploitation of biomass, rural/agricultural development, water quality protection, securing of environmental flow, food production and land use changes under climate change conditions. Moreover, the spatial dimension is taken into consideration as, according to the literature, the successful implementation and achievement of SDGs presupposes their specialization and adaptation to local needs and characteristics (e.g. country or regional level). Land use change in time (%), GHG emissions emanating from agriculture and livestock (%), crop yields (cereals, vegetables, etc.) (%), use of pesticides/fertilizers (kg) and water available for environmental flow (%) are among the proposed indicators. It should be mentioned that such indicators correspond to more than one SDG as emphasis was placed on covering as many aspects of SDGs as possible.

How to cite: Papadopoulou, C.-A. and Mellios, N.: Integrating Water-Energy-Food-Ecosystems (WEFE) Nexus Indicators and SDGs, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6277, https://doi.org/10.5194/egusphere-egu23-6277, 2023.

EGU23-8580 | Orals | ERE1.7

Doubling protected land area may be inefficient at preserving the extent of undeveloped land and could cause substantial regional shifts in land use 

Alan Di Vittorio, Kanishka Narayan, Pralit Patel, Katherine Calvin, and Chris Vernon

Projection of land use and land cover change is highly uncertain yet drives critical estimates of carbon emissions, climate change, and food and bioenergy production. We use new, spatially-explicit land availability data in conjunction with a model sensitivity analysis to estimate the effects of additional land protection on land use and cover. The land availability data include protected land and agricultural suitability and are incorporated into the Moirai land data system for initializing the Global Change Analysis Model (GCAM). Overall, decreasing land availability is relatively inefficient at preserving undeveloped land while having considerable regional land use impacts. Current amounts of protected area have little effect on land and crop production estimates, but including the spatial distribution of unsuitable (i.e., unavailable) land dramatically shifts bioenergy production from high northern latitudes to the rest of the world, as compared to uniform availability. This highlights the importance of spatial heterogeneity in understanding and managing land change. Approximately doubling current protected area to emulate a 30% protected area target may avoid land conversion by 2050 of less than half the newly protected extent while reducing bioenergy feedstock land by 10.4% and cropland and grazed pasture by over 3%. Regional bioenergy land may be reduced (increased) by up to 46% (36%), cropland reduced by up to 61%, pasture reduced by up to 100%, and harvested forest reduced by up to 35%. Only a few regions show notable gains in some undeveloped land types of up to 36%. Half of the regions can reach the target using only unsuitable land, which would minimize impacts to agriculture but may not meet conservation goals.

A.V. Di Vittorio, K.B. Narayan, P. Patel, K. Calvin, C.R. Vernon (2022). Doubling protected land area may be inefficient at preserving the extent of undeveloped land and could cause substantial regional shifts in land use. GCB Bioenergy, 00:1-23. http://doi.org/10.1111/gcbb.13016

How to cite: Di Vittorio, A., Narayan, K., Patel, P., Calvin, K., and Vernon, C.: Doubling protected land area may be inefficient at preserving the extent of undeveloped land and could cause substantial regional shifts in land use, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8580, https://doi.org/10.5194/egusphere-egu23-8580, 2023.

EGU23-10381 | ECS | Orals | ERE1.7

Spatial patterns of land use & land cover changes surrounding Colombian water reservoirs 

Caroline Salomão, Jonas Alsleben, Philippe Rufin, and Patrick Hostert

Hydropower dams can induce spatial and temporal changes in land and water systems in terms of resource access and use. Regardless of the main purpose of these dams (that is, to produce energy), analyzing these changes by the lenses of the water-energy-food nexus helps us to identify the synergies and trade-offs between these components in the watershed context. Changes  in land & water systems happen in different times (dam’s construction and operation), spatial scales and, in many cases, are also influenced by national political-economic context. Colombia is moving towards peace agreements in recent years, and this process already showed impact in the patterns of land and water uses, especially by agricultural systems. This new scenario can create or consolidate some local and national socioeconomic characteristics, adding inequalities beyond the dam’s construction. This work focuses on the land cover and land use transitions surrounding two dams in the Magdalena basin, Betania-Quimbo and Hidrosogamosso. This basin is responsible for 70% of the national energy production, it concentrates the production of important food/energy value chains for the local and global market and possess high biodiversity. Both dams were built in 2009 and started operations after 2015, so Landsat satellite images were used to build the land use & cover maps in 2009, 2015 and 2021 for 7 classes (rice, palm oil, pasture, forest, water surface, temporary and permanent crops and others). Due to the intensity of clouds and high altitudes, Colombia is one of the most difficult regions in the world to build these maps, and for this reason global, or even local, mapping available turn out to be unrealistic. A random forest model was chosen, and, as variables, indexes and spatial temporal metrics using 176 bands in total. To extract the pixel information for training and testing the model, a stratified random sample was run using different secondary maps, and after that, we used Google Earth for visual verification (1196 observation for all years). For the accuracy assessment just the sample from the current year was used. The model was run in Google Earth Engine. The model achieved a similar overall accuracy in all years (79%), and for certain agricultural systems a high accuracy, such as the case of palm oil with100% accuracy in 2021 and 2015, despite reaching 70% in 2009. Accuracy for rice was also high: 95%, 84% and 88% in 2021, 2015 and 2009 respectively. Pasture achieved a medium accuracy: 78% (2021): 83% (2015); and 71% (2009). Water surface achieved a high accuracy.For water surface: 100% in 2021 and 2015, and 97% in 2009. The Forest category reached a medium-high accuracy: 81%, 88% and 77% in 2021, 2015 and 2009 respectively. Land use and Land cover maps of areas impacted by dams is of high importance to support decisions that will be implemented via instruments such as Basin Management Plans or compensatory schemes.

How to cite: Salomão, C., Alsleben, J., Rufin, P., and Hostert, P.: Spatial patterns of land use & land cover changes surrounding Colombian water reservoirs, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10381, https://doi.org/10.5194/egusphere-egu23-10381, 2023.

EGU23-10490 | ECS | Orals | ERE1.7

Integrating SWAT and Participatory System Dynamics Modelling for analyzing the WEF Nexus: the Tarquinia plain case study 

Marwah Yaseen, Ivan Portoghese, Raffaele Giordano, Alessandro Pagano, Vito Iacobellis, Silvia Vanino, Tiziana Pirelli, Stefano Fabiani, and Valentina Baratella

A safe access to water, energy, and food that does not impact the state of ecosystems and natural resources are needed for human well-being as well as for economic and environmental sustainability. As natural resources availability is threatened by a multiplicity of stressors (including e.g. climate change), the interconnections and interdependencies among resources become stronger and more critical to investigate. Sustainable resources use thus requires a holistic ‘Nexus’ approach, which can contribute to reduce conflicts among sectors and create more synergies compared to a silo approach to water, energy, food, and ecosystems realms.

The importance of active stakeholder engagement in the management of natural resources is also increasingly acknowledged, although there is a lack of participation in policy planning phases and in the decision-making processes. When models are developed to support resources planning and management, the involvement of stakeholders from early stages is crucial to include their knowledge in model building, to tailor the model according to their needs, and to ensure that the potential implications of actions are correctly represented. This ultimately guarantees ownership of modelling results.

System Dynamics Modelling (SDM) includes a multiplicity of tools and methods to describe, model, simulate, and analyse dynamically complex systems taking jointly into account both scientific information (e.g. from sectoral models) and stakeholders’ knowledge and perception. SDM has gained attention, in the recent scientific literature, in Nexus studies. Specifically, the use of qualitative SDM tools (such as Causal Loop Diagrams – CLDs) allows the analysis of the system behaviour based on a conceptual (mental) model focusing on linkages and feedback loops. Quantitative simulation models (stock-and-flow diagrams) use equations to quantify linkages between different types of variables over time. Stock and flow diagrams benefit from the information deriving from sectoral models, such as hydrological models, although the integration with such models has been limitedly explored to date.

The present work proposes an approach based on the use of SDM tools for the development of an integrated model supporting the analysis of a complex Nexus system. Particular attention is given to the analysis of the interdependencies between water quantity, quality, and management, and to the implications of irrigation and agricultural practices for the state of the environment. The main elements of innovation are: i) the coupling between SDM, built in a participatory form with the key stakeholders in the study area, and the Soil and Water Assessment Tool (SWAT); ii) the combination scientific and stakeholder knowledge to appraise the socio-economic and ecological effects of the various management situations co-designed with the stakeholders. Reference is made to one of the pilot areas of the LENSES project (PRIMA Foundation, GA n. 2041), namely the Tarquinia plain watershed, located in Central Italy, an area with a relevant environmental value, but characterized by intensive irrigated agriculture with severe impacts on water and ecosystems.

 

How to cite: Yaseen, M., Portoghese, I., Giordano, R., Pagano, A., Iacobellis, V., Vanino, S., Pirelli, T., Fabiani, S., and Baratella, V.: Integrating SWAT and Participatory System Dynamics Modelling for analyzing the WEF Nexus: the Tarquinia plain case study, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10490, https://doi.org/10.5194/egusphere-egu23-10490, 2023.

EGU23-11213 | ECS | Orals | ERE1.7

Water- Energy- Food- Ecosystem Services (WEFE) nexus assessment in the context of climate change: a literature review and conceptual model development for the Adige River basin (Italy). 

Beatrice Sambo, Silvia Cocuccioni, Fabio Carnelli, Stefano Terzi, Anna Sperotto, Silvia Torresan, Massimiliano Pittore, Marc Zebisch, and Andrea Critto

Water, Energy, Food and Ecosystems are inextricably linked within a complex system (“the WEFE Nexus”) dominated by interactions, feedback, and scale effects. The analysis of the WEFE nexus is increasingly relevant in both academic and policy discussion; since its systematic approach could contribute addressing some fundamental EU challenges and policies, supporting the achievement of multiple Sustainable Development Goals.

Existing studies are still focused on dual interactions between sectors (e.g. water-energy, water-food) and don’t fully consider the ecosystem services components, despite their importance is widely recognized. There are still some challenges on how to use heterogeneous and sector-specific data and large climate projection datasets within the nexus concept.

The aim of this analysis is to explore how the WEFE nexus components and their interactions have been examined in recent scientific literature, and how they can be conceptualized in the Adige River basin (Italy), in order to identify synergies and trade-offs among different resources and uses.

Firstly, an in-depth state-of-the-art review on the main methodologies which allow the full integration of ecosystem services and climate change effects was undertaken for publications in the time frame 2010-2022. The review focused on i) how complex interlinkages among the sub-sectors of the WEF nexus and Ecosystem Services are modeled and how researchers operationalized these interlinkages in current conceptual frameworks; ii) how the spatial (from source to sea) and temporal dynamics of nexus are changing under future scenarios of climate and socio-economic changes; iii) which are the recent applied tools, methods and models which allow to operationalize the WEFE nexus behaviors and to support decision-making policies. The review shows that the interrelations among the WEFE sectors within conceptual frameworks are mainly modeled by qualitative methods (e.g. causal loops, multi-criteria decision analysis); while the spatio-temporal dynamics are mainly assessed by quantitative approaches (e.g. System Dynamics, Bayesian Networks). Furthermore, ecosystem services and climate change are mainly considered as external drivers influencing the WEF nexus sectors rather than a nexus component.

Based on the collection and review of peer-reviewed, grey literature and newspaper articles dealing with the water management topic, a first conceptualization of the sectors involved in the WEFE Nexus for the Adige River basin was performed. The framework, finalized with expert-based discussions in the context of two local stakeholders’ workshops, allowed the identification and qualitatively characterization of the relations among the WEFE sectors as well as the pressures by external components on the system (i.e. climate and socio-economic drivers). Five levels of conceptualization have been conceived to represent the main dynamics for each nexus’ sectors (i.e. water, energy, food, and ecosystem services) and their overall interactions.

The results of the analysis are part of the Horizon2020 project NEXOGENESIS, and pave the way for the application of a complex science methodology able to disentangle the role of ecosystem services and climate change in the frame of the nexus approach

How to cite: Sambo, B., Cocuccioni, S., Carnelli, F., Terzi, S., Sperotto, A., Torresan, S., Pittore, M., Zebisch, M., and Critto, A.: Water- Energy- Food- Ecosystem Services (WEFE) nexus assessment in the context of climate change: a literature review and conceptual model development for the Adige River basin (Italy)., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11213, https://doi.org/10.5194/egusphere-egu23-11213, 2023.

EGU23-11836 | ECS | Orals | ERE1.7

Participatory System Dynamics modelling for Water-Energy-Food Nexus characterization and for supporting the analysis of management measures 

Virginia Rosa Coletta, Alessandro Imbò, Alessandro Pagano, Umberto Fratino, and Raffaele Giordano

There is a growing awareness on the existence of dynamic interdependencies between the Water-Energy-Food sectors that cannot be ignored in identifying sustainable sectoral and cross-sectoral policies. In addition, the increasing demand for resources creates trade-offs that are exacerbated by the impacts of climate change, such as drought and flood with increasing frequency and magnitude. The Water-Energy-Food Nexus approach is a powerful concept to address the interrelationships of resource systems and move towards better coordination and utilisation of natural resources, considering existing trade-offs and promoting positive synergistic impacts. However, the incorporation of this approach into policies is making slow progress. This means that a gap exists between science (Nexus thinking) and policy (Nexus doing). 

The present work, carried out in the framework of the REXUS project (H2020, GA 101003632), aims to develop a process, strongly based on the use of participatory approaches, to support decision‐makers in designing sustainable and actionable forward-looking solutions that increase resilience across sectors. Integrated modelling based on System Dynamics is used for this purpose. In fact, it i) accounts for real-world complexities; ii) allows for future scenarios development and analysis, with clear options for policymakers; iii) allows for the integration of stakeholders’ knowledge.

Specific reference is made to one of the REXUS pilots, namely the Isonzo‐Soca watershed between Italy and Slovenia, for which current cross‐border flow regulation agreements are insufficient to guarantee a good status of ecosystem services in the Italian territory. The participatory System Dynamics modelling approach is combined with results of sectoral models, hydropeaking indicators, and ecosystem services indicators for a clear framing of the problem and its effects on the system. Through stakeholder engagement, some strategies for limiting sectoral conflicts are co-designed and fed into the System Dynamics simulation model to assess their effects on the system - and on different aspects (social, environmental, economic, etc.) - under various multidimensional future scenarios. The approach, organised in several steps, is based on a common framework replicable in different study contexts.

How to cite: Coletta, V. R., Imbò, A., Pagano, A., Fratino, U., and Giordano, R.: Participatory System Dynamics modelling for Water-Energy-Food Nexus characterization and for supporting the analysis of management measures, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11836, https://doi.org/10.5194/egusphere-egu23-11836, 2023.

EGU23-15793 | ECS | Orals | ERE1.7 | Highlight

Modelling The Water-Energy-Food-Ecosystem Nexus Using Data-Driven Methods 

Elise Jonsson, Claudia Teutschbein, Thomas Grabs, Andrijana Todorovic, Andreina Francisco, and Malgorzata Blicharska

Attaining resource security in the water, energy, food, and ecosystem (WEFE) sectors is paramount in order to fulfill many of the sustainable development goals. To obtain a holistic understanding of this WEFE nexus and assess the impacts of policy decisions, climate change, and other interventions, a system dynamics approach to modelling has been encouraged. Due to the multiscale, nonlinear nature of this nexus and a recent data deluge in the WEFE sectors, we propose the use of data-driven methods, which rely on dimensionality reduction and machine learning algorithms to find low-rank patterns and parsimonious models in big data sets. As these methods have proven highly successful within other scientific disciplines, we evaluate the prospect of using a data-driven approach to address key issues in nexus research based on analogous case studies from these disciplines. Specifically, we address three key issues with nexus modelling: model discovery, extreme events, and scenario analysis. We first consider how to identify nonlinear dynamical equations from chaotic, noisy, multiscale, and variable-deficient measurements using algorithms like SINDy and HAVOK, which have already been employed on a multitude of physical, biological, and chemical systems. We then investigate how to model the cascading impacts of extreme events on the nexus based on data-driven models of disease outbreak, as well as rapid model recovery after an unprecedented extreme event. Finally, we look into how to employ data-driven control, using case studies in flight control and drug intervention modelling, for the purpose of assessing how policy decisions, climate change, or population growth may be evaluated when modelling the nexus. This can provide tools for stakeholders to see what systemic impacts their decisions might have, and how they can attain synergies between the WEFE sectors. While many studies have conceded that nexus modelling is highly individualized based on the selected region, sectors, and data availability, this overview highlights that a generalized systematic approach to nexus modelling may still be possible, despite these challenges.

How to cite: Jonsson, E., Teutschbein, C., Grabs, T., Todorovic, A., Francisco, A., and Blicharska, M.: Modelling The Water-Energy-Food-Ecosystem Nexus Using Data-Driven Methods, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15793, https://doi.org/10.5194/egusphere-egu23-15793, 2023.

EGU23-16010 | ECS | Posters on site | ERE1.7

Gender gaps in the Water-Energy-Food and Ecosystems Nexus 

Bianca Maria Rizzo, Enrica Caporali, and Xenia Schneiderand

Water, energy, food and ecosystems are four elements of paramount importance in achieving global human well-being leading to poverty reduction and sustainable social and economic development.

New global challenges brought about by increasing resource scarcity, climate change and environmental degradation are leading to an ever-increasing tightening of living conditions for men and women. 

These difficulties exacerbate conflicts, damaging economic development and leading to the death and forced displacement of millions of people each year. Women are the most affected by all these dramatic situations because they exacerbate gender inequalities and reinforce gender gaps. 

At the same time, it is widely recognized that there is a strong relationship between gender and sustainability in consumption, food production and ecosystem management.  

A Water-Energy-Food and Ecosystems Nexus approach which considers gender issues as important elements of the socio-economic environment, is proposed here for a sustainable management of resources. Men and women are affected differently by the lack of resources and have different roles in using and managing them, so it is crucial to have a gender perspective and to investigate gender issues while transitioning to WEFE-Nexus..

The approach is based on the analysis of 1) factors that contribute to a situation of gender inequality and 2) gender issues that impair a holistic transition towards WEFE-Nexus., i.e., a situation in which men and women do not have the same rights, responsibilities, and opportunities regarding the use and management of WEFE resources.

A thorough understanding of gender issues at various levels requires gender-disaggregated data. Only with this kind of data can policy makers be aware of the existing situation and can design gender-sensitive policies and strategies. In addition, gender-specific datasets linked to WEFE-Nexus are important to understand what differences arise from gender-specific productive roles, different perspectives of resources, access, and decision-making mechanisms with respect to resource management and use.

The preliminary analysis developed on 4 Mediterranean countries, namely Italy, Spain, Egypt, and Tunisia, in addition to a different availability of gender disaggregated data, reveals a significant gender gap in decision-making in the water, energy, food, and ecosystem sectors. All are dominated by men, especially in the most relevant job positions. This means that women are hardly involved in shaping policies or innovative resource management systems whose lack affects them most. The root cause of these gaps has been identified as a lack of awareness of the topic. Gender issues are considered irrelevant to the achievement of sustainable resource management. This often causes an underestimation of the effects that gender dynamics have on the achievement of this outcome. 

Having scientists who are aware of gender issues in their field and able to understand and analyze them in different contexts is the first step to having research that makes a real contribution to achieving gender equality by providing gender-disaggregated data and gathering the perspectives of all relevant actors and actresses.

How to cite: Rizzo, B. M., Caporali, E., and Schneiderand, X.: Gender gaps in the Water-Energy-Food and Ecosystems Nexus, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16010, https://doi.org/10.5194/egusphere-egu23-16010, 2023.

With increased water scarcity due to anthropocentric and natural causes, the trade-offs and synergies intrinsic to efficiently allocating water resources to various competing uses have become more polarized. Realizing the importance of an integrated approach in water governance, the Water-Energy-Food-Ecosystems (WEFE) Nexus can be used as a multi-level and cross-sectoral approach that advocates the EU water economy and, in addition, relies on ecological and social considerations. The goal of this work is to propose, design and foster the adoption of integrated, innovative and inclusive Nexus-smart water governance schemes and institutional settings to promote a secure water future in the EU, resilient to climate change. This work follows an evidence-based approach to propose, assess and optimize a set of WEFE Nexus smart methods in six different case studies reflecting various cross-sectoral, multi-level and multi-stakeholder water governance contexts. To achieve this goal and monitor water governance in the EU we provide a set of Nexus-smart socio-economic and environmental indicators that reflect the cross-sectoral and multi-level nature of water use.  We also propose and develop economic instruments and business models that support robust water management under cross-sectoral competition. 

How to cite: Vrachioli, M.: Resilient water governance under climate change within the WEFE Nexus (RETOUCH Nexus project), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16792, https://doi.org/10.5194/egusphere-egu23-16792, 2023.

EGU23-741 | ECS | Posters on site | ERE1.8

Trade-driven relocation of Greenhouse gas emission in India 

Shekhar Goyal and Udit Bhatia

The green revolution enhances crop yield, significantly contributing to many low-income countries' socio-economic development. However, increasing crop yields might raise crop residue burning, leading to adverse human health and environmental consequences. Recent studies show that international trade affects the global distribution of Agricultural Greenhouse Gas (AGHG) emissions, air pollution, and public health. Domestic Interstate Trade (DIT) has similar effects on AGHG within the country but has yet to be comprehensively investigated. Large-scale open burning of crop residue further contributes to severe haze pollution in Indian cities, affecting national climate goals. Given the critical importance of food security, further reducing AGHG remains challenging. While there has been an increasing focus on AGHG, limited attention has been paid to its consumption-based drivers. We found that DIT exacerbates the health burdens of air pollution in Indian states based on regional wind patterns. Here, by tracing the consumption-based accounting of emissions, we evaluated the consequences of agricultural DIT on the emission potential of India. Our preliminary results show that though residual crop burning pollutes nearby regions, it is driven by consumption-based demands. These results suggest that DIT structure readjustment according to emission losses is needed for India while targeting trade intensification strategies. Our findings are relevant to national efforts to reduce emission losses in India. 

 

How to cite: Goyal, S. and Bhatia, U.: Trade-driven relocation of Greenhouse gas emission in India, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-741, https://doi.org/10.5194/egusphere-egu23-741, 2023.

EGU23-1556 | ECS | Orals | ERE1.8

Key trends and opportunities in water footprints of crop production 

Oleksandr Mialyk, Martijn J. Booij, Rick J. Hogeboom, and Markus Berger

Crops consume the majority of green and blue water worldwide which, in many areas, affects water availability and state of ecosystems. Hence, it is important to understand the recent dynamics in crop water footprints (WF, m3 t-1). Here, we analyse the global WF of more than 150 crops during 1990–2019 simulated with a global gridded crop model ACEA at 5 x 5 arc minute resolution. Our results indicate the overall decreasing trends in unit WF across all crop groups. However, these reductions are insufficient to curb the increase in total water consumption, which is mostly driven by the growing demand for oil crops. The WF dynamics vary among regions due to a combination of multiple environmental and socio-economic factors. Thus, it is possible to identify key challenges and opportunities in WFs of crop production. Addressing them may benefit water and food security while making the global food system more sustainable.

How to cite: Mialyk, O., Booij, M. J., Hogeboom, R. J., and Berger, M.: Key trends and opportunities in water footprints of crop production, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1556, https://doi.org/10.5194/egusphere-egu23-1556, 2023.

EGU23-2393 | ECS | Orals | ERE1.8

Efficiency of dietary sustainability and its global transition 

Pan He, Zhu Liu, Klaus Hubacek, Giovanni Baiocchi, and Dabo Guan

Global diets consume tremendous natural resources while causing multiple environmental and health issues. As the world faces challenges of adequate nutrition security with concomitant climate and environmental crises requiring urgent action, policies need to improve the efficiency of devoting environmental input of the food systems for health benefits. Here we evaluate the global transition of such efficiency in the past two decades represented by health benefits obtained by per unit of 4 key environmental inputs (GHG emissions, stress-weighted water withdrawal, acidifying emissions, and eutrophying emissions) in 195 countries. We find that the efficiency of each environmental input follows an N-shaped curve along the Socio-Demographic Index (SDI) gradient representing different development levels. The efficiency first increases by benefiting from the eliminated stunting with a larger abundance of food supply, then decreases driven by climbing environmental impacts from a shift to animal products, and finally starts to slowly grow again as countries shift toward a healthier diet. Our efficiency indicator offers an improved understanding of nutritional transitions in terms of environmental impacts and a useful way to monitor the transition of dietary patterns, set up policy targets, and evaluate the effectiveness of specific interventions.

How to cite: He, P., Liu, Z., Hubacek, K., Baiocchi, G., and Guan, D.: Efficiency of dietary sustainability and its global transition, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2393, https://doi.org/10.5194/egusphere-egu23-2393, 2023.

EGU23-3940 | ECS | Orals | ERE1.8 | Highlight

Sustainability trade-offs for equity and climate interventions in global food systems: The case of cocoa in Ghana 

Sophia Carodenuto and Marshall Adams

Despite widespread attempts to ‘eat local,’ many of the lifestyle factors in the Global North rely on the production of agrifood commodities that can only be grown in tropical ecosystems, far from the dominant geographies of consumption. Chocolate, coffee, and palm oil represent a handful of consumer goods that are described as ‘tropical forest risk commodities,’  whose production threatens some of the last remaining biodiversity hotspots and stable carbon sinks. This research assesses the trade-offs between dominant approaches to poverty reduction in tropical forest landscapes – regions where global land use change is concentrated as forests are converted to agrifood commodity production areas to produce consumer goods that are core to global food systems. After Côte d’Ivoire, Ghana is the second largest exporter of cocoa (the main ingredient in chocolate). Ghana’s economy is highly cocoa-dependent, and cocoa provides livelihoods for about a quarter of the population, especially in rural areas where alternative incomes are limited. Although the cocoa sector contributed an estimated US$2.71 billion in government revenues in 2017, many cocoa producers live below the national poverty line.

Policy responses to balance the trade-offs between global food production, climate change, and socioeconomic development have recently come to the fore in Ghana – the world’s second largest producer of cocoa. In 2019, the Government of Ghana introduced the Living Income Differential (LID), which requires buyers to pay an additional US$400 per ton of cocoa on top of the floor price. With low farmer incomes identified as a critical driver of multiple sustainability issues in Ghana’s cocoa sector, this differential is meant to be directly transferred to cocoa farmers in response to the persistent challenge of poverty in cocoa farming communities. Using the Q methodology, we engaged over 50 stakeholders from various levels (international policy experts, cocoa sector stakeholders in Ghana, and cocoa farmers) to understand how LID is perceived, including its potential to transform the rural poverty complex embedded in Ghana’s cocoa supply chain. While the LID is lauded for increasing producer price across the board, our findings indicate that the lack of regard for farmer diversity (i.e., tenure rights, sharecroppers, and caretakers), farm size, and land management strategies (agroforestry versus clearing forest to establish farms) risks undermining the ability of this pricing mechanism to reduce farmer poverty as a way to foster sustainability in the sector. Further, the LID is siloed from on-going sustainability governance efforts in the sector, such as zero deforestation cocoa. If the LID is delivered to farmers across the board without any quid pro quo for how cocoa is produced, the policy’s unintended consequences may include increasing deforestation in the short term, while lowering the world market price of cocoa in the long term as cocoa supply increases. We conclude with policy implications on why different perspectives matter in managing sustainability trade-offs in deforestation frontiers. This study provides important insights for understanding how to achieve multiple sustainability goals together.

How to cite: Carodenuto, S. and Adams, M.: Sustainability trade-offs for equity and climate interventions in global food systems: The case of cocoa in Ghana, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3940, https://doi.org/10.5194/egusphere-egu23-3940, 2023.

EGU23-4584 | ECS | Posters on site | ERE1.8

Enhanced excreta-based biochar: a novel source of organic fertilizer in the Guatemalan highlands 

Benjamin Wilde, Mona Mijthab, Raluca Anisie, Federico La Blasca, Estefani Gonzalez, and Johan Six

Communities in the highlands of Guatemala are currently struggling with insufficient access to effective sanitation. Water born solutions, often referred to as the “flush and forget model” of human excreta management, cannot be adequately delivered to the rapidly growing peri-urban regions growing across the area. The consequences of the insufficient collection and treatment of this waste are worsening human and environmental health outcomes. Concurrently, smallholder farmers in the region struggle to supply their soil with sufficient quantities of plant nutrients to avoid growing yield gaps. Even when capable of utilizing required amounts of chemical fertilizers, there is no clear option available to maintain soil organic carbon; typically relied upon organic inputs such as animal manure are available in only insufficient quantities.

To deal with the sanitation challenge facing communities in the region, Mosan, an NGO based in the Lake Atitlan region of Guatemala has, for the last several years, piloted a novel approach to sanitation provision. Utilizing an on-site urine diversion system that focuses on the capture, processing, and valorization of excreta, this resource-oriented approach, in addition to providing households with the means to safely manage generated excreta, yields a novel organic fertilizer. Using two treatment processes, alkaline dehydration for urine and pyrolysis for the feces, Mosan can produce an enhanced biochar product that could have the potential to sustainably improve soil health and fertility for small holder highland farmers in the region. Working in partnership with Mosan and Vivamos Mejor, and agricultural development organization based in Guatemala, the Sustainable Agroecosystems group at ETH Zurich has been testing the potential of this novel source of organic fertilizer.

Over the last eighteen months, this interdisciplinary team of researchers, community activists, and farmers has managed two experimental sites in the region. The first focused on the incorporation of enhanced biochar into a potting mix used to grow tree seedlings used for reforestation efforts in the region. The second, a participatory farmer field trial, was designed to compare the yield increases of maize fertilized with enhanced biochar to that grown with chemical fertilizer (urea). In addition to observing no significant differences in the growth performance of the seedlings, or the yield increases of the maize grown with the excreta-based biochar compared to the standard alternatives, our team also observed positive changes to several soil physical and chemical properties in the field trial. Given these results, we argue that a socio-technical transition towards a circular rural-urban system, one predicated on nutrient capture and reuse of currently underutilized organic waste sources such as human excreta, would simultaneously improve human and environmental health outcomes in urban areas, while also increasing long term soil health and fertility in outlying rural ones.

How to cite: Wilde, B., Mijthab, M., Anisie, R., La Blasca, F., Gonzalez, E., and Six, J.: Enhanced excreta-based biochar: a novel source of organic fertilizer in the Guatemalan highlands, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4584, https://doi.org/10.5194/egusphere-egu23-4584, 2023.

EGU23-5975 | ECS | Orals | ERE1.8

Restructuring the Indian agricultural system toward sustainability and lower environmental costs 

Udit Bhatia, Shekhar Goyal, and Rohini Kumar

The evolving international conflicts have a rippling effect on global food security, forcing nations to impose new trade laws to increase their domestic supply at reduced prices and promote the need to develop local and regional food systems to reduce transboundary dependence. While aiming to become a major global food supplier, India faces significant domestic food security risks. India has achieved food security through injudicious fertilizer application on the domestic front. Past agricultural policies, while primarily focusing on maximizing production, paid less attention to their environmental consequences. India feeds 17.1% of the world's population, with 10.7% of the world's arable land: this will further increase with increasing national and international food trade. Sustainably feeding the growing population has garnered considerable attention; however, its national implementation still needs to be improved. The current intensive agricultural practices operate at low water, nutrient, and nutritional efficiencies, demanding high input for high output. As a result, Nitrogen, Phosphorus losses are high, and groundwater resources are depleting in some areas. The vexing question is how to produce sufficient food in the existing regions with minimum inputs and reduced environmental impact. For this, India must reconfigure its current cereal crop production and interstate crop distribution system by reducing nutrient pollution losses, greenhouse gas emissions, and water consumption while sufficing its increasing nutritional demand. Using a state-of-the-art framework from agricultural sciences, network, and resource optimization, our study provided ways toward national assessment of Indian staple crop system redesign for future sustainable intensification.  Further, by incorporating interstate trade within this restructured system, we try to understand how India's cereal crop redistribution will impact domestic food security. Thus to limit the environmental burden of the growing consumer demand, we optimized crop distribution and domestic trade patterns within the parameters of minimizing nitrogen and phosphorus losses. This realistic multi-dimensional framework will help India and other nations identify sustainable food security solutions. 

How to cite: Bhatia, U., Goyal, S., and Kumar, R.: Restructuring the Indian agricultural system toward sustainability and lower environmental costs, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5975, https://doi.org/10.5194/egusphere-egu23-5975, 2023.

EGU23-6115 | ECS | Posters on site | ERE1.8

Climate change alters the global diversity of food crops 

Sara Heikonen, Matias Heino, Mika Jalava, and Matti Kummu

Climate change has already impacted the productivity of important food crops. The projected increasing temperatures and changing precipitation patterns affect the climatic suitability of food production areas. Changes in climatic suitability require adaptive actions on farms and will likely alter the potential volume and diversity of food crop production globally.

Existing research has mostly analysed the impacts of climate change on the four staple crops: wheat, rice, maize, and soybean. However, other food crops contribute more than 50% to the global calorie and protein supply and therefore constitute a crucial element of food security. Moreover, these crops might succeed in more diverse climate conditions than the staple crops. If climate change narrows the production potential of the staple food crops, other food crops could become even more important for global food security in the future. Therefore, to comprehensively understand the implications of climate change on food crop production, there is need for analysis on a diverse set of food crops.

In this study, we delineate suitable climate conditions for 27 major food crops using historical climatic data and examine the effect of future changes in climate suitability on food crop production volume and diversity. We define the crop-specific suitable climate conditions utilizing the Safe Climatic Space concept, based on global gridded datasets on biotemperature, precipitation, and aridity in 1970–2000 as well as crop production in 2010. Then, using future climate parameter data, we project changes in global climate suitability for the 27 food crops. The analyses cover five global warming scenarios from +1.5 °C to +5 °C.

The preliminary results indicate that the global food crop production potential on the current croplands will decrease for most crops in all five global warming scenarios. Furthermore, the potential diversity of food crops will decrease significantly at low latitudes but increase in other areas. In all five scenarios, areas near the equator will become unsuitable for most studied crops. On the other hand, on the current extent of cropland, the potential production area of especially oil crops and starchy roots will expand in the northern hemisphere.

For many crops, there is distinct difference in the magnitude of lost production and diversity potential between global warming of +2 °C and +3 °C, highlighting that it is important to restrict global warming at the very maximum to +2 °C. The results of this study could provide insights for agricultural adaptation to climate change by illustrating opportunities for geographically shifting or expanding production in regions where climate suitability is projected to change. Further, the results could identify potential substitute crops for regions where climate conditions might become unsuitable for the currently cultivated food crops.

How to cite: Heikonen, S., Heino, M., Jalava, M., and Kummu, M.: Climate change alters the global diversity of food crops, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6115, https://doi.org/10.5194/egusphere-egu23-6115, 2023.

EGU23-6434 | Orals | ERE1.8

Energy and fertiliser price rises are more damaging than food export curtailment from Ukraine and Russia for food prices, health and the environment 

Peter Alexander, Almut Arneth, Roslyn Henry, Juliette Maire, Sam Rabin, and Mark Rounsevell

Higher food prices arising from restrictions on exports from Russia or Ukraine have been exacerbated by energy price rises, leading to higher costs for agricultural inputs such as fertiliser. Using a scenario approach with a global land use and food system model (LandSyMM), we quantify the potential outcomes of increasing agricultural input costs and the curtailment of exports from Russia and Ukraine on human health and the environment.  We show that, combined, agricultural inputs costs and food export restrictions could increase food costs by 60-100% from 2021 levels, potentially leading to undernourishment of 60-110 million people and annual additional deaths of 400 thousand to 1 million people if the associated dietary patterns are maintained. In additional to lower yields, reduced land use intensification arising from higher input costs would lead to agricultural land expansion of 130-349 Mha by 2030, with associated carbon and biodiversity loss. The impact of agricultural input costs on food prices is larger than that from curtailment of Russian and Ukrainian exports. Restoring food trade from Ukraine and Russia alone is therefore insufficient to avoid food insecurity problem from higher energy and fertiliser prices. While the Black Sea Grain Initiative has been a welcome development and has largely allowed Ukraine food exports to be re-established, the immediacy of these issues appears to have diverted attention away from the impacts of fertiliser prices. While fertiliser prices at the start of 2023 have come down from the peaks of mid-2022, they remain at historically high levels.  Our results suggest the costs and lower crop yields achieved through reduced fertiliser use will drive high food price inflation in 2023 and beyond. More needs to be done to break the link between higher food prices and harm to human health and the environment.  

This study demonstrates how modelling can be used to explore the complexity and interlinked nature of the globalised food system and to quantifying the trade-offs and synergies for health and environmental outcomes of difference scenarios.

How to cite: Alexander, P., Arneth, A., Henry, R., Maire, J., Rabin, S., and Rounsevell, M.: Energy and fertiliser price rises are more damaging than food export curtailment from Ukraine and Russia for food prices, health and the environment, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6434, https://doi.org/10.5194/egusphere-egu23-6434, 2023.

Extreme weather often causes crop losses with sharp fluctuations in agricultural prices, which imposes negative impacts on sustainable agricultural development. Greenhouse farming is regarded as an effective measure against extreme weather. Thus, it requires a better understanding of the growing complexity of agri-food systems involving greenhouse environmental and societal tradeoffs under climate variations. Considering high energy consumption of greenhouses, this study aims at adopting machine learning with IoT-big data mining to innovatively develop a smart greenhouse environmental control service model under the nexus between meteorology, water, energy, food, and greenhouse environmental control while exploring pathways to low-carbon greenhouse cultivation. The proposed model will be applied to greenhouses in Taiwan for evaluating cross-sectoral synergies and environmental benefits. The results are expected to support greenhouse owners and authorities to make the best use of resources of water, energy, and food through the optimal environmental operation on greenhouse cultivation under extreme climatic events for achieving sustainable development goals (SDGs) and move towards green economy.

How to cite: Hsia, I.-W. and Chang, F.-J.: Machine Learning-Enabled Smart Greenhouse Environmental Control Service Model, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6494, https://doi.org/10.5194/egusphere-egu23-6494, 2023.

Agriculture is a key to the Zambian economy, contributing 20% to the country’s GDP and 12% to the national export earnings. However, climate change has a negative impact on Zambian agriculture production. In line with its Vision 2030 to have an efficient, competitive, sustainable and export-led agriculture sector, Zambia is aiming to improve irrigated agriculture through large investment in irrigation. Considering climate change and variability, it is important to adopt best water and nutrient management practices for sustainable use of agricultural resources. Maize being the major staple crop of Zambia, a study was carried out to improve irrigation management by optimizing water and nitrogen use efficiency for maximum maize productivity at field level under varying water and fertilizer applications. To achieve this goal, our study used and adapted nuclear (neutron probe) and isotope (15N and 13C) techniques to the Zambian agro-ecological conditions. Drip irrigation was used as the targeted system. The experiment was implemented based on three water application levels, i.e., deficit (50% and 75% Evapotranspiration) versus optimal (100% Evapotranspiration)and three nitrogen (N) levels (140 kg.ha-1, 112 kg.ha-1 and 84 kg.ha-1, widely practiced being 112 kg.ha-1). Maize was grown as a sole crop, under drip irrigation, in rotation with a legume over the dry season of Zambia in 2021 and 2022. For both years, maize yield was ranging between 2 and 7 ton.ha-1. Results showed that deficit irrigation can be practiced without a significant negative impact on yield (with higher N levels showing significantly higher yields under deficit irrigation) and nitrogen use efficiency. The total N yield and agronomic water use efficiency were significantly higher, up to 1.5 and 3 times respectively, under deficit irrigation as compared to the optimal. Intrinsic water stress (d 13C results) was higher, though not statistically significant, under deficit irrigation. Thus, considering climate change and sustainable use of resources, deficit irrigation should be considered as the option to achieve higher yield and food security.

How to cite: Mwape, M., Said, H., Phiri, E., Heiling, M., Dercon, G., and Resch, C.: Understanding the interaction between maize water use efficiency and nutrient uptake in irrigated cropping systems, a basis for predicting and improving Zambia’s productivity in a changing climate, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6729, https://doi.org/10.5194/egusphere-egu23-6729, 2023.

EGU23-7963 * | ECS | Orals | ERE1.8 | Highlight

Healthier diets, healthier planet? Quantifying the biodiversity pressure of fruit and vegetable consumption in South Africa, India, and the UK 

Abbie Chapman, Carole Dalin, Sara Bonetti, Rosemary Green, Genevieve Hadida, Tafadzwa Mabhaudhi, and Pauline Scheelbeek

Eating more fruits and vegetables lowers risk of non-communicable diseases. Globally, people are not eating the recommended amounts of these foods; consumption must increase to improve human health. However, in general, areas of cropland are associated with lower biodiversity than natural land (e.g., forests and grasslands). Converting natural land to cropland for agriculture therefore risks biodiversity loss which, in turn, risks lowering crop yields because biodiversity supports food production via pollination and pest control. Herein lies a trade-off. As the world seeks to eat more healthily, more fruits and vegetables will be produced to meet demand. Here, we share our research into this trade-off between healthy diets and biodiversity conservation.

To quantify the biodiversity pressure associated with healthy fruit and vegetable crops, we made use of freely available data on: species distributions (IUCN, 2013); fruit and vegetable production, yield, and harvested area (Monfreda et al., 2008); and international trade of fruits and vegetables (FAOSTAT; Dalin et al., 2017). Previous research into cropland-biodiversity relationships has typically grouped land-cover types into ‘cropland’ and ‘natural land’, without considering the impacts of specific crops on biodiversity (except for major commodities, like cocoa, and staples, like maize). We have developed a new suite of biodiversity-pressure metrics for specific crops which can be measured globally. These metrics enable us to quantify the species potentially impacted for each unit of crop in both a consumer country and its trade-partner countries. The new measures facilitate quantitative comparisons among specific crops and countries for the first time. Using these new measures, we compared the biodiversity pressures associated with the production and consumption of 54 different fruits and vegetables. We mapped the origin of crops consumed in the UK, South Africa, and India, and quantified associated biodiversity pressures relative to food produced and imported.

Contrary to previous research considering the relative impacts of food crops on climate change and water resources, biodiversity pressure due to fruit production is not always higher than that due to vegetables. The most important factors associated with increased biodiversity pressures include the country of production and the amounts being produced. We did not identify a single suite of crops standing out as particularly unsustainable across all three focal countries. This is significant, as it emphasizes the importance of trade in influencing sustainability. For some crops, domestic production would have a lower biodiversity pressure than importing from trade partners (e.g., UK-grown tomatoes). In such cases, the domestic production of fruits and vegetables should be promoted in conjunction with biodiversity-friendly farming practices. In other cases, domestic production of a crop is associated with a higher biodiversity pressure than the crop’s biodiversity pressure when produced overseas (e.g., UK-grown cherries). Our findings are particularly important in the context of changing trade patterns since the early 2000s, where countries like the UK have been increasingly sourcing fruits and vegetables from abroad. Our results could therefore inform policies aimed at tracing the environmental impacts of food-supply chains in the UK, India, and South Africa.

How to cite: Chapman, A., Dalin, C., Bonetti, S., Green, R., Hadida, G., Mabhaudhi, T., and Scheelbeek, P.: Healthier diets, healthier planet? Quantifying the biodiversity pressure of fruit and vegetable consumption in South Africa, India, and the UK, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7963, https://doi.org/10.5194/egusphere-egu23-7963, 2023.

EGU23-10063 | Orals | ERE1.8

Risk of deforestation and potential greenhouse gas emissions from vegetable oils’ expansions for food use 

Maria Vincenza Chiriacò, Nikolas Galli, Monia Santini, and Maria Cristina Rulli

The global production of vegetable oils exceeds 200 million tonnes per year, with almost 40% for food use, and around 330 M hectares occupied by oil crops. The most produced is palm (40% if palm kernel oil is included), followed by soybean oil (28%), rapeseed oil (12%) and sunflower oil (9%). Some of these oil crops, particularly oil palm plantations and soy cultivations, are among the main drivers of global land use changes (LUC) and deforestation. In particular palm oil has been one of the most highly criticized due to the link between oil palm cultivation expansion and the loss of primary tropical forests, observed in recent decades. This issue has generated two different responses in the food sector: some players decided to produce and/or use deforestation-free palm oil. Other actors chosen to replace palm oil with other vegetable oils, such as soybean, rapeseed and sunflower oil.

Considering the importance of a proper land management in view of the food-ecosystems-resources nexus, this study assesses the potential LUC and the related GHG emissions that can occur by using sustainable palm oil or replacing it with the other oils for food use. 

A methodology was developed to assess the potential GHG emissions from the LUC due to alternative oil crops expansion at detrimental of high carbon content areas, such as forests or perennial croplands, and the GHG emissions from the production process though a Life Cycle Assessment (LCA).

Under the scenario of 100% replacement of palm and palm kernel oil globally, the extra-land needed to produce the additional alternative oils was determined in their three top producer countries using yield data from literature. An expansion algorithm considering suitability and distance from roads and existing oil crops was developed to determine the potential LUC which may occur in the selected countries. The potential GHG emissions from deforestation and other LUC were calculated from the carbon stock data of the FAO Forest Resource Assessment and IPCC; the field production of the four oils was reconstructed to calculate anthropogenic GHG emissions using relevant LCA existing databases. 

Results show that deforestation-free palm oil is the less impacting in terms of GHG emissions per oil ton thanks to its far highest oil yield. Replacing sustainable palm oil with any other alternative oil is never a favourable solution (Fig. 1), entailing a potential GHG emissions increase from 0.94-0.96 Mg CO2  per ton of palm oil replaced by sunflower oil produced in Ukraine or in Russia (where deforestation is unlikely), to 4.38 Mg CO2 per ton of palm oil replaced by soybean oil produced in Brazil, up to 13.65 Mg CO2 per ton of palm oil replaced by soybean oil produced in Argentina.

 

Figure 1. GHG emissions in Mg CO2eq t-1 from LCA (blue bars) and LUC (green bars) with 100% palm oil replacement. Based on national trends and forest policies, potential deforestation can be likely (full green), likely with limitation (dense dots), likely with offset (oblique lines), unlikely (scattered dots). Vertical lines for palm oil include deforestation.

 

How to cite: Chiriacò, M. V., Galli, N., Santini, M., and Rulli, M. C.: Risk of deforestation and potential greenhouse gas emissions from vegetable oils’ expansions for food use, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10063, https://doi.org/10.5194/egusphere-egu23-10063, 2023.

EGU23-11242 | ECS | Posters on site | ERE1.8

Effect of urease inhibitor and biofertilizer on nitrous oxide emission 

Rayehe Mirkhani, Christian Resch, Georg Weltin, Lee Kheng Heng, Jason Mitchell, Rebecca Clare Hood-Nowotny, and Gerd Dercon

Conventional agricultural practices are heavily dependent on nitrogen fertilizers, which can have negative impacts on the environment through ammonia volatilization and nitrous oxide emission. Previous studies have shown that the use of urease inhibitors or biofertilizers may help reduce such impacts.

A field experiment was established by the Joint FAO/IAEA Centre at the experimental station of the University of Natural Resources and Life Sciences (BOKU) located east of Vienna (Austria) to determine the effect of urease inhibitor and biofertilizer on nitrous oxide (N2O) emission, in wheat cropping systems. A randomized complete block design including five treatments and four replicates was used in this study. The treatments were: T1 (control treatment - without N fertilizer), T2 (Urea only), T3 (Urea+Urease Inhibitor (UI)), T4 (Urea+Biofertilizer), T5 (Urea+UI+Biofertilizer). All treatments received 50 kg N ha-1 at tillering stage (GS 31), except T1. In this study N-(n-butyl) thiophosphoric triamide (nBTPT) or “Agrotain” was used as UI and Azotobacter chroococcum (“AZOTOHELP”) was applied as biofertilizer.

Soil N2O gas fluxes were measured using the static chamber method, eight times between 3 to 84 days after fertilizer application. Gas sampling was performed at the same time each day of measurement, between 8:00 and 10:00 h, to minimize diurnal variation and better represent the mean daily fluxes. A PVC chamber (24 cm height and 24 cm diameter) was inserted into the soil 5 cm deep. The chamber was composed of two separate parts joined together with an airtight rubber. Gas samples were taken at 0 and 30 minutes after closing the chambers using a 500 mL syringe. The gas sample was then immediately transferred from the syringe to a pre-evacuated 1L gas sampling bag with multi-layer foil. Nitrous oxide in the gas samples was analysed using off-axis integrated cavity output spectroscopy (ICOS, Los Gatos).

The statistical analysis showed that UI and biofertilizer had a clear and significant effect on nitrous oxide emission. However, this effect was only observed during the first week after the fertilizer application. Further, the results showed that the highest N2O emission, within this week after adding urea fertilizer, was under the U+UI treatment, which was significantly higher by about 139, 91,79% compared to the Urea+Biofertilizer, Urea, Urea+UI+Biofertilizer treatments, respectively. No significant difference was observed between the other Urea, Urea+Biofertilizer and Urea+UI+Biofertilizer treatments in this period. Although not significantly (p < 0.05), N2O emission was higher in Urea+UI+Biofertilizer treatment compared to the Urea+Biofertilizer treatment.

Due to the ability of UI to reduce ammonia volatilization, we assume that pollution swapping from ammonia volatilization to nitrous oxide emission occurred, explaining the stimulus of UI on nitrous oxide emission. The lower N2O emission in the treatments receiving biofertilizer, compared to the one with no biofertilizer, may be caused by the ability of Azotobacter to reduce N2O emission by N2O-fixation, N2 fixation and reduction of N2O to N2.  

How to cite: Mirkhani, R., Resch, C., Weltin, G., Heng, L. K., Mitchell, J., Clare Hood-Nowotny, R., and Dercon, G.: Effect of urease inhibitor and biofertilizer on nitrous oxide emission, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11242, https://doi.org/10.5194/egusphere-egu23-11242, 2023.

EGU23-11440 | ECS | Orals | ERE1.8

The potential to increase resilience by replacing feed imports with domestic food system by-products 

Vilma Sandström, Matti Kummu, and Florian Schwarzmueller

Many of the key feedstuff, such as oilseed meals or fishmeal, used in livestock and aquaculture production are highly traded commodities in global agricultural markets. The dependence on these imported inputs creates vulnerabilities to the production countries when disturbances on global trade flows occur. Increasing the feed use of the available food system by-products offers a solution to decrease the dependency and increase food system circularity and resilience. In this global study we combine trade data from various sources of the material flows in feed trade and estimate for the first time the potential to replace the imported feeds with a more efficient use of food system by-products from domestic production. The results highlight the materials and areas with most potential to guide and inform decisions when looking for solutions in the transition towards more sustainable food systems.

How to cite: Sandström, V., Kummu, M., and Schwarzmueller, F.: The potential to increase resilience by replacing feed imports with domestic food system by-products, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11440, https://doi.org/10.5194/egusphere-egu23-11440, 2023.

EGU23-12259 | ECS | Posters on site | ERE1.8

Effect of urease inhibitor and biofertilizer on wheat yield and related crop parameters 

Corinna Eichinger, Rayehe Mirkhani, Lee Kheng Heng, Jason Mitchell, Rebecca Clare Hood-Nowotny, and Gerd Dercon

Agricultural production must increase by 50% to support about 9 billion people by 2050. Previous studies show that integrated crop-soil management strategies can improve cereal yield by 30% without increasing nitrogen use. Sustainable practices and the application of environmentally friendly technologies can help to reach this point by improving resource use efficiency and increasing yield. For this purpose, the effect of urease inhibitor and biofertilizer were evaluated in this study as environmentally friendly technologies that can increase cereal grain yield.

In the spring of 2022, a field experiment was established at the experimental station of the University of Natural Resources and Life Sciences (BOKU), located in the east of Vienna, to determine the effect of urease inhibitor and biofertilizer on wheat production. A randomized complete block design including five treatments and four replicates was used in this study. Each main plot was 9 by 9 meters, and a buffer zone of 1.5 meters was implemented between each of the individual main plots. The treatments were: T1 (control treatment - without N fertilizer), T2 (Urea only), T3 (Urea+Urease Inhibitor (UI)), T4 (Urea+Biofertilizer), T5 (Urea+UI+Biofertilizer). All treatments received 50 kg N ha-1 at tillering stage (GS 31), except T1. In this study N-(n-butyl) thiophosphoric triamide (nBTPT) or “Agrotain” was used as UI and Azotobacter chroococcum or “AZOTOHELP” was applied as biofertilizer. To determine wheat yield (grain and straw), a 1.5 by 8 meter area was harvested in each main plot (9 by 9 meters). To measure other parameters including the number of tillers per square meter, 1000-grain weight (g), plant height (cm), spike length (cm) and numbers of grains per spike, a 1m-by-1m area was harvested within each main plot for all treatments.

The highest grain and straw yields were observed in the Urea+UI+Biofertilizer treatment, with a grain yield of about 20, 11, 8% higher, compared to the Urea, Urea+UI and Urea+Biofertilizer treatments, respectively. However, a significant difference in grain and straw yields was only observed between Urea and Urea+UI+Biofertilizer treatments. The grain and straw yields in the Urea+UI and Urea+Biofertilizer treatments were not significantly different from both Urea and Urea+UI+Biofertilizer treatments. The number of grains per spike and the weight of 1000-grain in the Urea+UI+Biofertilizer treatment showed an increase of about 20 and 11% respectively, compared to the Urea treatment, but these increases were not significant. Plant height in treatments that received nitrogen fertilizer was not affected by fertilization treatments, but spike length was affected. This study suggests that the use of urea fertilizer coated with urease inhibitor in combination with biofertilizer is a promising way for sustainable crop production in the lowlands of Austria.

How to cite: Eichinger, C., Mirkhani, R., Kheng Heng, L., Mitchell, J., Hood-Nowotny, R. C., and Dercon, G.: Effect of urease inhibitor and biofertilizer on wheat yield and related crop parameters, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12259, https://doi.org/10.5194/egusphere-egu23-12259, 2023.

EGU23-12478 | ECS | Orals | ERE1.8

Tracing the water footprint of food losses the in trade network: the case of wheat 

Francesco Semeria, Francesco Laio, Luca Ridolfi, and Marta Tuninetti

Food loss and waste is increasingly becoming a topic of great public concern: in 2011, FAO presented the estimate that around one third of the world’s food was lost or wasted every year and SDG 12 (“Sustainable consumption and production”) from Agenda 2030 includes among its targets to “halve per capita global food waste” and to “reduce food losses”. The impact on environmental resources is significant: in particular, 24% of total freshwater resources used in food crop production are lost in the different stages of food loss and waste. While in high-income countries food is mainly wasted at the consumer level, low-income ones record losses concentrated in the agricultural and post-harvest stages. Globally, food markets are telecoupled and globalized, so wasted food has effects on water resources in the whole supply chain, propagating along the trade network up to the countries of initial production, where water resources have been utilized, often through irrigation, altering the local hydrological cycle. The reconstruction of such network is one of the most challenging aspects of tracing the impact of food waste on water resources. The difficulties are due to the numerous food re-exports and nested supply chains, to the different origins of food waste (from production to distribution and consumption), and to the marked variability of the country-specific unit water footprints. As a key hypothesis, we assumed that in each country the ratio between imports and domestic production would be the same in both domestic consumption and exports, to cope with re-export feedbacks in the network. Focusing on the emblematic case of wheat and its derivatives (e.g., flour, bread, pasta), we were able to reconstruct the complex global network that connects losses and wastes at any stage along the supply chain with the corresponding wasted water resources.

Our results show that, for most countries, the network is very extensive and involves many states around the world. For example, in 2016 over 20 foreign countries employed their water resources to produce wheat which in turn was wasted as bread in Italy at the consumer level, accounting for around 15% of the bread’s water footprint (870 m3/t).  This highlights how much water resources are now globalized and that the waste of food in a country can impact even very distant water resources. We also quantify the contribution of each waste component, from agriculture’s field losses to consumers’ household wastes. For Italy, 54% of losses related to bread are at the consumption stage, while only 6% occur at the agricultural stage. Eventually, we present how the relative importance of each component varies, depending on the network of countries involved in the production, storing, processing, distribution and consumption of food.

How to cite: Semeria, F., Laio, F., Ridolfi, L., and Tuninetti, M.: Tracing the water footprint of food losses the in trade network: the case of wheat, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12478, https://doi.org/10.5194/egusphere-egu23-12478, 2023.

EGU23-12940 | Posters on site | ERE1.8

An evaluation of smartphone applications for LAI estimation to facilitate canopy state assessment in vineyards 

Georgios Ovakoglou, Ioannis Navrozidis, Vasileios Pyrgiotis, Nikos Kalatzis, and Thomas Alexandridis

Crop development and foliar density as expressed with Leaf Area Index (LAI) is an important source of information for disease prevention. Canopy density in vineyards has been correlated with disease incidence, mainly concerning the impact of high density on intra-canopy ventilation and levels of humidity. LAI data can be used together with other data sources, such as temperature, humidity, rainfall etc., to enhance disease predictive models and continuous monitoring of crops. To improve the crowdsourcing aspect of data collection from farmers and agronomists capturing in-field observations, this study was implemented aiming to evaluate LAI smartphone applications. The applications selected for testing and evaluation were smart fLAIr (https://sys.cs.uos.de/smartflair) and VitiCanopy (https://viticanopy.com.au), selected based on their applicability, subscription pricing, user-friendliness and continued support from the developers among all available Android applications. The smartphone applications were evaluated against LiCOR 2200C plant canopy analyzer (https://www.licor.com/env/products/leaf_area/LAI-2200C) to demonstrate the measurement accuracy of each. Sampling for this experiment was carried out in four plots (25 points/plot, 100 total) applying gaiasense smart farming services (https://www.gaiasense.gr/en/gaiasense-smart-farming), located in two irrigated commercial vineyards in Stimagka, southern Greece. The collected samples were representing various canopy states considering foliar density. Sampling took place during early morning hours (after sunrise) for the first two plots, while the remaining two plots were sampled after midday to early afternoon hours (before sunset). All sampling locations were recorded with geo-tagged photographs. A cap-view of 45o under clear-sky conditions was used for LiCOR2200C measurements and atmospheric scattering correction was applied, following a 4A measurement sequence protocol as described in the instruction manual (https://licor.app.boxenterprise.net/s/fqjn5mlu8c1a7zir5qel). FV2200 software (https://www.licor.com/env/support/LAI-2200C/software.html) was used to process the LiCOR dataset. Statistical analyses were performed after excluding 10% of total acquired samples as outliers. The results show that VitiCanopy has greater accuracy compared to fLAIr with a correlation coefficient of 0.65 over 0.25, while producing overestimated LAI values (mean diff = 0.74, p<0.0001). On contrast, fLAIr generated slightly underestimated LAI values (mean diff=-0.24, F=0.0155). Per plot analysis showed that measurements acquired earlier during the day (first two plots) provided higher correlation values (0.39<r<0.64), while those acquired after midday scored lower (r<0.12). This comes in agreement with relevant literature, suggesting that the ideal light conditions for accurate LAI measurements (under clear-sky conditions) is the earliest possible after sunrise. Although correlation values remained low to moderate (0.07<r<0.64), findings indicate that VitiCanopy performs more accurately than fLAIr and can be used as an alternative to costly and sophisticated equipment, however caution should be taken while standardising the optimal atmospheric/lighting conditions. This insight can be useful for disease predictive models, as well as farmers and agronomists who seek an accessible way to monitor LAI, potentially leading to spatially variable spraying applications. Future plans include the integration of LAI measurements as an additional parameter within the gaiasense’s Smart Farming solution aiming to enhance information richness of the existing operational pest infestation risk index calculation algorithms for vineyards.

This work was supported by EU-H2020 project ‘Resilient farming by adaptive microclimate management’ (STARGATE – 818187).

How to cite: Ovakoglou, G., Navrozidis, I., Pyrgiotis, V., Kalatzis, N., and Alexandridis, T.: An evaluation of smartphone applications for LAI estimation to facilitate canopy state assessment in vineyards, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12940, https://doi.org/10.5194/egusphere-egu23-12940, 2023.

EGU23-15016 | Orals | ERE1.8

A novel tool implementation to estimate the Land Use Sustainability for crops production under different climate change scenarios 

Joan Miquel Galve, Jesús Garrido-Rubio, José González-Piqueras, Anna Osann, Alfonso Calera, Maria Llanos López, Esteban Henao, David Sánchez, Jesús Puchades, Antonio Jesús Molina, Christina Papadaskalopoulou, Marina Antoniadou, and Dimitris Tassopoulos

The sustainability of crop production regarding different climate change scenarios will compromise actors and activities involved in agri-food systems. Furthermore, sustainable development was defined by the World Commission on Environment and Development as the ability to meet present demands without compromising the needs of future generations. In parallel, according to the Food and Agriculture Organization (FAO), land evaluation is the process of projecting land use potential based on its characteristics, and it has been the principal approach used worldwide to manage land use planning. Its use today is required due to changing needs and pressures from decision-making policies or agricultural market tendencies among others, so a rational use of natural land is a crucial goal for economic development. However, future climate change scenarios will modify the actual crop development conditions and must be tackled.

This paper presents two case studies at the river basin scale to determine the Land Use Suitability (LUS) analysis that is performed according to the FAO framework, thus, areas that are the most suitable for crops using GIS and multicriteria methodology that involves actual and future climatic conditions under different climate change scenarios, crop management practices and edaphological conditions for different crops. The tool developed generates a product that classifies areas suitable for a particular crop from a collection of maps and their corresponding thresholds. The approach involves standardizing the suitability maps, assigning relative importance weights to the suitability maps, and then combining the weights and the standardized suitability maps to obtain a suitability score.

In this paper, the wheat crop LUS at the Júcar River Basin (42,735 Km2, located in Spain) and the cotton LUS at the Pinios River Basin 11,000 km2, located in Greece) are evaluated. Once the LUS is estimated, a collection of yearly thematic maps over both river basins is ready for use by local stakeholders, regarding different climate change scenarios (RCP 4.5 and RCP 8.5).

These results are part of the EU Horizon 2020 project REXUS (Managing Resilient Nexus Systems Through Participatory Systems Dynamics Modelling), in which local stakeholders, from farmers to land use managers, are collecting and evaluating the information. Our final goal is to provide spatial information for future climate change scenarios that increase land-use knowledge and enhance decision-making policies.

How to cite: Galve, J. M., Garrido-Rubio, J., González-Piqueras, J., Osann, A., Calera, A., López, M. L., Henao, E., Sánchez, D., Puchades, J., Molina, A. J., Papadaskalopoulou, C., Antoniadou, M., and Tassopoulos, D.: A novel tool implementation to estimate the Land Use Sustainability for crops production under different climate change scenarios, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15016, https://doi.org/10.5194/egusphere-egu23-15016, 2023.

EGU23-15056 | ECS | Orals | ERE1.8

Usage of by-products and residues of the food system in livestock diets leads to savings in global land and water resources 

Camilla Govoni, Paolo D'Odorico, Luciano Pinotti, and Maria Cristina Rulli

Animal foods play an important role in human nutrition providing essential micro and macronutrients. In addition, animal-source foods cover 16% of the global food supply, so contribute to global food security. However, livestock consumes about 70% of the global agricultural land and one-third of the freshwater available for agriculture, thus fueling the debate on the competition between the food and the feed sector for the use of increasingly scarce natural resources. Several studies suggest that more efficient management in the food system can reduce competition and increase the global food supply without further pressure on resources. Here we propose a strategy consisting in the replacement of energy-rich food-competing feeds, such as cereals and tubers, with agricultural by-products and residues. Thus, we analyze both the current impact on land and water use for animal-source foods and the natural resources (i.e. land and water) saving associated with the replacement. To this aim, we collected data on regional feed use and the potential replacement of these feeds with actually available by-products and residues. Then, the collected data are combined with countries-specific crop yields and a dynamic spatially distributed and physically based agro-hydrological model to analyze the difference in the land and water use between the current baseline condition and the substitution scenario. Considering the replacement of five major cereals and cassava estimated to range between 11% to 16% of their feed use, the potential amount of fertile land and green water volume that could be saved ranges from 10% to 14%, while from 11% to 17% for the blue water volume. While Eastern Asia and North America would reduce their energy-rich feed crop consumption the most, would be Southern, Eastern, and South-Eastern Asia, and Eastern Europe that would benefit the most from the use of agricultural by-products and residues to save land and green water resources. As far as blue water is concerned, the highest savings are expected to occur in Asia, where cereal production is traditionally irrigated, although linked to unsustainable water withdrawals. Furthermore, the effect of trade on the consumption of natural resources, namely virtual land and water trade, is also explored, with feed crop production relocated through virtual resource flows. While Eastern Europe, Northern America, and South America appear as net land and green water exporters, Eastern and Western Asia and Southern Europe appear as net importers, and Western Europe, instead, as both an importer and exporter region through feed trade. On the other hand, Asia and Northern America appear to be net freshwater exporters. As the demand for livestock products grows over the next half-century, any strategy aimed at curbing the demand for primary commodities and making the food system more resilient has the benefit of reducing environmental impacts on both local and distant areas of the world but also the trade dependency of countries, in a time where global food security is threatened by several factors.

How to cite: Govoni, C., D'Odorico, P., Pinotti, L., and Rulli, M. C.: Usage of by-products and residues of the food system in livestock diets leads to savings in global land and water resources, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15056, https://doi.org/10.5194/egusphere-egu23-15056, 2023.

EGU23-15211 | ECS | Posters on site | ERE1.8

SEDIMENT REUSE FROM TROPICAL RESERVOIRS: assessing the suitability of sediment material for soil improvements and impacts of the practice on plant growth 

Braga Brennda, Arlena Bronsinsky, Saskia Foerster, and Pedro Medeiros

Due to the high rainfall variability in the Brazilian semi-arid region and the occurrence of long periods without rain, society has adopted techniques to cope with drought, with focus on the construction of surface reservoirs. However, silting is causing a decrease in the water storage capacity of those structures, reducing their depth, increasing water losses by evaporation and contributing to the degradation of water quality by adsorbed pollutants. In a context where mitigating solutions are necessary, removal of the nutrient-enriched sediment from the reservoirs’ beds and their subsequent reuse for soil fertilization have been proposed. To assess the potential of the sediment as fertilizer, maize plants were grown under controlled conditions in a greenhouse, considering: i) soil from the region where the sediment was collected with no amendments, ii) soil with 100% of the nitrogen recommendation provided by mineral fertilizer (iii) soil with sediment from São Nicolau reservoir (iii), soil with sediment from São Joaquim reservoir (iv). We observed higher relative chlorophyll content, plant growth and biomass production of maize plants from the soil with added sediment, with a similar behavior to plants growing in the soil with chemical fertilizer. We also found that the silt improves soil structure by increasing the water retention capacity of the soil. We have previously evaluated that this technique is economically feasible and can present savings of up to 30% in relation to traditional fertilization, depending on the characteristics of the sediment. However, sediments from the same hydrographic region may present high spatial variability in their physicochemical characteristics. Therefore, it is relevant to map the spatial distribution of the sediment characteristics. Recently, we demonstrated that diffuse reflectance spectroscopy might be useful to characterize sediments at lower costs and efforts than by laboratory analyses: for instance, regression models for electrical conductivity and clay content performed in the range of good to very good in the study region. A further promising approach is the application of spaceborne imaging spectroscopy to estimate the concentration of elements such as sodium, the electrical conductivity, the content of clay and organic matter in the sediment. The derived information can be used for informed decisions in the application of sediment reuse practice. For example, if the electrical conductivity of the sediment is higher than 4 dS/m, addition of sediment to the soil may prevent plant growth and, therefore, its reuse is not recommended. Thereby, sediment reuse can also potentially promote de-silting of reservoirs, reducing the carbon footprint associated with traditional fertilization and improving the water quality of small reservoirs, the main source of water supply for rural families, by removing nutrients that could return to the water column. In addition, the use of sediments may represent an alternative to increase agricultural production, being less susceptible to market price variation than commercial fertilizers. The CAPES/PROBRAL and the Deutscher Akademischer Austauschdienst (DAAD) are acknowledged for the financial support.

How to cite: Brennda, B., Bronsinsky, A., Foerster, S., and Medeiros, P.: SEDIMENT REUSE FROM TROPICAL RESERVOIRS: assessing the suitability of sediment material for soil improvements and impacts of the practice on plant growth, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15211, https://doi.org/10.5194/egusphere-egu23-15211, 2023.

EGU23-15582 | ECS | Orals | ERE1.8

Sustainable agricultural strategies to address limited freshwater availability and meet food demand in the Nile River Basin 

Martina Sardo, Maria Cristina Rulli, and Davide Danilo Chiarelli

Providing healthy food from a sustainable food system, while satisfying the demand of a growing population, is one of the major challenges of the century.  The limited agricultural land and water represent the main boundaries to meet the food demand of a growing population (Davis et al., 2014, 2017). Moreover, availability of natural freshwater is expected to furtherly decline in future due to climate change (Rodell et al., 2018) – especially in arid regions – and, thus, there is an urgent need to reshape the agricultural system to sustainably feed a global population approaching 9 billion people in the next century (Godfray et al., 2010).

Food security in the Nile Basin is strictly related to the availability of freshwater resources, which are increasingly threatened by climate change and future demographic trends. Currently, food production is insufficient to meet the population food demand, and all Nile countries are currently net food importers. Healthy food is also needed to address malnutrition within the poorest rural communities in the Nile countries. Countries in the Basin are highly affected by undernourishment - linked low dietary energy - iron-deficiency-induced anemia and diabetes. The agricultural sector is the largest consumer of the Nile waters and, thus, the state of the food system has profound implications for attaining water security in the Nile Basin (NBI, 2020).

In this study we suggest a sustainable agricultural strategy to enhance sustainable a food system within the Nile River Basin. We couple the WATNEEDS hydro-agrological (Chiarelli et al., 2020) model with a linear optimization algorithm to reshape the current cropland with the aim of producing more healthy food, with several benefits for the ecosystem (e.g., reduced irrigation water consumption) and human health. Cropland redistribution can be coupled with agricultural intensification and diet shift generating, at the meso-scale, benefits in terms of irrigation water savings and increase in food self-sufficiency. We first evaluated the amount of irrigation water and the crop production related to the current crop distribution and second, we identified potential differences in food production and water consumption between the current and optimized crop distributions. We use the WATNEEDS model to quantify spatially distributed crop water requirements, - namely blue and green water requirements - which are the volumes of water needed to compensate crop water losses through evapotranspiration. Our results show that crop redistribution increases food availability and, thus, the percentage of population sustained sustainably with the local agricultural production, reducing the pressure on the currently available renewable freshwater resources of the Nile.

How to cite: Sardo, M., Rulli, M. C., and Chiarelli, D. D.: Sustainable agricultural strategies to address limited freshwater availability and meet food demand in the Nile River Basin, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15582, https://doi.org/10.5194/egusphere-egu23-15582, 2023.

EGU23-15681 | Orals | ERE1.8

Coffee Agrosystems and Climate Change 

Raniero Della Peruta, Valentina Mereu, Donatella Spano, Serena Marras, and Antonio Trabucco

Coffee is one of the most important agri-food systems from a global economic point of view. Most of the production takes place on small and medium-sized farms and is the main source of income for many rural families in several developing countries. Areas suitable for coffee production are very biodiverse and ecologically important, thus negative impacts should be minimized.
Coffee production requires special environmental and climatic conditions. Current and future climate changes could cause problems for a sustainable production and result in lower yields. To overcome these problems, it is necessary to investigate the effectiveness of possible adaptation measures, such as intercropping with other tree species that can provide more shade to coffee plants and favour environmental sustainability. 
In order to study how such modifications could improve the resilience and sustainability of coffee production, the use of process-based models can be very useful. The DynACof model was developed specifically to simulate coffee farming systems, including phenological development, physiological processes related to flower and fruit production, carbon allocation, the effect of water availability, light and temperature, as well as management. We tested the DynACof model on some study areas in Mexico, Brasil and Rwanda and verified that the yield predictions were in line with the observations. We then developed a modelling tool where the model can be applied to entire geographical areas in a spatially explicit manner, using global climatic and soil datasets.
We used this tool to simulate yields in Latin America and Africa, both for the period 1985-2014 and for the period 2036-2065 using climate projections. Comparing the two periods, the model predicts a decrease in yields of about 28% in Latin America and about 12% in Africa. We then simulated specific management options (e.g. agroforestry shading vs intensive monocropping) to assess their efficacy in enhancing environmental sustainability and resilience to climate risks. These impact analyses will be crossed with socio-economic indicators for a more comprehensive climate risk assessment to support adaptation recommendations.

How to cite: Della Peruta, R., Mereu, V., Spano, D., Marras, S., and Trabucco, A.: Coffee Agrosystems and Climate Change, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15681, https://doi.org/10.5194/egusphere-egu23-15681, 2023.

EGU23-15686 | Orals | ERE1.8

Elucidating climate change adaptation potential of improved maize (Zea mays L.) varieties with crop modelling 

Abel Chemura, Ponraj Arumugum, Eresi Kutesa Awori, and Christoph Gornott

The threats to crop yields are projected to increase under climate change and one of the most promising adaptation measures is for farmers to adjust their crop varieties over time to minimize climate risk. An improved or modern variety is a new variety of a plant species which produces higher yields, higher quality or provides better resistance to plant pests and diseases while minimizing the pressure on the natural environment. Selecting best maize varieties for various sites is also a good agricultural practice that can increase current yields in many low-productivity areas.  In this study, we aimed at identifying the climate change buffering potential of improved maize varieties using a spatialized DSSAT model using a case study across Uganda. We calibrate the model with observed weather data and then replace the weather files with climate projections from the ISIMIP3b. Model evaluation showed that the model performance was satisfactory with a correlation  coefficient (r) of 0.89, coefficient of determination (R2) of 0.79, index agreement (d) of 0.83 with observed yields. The impact of climate change on maize yield show spatial and temporal disparities with general trends showing that they worsen with time (2030 to 2090) and scenario (SSP1-RCP2.6 to SSP3-RCP7.0). At the national level, we project a yield loss of 6.2% (SSP1-RCP2.6) and 4.4% (SSP3-RCP7.0), by around 2030, 8.6% (SSP1-RCP2.6) and 14.3% (SSP3-RCP7.0) by around 2050, and 8.8% (SSP1-RCP2.6) and 26.8% (SSP1-RCP7.0) by around 2090. Switching to an improved variety results in at least double the maize yield under current climatic conditions (113.2%) compared to the current varieties, with maize yield exceeding 10 t/ha in the south-western, western and eastern parts of the country.  This positive yield effect was realized across all grids but substantially varied from around 10% to 500% yield change. Comparing the effect of climate change with an improved variety versus with a conventional variety shows it is always better to use an improved variety under climate change (positive effect), especially under worse case climatic conditions(2.9% and  8% yield buffering by 2090 under  SSP1:RCP2.6 and SSP3:RCP7.0 respectively) at national level. We therefore conclude that improved maize varieties offer a more durable solution to adapt to climate change and seed systems should therefore be strengthened to increase access to improved maize varieties for farmers.

How to cite: Chemura, A., Arumugum, P., Awori, E. K., and Gornott, C.: Elucidating climate change adaptation potential of improved maize (Zea mays L.) varieties with crop modelling, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15686, https://doi.org/10.5194/egusphere-egu23-15686, 2023.

EGU23-16211 | ECS | Posters on site | ERE1.8

Management Options to Improve Drought Resilience in Sugar Beet 

Sabrina Santos Pires, Gernot Bodner, and Christine Stumpp

Weather-extreme events are increasingly common due to climate change, with longer periods of drought and periods of strong rainfall. Drought periods are a problem in agriculture with several crops suffering from qualitative and quantitative yield reduction depending on the crop growth stage. Sugar beet (Beta Vulgaris) makes up 20% of sugar production worldwide and is the main source of sugar in temperate regions, with a recent increase in its use for biofuel production. The search for drought-resistant varieties of sugar beet with lower water requirements is expanding, however substantial variability in drought resistance regarding yield and quality has not been found so far. The goal of this study was to develop strategies to improve yield security in sugar beet cultivation under low water availability conditions. Therefore, two field experiments were established at sites representative of Austrian sugar beet production (Oberhausen, Marchfeld; Guntersdorf, Weinviertel) over the course of two years, 2020 and 2021. The experiments involved combining breeding strategies (variety selection) with agronomic approaches (soil management, land cover, irrigation, fertilization) to investigate the sugar beet's response to water stress and assess the performance of different sugar beet varieties, leading to a more climate-resilient sugar beet crop. Direct methods of measuring soil hydraulic properties (e.g. via soil moisture sensors) and plant properties (e.g. stomata density and conductance) with stable isotope analysis for carbon and water were combined. As a result, a significant yield increase was found in irrigated plots. Nitrogen fertilization had a detrimental effect when applied extensively. A yield increase was obtained by soil coverage with wooden chips in both years and sites. Furthermore, the choice of variety also played an essential role, especially regarding the trade-off between drought resistance and yield.

How to cite: Santos Pires, S., Bodner, G., and Stumpp, C.: Management Options to Improve Drought Resilience in Sugar Beet, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16211, https://doi.org/10.5194/egusphere-egu23-16211, 2023.

EGU23-16316 | Orals | ERE1.8 | Highlight

Cross-border environmental impacts of agri-food systems and potential solutions towards sustainability: a case study of trade between Europe and Africa. 

Ertug Ercin, Brecht D’Haeyer, Corjan Nolet, Emrah Alkaya, Didem Mahsunlar, Tolga Pilevneli, and Goksen Capar

Some nations and regions, such as the European Union (EU), use food ingredients and agri-food products that are not produced within their borders while being essential for their food security and food systems. This product flow through international trade means that these regions are connected to water resources outside their borders. It also means they create subsequent environmental and social effects in the original production locations, a phenomenon called ‘cross-border impacts”.  For example, these imports can be a substantial part of existing problems of water depletion and pollution in producing regions since every step in the food system such as growing, harvesting, transportation, production, packaging, and retail consume and pollute water. Furthermore, agricultural production in exporting regions provides the lion’s share of greenhouse-gas emissions from the food systems.

This study first maps the cross-border environmental footprints of agri-food systems in Europe (water and carbon footprints) along the supply chain of major imported agri-food products from Africa. Second, it determines the vulnerability of these agri-food systems to climate change. Third, it identifies potential solutions to minimize the vulnerabilities and environmental impacts of the agri-food systems that are connecting Europe and Africa.

The study shows that the cross-border environmental impact of European agri-food systems on Africa is largely related to imports of oranges, potatoes, grapes, tangerines, and tomatoes. For example, the water footprint of this trade is approximately 5 km3 per year.  These products originate from water-scarce areas such as North Africa (Egypt, Morocco) and South Africa. Furthermore, climate change will reduce water availability in these regions, e.g., 20% less water is expected in North African countries by 2050.

Minimization of food loss and waste along the supply chain of the Europe-Africa trade is investigated as a potential solution to reduce the environmental footprint of this trade. It is found that around a 30% reduction in water footprint can be achieved by eliminating food waste at the consumer level in Europe. Further reductions in environmental impacts can be achieved if manufacturing and transportation losses are minimized as well, up to 10% and 20% reductions in the water footprint and carbon footprint, respectively. Another solution to reduce the footprint of agri-food systems is to source relevant products locally instead of importing from Africa. This option significantly reduces carbon footprints (up to 60%) but not much for water footprints (around 10% reduction). For some food items such as oranges, more water can be saved if they are imported from Africa rather than locally produced in Europe.

This study concludes that the sustainability of agri-food systems has a cross-border dimension, which is mostly neglected in national policies of sustainable production and consumption. The sustainability of such imported agri-food products can be understood by assessing their environmental impacts at production locations. Improving production efficiencies at exporting regions (e.g., reduction of production losses and waste) and minimizing waste of these products at consumer levels can help reduce the environmental consequences of this trade and help achieve our sustainability goals.

How to cite: Ercin, E., D’Haeyer, B., Nolet, C., Alkaya, E., Mahsunlar, D., Pilevneli, T., and Capar, G.: Cross-border environmental impacts of agri-food systems and potential solutions towards sustainability: a case study of trade between Europe and Africa., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16316, https://doi.org/10.5194/egusphere-egu23-16316, 2023.

With increasing global demand for oil and gas, the exploration of unconventional resource plays (shale oil and gas) continues to gain relevance. Such plays could be significant for maximising the production value in proven geological basins, allowing the exploration of a cleaner fossil fuel. Unconventional resources could play a part in the energy transition to lower-impact CO2 fuels while meeting current energy security needs.

For several decades, the UK North Sea has been a prolific oil and gas province, with numerous conventional oil and gas discoveries sourced predominantly by the Kimmeridge Clay Formation (KCF). In this study, we have used 3-D geostatistical modelling of the distribution of key geochemical and geomechanical properties for the KCF to investigate the potential of shale oil and gas plays within Quadrant 15 in the Outer Moray Firth region of the UK North Sea.

The utilized geochemical and geomechanical property logs were generated from sixteen selected drilled wells using machine learning and established property equations, while the top and base KCF structural depth maps used for modelling were created using grid- and isopach creation tools in Zetaware's Trinity software, an existing Base Cretaceous Unconformity (BCU) map of the UK North Sea and well top information from 58 wells within the study area.

The geostatistical property maps created for the KCF in Schlumberger’s Petrel software were then normalised and integrated to identity sweet spots for potential shale oil/gas exploitation, after the application of various cut-offs using standard industry thresholds for unconventional resources.

The modelling results suggest that the KCF show good potential for shale oil and gas exploitation within the central part of the Witch Ground Graben and limited areas of the Piper Shelf and Claymore-Tartan Ridge in the study area.  Further investigations on maturity, saturation and producibility will be conducted by 3-D basin modelling.

How to cite: Akinwumiju, A.: Sweet-spot mapping of the Kimmeridge Clay Formation in the UK North Sea for unconventional resource exploitation using a geostatistical modelling approach, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-63, https://doi.org/10.5194/egusphere-egu23-63, 2023.

EGU23-543 | ECS | Orals | ERE1.9

Subsurface mechanical modeling of Krishna Godavari basin using petrophysical properties of the rocks by utilizing 3D seismic and well log data sets 

Gagandeep Singh, Anjeeta Rani, William K. Mohanty, and Aurobinda Routray

Three-dimensional seismic data and well-log data analysis deliver complete information on the petrophysical characteristics of reservoir rock and its fluid content. The current study shows the combined interpretation of 3D seismic data and well log responses such as gamma ray, delay time (DT)- P wave and S wave, resistivity, neutron, density, and lithology logs from eight wells under the research area of Krishna-Godavari (KG) basin. The main target of the paper is focused on the prominent positive topographic features in the bathymetry data and on the porous and fractured/faulted hydrocarbon rocks. Fluid/gas migration characteristics like acoustic voids, chimneys, and turbid layers may be seen in the present mounds. Coherence, dip, curvature, and saliency attributes are used to enhance the discontinuities within the seismic volume. After then, well logs were used to identify the hydrocarbon-bearing zones. Finally, the seismic to well tie step was initiated, and the complete earth model of the given data was generated.

The goal of this paper is to describe the offshore KG basin reservoir areas, in a qualitative way using 3D seismic and well log data and its possible correlation with facies. The possible data and wells information are conjugated with other attributes, which are relatively recent methods in this field study, yet it is crucial to reducing geological uncertainty and predicting facies. The characterization of reservoirs using only the seismic volume (impedance dependent data) characteristics is difficult due to the shally environment of the area, which might obscure reservoir identification. As a result, combining a variety of techniques and data is important for better understanding geological settings and identifying meaningful geological features in the shally environment of the KG basin.

How to cite: Singh, G., Rani, A., Mohanty, W. K., and Routray, A.: Subsurface mechanical modeling of Krishna Godavari basin using petrophysical properties of the rocks by utilizing 3D seismic and well log data sets, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-543, https://doi.org/10.5194/egusphere-egu23-543, 2023.

EGU23-1319 | ECS | Posters on site | ERE1.9

Effects of Thermal Shocks on Cement for CCS under Confined and Unconfined Conditions 

Kai Li and Anne Pluymakers

In wells for carbon capture and storage (CCS), fractures can develop in the cement due to strong thermal shocks upon pressurized CO2 injection into the subsurface. The network of these fractures forms leakage pathways that can impair well integrity, and thus impede successful geological storage of CO2. In this study, we investigate how thermal shocks affect cement integrity under unconfined and confined conditions. Solid cylindrical samples (Φ3 x 7 cm) and samples of the same size but with a hole (Φ4 mm) in the middle are used. All samples are prepared using class G cement with 35% BWOC silica flour by Halliburton AS Norway, in accordance with API specification 10B-2. In unconfined experiments, we either quench the solid sample into cold water or inject cold water through the hollow-cylindrical sample to induce thermal shocks. In confined experiments, we mount the hollow-cylindrical sample in a triaxial deformation setup with confining pressure and axial stress, then inject cold water to induce the shocks. Before the shocks in all experiments, samples have been heated to 130°C. The temperature of the water is 5°C to achieve a strong thermal shock as possible. We produce eight cycles of thermal shock in all experiments. To study the extent of cracking, we use a micro-computed tomography (μ-CT) scanner to characterize the network of pores and fractures in the cement before and after experiments.

Under unconfined conditions, fractures develop in cement after thermal shocks in both quenching and injecting-through experiments. Both experiments generate sufficient thermal stresses to cause cracking in cement. In quenching, multiple fractures are initiated at different orientations. However, by injecting cold water through the sample, only one longitudinal fracture is created. This fracture is intersected with the injecting hole, where most thermal stresses are built up. The volume ratio of pores and fractures in samples increases to 2.74% by quenching and 1.84% by injecting through respectively, from 0.38%. Compressive strength decreases from 97.9 MPa for intact samples to 53.9 MPa after quenching, and 83.6 MPa after the injecting-through experiment. Under confined conditions, we carry out injecting-through experiments to bring about thermal shocks under 1.5 and 10 MPa confining pressure. We haven’t observed any failure in cement integrity under either confinement. Instead, compressive strength increases by 6.2% and 7.2%, and the volume ratio of pores and fractures decreases by 7.7% and 18.2% after the experiment under the confinement of 1.5 and 10 MPa, respectively. This means the presence of confining pressure not only hinders the adverse effects of thermal stresses on cement integrity but also compacts the samples. Higher confining pressure causes more compression to the sample, then resulting in greater strength.

How to cite: Li, K. and Pluymakers, A.: Effects of Thermal Shocks on Cement for CCS under Confined and Unconfined Conditions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1319, https://doi.org/10.5194/egusphere-egu23-1319, 2023.

EGU23-1627 | Orals | ERE1.9

Viscosity-reducing and Biosurfactant-producing Bacterial Consortia Isolated from Low-permeability Reservoir in Ordos Basin 

Ziwei Bian, Zena Zhi, Xiangchun Zhang, Yiqian Qu, Lusha Wei, Yifei Wu, and Hanning Wu

Many bacteria have been proved to change physical (viscosity, wettability, and tension), and compositions of crude oil, which can make it easier for oil to be released from rock pores and achieve the purpose of improving recovery, which is called Microbial Enhanced Oil Recovery (MEOR). Our team has previously isolated six emulsified and viscosity-reducing bacteria (Bacillus. sp.) in low permeability layers (Chang 4+5 and Chang 6) of Ordos Basin. However, environmental tolerance of the strains is limited, and the components of crude oil used by the strains were also different. The combination of strains of different species and genera may enhance the effects of single bacteria, surpass the tolerance upper limit, and optimize the viscosity reduction and degradation. Therefore, in this study, it is extremely necessary to study the bacterial consortium. Two consortia were obtained and each consortium consisted of three bacterial strains and was designated as Consortium A (51+61, 61+H-1, 51+H-1; A-ALL) and Consortium B (34(2)+42, 34(2)+A-3; 42+A-3. B-BLL). The performance of the mixed strains was evaluated by the analysis of change in emulsification rate, crude oil composition, viscosity, and the tolerance (temperature, salinity, and pH) though GC-MS, rotational rheometer, and other methods. The results showed that bacterial consortiums had higher alkali resistance and could survive temperatures of 55 °C and salinity of 50 g/L in comparison to single bacterium. The emulsification rate was 22%-48%. Consortium B has better effects than Consortium A. The viscosity reduction rate of the Consortium A after 7 days was exceeded 30% as a whole, and the rate of Consortium B was more than 35%. The crude oil of Consortium B is basically non-stick to flask. Compared with single bacteria, the utilization components of crude oil to bacteria are still different, including both long chain hydrocarbons and short chain hydrocarbons. However, the proportion of long chain n-alkanes is further reduced compared with that of single bacteria, and the highest ratio is reduced by 23.81% (B-ALL). Overall, the bacterial consortium outperforms the single strain in terms of tolerance, viscosity reduction, and degradation, which further optimizes the application of MEOR.

How to cite: Bian, Z., Zhi, Z., Zhang, X., Qu, Y., Wei, L., Wu, Y., and Wu, H.: Viscosity-reducing and Biosurfactant-producing Bacterial Consortia Isolated from Low-permeability Reservoir in Ordos Basin, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1627, https://doi.org/10.5194/egusphere-egu23-1627, 2023.

EGU23-1648 | ECS | Posters on site | ERE1.9

The CO2 storage in coal seams at the influence of coal fines migration 

Qian Wang, Jian Shen, Paul.W.J. Glover, and Piroska Lorinczi

Abstract: the pressure of the coal seam decays to a certain value due to the production of CH4, the production wells are switched to CO2 injection wells. The injection of CO2 can improve the CH4 recovery and realize the CO2 geological storage.The reverse migration of coal fines produced in the CH4 development stage can be caused by CO2 injection, which blocks the pore-thorats and fractures in coal seams and increases the difficulty of CO2 injection. We carried out experiments on coal fine migration and CO2 injection and storage at reservoir conditions on the simulated coal seam, which was a composite core composed of different types of coal. We focus on the migration of coal fine in simulated coal seam and the impact on CO2 storage. The experiment results show that, the permeability of the combined core, which is composed of proppant fractured coal, fractured coal and matrix coal in turn, decreases by 40.6% after being injected with 300ml of coal fine suspension with a concentration of 1g/1L. This is due to the deposition or capture of coal fines during the suspension injection, resulting in surface adsorption, bridging blockage, and direct blockage in the pore space, which seriously damaged the connectivity of the coal pore space. The proppant fractured coal can filter 77.1% of the coal fines in the suspension, and the fractured coal rock can filter the remaining 23.9% of the coal fines. The average CO2 storage capacity and CO2 storage efficiency of the composite core increased by 4.47 cm3·g-1 and 10.8%, respectively after subsequent CO2 injection into the composite core. The corresponding injection pressure difference also increased by 32.5%, and a CH4 recovery improvement of 13.6% is obtained.The migration and balockage of coal fines lead to the most significant improvement of CO2 storage in fractured coal (14.4%), followed by proppant fractured coal (10.3%), and the worst improvement of CO2 storage in matrix coal (3.4%). The migration of coal fines improves the CO2 storage effect in fractured coal seams to a certain extent, but increases the difficulty of CO2 injection, which is not conducive to the CO2 storage of the reservoir.

Keywords: CO2 storage, coal seams, coal fines migration, proppant fracture

How to cite: Wang, Q., Shen, J., Glover, P. W. J., and Lorinczi, P.: The CO2 storage in coal seams at the influence of coal fines migration, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1648, https://doi.org/10.5194/egusphere-egu23-1648, 2023.

EGU23-2016 | Posters on site | ERE1.9

GEOMODELATOR – from static geologic models to structured grids for numerical simulations 

Benjamin Nakaten and Thomas Kempka

Conversion of static geologic models into numerical simulation grids is a pre-requisite to undertake site-specific assessments of geologic subsurface utilisation in terms of risk assessments, design and operational optimisations as well as long-term predictions.

GEOMODELATOR is a Python-based Open Source software package which enables modellers to translate static geologic models into regular structured simulation grids with element partitions following a complex model geometry.

For that purpose, geologic models generated by means of Geographic Information Systems (GIS), Computer-Aided Design (CAD) or other specific geologic modelling software packages are integrated in form of point cloud data together with the desired structured simulation grid geometry.

GEOMODELATOR maps geometric features such as lithologic horizons, faults and any kind of other geometric data by 3D Delaunay triangulation onto the pre-defined grid element centres, and provides the modeller with Visualization Toolkit (VTK) data and Python numpy arrays for visual model inspection and their direct application in numerical simulations, respectively.

The present contribution shows the application of GEOMODELATOR to different numerical simulation studies addressing fluid flow as well as transport of heat and chemical species in geological subsurface utilisation.

How to cite: Nakaten, B. and Kempka, T.: GEOMODELATOR – from static geologic models to structured grids for numerical simulations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2016, https://doi.org/10.5194/egusphere-egu23-2016, 2023.

EGU23-2535 | ECS | Orals | ERE1.9

Composition of pure shale oil with medium-high maturity 

Ming Li, Ming Wang, and Jinbu Li

Continental shale oil can be divided into two categories according to vitrinite reflectance of kerogen: medium-high maturity (Ro > 0.9%) and medium-low maturity (Ro ≤ 0.9%). Due to high ratio of gaseous (C1-5) and light hydrocarbons (C6-14), high GOR and overpressure of the shale section, medium-high maturity shale oil has commercially productivity, which is considered as the target of unconventional resources in China. Shale oil composition is the basic and key parameter for resource evaluation, prediction of favorable areas, well location and field development plan. However, in shale oil composition research projects, the samples used and the analytical methods are quite different, and evaluation standard has not been established, which has restricted the exploration and exploitation of continental shale oil in China.

To understand this effect, we took the first member of Qingshankou Formation (Late Cretaceous) in Songliao Basin in eastern China as the target section. The section develops pure shale oil at a burial depth of 2000-2500m, with vitrinite reflectance of kerogen (Ro) of 1.20%-1.70% and high clay minerals content (40 wt%-60 wt%). We performed four sets of experiments on molecular composition of shale oil, including oil produced from shale section, the full-closure coring shale, the conventional coring shale and extracted hydrocarbons of shale with chloroform. The crude oil and saturated hydrocarbons (extracted hydrocarbons) separated by chromatographic column were directly analyzed by gas chromatography. The full-closure coring and conventional coring shale samples were conducted TG-GC (thermogravimetry-gas chromatography) experiment, where the powder samples were thermally desorbed at 300 ℃ for 3 minutes.

The experimental results show that carbon number of n-alkanes in crude oil is 4–38. The carbon number of n-alkanes in full-closure coring shale is 1–26, and it contains a large amount of gaseous and light hydrocarbons, accounting for up to 60 wt%–80 wt%. It is worth noting, however, that due to the loss of gas and light hydrocarbons in conventional coring, the carbon number of n-alkanes in conventional coring shale is 11–26, and the main peak carbon is 13–16. In the process of shale placement in core library, extraction and concentration, a large amount of hydrocarbons are lost. Through chromatographic analysis, carbon number of n-alkanes in saturated hydrocarbons is 15-38, and the main peak carbon is 18–22. C15- components are totally lost in extraction (Figure 1).

The comparison data we assembled show that shale oil components obtained from different samples vary significantly, especially for medium-high maturity shale containing large amounts of gaseous and light hydrocarbons. The heavy hydrocarbon components (C15+) can be determined by combining the produced oil with extracted hydrocarbons, and the gaseous and light hydrocarbons retained in shale can be determined by combining the produced oil with TG-GC analysis for full-closure coring shale. Pressure-retained coring or full-closure coring is indispensable for obtaining shale oil components in place.

Figure 1 (a) Gas chromatogram of oil produced from shale section; (b) TG-GC chromatogram of conventional coring shale sample; (c) TG-GC chromatogram of full-closure coring shale sample; (d) Gas chromatogram of saturated hydrocarbon extracted from shale sample.

How to cite: Li, M., Wang, M., and Li, J.: Composition of pure shale oil with medium-high maturity, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2535, https://doi.org/10.5194/egusphere-egu23-2535, 2023.

EGU23-3107 | ECS | Orals | ERE1.9

Stereoscopic Development Adjustment Mode for Enhanced Oil Recovery in Mature Multi-Layer Oilfield 

Lingbin Lai, Cunyou Zou, Zhibin Jiang, Haibin Su, Xuyang Zhang, Songlin Li, and Hualing Zhang

After a long period of water flooding development, oilfields will enter the production stage of "high water cut, high recovery degree, and low oil recovery rate". On the one hand, due to the displacement effect of the water injection, some oil layers already reached the water flooding limit. On the other hand, due to the effect of reservoir heterogeneity, dominant seepage channels, and imperfect injection-production well pattern, some oil layers are enriched with a large amount of remaining oil. Unbalanced production of reservoirs and difficulty in development and adjustment are common problems in mature oilfields. Mature multi-layer oilfields generally develop many sets of oil-bearing layers vertically. After a long water injection period, the water-flood law and the remaining oil distribution are complex, and the production of different well patterns or strata varies greatly. Through strata and well pattern reorganization, combined with the evaluation results of water flooding adjustment potential, some reservoir engineers and researchers established a stereoscopic development adjustment mode for enhanced oil recovery in mature multi-layer oilfields. This paper summarizes the main technologies of stereoscopic development adjustment mode for enhanced oil recovery in mature multi-layer oilfields. The main technologies of stereoscopic development adjustment mode include research on the remaining oil distribution, evaluation of water flooding adjustment potential, selection of tertiary oil recovery methods, reorganization of strata and well pattern, and optimization of timing from water flooding to tertiary oil recovery, etc. For strata with low water flooding adjustment potential, the tertiary oil recovery well pattern is reorganized and tertiary oil recovery is adopted to improve oil recovery. For strata with large water flooding adjustment potential, the water drive well pattern is reorganized and water flooding development is used to excavate the remaining oil. As for strata with general water flooding adjustment potential, the tertiary oil recovery well pattern is reorganized and water flooding development is used to excavate the remaining oil first, and then transfer to tertiary oil recovery at the proper time. The stereoscopic development adjustment mode is applied to test block K of Q reservoir which is a mature multi-layer oilfield. After stereoscopic development adjustment, the development effect of test block K meliorates. It is estimated that the EOR will be increased by more than 8% after stereoscopic development adjustment in test block K.

How to cite: Lai, L., Zou, C., Jiang, Z., Su, H., Zhang, X., Li, S., and Zhang, H.: Stereoscopic Development Adjustment Mode for Enhanced Oil Recovery in Mature Multi-Layer Oilfield, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3107, https://doi.org/10.5194/egusphere-egu23-3107, 2023.

EGU23-3408 | Orals | ERE1.9

Optimising the drilling process for geothermal wells using legacy oil field data and machine learning 

Andrew Kingdon, Matthew Arran, Mark Fellgett, Shahin Jamali, Henning Knauer, and Kevin Mallin

Deep geothermal heat represents a massive opportunity to provide low-carbon district heating for towns and cities. Space heating represents a large percentage of total energy use in Northern Europe; nearly 40% of all UK energy use (BEIS, 2022) is for heating, predominantly from natural gas. Global pressures on the international gas market and the urgent need to decarbonise the heating system to deliver NetZero highlight the need for identifying renewable heat sources to replace gas.

However, finding reliable high temperatures requires drilling to several-kilometres depth. Achieving sustainable heat supply, without depletion, means that wells must intersect deep permeable strata which are impossible to detect from the surface. Well prognosis is therefore heavily reliant on data from legacy drilling. Drilling is always an expensive process and any operational issues can impose significant additional costs, as rigs capable of drilling such boreholes have rental rates of many €1000s per day. Even when the drilling is completed, financial returns are slow and reaching profit takes years. Therefore, reassuring investors requires de-risking such projects through mitigating avoidable additional costs.

Digital data from wells penetrating many kilometres are needed for understanding subsurface processes. Only small numbers of deep geothermal wells have been drilled, so the best alternatives are legacy hydrocarbon exploration boreholes; these are good analogies for geothermal wells as they rely on permeability at depth. Such legacy hydrocarbon data are increasingly openly available through National Data Repositories (NDR) and/or Geological Survey Organisations. 

The EU Horizon programme funded OptiDrill project (101006964) is using legacy well data to optimise the drilling process, by linking drilling parameters with petrophysical data to understand the constraints upon the drilling processes. This will allow causes of interruptions to drilling and unnecessary down-time to be assessed and hopefully eliminated.

NDR archives have been trawled for modern drilling and logging data that admits optimal analysis. An Isolation Forest machine-learning algorithm was used to analyse Measurement-While-Drilling derived Rate-of-Penetration data and geophysical log data, identifying zones of anomalous responses quickly and without supervision. Examination of newly available daily drilling reports (DDR) data, from the NDR, allows these anomalous responses to be associated with breaks in drilling operations and their causes to be understood. This allows both refinement of the anomaly-detection algorithm for the identification of drilling problems, and differentiation between problems caused by drilling or geological issues and those caused by operational and logistical difficulties (e.g. procurement delays). Where drilling issues are identified these can be used to develop remediation strategies for future wells drilled in similar conditions, through revised drilling programmes and optimised well designs that minimise avoidable drilling operations such as unnecessary round trips etc.

How to cite: Kingdon, A., Arran, M., Fellgett, M., Jamali, S., Knauer, H., and Mallin, K.: Optimising the drilling process for geothermal wells using legacy oil field data and machine learning, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3408, https://doi.org/10.5194/egusphere-egu23-3408, 2023.

Reservoir heterogeneity is one of the key geological problems in the process of oil and gas exploration and development of clastic rocks. Understanding reservoir heterogeneity is imperative to improve the effectiveness of exploration and development. The primary porosity calculation model proposed by the authors in the previous study is used to calculate the primary porosity of samples from modern braided river sands and sandstone outcrops of braided sand bodies, and the primary porosity heterogeneity (PPH) model of the braided sand body is established. The architectural-elemental structures of braided sand bodies have obvious control effects on the distribution of its primary porosity heterogeneity. The central braided channel and braid bars have strong primary physical properties; the primary porosity is high and always greater than 38%. The contact areas between the braided channel and braided bars have a low value of primary porosity and are always lesser than 33%. The distribution characteristics of the present porosity of braided river reservoirs are also influenced by sedimentary architecture. To compare the relationship between PPH, present porosity heterogeneity (pPH), and sedimentary architecture (SA), the images of PPH, pPH, and SA were digital, graying, and normalized. The digital image Q-Q plots of the distribution probability of PPH, pPH, and SA are calculated. The results show that: the Q-Q plots of the probability distribution of present porosity and architectural-elemental structures (or lithofacies) can reflect the influence and degree of primary porosity and diagenesis on the present heterogeneity of the reservoir. The Q-Q plots of distribution probability primary porosity and present porosity identify the distribution areas; the points are always distributed on different lines. The line ‘y = x’, is derived from compaction and primary porosity; the line ‘y = ax, a > 1’, is derived from diagenesis, which is unfavorable to the reservoir porosity preservation (such as cementation); the line ‘y = ax, a < 1’ is derived from diagenesis, which is beneficial to reservoir porosity preservation (such as dissolution). Based on the Q-Q plots of distribution probability, the influence from primary porosity and diagenesis can be quantitatively analyzed. The influence of primary porosity on pPH in braided sand bodies of Ahe formation (Kuqa depression), middle Jurassic fluvial sandstone (Datong basin), and Karamay Formation (Junggar basin) were 19%, 90%, and 10%, respectively. A quantitative probability distribution Q-Q model of reservoir PPH and pPH is effective for reservoir physical modeling.

How to cite: Yiming, Y., Liqiang, Z., Shuai, J., and Zuotao, W.: The primary porosity heterogenetic model of braided river sandstone reservoirs and its influence on the present porosity heterogeneity in the Kuqe depression, Tarim basin, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6856, https://doi.org/10.5194/egusphere-egu23-6856, 2023.

EGU23-7034 | Posters on site | ERE1.9

Study on Hydraulic Resistance Damage Law of External Liquid Intrusion in Tight Sand Conglomerate Reservoir 

Jianbang Wu, Shenglai Yang, and Qiang Li

In geological resource exploitation engineering such as reservoir development, the intrusion of foreign liquid will cause water lock damage to the formation rock structure, which affects the effect of reservoir transformation such as CO2 sequestration. The tight sand conglomerate reservoir is characterized by high content of expansive clay minerals, high capillary pressure, small pore throat, and serious heterogeneity, which leads to serious water lock damage. The extent, mechanism and reasonable prediction of damage are the concerns of the engineering community.
In view of this problem, this study uses the laboratory long core experiment method based on nuclear magnetic resonance (NMR) monitoring to simulate and study the reservoir damage law before and after the invasion of foreign liquid into the formation. The damage distance of liquid resistance and influencing factors were studied, and a prediction model was established. The long core experiment used drilled natural cores with a total length of 45 cm that were spliced from short cores with a diameter of 2.5 cm. A total of five pressure points were set up at 10 cm intervals to monitor the pressure gradient. The pressure gradient changes along the long core after saturated oil and water intrusion were tested separately. A new method of calculating the range and degree of water lock damage zone based on pressure gradient was established. According to the damage control factors obtained from the experimental study, the prediction model of water lock damage with the transformation from multiple nonlinear problems to linear problems is established by using permeability, porosity and content of water-sensitive clay minerals as input conditions.
The results show that the physical property of reservoir plays a decisive role in the damage distance of liquid resistance. The foreign liquid intrudes into the formation has obvious characteristics of "three zones", and the "pressed liquid stop zone" is the main factor controlling the damage degree of liquid resistance. Physical property, lithology and expansibility clay mineral content together constitute the 0-1 judgment value to determine the time-varying damage of fluid resistance in reservoir. The accuracy of the established multiple nonlinear regression prediction model of liquid resistance damage is greater than 80%, which can be used to quantitatively predict the liquid resistance damage degree of underground reservoir when it is difficult to conduct indoor simulation experiments in the evaluation of water intrusion damage degree.

How to cite: Wu, J., Yang, S., and Li, Q.: Study on Hydraulic Resistance Damage Law of External Liquid Intrusion in Tight Sand Conglomerate Reservoir, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7034, https://doi.org/10.5194/egusphere-egu23-7034, 2023.

EGU23-8226 | ECS | Posters on site | ERE1.9

Hydrogeochemical impacts of pumped hydropower storage in open-pit lignite mines 

Tobias Schnepper, Michael Kühn, and Thomas Kempka

Large-scale energy storage is becoming more important due to the increase in electricity generation from renewable sources and the related grid balancing requirements. In this context, Pumped Hydropower Storage (PHS) in former open-pit lignite mines can substantially contribute to energy supply safety. Assuming an average storage capacity of 150 MW per open-pit mine, PHS could generate a power output of at least 6 GW in European mines which will be abandoned in the next two decades. Experiences from mine-flooding across Europe demonstrate that hydrogeochemical processes can become a critical environmental and economic factor for the realisation of such projects. Depending on sulphide and oxygen availability, buffer capacities and dilution processes, mine waters with increased acidity as well as elevated sulphate and metal concentrations can pose a threat to adjacent ecosystems, groundwater resources and the installed PHS infrastructure.

We present a generic parameter study by means of numerical simulations to predict changes in the mine water composition as a result of PHS operation in different hydrogeochemical settings. Published datasets on hydrogeochemical, hydrogeological and technical conditions with a focus on German mines were applied for model parametrisation. A reaction path model was developed that accounts for initial mine flooding, inflows and outflows as well as pumping and release cycles between the two reservoirs. The simulations were run until chemical equilibrium was achieved in the lower reservoir.

Simulation results indicate that the long-term availability of buffer capacities in the reservoir water and adjacent sediments determine the development of acidic or neutral mine waters. Sulphate concentrations are mainly influenced by dilution processes, emphasizing the relevance of considering additional in- and outflows. Depending on these fluxes as well as oxygen availability and initial sulphide concentration in the mine sediments, the time to reach chemical equilibrium in the lower reservoir varies significantly from several weeks to months. Furthermore, the dissolution of sulphides and carbonates as well as the precipitation of iron (oxy)hydroxides may affect the properties of the open-pit slope sediments. Their long-term stability may be altered, based on their initial mineral concentration and hydraulic conductivity.

In summary, potential impacts on water quality in the PHS reservoirs have been investigated under different hydrogeochemical settings. We conclude that, under specific boundary conditions such as the availability of sufficient buffer capacities and dilution by controlled inflows and outflows, PHS operation in abandoned open-pit coal mines can be realised from an environmental perspective.

How to cite: Schnepper, T., Kühn, M., and Kempka, T.: Hydrogeochemical impacts of pumped hydropower storage in open-pit lignite mines, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8226, https://doi.org/10.5194/egusphere-egu23-8226, 2023.

EGU23-8407 | ECS | Orals | ERE1.9

Multi-salinity core flooding study in clay-bearing sandstones, a contribution to geothermal reservoir characterisation 

Daniela Navarro-Perez, Quentin Fisher, Piroska Lorinczi, Samuel Allshorn, and Carlos Grattoni

Geothermal reservoir characterisation benefits from the oil and gas petrophysics experience in areas such as porosity and permeability estimation, rock-fluid interactions etc.. Permeability is the crucial parameter in assessing water transmissibility with geothermal reservoirs. Permeability impairment is a key worry due to rock-fluid interactions within the reservoir life cycle management. The laboratory techniques help in recreating the reservoir conditions and determining formation damage. Uncertainty increases for tight geothermal reservoirs (permeability < 1 mD), which often contain significant amounts of clay that reacts with water or ionic species during hydraulic fracturing used in Enhanced Geothermal Systems.

Clay-bearing sandstones are complex reservoirs since their clay minerals actively interact with water, causing formation damage by clay swelling and migration mechanisms. Core flooding experiments study the clay minerals' behaviour in different water conditions - e.g. salinity, electrolytes species, pH, and temperature - helping to understand the impact of clays on reservoir quality and identifying optimal conditions to reduce formation damage.

A multi-salinity experiment was undertaken to study the clay effect of three tight clay-bearing sandstones, samples A, B and C, of different reservoir provenance. Sample A has a core porosity of 18%, gas permeability of 1.28 mD, and 15.5%v/v of XRD clay minerals and kaolinite as the primary group. Sample B has a core porosity of 20.2%, gas permeability of 0.56 mD, and 37%v/v of XRD clay minerals and chlorite as the primary group. Sample C has a core porosity of 18.8%, the gas permeability of 1.95 mD, and 36.3%v/v XRD clay minerals and mica as the primary group. The experiment consisted of flooding brine with constant inflow at different salinities and monitoring the rock resistance, pressure drop, and outlet brine conductivity. High- and low-salinity batteries were flooded, ranging from 200,000-75,000 and 50,000-0 ppm NaCl respectively, at a constant room temperature of 21⁰C. In addition, the brine permeability was measured in steady- and unsteady-states techniques, and pore size distribution was NMR scanned at each run per battery.

Permeability impairment increased in all samples. Samples A (kaolinite) and C (mica) show a staggered increase in the salinity range. In contrast, sample B (chlorite) shows a peculiar upside-down trend in the low-salinity range. Clay migration was detected in the last brine runs since fines grain were released in the outflow. NMR T2 distribution shows a bimodal pore distribution for samples B and C, and the pore-throat connectivity rearranges as salinity decreases in both samples, indicating a clay swelling mechanism. The cation-exchange capacity (CEC) of samples A and C resulted in 3.7 and 3.6 meq/100g, respectively, and sample B was 71.5 meq/100g. CEC values are directly related to the clay mineral content. The highest CEC (sample B) relates to the upside-down permeability impairment with clay swelling. This investigation contributes to the geothermal reservoir characterisation in understanding how the water salinity controls the clay effect in tight clay-bearing sandstone reservoirs.

How to cite: Navarro-Perez, D., Fisher, Q., Lorinczi, P., Allshorn, S., and Grattoni, C.: Multi-salinity core flooding study in clay-bearing sandstones, a contribution to geothermal reservoir characterisation, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8407, https://doi.org/10.5194/egusphere-egu23-8407, 2023.

EGU23-9352 | ECS | Posters on site | ERE1.9 | Highlight

Repurposing of idle wells from the oil and gas industry into deep borehole heat exchangers 

Nora Koltzer, Johannes Schoenherr, Maximilian Sporleder, Sebastian Andreas Steininger, Marcel Halm, Michael Kettermann, and Florian Wellmann

The motivation behind this study is to repurpose idle wells from hydrocarbon exploration and production to provide heat for end users being located near the idle well. This is possible by prolonging the value-added chain of idle wells from the gas and oil industry by re-completion as geothermal closed loop wells. This is the most efficient way to produce green energy without drilling new wells by saving the carbon emission and costs of building a new geothermal well.

With this feasibility study we quantify the concept of re-completing idle wells in the North German Basin (NGB) into deep coaxial borehole heat exchangers. With numerical models of two typical geological settings of the NGB and two different completion schemes it was possible to simulate the thermal performance over a lifetime of 30 years. The calculated heat extraction rates are in the range of 200 kW to 400 kW with maximum values of up to 600 kW. This is higher than from already installed deep borehole heat exchangers. Sensitivity analyses demonstrate that flow rate, injection temperature and the final depths of re-completion are the most impacting parameters of thermal output determination.

In the final project stage, the heat demand around two exemplary boreholes was mapped and possible heating networks were simulated. The initial production costs for heat are comparable to other renewable energy resources like biomass and - depending on distance between source and user – well competitive against current gas prices. These calculations highlight not only the environmental valuable motivation behind the concept of repurposing idle wells but could also save capital expenditures for the geothermal industry.

Using a vacuum isolated tubing characterized by very low thermal conductivity of 0.02 W/(m*K), would make it possible to use the geothermal resources even more efficiently from idle wells. This project highlights the major potential of usable geothermal resources in already installed deep wells. The application has almost no geological risk, as the concept is independent of reservoir uncertainties like permeability and reservoir fluid composition, drilling risks are skipped completely and it is realizable at any location.

How to cite: Koltzer, N., Schoenherr, J., Sporleder, M., Steininger, S. A., Halm, M., Kettermann, M., and Wellmann, F.: Repurposing of idle wells from the oil and gas industry into deep borehole heat exchangers, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9352, https://doi.org/10.5194/egusphere-egu23-9352, 2023.

Power-to-Methanol is considered as an additional option to Power-to-Gas to convert surplus energy from renewable sources and the electric grid into storable energy carriers. In this context, methanol is an alternative fuel to power combustion engines, and it can be applied to produce chemical feedstock such as formaldehyde required for polymer production, hydrocarbons, gasoline and olefines, as well as gasoline additives and especially as an energy carrier and carbon sink.

As long-term storage of energy carriers is required to realise the transition of the energy sector to renewable sources scheduled in the European Union, the fact that storage of methanol requires less operational and safety efforts compared to natural gas or hydrogen is a significant benefit, i.e. methanol does not require any compression prior to its injection into geologic subsurface reservoirs, while being biodegradable and of generally low environmental toxicity. Existing hydrocarbon transport and storage infrastructure can be directly applied to transport and store methanol in the geologic subsurface. In this context, a major concern besides methanol biodegradability is its high miscibility with water, potentially resulting in relevant storage losses that may favour uneconomic storage operations in active groundwater aquifers. Hence, the present study aims at a quantitative assessment of the mixing behaviour of methanol and water based on a reference numerical simulation benchmark previously applied to investigate that of CH4 stored in a CO2 cushion gas within a depleted natural gas reservoir (Oldenburg et al., 2003, Ma et al., 2019, and others). For that purpose, the TRANSPORTSE numerical simulator (Kempka, 2020), applicable to simulate fluid flow as well as transport of heat and reactive transport of chemical species (Kempka et al., 2022) is used in the present study. Mixing ratio-dependent density and viscosity changes as well as different reservoir dipping angles are considered to determine the chemical storage efficiency in view of mixing losses. Simulation results demonstrate that methanol fraction-driven variations in fluid density and viscosity of up to 20 % and 30 %, respectively, as well as the relatively low diffusion coefficients compared to those of gases result in low mixing degrees of both liquid components. Structural geological features need to be considered in the selection of methanol storage sites, since these directly affect the spatial extent of the mixing region, and thus methanol recovery efficiency.

 

Kempka, T., Steding, S., Kühn, M. (2022) Verification of TRANSPORT Simulation Environment coupling with PHREEQC for reactive transport modelling. Advances in Geosciences, 58, 19-29. https://doi.org/10.5194/adgeo-58-19-2022

Kempka, T. (2020) Verification of a Python-based TRANsport Simulation Environment for density-driven fluid flow and coupled transport of heat and chemical species. Advances in Geosciences, 54, 67-77. https://doi.org/10.5194/adgeo-54-67-2020

Ma, J., Li, Q., Kempka, T., Kühn, M. (2019) Hydromechanical Response and Impact of Gas Mixing Behavior in Subsurface CH4 Storage with CO2-Based Cushion Gas Energy & Fuels 33 (7), 6527-6541. https://doi.org/10.1021/acs.energyfuels.9b00518

Oldenburg, C. M. (2003) Carbon Dioxide as Cushion Gas for Natural Gas Storage. Energy Fuels 17(1), 240−246. https://doi.org/10.1021/ef020162b

How to cite: Kempka, T.: Mixing behaviour of methanol stored in depleted hydrocarbon reservoirs to support the European Union energy transition, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9383, https://doi.org/10.5194/egusphere-egu23-9383, 2023.

One of the main challenges in soil science lies in the passage from heterogeneous soil structure to a quantified multi-scale 3D model. Here a new approach to quantify the microbial distribution relating to soil pore structure is presented. Characterising 3D microbial soil structural in digital porous media is not found and most soil process models tend to assume a homogenous spatial distribution of microbes. We measured the in situ spatial distribution of bacteria in arable soils across scales from sub-micrometers to metres and here we describe further progress to quantify and explicitly model the 3D microbial distributions, based on a stochastic Bayesian approach to predict spatial variation in the underlying bacterial intensity measure. A 3D higher order Multi-Markov chain model is introduced to model complex geometry of real soil structure and associated microbial distribution. In this study, Markov random fields are used to construct multiscale 3D Pore Architecture Models (PAM). The binary structure of PAM has been successfully used to predict multiphase flow behaviour in porous media such as hydrocarbon bearing reservoir rocks, we explore further to use such a new multi-components scheme in modelling pore structure incorporating with microbial spatial distribution, the multicomponent Markov chain model, which is a stationary multiple higher order Markov chain. The models parameterisation is based on high resolution SEM images of soil that have been prepared in a manner that preserves the microbial community information in situ. Based on the quantified 3D multiscale soil structure associated with microbial distribution components, the accurate reactive flow of microbial degradation can be simulated to predict environmental impact of microbial activates in the field. A variety of examples of structures and bacterial distribution created by the models are presented.

How to cite: Wu, K.: A new 3D multicomponent markov chain model incorporating multi-scale soil structure with microbial distribution, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9593, https://doi.org/10.5194/egusphere-egu23-9593, 2023.

EGU23-9686 | ECS | Orals | ERE1.9

Geologic Controls on the Genesis of the Arctic Permafrost and Sub-Permafrost Methane Hydrate-bearing System in the Beaufort–Mackenzie Delta 

Zhen Li, Elena Chabab, Erik Spangenberg, Judith Schicks, and Thomas Kempka

The Canadian Mackenzie Delta (MD) is a river-mouth depocentre and the second-largest Arctic delta. It exhibits high resources of prospected sub-permafrost gas hydrates (GHs), mainly consisting of thermogenic methane (CH4) at the Mallik site, which migrated from deep source rocks. The objective of the present study is to confirm the sub-permafrost GHs formation mechanism proposed by Li et al. (2022a), stating that CH4-rich fluids were vertically transported from deep overpressurized zones via geologic fault systems and formed the present-day GH deposits in the shallower Kugmallit Sequence since the Late Pleistocene. Given this hypothesis, the coastal permafrost began to form since the early Pleistocene sea-level retreat, steadily increasing in thickness until 1 Million years (Ma) ago. Observations from well-logs and seismic profiles were used to establish the first field-scale static geologic 3D model of the Mallik site. A framework of equations of state to simulate the formation of GHs and permafrost (Li et al., 2022a, 2022b) has been developed and coupled with a numerical simulator for fluid flow as well as the transport of chemical species and heat in previous studies. Here, numerical simulations using the proven thermo-hydro-chemical simulation framework were employed to provide insights into the hydrogeologic role of the regional fault systems in view of the CH4-rich fluid migration and the spatial extent of sub-permafrost GH accumulations during the past 1 Ma. The simulated ice-bearing permafrost and GH interval thicknesses, as well as sub-permafrost temperature profiles, are consistent with the respective field observations, confirming our previously introduced hypothesis. In addition, simulation results demonstrate that the permafrost has been substantially heated to 0.8–1.3 °C, triggered by the global temperature increase of about 0.44 °C (IPCC, 2022) and further accelerated by Arctic amplification from the early 1970s to the mid-2000s. Overall, the good agreement between simulations and observations demonstrates that the present modeling study provides a valid representation of the geologic controls driving the complex permafrost-GH deposit system. The model’s applicability for predicting GH deposits in permafrost settings can provide relevant contributions to future GH exploration and exploitation activities.

References

IPCC, 2022: Climate Change 2022: Impacts, Adaptation, and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [H.-O. Pörtner, D.C. Roberts, M. Tignor, E.S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke, V. Möller, A. Okem, B. Rama (eds.)]. Cambridge University Press. Cambridge University Press, Cambridge, UK and New York, NY, USA, 3056 pp., doi:10.1017/9781009325844.

Li, Z., Spangenberg, E., Schicks, J. M. & Kempka, T. Numerical Simulation of Coastal Sub-Permafrost Gas Hydrate Formation in the Mackenzie Delta, Canadian Arctic. Energies 15, 4986 (2022a). https://doi.org/10.3390/en15144986

Li, Z., Spangenberg, E., Schicks, J. M. & Kempka, T. Numerical Simulation of Hydrate Formation in the LArge-Scale Reservoir Simulator (LARS). Energies 15, 1974 (2022b). https://doi.org/10.3390/en15061974

 

How to cite: Li, Z., Chabab, E., Spangenberg, E., Schicks, J., and Kempka, T.: Geologic Controls on the Genesis of the Arctic Permafrost and Sub-Permafrost Methane Hydrate-bearing System in the Beaufort–Mackenzie Delta, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9686, https://doi.org/10.5194/egusphere-egu23-9686, 2023.

In the past decades, boreholes were drilled all over the world for the purpose of hydrocarbon prospection. Data from these boreholes are a very valuable resource, that can be used in current geological, geothermal and hydrogeological studies. Since the process of drilling is both expensive and disturbing to the environment the possibility of incorporating data that already exists in the current studies is always worth consideration. However, in the case of older boreholes quality of data is not on par with modern standards which limits its usefulness, especially in the case of data from boreholes drilled in thin-bedded rock formations.

Resistivity logs are one of the main logs used both in hydrocarbon prospection and other applications such as geological, geothermal and hydrogeological studies. Resistivity logs measured by older generations of logging tools are characterized by significantly lower vertical resolution in comparison to logs measured by newer logging tools which affect the quality of the interpretation. However, the information averaged in the process of logging can be partially restored in the process of iterative inversion.

The focus of the presentation is on the utilization of open-source global optimization software in the process of inversion of resistivity well logs. Since inverse problems encountered in geophysics tend to be on the difficult side, relatively simple optimization schemas that often can be found in open-source software are not always giving good results. Therefore, in the presentation, a few methods that allow adapting those algorithms to the problem of inversion of well logs are discussed. The performance of the inversion procedure is validated on synthetic data and real data from the borehole where resistivity logs were measured by different generations of logging tools in the same depth intervals, which allows for comparison of the inversion results to logs measured by modern equipment.

 

The research was funded by the National Science Centre, Poland, grant number 2020/37/N/ ST10/03230.

How to cite: Wilkosz, M.: Adaptation of open-source global optimization software to the process of iterative inversion of resistivity well logs, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10004, https://doi.org/10.5194/egusphere-egu23-10004, 2023.

EGU23-11350 | ECS | Orals | ERE1.9

New Insights into Underlying Mechanisms of CO2 Wettability and Residual Saturation from Laboratory Measurements of Multi-Phase Zeta Potential in Supercritical CO2-Rock-Brine Systems 

Miftah Hidayat, Jan Vinogradov, Mohammad Sarmadivaleh, Stefan Iglauer, David Vega-Maza, and Jos Derksen

Measurements of the zeta potential using streaming potential method are frequently used to characterise flows in subsurface settings owing to a broad range of applications of this petrophysical property; examples include CO2 geological storage, hydrocarbon reservoirs, geothermal sources and freshwater aquifers. Many experimental studies of the zeta potential have been carried out covering a wide range of parameters including different rock mineralogy, brine concentration and composition, and temperature to understand the impact of each parameter. The capability of the streaming potential method to be used on intact rock samples, single-/ and multi-phase flows, wide range of salinity, pressure and temperature makes the method suitable for representation of typical subsurface conditions. However, none of previous studies reported high multi-phase measurements at high pressure conditions typical for deep reservoirs. To adequately represent subsurface conditions of carbon geological storage sites, the minimum experimental pressure of 7.38 MPa and minimum temperature of 31 °C, consistent with the supercritical-CO2 (scCO2), need to be used. Obtaining stable measurements of the streaming potential under these conditions is extremely challenging. We report a detailed design of a high-pressure experimental system and experimental protocol for multi-phase streaming potential measurements that were carried out on scCO2-sandstone-brine systems at temperature of 40 °C, pressures ≤10 MPa and with a variety of aqueous solutions.

The obtained results demonstrate for the first time that the multi-phase zeta potential correlates with the measured scCO2 residual saturation and rock’s wetting state interpreted from other parameters. Moreover, our results unambiguously identify for the first time the polarity and likely magnitude of the scCO2-brine interfacial zeta potential. Our findings improve the current understanding of the complex wetting behaviour of scCO2 and provide important experimental data for numerical (surface complexation, molecular dynamics), analytical (DLVO) or combined models.

How to cite: Hidayat, M., Vinogradov, J., Sarmadivaleh, M., Iglauer, S., Vega-Maza, D., and Derksen, J.: New Insights into Underlying Mechanisms of CO2 Wettability and Residual Saturation from Laboratory Measurements of Multi-Phase Zeta Potential in Supercritical CO2-Rock-Brine Systems, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11350, https://doi.org/10.5194/egusphere-egu23-11350, 2023.

Inland salinisation due to the upwelling of highly mineralised deep waters formed by leaching of Upper Permian salt diapirs is a typical phenomenon in the North German Basin. In the German State of Brandenburg, the local absence of the regionally most important aquiclude, the Lower Oligocene Rupelian Clay, separating deep saline waters from the overlying freshwater aquifers, is considered to be the main cause of local salinisation in the freshwater column.

The present study uses density-driven 3D flow and transport simulations to assess saltwater upwelling across Quaternary window sediments in the Rupelian for an area in southeastern Brandenburg with detectable salt concentrations in the freshwater column. Previous simulations along a 55 km long transect in Brandenburg using a 2D model have already demonstrated the potential negative impact of groundwater extraction, the use of the deep subsurface as a storage reservoir or lower precipitation rates and decreasing groundwater levels as a consequence of global climate change on the degree of upper aquifer salinisation (Chabab et al., 2022; Tillner et al., 2016; Wetzel et al., 2016).

The presented simulation results show that 3D flow strongly affects the temporal and spatial distribution of upper aquifer salinisation due to the varying extent of layers and erosion windows in the Rupelian Clay. The location of groundwater extraction sites, hydraulically conductive faults and spatial variations in groundwater recharge additionally influence the location and degree of shallow aquifer salinisation, and must therefore be carefully considered. Depending on topographic gradients and density variations occurring due to differences in pressure and temperature, convective cells with descending flow and freshwater lenses in the saltwater column also develop locally. We show that 3D flow simulations are essential for site-specific analysis to represent the dynamics of the system with many different hydrogeologic interacting and controlling factors.

 

Literature

Chabab, E., Kühn, M., Kempka, T. (2022): Upwelling mechanisms of deep saline waters via Quaternary erosion windows considering varying hydrogeological boundary conditions. Advances in Geosciences, 58, 47-54.

Tillner, E., Wetzel, M., Kempka, T., Kühn, M. (2016): Fault damage zone volume and initial salinity distribution determine intensity of shallow aquifer salinisation in subsurface storage. Hydrology and Earth System Sciences, 20, 1049-1067.

Wetzel, M., Kühn, M. (2016): Salinization of Freshwater Aquifers Due to Subsurface Fluid Injection Quantified by Species Transport Simulations. Energy Procedia, 97, 411-418.

How to cite: Chabab, E., Kühn, M., and Kempka, T.: Saltwater upwelling quantified by density-driven 3D flow and transport simulations for a study area in Brandenburg, Germany, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12741, https://doi.org/10.5194/egusphere-egu23-12741, 2023.

EGU23-12843 | ECS | Posters on site | ERE1.9

Coupling approach in shallow, unconfined aquifers in the Po Plain area: A preliminary study for future ground monitoring purposes. 

Celine Eid, Christoforos Benetatos, and Vera Rocca

The use of the coupling approach in analyzing the interaction between the flow field and the stress field in shallow, unconsolidated aquifers allows a better description of the involved phenomena. We perform our study on an area in the Po Plain (northern Italy) in the province of Bologna in Emilia-Romagna based on intended future studies on ground movements due to the superposition of shallow water production with deep underground gas storage.

The static geological model of the alluvial sediments, locally exceeding 500 meters of thickness, is developed via a stochastic approach in order to manage the high degree of uncertainty in the system spatial continuity and heterogeneities. Corresponding water production data and piezometric measurements are collected for simulating the dynamic behavior of the shallow aquifer. The high uncertainty in water production data are managed considering a maximum and minimum scenarios on the basis of punctual well measurements and regional trend information. Correlation law between petrophysical parameters and deformation variables are derived for technical literature. The coupling technique is then applied and some sensitivity analysis are developed to assess the effects of the correlation laws. The results are finally compared with the output from the uncoupled techniques.

How to cite: Eid, C., Benetatos, C., and Rocca, V.: Coupling approach in shallow, unconfined aquifers in the Po Plain area: A preliminary study for future ground monitoring purposes., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12843, https://doi.org/10.5194/egusphere-egu23-12843, 2023.

The decarbonization of communities and their energy supply is considered as a contemporary priority path forward, although it poses many challenges. In this scenario, geothermal energy can cover a pivotal role in the energy transition and in a wider spread of renewable energies. Moreover, the possibility to reuse or modifying existing wells for geothermal purposes is becoming a hot and promising topic. In Italy, there are more than 8000 abandoned/inactive on-shore wells drilled for hydrocarbon exploration subsequently abandoned either for the end of the resource (exhausted well) or for sterility (barren well). This can represent a huge opportunity for geothermal energy exploitation. The drilled borehole available data, collected during the exploration activity, provide useful information about the sub-surface reservoirs, highly reducing the mining risk level, and allowing direct and low cost access to the sub-surface heat energy.

This work aims to analyse the feasibility of the retrofitting of abandoned oil and gas wells focusing on the Italian territory, proposing a selection methodology of wells starting from raw data collection. We want to evaluate which could be the best technical solutions for the retrofitting of an inactive oil&gas well considering the closed loop geothermal options, both coaxial and deep-U heat exchangers options. We decided to concentrate on the closed loop solution for the retrofitting because of its low environmental impact due to the absence of fluid exchange with the surrounding underground, despite the lower efficiency, compared to a system that involves the extraction of fluids from the subsoil.

A database, that collects data of wells drilled since the middle of 1900, provide by public information, is used, applying a first filter by considering the following discriminant parameters: the depth (more than 1000 m), the Bottom Hole Temperature (BHT), higher than 65°C, and the nearness of possible end-users. After this operation a set of 541 wells has been obtained.  A focus on the status of the well has been performed,  such as vertical or deviated and the availability of a litho-stratigraphic data to thermally characterize the rock formations around the well.  Then, the measured temperature data was analysed to figure out the distribution of geothermal gradient and to identify different situations in terms of temperature at national scale, that could be selected later as representative case studies of high, medium and low enthalpy geothermal plant.  Moreover, the Horner plot approach have been adopted for computing equilibrium temperature at depth after drilling, obtaining the real temperatures for each well. The proximity to possible heat stakeholders was then assessed using a GIS system.

How to cite: Facci, M., Di Sipio, E., and Galgaro, A.: Energy transition and Deep Geothermal solution role: a screening procedure for the retrofitting and reuse of ex Oil&Gas wells as deep closed-loop borehole heat exchangers in Italy, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14599, https://doi.org/10.5194/egusphere-egu23-14599, 2023.

EGU23-15410 | Posters on site | ERE1.9

Sparse image domain wavefield tomography for low-cost CCS monitoring in repurposed hydrocarbon fields 

Sjoerd de Ridder, Afsaneh Mohammadzaheri, Alexander Calvert, and Mikael Lüthje

Seismic time-lapse (4D) imaging has been considered as a key solution to monitor CO2 reservoirs. However, traditionally this technology requires dense data acquisition to produce high-resolution images. It is anticipated that monitoring will be required for more than 50 years after CCS operations cease and the monitoring phase is profit-negative. Developing cheaper 4D seismic imaging techniques is necessary. Historical knowledge of the subsurface structure in and near abandoned hydrocarbon fields, could reduce the dense data requirement of 4D imaging.

Here we present preliminary results of 4D seismic (image-domain) wavefield tomography (IDWT) using pre-stack gathers from a sparse monitoring acquisition. IDWT uses short-offset data to exploit primarily kinematic changes rather than amplitude changes. IDWT minimises the shift between baseline and monitor migrations by optimising the monitor velocity model. Pre-stack IDWT, unlike post-stack methods, can use individual shot gathers to calculate the migration images. This property is beneficial when using sparse data acquisition permitting reliable measurement of shifts between monitor and baseline. Knowing the structure of the subsurface, we can design sparse acquisition surveys for seismic deployment, to minimize uncertainty in target areas. 

We create synthetic models based on Tyra gas field, a prospective future repository of CO2 in the Danish sector of North Sea and simulate CCS and subsequent leakage scenarios. The presence of CO2 in the reservoir, as well as the effect of reservoir pressure on the overburden stress-state, changes the seismic velocity structure of the reservoir and the overburden. These velocity changes cause an apparent depth (or time) shift when migrating the data.

How to cite: de Ridder, S., Mohammadzaheri, A., Calvert, A., and Lüthje, M.: Sparse image domain wavefield tomography for low-cost CCS monitoring in repurposed hydrocarbon fields, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15410, https://doi.org/10.5194/egusphere-egu23-15410, 2023.

Coaxial Deep Borehole Heat Exchanger (DBHE) provides an alternative way to extract geothermal energy by circulating a working fluid without producing geofluids or performing injection processes. It can be used to avoid induced seismicity issues caused by injection operations in hydrothermal doublets or to repurpose damaged or non-productive wells. A detailed numerical model is required to accurately capture as well the thermo-hydraulic processes within the DBHE and the cooling effects in the surrounding reservoir. This numerical model is often high dimensional. For a real-time monitoring purpose and optimization study, a direct numerical simulation with this model is computationally intractable.

In this study, we use a physics-based machine learning method to reduce the computational cost of the performed forward model run. The physics-based machine learning method here is based on the non-intrusive reduced-basis method which expresses a physical solution in a linear combination of basis functions and weights. It is a model-order reduction technique that is mathematically proven to produce physically consistent predictions. The structure of the physics is maintained in basis functions and a machine learning model is deployed to calculate the weight for each basis function.

We show the advantages of using the physics-based machine learning method by applying it to the planned coaxial DBHE in Eden (Cornwall, UK). The forward simulation is performed using the open-source simulator GOLEM, a finite-element (FE) based simulator that is built within the MOOSE framework. In this study we provide a running time comparison between the FE simulations and the physics-based machine learning simulations. We will also evaluate the accuracy of the physics-based machine learning predictions towards the FE solutions. Here, we would like to emphasize the significant computational speed-up that allow us to obtain new temperature and pressure state predictions in real-time context and to perform optimization with numerous iterations.

How to cite: Teza, D., Santoso, R., Koltzer, N., Degen, D., Bennett, T., and Wellmann, F.: Physics-based machine learning for modeling thermo-hydraulic processes in a coaxial deep borehole heat exchanger, considering an explicit reservoir-wellbore representation: A case study of Cornwall, UK , EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16369, https://doi.org/10.5194/egusphere-egu23-16369, 2023.

EGU23-16627 | Posters on site | ERE1.9

CCS Reservoir Characterisation using Carbon Quantum Dots 

Paul Glover

Efficient use of new CCS resources depends critically on their characterisation. This is as true for CCS reservoirs that are deep aquifers or reservoirs that have previously been exploited as oil or gas reservoirs. Conventional pre-existing or newly commissioned reservoir characterization methodologies, such as well logs, 3D and 4D seismic reflection and cross-well electromagnetic imaging are limited in their scope and resolution. For CCS, the  crucial characterisation is that of the connectivity of the pore network. Carbon quantum dots (CQDs) are inert carbon nano-particles less than 10 nm in diameter. They can be made easily from environmentally-friendly stock materials and remain stable in aqueous solution no matter the pH or salinity, unlike conventional nanoparticles. In fluorescence spectroscopy CQDs demonstrate a strong absorption in the UV region with peaks at 228 nm and 278 nm. Their fluorescence spectra occupy the visible spectrum and are related to the stimulating frequency. These optical properties allow the number of particles to be ascertained easily and their small size allows them to be pervasive in the porous medium. Consequently, CQDs are ideal for use as a conservative tracer. Core and bead–pack tests have shown that almost 100% of the injected CQDs can be recovered from the porous medium indicating that there would be no damage to the CCS resource by their use. Breakthrough curves (BTCs) can be used to calculate the porosity and connectivity of water saturated rocks and the water saturation and connectivity of rocks from previously exploited hydrocarbon reservoirs at temperatures up to 80oC. Indeed it is possible that CQDs could be used to monitor quantitatively the emplacement of CO2 along the injection path. Although these CQDs have an attenuated performance in carbonate rocks, surface coatings are expected to resolve this question. Surface functionalisation will also allow the properties of the reservoir, such as temperature to be measured by altering the frequency of the emerging CQDs.

How to cite: Glover, P.: CCS Reservoir Characterisation using Carbon Quantum Dots, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16627, https://doi.org/10.5194/egusphere-egu23-16627, 2023.

EGU23-16672 | Posters on site | ERE1.9

Unconventional Fractal Modelling and Simulation of Heterogeneous and Anisotropic Reservoirs 

Paul Glover, Mehdi Yaghoobpour, Piroska Lorinczi, Wei Wei, Li Bo, and Saddam Sinan

One strategy for reducing global greenhouse gas emissions as the world progresses towards net zero is to extract more hydrocarbons from existing resources. Conventional modelling and simulation of heterogeneous and anisotropic reservoirs consistently and significantly underestimates production, sometimes by as much as 70%.

We now understand that many reservoir properties are fractal, such as porosity, grain size and permeability. While water saturation and capillary pressure have distributions which arise from fractally-distributed microstructural properties. Recent work has resulted in the development of the fractal theory of Archie’s laws, providing fractal dimensions underlying both the cementation and saturation exponents that is consistent with the n-phase Archie’s law theory.

The significant underestimation of production by conventional reservoir models can be overcome by the use of advanced fractal reservoir models (AFRMs) which take account of the fractal distribution of key petrophysical properties such as porosity, grain size, cementation exponent, permeability, water saturation and capillary pressure. These models employ existing and interpolated data across an extended range of scales and take account of variability less than the 50 m seismic resolution limit. AFRMs provide production profiles that are much closer to actual production profiles.

This presentation describes briefly the AFRM approach to the modelling and simulation of heterogeneous and anisotropic reservoirs, showing how AFRMs can be generated easily to match an imposed degree of heterogeneity and anisotropy, or can be conditioned to represent the heterogeneity and anisotropy of the target reservoirs. We describe how AFRMs can be generated and normalised to represent key petrophysical parameters, how AFRM models can be used to calculate permeability, synthetic poroperm cross-plots, water saturation maps and relative permeability curves, and how AFRMs which have been conditioned to represent real reservoirs provide a much better simulated production parameters than the current best technology.

Generic AFRM modelling and simulation show that total production, production rate, water cut and the time to water breakthrough all depend strongly on heterogeneity and anisotropy. Counter to expectation, optimal production is obtained from placing both injectors and producers in the most permeable areas of heterogeneous reservoirs. Furthermore, modelling with different degrees and directions of anisotropy shows how hydrocarbon production depends critically on anisotropy direction, which changes over the lifetime of the reservoir.

AFRMs are ultimately only useful if they can be conditioned to real reservoirs. We have developed a method of fractal interpolation to match AFRMs to reservoir data across a wide scale range. Results comparing the hydrocarbon production characteristics of such an approach to a conventional krigging approach show a remarkable improvement in the modelling of hydrocarbon production when AFRMs are used; with AFRMs in moderate and high heterogeneity reservoirs returning values always within 5% of the reference case, while the conventional approach often resulted in systematic underestimations of production rate by over 70%.

Although more work needs to be done on this new approach to reservoir modelling, initial results indicate that it has the potential for improving the accuracy of modelling and simulation in heterogeneous and anisotropic reservoirs by an order of magnitude or more.

How to cite: Glover, P., Yaghoobpour, M., Lorinczi, P., Wei, W., Bo, L., and Sinan, S.: Unconventional Fractal Modelling and Simulation of Heterogeneous and Anisotropic Reservoirs, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16672, https://doi.org/10.5194/egusphere-egu23-16672, 2023.

EGU23-17292 | Posters on site | ERE1.9

Molecular simulation of stripping of crude oil by CO2 in tight reservoirs 

Qian Wang, Jian Shen, Bai Jie, Paul W.J. Glover, and Piroska Lorinczi

Tight oil reservoirs are often oil-wet and contain surface adsorbed layers of hydrocarbon. Improvement of production lies in part in the ability to produce this adsorbed oil for its own sake and to unblock small pores that can improve the relative permeability of the reservoir. In this paper we have used molecular modelling and simulation first to study the formation of adsorbed oil films made from n-alkanes of 5 different molecular weights (nC7, nC12, nC18, nC22, nC25) on an hydroxylated ->-SiO2 surface, and then to examine the process of stripping oil from these layers using carbon dioxide, nitrogen and water. It was found that all n-alkanes but nC12 formed a monolayer oil film, while nC12 formed a three-layer oil film. Molecular weight, length and flexibility of the n-alkane were all factors in oil film formation. It was found that flooding with CO2 is able to strip all of the modelled n-alkanes from the α-SiO2 surface effectively. The time required to strip the n-alkane was longer for n-alkanes with higher molecular weights. The stripping process was divided into three stages: (i) CO2 diffusion and dissolution, (ii) competitive adsorption, and (iii) oil film push-off. A fourth stage was recognized only for light n-alkanes, and which involved the dissolution of CO2 in mobilized n-alkane, leading to improvements in its mobility. Comparative simulations using nC12 showed that N2 and H2O exhibit no efficacy in stripping n-alkanes from surface adsorbed oil films. The efficacy of CO2 was attributed to (i) it being a polar molecule that is attracted to the hydroxylated silica surface, (ii) its miscibility in n-alkanes, and (iii) that it is in a supercritical state at reservoir conditions. The failure of N2 arises because it is a non-polar molecule with no affinity for the surface and exists as an immiscible gas at reservoir conditions. Water was ineffective, because, though polar, it is immiscible in the oil layer and so cannot access the rock surface. Consequently, CO2-flooding is expected to be particularly effective in improving production from tight oil-wet clastic reservoirs.

Key words: tight reservoir; pore throats; CO2 flooding; oil film stripping; molecular simulation

How to cite: Wang, Q., Shen, J., Jie, B., Glover, P. W. J., and Lorinczi, P.: Molecular simulation of stripping of crude oil by CO2 in tight reservoirs, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17292, https://doi.org/10.5194/egusphere-egu23-17292, 2023.

Underground coal fire (UCF) is a disaster associated with coal mining activities which occurs in almost all main coal-producing countries. UCF not only burns up massive coal resource, but also causes damages and pollutions to local eco-environment, such as the land subsidence, the contamination to soil and nearby water resource, the pollution to air, and so on. In this presentation, the author attempts to illustrate a comprehensive understanding to UCF from micro and macro perspectives, including the mechanism of UCF occurrence and propagation, the monitoring and early warning of UCF, the efficient advanced materials depressed the UCF and the UCF’s impact on local eco-environment, which is helpful to understanding well of UCF. Methods and technologies which were employed in this study include analyses of the remote sensing data, the TG data, the C13- NMR data, the HRTEM data, the FTIR data, the XRD and XPS data, etc. Necessary models for quantifying UCF occurrence and propagation were established by analyzing the process of UCF. And a novel method was proposed by analyzing the distribution of surface temperature coupled with the NDVI data and InSar data. Some inhibitors were used in this study to depress the proceeds of coal oxidation which is useful to control the UCF. In addition, considering the UCF’s impacts on local eco-environment, coal-fire-induced heavy metal contamination to soil also were investigated which show that the heat effect is a major factor influences the distribution of heavy metal. Finally, strategies were suggested to carry out the restoration of UCF sites after it was extinguished.

Keywords: Underground Coal Fire; Mechanism of Occurring and Propagating; Remote Sensing; Inhibitor; Eco-environment Impact

How to cite: Zeng, Q.: Causes, Monitoring, Extinction, and Eco-environmental Impacts of Underground Coal Fires: A Comprehensive Perspective, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-914, https://doi.org/10.5194/egusphere-egu23-914, 2023.

EGU23-1643 | Orals | ERE1.12

Underground coal fires – A global post-mining catastrophe 

Robert Finkelman and Henry Dodds

Uncontrolled coal fires are a universal coal mining and post-mining concern. Efforts to extinguish these fires are often unsuccessful and these fires can result in major catastrophes such as the abandonment of the town of Centralia Pennsylvania in the U.S. and displacement of many thousands of villagers in India. The physical threat of these fires, often a result of coal mining, is a serious issue that has taken the lives of people in the U.S., Asia, and Africa. However, an equally though more insidious issue is the long-term health impacts of the emissions of these uncontrolled coal fires. Recent studies in the Jharia region of India has shown that villagers living about one mile from active coal fires reported twice as many health concerns as villagers living about five miles away. Yet, there are many villages in this region and elsewhere where people are living in immediate proximity to these fires. Studies of the gases emitted from these fires and condensates formed from the escaping gases document the mobilization of potentially toxic gases such as benzene, xylene, toluene, methane, carbon monoxide and elements such as As, Se, Hg, F, Pb, Sb. An SEM/EDX study of a small (30mm X 20mm) piece of condensate collected from an active underground coal fire just meters from a village revealed several generations of deposition with at least 30 phases containing ammonia, B, F, Al, Si, S, Cl, Fe, Cu, Zn, As, Se, Br, Mo, Cd, I, Ba, Pb, and Bi. Clearly, more attention should be paid to this post mining catastrophe to minimize the health problems and deaths resulting from these uncontrolled coal fires.

How to cite: Finkelman, R. and Dodds, H.: Underground coal fires – A global post-mining catastrophe, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1643, https://doi.org/10.5194/egusphere-egu23-1643, 2023.

EGU23-1693 | Posters on site | ERE1.12

Spatial Assessment of Asbestos Mine Remediation Effect Using Airborne Hyperspectral Imaging System 

Yongsik Jeong, Jaehyung Yu, Lei Wang, and Hyun-Cheol Kim

This work investigated an abandoned asbestos mine (AAM) remediation project in CA, US. Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) hyperspectral data were used to assess the mine treatment effect. The distribution of AAM and restored area were evaluated before and after remediating based on the spectral analysis and model for indicating naturally occurring asbestos (NOA) and encapsulation (remediation). We developed NOA, host rock, and encapsulation indices by binary logistic regression modeling using hyperspectral bands. The detection models statistically selected visible-near infrared (VNIR) regions rather than shortwave infrared (SWIR) ranges. The models-based classification accuracy was approximately 84%. Notably, the detection accuracy of non-treated and treated areas was increased to about 90% excluding the host rock index. The NOA and encapsulation indices showed that they can be efficiently applied to asbestos occurrence/remediation. The remote sensing data revealed that the whole AAM area was increased by ~5% by the remediation process, and the restoration activity reduced asbestos exposure by ~32%. This work would be contributed to providing an intuitive and realistic-spatial understanding of the planning and managing remediation project.

How to cite: Jeong, Y., Yu, J., Wang, L., and Kim, H.-C.: Spatial Assessment of Asbestos Mine Remediation Effect Using Airborne Hyperspectral Imaging System, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1693, https://doi.org/10.5194/egusphere-egu23-1693, 2023.

Modelling oxygen-limited and self-sustained smoldering propagation is of significance for prevention of underground coal fire hazards. However, coupling oxidative reaction and oxygen transport in multi-scale porous media has been still a challenging issue and the conventional models have been questioned by inadequacy of TG-scale kinetic parameters applied to bed-scale propagation. In this work, an analytic expression of oxidative reaction rates limited by oxygen transport was derived from the conservation equations of oxygen species transport in gas and solid. Along with the Darcy air flow driven by thermal buoyancy, the oxygen-limited and self-sustained smoldering propagation of underground coal fires was modeled in this work. The model was compared with laboratory experiments and the conventional model. Results show that the proposed model well predicts the oxygen-limited and self-sustained smoldering propagations of underground bituminous and anthracite coal fires. The predictability of the proposed model is better than the conventional model in spite of great effort to modify kinetic parameters best fitting with experimental data. It is validated that the proposed model addresses the two puzzled issues in the conventional model with respect to buoyancy-driven, oxygen-limited, and self-sustained smoldering propagation of underground coal fires. This work may help to develop green countermeasures to mitigate underground coal smoldering fires.

How to cite: Song, Z.: Modelling oxygen-limited and self-sustained smoldering propagation of underground coal fires driven by thermal buoyancy, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1959, https://doi.org/10.5194/egusphere-egu23-1959, 2023.

In the coal fire control project, the multiple water injections used to extinguish coal fires and the coal fires that reignite can cause many forms of ground collapse to occur, threatening project safety. Therefore, studying the thermal damage and capturing disaster signals of sandstone, a main weight bearer in coal measure strata, exposed to heating-cooling, cycles is critical to ensure the engineering safety. In this work, the coal-measure sandstones from Urumqi, Xinjiang and Yulin, Shaanxi, China, were collected. For the sandstones from Urumqi, China (Type A sandstone), the samples were first heated to 800 °C, and cooled using water, heated to a setting temperature (100 °C, 200 °C, 300 °C, 400 °C, 500 °C, 600 °C, 700 °C and 800 °C), and cooled using water again. The ultrasonic p-wave velocity, density and water absorption of the sandstones were tested. Uniaxial compression tests and shear tests were conducted on the sandstones. The thermal damage in sandstones were analysed using rock energy theory. For the sandstones from Yulin, China (Type B sandstone), the X-ray diffraction test, scanning electron microscope test and uniaxial compression experiment with AE monitoring were carried out for the raw sandstone and the sandstone exposed to 800 °C and water cooling twice (cooling shock sandstone), respectively. The results show that, for the type A sandstone, compared with the mechanical strength of the sandstone at room temperature, the mechanical strength of the sandstone exposed to 800 °C for the first time is decreased by less than 20%. When the sandstone is exposed to high temperature again, the critical threshold temperature is 400 °C. When the temperature exceeds 400 °C, the thermal damage aggravated again and the mechanical strength rapidly degraded. For the type B sandstone, the results showed that the crack density and volume of cooling shock sandstone increased by 8.79% and 2.69%, respectively, and p-wave velocity decreased by 51.83%, compared with those of the raw sandstone. The mechanical strength of cooling shock sandstone decreased, including a 50.68% reduction in elastic modulus. The AE attenuation coefficient α=(1-Ec/E0) /kc, related to the elastic modulus and the crack change rate, was derived, which providing an approach to count the attenuation of AE signal caused by thermal damage for cooling shock sandstone. Increasing the preamplifier amplification factor is feasible to improve the accuracy for monitoring the fracture of cooling shock sandstone in coal-fire control project.

How to cite: Ge, S., Shi, B., Zhang, S., Deng, J., and Wu, C.: Effect of thermal damage on capturing fracture signal of high temperature sandstone subjected to cooling shock from the coal fire control project, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3848, https://doi.org/10.5194/egusphere-egu23-3848, 2023.

EGU23-4239 | Orals | ERE1.12

residual space distribution law in long-wall old mining  area 

Zhi Guo, Wei Lu, Yongqiang Zhou, Meng Zhang, Changlong Liao, and Changxiang wang

Grouting treatment in old goafs is an effective method to achieve sustainable development of mining areas after coal seam mining. Due to the concealment of the old goaf and the lack of historical information, it is difficult to directly obtain the distribution of the residual void in the old goaf. In this study, the residual void distribution law of the longwall old goaf area was studied through similar material simulation test, gangue compression test and stress arch theory. The results showed that the collapse zone can be divided into regular collapse zone and irregular collapse zone. Fissure zone and regular collapse zone have few grouting voids due to the closing effect. Due to the different forms of crushing, the irregular collapse zone has large voids and was difficult to completely close with the passage of time, which is the key area of grouting treatment. For the longwall old goaf area that has reached full mining, the stress relief zone was formed at both ends of the open-off cut and the stop-mining line, and the stress recovery zone and the stress stabilization zone were formed in turn close to the middle of the goaf area. The evolution process of stress arch and fracture arch in the stope can be divided into two stages and three periods. The first stage: the development stage of fracture arch and stress arch, that is, the stress relief and stress recovery period of broken gangue in the goaf. The second stage: the fracture arch and stress arch formation stage, that is, the stress stabilization period of broken gangue in the goaf area. On the basis of the above research, the concept of residual void equivalent height was proposed, and its calculation formula was given, and furthermore, the formula for the estimation of grouting volume was given. The height of the irregular collapse zone was 0.915~0.975 times of the coal seam mining thickness, the residual void equivalent height was about 0.3 times the mining thickness (take its upper limit value), and the residual void equivalent height in insufficiently collapsed area was 0.5 times the mining thickness.

How to cite: Guo, Z., Lu, W., Zhou, Y., Zhang, M., Liao, C., and wang, C.: residual space distribution law in long-wall old mining  area, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4239, https://doi.org/10.5194/egusphere-egu23-4239, 2023.

Abstract: Atmospheric pressure fluctuation is one of the most important factors affecting the climate environment and gas emission in the fire area. In order to obtain the influence rule of the surface atmospheric pressure change on the gas sampling and abnormal emission in the mine closed goaf, the No. 1 coal mine in Dananhu, Xinjiang was taken as the research object. Using Fourier transform and Fisher harmonic analysis and other methods, the influence of the periodic variation of atmospheric pressure on the gas leakage and outflow in the closed goaf was studied. The results showed that there were three atmospheric pressure periods of 15.2d, 1d and 182.2d, and the probability was greater than 95%. The time period with the highest number of atmospheric pressure peaks was 7:00-8:00, which accounted for 20.2% of total occurrence number in a day. And the time periods with the highest number of atmospheric pressure trough were 2:00, 15:00 and 16:00, accounting for 27.4%. The peak-to-trough transition time was mainly concentrated around 6h, and the diurnal variation curve of atmospheric pressure was mainly bimodal. The atmospheric pressure change rate was mostly concentrated in 10~50 Pa/h. It was determined that the distance that the gas sampling pipe was pre-laid into the inner side of the closed wall should be greater than 44.4m, and the CO concentration and atmospheric pressure in the closed goaf were both periodic and negative with atmospheric pressure. The research results have important guiding significance for the disaster warning and environmental protection of the goaf.

How to cite: Shao, Z. and Tan, B.: Research on the effect of periodic wide atmospheric pressure change on CO emission in closed goaf, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4676, https://doi.org/10.5194/egusphere-egu23-4676, 2023.

The coal-fire gases are the main actors in terms of element and heat transfer within burning post-mining waste heaps (BPWHs). Although they mainly comprise CO2 and water, they can locally be enriched in dimethyl (di)sulfide (as much as 15000 ppm, Bytom site), thiophene, SO2, H2S; 1,1- and 1,2-dichloroethane, dichloromethane and other halocarbons; chlorobenzene, ammonia, pyridine, HCN, numerous NOx, (iso)cyanogen halides, and triazine-based and imine-type compounds, AsH3, PH3, SiF4, and SF6, to mention some. Metals are most likely transported as neutral hydroxides, and/or carbonyl, nitrosyl, and hydride complexes, while iodine - as I2, iodosomethane, iodocyanoacetylene, and - alongside with Br and Cl - as halocarbons. Occurrence of exotic gases is possible considering their transient nature. The most recent proposal compounds include HNC, formaldoxime isocyanate, peroxyethyl nitrate; tetrafluoro-p-xylylene, perfluorinated p-benzyne, CHClF, HCFBr, 1,2,4-trixolane, thioacetaldehyde, thiocarbonyl fluoride, bromomethane, dithio-p-benzoquinone, monomethylsilane, and titanacyclopropene (e.g., Kruszewski, 2021). Still, the image of the coal-fire exhalative processes is not full. Here, crystal chemistry of some major minerals deposited within exhalative vents of the Upper Silesian Coal Basin heaps is presented. Chemistry of godovikovite - the major component of the Czerwionka-Leszczyny sulfate crust - is [(NH4)0.94K0.04Ca0.01Mg0.01]Σ1.00(Al0.90Fe0.09Ti0.01)Σ1.00[(SO4)1.99 (n=24); it thus bears 8 mol% sabieite and 3% steklite end-members. The local sabieite's formula is [(NH4)0.96K0.03Mg0.01]Σ1.00(Fe0.58Al0.40Ti0.02)Σ1.00(SO4)2.00. Chemistry of millosevichite from sulfate crust of Radlin is expressed as  (Al1.73Fe0.19Ca0.07K0.02Na0.01Mg0.01Ti0.01)Σ2.04[(SO4)2.97(PO4)0.01]Σ2.98 (n=16), while that for its minor Fe-analogue mikasaite is (Fe1.38Al0.51K0.04Ca0.03Ti0.02Na0.02)Σ2.00[(SO4)2.90(PO4)0.02]Σ2.92 (n=3). The local dolerophanite is likely stabilized by iron: (Cu1.96Fe0.03)Σ1.99O1.03(SO4)0.98 (n=15). Locally, a Fe-rich variety is observed, its chemistry being, possibly, (Cu1.26Fe0.65Na0.04K0.03Al0.02)Σ2.00[(SO4)0.95(SiO4)0.01]Σ0.96(O0.99Cl0.01)Σ1.00 (n=5). Dolerophanite is associated with honey-yellow crystals with the (Cu3.85Fe0.15)Σ3.00O1.33(SeO3)0.96(SO4)1.93 (n=6) formula, likely representing a new mineral species. So is true for a Cu-I-S species and a iodobismuthate (known both at Radlin and Rydułtowy), the forming abundant inclusions in extremely (Br,I)-enriched salammoniac. The wealth of the heap's exhalative zones is "completed" by (NH4)3XCl5 (X = Zn, Fe, Mg, Mn, Cu), a sodium thiosulfate pentahydrate, a potassium sodium dithionate chloride, an ammonium sulfate nitrate, and a phosphimate (tetra-μ-imidocyclotetraphosphate). Both the above halogen-bearing gaseous species and minerals result from transformation of the pore-contained post-mining brines.

Kruszewski, Ł., 2021. Burning Coal-Mining Heaps as an Organochemical Laboratory: Interesting Trace Compounds and Their Potential Sources.  Chapter 3, in: Organic Compounds, Las Vegas, Nevada, USA, ISBN: 978-93-87500-41-9, 38 pp., openaccessebooks.com/organic-compounds.html

How to cite: Kruszewski, Ł.: Gas-phase element transfer, rare mineral deposition, and other exhalative phenomena associated with coal fires in heaps: the state of art based on the data from the Upper Silesian Coal Basin, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6008, https://doi.org/10.5194/egusphere-egu23-6008, 2023.

EGU23-6557 | ECS | Posters virtual | ERE1.12

Semi-enclosed experimental system for coal spontaneous combustion for determining regional distribution of high-temperature zone of coal fire. 

Jingyu zhao, Hanqi Ming, Shiping Lu, Xiaocheng Yang, Yueyan Xiao, Xinrong Jiang, and Rui Li

Temperature variation and gas generation at different depths and positions in the coal combustion process were studied to determine the propagation and evolution of high temperature regions in the process of coal spontaneous combustion. This study selected coal samples from Mengcun, Shaanxi Province, People’s Republic of China, and developed a semi-enclosed experimental system (furnace) for simulating coal combustion. The thermal mass loss of coal samples under various heating rates (5, 10, and 15 °C/min) was analyzed through thermogravimetric analysis, and the dynamic characteristics of the coal samples were analyzed; the reliability of the semi-enclosed experimental system was verified through the equal proportional method of fuzzy response. The results revealed that the high-temperature zone was distributed nonlinearly from the middle to the front end of the furnace, and the temperatures of points in this zone decreased gradually as the layer depth increased. The apparent activation energy of the coal samples during combustion first increased and then decreased as the conversion degree increased. Furthermore, the proportion of mass loss and the mass loss rate in the coal samples observed in the thermogravimetric experiment was consistent with that observed in the first and second stages of the experiment conducted using the semi-enclosed system. The research findings can provide a theoretical basis for the prevention and control of high-temperature zones in coal combustion.

How to cite: zhao, J., Ming, H., Lu, S., Yang, X., Xiao, Y., Jiang, X., and Li, R.: Semi-enclosed experimental system for coal spontaneous combustion for determining regional distribution of high-temperature zone of coal fire., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6557, https://doi.org/10.5194/egusphere-egu23-6557, 2023.

Exploitation of coal mining is an important part for economic development, but the exploitation of coal mining will bring a serious impact on the local ecological environment. Ecological restoration is an effective method to improve the ecological environment in the mining areas. The first step of ecological restoration in post-mine is  to rebuild a sustainable mine-soil system. Fine soil overburden is often used in reconstructing soil profiles to provide habitat for vegetation restoration. Fine soil overburden will change the infiltration and evaporation of soil water. However, the understanding of the infiltration and evaporation of soil water is still an ongoing challenge. In this study, four groups of clay soil thicknesses (25 cm, 20 cm, 15 cm and 10 cm) were set up to simulate the overburden fine soil in post-mine ecological restoration, to study the influence of cover fine soil thickness on soil water infiltration and evaporation. The results showed that: a) the correlation between cover clay soil thickness and wetting front migration velocity was negative, namely, the thicker the cover clay soil thickness, the slower the wetting front migration velocity, and the smaller the average infiltration velocity is. However, the amount of water holding in thick overburden clay soil was more than the thin overburden clay soil. b) The overlying clay soil would improve soil water evaporation, but it wasn’t significant(p>0.1) with the thickness. The amount of soil water evaporation was low than the amount of water infiltration in thick overburden clay soil, so, the thick overburden soil could hold more water for the vegetation utilization. c) With the progress of soil water evaporation, the rate of evaporation was decreased with the increase of clay soil cover thickness. The greater the soil cover thickness, the stronger the soil water retention capacity. From the experimental result, the thick clay soil cover could remain more water, and is more suitable for vegetation establishment in post-mining restoration.

How to cite: chengzhi, L.: Influence of soil overburden thickness on water infiltration and evaporation characteristic in post-mine restoration, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7056, https://doi.org/10.5194/egusphere-egu23-7056, 2023.

EGU23-7139 | Posters virtual | ERE1.12

Correlation analysis of the change law of index gas and active functional groups in the process of high-temperature spontaneous combustion of minerals in the Fushun West Mine. 

Jia-Ming Chang, Jing-Yu Zhao, Jia-Jia Song, Ting-Hao Zhang, Gai Hang, Zhao-Long Chi, and Chen Wang

The spontaneous combustion of underground minerals causes huge property losses and ecological damage. Coal and oil shale are co associated minerals in the Fushun West Mine, and both have the ability of oxidative spontaneous combustion. To study the effect of microstructure changes on the macroscopic gas product concentration during the mineral oxidation spontaneous combustion process in the Fushun West Mine, this study used a high-temperature temperature-programmed test to obtain the change trend of gas product concentration in different oxidation stages of minerals. Using Fourier transform infrared spectroscopy (FTIR) technology, the changes in active functional groups of surface molecules during the process of mineral oxidation and spontaneous combustion were identified. Finally, using the gray correlation degree, correlation analysis between the concentration of gas products and the concentration of active functional groups in different oxidation stages was carried out. The key reactive functional groups affecting mineral spontaneous combustion were identified. The essential reason for the change in the gas product was revealed.

How to cite: Chang, J.-M., Zhao, J.-Y., Song, J.-J., Zhang, T.-H., Hang, G., Chi, Z.-L., and Wang, C.: Correlation analysis of the change law of index gas and active functional groups in the process of high-temperature spontaneous combustion of minerals in the Fushun West Mine., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7139, https://doi.org/10.5194/egusphere-egu23-7139, 2023.

EGU23-7247 | ECS | Orals | ERE1.12

PostMinQuake: analysis of post-mining induced micro-seismicity in former European hard coal regions. 

Paloma Primo Doncel, Tobias Rudolph, and Stefan Möllerherm

Underground mining operations, in which large amounts of rock are extracted, can induce seismic events. Furthermore, draining the water to prevent it from flowing into the mining works is necessary for hard coal mines. Once mining stops, the pumping rates of groundwater decrease or is no longer necessary, allowing the water level to return to its state prior to the construction of such mines. During the post-mining phase in hard coal regions, induced micro-seismicity represents a risk for future land use. The EU-PostMinQuake project, funded by the Research Fund for Coal and Steel (RFCS), aims to study the dependency of such events and the rising water table in hard coal basins to detect and manage the risks of post-mining seismicity. This contribution shows the relation between water and seismicity in four former underground hard coal mines located in Czech Republic, France, Germany and Poland.

How to cite: Primo Doncel, P., Rudolph, T., and Möllerherm, S.: PostMinQuake: analysis of post-mining induced micro-seismicity in former European hard coal regions., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7247, https://doi.org/10.5194/egusphere-egu23-7247, 2023.

Accurate identification of high temperature area of coal fire is the premise of coal fire control, coal fire monitoring is the test of coal fire control effect, coal fire detection and monitoring are the key and difficult points of coal field fire fighting engineering. This report first introduces the characteristics of high temperature anomalies in coal fire areas, Abnormal characteristics include: abnormal temperature, spontaneous potential, magnetic field intensity, resistivity, gas content. and then proposes targeted detection and monitoring methods on this basis. Commonly used methods include: Temperature measurement method, thermal infrared remote sensing method, natural electric field method, magnetic method, high density resistivity method, transient electromagnetic method, gas component measurement method, radon gas measurement method, and so on. Finally, comprehensive comparative analysis is adopted to achieve the purpose of identifying and monitoring the fire area.

How to cite: Yuan, Y.: Introduction of detection and monitoring methods in coal field fire, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7322, https://doi.org/10.5194/egusphere-egu23-7322, 2023.

EGU23-8255 | Posters virtual | ERE1.12

Study on the Flow Field Variation in Fracture Channel of Coalfield Fire 

Qing-Wei Li, Hui-Pan Fan, Li-Feng Ren, Yang Xiao, and Qiang Zeng

The coalfield fire area is widespread in the world. Numerous coal resources have been destroyed because of the large-scale coalfield fires. Meanwhile, toxic and harmful substances, such as carbon monoxide, carbon dioxide, methane, sulfide, and nitrogen oxide, etc., are numerously generated. All of them threat the local ecological environment and the economic development. The occurrence and evolution processes are complex, challenging the scientific prevention and control for coalfield fire. Gas transport mechanism is one of the key points that influence coalfield fire evolution and its efficient prevention and control. This investigation mainly pays attention to the flow filed in underground coalfield fire area. Combining physical test and numerical simulation, the transition law of the main air supply channel in underground coalfield fire area is studied, and the distribution characteristics of flow field in the channels are revealed. These are of great significance for revealing the evolution process of coalfield fire.

How to cite: Li, Q.-W., Fan, H.-P., Ren, L.-F., Xiao, Y., and Zeng, Q.: Study on the Flow Field Variation in Fracture Channel of Coalfield Fire, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8255, https://doi.org/10.5194/egusphere-egu23-8255, 2023.

EGU23-10406 | ECS | Posters virtual | ERE1.12

Intelligent coordinated control technology of dust-gas in underground excavation face in highly gas mine, China 

Yong Cao, Yang Xiao, Zhenping Wang, and Qingwei Li

As a chronic hazard, coal mine dust is widely distributed in mines around the world, especially in China, and the number of cases of pneumoconiosis caused by coal mine dust remains high every year. In highly gas mines, excavation work is at risk of exceeding gas concentrations, which could cause gas-coal explosions under certain conditions. The underground excavation face of the high gas mine urgently needs to solve the gas overrun problem caused by dust prevention and control work. In this work, gas-coal dust monitoring and early warning technology was used, to establish a treatment concept combining intelligent wind control and dust removal and gas overrun prevention and control. Via numerical simulation with FLUENT, to determine the air volume ratio of gas over limit prevention and control, the optimal dust removal air volume ratio, and applied in the field. The results indicated that the intelligent wind control technology had a excellent prevention effect on the problem of dust-gas coexistence.

How to cite: Cao, Y., Xiao, Y., Wang, Z., and Li, Q.: Intelligent coordinated control technology of dust-gas in underground excavation face in highly gas mine, China, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10406, https://doi.org/10.5194/egusphere-egu23-10406, 2023.

As a new green chemical inhibitor, ionic liquids can inhibit spontaneous combustion of coal by dissolving and destroying the active structure in coal. In order to investigate the influence of ionic liquids with different concentrations on the molecular structure and the characteristics of low temperature oxidation kinetics of coal at oxygen-poor environment, taking Wucaiwan coal sample in Zhundong mining area as the research object, the molecular structure model of Wucaiwan coal in Zhundong mining area is constructed, and 1-(2-hydroxyethyl)-3-methylimidazole tetrafluoroborate [HOEtMIm] [BF4] ionic liquid is selected. The effect of ionic liquid on coal is investigated from macroscopic and microscopic levels by means of NMR carbon spectroscopy, X-ray photoelectron energy, infrared spectroscopy, thermogravimetry and X-ray diffraction. The results show that different concentrations of [HOEtMIm] [BF4] ionic liquids increase the ignition temperature point and the maximum weight loss rate temperature point of coal samples. The percentage of weight loss in the rapid oxidation stage and the whole combustion process of spontaneous combustion decreases with the increase of ionic liquid concentration. Compared with coal samples treated with other concentrations, the coal samples treated with 15% ionic liquids show good stability, and the fluctuation range of combustion characteristics parameters is small, which shows that high concentration ionic liquids can effectively reduce the influence of temperature on coal samples. Different stages of coal spontaneous combustion oxidation follow different reaction mechanism. The activation energy of the coal samples treated with different concentrations of [HOEtMIm] [BF4] ionic liquids did not change obviously in the evaporation and desorption stages of water, and the flame retardant effect was mainly shown in the oxygen absorption and weight gain stages and thermal decomposition stages. Higher concentration of ionic liquids can make aliphatic, oxygen-containing functional groups and side chains in coal structure fall off , so that the macromolecules of coal are arranged more closely, and the arrangement of organic carbon atoms tends to be oriented and regular gradually. The concentration of ionic liquids changed the polymerization degree of coal macromolecules, and the concentration of ionic liquids was proportional to the polymerization degree of coal macromolecules.

How to cite: Hao, R. and Zeng, Q.: Effect of Ionic Liquids with Different Concentrations on Molecular Structure and Combustion Performance of Coal, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10504, https://doi.org/10.5194/egusphere-egu23-10504, 2023.

Dust suppressant is an important way to improve the efficiency of wet dust removal,but the dust suppressant currently used in mine is generally chemical dust suppressant,which faces challenging problems of low interfacial activity, high cost, poor degradation,as well as environmental pollution and other issues. To synthesis biological dust suppressant (BDS), a new idea of microbial fermentation technology is proposed. Response surface optimization method was used to explore optimal fermentation conditions. These results show that BDS can be produced to the maximum capacity under the conditions of temperature =37.56℃, pH =7.99, rotating speed =220 r/min, inoculant =2.17%, and liquid loading =59.89 ml.XRD, FTIR and HPLC-MS/MS were adopted to explore the structural features of BDS. Its molecular structure shows a cyclic lipopeptide. The wettability was tested with interface rheometer and we found its good wetting ability under the concentration of 0.06wt‰ compared with chemical dust suppressant. At the same time, dust reduction performance was studied with self-developed test system and BDS showed good performance in dust reduction efficiency. Its application prospects are broad, which may open a new situation for green and efficient control of mine dust.

How to cite: Wang, H. and Zhang, Q.: Basic research on application of green dust suppression materials in mines, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10676, https://doi.org/10.5194/egusphere-egu23-10676, 2023.

EGU23-16711 | Orals | ERE1.12

Utilization of coal wastes in municipal waste landfill reclamation – a Katowice-Wełnowiec case study, Poland 

Justyna Ciesielczuk, Monika J. Fabiańska, Magdalena Misz-Kennan, Jolanta Pierwoła, and Anna Abramowicz

Coal mining produces a huge amount of waste which is stored in dumps located in close vicinity of coal mines and settlements. As organic matter is still present in deposited claystones, mudstones, sandstones, carbonates, and conglomerates, they are susceptible to self-heating, causing environmental problems. However, these wastes can also be utilized to reduce the amount of waste and the number of dumps.

The municipal waste landfill, operating from 1991 to 1996 for the Katowice town in Wełnowiec district, in Upper Silesia Coal Basin, Poland, was reclaimed with coal wastes. In total, a rubbish dump collected about 1.6 million tonnes of urban waste, composed of ca. 22.5% of coal waste, ca. 21.5% of municipal waste, ca. 40% of building waste and the remainder of composting plant waste. The residents living next to the dump complained about unpleasant odours. This is why it was decided to reclaim the municipal waste landfill and form a multi-barrier system composed of 0.3 m of compacted coal mine wastes, 0.5 m of clays, 0.1 m of sand, 0.3 m of gravel, 0.6 m of uncompacted coal mine waste mixed with soil, and 0.4 m of humus on the top. In 2001, it was decided to exploit biogas (methane) from the dump, and a total of 39 boreholes were drilled. Unfortunately, the rehabilitation caused self-heating and self-ignition to occur, and the first intense fire broke out in the eastern part of the northern slope in November/December 2008, emanating harmful components to the soil, air, and groundwater.

We proved geophysically, that properly planned reclamation has never been performed. Much more coal wastes with much higher organic matter content were deposited on the dump without any packing and fire-preventing measures. The most intensive fire expanded at the northern slope and appeared as hot spots in the eastern and southern parts. The temperature was elevated exceeding 80oC in these places preventing plants from growing. The highest measured temperature reached 770oC at 0.3 m subsurface. Vents and fissures which emit hot exhalations containing water vapour, carbon mono- and dioxide, methane, and other light hydrocarbons were encrusted by exhalating minerals. There the dump surface was permeated with water and bitumen formed in pyrolytical conditions in a self-heating zone located deeper within the dump.

Geophysical methods revealed up to 26 m of municipal waste covered by the irregularly distributed material of varying thickness and composition instead of a designed 2.2-m-thick multi-barrier system. The real thickness of coal wastes used for reclamation of the municipal Wełnowiec dump was documented and amounts from 1 to 8 m. The consequence is intensive burning and the necessity of prevention. Where the volume of coal waste is not adequate for thermal activity, no thermal activity was noticed. Where the volume is only just sufficient, small hot spots (< ~20m in diameter) appear and wane. Where the volume of coal waste used in rehabilitation was much greater than planned, as on the northern slope of the dump, burning could spread for many years and require professional firefighting to stop it.

How to cite: Ciesielczuk, J., Fabiańska, M. J., Misz-Kennan, M., Pierwoła, J., and Abramowicz, A.: Utilization of coal wastes in municipal waste landfill reclamation – a Katowice-Wełnowiec case study, Poland, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16711, https://doi.org/10.5194/egusphere-egu23-16711, 2023.

The intracontinental High Atlas Mountains are the result of multiple tectonic events, from Late Permian-Early Mesozoic Pangea breakup to Cenozoic Africa-Eurasia convergence. Prior to the Cenozoic inversion event, the South Atlas Fault Zone (SAFZ), which surrounded the High Atlas from the south, witnessed for the growth of multiple basins during the Liassic rifting in the eastern segment of the belt. The present work aims to shed light on the development of the Beni Bassia Liassic basin through two faults components of the SAFZ, the E-W J. Amalou faulted anticline (ridge) and Garn Talou fault from the South. Preliminary investigations based on the combination of field data and satellite images reveal significant results regarding the evolution of the basin. In the Beni Bassia Basin, the Ouchbis-Pleinsbachian Formation is an alternating layer of conglomerate limestones and marls, containing olistoliths over 10 meters in length, resulting from the destruction of the underlying platform of the Idikel-Sinemurian Formation. This huge breccia developed at the foot of steep faults on the southern margin of the basin, during the acceleration of the Liassic rifting. During the Cenozoic deformation and uplift of the Eastern High Atlas, bedding directions of Jurassic formations denote progressive changes from E-W in the northwestern to approximately NW-SE to N-S in the southeastern part of the basin. Similarly, the dip direction changes from dipping towards the south to dipping southwest to westward, indicating a dextral movement due to NNW-SSE regional shortening driven by the plates convergence. Other smaller-scale structures confirm dextral transpression kinematics at several places east of the High Atlas, including easterly detachments recorded in Lower Jurassic carbonates. Further investigations are planned to quantify the stress, strain and mechanisms involved in the configuration of the Liassic basin and the subsequent Cenozoic transpression.

Keywords: Eastern High Atlas, South Atlas Fault Zone, Beni Bassia Basin, Jurassic, Inversion, Transpression.

How to cite: Es-sabbar, I., Amrouch, K., Soulaimani, A., and Skikra, H.: Cenozoic inversion of the Lower Jurassic Beni Bassia Basin in the Eastern High Atlas (Morocco): effect of the right lateral transpression along the South Atlas Fault Zone (SAFZ), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2104, https://doi.org/10.5194/egusphere-egu23-2104, 2023.

EGU23-2858 | ECS | Posters virtual | ERE1.13

Upper Crust structural evolution of the Alpine orogeny in an intracontinental belt: Western High Atlas (WHA) Mountains, Morocco 

Salih Amarir, Khalid Amrouch, Mhamed Alaeddine Belfoul, and Hamza Skikra

The Atlas system is an intracontinental chain established upon a Paleozoic substratum by the inversion of Triassic basins starting in the late Mesozoic-early Cenozoic. The inversion of the chain is related to the Atlas rift system that was influenced by the opening of the Central Atlantic in the West and the Tethys in the north. This was coeval with a regional exhumation following the Alpine shortening responsible for the continuous uplifting of the chain since Late Cretaceous. The structural history and chronology of events are still matter of debates. To contribute to this, we focus on the Western High Atlas (WHA) aiming a retro enactment of the paleo-stresses states, by analyzing deformation structures at various scales. The geological data were collected at different stratigraphic levels: from the contact Paleozoic basement/Mesozoic cover interface to the Triassic detrital formations of the Argana corridor in the east, to the Jurassic-Cretaceous and Cenozoic plateaus in the west. Preliminary results highlight two major tectonic events: (1)- a first extensive event, with sub-horizontal minimal principal stress σ3 oriented NW-SE, that is linked to the Central Atlantic basin opening. This event is characterized by pull apart basins structured into horsts and grabens. (2)- a second compressive event, marked by NE-SW to NNE-SSW shortening. The later is subdivided into two episodes: i- an early post-rift episode (Middle-Late Jurassic to Early Cretaceous), marked by stylolites and meso-structures that occurred at the beginning of the main uplifting stage. ii- a late compression episode, characterized by a maximum principal stress σ1 mainly oriented NNE-SSW to NNW-SSE, starting at the late Cretaceous and accelerating during the Tertiary, simultaneously with the Africa-Europe collision.

Keywords: Paleo-stress, Structural analysis, Atlas rift system, Tectonic inversion, Western High Atlas Morocco, Alpine orogeny.

How to cite: Amarir, S., Amrouch, K., Belfoul, M. A., and Skikra, H.: Upper Crust structural evolution of the Alpine orogeny in an intracontinental belt: Western High Atlas (WHA) Mountains, Morocco, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2858, https://doi.org/10.5194/egusphere-egu23-2858, 2023.

EGU23-2949 | ECS | Posters virtual | ERE1.13

Reconstructing the Pre-Alpine cycle of Moroccan Atlas system before the inversion phase 

Mouad Ankach, Khalid Amrouch, and Mohamed Gouiza

The Wilson Cycle (ca. 250-300 Ma) is driven by plate tectonics, and is expressed by the opening of oceanic basins, which are subsequently closed to form orogens. Morocco has experienced several orogenic cycles: e.g., Eburnean, Pan-African, Hercynian (Variscan) and Alpine (Atlasian). The last Wilson Cycle that shaped the geology of Morocco is the Alpine Cycle (300-0 Ma). It started by the dismantlement of the Pangea Supercontinent leading to the opening of the Atlantic Ocean and the Atlas rift system. The latter was subsequently aborted and inverted into a fold-and-thrust belt during the Cenozoic, due to the opening of the South Atlantic and the convergence between Africa and Iberia-Europe. The Atlas system of NW Africa includes two intracontinental ranges, the High and Middle Atlas extending ENE-WSW and NE-SW, respectively. It is a key piece in the Pangea breakup puzzle, as its evolution captures the kinematic of the African plate during Mesozoic to Cenozoic times. Several studies have examined the structural and stratigraphic architectures of the Atlas system during the rifting phase, by removing the Alpine inversion along palinspaticly reconstructed 2D sections. However, little was done to investigate the crustal structure and the amount of crustal stretching during the Triassic to Jurassic extension. This work aims to reconstruct the pre-alpine architecture of the Atlas system and link it directly with the evolution of the crust. Our goal is to provide insights into the amount of crustal thinning that took place during the Mesozoic rifting in the Atlas domain and constrain the strain distribution within the African plate during the dismantlement of the Pangea.

Key words: Wilson cycle; Atlas system; Pangea; Break up; Inversion; Pre-Alpine cycle.

How to cite: Ankach, M., Amrouch, K., and Gouiza, M.: Reconstructing the Pre-Alpine cycle of Moroccan Atlas system before the inversion phase, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2949, https://doi.org/10.5194/egusphere-egu23-2949, 2023.

EGU23-5266 | ECS | Posters on site | ERE1.13

Stress and strain patterns related to the inversion of the High Atlas aborted rift 

Hamza Skikra, Khalid Amrouch, Abderrahmane Soulaimani, and Salih Amarir

The Moroccan High Atlas is an Alpine fold belt formed by the structural inversion of Mesozoic rift basins during the Late Cretaceous-Cenozoic. The involvement of mantle-related thermal mechanisms is anticipated to account for the anomalously elevated orogen and surrounding plateaus and basins. In the range’s Western portion, the Marrakech High Atlas displays the most pronounced basement exposure at the range scale. Recent studies highlighted the role of thick-skinned tectonics thrusting and folding during the basin inversion. Although several works brought considerable insights into the actual understanding of the High Atlas structural evolution, there is still an ambiguity regarding the kinematics, paleostresses, and tectonic regime associated with the basin inversion. In the present work, we examine the paleostresses history of the High Atlas fold belt through analyses of mesostructures i.e. striated faults planes, micro-shear fractures/veins, tensile fractures/veins, stylolites and mesoscale folds, in the northern and southern borders of the Marrakech High Atlas. The aim of this work is to illustrate the tectonic complexity of orgenic belts developed in an intracontinental setting far from the plates’ collision boundaries.

How to cite: Skikra, H., Amrouch, K., Soulaimani, A., and Amarir, S.: Stress and strain patterns related to the inversion of the High Atlas aborted rift, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5266, https://doi.org/10.5194/egusphere-egu23-5266, 2023.

EGU23-5478 | Posters on site | ERE1.13 | Highlight

How to create the highest manganese ore grade in the world? A geodynamic story in the Atlas of Morocco. 

Augustin Dekoninck, Jocelyn Barbarand, Gilles Ruffet, Yves Missenard, Nadine Mattielli, Rémi Leprêtre, Abdellah Mouttaqi, Omar Saddiqi, Michèle Verhaert, and Johan Yans

The Imini mining district (Morocco) hosts the largest manganese (Mn) ore deposits of North Africa (~120.000 T in 2016). The area is world recognized for hosting several epigenetic karst-type high-grade manganese deposits in a 10-15 meters thick Cenomanian-Turonian dolostone unit. These unconventional Mn oxide deposits occur along a belt of ~25-30 km in the southern foreland of the intraplate Atlasic belt of Morocco. This is due to two laterally extensive ore bodies of nearly pure pyrolusite-rich manganese ores (72-88 wt.% MnO2) and a third discontinuous medium-grade coronadite-rich Mn ore (40–48 wt.% MnO2)(Dekoninck et al., 2016a, b; Gutzmer et al., 2006). Our recent works allowed precise dating and geodynamic reconstructions of the ore deposit genesis. The ore depositions occurred during (i) late Cretaceous to late Paleocene (~ 92 Ma, ~ 78–82 Ma, ~ 65–67 Ma and ~58 Ma), (ii) late Eocene (c. 36 Ma), and (iii) early Burdigalian to early Serravalian probably in two pulses at c. 19–20 Ma and c. 13 Ma (Dekoninck et al., 2021, 2023). This multistage deposition coincides with three geodynamic events linked to the uplift of the Atlas. The late Cretaceous uplift of the Atlas created the required hydraulic head to sustain (1) fluid-rock interactions between O2-poor acidic ground waters and the Triassic series source, (2) migration of the metal-rich low-temperature hydrothermal fluid from the rock source and (3) overpressure fluid in the Imini depositional site. The vanishing of Triassic series above the Imini anticline forced these hydrothermal fluids to mix with oxygenated ground and alkaline waters resident in the karst system and precipitated the Mn oxides. The N70°-oriented Atlasic tectonic structure controls the orientation of these epigenetic karst-hosted Mn deposits. The late Eocene – Early/Middle Miocene uplifts generated additional supplies and/or in-situ remobilizations of the primary late Cretaceous medium-grade ore to form the high-grade pyrolusite-rich ore.

References

Dekoninck et al. 2023 (accepted). Mineralium Deposita. Dekoninck et al. 2016. Mineralium Deposita 51, 13-23. Dekoninck et al. 2016. in: Mineral Deposits of North Africa. Springer International Publishing, Cham, pp. 575–594. Dekoninck et al. 2021. Mineralium Deposita 59, 935–956. Gutzmer et al. 2006. Economic Geology 101, 385–405.

How to cite: Dekoninck, A., Barbarand, J., Ruffet, G., Missenard, Y., Mattielli, N., Leprêtre, R., Mouttaqi, A., Saddiqi, O., Verhaert, M., and Yans, J.: How to create the highest manganese ore grade in the world? A geodynamic story in the Atlas of Morocco., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5478, https://doi.org/10.5194/egusphere-egu23-5478, 2023.

EGU23-8854 | ECS | Posters on site | ERE1.13 | Highlight

Integrated Workflow for Petroleum System Analysis: Application to the East Beni Suef Basin, Egypt 

Ahmed Yousef Tawfik, Robert Ondrak, Gerd Winterleitner, and Maria Mutti

Integrating geological and 2D basin modeling of the East Beni Suef Basin, located in north-central Egypt, allows extending burial and thermal history modeling into the deeper parts of the basin, which are not explored by drilling activities thereby evaluating the hydrocarbon potential of the actual kitchen areas. In addition, this regional approach allows us not only to study the hydrocarbon generation potential of the deeper kitchen area but also the migration and accumulation history of the basin. The East Beni Suef Basin (EBSB) is an extensional rift basin, which was initiated following the opening of the NeoTethys and Atlantic oceans and the associated tectonic motion of Africa with respect to Eurasia during the Early Cretaceous. Its stratigraphy comprises five main rock units of mixed siliciclastic-carbonates ranging from the Albian to the Eocene from base to top as follows: Kharita Formation, Bahariya Formation, Abu Roash Formation, Khoman Formation, and Apollonia Formation. The Upper Cretaceous Abu Roash Formation is divided into seven members based on the siliciclastic to non-clastic ratio and includes the main petroleum system elements of the basin, where the carbonate “F” Member is the source rock, while the siliciclastic portions of the “E” and “G” members constitute the reservoir rocks. This study aims to gain insight into the geological evolution of the EBSB and to improve our understanding of its Upper Cretaceous petroleum system, in terms of burial and thermal histories, source rock maturity, and hydrocarbon generation, migration, and accumulation. Thus, an integrated geological and basin modeling workflow was employed, making use of two basin-wide seismic sections, crossing the EBSB in SW-NE and NW-SE directions, and three boreholes with well data. The interpreted 2D seismic lines served as the basis to define the geometrical and structural framework and the development of the subsequent 2D basin modeling of the basin. Modeling results indicate that the Abu Roash “F” source rock maturity ranges from the early oil window at the basin margins to the main oil window in the center. The main phase of hydrocarbon generation occurred during the Eocene after trap formation in the Late Cretaceous. Generated hydrocarbons have migrated both laterally and vertically, most likely from the central part of the basin toward the basin margins, particularly eastward to the structural traps. The model predicts low accumulation rates for the EBSB, which are caused by the ineffective sealing capacity of the overburden rocks and normal faults. In addition to the proven kitchen for the charging of the Abu Roash “E” reservoirs, an additional kitchen to the west of the basin is suggested for the Abu Roash “G” reservoirs. The results of this work can better elucidate the present-day distribution of the Upper Cretaceous accumulations in the EBSB for further successful exploration activities.

How to cite: Tawfik, A. Y., Ondrak, R., Winterleitner, G., and Mutti, M.: Integrated Workflow for Petroleum System Analysis: Application to the East Beni Suef Basin, Egypt, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8854, https://doi.org/10.5194/egusphere-egu23-8854, 2023.

EGU23-12569 | Posters on site | ERE1.13

GIS-based morphotectonic and geomorphometric assessment for the Moroccan High Atlas mountain ranges, Morocco. 

Athanasios V. Argyriou, Hamza Skikra, Khalid Amrouch, and Abderrahmane Soulaimani

The geomorphological and tectonic processes being responsible for the control of the mountain ranges geometry is feasible to be assessed through geomorphological and morphotectonic indices. Those indices are dependent on tectonic or erosional processes and other factors influencing the development of the landforms. Tectonic geomorphology applications using satellite-based remotely sensed data, such as Digital Elevation Models (DEMs), can highlight specific geomorphic features capable to provide useful information and knowledge towards the evaluation of the regional tectonic activity in mountain ranges. This study examines the Moroccan High Atlas mountain range by using morphotectonic and geomorphometric indices such as the channel steepness index, amplitude of relief index, stream length gradient index, swath profiles, local relief and hillslope mapping to determine the distribution of the tectonic activity variations. Through those indices the evaluation of the geomorphic responses to tectonics takes place by highlighting the relationships between tectonic activity, rock resistance, stream channel slope, active or recent vertical displacements. The outcomes of the geomorphometric and morphotectonic investigation highlight the presence of considerable geomorphic variations across the main fault zones featuring the orogen’s anatomy, while tectonic activity seems to be a major factor controlling and shaping the Moroccan High Atlas mountain range landscape. The methodological framework of this study could be developed into a low-cost technique for assessing seismic hazard, offering a valuable tool towards assessing disaster risk reduction activities, whereas in conjunction with other factors the georesources exploration. 

 

Acknowledgements

The corresponding author acknowledges the 'EXCELSIOR': ERATOSTHENES: Excellence Research Centre for Earth Surveillance and Space-Based Monitoring of the Environment H2020 Widespread Teaming project (www.excelsior2020.eu). The 'EXCELSIOR' project has received funding from the European Union's Horizon 2020 research and innovation programme under Grant Agreement No 857510, from the Government of the Republic of Cyprus through the Directorate General for the European Programmes, Coordination and Development and the Cyprus University of Technology.

How to cite: Argyriou, A. V., Skikra, H., Amrouch, K., and Soulaimani, A.: GIS-based morphotectonic and geomorphometric assessment for the Moroccan High Atlas mountain ranges, Morocco., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12569, https://doi.org/10.5194/egusphere-egu23-12569, 2023.

EGU23-1054 | ECS | Posters on site | ERE1.14

Assessing the climate change risk to underwater cultural heritage: the EU-funded WATERISKULT project 

Luigi Germinario, Isabella Moro, and Claudio Mazzoli

The impact of climate change on cultural assets represents a topical subject of scientific research, although spotlighting heritage sites on land while often neglecting the vulnerability of the underwater world. The WATERISKULT project (https://wateriskult.geoscienze.unipd.it), funded by the European Union under the Marie Skłodowska-Curie Actions, aims at filling that gap. The project will provide the first quantitative assessment of the risk to underwater cultural heritage, with a focus on archaeological stone, a material part of countless remains of ancient cities and ship cargoes sunken in the oceans. This contribution introduces WATERISKULT by presenting its layout and first research activities, based on an interdisciplinary approach (including petrography, oceanography, analytical chemistry, marine biology, hydraulic engineering, and underwater archaeology) and a mixed field and laboratory experimentation. The key-factors of climate change under investigation involve ocean acidification, sea level rise, ocean warming, and extreme weather events. Moreover, the causes and effects of current deterioration of archaeological stone materials are being explored, considering the Mediterranean Sea as pilot area. The research results are expected to help assessing the observed and predicted decay trends of underwater heritage sites, constrained by the diverse characteristics of the component materials and submarine environments.

How to cite: Germinario, L., Moro, I., and Mazzoli, C.: Assessing the climate change risk to underwater cultural heritage: the EU-funded WATERISKULT project, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1054, https://doi.org/10.5194/egusphere-egu23-1054, 2023.

EGU23-2440 | ECS | Orals | ERE1.14

Extreme rainfall risk and climate change impact assessment for Edinburgh World Heritage sites 

Shane O'Neill, Simon Tett, and Kate Donovan

Change in climate extremes and the increased risk associated with human-induced global warming is apparent. Less apparent is the impact such changes may have on vulnerable systems in our society. Climate change impact assessments using state-of-the-art climate models coupled with damage information can offer actionable insight for stakeholders to better protect vulnerable systems.

Cultural heritage is an example of a system that is vulnerable to climate change, especially built cultural heritage which is directly exposed to changing climate extremes. In the UK, significant development has been achieved to better understand the potential change in climate extremes following the release of UK Climate Projections 18 (UKCP18), however, understanding of risk posed by these climate extremes to built cultural heritage is poorly constrained. How to assess and quantify this risk is in its infancy.

We have developed a new methodology building on previous work by cultural heritage experts - the Cultural Heritage Climate Risk Assessment (CHCRA) framework. The CHCRA framework focuses on combining stakeholder engagement and high-resolution climate models to develop site-specific projections of potential damage to cultural heritage assets. This integrated framework when applied with adequate information allows estimation of expected damages to cultural heritage assets through the 21st century.

We applied the CHCRCA framework to cultural heritage buildings in the Edinburgh World Heritage Site, Scotland, considering one-day extreme rainfall events. This pilot study used UKCP18 2.2 km resolution climate projections alongside qualitative and quantitative damage data obtained from multiple sources.

Importantly, UKCP18 2.2 km model is a Convection Permitting Climate Model with the ability to better represent extreme rainfall events. Furthermore, expert elicitation through interviews with practitioners from cultural heritage organisations within Edinburgh were carried out to obtain damage information specific to cultural heritage buildings in the Old and New Town Edinburgh (ONTE), part of the Edinburgh World Heritage Site. A damage function was derived based on expert elicitation and other sources.

Key findings include annual expected damage per year increases from 0.6% in the baseline period (1981-2000) to 1.5% in 2021-40 and 2.3% in 2061-80. A three-to-four-fold increase in annual expected damage to cultural heritage buildings in the ONTE is expected towards the end of the 21st century.

This is the first application of the CHCRA framework. This pilot study considered only one climate stressor, extreme one-day rainfall events. Damage at built cultural heritage is likely exacerbated and accelerated by other climate stressors, as well as non-climate related factors such as poor maintenance. Furthermore, damage caused by pluvial and/or fluvial flooding mechanisms were not taken into consideration, as well as no consideration given to reduction in risk due to adaptive measures.

This study provided insight into the changing risk posed by an impactful climate stressor to cultural heritage buildings in the ONTE. The study highlights the importance of stakeholder engagement from the outset when carrying out a climate change impact assessment. Further work may benefit from considering a more wide-ranging array of climate stressors to capture synergistic damage processes.

How to cite: O'Neill, S., Tett, S., and Donovan, K.: Extreme rainfall risk and climate change impact assessment for Edinburgh World Heritage sites, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2440, https://doi.org/10.5194/egusphere-egu23-2440, 2023.

EGU23-3237 | ECS | Orals | ERE1.14

Impact Assessment of Pollution and Climate-Induced Damage on Historic Centre of Rieti (Italy) 

Alessandro Sardella, Linda Canesi, Nisha Prashanth Setty, Raffaela Gaddi, and Alessandra Bonazza

The conservation and protection of cultural heritage, seen in its broadest definition, face ongoing and new challenges as a result of the impacts of slow and extreme climate changes. Therefore, there is the need of further studies and the development of improved methods in order to support decision makers and public authorities in preparing plans to manage and mitigate the correlated risks.

The present contribution aims at analysing and assessing the impacts of pollution and climate change induced extremes on the built heritage located in the historic centre of Rieti (Italy). This research has been conducted in the framework of the Interreg Central Europe Project STRENCH (STRENgthening resilience of Cultural Heritage at risk in a changing environment through proactive transnational cooperation, 2020–2022) and the National Italian Project "Piano Straordinario di Monitoraggio e Conservazione dei Beni Culturali Immobili'', coordinated by the Ministry of Culture. First, the pollutants data (NO2, SO2, O3, PM2,5 and PM10) extracted from air quality monitoring station at Rieti (IT0867A) were analysed and interpreted in accordance with the limiting values mandated by Italian law (legislative Decree 155 of 2010) for the characterization of air quality. Further, surface recession of carbonate stones for the period of 2011-2021 was calculated using Lipfert (1989) and Kucera et al. (2007) damage functions. Then, the “Risk Mapping tool for Cultural Heritage Protection” (https://www.protecht2save-wgt.eu/) was exploited: time series based on earth observation data (e.g. Copernicus C3S reanalysis and NASA GPM IMERG products), historical changes based on EOBS dataset and future hazard maps at territorial level based on outputs from regional and global climate models (EURO-CORDEX initiative) were investigated.

Obtained results reveal that a constant slight decline trend of pollutants annual average is shown over the years from 2011 to 2019. During 2020, lower values for each pollutant component were observed, partially attributed to the lockdown caused by the Covid19 pandemic. It was also observed that each investigated gaseous pollutant and PM fractions were within the limits regulated by the Italian Law.

Regarding the surface recession analysis, it was observed that it has been decreasing over the past 10 years from 2010 with slight increases occasionally. Also here, a decline in 2020 attributed to the lockdown is clearly observable. Moreover, most of particles contributing to PM can be certainly attributed to vehicular traffic, among anthropogenic sources, and are therefore in the fine fraction.

Finally, climate future projections, with spatial resolution of 12x12km, show a general increase of the changes of the extreme indices taken into consideration (R20mm and Rx5day); the biggest variations are typically foreseen for the far future (2071-20100), under the pessimistic scenario (RCP 8.5), highlighting a high likelihood of heavy rain and flooding risk in the area of Rieti.

How to cite: Sardella, A., Canesi, L., Prashanth Setty, N., Gaddi, R., and Bonazza, A.: Impact Assessment of Pollution and Climate-Induced Damage on Historic Centre of Rieti (Italy), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3237, https://doi.org/10.5194/egusphere-egu23-3237, 2023.

EGU23-5424 | Posters on site | ERE1.14

Characterization of the carbonate rocks of the Calcari di Cagliari Formation using a combined petrographic, geomatic and geophysical approach. 

Giuseppe Casula, Silvana Fais, Francesco Cuccuru, Maria Giovanna Bianchi, and Paola Ligas

The methods and the tools aimed at characterizing and analysing the carbonate materials used in the historic built heritage often follow different ways according to the different branches of applied research involved in the knowledge process. In this framework, the 3D digital models both of in situ architectural elements and of significative samples of rocks used as building materials can play an important role in relating different data and disciplines aimed at the prevention and conservation of the Cultural Heritage. Although the 3D geomatic and geophysical digital models represent privileged tools of the diagnostic analysis, they must be supported by the knowledge of the textural characteristics of the rocks under investigation with petrographic analyses. In order to study the stone materials heavily used in the historic built heritage and analyse their vulnerability to the conditions in their environment, it can be beneficial to study appropriately prepared samples and make as many measurements as necessary with different techniques. Moreover, some analyses are destructive and there is a limit to the number of samples that can be sacrificed. For this reason, in the analysis of rock samples, non-destructive techniques are constantly being improved. In this study, using a suitably implemented integrated methodology we analysed in detail samples of the carbonate rocks of the Calcari di Cagliari formation represented by Pietra Cantone, Tramezzario and Pietra Forte lithologies, mainly used in the past as construction materials for the buildings of the Historical Centre of Cagliari (Italy). Our methodology is represented by an integration of the geomatic survey carried out by structure-from-motion (SfM) digital close-range photogrammetry and the seismic tomography normally used for the in situ inspection adapted to laboratory tests on samples of the above lithologies using ultrasonic frequency signals. The rigorous metric of the geomatic 3D models was used to implement the ultrasonic survey by which internal characteristics and physical properties of the studied material are detected thanks to the spatial variations of the longitudinal velocity obtained after the tomographic inversion. The geomatic and geophysical data were complemented by an accurate analysis of the above carbonate materials by optical and scanning electron microscopy in order to detect their textural characteristics and especially the nature and distribution of their porosity. The microscopy analyses were integrated by mercury intrusion porosimetry (MIP) to obtain further information on the pore network, particularly on the effective porosity, pores-throat diameters/radii, permeability and tortuosity of the investigated materials. All the above parameters were found to affect the geomatic and geophysical behaviour of the carbonate materials. The integration of the multi-technique data produced in this study contributes to better understand the interaction between the investigated materials and the environment.

Acknowledgements

This work was supported by Regione Autonoma dellaSardegna (RAS) (Sardinian Autonomous Region), Regional Law 7th August 2007, no. 7, Promotion of scientific research and technological innovation in Sardinia (Italy), Resp. Sc. S.Fais.

How to cite: Casula, G., Fais, S., Cuccuru, F., Bianchi, M. G., and Ligas, P.: Characterization of the carbonate rocks of the Calcari di Cagliari Formation using a combined petrographic, geomatic and geophysical approach., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5424, https://doi.org/10.5194/egusphere-egu23-5424, 2023.

Built heritage, which gives identity to the urban fabric and fosters the collective memory of the community, is at risk of deterioration due to climate stressors. These stressors result from rapid urbanisation, covering surfaces with hard materials, and a disconnection from nature.

Today, nature-based solutions have become a growing trend as a way to reconnect with nature and mitigate the impact of climate change. Green infrastructures (GI), in particular, offer numerous environmental and social benefits, especially in dense urban areas, including improved air quality, reduced heat island effect, increased biodiversity and improved stormwater management, and stress-reducing and restorative effects on individuals.

Although built heritage sites form an important part of the urban fabric, they are often excluded from this green transition due to the risk of invasive species damaging historic buildings' structural and aesthetic integrity. Therefore, there is a lack of research analysing rigorously designed examples of GI in a historical context.

This study aims to narrow the focus to the sociocultural perception and acceptance of GI in a historical context. We will analyse spatial-perceptual patterns and socio-cultural motivations behind the deliberate use of GI in this context, using biophilic design principles and architectural perception theories as frameworks. Using GIS monitoring as a methodology, we will map and collect inventory data on real-life examples of GI applied to historical buildings in Belgium-Antwerp. The goal is to understand the correlations between spatial-perceptual factors and the use of GI in built heritage contexts.

How to cite: Kale, E., De Groeve, M., and De Kock, T.: Exploring the Socio-Cultural Compatibility of Green Infrastructures in Built Heritage Contexts: A Case Study in Antwerp (Belgium), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5685, https://doi.org/10.5194/egusphere-egu23-5685, 2023.

EGU23-5786 | ECS | Posters on site | ERE1.14

Pore-scale investigation of salt weathering in building heritage materials: combining AFM nano-indentation measurements and multiscale modeling. 

Clément Mathieu, Jérôme Wassermann, Pierre M. Adler, Sébastien Péralta, Jean-Louis Gallias, Ronan L. Hébert, and Philippe Bromblet

Salt weathering is a main cause of damage in building heritage materials. Despite the large amount of research on this topic, the mechanism of damaging processes remains not fully understood in particular at the pore scale where the salt crystallization and dissolution occur. For this reason, we propose an innovative approach combining damage proxy measurements at pore-scale using Atomic Force Microscopy (AFM), Raman spectrometry and multi-scale numerical modelling, performed during weathering cycles. Imbibition-evaporation cycles are performed on carbonate stones (Savonnières and Saint Maximin limestones) with a 0.1 mol/L sodium sulfate solution at controlled room temperature and relative humidity. The stone samples are especially designed for the measurements at the pore-scale. Cylinder of 1.6 cm diameter and 1.5 cm thickness have been coated with very viscous epoxy resin. Then the two sides of the cylinder have been polished to obtained two free surfaces that allow the fluid circulation in the sample and the measurements. After each weathering cycle, nanoindentation experiments are performed on representative areas of several hundreds of square micrometers in order to monitor the mechanical properties evolution. A force of the µN order is applied in order to stay in the elastic deformation regime. Young modulus values can be then deduced from the slope of the force curves that occurs during the cantilever deflection. With this method, the effect of salt weathering on the mechanical properties of stone minerals is investigated at the pore scale and with no impact of the measurement on the phases structure (reversible indentations). The AFM results are then coupled with chemical Raman mapping to identify the present phases and assign them their mechanical properties. The obtained experimental data are then used in numerical modeling, to generate a numerical Young modulus field with the same properties than the experimental field. Finally, a new medium with higher dimensions will be generated to compare the results with the macro-scale observations on building heritage stones. AFM characterization shows that changes occurred on the topography of the samples between the first and the third alteration cycles. They are of the order of several tens of nanometers and correspond either to salt crystals deposits or in some cases to the loss of material that took place between the second and the third cycle. A decrease of the Young modulus is observed after each cycle that is of the order of 2 GPa between the first and the second cycles. More significant changes are observed after the third cycle especially in some areas where a decrease up to 3 to 4 GPa is estimated.

How to cite: Mathieu, C., Wassermann, J., Adler, P. M., Péralta, S., Gallias, J.-L., Hébert, R. L., and Bromblet, P.: Pore-scale investigation of salt weathering in building heritage materials: combining AFM nano-indentation measurements and multiscale modeling., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5786, https://doi.org/10.5194/egusphere-egu23-5786, 2023.

EGU23-5956 | Posters on site | ERE1.14

Obtaining pore size distribution of porous stone using non-Newtonian fluids 

Martin Slavík and Martin Lanzendörfer

The characteristics of the pore space are considered a key factor in susceptibility of the stone to various weathering processes. The pore size distribution can be determined by a number of methods such as mercury intrusion porosimetry or computed topography. None of them is without disadvantages, namely the mercury intrusion porosimetry – despite being very popular – is the object of some critics due to the harmful effects of the mercury. Within the last decade, there has been a growing interest in the use of non-Newtonian fluids for obtaining the pore size distribution of the porous materials (see, e.g., Abou Najm and Atallah, 2016; Rodríguez de Castro et al., 2016). The principle exploits the behaviour of non-Newtonian fluids whose viscosity changes with shear rate. This is manifested by the fact that saturated flow of different fluids under different hydraulic gradients is distributed differently in the pore space. Therefore, conducting a set of saturated flow experiments with different fluids and/or under different hydraulic gradients allows – using a numerical model – to determine an approximation of the pore size distribution.

Our goal is to test feasibility of determining the pore size distribution using saturated flow experiments with low-concentration water-xanthan solutions (<1 g/l) under relatively small hydraulic gradients (<5). We have now completed a set of laboratory experiments for three types of sandstone and we are performing a sensitivity analyses of the parameters used in the numerical model. The presented approach is low-cost, easy-to-use and can serve as an alternative to mercury intrusion porosimetry in geoscience and various cultural heritage studies.

 

The research is funded by the Czech Science Foundation [21-27291S].

 

References:

Abou Najm, M.R., Atallah, N.M., 2016: Non-Newtonian Fluids in Action: Revisiting Hydraulic Conductivity and Pore Size Distribution of Porous Media. Vadose Zone Journal, 15(19), 1–15.

Rodríguez de Castro A., Omari, A., Ahmadi-Sénichault, A., Savin, S., Madariaga, L-S., 2016: Characterizing Porous Media with the Yield Stress Fluids Porosimetry Method. Transport in Porous Media, 114, 213–233.

How to cite: Slavík, M. and Lanzendörfer, M.: Obtaining pore size distribution of porous stone using non-Newtonian fluids, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5956, https://doi.org/10.5194/egusphere-egu23-5956, 2023.

EGU23-6252 | ECS | Orals | ERE1.14

Investigations of shallow aquifer groundwater systems of a Gallo-roman anthropized site using earth tide analysis 

Elijah Edet Nkitnam, Alexis Maineult, and Jérôme Wassermann

The prospect for the sustainability of the Gallo-Roman archeological site located in Genainville (France), where relics and artifacts dated to the 2rd century CE have been excavated is threaten by groundwater ingression. The in-situ building heritage materials and structures comprising a two cellea temple and an amphitheater made of limestones, are submitted all days to rising and changing groundwater levels; water being the main agent or vector of damage processes (salt weathering or freeze-thaw cycles). As part of a multi-disciplinary effort to support archeological expeditions and conserve the site structures. We report the results of groundwater monitoring and hydrogeological studies as well as tidal subsurface analysis executed to quantitatively evaluate hydraulic and geo-mechanical characteristics of the subsurface sequences toward a nondestructive approach. Continuous groundwater level data recorded in three wells in the archeological site were decomposed into constituent events that impact the observed fluctuations. The groundwater levels and barometric pressure data were acquired at 60 seconds intervals to study the response of the aquifer to strain and stress prevalence at the site. Using the method of regression deconvolution, the response to barometric pressure was disentangled from the measured water levels. Theoretical Earth tides parameters were computed using the PyGtide code, based on the ETERNA PREDICT program, at intervals of 1 minute. Harmonic analysis of the raw and filtered data using the classical Fast Fourier transform (FFT), and Singular Spectral Analysis (SSA) identify M2, S2, K1 and O1 tidal constituents as the dominant amplitudes. The SSA technique has the advantage of resolving the events into individual strands compare to the spectra of the composite data produced by the FFT. Hence, an event decomposed in the data is isolated in terms of it frequency and amplitude, and visualized. The K1 and S2 harmonic constituents were present in the filtered and raw data sets with different amplitudes. The amplitude response method was used to compute the poroelastic properties of the aquifer and characterize the subsurface heterogeneity. The model identified a semi-confined aquifer as the main groundwater storage system in the site.

Keyword: Heritage site, groundwater ingress, harmonic constituents, hydraulic properties

How to cite: Nkitnam, E. E., Maineult, A., and Wassermann, J.: Investigations of shallow aquifer groundwater systems of a Gallo-roman anthropized site using earth tide analysis, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6252, https://doi.org/10.5194/egusphere-egu23-6252, 2023.

EGU23-8060 | Orals | ERE1.14

Comparison of different kinds of models to simulate the alteration of medieval stained glass as a function of climate and pollution 

Aurélie Verney-Carron, Loryelle Sessegolo, Roger-Alexandre Lefèvre, and Peter Brimblecombe

A large number of stained glass windows were installed from the 13th century. During the Middle-Ages, most of glass pieces have a Si-K-Ca composition with a relatively low SiO2 content, but high content of K2O and CaO.  This chemical composition means that medieval stained glass deteriorates during environmental exposure, from climate and environmental pollution. These alterations are manifested in the form of an alteration layer and secondary phases (mainly gypsum or syngenite). The alteration layer is generally depleted in K and Ca, but rich in Si, Al and Fe. Its thickness varies up to 300 µm after 6 or 7 centuries of alteration. In order to reconstruct the alteration history and predict the deterioration of stained glass windows in the future, it is necessary to determine alteration rates as a function of the climate and environmental parameters.

Several methodologies can be used to achieve this. First, short-term exposures or laboratory experiments can assess the first stages of the alteration and short-term kinetics. From these results, dose-response functions (DRF) were established for sheltered and unsheltered rain conditions. They correlate relevant environmental factors (temperature, rain quantity, rain pH, relative humidity, SO2 concentration) with the response of the materials in terms of alteration layer thickness. The second methodology consists in laboratory experiments that aim at parametrizing kinetic laws as a function of specific parameters (temperature, pH of rain, and relative humidity). These kinetic parameters do not directly consider pollution, but they can be extrapolated over long periods and can be inputs to geochemical models. In this study, we have compared both methodologies to simulate the alteration of a model stained glass at different European sites (using data from the ICP-Materials program). Both models give good results, but the geochemical model tends to underestimate the alteration at polluted sites. This indicates that the pollution via the concentration in SO2 for example should be included to improve the model.

How to cite: Verney-Carron, A., Sessegolo, L., Lefèvre, R.-A., and Brimblecombe, P.: Comparison of different kinds of models to simulate the alteration of medieval stained glass as a function of climate and pollution, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8060, https://doi.org/10.5194/egusphere-egu23-8060, 2023.

Moisture and salts cause considerable damage to built and rock-hewn heritage. Rock moisture is a key factor for numerous decay processes, but there is limited knowledge of salt and moisture distribution because measurements of spatial and temporal moisture distribution still remain challenging. The medieval cave town of Uplistsikhe (Georgia) is hewn out of very soft Lower Miocene sandstone and is a typical example of a heritage site suffering from progressive decay. We present data on moisture and salt distribution derived from a multi-method approach, including microwave sensor monitoring (MW-mon; continuously over 2 yrs), microwave handheld sensors (MW), 2D-resistivity profiles (ERT), rock sampling by drilling, and salt extraction by paper pulp poultices (PPP).

Microwave monitoring was applied for the first time (to our knowledge) in a long-term monitoring of heritage sites. We used equipment from hf-sensor (Germany) with two types of microwave reflectivity sensors penetrating approx. 7 cm and 13 cm deep, respectively. The sensors were installed inside and outside of two prominent caves (Grand Hall and Long Hall). MW, ERT, PPP and drilling were carried out in four caves (the two mentioned plus Blackberry Hall and Teatron). Careful laboratory calibration using samples from the site was necessary to produce quantitative results for MW-mon, MW and ERT.  

MW-mon showed pronounced annual fluctuation with highest moisture saturation occurring in summer. The moisture maximum in the caves lags 2 months behind the spring precipitation maximum and might be partly caused by air humidity condensation amplified by salts. Heavy rainfall events cause additional moisture pulses by seeping through the rock or by capillary rise. Spatial moisture distribution derived from MW shows relatively dry rock outside the caves and different patterns of moisture ingress into the caves: Capillary rise from the base, ingress through fractured or otherwise water-permeable areas of the roofs or back walls. The spatial patterns are confirmed by ERT; however, calculated moisture saturation differs between MW and ERT due to electrical conductivity effects of salty pore water.

All drill samples from the caves are significantly saltier on the respective surfaces, which points to the rate of evaporation being smaller than the outward migration of salts. Outside the caves, flaking of thicker layers (several cm) point to deeper layers of salt concentration caused by higher evaporation from the surface; flaking at the "lips" above the caves is probably also amplified by stronger temperature and moisture fluctuations. The main ions everywhere are  Ca2+ and SO42- (subordinate K+) while at the strongly flaking surfaces of Grand Hall, Na+, Cl- and NO32- are also present. Summing up, the results show very diverse and complex patterns of moisture and salt distribution at an apparently homogeneous site.

How to cite: Sass, O. and Fruhmann, S.: Spatiotemporal rock moisture distribution at the medieval cave town of Uplistsikhe, Georgia, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8442, https://doi.org/10.5194/egusphere-egu23-8442, 2023.

EGU23-11011 | Posters on site | ERE1.14

Evaluation of salt weathering equations. – a review 

Chiaki Oguchi

Salt weathering of building stone is a major cause of loss of historic structures. Many geoheritage sites including stone heritage and geomorphosites have been damaged by this process. In nearly two centuries, research and observation relating salt weathering have accumulated. These studies could be organized focusing on theories, mechanisms, experimental methods, and research tools. This presentation introduce by reviewing many, though not enough, studies to summarize the research history of salt weathering, including the results of subsequent studies, especially focused on an important mechanism of salt weathering, crystallization pressure. Since the concept of crystallization was first proposed in the early 20th century, many equations have been proposed. However, in order to apply them correctly, it is important to consider the type of salt weathering and the surrounding environment, as well as the type and properties of salt and rock (rock properties), and to select and apply the proposed model according to the situation. Although salt weathering studies have been done in a wide variety of research fields, appropriate collaboration among disciplines will lead to meaningful conservation and will be used for practical problems in the future.

How to cite: Oguchi, C.: Evaluation of salt weathering equations. – a review, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11011, https://doi.org/10.5194/egusphere-egu23-11011, 2023.

EGU23-11840 | Posters virtual | ERE1.14

Smart IoT sensors as part of a holistic solution for improving resilience and sustainable reconstruction of historic areas 

Dr. Antonis Kalis, Nikos Mitro, and Dr. Angelos Amditis

Although Climate Change (CC) has already been reported to have a significant impact on historical areas hosting Cultural Heritage (CH) sites, it is still challenging to assess quantitatively and qualitatively the impact of various climatic and other parameters on the CH sites, since the specific climatic conditions at their vicinity, and the emanating effects on their structure, are difficult to grasp due to cost and regulatory barriers. In the framework of the HYPERION EU project, we address this problem by providing a holistic solution for improving resilience and sustainable reconstruction of historic areas, which integrates the use of smart IoT devices, called Smart Tags, designed to provide environmental measurements close to monuments, with a number of state-of-the-art of technologies, services and tools (e.g. advanced ML, IoT, satellite and terrestrial imaging, social networking, event, material decay and business continuity modelling), in order to develop a single decision support system which aspires to become the cornerstone for resilience and reconstruction planning for historic areas in the future.

How to cite: Kalis, Dr. A., Mitro, N., and Amditis, Dr. A.: Smart IoT sensors as part of a holistic solution for improving resilience and sustainable reconstruction of historic areas, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11840, https://doi.org/10.5194/egusphere-egu23-11840, 2023.

EGU23-11948 | ECS | Orals | ERE1.14

Selection of relevant black crusts samples as ancient air pollution archives 

Mathilde Ropiquet, Aurélie Verney-Carron, and Anne Chabas

Since the Industrial revolution and due to increasing anthropogenic emissions, the composition of the atmosphere has been modified, leading to climate change and pollution. The impacts of pollution were depicted through paintings and writing from the beginning of the 19th century, but pollution measurements are relatively recent. In order to obtain ancient air pollution data, proxies in urban area need to be found.

Black crusts formed on limestone and marble monuments in urban area seem to be a good candidate as local proxy. Mainly composed of gypsum (CaSO4.2H2O), they are a chemical alteration pattern resulting from the reaction of the dissolution of the calcite (CaCO3) of the stone and of sulfation by sulphur dioxide (SO2) from the atmosphere. Particulate matter accumulates in the newly formed gypsum layer in sheltered area from the rain, thus giving the black crust a passive sampler potential.

To use black crusts as past air pollution archives, samples were collected at Père Lachaise cemetery (Paris) on ancient, dated (1820-1887) and unrestored limestone or marble tombs. Different types of analyses were performed to study sample morphology (by Optical Microscope), particulate matter (by Scanning Electron Microscopy) and chemical composition (especially major elements and trace metals by ICP-AES, LA-ICP-MS). Results underline two important features to use black crusts as past air pollution archives. First, the low variability of chemical composition of black crusts from Père Lachaise cemetery highlights that the black crusts are representative of the site and register the background pollution. Then, the morphology (laminar vs. dendritic) of black crusts is a key parameter to sample black crusts as the stratigraphy is much better preserved in laminar black crusts.

How to cite: Ropiquet, M., Verney-Carron, A., and Chabas, A.: Selection of relevant black crusts samples as ancient air pollution archives, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11948, https://doi.org/10.5194/egusphere-egu23-11948, 2023.

EGU23-12449 | ECS | Orals | ERE1.14

The technical relationship between vertical greening and built heritage 

Marie De Groeve, Eda Kale, Scott Allan Orr, and Tim De Kock

Built heritage is rich in cultural and economic values and is an essential part of urban environments. These buildings are abundant in city centres that have been the site of development for several centuries. This has produced a dense environment, exhibiting strong urban heat island effects. Green initiatives are increasingly being implemented to mitigate current climate stressors and improve the health and well-being of residents. However, built heritage is often excluded from these approaches due to concerns about their impact on materials and structural integrity, which is poorly understood. 

This research scopes the technical compatibility of vertical greening with built heritage in an urban environment regarding the degradation of historic building materials. Vertical greening here is understood to include plants, rooted in the ground, growing along a vertical surface by either attaching themselves to the façade or trellising. Investigating the impact of vertical greening on the local microclimate by monitoring case studies, lab experiments and analysing current literature can help us understand how vertical greening affects common forms of degradation caused by salts, frost, bio-activity and air pollution. Each method has its own approach to understanding the relationship of vertical greening with built heritage and is complementary to the others. The lab experiments explore the three main factors impacted by vertical greening such as temperature and relative humidity, incoming solar irradiation and precipitation exposure. Temperature and relative humidity are inseparably connected with each other and therefore analysed together. The impact of vertical greening on the aforementioned environmental parameters is investigated separately to provide better insights into those microclimatic changes that determine the risk of weathering of historic building materials.

How to cite: De Groeve, M., Kale, E., Orr, S. A., and De Kock, T.: The technical relationship between vertical greening and built heritage, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12449, https://doi.org/10.5194/egusphere-egu23-12449, 2023.

EGU23-12934 | ECS | Posters on site | ERE1.14

Microclimatic monitoring of the plaster casts of the Trajan’s Column in the Museum of Roman Civilisation (Rome) 

Federica Bubola, Eleonora Balliana, Chiara Coletti, Claudia Cecamore, Claudio Parisi Presicce, and Claudio Mazzoli

In recent years, the control of the micro-climate in museum environments or in historical buildings has assumed a role of great importance for the protection of the artefacts exhibited and for planning cost-effective and strategic preservation policy. The process of degradation indeed, defined as a result of progressive and cumulative material decay, strongly depends by environmental variables and their changes. Rapid changes and/or strong gradients in temperature and/or relative humidity, are the main causes of internal stress and of material surface detachments. Compared to new museums, historical ones often do not dispose of ideal conservation parameters, and they need specific conservation environments, considering the so-called historical climate, i.e. the microclimate to which the Cultural Heritage has adapted over the time. This is the case of the Museum of Roman Civilisation (Rome), which has been closed since 2014 and hosts a huge and valuable collection of plaster casts, such as those of the Trajan’s Column made by Napoleon III in 1861-1862 and gifted from Vatican City to Rome City Hall in 1953. In view of the imminent museum reopening and restoration, it is essential to define the actual level of microclimate quality, compared to the expected one, considering also economic and regulatory aspects and the future welfare of the artefacts. The research is focused on the response of the materials to the micro-climate by evaluating the incidence of temperature and relative humidity, presumably the main chemical and physical degradation factors for the plaster casts. A multidisciplinary diagnostic approach (i.e. Hyperspectral Imaging, Raman Spectroscopy, Infrared Spectroscopy) is also planned to characterise the constituent materials, to suppose the manufacturing techniques of the casts and to identify the degradation forms. The analysis of the complex interaction between the dynamics of the climate and the need for the conservation of the artefacts under conditions of maximum stability represents the starting point for proposing a sustainable restoration of the Trajan’s Column plaster casts of the Museum of Roman Civilisation and a future exhibition project that will allow their valorisation and exposure.

How to cite: Bubola, F., Balliana, E., Coletti, C., Cecamore, C., Parisi Presicce, C., and Mazzoli, C.: Microclimatic monitoring of the plaster casts of the Trajan’s Column in the Museum of Roman Civilisation (Rome), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12934, https://doi.org/10.5194/egusphere-egu23-12934, 2023.

EGU23-13158 | Posters on site | ERE1.14

The use and vulnerability of medieval masonries in Balaton region, Hungary 

Ákos Török, Bendek Logó, and Annamária Kis

The geology of the region strongly influences the construction materials of Medieval structures and, consequently, the available raw materials. The current study focuses on the use and vulnerability of various lithotypes and renders in a Medieval Ruined Chuch in West Central Hungary, close to Lake Balaton. The church was constructed in the 13th century and was rebuilt in several periods using various lithotypes and renders. The identification of primary lithologies followed the generation of point clouds by Terrestrial Laser Scanner and the drawing of walls. More than ten various stone types were found, including Jurassic cherty limestone, cemented Triassic limestone (Muschelkalk), basalt tuff, basalt, red Permian sandstone, grey Tertiary sandstone, highly porous Miocene limestone, and travertine. The properties of stones and condition assessment were made by using non-destructive on-site strength tests such Schmidt hammer and Duroskop. Micro-drilling technique was also applied to assess the strength parameters of renders: medieval lime-based mortars, 20th-century portland cement based mortars. Small samples were also taken for laboratory analyses. Our studies suggest that the application of portland cement bearing renders in the 20th century caused significant damage to the structure, accelerating weathering processes. Medieval lime mortars are relatively durable and show smaller-scale alterations. The use of various lithotypes leads to differential weathering of the structure. The long-term preservation of this building depends on the use of appropriate renders and the refurbishment of wall sections that are structurally unstable.

How to cite: Török, Á., Logó, B., and Kis, A.: The use and vulnerability of medieval masonries in Balaton region, Hungary, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13158, https://doi.org/10.5194/egusphere-egu23-13158, 2023.

EGU23-13243 | Orals | ERE1.14

IT support for climate resilient cultural heritage - examples from the KERES project 

Jürgen Moßgraber, Tobias Hellmund, and Lola Kotova

Not only ecosystems are particularly sensitive to extreme weather as a result of climate change. Historical buildings, museum’s collections and historical gardens can also be affected by extreme weather conditions. Assessing the extent to which cultural assets are endangered by such weather and climate events is an interdisciplinary task that requires the collaboration of climate scientists together with cultural heritage managers, monument conservators, restorers and engineers. However, this discussion is currently hardly taking place in Germany, both on a scientific and on policy levels.

Therefore, the BMBF-funded project KERES addresses the following questions:

  • What safety risks of our cultural heritage are caused by extreme weather events?
  • Which practical solutions need to be addressed and managed the current and emerging impacts of climate change on cultural assets in Germany?

In close cooperation with the relevant stakeholders and potential users, such as the Prussian Palaces and Gardens Foundation (SPSG), Fraunhofer IOSB is building a web-based knowledge platform that combines the research results and best practices for adaptation and mitigation measures of the historical buildings and historical parks property. This aims to create the greatest possible degree of user orientation so that the knowledge platform can be used sustainably in the long term. This platform is able to collect and integrate multisource information in order to effectively provide complete and updated situational awareness and decision support for innovative measurements improving cultural heritage resilience, in particular new solutions for maintenance and conservation. It is based on the open source; easily configurable and extendable. It can be accessed by the wide range of users via the web interface.

Several levels of data integration, aggregation and linking are aggregated:

  • integration of expert knowledge,
  • connection of sensors for comprehensive monitoring

and reporting,

  • data analysis of complex processes with an open interface

for easy integration of new algorithms,

  • semantic and geographic linking of analysis data and
  • multiple domain information.

The backbone of this information network is an ontology, which connects the data of the different domains, like cultural heritage, climate change, environmental data, crisis management, regulations, sensor data management, buildings, materials and many more. The platform is flanked by two other applications, such as a planning tool for the evacuation of art objects:

  • This is a tool for creating route maps for the fire brigade to evacuate cultural objects.
  • The decision-maker supports finding individual measures against damage caused by climate change.

The applications for preventive and reactive measures to deal with potential or acute damage situations are examined as well. The designed methods are tested for five case studies including historical buildings and historical gardens in Germany.

How to cite: Moßgraber, J., Hellmund, T., and Kotova, L.: IT support for climate resilient cultural heritage - examples from the KERES project, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13243, https://doi.org/10.5194/egusphere-egu23-13243, 2023.

EGU23-13666 | Orals | ERE1.14

Global warming evidence in long-term temperature monitoring of heritage karstic caves 

François Bourges, Bruno Lartiges, Frédéric Perrier, Dominique Genty, Rémi Losno, Stéphane Bonnet, Vincent Regard, Stéphanie Touron, Faisl Bousta, Frédéric Girault, and Pascal Foucher

The outstanding preservation of Paleolithic decorated caves is related to the buffering properties of their karstic environment. However, long-term monitoring of air/wall temperatures and gas compositions has recently revealed disruption signs in cave microclimates that had been maintained stable for hundreds of centuries.

High precision and continuous temperature data records are currently monitored in various prehistoric caves in the South of France. Such operations have been promoted since the late 1990s by the French government for risk assessment and conservation.

The most striking feature is the positive drift of underground temperatures (air and wall) which is now obvious in most sites except for Niaux Cave (> 300 m undersurface) and in the deepest parts of Mas-d’Azil and Chauvet Caves (> 50 m undersurface). In tourist caves (Pech-Merle, Mas-d’Azil, Gargas, Villars), the positive thermal trends could not be related to the energy increase brought by visitors which number is now stable, nor to the lighting systems whose energy demand was strongly reduced. In addition, the underground thermal drift nearly starts at the same time in many caves with uncertainties of +/- 1 year: 2012 for Chauvet with +0.4 °C/decade, 2011 for Pech Merle with +0.32 °C/decade, 2011 for Marsoulas Cave with +1.09 to +0.36 °C/decade from the entrance to the deep gallery, 2011 for Gargas with +0.69 °C, +0.54 °C and +0.36 °C for the deeper station. It is worth noting that a 0.3-0.4 °C thermal drift is consistent with that predicted from global warming in these regions.  The thermal drifts were already in progress when monitoring began in Villars Cave in 1996 (+0.17 °C to +0.39 °C/decade), in Mas-d’Azil in 2012 and in Bruniquel in 2015. Marsoulas (+1.09 °C/decade) and Mas-d’Azil (more than +1 °C/decade in 6 of the 16 stations) present a much higher drift rate compared with that of surface, which suggests a thermal amplification process.

As measurements are performed in heterothermal zones, the long-term thermal drifts are modulated by persisting smoothed and out-of-phase yearly variations. A notable exception is the case of Bruniquel main gallery where the temperature records show a quasi-linear increase. In that case, the decadal evolutions of temperature +0.31 °C, +0.175 °C, and +0.24 °C, are not related to the depth of monitoring stations (32 m, 55 m, and 38 m, respectively) nor to their distances from the entrance. In 2018, those drift rates induced a permanent inversion of thermal gradient in the main gallery. In Gargas, the drift rate is more pronounced in the outer parts of the karst body, thus inducing a continuous evolution of the thermal gradients within the galleries.

Such underground microclimate disruption of patrimonial caves is a warning signal of direct threat on the preservation of remains. Karst physical organization and its related underground environment are themselves legacies of past climates; the current functioning of transfer zones of karst aquifers which includes the caves, are directly dependent on the outside climate. A more comprehensive approach and modelling of possible tipping points are urgently needed for conservation issues.

How to cite: Bourges, F., Lartiges, B., Perrier, F., Genty, D., Losno, R., Bonnet, S., Regard, V., Touron, S., Bousta, F., Girault, F., and Foucher, P.: Global warming evidence in long-term temperature monitoring of heritage karstic caves, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13666, https://doi.org/10.5194/egusphere-egu23-13666, 2023.

EGU23-13699 | ECS | Posters on site | ERE1.14

Assessing weathering damage in Arenitic Rock using Non-Destructive Testing: the case study of the stone coats of arms of Palazzo Ricasoli in Florence 

Eugenio Segabinazzi, Teresa Salvatici, Irene Centauro, Sara Calandra, and Carlo Alberto Garzonio

Assessing weathering damage in Arenitic Rock using Non-Destructive Testing: the case study of the stone coats of arms of Palazzo Ricasoli in Florence 

The conservation of architectural heritage often involves studying the effects of weathering on stone materials exposed to polluted environments with characteristics unfavorable to their preservation. The decay phenomena that occur in urban environments can lead to destructive effects on stone material, resulting in the need for specific analysis to assess the mechanical properties of these artifacts. 

In this study, we analyzed three stone coats of arms that decorate the facade of Palazzo Ricasoli in Florence using non-destructive diagnostic techniques (NDTs) to assess their degree of weathering.  

Palazzo Ricasoli is a historic Renaissance palace, located in the center of Florence, that features three stone coats of arms on its façade that are currently in critical condition, showing signs of very advanced degradation. The stone of which they are composed is a type of local sandstone rock commonly used in Florentine historical architecture. 

To investigate the properties of the material we used in situ techniques, such Sonic test and 3D scanning. The results obtained with these techniques were then compared with those obtained from laboratory analysis of micro-samples using methods such as Fourier transform infrared spectroscopy (FTIR), X-ray Diffraction (XRD), X-ray Fluorescence (XRF), and optical microscopy.  

Using NTDs we were able to gather data and insights on the mechanical properties of weathered rock used in historical buildings, obtaining crucial information that can be used to develop appropriate and detailed conservation strategies to ensure the long-term stability of these materials in their environmental conditions.

How to cite: Segabinazzi, E., Salvatici, T., Centauro, I., Calandra, S., and Garzonio, C. A.: Assessing weathering damage in Arenitic Rock using Non-Destructive Testing: the case study of the stone coats of arms of Palazzo Ricasoli in Florence, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13699, https://doi.org/10.5194/egusphere-egu23-13699, 2023.

EGU23-14025 | Posters on site | ERE1.14

Climate change impact of salt weathering on vernacular and archaeological cultural heritage building materials in Europe and Latin America 

Beatriz Menendez, Julian Esteban Cantillo, and Benjamin Quesada

Salts are widely present in all porous building materials. Their chemical composition, degree of hydration and crystalline phase as well as their abundance and location in the building are highly variable. In addition, these parameters depend on the type of material, the location and environmental factors such as climate, air pollution or groundwater composition.  The crystallization of salts inside porous materials depends on the nature of the solutions present in the pores and the conditions under which it occurs. Environmental, climatic and pollution conditions have changed in the past and continue to change today.

In this work we will estimate the changes of the potential salt weathering in vernacular cultural heritage in Europe and archaeological sites in Latin America, in particular in the selected regions of the European project SCORE (Sustainable COnservation and REstoration of built cultural heritage 2021-2024). In order to determine how future climatic conditions may affect salt weathering in these sites, climatic conditions in different models, based on scientific literature, will be used. Salt weathering will be estimated for different salts: Na2SO4, NaCl, and mixture of salt.

For temperatures between 0 and 30 ° C, the solubility of sodium chloride is almost constant (around 26% by mass) while that of sodium sulfate is very variable (between 5% and 20% by mass). Changes in temperature will induce precipitation/dissolution more easily for sodium sulphate than for sodium chloride. Similar conclusions can be drawn for changes in relative humidity in the case of crystals. In the case of sodium sulphate, the crystalline phase changes between the anhydrous salt (thenardite) and the decahydrated salt (mirabilite) and the deliquescence will depend on both temperature and relative humidity. In the case of sodium chloride with a single degree of hydration at temperatures above 0°C, the deliquescence is almost independent of temperature, with a relative humidity of almost constant equilibrium around 75%. In general, salts that have only one state of hydration have a lower capacity of degradation than salts with several phases of hydration. Phase diagrams will be employed to quantify the weathering induced by thee salts.

In nature as well as in buildings, it is common to find associations of salts more than pure salts, which complicates the study of the dependence of salt crystallization on environmental conditions. The variety of salts that can be formed by crystallization of solutions containing several different anions and cations is extremely important. The behavior of mixed solutions is much more complicated than that of solutions containing a single species of cation and anion. For complex solutions, the crystallization pathways as a function of composition and environmental conditions cannot be directly deduced from that of the salts taken separately. Thermodynamic models can be very useful for modeling the sequence and conditions of salt crystallization in a solution. We used the ECOS-RUNSALT model to calculate the evolution of salt volume as a function of temperature and relative humidity conditions to estimate the weathering produced by complex solutions.

How to cite: Menendez, B., Esteban Cantillo, J., and Quesada, B.: Climate change impact of salt weathering on vernacular and archaeological cultural heritage building materials in Europe and Latin America, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14025, https://doi.org/10.5194/egusphere-egu23-14025, 2023.

EGU23-15431 | Posters virtual | ERE1.14

The Loggiato dei Cappuccini in Comacchio (Italy): assessment of degradation and state of conservation. 

Elena Marrocchino, Lorenzo Ferroni, Rino Manfrini, Maria Grazia Paletta, and Chiara Telloli

Cultural heritage is an irreplaceable component of a country's socio-cultural and economic capital, valuable for community cohesion and for the creation and enhancement of social capital, economic impact and environmental sustainability [1-4]. Unfortunately, the vulnerability of cultural heritage has increased over time and its exposure to a series of slow and sudden natural and man-made hazards threatens its existence.

Comacchio is a small municipality in the province of Ferrara (Emilia-Romagna region in north-eastern Italy), in the southern part of the present-day Po River estuary. It is an early medieval settlement, mainly known for the presence of several Etruscan settlements in its territory [5]. Comacchio is the result of continuous variations in sea level and the Po River, the extent of subsidence phenomena, and finally human activity over the last five thousand years.

The Loggiato dei Cappuccini has always been a symbol of the town of Comacchio for its simple and pleasant aesthetic characteristics, for the shelter it can offer from the weather and the summer sun, for its secluded position with respect to the town centre and for its connection with the sanctuary of the Virgin Mary in Aula Regia, which has always been venerated here [6,7].

This study aims to enhance the Capuchin Loggia through an analysis of the monument's state of conservation. The research started with a historical analysis of the maintenance and restoration work that the monument has undergone over time. Subsequently, macroscopic observation and bibliographic research also analyzed the current degradation morphologies and their causes. The proposed analysis campaign may be used by the Municipality of Comacchio to plan future rehabilitation and restoration works aimed at the conservation of the historical-cultural heritage.

References

  • Cultural Heritage Counts for Europe. Full Report of the EU Project “Cultural Heritage Counts for Europe: towards a Eu-ropean Index for Cultural Heritage”, 2015. https://www.europanostra.org/our-work/policy/cultural-heritage-count s-europe/
  • Culture 2030 Indicators: Thematic Indicators for Culture in the 2030 Agenda. United Nations Educational, Scientific and Cultural Organization, 2019. http://uis.unesco.org/sites/default/files/documents/publication_culture_202 0_indicators_en.pdf
  • Transforming our world: the 2030 agenda for sustainable development. Resolution A/RES/70/1, United Nations General Assembly, United Nations, 2015. https://sustainabledevelopment.un.org/post2015/transformingourworld/publication
  • Romão, X.; Bertolin, C. Risk protection for cultural heritage and historic centres: Current knowledge and further research needs. Int J Disaster Risk Reduc, 2022, 67, 102652,
  • Gelichi, S. L’Isola del Vescovo, Firenze, Edizioni all’insegna del Giglio s.a.s., 2009.
  • Alberti, A. Segnali di una ritrovata cultura della manutenzione urbana e architettonica a Comacchio, FE. Quaderni di soprintendenza : Qds, 2001, 5.
  • Zamboni, A. La fabbrica dei pesci dietro il loggiato dei Cappuccini e la sede amministrativa delle Valli Comunali di Comacchio. In: Anecdota, Quaderni della Biblioteca L.A. Muratori Comacchio, Ferrara, Gabriele Corbo Editore, 2001, 1/2, 1.

How to cite: Marrocchino, E., Ferroni, L., Manfrini, R., Paletta, M. G., and Telloli, C.: The Loggiato dei Cappuccini in Comacchio (Italy): assessment of degradation and state of conservation., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15431, https://doi.org/10.5194/egusphere-egu23-15431, 2023.

EGU23-16553 | ECS | Posters on site | ERE1.14

Porosity evolution of granitic rocks used for the bridge construction 

Vendula Natherová, Richard Přikryl, Daniela Řimnáčová, Martin Racek, and Jiřina Přikrylová

Granitic rocks are generally ranked to very low porosity (open porosity of fresh, non-weathered granite should be below 1 vol. %) and durable rocks. Favourable physical properties dictate their choice for monumental works and important infrastructural projects such as bridges.

Current study focuses on detailed analysis of porosity evolution in granitic rocks used for the construction of two road bridges (making part of cultural heritage of the Czech Republic) over the Vltava River in Prague (Bohemian capital) in the second half of 19th c. After 120-150 service, many of the stone ashlars of load-bearing parts exhibit quite extensive decay phenomena; however, mostly close to the exposed surfaces. In order to understand causes of decay, several tens of samples obtained from decayed surfaces and from original source quarries were studied by various methods, namely mercury intrusion porosimetry (MIP) and optical and scanning electron microscopy.

Based on the results, porosity of granites in the stone masonry significantly increased compared to that of source rocks: two principal types of granites show open porosity 0.53-0.82 vol. %, and 1.03-1.15 vol. % respectively. In the case of granitic samples from studied bridges, their open porosity ranged from 2.13 to 6.42 vol. %. Most of the pores rank to coarse pores and macropores (according to IUPAC terminology), content of mesopores is negligible.

Significant increase of porosity reflects dynamics of decay process in a specific microclimate in Vltava River valley and polluted atmosphere of the city. However, pre-quarrying history of granites is another important factor: the examined rock types belong to the oldest members of the Central Bohemian Plutonic Complex of Variscan age, and numerous discrete hydrothermal alteration phenomena present in the studied rocks can promote their susceptibility to decay as well.

How to cite: Natherová, V., Přikryl, R., Řimnáčová, D., Racek, M., and Přikrylová, J.: Porosity evolution of granitic rocks used for the bridge construction, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16553, https://doi.org/10.5194/egusphere-egu23-16553, 2023.

The PARADeS project uses participatory approaches to contribute towards enhancing Ghana’s national flood disaster risk reduction and management strategy. The project was initiated by practitioners from Ghana and the problem setting was developed during a definition phase of the project. When the project started, commitment and strong partnership and involvement of partners were already established - a prerequisite for collaborative and non-extractive research.

Multiple workshops and focus group discussions were ‘successfully’ conducted in collaboration with our local partners. Despite the sound basis of the project (e.g. shared goal(s), strong and committed partnership), we experienced challenges before, during and post fieldwork. In this contribution, we particularly reflect and focus on including and managing different types of participants. On the one hand, we engaged with representatives from different governmental institutions and non-governmental organizations with mostly academic background during the workshops. On the other hand, flood-affected urban and rural citizens with strongly differing educational backgrounds and socio-economic assets elaborated on their flood experiences during the focus group discussions. Here, three main themes and challenges arose:

  • Selection of participants: Identifying blind spots of researchers and local partners, e.g. the risk of missing out marginalized voices,
  • Expectations management: Coping with expectations of participants and communicating own room of action, and
  • Feedback processes: Preventing extractive research by feedbacking information relevant to the participants

During the session, these themes are discussed using the guiding principles for fieldwork with participants (see Rangecroft et al. 2020) by highlighting ethics, communication, power dynamics and positionality. For this, we share our experiences and lessons learned e.g. how we deal with the problem of getting a gender balanced participant list or how we manage unexpected structures of focus groups. Furthermore, we would like to share our uneasiness when, for example, a focus group discussion turned into a community talk or unrealistic though understandable expectations were raised. By sharing our successes and pitfalls, we would like to contribute to a broader discussion on how to improve fieldwork, prepare for surprise and, especially, to meet expectations of participants, partners and researchers without compromising each other’s needs and integrity. 

 

Rangecroft, S., M. Rohse, E. W. Banks, R. Day, G. Di Baldassarre, T. Frommen, Y. Hayashi, B. Höllermann, K. Lebek, E. Mondino, M. Rusca, M. Wens and A. F. Van Loon (2020). "Guiding principles for hydrologists conducting interdisciplinary research and fieldwork with participants." Hydrological Sciences Journal: 1-12.

How to cite: Höllermann, B. and Ntajal, J.: Managing participants, expectations and surprises during fieldwork – Experiences from collaborative flood risk management in Ghana, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-207, https://doi.org/10.5194/egusphere-egu23-207, 2023.

EGU23-851 | ECS | Orals | EOS4.1

Organisational preparedness for the physical risks of climate change in the UK 

Denyse S. Dookie, Declan Conway, and Suraje Dessai

Understanding local perceptions of preparedness, risk and response to climate change is important for effective adaptation-focused actions and policy design. While there have been national surveys of the public’s concern, organisational perspectives are less studied. This research presents findings of a national survey of UK-based organisations’ perceptions about adapting to a changing climate. The survey covers awareness among organisations of climate change, its physical risks and how organisations are taking action to prepare for perceived risks. Administered in spring 2021, our survey summarises the insights of 2,400 respondents in roles related to organisational planning. The majority of respondents (69%) were from the private sector, while others came from public health authorities, local authorities, public educational establishments, and third sector or charitable organisations. 58% of respondents identified the effects of climate change as a concern. While the survey results support a picture of UK organisations taking steps to prepare for similar extreme weather events in the future, action is strongly informed by dealing with the effects of extremes already experienced. There is a much lower proportion of organisations taking measures to deal with the physical risks of future climate change. In terms of future action, organisations perceived a strong role for leadership from government and collective responsibilities for adaptation, signalling a need to recognise this in efforts to promote adaptation. These findings, though UK-centric, provide insight to societal responses, options and pathways, especially at the organisational level for the less widely studied private sector, as noted in IPCC AR6 WGII Chapter 13: Europe. 

How to cite: Dookie, D. S., Conway, D., and Dessai, S.: Organisational preparedness for the physical risks of climate change in the UK, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-851, https://doi.org/10.5194/egusphere-egu23-851, 2023.

Professional experiences led geoscientists initially to put together epistemic-moral hybrids [1], e.g. The Cape Town Statement on Geoethics  [2]. Then, combining geosciences and political philosophies more comprehensively, geo-philosophical assessments of human practices as part of the Earth System emerged [3] [4]. These assessments describe the Human-Earth Nexus amalgamating insights into (i) the dynamics of the Earth System; (ii) socio-historical features of human societies; (iii) philosophical appraisals of socio-political choices.

Scholars of the history of science recently developed a theory of the evolution of knowledge [5] [6] [7]. Applied to societies experiencing anthropogenic global change, they discern the concept of an ergosphere to depict the essence of the Human-Earth Nexus. “With their rapidly evolving culture, humans have introduced an “ergosphere” (a sphere of work, as well as of technological and energetic transformations) as a new global component of the Earth system, in addition to the lithosphere, the hydrosphere, the atmosphere, and the biosphere, thus changing the overall dynamics of the system.“ [6, p. 7].

The historians’ theory of evolution of knowledge offers geoscientists notions (e.g. borderline problem, economy of knowledge, and external representation) for assessing human practices, e.g. (i) a ‘borderline problem’ defined as: “problems that belong to multiple distinct systems of knowledge. Borderline problems put these systems into contact… (and sometimes into direct conflict) with each other, potentially triggering their integration and reorganisation” [7, p427]; (ii) an ‘economy of knowledge’ defined as: “societal processes pertaining to the production, preservation, accumulation, circulation, and appropriation of knowledge mediated by its external representation” [7, p.429]; (iii) an ‘external representation’ defined as: “any aspect of the material culture or environment of a society that may serve as an encoding of knowledge” [7, p. 224].

Concluding: (i) taking a geo-philosophical perspective means, per se, specifying a borderline problem, an economy of knowledge, and an external representation; (ii) the theoretical findings of the history of science offer a standardised methodology for geo-philosophical studies, namely asking: What borderline problem? What economy of knowledge? What external representation? Responses will discern sharper the socio-historical features of geo-philosophical topics, be it geoheritage or the Human-Earth-Nexus.

[1] Potthast T (2015) Toward an Inclusive Geoethics—Commonalities of Ethics in Technology, Science, Business, and Environment. In: Peppoloni MW (ed) Geoethics. Elsevier, pp 49–56

[2] Di Capua G, Peppoloni S, Bobrowsky P (2017) The Cape Town Statement on Geoethics. Ann Geophys 60:1–6. https://doi.org/10.4401/ag-7553

[3] Di Capua G, Bobrowsky PT, Kieffer SW, Palinkas C (2021) Introduction: geoethics goes beyond the geoscience profession. Geol Soc London, Spec Publ SP508-2020–191. https://doi.org/10.1144/SP508-2020-191

[4] Bohle M, Marone E (2022) Phronesis at the Human-Earth Nexus: Managed Retreat. Front Polit Sci 4:1–13. https://doi.org/10.3389/fpos.2022.819930

[5] Rosol C, Nelson S, Renn J (2017) Introduction: In the machine room of the Anthropocene. Anthr Rev 4:2–8. https://doi.org/10.1177/2053019617701165

[6] Renn J (2018) The Evolution of Knowledge: Rethinking Science in the Anthropocene. HoST - J Hist Sci Technol 12:1–22. https://doi.org/10.2478/host-2018-0001

[7] Renn J (2020) The Evolution of Knowledge - Rethinking Science for the Anthropocene. Princeton University Press, Oxford, UK

How to cite: Bohle, M.: Takings from the History of Science for Geo-philosophical Studies, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1204, https://doi.org/10.5194/egusphere-egu23-1204, 2023.

EGU23-1385 | Posters on site | EOS4.1 | Highlight

An expanded definition of geoethics 

Giuseppe Di Capua and Silvia Peppoloni

Geoethics incorporates instances, categories, concepts, principles, and values already present in the cultural debate, and develops an original theoretical and interdisciplinary framework that merges reflections and considerations that animate philosophical, political, sociological, economic, and (geo)scientific discussions. Geoethics analyses critically and rationally theoretical and practical issues of local and global importance (from climate change, to defense against geohazards and the use of geo-resources), in order to guide social stakeholders towards more inclusive, sustainable, and ecologically-oriented choices.

Geoethics can be qualified as:

  • universal and pluralist (it defines an ethical framework for humanity, in the awareness that the respect of the plurality of visions, approaches, tools is essential to assure dignity to all agents and to guarantee a wide range of opportunities for developing more effective actions to face common threats).
  • wide (its issues and reflections cover an extensive variety of themes);
  • multidisciplinary (its approach favors cooperation and overcoming the sectoral languages of the individual disciplines, to reach the intersection and integration of knowledge);
  • synthetic (it expresses a position of synthesis, definable as ecological humanism, between various existential concepts and different conceptions regarding the nexus between human being and Earth system);
  • local and global (its topics of interest concern both local and regional dimensions, as well as the global one related to the entire Earth system);
  • pedagogical (it proposes a reference model to cultivate one's ethical dimension, to reach a greater awareness of the value of human identity, not in terms of exercisable power over the other by oneself, but of respect of the dignity of what exists);
  • political (it criticizes the materialism, egoism, and consumerism of capitalism, prefiguring a profound cultural change of economic paradigms, and supports the right to knowledge as the foundation of society).

By contributing to change the perception of the nexus between the human being and the Earth system and consequently the social and legal structures of the organization of human communities, geoethics defines educational and political horizons for reaching a global reform of society (Peppoloni and Di Capua 2021: https://doi.org/10.3390/su131810024).

Based on these considerations, the definition of geoethics, as included in the Cape Town Statement on Geoethics (Di Capua et al. 2017: https://doi.org/10.4401/ag-7553) and internationally adopted, can find a new, broader formulation, which also describes better its theoretical structure and operational logic:

Geoethics is a field of theoretical and applied ethics focused on studies related to human-Earth system nexus. Geoethics is the research and reflection on principles and values which underpin appropriate behaviors and practices, wherever human activities interact with the Earth system. Geoethics deals with ways of creating a global ethics framework for guiding individual and social human behaviors, while considering human relational domains, plurality of human needs and visions, planetary boundaries, and geo-ecological tipping points. Geoethics deals with the ethical, social, and cultural implications of geoscience knowledge, education, research, practice, and communication and with the social role and responsibilities of geoscientists.

How to cite: Di Capua, G. and Peppoloni, S.: An expanded definition of geoethics, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1385, https://doi.org/10.5194/egusphere-egu23-1385, 2023.

EGU23-1391 | Posters on site | EOS4.1

Proposal of ethical guidelines for the European Research Infrastructure EPOS 

Silvia Peppoloni and Giuseppe Di Capua

In the science and technology domain, common methods, procedures, and protocols (rules allowing to make science) guarantee the quality and reliability of scientists’ and technicians’ work. When those rules are adequately followed, there should not arise any problems in deciding what is the best action to take while carrying out research and technological activities. But this is not enough to ensure that activities are conducted ethically.

Ethics influences personal and collective conduct and thereby shapes relationships and resulting outcomes. Research institutions/networks/organizations and their operators have societal responsibilities since their activities may have an impact on stakeholders, partners, and general end users with consequential effects on the economy, society, culture, public policy or services, health, the environment, or quality of life that goes way beyond a purely academic impact. Science, technology, and ethics are closely interconnected and they mutually influence the subject of their analyses and reflections. Thus, research and technological activities have to consider ethics to develop their full potential.

The mission of EPOS is “To establish and underpin a sustainable and long-term access to solid Earth science data and services integrating diverse European Research Infrastructures under a common federated framework.” This mission encapsulates ethical aspects that must be considered by the EPOS community (scientists, technicians, and data providers, who have different roles and therewith responsibilities within the EPOS community) and that are reflected in EPOS’ goals (https://www.epos-eu.org/about-epos).

In the EU H2020 EPOS-SP project, we developed first draft of the ethical guidelines for the EPOS community, that considers the following EPOS key-concepts:

  • multidisciplinary research;
  • integrated use of data, models, and facilities;
  • appropriate legal solutions;
  • common and shared data policy;
  • open access policy;
  • transparent use of data;
  • mutual respect of intellectual property rights.

The ethical guidelines are essential for establishing an informal “contract” between all members of the EPOS community for managing the relationships within the research infrastructure and with partners by defining principles and values to be shared for building a community of purposes, that is a set of individual and institutional subjects who share an organization, a language, a mission, goals to be achieved, a working method and operational tools.

These guidelines shall ensure that the research conducted within EPOS and services operated in this context are done in an ethical way.

The ethical guidelines are an orienting document for the implementation of the EPOS ERIC’s (European Research Infrastructure Consortium) tasks towards its reference community and stakeholders and are preparatory to the drafting of the final version of the EPOS ERIC ethical guidelines on which to develop subsequent ethical codes for managing specific activities or issues concerning EPOS activities.

How to cite: Peppoloni, S. and Di Capua, G.: Proposal of ethical guidelines for the European Research Infrastructure EPOS, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1391, https://doi.org/10.5194/egusphere-egu23-1391, 2023.

EGU23-2805 | Posters on site | EOS4.1

Study on the effective disaster risk management and communication for resilient community 

Mo-Hsiung Chuang, Kuo-Chen Ma, and Yih-Chi Tan

This 27th United Nations Climate Change Conference clearly pointed out that global warming is progressing. The threat of climate change and extreme disasters will increase rapidly, and the risk of community disasters will increase significantly. Therefore, effective disaster risk management and risk communication can enable community residents in disaster potential areas to understand disaster risks and build disaster prevention organizations, which has become a Practitioner in Disaster Risk Management. This study aims to explore training methods for resilient Communities. These include community environment diagnosis map making, including natural disaster risk and vulnerability discussion and disaster prevention map drawing, and secondly, how to train resilient community to conduct disaster risk control and disaster management measures before or during disaster events and recovery periods. Finally, combine the geographic information of the public sector and volunteers to conduct public-private cooperation to build disaster risk management and practice with resilient communities as the key players.

How to cite: Chuang, M.-H., Ma, K.-C., and Tan, Y.-C.: Study on the effective disaster risk management and communication for resilient community, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2805, https://doi.org/10.5194/egusphere-egu23-2805, 2023.

EGU23-3462 | Posters on site | EOS4.1 | Highlight

How to collectively engage in reducing the carbon footprint of a research lab? 

Jean-Philippe Vidal, Céline Berni, Marina Coquery, Alexandre Devers, Leslie Gauthier, Claire Lauvernet, Matthieu Masson, Louise Mimeau, and Martin Turlan and the RiverLy Downstream team

This communication aims at testifying how individual commitments of researchers can be combined to engage a whole research lab – in this case INRAE RiverLy – in a carbon transition path. INRAE RiverLy is an interdsciplinary research unit for the management and restoration of river systems and their catchments. In 2020, a group of RiverLy people started questioning the downstream impacts of their research practices. An official internal action called RiverLy Downstream was thus launched to address these issues. A first lab-scale carbon accounting for the year 2019 was performed thanks to the GES 1point5 tool (https://apps.labos1point5.org/ges-1point5). It showed a large contribution of air travel to the total carbon footprint. Further carbon accounting for 2020 and 2021 however highlighted the even larger impact of purchases (equipment, consumables, etc.) thanks to newly implemented features in GES 1point5. An open “climate day” was organized in the lab in September 2022 for (1) raising awareness through a general-public-oriented tool, (2) provide live feedback from other research labs engaged in a carbon transition, and (3) collectively identify propositions of local actions on different themes: purchases, travels, premises, computing, food, and research activities. These propositions fed a lab-wide survey that will help defining a few carbon footprint reduction scenarios based on their social acceptability. These scenarios will then be submitted to the lab board for implementation. The whole process benefited from rich interactions with INRAE national to regional strategy for reducing its environmental footprint (https://www.inrae.fr/en/corporate-social-responsibility-inrae), and with the French national initiative Labos1point5 (https://labos1point5.org/).

How to cite: Vidal, J.-P., Berni, C., Coquery, M., Devers, A., Gauthier, L., Lauvernet, C., Masson, M., Mimeau, L., and Turlan, M. and the RiverLy Downstream team: How to collectively engage in reducing the carbon footprint of a research lab?, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3462, https://doi.org/10.5194/egusphere-egu23-3462, 2023.

EGU23-4066 | Posters on site | EOS4.1

Supradisciplinary approach: a (geo)ethical way of producing knowledge and guiding human actions in the XXI Century. 

Eduardo Marone, Martin Bohle, and Rika Prieser

Once upon a time, super-specialization and intra-disciplinary approaches were highly rated, although implying divisions of knowledge1. How to challenge such epistemic boundaries? The disciplinary methodology for creating knowledge is important, particularly when subject to solid quality control. However, it is often faulty when handling broad complex systems, such as Natural or Social ones, despite scholars building elaborated methodologies, such as multi-, inter, trans-, and cross-disciplinary practices2. They provided insights and knowledge generation, although showing limitations3,4,5 (epistemic, field domination, egos, etc.).

Geoethics, looking into appropriate behaviours and practices wherever human activities interact with the Earth system6, is an example of the above, which requires overcoming limitations of disciplinary approaches by aiming at supradisciplinary7: engaging with a subject matter across a range of discourses/fields without giving rise to an interdisciplinary hybrid or sui generis discipline.

Exploring what a supradisciplinary practice means, a networkn of scholars proposes a tactic to assemble fellows from the People Sciences and the Natural Sciences: (i) A respectful epistemic trespassing8 allows crossing traditional disciplinary boundaries, and applying proper supradisciplinary collaboration seems more ethical than other methodologies. (ii) Organizing the team under a rhizomatic structure9 does not allow any scientific field hierarchy, avoiding the dilemma of preferring transdisciplinary approaches versus interdisciplinary or multidisciplinary ones and vice versa. Epistemic trespassing is a powerful tool for creating new supradisciplinary knowledge, avoiding the usual hyper-protection (and egos) related to any disciplinary epistemic backyards. It must be considered that supradisciplinary collaboration depends strongly on the quality of the given scientific problem and the proper promotion of the needed epistemic metamorphosis, which seems a more ethical and efficient way of producing knowledge.

 

1 Klein, J. T., & Miller, R. C. (1983). The Dialectic and Rhetoric of Disciplinary and Interdisciplinary. Issues in Interdisciplinary Studies.

2 Van den Besselaar, P., & Heimeriks, G. (2001). Disciplinary, multidisciplinary, interdisciplinary: Concepts and indicators. In ISSI (pp. 705-716).

3 Okamura, K. Interdisciplinarity revisited: evidence for research impact and dynamism. Palgrave Commun 5, 141 (2019). https://doi.org/10.1057/s41599-019-0352-4

4 Editorial. How to avoid glib interdisciplinarity. Nature 552, 148 (2017). DOI: https://doi.org/10.1038/d41586-017-08465-1

5 Kotter, R., Balsiger, P. W., Bailis, S., & Wentworth, J. (1999). Interdisciplinarity and transdisciplinarity: a constant challenge to the sciences. Issues in Interdisciplinary Studies.

6 Peppoloni, S., Bilham, N., & Di Capua, G. (2019) Contemporary Geoethics Within the Geosciences. In: Exploring Geoethics. Springer International Publishing, Cham, pp 25–70

7 Balsiger, P. W. (2004). Supradisciplinary research practices: history, objectives and rationale. Futures, 36(4), 407-421.

8 Ballantyne, N. (2019). Epistemic trespassing. Mind, 128(510).

9 Deleuze, G., & Guattari, F. (1987) [1980]. A Thousand Plateaus. Translated by Massumi, Brian. University of Minnesota Press. p. 21. ISBN 0-8166-1402-4.

n The Network: Alexandra Aragão, Alessia Rochira, Anamaria Richardson, Antony Milligan, Bruno Costelini, Carlos A.S. Batista, Carlos Murillo, Carsten Herrmann-Pillath, Claire A. Nelson, Cornelia E. Nauen, Eduardo Marone, Francesc Bellaubi, Jas Chambers, Javier Valladares, Luis Marone, Martin Bohle, Nic Bilham, Paul Hubley, Rika Preiser, Sharon Stein, Silvia Peppoloni, Vincent Blok, Will Steffen.

How to cite: Marone, E., Bohle, M., and Prieser, R.: Supradisciplinary approach: a (geo)ethical way of producing knowledge and guiding human actions in the XXI Century., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4066, https://doi.org/10.5194/egusphere-egu23-4066, 2023.

EGU23-4384 | ECS | Posters on site | EOS4.1

Social safety in the field – preparing the students, our future colleagues 

Kalijn Peters, Steye Verhoeve, and Wiebe Nijland

Watching the documentary ‘The Leadership’ led to a consentient discussion amongst colleagues. In this documentary a group of female scientists set off on a cruise to learn about and experience leadership. Personal experiences, what happens on board and statistics about social safety, show that feeling socially safe and included is still an issue amongst (female) scientists, especially when working in the field. The significantly high numbers of female field scientists in STEM research having experienced discrimination, gender inequality and (sexual) harassment cannot be ignored, so we decided this subject has to be embedded in our bachelor curriculum.

In order to enhance social safety in our earth sciences program, we set up a workshop on this subject for our bachelor students as part of a 15ECTS fieldwork course. In the field, students are physically and mentally challenged, while operating in an often unfamiliar environment, working in bigger and smaller groups, for longer periods of time and integrating all they have learned over the past year(s). With the many challenges this encompasses, they will likely face the boundaries of their comfort zone. This makes them more vulnerable and increases the risk of creating an unsafe working, studying/living environment. However, when treated with care, these experiences can have a significant positive impact on the students personal growth and become beneficial to their professional skills and learning.

The workshop we designed starts with discussing daily practicalities and individual responsibilities, including sanitary hygiene and proper field-equipment, and continues with professional attitude, an exercise on group dynamics, how to function in a team that is not your own choice, and getting to know your teammates in a playful manner. We finish with the discussion of (sexual) harassment, providing tools to become an active bystander, and giving the students case studies of socially (un)safe settings in the field. They present these case studies to each other on how they would react, reflecting on their own capabilities and responsibilities.

After this first year, student evaluations and discussions with field staff point out that this is a valuable part of the fieldwork. For example the staff could more easily refer to some manners discussed in the workshop, and the students could recognize the case studies and use this to tackle unsafe situations at an earlier stage. We now continue with optimizing the existing workshop, and would like to exchange experiences about this subject with colleagues to enhance improvement of social safety and personal growth in the field for both students and teaching staff.

How to cite: Peters, K., Verhoeve, S., and Nijland, W.: Social safety in the field – preparing the students, our future colleagues, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4384, https://doi.org/10.5194/egusphere-egu23-4384, 2023.

The unprecedented acceleration of human extractions of living and mineral resources particularly after WWII and their wasteful transformation in an expanding technosphere is now estimated to exceed living matter[1]. This fossil fuel driven acceleration has led to exceeding planetary boundaries in several dimensions [2], including the on-going mass extinction of species particularly in the warming and overfished ocean. Catch reconstructions since the beginnings of global statistics in 1950 are revealing the extent of unsustainable extractions from the ocean[3]. Two decisions at global negotiations in 2022, one on harmful fishing subsidies and the landmark target 3 on the protection of 30% of ocean and land by 2030, have potential to slow down the excesses and gradually rebuild fully functional ecosystems. How can scientists enhance their contribution towards shifting the emphasis to implementation? We know from cognitive science, e.g. that excessive car speed and other forms of sensory overload stress humans and reduce quality of life while also harming the environment[4]. Yet even in the face of evidence, it has often been impossible to act decisively on this evidence. Similarly, it has so far been been difficult to overcome widespread cognitive dissonance about climate change and species extinctions in the ocean. Contrary to widely held beliefs, here it is postulated that different attitudes are not impervious to scientific information and learning. Historically these judgemental processes are not fixed, even when reinforced by social norms[5]. However, the accumulation of facts and their presentation in the scientific literature is not enough to bring about what may be considered desirable behavioural change. This is reflected in considerable effort put into policy briefs and other dissemination formats in recent years, including video and social media e.g. by the IPCC. Art of hosting and collective leadership are other proven approaches for building understanding and trust necessary to develop robust solutions through enabling collective action. In their various context-adapted formats they have been successfully deployed for joint learning and action in settings as diverse as largely illiterate small-scale fishing communities and government organisations. They could benefit research and academic institutions in their search for promoting more stakeholder engagement and fostering greater inter- and transdisciplinarity.

[1] Elhacham, E., Ben-Uri, L., Grozovski, J. et al. Global human-made mass exceeds all living biomass. Nature 588, 442–444 (2020). https://doi.org/10.1038/s41586-020-3010-5

[2] Steffen, E., Richardson, K., Rockstroem, J. et al. Planetary boundaries: Guiding human development on a changing planet. Science 347(6223) (2015). DOI: 10.1126/science.1259855

[3] Pauly, D. & Zeller, D. Catch reconstructions reveal that global marine fisheries catches are higher than reported and declining. Nature Commun. 7, 10244 (2016). doi: 10.1038/ncomms10244

[4] Knoflacher, H. Zurück zur Mobilität! Anstöße zum Umdenken. Ueberreuter, Wien (2013)

[5] Sparkman, G., Howe, L., Walton, G. How social norms are often a barrier to addressing climate change but can be part of the solution. Behavioural Public Policy 5(4), 528-555 (2021). DOI: https://doi.org/10.1017/bpp.2020.42

How to cite: Nauen, C. E.: Art of hosting approaches with greater participation of scientists can support robust solutions for increased societal resilience, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4421, https://doi.org/10.5194/egusphere-egu23-4421, 2023.

EGU23-4443 | Posters on site | EOS4.1

Minerals as lenses to illustrate the relationships between Geology and colonialism 

Selby Hearth and Carrie Robbins

When the core ideas of Geology were being developed in the 19th century, geologists used colonial expeditions for transport, access, data, and -- critically -- specimens. Mineral specimens were sent from colonized and mined localities around the world to centralized collections in Europe and European settler states, forming diverse repositories of minerals, rocks, and fossils that geologists could then draw on without having to leave their home country. The accumulation of these specimens contemporaneously spurred the growth of museums and formed the collections at the heart of object-based pedagogy. As curators of these collections today, how can we use these specimens and their histories to illustrate these connections? This presentation will examine how the Bryn Mawr Mineral Collection is using mineral specimens in cataloging, display, and teaching to provoke reflection on this critical social dimension of our science. One of these strategies has been to recruit student research into mine sites and the provenance and provenience of individual specimens. Activating historical collections in this way helps make them relevant to today’s students. It also helps students recognize that geo-colonialism is not restricted to the past. Lithium, cobalt, and other rare minerals will be central to the production of batteries and anti-carbon technologies for the new “green economy” in the coming decades. It is important that mineral collections begin to use specimens to teach broader social histories of mining, extraction, and Western colonial relationships so that differential distributions of power are taken into account.

How to cite: Hearth, S. and Robbins, C.: Minerals as lenses to illustrate the relationships between Geology and colonialism, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4443, https://doi.org/10.5194/egusphere-egu23-4443, 2023.

Scientists remain citizens and human beings. As so, they keep their critical mind and have visions for society and opinions on related crucial issues. The climate and ecological crisis makes no exception and has become the subject of more and more discussions among scientific communities. The bond between scientific research and societal issues can be seen in the common practice of national funding agencies asking scientists to explicitly define the societal values of their research activities (the so-called “knowledge utilization”). On such occasions, scientists need to prove that their findings will bring parts of technical, scientific, social, or even political solutions to a range of stakeholders, including decision-makers. Such a peculiar position raises many issues. In democracies, scientists and other experts are usually asked to remain neutral and only provide scientific and technical knowledge to support decision-makers (i.e., governments) who will make the decision.

The question of neutrality has particularly animated scientific communities for decades. May we, as scientists, activate only the rational part of our brains when doing science and activate the emotional one when we return to our daily personal and civic life? Should we remain neutral at all costs? When "business as usual" means making the ecological and social crisis more profound, does the concept of neutrality even exist? Is that ethical if doing nothing means supporting "business as usual"? Or should we admit that this is neither doable nor desirable?

In this paper, we suggest that being neutral and inactive is neither doable nor desirable for the sake of science and society. First of all, scientists are people, and their actions cannot remain completely value-free or independent from societal influences. Instead, the notions of objectivity, scientific rigor, and transparency, which all make part of scientific integrity, may be much more relevant to define good research practices. As long as these practices are followed, many ways of communicating with peers, stakeholders, and the public sphere may be considered, from appeased recommendations to stakeholders all the way down to (illegal) civil disobedience, as those may only differ by their degree of engagement in reporting the same facts. To which the ethics of responsibility should be added: we must say what we know (Resnik and Elliot, 2016).

We collected several testimonies from scientists from the earth and climate sciences engaged in activism and civil disobedience. The description of the several types of intellectual trajectories will help us understand how scientists connect their values to science and how, at their scale, their vision helps them disseminate science to improve societies and reduce their impacts on global changes.

Resnik, D. B. and Elliott, K. C.: The Ethical Challenges of Socially Responsible Science, Accountability in Research, 23, 31–46, https://doi.org/10.1080/08989621.2014.1002608, 2016.

How to cite: Lassabatere, L., Kuppel, S., and Vitón, Í.: Engaged scientists and the question of neutrality and integrity: illustrative intellectual trajectories of geoscientists, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5456, https://doi.org/10.5194/egusphere-egu23-5456, 2023.

EGU23-5570 | ECS | Orals | EOS4.1

Decarbonising conference travel: testing a multi-hub approach 

Sabrina Zechlau, Stefanie Kremser, Andrew Charlton-Perez, Jadwiga Richter, Jose Santos, Julia Danzer, and Stefanie Hölbling

As the global research enterprise grapples with the challenge of a low carbon future, a key challenge is the future of international conferences. An emerging initiative which combines elements of the traditional in-person and virtual conference is a multi-hub approach. Here we report on one of the first real-world trials of a multi-hub approach, the World Climate Research Programme/Stratosphere-troposphere Processes And their Role in Climate (WCRP/SPARC) General Assembly held in Qingdao-Reading-Boulder during the last week of October 2022. Based on travel surveys of participants, we estimate that the multi-hub approach reduced the carbon footprint from travel of between a factor of 2.3 and 4.1 times the footprint when hosting the conference in a single location. This resulted in a saving of at least 288 tCO2eq and perhaps as much as 683 tCO2eq, compared to having the conference in one location only. Feedback from participants, collected immediately after the conference, showed that the majority (85%) would again attend another conference in a similar format. There are many ways that the format of the SPARC General Assembly could have been improved, but this proof-of-concept provides an inspiration to other groups to give the multi-hub format a try.

How to cite: Zechlau, S., Kremser, S., Charlton-Perez, A., Richter, J., Santos, J., Danzer, J., and Hölbling, S.: Decarbonising conference travel: testing a multi-hub approach, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5570, https://doi.org/10.5194/egusphere-egu23-5570, 2023.

Paul Crutzen’s concept of the Anthropocene in Nature in 2002 stressed that “a daunting task [lay] ahead for scientists and engineers to guide society towards environmentally sustainable management” and that “this will require appropriate human behaviour at all scales”. The proposal by the Anthropocene Working Group of the International Commission on Stratigraphy’s Subcommission on Quaternary Stratigraphy for an ‘Anthropocene Epoch’ with an isochronous mid-20th century start has been recently challenged by another group of researchers. Mindful of the diachronous impacts of human evolution, they favor a much longer and still ongoing ‘Anthropocene Event’.

In sync with IUGS goals to promote public understanding of the Earth and contribute to international policy decisions, the Anthropocene debate offers an unprecedented opportunity for the geoscience profession to become proactively relevant to the UN’s next-step vision for Planet Earth. Arguably, its 2015-2030 agenda of 17 Sustainable Development Goals each focused on a facet of society and the environment needs a more holistic successor with realistic thinking about sustainability, “one of the most overused and ill-defined words in conversations about the environment” in the view of Andrew Revkin at Columbia University’s Earth Institute. Ideally, the UN’s successor plan would be aligned with the interdependent subsystems of the Earth-Human System and propelled by transdisciplinary involvement of the sciences and humanities.

Echoing an observation by Stanley Finney and Lucy Edwards in GSA Today in 2016 that the terms Anthropocene and Renaissance have similar characteristics as “richly documented, revolutionary human activities”, an ‘Anthropocene Renaissance’ would highlight the need for greater harmony among and between environmental and societal movements. In this vision, the past-framed ‘Anthropocene Event’ underpins the future-framed ‘Anthropocene Renaissance’ as a boldly integrated effort to ‘protect our planet’, one of twelve commitments made by world leaders in 2020 at the UN’s 75th Anniversary Meeting. In a profile of the Anthropocene debate in The New York Times on 18 December 2022, the conclusion featured my interview: “I always saw it not as an internal geological undertaking but rather one that could be greatly beneficial to the world at large”. The UN’s ‘Summit of the Future: Multilateral Solutions for a Better Tomorrow’ will take place in New York City on 22-23 September 2024.

 

 

 

 

How to cite: Koster, E.: Defining the Anthropocene for the greatest good as an Event-based Renaissance, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6182, https://doi.org/10.5194/egusphere-egu23-6182, 2023.

EGU23-6356 | Posters on site | EOS4.1

Ma Terre en 180 Minutes: a transition support system to build decarbonization scenarios in the academic community. 

Nicolas Champollion and the Ma Terre en 180 Minutes team

A growing portion of scientists realized the need to not only alert about climate change, but also change their professional practices. A range of tools have emerged to promote more sustainable activities, yet many scientists struggle to go beyond simple awareness-raising to create concrete transition actions. This study proposed the use of a new game-based transition support system called " Ma Terre en 180 Minutes ", which is, to our knowledge, the first tool developed by and for the academic community. It has been designed to build scenarios of greenhouse gases (GHG) emissions reduction in the academic community, and present its deployment during the year 2021, including six hundred participants from 9 countries and 50 cities.

 

After the phase 1, called awareness, that aims to build a common scientific background about the context (global warming, its causes and consequences, planetary boundaries) and challenge (50% reduction of our carbon budget by 2030), the participants, with the phase 2 called role-playing, immerse themselves into fictional characters, to simulate the behavior of real research groups. Phase 1 and 2 are separated by a few days interphase helping participants to embody their fictional characters and be comfortable with the virtual research group they will simulate, as well as having time to perform their personal carbon footprint. Finally, an important final phase after the game-playing phase 2 take place to discuss, analyze and assess the results of phase 2.

 

Results show clear pathways for GHG reductions between 25 and 60%, and a median reduction of 46%. The alternatives allowing the greatest reduction are video communication tools (36%), followed by mutualization of professional activities and voluntary cancellation or reduction, thatrepresents 22 and 14% of reduction, respectively. The remaining 28% of reduction is composed by the use of trains as a transport alternative, the relocation of professional activities, the duration extension of some missions, etc… In addition, the analyses pointed out the importance of guided negotiations to bring out some alternatives such as relocation, local partners and computing optimization. An added value of this transition support system is that the information it collects (anonymously) will be used to answer pressing research questions in climate change science and environmental psychology regarding the use of serious games for promoting changes in attitudes and behaviors towards sustainability, and including broader questions on how network structures influence “climate behavior”, knowledge, and the governance of the commons.

How to cite: Champollion, N. and the Ma Terre en 180 Minutes team: Ma Terre en 180 Minutes: a transition support system to build decarbonization scenarios in the academic community., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6356, https://doi.org/10.5194/egusphere-egu23-6356, 2023.

EGU23-7063 | Posters virtual | EOS4.1

The evolving Code of Conduct at the National Institute of Geophysics and Volcanology of Italy: a participatory process to combine law compliance and geoethics principles 

Giuliana Rubbia, Daniele Bravi, Valeria De Paola, Sergio Gurrieri, Maria Valeria Intini, and Silvia Peppoloni

According to the current legislation of Italy (e.g., Law No. 165/2001) public organizations must have a code of conduct in place, which specifies and complements the General Code of Conduct for public employees, embedding issues that are typical for the specific context. 

The Authority aimed at disseminating a culture of integrity and legality, the Italian National Anti-Corruption Authority (ANAC), provided a set of directives over time that specifies key actors and procedures, drafting methods, and fundamental principles that the Code must contain.

In this framework, public research institutes are no exception. At the National Institute of Geophysics and Volcanology of Italy (INGV) an interdisciplinary working group with diverse experiences and profiles has been created and committed to reviewing the current code of conduct and proposing a new one.

The drafting process progressed through a thorough examination of fundamental principles and compliance with laws, on the one hand, and with an in-depth analysis of areas of application in the context of the institute and its activities. 

Once drafted, the first version has been proposed for provisional approval by the Board of Administrators (CdA), and submitted for stakeholder consultation.  INGV personnel commented on the first version, expressed their concerns, and proposed various amendments. These comments have all been addressed, partially or completely accepted, or refused; an updated version has been created and submitted for a further round of approval by the Independent Evaluation Body (OIV), a body assessing the performance, clearness, and integrity of the administrative action.

The values on which the Code is structured refer to four geoethical domains: 1) the individual dimension, which concerns the ethical action of each individual recipient of the Code in the context of his/her specific work activity; 2) the interpersonal/professional dimension, which refers to relationships with colleagues; 3) the societal dimension, which includes relations with all the various components of society; and d) the relationship with the natural environment, which includes actions aimed at minimizing negative impacts on ecosystems and promoting eco-sustainable behaviors. Moreover, the code benefits from the principles expressed in the European Code of Conduct for Research Integrity and the European Charter for Researchers.

At present, the Code contains both ethical and legal norms, i.e. both principles underpinning appropriate behaviors and rules, which if violated give rise to sanctions.  Code recipients are called to observe them in order to ensure workplace well-being, quality of research and services, prevention of corruption phenomena, compliance with the constitutional duties of diligence, loyalty, impartiality, care of the public interest, and achievement of INGV institutional goals. The Code will be updated according to the structure of a new General Code of Conduct to be issued by the Italian Government.

How to cite: Rubbia, G., Bravi, D., De Paola, V., Gurrieri, S., Intini, M. V., and Peppoloni, S.: The evolving Code of Conduct at the National Institute of Geophysics and Volcanology of Italy: a participatory process to combine law compliance and geoethics principles, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7063, https://doi.org/10.5194/egusphere-egu23-7063, 2023.

EGU23-7377 | Posters on site | EOS4.1

For a sustainable future: a survey about geoethics and 2030 Agenda among the Italian geosciences community 

Elena Egidio, Andrea Gerbaudo, Manuela Lasagna, Francesca Lozar, and Marco Davide Tonon

The annual Congress of the Società Geologica Italiana (SGI) and Società Italiana di MIneralogia e Petrologia (SIMP), held in Turin in September 2022 and dedicated to Geosciences for a sustainable future, has been the occasion to critically think on the role of the Geosciences for our society and planet, on the position geoscientists deserve and the role they must take in the formation of citizens, protection from natural hazards and preservation of cultural and natural heritage. In continuation of our previously published work Are we ready for a sustainable development? A survey among young geoscientists in Italy , the present study broadens the sample analyzed to include the entire Italian community of geoscientists and aims to highlight: 1) The relevance of the ethical aspects connected to the work of professionals and scholars, in accordance with the values of geoethics; 2) the most widely held views about the connections between the Earth Sciences and the 17 Sustainable Development Goals of the UN 2030 Agenda; 3) which initiatives have been put in place by Italian Earth Sciences departments on education for sustainability and which can be the best strategies for developing sustainability education related to geoscience issues. Based on 230 answers to a questionnaire with open and closed questions sent to the participants at the Congress, the results show that the Italian geocommunity has great awareness of the ethical implications of its work and research, in particular of the responsibility towards the environment; despite this consciousness, the average level of knowledge about the 2030 Agenda and its goals is still scarce. To fill this gap, the need for sustainability education initiatives in departments is recognized as urgent, as well as the use of inter- and transdisciplinary educational approaches that can train scholars and professionals capable of addressing the complex challenges of our time.

How to cite: Egidio, E., Gerbaudo, A., Lasagna, M., Lozar, F., and Tonon, M. D.: For a sustainable future: a survey about geoethics and 2030 Agenda among the Italian geosciences community, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7377, https://doi.org/10.5194/egusphere-egu23-7377, 2023.

This communication aims at presenting how transitions are being made at different organizational scales at INRAE (French National Research Institute for Agriculture, Food and Environment): (1) at the scale of a research lab through the perspective of a sustainable development contact person, (2) at the scale of a regional research centre through the perspective of the sustainable development regional manager, and (3) at the national and institutional level with the view of the sustainable development director of INRAE. The overall institutional context is first introduced to further develop viewpoints of the three persons involved on the on-going transitions, the strengths of the implemented approach, but also the points of attention. This communication aims at triggering exchanges on how to make sustainable development reach all organizational levels while ensuring a global coherence, and notably across all professions including administration staff, scientists, engineers, etc.

How to cite: Gauthier, L., Vidal, J.-P., and Carnet, A.: How to make a sustainable development approach successful across all scales of a research institute? Crossed views at INRAE, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7600, https://doi.org/10.5194/egusphere-egu23-7600, 2023.

EGU23-7601 | Orals | EOS4.1

Reducing environmental impact at NERSC (Bergen, Norway). 

Julien Brajard and Christine Due Sivertsen

NERSC is a non-profit research foundation established in Bergen (Norway) in 1986. Besides cutting-edge research in climate science, the NERSC has for a long time been very attentive to the working conditions, diversity, inclusion, and environmental impact of its activities.

In this poster, we will present the different efforts taken at the NERSC initiative to take the path of reducing its environmental impact, especially the GHG footprint, of its activities. We have divided the analysis into big compartments including the travels, the numerical computations, the field campaigns, and the premises. For each compartment, we are in the process to assess the GHG emissions, and some actions have already been taken to already minimize the impacts, for example, a travel policy, and opportunity campaigns.

In addition to the details of the work done by NERSC for reducing GHG emissions, we will reflect on challenges and problems encountered while taking those actions, some being general to the scientific or geoscience field (e.g., travel injunction), others being specific to NERSC (fundings, geographic location, low-carbon electricity).

Finally, we will draw perspective to the experience, and try to bring recommendations into the debate, such as a better inclusion of climate impact in the European research calls.

How to cite: Brajard, J. and Sivertsen, C. D.: Reducing environmental impact at NERSC (Bergen, Norway)., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7601, https://doi.org/10.5194/egusphere-egu23-7601, 2023.

EGU23-7612 | ECS | Orals | EOS4.1

My earth in 180 minutes: A transition support system for reducing the carbon footprint in Academia. Experimental design for evaluating its impact on academic practices 

Claudia Teran-Escobar, Nicolas Becu, Nicolas Champollion, Nicolas Gratiot, Benoit Hingray, Géremy Panthou, and Isabelle Ruin

Some practices embedded in academic culture (international conferences, scientific instruments...) are  important sources of greenhouse gases (e.g., van Ewijk & Hoekman, 2021). Although the scientific community have started to propose ways to reduce the impact of international conferences (e.g., Warner et al., 2022), collective efforts should be pursued to reduce the carbon footprint of the entire academic world. Serious games have been used in the encourage climate change attenuation practices (Fernández Galeote et al., 2021). Nevertheless, to our knowledge, the deployed evaluations have only measured the changes on knowledge and not on actual practices.

My Earth in 180 Minutes (ME180, https://materre.osug.fr/) is a collaborative role-playing game aiming at raising awareness, stimulating interactions in groups and constructing scenarios of professional carbon footprint reductions with multiple stakeholders. The game sessions place staff (researchers, technical and administrative staff, etc.) in a situation of social interaction in which each person plays two characters (inspired from real life observations) of a research team needing to reduce its carbon footprint by 50%. The game allows to build scenarios to reproduce as much as possible the complexity of interactions and the level of inequality existing within academic world. With 85 games played between November 2020 and June 2021, My Earth in 180 Minutes collaborative workshop has shown robust results, in particular Academia’s capacity to reduce its own carbon footprint and propose concrete alternatives: video communication, mutualization and reduction of professional activities (Gratiot et al., 2022).

This communication will describe the methods designed to a) evaluate the effectiveness of the serious game “My Earth in 180 Minutes” in academic practices and b) investigate the factors (e.g., career status, family engagements) that enable or constrain changes in academic practices.

The protocol for a future study is described. Participants working in French research centres (N = 970) will be recruited and randomly split in two groups: a) a group who will participate to the ME180 workshop, or b) control group using another approach for discussing about Academic carbon footprint. Participants will complete online surveys about their professional practices (air travelling, commuting ...) and about the psychological, institutional and, sociodemographic factors related to these practices (intention towards reducing professional air travelling, number of children). The surveys will be repeated six times over the 2 years of the study: before the experiment, one, 6, 12, 18 and 24 months after the beginning of the study. Data will be analysed by using mixed linear methods.

We expect that carbon footprint reduction and related practices would be more important in the ME180 group. Mediation and moderation analysis will be used to identify psychological, institutional and, sociodemographic factors (career status, intention to change practices) that may facilitate or block the transition of professional practices.

The previous deployments of “My earth in 180 minutes” help in identifying Academic transition paths (Gratiot et al., in revision). The present study will allow to assess the effects of ME180 in Academic carbon footprint reduction to provide insights about the obstacles and levers of carbon footprint reduction in academia.

How to cite: Teran-Escobar, C., Becu, N., Champollion, N., Gratiot, N., Hingray, B., Panthou, G., and Ruin, I.: My earth in 180 minutes: A transition support system for reducing the carbon footprint in Academia. Experimental design for evaluating its impact on academic practices, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7612, https://doi.org/10.5194/egusphere-egu23-7612, 2023.

EGU23-8072 | Orals | EOS4.1 | Highlight

Hydrogeoethical questions related to urban groundwater management: the case of Kabul city, Afghanistan 

Mohammad Salem Hussaini, Asadullah Farahmand, and Manuel Abrunhosa

Groundwater resources are largely invisible and unknown to most people. Hence, unauthorized appropriation of groundwater is not obvious, and its impacts are less evident. It can be said that it is an invisible geo-resource but its impacts and problems are visible to mankind, even if often its source is not recognized. Kabul, the capital of Afghanistan, is the fifth fastest-growing city in the world and rapid population growth and urbanization have created huge pressure on groundwater resources. As a result of a lack of surface water storage and the seasonal variability of river flows, Kabul is among the world's most water-stressed cities as it depends almost entirely on groundwater. The findings of scientific studies reveal that extensive groundwater depletion and degradation of groundwater quality in Kabul city is largely due to anthropogenic factors and it is likely to rapidly continue in the future, particularly in densely populated areas of the city. Here, ethics can play an important role because human behavior is among the main factors creating the problems. So, hydrogeoethical concepts can be assessed and discussed, especially for urban groundwater where human needs (social ethics) and environmental dynamics (environmental ethics) both should be respected. In this study, the most vital questions related to ethical aspects of groundwater management in Kabul city are extracted. To achieve the questions, the water ethics principles and ethical criteria were evaluated concerning the condition of groundwater and the society of Kabul city, as an exercise of applied hydrogeoethics. Finally, six questions are obtained as the result of this study. The response to these critical questions could be a key to solving many dilemmas related to groundwater management in an urban concept. It is recommended to groundwater managers and policymakers explore the answer to these questions and consider the findings in the policies, strategies, and regulations, particularly in urban regions.

The questions are as follows:

1) What is the level of contribution, obligation, responsibility, honesty, trust, and respect among geoscientists, and engineers related to groundwater management?

2) What kind of regulation is adequate for the management of over-abstraction urban groundwater; top-down or self-regulation or a mix of both?

3) How education and communication can shape moral motivation for city residents to better groundwater management?

4) What is the level of participation of public media (TV, radio, newspapers, etc.) in awareness-raising campaigns related to groundwater conditions?

5) Can groundwater abstraction from the deep aquifer (groundwater mining) be an ethical and sustainable policy concerning future generations and environmental ethics?

6) How consideration of gender equity and women's participation can be effective in the management of groundwater?

How to cite: Hussaini, M. S., Farahmand, A., and Abrunhosa, M.: Hydrogeoethical questions related to urban groundwater management: the case of Kabul city, Afghanistan, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8072, https://doi.org/10.5194/egusphere-egu23-8072, 2023.

EGU23-8173 | ECS | Posters on site | EOS4.1 | Highlight

The specific responsibility of geoscientists in the midst the climate and ecological crises: a need to address personal and institutional dissonances 

Odin Marc, Elodie Duyck, Laurent Lassabatère, Iñigo Viton, and Marthe Wens

The climate and ecological crises question the role and responsibility of scientists and scientific institutions as producers and conveyers of knowledge. Decades of thorough reporting, efforts at communication towards policy makers, and strong-worded scientific warnings, have not yet lead to policy changes significant enough to reduce greenhouse gas emissions and halt environmental degradation. This questions whether geoscientists and scientific institutions should remain distanced from the political and societal implications of their research work, or if on the contrary they have a responsibility to lead by example and to use their position to press for urgent action on the climate and ecological crisis. 

We argue that the failure of governments and international institutions to address these crises at the appropriate scale gives scientists and scientific institutions a responsibility to be more than mere producers of knowledge.  Indeed, doing “science as usual” while warning of the ever growing urgency to act on the climate and ecological crisis risks is widening the already-existing dissonance between, on the one hand, our stated raison d’être and discourses and on the other hand, our everyday practice and institutional mechanisms ; effectively undermining our impact on the broader society.

We first discuss the issue of scientific institutions and the scientific community at large not yet leveling with the urgency to address the climate and ecological crises. A prominent example is that despite repeated campaigns for universities to severe ties with the fossil industry, most  are still accepting sponsoring and research funding from fossil companies, which contributes to the legitimization of companies that have been and are still actively opposing effective climate action. While some universities are taking initiatives to limit carbon intensive behavior such as flying, serve plant-based food as a standard, stop accepting polluting companies on campuses, or include climate education in all curriculums, these are still individual initiatives, dependent on the voluntary mobilization from student and staff.

 We then argue that we, as geoscientists, can not only lead by example with individual changes to our lives, but can also have a strong impact when engaging in collective action, pressing our universities and governments to enact strong climate and environmental policies. Public engagement of universities, of other scientific institutions, and of scientists can amplify and legitimize the voice of the climate and environmental movements in a mutually beneficial science-society approach, notably because the former produce the very scientific knowledge empowering these movements.  We propose to discuss recent examples, including from our own experience, of the impact of scientists engaging in demonstrations and civil disobedience as part of environmental groups, at the ethical level, but also regarding consequences within and outside of academic circles.

How to cite: Marc, O., Duyck, E., Lassabatère, L., Viton, I., and Wens, M.: The specific responsibility of geoscientists in the midst the climate and ecological crises: a need to address personal and institutional dissonances, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8173, https://doi.org/10.5194/egusphere-egu23-8173, 2023.

EGU23-8259 | Posters on site | EOS4.1

Geoethics values clarification: A playable poster 

David Crookall and Pimnutcha Promduangsri

Values underlie geoethics and geoscience, especially climatology.  Can we understand or build geoethics without reference to values?  Are values and geoethics driven by beliefs, or should values remain unchanged despite changing beliefs?  Those are some of the questions that we may ask when considering ethics in life, in the geosciences and in climate change and action.  Values include honesty, compassion, quality, patience, objectivity, truth, respect, individualism, justice, power, peace and beauty.  How are these related to geoethics?  Often an ethical dilemma stems from two or more underlying value conflicts, such as individual identity and social value.  It is not easy to understand the principles and dynamics of such relations.

One way into this quagmire is by using a values clarification exercise or game (VCE or VCG).  A VCE can be a useful geoethics literacy tool to help people explore the complexities of such relationships, to allow them to express their own ideas, to confront their ideas with those of others and to gain a rich understanding of their own values that underlie geoethics.  Undorf and colleagues (eg, https://doi.org/10.5194/egusphere-egu22-12732, https://doi.org/10.1007/s10584-022-03435-7) have adopted a philosophical approach.  We take an easier approach, that of interactive, participatory gaming.

We have designed and used VCEs and VCGs in a variety of cultural and social settings and with encouraging results.  Our poster will outline our prior experience and allow you to participate, albeit superficially, in a VCE.  Please come to see us during the poster session, and be sure to bring along one or two friends so that you can play; three players is better than two.  Also bring some paper and a pen.

How to cite: Crookall, D. and Promduangsri, P.: Geoethics values clarification: A playable poster, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8259, https://doi.org/10.5194/egusphere-egu23-8259, 2023.

EGU23-8402 | ECS | Orals | EOS4.1

The share of research infrastructure in comprehensive greenhouse gas budget for five French Earth and Space Science laboratories 

Odin Marc, Sylvain Biancamaria, Solene Derrien, François Gheusi, Jürgen Knödleser, Sylvain Kuppel, Marion Maisonobe, Arnaud Mialon, Pierrick Martin, Florian Pantillon, Luigi Tibaldo, and Florence Toublanc

To maintain global warming below 1.5°C the last IPCC report indicates global greenhouse gas (GHG) emissions should be reduced by 45% and 80% before 2030 and 2050, respectively, reaching an average of 2 tCO2e.pers-1.yr-1 on Earth. Although responsibilities vary, substantial reductions must be implemented across all aspects of society including academia. It can even be argued that, given its role in informing and alerting the public about climate and ecological change, the scientific community should have a leading role and demonstrate exemplarity in terms of reducing its environmental impact.

Here, we present a broad-scope GHG budget of five laboratories of the Observatoire Midi-Pyrénées in France, in 2019. The studied laboratories comprise 90 to 260 staff members each, with study fields encompassing the solid Earth and the environment, the superficial biosphere, oceanography and glaciology, atmospheric physics and chemistry, as well as astronomy and astrophysics.

To assess GHG emissions, we follow standard procedure (see Mariette et al., Environ. Res.: Infrastruct. Sustain., 2022) in which anyactivity data’ quantifying the usage of a given resource (e.g., in kWh of electricity, or km travelled by aircraft) is multiplied with an appropriate emission factor’ quantifying the unitary carbon footprint of the resource (e.g., electricity production or air-travel). The quantified budget thus includes infrastructures usage, professional travel and expenses and an estimation of the GHG footprint of research infrastructures, in particular scientific satellites. For the latter, we adapted the methodology of Knödleser et al. (Nature Astronomy, 2022), in which the GHG footprint is estimated based on the launch mass or cost of the mission and the share attributable to a given lab depends on the fraction of world author affiliated with the lab who have published articles referring to the satellite, as extracted from the Web of Science database.

We find that emissions related to the lab facilities (electricity, heating, air conditioning and waste) and to individual habits (commuting and lunch meals) both reach about 1 tCO2e.pers-1.yr-1. Unsurprisingly, professional trips significantly contribute to the overall budget (2-6 tCO2e.pers-1.yr-1) and are largely dominated by long-haul air travel. However, services and equipment equally contribute with more than 3-5 tCO2e.pers-1.yr-1. These numbers vary between the studied labs but higher (lower) values for services and equipment tends to compensate for lower (higher) values for professional trips. Furthermore, for three out of five laboratories observational data from research infrastructures represents the largest share of the emissions, with about 5-10 tCO2e.pers-1.yr-1. Although this last estimate is subject to large uncertainty and shows discrepancies between research fields, it suggests that current GHG budget should include at least a first order estimate of the footprint of research infrastructures and adapt reduction strategies accordingly.

How to cite: Marc, O., Biancamaria, S., Derrien, S., Gheusi, F., Knödleser, J., Kuppel, S., Maisonobe, M., Mialon, A., Martin, P., Pantillon, F., Tibaldo, L., and Toublanc, F.: The share of research infrastructure in comprehensive greenhouse gas budget for five French Earth and Space Science laboratories, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8402, https://doi.org/10.5194/egusphere-egu23-8402, 2023.

EGU23-8683 | Orals | EOS4.1 | Highlight

The Knowledge Hub on Sea Level Rise and the science-based European Seas assessment reporting 

Nadia Pinardi, Bart van den Hurk, Jose A. Jimenez, Gundula Winter, Giulia Galluccio, Sandy Bisaro, Angelique Melet, Roderick van de Wal, Kristin Richter, Jan-Bart Calewaert, Bernd Bruegge, Lavinia G. Pomarico, Michael Depuydt, Thorsten Kiefer, and Petra Manderscheid

Nine European countries under the umbrella of the Joint Programming Initiatives on Climate (JPI Climate) and on Oceans (JPI Oceans) have set up a joint Knowledge Hub on Sea Level Rise. The ambition is to provide easy access to usable knowledge on regional-local sea level change in Europe, regularly updated as a series of periodic assessments. It will complement existing global and national assessments by providing additional geographical and contextual detail, tailored to regional, national and European policy development and implementation.

As its key product, it will deliver by the end of 2023 its first European Assessment Report on Sea level rise hazards and impacts, co-designed with European Sea stakeholders. The co-design framework is based on consultation workshops, questionnaires and a final Conference in Venice that enabled to discuss at large the regional and local end-user needs.

Based on the latest available science provided by  the IPCC AR6 WGI and II reports and using the most advanced knowledge on sea level rise from European services and research done at the national level, the Assessment report will allow to downscale to the European Seas the SLR impacts and devise adaptation strategies. We will present the user needs that were revealed by the stakeholder consultations and plan to provide a peek into the content of the first draft of this first Assessment Report.

How to cite: Pinardi, N., van den Hurk, B., Jimenez, J. A., Winter, G., Galluccio, G., Bisaro, S., Melet, A., van de Wal, R., Richter, K., Calewaert, J.-B., Bruegge, B., Pomarico, L. G., Depuydt, M., Kiefer, T., and Manderscheid, P.: The Knowledge Hub on Sea Level Rise and the science-based European Seas assessment reporting, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8683, https://doi.org/10.5194/egusphere-egu23-8683, 2023.

Local climate change risk assessments and climate resilient adaptation are best supported by a quantitative integration of physical hazards, exposures and vulnerabilities that includes the characterization of uncertainties. However, it is challenging to take into account the complex information of climate change projections and uncertainties in participatory risk assessments with decision-makers. We propose to use Bayesian Networks (BNs) for this task. Bayesian Networks are a cutting-edge integrated modelling approach for combining qualitative and quantitative knowledge in uncertain and complex domains, such as climate change impacts on water. To quantify potential future hazards of climate change on water, it is state-of-the-art to rely on multi-model ensembles to integrate the uncertainties of both climate and impact modelling. At the same time, local expert knowledge needs to be integrated in local climate change risk assessments. We show how to integrate freely-available output of multiple global hydrological models into BNs, in order to probabilistically assess risks for water supply. To this end, a roadmap to set up BNs and apply probability distributions of risk levels under historic and future climate and water use in a participatory manner was co-developed with water experts from Spain and the Maghreb. Multi-model information on hydrological variables was computed by three global hydrological models driven by the output of four global climate models for four greenhouse gas emissions scenarios. The output of projected relative changes of hydrological hazards was pre-processed using MATLAB, taking into account local information on water availability and use, to set up the BN. Results show that the method is useful for probabilistically computing climate change impacts on water stress and to assess potential adaptation measures in a participative process with stakeholders and decision-makers. Local water experts positively evaluated the BN application for local climate change risk assessments. While requiring certain training, the presented approach is suitable for application in the many local risk assessments necessary to deliver efficient and successful climate resilient adaptation.

How to cite: Kneier, F., Woltersdorf, L., and Döll, P.: Participatory Bayesian Network modelling to assess climate change risks and adaptation regarding water supply: integrating multi-model ensemble hazard information and local expert knowledge, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8861, https://doi.org/10.5194/egusphere-egu23-8861, 2023.

EGU23-8882 | Posters on site | EOS4.1

How to reduce the carbon footprint of Earth and Space Science? Potential strategies based on a comprehensive greenhouse gas budget for five French labs 

Florian Pantillon, Sylvain Kuppel, Sylvain Biancamaria, Solene Derrien, François Gheusi, Jürgen Knödlseder, Marion Maisonobe, Odin Marc, Arnaud Mialon, Pierrick Martin, Luigi Tibaldo, and Florence Toublanc

To maintain global warming below 1.5°C the last IPCC report indicates global greenhouse gas (GHG) emissions should be reduced by 45% and 80% before 2030 and 2050, respectively, reaching an average of 2tCO2e.pers-1.yr-1 on Earth. Recent estimates of the carbon footprint of universities and research centers accounting for indirect emissions often exceed 10tCO2e.pers-1.yr-1.

Here we find similar or higher values (10-30tCO2e.pers-1.yr-1) for the year 2019 for five research labs encompassing the solid Earth and the environment, the superficial biosphere, oceanography and glaciology, atmospheric physics and chemistry, and astronomy and astrophysics. These values are derived through a common procedure (see Mariette et al., 2022) in which any activity data quantifying the usage of a given resource (e.g., in kWh or km) is multiplied by an appropriate emission factor quantifying the unitary carbon footprint of the resource (e.g., electricity production or air travel). Our budget quantifies the share of emissions from local facilities (about 1tCO2e.pers-1.yr-1), lunch meals and commuting (about 1tCO2e.pers-1.yr-1), professional trips (2-6tCO2e.pers-1.yr-1), services and equipment (3-5tCO2e.pers-1.yr-1), and the use of observational data from research infrastructures, in particular scientific satellites (up to 10tCO2e.pers-1.yr-1; derived similarly to Knödlseder et al., 2022).

These numbers imply radical changes to make scientific activity sustainable and have strong implications on potential strategies to reduce GHG emissions. For example, a predominant discussion in the literature in the past years focused on avoiding air travel. However, in our case, shifting all national travels to train or halving the number of plane trips would reduce the total emissions by a fraction only. Similarly, any strategy targeting local building efficiency or individual habits will little influence the budget. In contrast, reducing or changing practice for services and equipment may have stronger impact but requires collective thinking, especially for research infrastructures that are planned and managed at national and international levels.

The sheer magnitude of our GHG emissions questions the degree of reduction that can be achieved without redirection of scientific activity. We present and discuss examples of changes such as shifting to interdisciplinary research including social sciences, focusing on archived data, relocating field work, or engaging more with students and society.

How to cite: Pantillon, F., Kuppel, S., Biancamaria, S., Derrien, S., Gheusi, F., Knödlseder, J., Maisonobe, M., Marc, O., Mialon, A., Martin, P., Tibaldo, L., and Toublanc, F.: How to reduce the carbon footprint of Earth and Space Science? Potential strategies based on a comprehensive greenhouse gas budget for five French labs, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8882, https://doi.org/10.5194/egusphere-egu23-8882, 2023.

EGU23-9299 | ECS | Orals | EOS4.1

From informal to institutional science-society-policy interactions: Introducing a climate advisory board in Frankfurt, Germany 

Georg Sebastian Voelker, Ralf Becherer, Carmen Junge, and Thomas Seifert

Climate change may be the most severe crisis humanity has faced to date. Both the social and natural sciences have well understood the causes and effects of climate change as well as the possible mitigation and adaptation measures. However, implementations of both mitigation and adaptation measures generally fall behind the goals defined by the Paris agreement.

With increasing political awareness and progressing federal climate protection legislation in Germany communal politics is facing the challenge of charting explicit paths to net carbon neutrality. Due to diverse social and geographic settings as well as different existing infrastructures solutions have to be tailored to the local conditions. Local climate advisory panels are a common and if well constructed an effective way to support the local administration in the necessary transformation.

Here we report on the successful efforts lead by the local group of the Scientists for Future in Frankfurt, Germany, to aid the city hall in establishing a communal climate advisory panel. Early stakeholder communication, broad alliances with local climate protection initiatives and the shared experience of the Scientists for Future network were key to successfully establish an institutionalized science-society-policy interface to permanently support local climate action activities.

How to cite: Voelker, G. S., Becherer, R., Junge, C., and Seifert, T.: From informal to institutional science-society-policy interactions: Introducing a climate advisory board in Frankfurt, Germany, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9299, https://doi.org/10.5194/egusphere-egu23-9299, 2023.

EGU23-10073 | Posters virtual | EOS4.1

Teaching Geosciences through practical activities to enhance global citizenship education in schools with a high dropout rate 

Ester Piegari, Giovanni Camanni, Daniela Flocco, Maurizio Milano, Nicola Mondillo, and Umberto Riccardi

Most students living in disadvantaged areas do not trust that their school education will have much bearing on their future and become disaffected from school as early as in lower secondary school.

We here report the results of teaching Geosciences through several practical activities carried out in suburban schools characterized by a high dropout rate. The lectures were given in the framework of the STEM project Next Land, which has the overarching goal of instilling interest towards scientific topics into young students and promoting the role of scientific education for sustainable development.

We propose a sequence of four laboratory activities on the subject of natural calamities (e.g. earthquakes and tsunamis), which are based on the use of both manual and IT skills.

The didactical experimentation has been conducted on 21 seventh-grade classes (age ~12) involving about 350 students from the area of Naples (Southern Italy). The final aim of the teaching is to test the potential of the Geosciences in generating attitudes and behaviours of solidarity and responsible global citizenship.

All the proposed activities try to make students aware that they are part of a connected global system, therefore through these lectures we attempt to help these young students to put in perspective their local reality in a larger one.

How to cite: Piegari, E., Camanni, G., Flocco, D., Milano, M., Mondillo, N., and Riccardi, U.: Teaching Geosciences through practical activities to enhance global citizenship education in schools with a high dropout rate, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10073, https://doi.org/10.5194/egusphere-egu23-10073, 2023.

Existential and Global Catastrophic Risk, defined by Beard et al 2020 as risk that may result in the very worst catastrophes “encompassing human extinction, civilizational collapse and any major catastrophe commonly associated with these things.” As such, it has been the topic of work by many philosophers as we move into a world where humans have more and more power over the world around us.

However, geoscientists have typically neglected the study of these risks, and have in turn been neglected in the field of existential risk studies. I will discuss the ethical importance of reducing existential risk from a variety of different ethical frameworks, and how this links to the concepts in geoethics. I will then discuss some of the opportunities for geoscientists to contribute to the reduction of these risks, including some of the work that has been done by geoscientists to identify and reduce existential risk and increase civilisational resilience, as well as how methodological expertise of different geoscience disciplines can contribute to the growing corpus of theoretical work around existential risk.

How to cite: Futerman, G.: The Ethics and Role of Geoscientists in Existential Risk Studies, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10097, https://doi.org/10.5194/egusphere-egu23-10097, 2023.

Minerals occupy a unique position as specimens yielding scientific information, objects with aesthetic and monetary value, and substances necessary for modern society. Aside from minerals in industrial use, a broad range of people are interested in minerals such as geologists, gemologists and jewelers, and people involved in minerals as collectors’ items including miners, dealers, private and institutional collectors, curators -- even art collectors and anthropologists. Traditionally, we have taken the extractive nature of these minerals for granted with little discussion of where and how they are obtained.

Adherence to legalities, disclosure of information, and personal and institutions responsibility are among ethical considerations. Legal considerations include how a mineral specimen is obtained in its initial extraction, its movement through opaque supply chains, export and import requirements, and ownership transfer. Disclosure issues range from curators and institutions maintaining and relaying accurate information about a mineral’s authenticity, sourcing, and history. What ethical responsibilities do individuals and institutions possess to ensure acquisition policies that address these issues? And, finally, as mineral extraction becomes a more pressing issue in the world’s move from a fossil-fuel economy, where does ethics lie in educating the public in the role minerals play in the environment and society?

Some of these questions raise issues which, in their complexity, have no apparent or easy solution. This paper presents the results of a literature survey on ethics of mineral specimens and raises questions for geoscientists.

How to cite: Eriksson, S.: Things we just don't talk about:  ethics in mineral collection, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10191, https://doi.org/10.5194/egusphere-egu23-10191, 2023.

EGU23-10946 | Posters on site | EOS4.1

Research in Volcanology: where, when, and by whom? A global bibliometric analysis 

Susanna F. Jenkins, Geoffrey A. Lerner, George T. Williams, Elinor S. Meredith, and Jenni Barclay

The global and transdisciplinary nature of volcanology means that research takes place across institutions in a wide variety of locations around the world. The concentration of volcanic activity within certain regions means that researchers frequently conduct research outside their own borders. Collaboration between international and local researchers has the potential to produce mutual benefit and improve research. For local scientists, international collaboration can provide niche expertise that may not be currently available in the region where the volcano is located, in addition to resources, analyses, or equipment. For international researchers, in addition to different scientific perspectives, collaboration with local scientists can provide vital knowledge of local and regional information, access to field sites, and greater research relevance to the communities and organizations the research is often intended to benefit.

Despite these noted benefits, there is often a lack of inclusivity of local scientists in international research. In this study we use a bibliometric approach to understand who is doing and leading volcanic research, and in which countries the research is taking place. We assessed the metadata of ~24,000 volcanological works from 1901-2021 with 768 volcanoes identified across 68 countries. Our evaluation of affiliations shows that 40% of articles that name a volcano do not include any authors affiliated with the volcano’s country. We also look at case studies of island territories to explore to what extent local scientists are involved in doing research compared to the mainland or foreign countries. We find that only 23% of studies on volcanoes located on island territories have an author affiliated with the territory. Our assessment of bibliometric data provides insights and support for ongoing conversations on the inclusiveness of international research, both spatially and temporally, and can be used to identify geographical areas for improvement, as well as trends in inclusion and leadership.

How to cite: Jenkins, S. F., Lerner, G. A., Williams, G. T., Meredith, E. S., and Barclay, J.: Research in Volcanology: where, when, and by whom? A global bibliometric analysis, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10946, https://doi.org/10.5194/egusphere-egu23-10946, 2023.

EGU23-11580 | Orals | EOS4.1

Geoethics: hammering out an interdisciplinary conversation 

Bethany Fox, Kate Dawson, Vicki Trowler, Sophie Briggs, Ruth Massey, Alexandra Fitzsimmons, Tania Marshall, Christina Riesselman, and Anna Davidson

Geoethics is not just a matter of geoscience, but involves complex transdisciplinary concerns with social, economic and cultural implications. Because of this, both geoethicists within geosciences and those working in social sciences and humanities are increasingly calling for dialogue across disciplinary silos. Drawing from our work on the British Academy funded interdisciplinary project, ‘Mining for Meaning: the Geoethics of Extractive Industries,’ we trace out what an interdisciplinary engagement with Geoethics might look like. As an earthly ethics that necessarily stretches beyond geological considerations to consider the socio-natural, cultural-spiritual and political-economic, any engagement with Geoethics demands conversations that bring geoscientific understandings into more explicit dialogue with ideas from the social sciences and the geohumanities (though not exclusively). Acknowledging the very real challenges of doing interdisciplinary work - from distinct understandings about research, knowledge and results, to disciplinary-specific technical terminology - we set out the core ideas underpinning Geoethical approaches in these domains. This lays important groundwork for crafting meaningful and indeed ethical conversations that stretch across these disciplines, but crucially, avoids the mining of other disciplines for useful concepts and metaphors, without due regard for their context, history and technical meaning – a form of disciplinary extractivism in itself. Animated by this anti-extractivism, the paper presents a reading of how the earth, ethics, knowledge and practices are understood from within the geosciences, social sciences and geohumanities respectively, charting out what we hope to be a useful frame of reference for working across these disciplines. We then use this analysis as the bedrock for discussing the potential of cross-disciplinary conversation. By critically responding to the relative strengths, limitations and offerings of each discipline’s conceptualisation of geoethics, we bring to the fore important interdisciplinary frictions, overlaps and potential collaborative directions. Taken together, we suggest that this two-part analysis offers scope for crafting meaningful conversations necessary for an interdisciplinary Geoethics. 

How to cite: Fox, B., Dawson, K., Trowler, V., Briggs, S., Massey, R., Fitzsimmons, A., Marshall, T., Riesselman, C., and Davidson, A.: Geoethics: hammering out an interdisciplinary conversation, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11580, https://doi.org/10.5194/egusphere-egu23-11580, 2023.

EGU23-11656 | Orals | EOS4.1

Traveling for academic research : patterns, determinants and mitigation options 

Olivier Aumont, Tamara Ben Ari, Jérôme Mariette, Laurent Jeanneau, Aymeric Spiga, Gaelle Lefort, Philippe-e Roche, Alexandre Santerne, and André Estevez-Torres

In the midst of climate change, academic travels - one salient aspect of the carbon footprint of research activities - are at the center of a growing concern. Mitigation options often focus on two dimensions : (i) decreasing the frequency of attendance to conferences and (ii) modal shift in transport. Here, we analyze professional travel in academia from a unique database compiling about 100 000 travels from about 150 research labs across a large array of disciplines and localities in France to detail the structure, patterns and heterogeneity of national and international research travels for research purposes. We estimate the mitigation potential of a series of options encompassing but not limited to institutional options. We show that, if short distance traveling (typically below 1000 km) are largely dominant in number, their relative mitigation potential via modal shift is small (i.e., below 15%). On the other hand, long distance traveling, which is often associated with international collaborations or field work hold a much larger mitigation potential but question the very nature of research activities. We propose ambitious sobriety options to robustly decrease travel-induced GHG emissions in academia and discuss their acceptability in the context of the French public research system.

How to cite: Aumont, O., Ben Ari, T., Mariette, J., Jeanneau, L., Spiga, A., Lefort, G., Roche, P.-E., Santerne, A., and Estevez-Torres, A.: Traveling for academic research : patterns, determinants and mitigation options, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11656, https://doi.org/10.5194/egusphere-egu23-11656, 2023.

EGU23-12019 | ECS | Posters on site | EOS4.1

Development of a Web Based Decision Support System to Provide Relevant Climate Indicators for Climate Change Adaption 

Lorenz König, Mike Teucher, Katrin Ziegler, Daniel Abel, Torsten Weber, Heiko Paeth, and Christopher Conrad

The African continent faces various challenges and numerous risks due to current and future climate change. To strengthen the resilience of West African societies in the sectors of agriculture, food security, water and risk management, adaption measures need to be implemented in time. In the WASCAL-LANDSURF project, an earth system model for West Africa is developed to enable high-resolution regional climate change information. The obtained data must be accessible to the public so that interested stakeholders and smallholders can incorporate them into their decision-making processes.
To realize this, a web based spatial decision support system (SDSS) is developed with state-of-the-art open-source technologies to give information on climate change as well as relevant cross-sector indicators. For successful co-development, stakeholder workshops were held to identify important key functionalities and indicators that need to be implemented. The SDSS will be multilingual and easy to use to ensure an extensive range of applications. Users will have the possibility to familiarize themselves with the Web Portal by means of different guides in order to ease the entry into the SDSS. The current prototype supports map and diagram visualization and selection of various indicators and climate data, as well as query functionalities for different West African regions. Many other functionalities, such as the possibility to download data and statistical outputs of selected indicators, will be integrated soon. The final web portal will give users the opportunity to include climate indices in a simple and clear way into their decision-making process to strengthen their resilience towards climate change.

How to cite: König, L., Teucher, M., Ziegler, K., Abel, D., Weber, T., Paeth, H., and Conrad, C.: Development of a Web Based Decision Support System to Provide Relevant Climate Indicators for Climate Change Adaption, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12019, https://doi.org/10.5194/egusphere-egu23-12019, 2023.

EGU23-12106 | Orals | EOS4.1

Taking Stock of Greenhouse Gas Emissions in the Geosciences: an Example from GFZ Potsdam 

Christoph Sens-Schönfelder, Friedhelm von Blanckenburg, and Knut Kaiser

The basis of all serious efforts to reduce greenhouse gas emissions is an inventory of the emissions caused by the various activities of an organisation. The Greenhouse Gas Protocol provides the guideline for establishing such an inventory. The German Research Centre of Geosciences GFZ Potsdam used these guidelines to estimate its greenhouse gas emissions for 2019. Besides the estimation of quantities (e.g. travel distances or hotel nights) which is an administrative challenge, the specific emissions per unit of quantity -- the Global Warming Potential -- play a crucial role. Unequivocal accounting of emissions from construction work is another task of great complexity.  A compilation and standardisation of these values within the research community would greatly simplify the compilation of GHG inventories and help to improve their comparability. Controversy inevitably will arise regarding the design of mitigating measures, like purchase of electricity and heat from renewable sources (which generates extra costs) the compensation of emissions (of which the effectiveness is contested), and even to shifting scientific activities away from those with high greenhouse gas footprints (which may conflict with scientific needs). Building awareness for emissions caused by academic activities and careful communication of mitigation options comprise the first necessary steps en route to low (or net-zero)-emission science.

How to cite: Sens-Schönfelder, C., von Blanckenburg, F., and Kaiser, K.: Taking Stock of Greenhouse Gas Emissions in the Geosciences: an Example from GFZ Potsdam, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12106, https://doi.org/10.5194/egusphere-egu23-12106, 2023.

EGU23-12452 | ECS | Orals | EOS4.1 | Highlight

The ethics of volcano geoengineering 

Lara Mani, Mike Cassidy, and Anders Sandberg

Volcano engineering is the practice of altering the state of volcanic systems and/or volcanic eruptions to exploit them or mitigate their risk. Past and current examples of volcano engineering are limited but include drilling crater walls to drain volcanic lakes, channeling and bombing lava flows, siphoning off CO2 rich volcanic lakes, and cooling lava flows with seawater. There have also been several incidental examples of drilling into magma reservoirs in search for geothermal resources in Hawaii, Iceland, and Kenya. While not causing anything more damaging than the loss of drill bits or forcing the use of alternative holes, this demonstrates that humans are increasingly able to reach volcanic plumbing systems. As the pursuit of high temperature and enhanced geothermal energy increases as the world strives for renewable energy and critical metal resources, it is also likely that such contacts will become more common. We must accept, therefore, that despite the controversial nature of this topic, geoengineering of volcanic systems is an inevitable consequence of such exploration in the coming century. Since we possess the technological and engineering potential to perturb volcanic systems, the question we ask here is, should we? Do we have the scientific knowledge to do so? What are the potential benefits to future humanity? And, what are the ways it could do more harm than good? We highlight that while volcano geoengineering has significant potential benefits, the risks and uncertainties are too great to justify its use in the short term. Even if we do not decide to conduct volcano geoengineering, we believe there is a strong ethical case to support research into the efficacy and safety of volcano geoengineering going forwards. In this work, we lay out a series of protocols and practices based on the ethical arguments to be followed should humanity decide to conduct volcano geoengineering in the future.

How to cite: Mani, L., Cassidy, M., and Sandberg, A.: The ethics of volcano geoengineering, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12452, https://doi.org/10.5194/egusphere-egu23-12452, 2023.

EGU23-13681 | ECS | Orals | EOS4.1

Engaging stakeholders for the co-creation of Climate Services. Beyond ERA4CS INDECIS project  

Jon Xavier Olano Pozo, Anna Boqué Ciurana, and Enric Aguilar

INDECIS (Integrated approach for the development across Europe of user-oriented climate indicators for GFCS high-priority sectors: agriculture, disaster risk reduction, energy, health, water, and tourism) was a project part ERA4CS, an ERA-NET initiated by JPI Climate, and funded by FORMAS (SE), DLR (DE), BMWFW (AT), IFD (DK), MINECO (ES), ANR (FR) with co-funding by the European Union Grant 690462). INDECIS main produced different outcomes, such as software packages, improved datasets and a large number of scientific papers (see www.indecis.eu). 

 

Even though INDECIS formally ended in July 2021, the knowledge gained continues to pay off. This communication will synthetically show how we took advantage of the methodology for the engagement of stakeholders developed in INDECIS (Font et al. 2021). The co-creation methodology developed in the frame of INDECIS has served as a starting point for the development of further research, transfer, and empowerment actions of stakeholders for decision-making related to climate change in four main axes: in research, in leading international research and transfer projects in collaboration with industry, in local projects developed in partnership with industry, users and administration and, knowledge transference to high schools, bachelor degree and technical training to professionals. 

 

The research has continued through a doctoral dissertation based on co-creating a climate service for surfing (see Boqué Ciurana, 2022). It is also continued by developing more indices for tourism and tourism sites to face climate change effects through mitigation measures in the TURLIT-ODS project (see: http://turlit.eu). This project is a local scale project where with users, private actors, and administration, we try to define the optimal conditions to develop sport water activities in Calafell, Costa Daurada, Spain. 

 

With the industry, in collaboration with a private organization, we engage stakeholders in the infrastructure sector to co-define climate risk indices to manage risk and investments. In this project, through co-creation workshops developed with local agents from both the company (technical) and the administration and other sectorial actors, indices are being computed to assess the climate risk of mobility infrastructures (railways and highways). 

 

The co-creation methodology has been adapted to develop high school co-creation processes to empower young people with tools to fight climate change and misinformation (see EMPOCLIM project: http://www.empoclim.cat ). In the same way, the Geography, Sustainability, and Territorial Analysis bachelor at the Rovira i Virgili University, offers a subject (6 ECTS) to develop essential skills and competences for developing climate services based on the engagement of local stakeholders and co-creation. 

 

Last but not least. Updating the quality control and data homogenization software has allowed the development of training for NMHs in Colombia, Peru, and Chile in the frame of the ENANDES project. In this training, we added lectures and practices to capacity-building staff in co-creating climate services with local users. 

 

How to cite: Olano Pozo, J. X., Boqué Ciurana, A., and Aguilar, E.: Engaging stakeholders for the co-creation of Climate Services. Beyond ERA4CS INDECIS project , EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13681, https://doi.org/10.5194/egusphere-egu23-13681, 2023.

EGU23-13694 | Orals | EOS4.1

Reducing the carbon footprint of a public research laboratory in Geosciences. Assessing a reduction strategy built with laboratory members after a 3-year experimentation 

Thierry Pellarin, Nicolas Champollion, Nicolas Gratiot, Claudia Teran-Escobar, Isabelle Ruin, Geremy Panthou, Benoit Hingray, Gilles Delaygue, Eliot Jager, Alexis Lamothe, Guillaume Piton, Guillaume Evin, Juliette Blanchet, Nathalie Philippon, Armelle Philip, Patricia Martinerie, and Ghislain Picard

The Institute of Environmental Geosciences (IGE) is a public research laboratory in Earth and Environmental Sciences with a staff of about 300 people, which conducts research on climate, the anthropisation of our planet and environmental risks, combining glaciology, hydrology, oceanography, mechanics, atmospheric sciences and human sciences. An important part of its activity consists of field experiments in remote sites (Antarctica, Asia, South America, Africa), numerical simulations using significant computer resources (several million CPU hours/year), using expensive and sometimes energy intensive scientific equipment (e.g. 170 m² of cold rooms).

In 2019, the laboratory collectively decided to adopt a strategy to reduce its Carbon Footprint (CFP) by 7% per year in order to achieve a 50% reduction by 2030 and thus to comply with the objectives of the Paris Agreement. The first CFP budget (2018 and 2019, using the GES1point5 tool) showed a predominance of emissions from professional travels (~640 tCO2e out of 1850 tCO2e, i.e. 2.6 tCO2e/person). In this context, the strategy consisted in defining CO2 budgets for each of the 8 research teams of the IGE on the basis of the 2018/2019 emissions, imposing a 10% reduction per year from 2020. Given the pandemic in 2020 and 2021, the reduction targets for professional travel were easily achieved (-81% and -64%) and the reduction in 2022 was -39% compared to 2018/2019 instead of the targeted -27%.

For all emission items (commuting, professional travel, heating, electricity, digital computing, purchasing, refrigerants), the reduction was -45% in 2020, -30% in 2021 and -15% in 2022. To consider the evolution of the number of people in the laboratory (and in the teams), the mean individual CFP has been defined as the ratio between the CO2 emissions and the number of people in the laboratory. The IGE's mean individual CFP was 7.22 tCO2e/person in 2018/2019 and 5.45 tCO2e/person in 2022 (for a target of 6.0 tCO2/person). It should be 3.61 tCO2e/person in 2030.

The strategy (the long-term reduction trajectory and the team-based reduction objectives) is well received by the IGE laboratory staff, even if some staff are still reluctant to any form of reduction. To ease its implementation and check whether it is being kept, a bimonthly monitoring of the teams’ emissions and the mean personal CFP was set up. The IGE also proposes participation in awareness-raising tools (La Fresque du Climat, Ma Terre en 180'). Significant changes in travel habits have followed. For instance, out of the 30 members of the IGE who come to the EGU in Vienna each year, 90% came by plane and 10% by train (a 20-hour long journey) in 2018/2019, and this ratio was 25% by plane and 75% by train in 2022.

To achieve our objective, further actions need to be identified to reduce the "purchase" and "digital computing" emission posts. What will help is that the insulation of the buildings was initiated in 2022, and the cold rooms which emitted a very strong greenhouse gas (refrigerant gas R508b) were changed in 2022 for a model operating with CO2.

How to cite: Pellarin, T., Champollion, N., Gratiot, N., Teran-Escobar, C., Ruin, I., Panthou, G., Hingray, B., Delaygue, G., Jager, E., Lamothe, A., Piton, G., Evin, G., Blanchet, J., Philippon, N., Philip, A., Martinerie, P., and Picard, G.: Reducing the carbon footprint of a public research laboratory in Geosciences. Assessing a reduction strategy built with laboratory members after a 3-year experimentation, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13694, https://doi.org/10.5194/egusphere-egu23-13694, 2023.

EGU23-13910 | Orals | EOS4.1 | Highlight

Social production of ignorance – the role for geoscientists in addressing “undone science” 

Fiona Johnson, Philippa Higgins, Martin Andersen, Kirsty Howey, Matthew Kearnes, Stuart Khan, and Greg Leslie

In this presentation we discuss the role of geoscientists and engineers in advocating for improved civic science that can minimise the impacts of industrial and mining activities on the environment and downstream communities, with a particular focus on water-related impacts. We argue that, if not carefully designed, data collection, analyses and communication by geoscientists does not always contribute to the wider public good because the issues that communities care about are not addressed – so called “undone science”. A case study, focusing on the environmental impacts of the McArthur River mine (MRM) in a remote part of the Northern Territory, Australia, is used to highlight key issues that should inform civic science and lead to better outcomes for communities and the environment.

Despite thousands of pages of “data” about the MRM project and its impacts, we argue that this project is an example of the social production of ignorance – because the knowledge of the communities most impacted by the mine’s activities is not improved by the reporting and impact assessments associated with the project. Based on a temporal synthesis of independent monitoring reports of the McArthur River Mine which covered the period from 2007 to 2018, we identify three main lessons for improving civic science. Firstly, without adequate baseline monitoring prior to development, data collection during a project cannot satisfactorily assess impacts of a development. Baseline data is particularly important when seasonal and interannual variability is high. Baseline and ongoing monitoring programs should be co-designed with the community, so that what matters to the community is monitored (e.g. culturally important sites, contamination in animal species relevant to the community). Secondly, geoscientists and engineers need to partner with social scientists and local community organisations to ensure that communities are effectively informed about the impacts of development, focusing on the impacts that matter to communities, not just the impacts that are conveniently measured. Finally regulatory processes need to be improved to ensure that problems identified by geoscientists and engineers are addressed.

How to cite: Johnson, F., Higgins, P., Andersen, M., Howey, K., Kearnes, M., Khan, S., and Leslie, G.: Social production of ignorance – the role for geoscientists in addressing “undone science”, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13910, https://doi.org/10.5194/egusphere-egu23-13910, 2023.

EGU23-14085 | Posters virtual | EOS4.1

Carbon footprint and reduction initiatives in a French geosciences laboratory 

Laurent Jeanneau, Emilie Jardé, Anne-Laure Argentin, Annick Battais, Thomas Bernard, Alexandre Coche, Marion Fournereau, Frédérique Moreau, and Laure Guerit

The impact of our productivist societies on our environment is now clearly demonstrated. It is illustrated in particular by the alteration of biogeochemical flows, the erosion of biodiversity, the chemical pollution of environments, the anthropisation of soils, the alteration of the water cycle, the acidification of the oceans and climate change.

As higher education and research staff working at the interface between science and society, we are aware of the need for an environmental transition that can only be achieved by reducing our greenhouse gas emissions and our environmental impact. We do not believe that the content of our research justifies any form of exemption and are aware of the benefits of being exemplary. As a research lab, we are committed to participating in limiting the increase in the Earth's average temperature, ideally targeted at less than 1.5°C compared to the pre-industrial period. This objective requires achieving carbon neutrality by 2050.

From 2021 the Sustainable Development & Social Responsibility working group of the research laboratory “Géosciences Rennes” has been created (i) to determine the C footprint by using GES1.5 (Research Consortium labo1.5), (ii) to communicate and raising staff awareness of the climate emergency, (iii) to propose indicators for reducing the carbon footprint, (iv) to convey a message to the supervisory authorities to work on the various reduction items.

The calculated C footprint includes heating of buildings, electricity, purchase of goods and services, scientific missions and commutes. Between 2019 and 2021, the C footprint was 879, 520 and 708 T CO2eq, which corresponds to 5.8, 3.6 and 5.1 T CO2eq/person. The purchase of goods and services was the main item, representing 48 ± 8 % (mean ± SD) of the C footprint. Scientific missions represented 14 ± 9 % of the C footprint. Sanitary restrictions due to the covid pandemy induced a drastic decrease of the C footprint of scientific missions from 220 T CO2eq in 2019 to 43 T CO2eq in 2020.

Thanks to the GES1.5 toolkit, it is possible to identify the main emission items for a given laboratory and to design and quantify specific actions to collectively reduce the C footprint. These data were the corner stone of collaborative workshops to invent our low-carbon laboratory. This presentation will feature the data and the process of collective decision in “Géosciences Rennes” laboratory. These results highlight that achieving the European Union targets will require a rethinking of the way we do science. 

How to cite: Jeanneau, L., Jardé, E., Argentin, A.-L., Battais, A., Bernard, T., Coche, A., Fournereau, M., Moreau, F., and Guerit, L.: Carbon footprint and reduction initiatives in a French geosciences laboratory, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14085, https://doi.org/10.5194/egusphere-egu23-14085, 2023.

EGU23-14481 | Orals | EOS4.1

Project VECTOR – researching challenges to mining in Europe through a robust ethics structure. 

Chris Stockey, Sarah Gordon, Rose Clarke, and Emily Lewis and the VECTOR Partnership

VECTOR (Vectors to Accessible Critical Raw Material Resources in Sedimentary Basins) is an EU Horizon and UKRI co-funded research project assessing the social, technical, and environmental challenges to mining critical raw materials in Europe. Our commitment to geoethics is informed by the diverse partnership’s research expertise and our social science research. We will incorporate these learnings into all subsequent research and outreach programmes to promote good practice. Our dedicated ethics structure ensures that we put this commitment into practice. This approach to project ethics is a first for a Horizon Europe project.

Plans for decarbonisation presented in the EU Green Deal include achieving Net Zero by 2050 and reducing net greenhouse gas emissions by at least 55% by 2030 (compared to 1990 levels). Meeting the supply of renewable energy needed to achieve these goals requires a sharp increase in production, and a more responsible use, of critical raw materials. Recycling alone cannot meet the projected demand. Sourcing raw materials from inside the EU, where suitable environmental, social, and political regulations could be implemented, may be instrumental in securing an ethical provision of metals. However, mineral projects face complex social, environmental, and technical challenges in the EU. VECTOR will explore these challenges through social- and geoscience research, integrating the results of both research streams into easy-to-understand resources.

The VECTOR consortium is committed to ensuring the highest level of ethical standards during the project, with respect to both conduct and outputs. To put this commitment into practice, the VECTOR consortium has appointed an Ethics Advisor, responsible for advising the project on ethical matters and Chairing an Independent Ethics Committee, which will bring subject matter expertise to ethical deliberations. The Ethics Advisor and the Independent Ethics Committee sit within an ethics governance framework that interacts with, but is independent of, the Project governance framework. This ensures that ethical matters arising during the course of the Project are considered by expert, neutral third parties who are not otherwise directly invested in the Project, and that their advice is given due weight in Project decision making processes and practically implemented. This approach is a first for a Horizon Europe project, and one we hope will set the bar for strong ethical project management across the Horizon universe.

This will also be informed by our social science research to understand how stakeholders balance the ethical, social, economic, political, and environmental consequences of sourcing critical raw materials. The aim is to understand how levels of social acceptance influence attitudes, decisions and policy acceptance. Insights gained from this will inform good practice standards in our other research and be used to develop outreach tools targeting all stakeholder groups, informing their future decision making. These include policy makers and the much-overlooked public, as well as continued professional development pathways for geoscientists.

Taken together, our ethics structure and social science research provide a robust geoethics framework that will evolve with our new understandings and inform our work to investigate a socio-environmentally sustainable supply of raw materials.

How to cite: Stockey, C., Gordon, S., Clarke, R., and Lewis, E. and the VECTOR Partnership: Project VECTOR – researching challenges to mining in Europe through a robust ethics structure., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14481, https://doi.org/10.5194/egusphere-egu23-14481, 2023.

EGU23-14915 | ECS | Posters on site | EOS4.1

Is maximizing spatial resolution worth the computational cost? 

Yomna Eid and Edzer Pebesma

Link: https://docs.google.com/document/d/15788dfGPL5ehDaDsO7BsOKoGk3Bk7g2epKQ58HiYZVM/edit

The core of the modern data revolution is data centers: “the central nervous system of the 21st century,” [1] housing networking and storage equipment, and servers that enable services such as cloud computing. They consume increasing quantities of energy not only to run their operations, but also to cool down their servers. With advances in cloud computing and the growth of Internet services use, data centres are estimated to have the fastest growing carbon footprint from across the whole ICT sector.

Although the opportunities and risks of Big Data are often discussed in the geosciences, most of the literature and initiatives surprisingly neglect a crucial risk for sustainable development: the fact that the data revolution hampers sustainable development because of its environmental footprint. Therefore, the ability to quantify and project data centre energy use is a key energy and climate policy priority.

Remote sensing products present one of the highest storage-capacity demands, with imagery archives spanning petabytes. High- and very high-resolution remote sensing imagery has emerged as an important source of data for various geoscientific analysis, most of which are highly computationally taxing. With this trend in increasing spatial and temporal resolution, a crucial question remains - is the accuracy and overall quality of analysis results significantly impacted by substituting the standard high-resolution product with a less computationally-intensive, coarser-resolution one?

Emerging products such as the World Settlement Footprint [2] and Dynamic World [3] land use land cover maps, which are produced at very high temporal resolution (5 day) and spatial resolution (10 m). A generally accepted attitude is that developing products at higher resolutions is a legitimate scientific goal. However, the interest is often not which 10 m pixel changes land use and when exactly this happens, but rather how many pixels change land use over a larger area (a country, or basin) and over a larger time period (e.g. by year over a decade). For a few high resolution products we evaluate and report how such aggregated target quantities computed from lower spatial and temporal resolution data change the quality (accuracy) of the final product, and which resolutions still seem acceptable.

[1] Lucivero, F. Big Data, Big Waste? A Reflection on the Environmental Sustainability of Big Data Initiatives. Sci Eng Ethics 26, 1009–1030 (2020). https://doi.org/10.1007/s11948-019-00171-7

[2] Marconcini, M., Metz-Marconcini, A., Üreyen, S. et al. Outlining where humans live, the World Settlement Footprint 2015. Sci Data 7, 242 (2020). https://doi.org/10.1038/s41597-020-00580-5

[3] Brown, C.F., Brumby, S.P., Guzder-Williams, B. et al. Dynamic World, Near real-time global 10 m land use land cover mapping. Sci Data 9, 251 (2022). https://doi.org/10.1038/s41597-022-01307-4

How to cite: Eid, Y. and Pebesma, E.: Is maximizing spatial resolution worth the computational cost?, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14915, https://doi.org/10.5194/egusphere-egu23-14915, 2023.

EGU23-15941 | Orals | EOS4.1 | Highlight

The UK Climate Resilience Programme (2019-2023) 

Suraje Dessai, Kate Lonsdale, Jason Lowe, Rachel Harcourt, and Peter Walton

Even with the successful implementation of the Paris agreement, a certain amount of climate change is now unavoidable over the next few decades and high warming levels by the end of the century cannot be ruled out. Therefore, urgent action is needed to build resilience and accelerate adaptation to climate variability and change. Informing the extensive range of actions needed to manage climate risks, reduce damage without exacerbating existing inequalities, and realise emerging opportunities, is a critical scientific and societal challenge. The UK has been at the forefront of climate adaptation policy with the Climate Change Act 2008 requiring the UK Government to conduct a five-yearly Climate Change Risk Assessment (CCRA) and National Adaptation Programme. Another important recent driver amongst UK organisations has been compliance with the Task Force on Climate-Related Financial Disclosures. The UK Climate Resilience (UKCR) Programme emerged as a response to these policy and societal needs. It aims to enhance the UK’s resilience to climate variability and change through frontier interdisciplinary research and innovation on climate risk, adaptation and services, working with stakeholders and end-users to ensure the research is useful and usable.

The UK Climate Resilience Programme, led by UK Research and Innovation and the UK Met Office and running from 2019 to 2023, has funded over 50 projects worth £19 million. It is part of the Strategic Priorities Fund initiative which provides research funding to develop strategically important research for the national government. Topics central to the programme’s research agenda have included improved characterisation and quantification of climate risks, enhanced understanding of the management of climate risks, and the development and delivery of climate services. Amongst its achievements, the programme has: developed a set of future UK socio-economic scenarios to be used alongside climate scenarios, delivered a step change in climate change risk assessment capability, and produced a roadmap for the development and implementation of UK climate services. It has funded arts and community based projects and pioneered an embedded researchers scheme in which the researcher collaborates with a host organisation to address their real world needs. The programme has also developed a more coherent community of climate resilience researchers and practitioners in the UK.

In this talk we will provide an overview of the programme, focusing on the nexus between UKCR–funded research, and UK policy and practice. For example, we will consider how the national CCRA process shaped the programme’s research agenda while at the same time the availability of research sets the parameters of risk assessments. We will also provide examples of co-production undertaken by researchers and practitioners and comment on what can be achieved in terms of societal resilience when there is collaboration on shared objectives. This programme is unique in dedicating significant time, funding and other resources to researching national resilience while working in close partnership with the national government. We anticipate that our learnings from this process will be of interest to other researchers, as well as policy makers and practitioners who work with researchers on climate resilience issues.

How to cite: Dessai, S., Lonsdale, K., Lowe, J., Harcourt, R., and Walton, P.: The UK Climate Resilience Programme (2019-2023), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15941, https://doi.org/10.5194/egusphere-egu23-15941, 2023.

EGU23-15959 | Posters on site | EOS4.1 | Highlight

Changing the narrative: the hidden histories of British colonial mineral exploitation in Africa 

Dr Munira Raji, Dr Rebecca Williams, Dr Anya Lawrence, Dr Nicholas Evans, Professor Trevor Burnard, Dr M. Satish Kumar, Keely Mills, Steven Rogers, Catharine Souch, George Jameson, Jacqui Houghton, and Natasha Dowey

At the height of colonial Europe, during the late 18th century, many of the principles, theories, laws and practices that shape the (Western) academic discipline of Earth Science were established. However, during this imperial production of knowledge, there was little reference to or acknowledgement of any pre-existing geological knowledge. The legacy of colonialism is perpetuated through many modern Earth Science practices and education activities, and the influence of this legacy adds to the perception of Earth Science as a white, western-dominated subject and the erasure and dismissal of other geological knowledge. This project explores the unacknowledged local geological knowledge and labour upon which the foundational institutions of Earth Science are built and how this legacy creates modern-day exploitation, unethical behaviour and inequity in our discipline. 

 

We uncover some of the hidden histories of colonial mineral exploitation, including the role of British geologists and geological institutions in expanding colonial rule in Africa and how local geological knowledge and local guides underpinned the activities of the colonial geological surveys. British mineral exploitation in Africa started in the seventeenth century with a series of expeditions by pioneer British geologists and prospectors into South Africa's interior to make preliminary observations and geological surveys for minerals. More expeditions to other parts of Africa followed in the eighteenth century. During the late eighteenth century, many of the principles, theories, laws and practices that shaped the academic discipline of Earth Science were established in parallel to colonial expansion. The British Empire sustained a programme of exploratory geological surveys and activities directly linked with mapping the geological features to locate and discover economic mineral resources to fuel the British economy and industrialise the British Empire. Exploitable deposits of coal, copper, iron and limestone's essential smelting flux were vital for the long-term development of steamship lines, railways, and industry. 

 

At the end of the First World War, the British government promoted and intensified geological surveys in several British Empire territories – Uganda, Sierra Leone and Nigeria in 1918, Tanzania in 1925 and Kenya in 1933. Some pioneer British geologists were heralded for their pioneering work and credited with the discovery of economically significant minerals in Africa. Our archival investigation reveals many of these mineral resources were already used and mined locally and that local knowledge underpinned these resource 'discoveries' and local people were used as field assistants, guides, carriers, labourers, and camp guides. These pioneer geologists relied on the colonial structure to obtain information from natives central to fieldwork, mineral investigation, and discoveries. Still, history has omitted the contributions of the natives involved in these mineral discoveries and the acknowledgement of any local geological knowledge. Perhaps it is time to change the narrative from one of discovery to one of exploitation. As a discipline, by reckoning with the colonial legacy of our past, we can seek to normalise working with local knowledge and knowledge outside the boundaries of (western) Earth Science, leading to ethical,  equitable, interdisciplinary work, better preparing the discipline for current global challenges.

How to cite: Raji, D. M., Williams, D. R., Lawrence, D. A., Evans, D. N., Burnard, P. T., Kumar, D. M. S., Mills, K., Rogers, S., Souch, C., Jameson, G., Houghton, J., and Dowey, N.: Changing the narrative: the hidden histories of British colonial mineral exploitation in Africa, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15959, https://doi.org/10.5194/egusphere-egu23-15959, 2023.

EGU23-16302 | Orals | EOS4.1 | Highlight

An Ethical Framework for Climate Intervention Research and Potential Scaling 

Billy Williams, Brooks Hanson, Raj Pandya, Janice LaChance, and Mark Shimamoto

Climate change is a global threat. As such, scientific and technology organizations and funders are increasingly devoting attention and resources to climate intervention research and, in some cases, already pursuing large-scale testing. Climate intervention measures include carbon dioxide removal and solar radiation management. The U.S. National Academy of Sciences and many other authoritative bodies have called for "a code of conduct" and governance structure to guide the research, potential scaling and possible deployment of these intervention measures.  This presentation will discuss a global initiative facilitated by AGU to help establish and gain support for an ethical framework to help guide such efforts, and to include various practical, ethical and governance considerations of potential climate intervention technologies to be considered before deciding potential scaled deployment of such measures – including climate justice considerations and representation.  Preliminary ethical framework modules and global engagement processes currently underway will be discussed.

How to cite: Williams, B., Hanson, B., Pandya, R., LaChance, J., and Shimamoto, M.: An Ethical Framework for Climate Intervention Research and Potential Scaling, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16302, https://doi.org/10.5194/egusphere-egu23-16302, 2023.

EGU23-16734 | Orals | EOS4.1

Impact of the COVID19 crisis on changes in business travel and the associated carbon footprint. Case study of a French scientific research institute. 

Christophe Peugeot, Grolleau Dany, Play Caroline, Sultan Benjamin, Hernandez Valeria, Janicot Serge, and Tramblay Yves

The French National Research Institute for Sustainable Development (IRD) is a multidisciplinary academic organisation working in partnership with countries in the Mediterranean and intertropical zone. Through sustainability science, IRD is committed to achieving the Sustainable Development Goals. Because of its missions, the IRD has a particular footprint linked to the activities of its agents (2100 employees in 2020) and partners, who travel between France and the rest of the world.

The COVID19 health crisis has forced changes in work habits. This study aims to analyze the impact of these changes on carbon emissions. All business trips of IRD employees and partners in the period 2017-2022 were collected in an anonymized database (aboout 67,000 entries), which describes trips, mode of transportation, reasons for travel, and traveler status.

The annual number of trips dropped sharply during the health crisis, from an average of 14,000/year in 2017-2019 to less than 6,000 in 2022 (-60%). Associated carbon emissions dropped by 70%. Starting in 2021, the number of trips increased to about 90% of pre-covid levels in 2022. However, while the share of air travel in total travel has decreased slightly in 2022 compared to 2017-2019, the share of car travel has increased sharply over the past three years, at the expense of train travel, which remains less used than before COVID. On a finer scale, the share of each mode of transport (and therefore the associated footprint) differs markedly according to the regions in which the research teams work, depending on the type of activity and the modes of transport available (e.g. rail travel mainly in Europe, field campaigns mainly by car).

The analysis highlights that the few trips authorized in 2020 and 2021 were primarily for overseas field activities or mobilities, to and from France. These activities, which cannot be replaced by videoconferencing and which constitute the core of IRD's activity, have been prioritized. The widespread use of videoconferencing has reduced the need for travel, especially for meetings and conferences. This is likely accompanied by an increase in virtual meetings, the associated footprint of which is not assessed here.

Traveling less, using videoconferencing when possible, or pooling several objectives for a single trip are trends that seem to emerge from our analysis. It is interesting to note that they are consistent with the actions proposed by research teams engaged in footprint reduction strategies, as highlighted for example by the serious game "Ma Terre en 180'" or the national survey of the Labo1point5 group.

Our analysis, with only one year without travel restrictions (2022), must be consolidated over a longer period (at least 3 years) to assess the sustainability of practice changes and their impact on IRD's carbon footprint. These results will serve as guidelines to define the necessary actions to reduce the environmental footprint of IRD research activities.

How to cite: Peugeot, C., Dany, G., Caroline, P., Benjamin, S., Valeria, H., Serge, J., and Yves, T.: Impact of the COVID19 crisis on changes in business travel and the associated carbon footprint. Case study of a French scientific research institute., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16734, https://doi.org/10.5194/egusphere-egu23-16734, 2023.

We desire to know out of different motivations. According to Aristotle, scientists can feel happy or eudaimon when they fulfill the final cause of humans, reasoning, by providing knowledge. Freud argued that infants start to learn in order to distinguish between conditions that cause them pain or pleasure. We want to increase chances of achieving desired outcomes and avoiding undesired outcomes of our decisions by understanding causalities between events and predicting future events. In Geoscientific contexts, we may want to understand nature in order to satisfy different desires such as physical and psychological comforts, ethical dignity and continuation of existence, which are inseparable from but also conflict often against each other. We seek optimal decisions by means of the Geoscientific knowledge amidst the conflicting desires and natural conditions that hamper the desires.

All formations in the universe and all our perceptions are impermanent. Buddhism views that the course of life in which one is born, ages, gets ill and dies is suffering, if one clings to satisfactions, existence or non-existence as they are impermanent. A human being is seen in Buddhism as an ever-changing flux comprised of body (rupa in Pali language), senses (vedana), perceptions (sanna), volitions (sankhara) and consciousness (vinnana), or the five aggregates (khandha). Lasting peacefulness can be experienced when one understands the impermanence of its five aggregates, or selflessness (sunnata), which is a goal of Buddhist practices.

From this Buddhist perspective, satisfactions of material needs provided by Geoscience do not last permanently. Geoscience may help humans satisfy their basic needs, but the standards of basic needs seem to be ever-growing, influenced often by materialism which overlooks spiritual sources of happiness and technocentric hopes for sustainability in the future. According to Buddhism, our experiences and actions (kamma) condition our perceptions, volitions and habits, and reifying them as constant or substantial leads us to assume that certain desires ‘ought’ to be met as basic living standards. However, such standards are subjective judgements that cannot be justified by factual propositions in ‘is’ forms.

It can be satisfying for scientists to perform their professional tasks of providing knowledge required for fulfilling the human needs. However, epistemic and aleatory uncertainties in Geoscience can frustrate their desire to know. Geoscientists may suffer from the frustration, if they cling to their tasks and desires, failing to see satisfactions as impermanent and uncertainties as natural processes.

It is important to note that Buddhism does not compel dogmatically ascetic life styles or nihilistic worldviews but suggests ways to cease suffering. The Threefold Training (ethics, mindfulness and wisdom), the practice methods of Buddhism, can be applied in pursuing Geoscience as opportunities to experience lasting peacefulness. Scientists can create peaceful conditions by helping others with their knowledge, and let go of their reification and desires through mindfulness and the Buddhist ontology. Studying human desires and providing honest information about uncertainties and physical boundaries of satisfying the desires would be also parts of the practice.

How to cite: Jung, H.: Buddhist thoughts on frustration of the desire the know in Geoscience, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17116, https://doi.org/10.5194/egusphere-egu23-17116, 2023.

EGU23-17583 | Orals | EOS4.1

Inform international institutions for interdisciplinary development strategies linking nutrition enhancement and climate change adaptation 

Giulia Galluccio, Chiara Trozzo, Monia Santini, Marta Antonelli, and Océane Espin

Climate change and malnutrition, that includes undernutrition as well as micronutrient deficiency and overweight, are among the greatest issues in the 21st century. Acting in synergy, each of these dynamics aggravates the effects of the other, creating complex and compounding impacts that increase particularly the vulnerability of the poorest people. This so-called climate and nutrition nexus can be broadly described as the fact that climate change poses a serious threat to global nutrition security, while current food systems are contributing significantly to this warming dynamic and malnutrition is reducing people’s ability to cope with the induced changes. Therefore, climate information and science are crucial to inform both international funding institutions (especially their investment portfolios) and local decision-makers in the design and selection of comprehensive, effective and innovative strategies and actions to adapt and cope with climate change and therefore advance sustainable development at all scales.

Regarding this topic, we carried out a consultancy project funded by the ASAP II programme of the International Fund for Agricultural Development (IFAD) to inform its investment portfolio on the design and implementation of interdisciplinary development strategies linking nutrition enhancement and climate change adaptation. We reviewed and analysed 7 selected IFAD ‘climate related and nutrition-sensitive projects’ in Latin America and the Caribbean. The identification of best practices and lessons learned to be cultivated, scaled-up and even mainstreamed in future projects will encourage the sustainable transformation of the food systems, increase the climate resilience of the population and fight inequalities in the region.

Our work was articulated in three stages. Firstly, a wide literature review of scientific articles and other relevant documents published to date on the climate and nutrition nexus has been carried out, as well as a review of all related project documentation. This primary data collection and analysis has been complemented by conducting semi-structured interviews with key stakeholders from the projects. As part of this study, a two-day peer-to-peer sharing event was organised to assess the know-how accumulated by the participants and aimed to create an environment conducive to the exchange of knowledge and experiences, as well as to present and validate preliminary research results.

Our results are compiled in a practical guidebook that focuses on 9 main themes. The analysis allowed us to identify adaptation knowledge and solutions coming directly from the field and tested during the projects. The added value of considering the climate and nutrition nexus is to point out the numerous co-benefits of actions and practices which can both contribute to climate change mitigation and adaptation, and to the promotion of sustainable agricultural systems and healthy diets. The majority of the solutions identified concern: the consideration of the most vulnerable communities and populations, and in particular the empowerment of women, youth and indigenous people; governance and organisation from the global scale with South-South cooperation to the household level; and finally, the use of information from both traditional knowledge and more technical studies, as well as the implementation of climate-smart and nutrition-sensitive agriculture practices.

How to cite: Galluccio, G., Trozzo, C., Santini, M., Antonelli, M., and Espin, O.: Inform international institutions for interdisciplinary development strategies linking nutrition enhancement and climate change adaptation, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17583, https://doi.org/10.5194/egusphere-egu23-17583, 2023.

Geomorphological mapping is one of the primary research methods used to collect data on glacial landforms and reconstruct glaciological processes. The most common approach is a combination of field-based and remote mapping using data obtained from various sensors. However, one of the crucial methodical problems is collecting remote sensing data in the appropriate spatial resolution for the analyzed landform, which directly affects the data collection time and costs. This study aims to find the optimal resolution of digital elevation models (DEMs) to map subtle glacial landforms: kame terraces, eskers, flutes, and push moraine. Such landforms contain valuable information about the glacial process–form relationships, however, are often too subtle to be recognized on satellite data, and therefore more detailed data (e.g., UAV-based) are required. By “optimal”, we mean the resolution high enough to enable recognition of the landforms mentioned above, and at the same time, as low as possible to minimize the time spent on data collection during the fieldwork.

To find out the optimal resolution, we used detailed (0.02 – 0.04 m ground sampling distance [GSD]) DEMs of the glacier forelands in Iceland (Kvíárjökull, Fjallsjökull and Svinafellsjökull), created based high-resolution images from an unmanned aerial vehicle (UAV). The DEMs were resampled to 0.05, 0.10, 0.15, 0.20, 0.30, 0.40, 0.50, 1.00 and 2.00 m GSD and selected glacial landforms were mapped independently by two operators and cross-checked. The results indicate that 2.0 m resolution is insufficient to properly recognize landforms such as pushed moraines or flutes; however, it can be sufficient to detect kame terraces and major glacifluvial channels. For general mapping of locations of forms such as annual pushed moraines or fluting, the 0.5 m resolution is required. However, to obtain geomorphometric characteristics of the landforms (e.g., height, width, volume) resolution between 0.1 and 0.2 m is necessary. Finer resolution (better than 0.05 m GSD) does not increase the ability to detect landforms or better characterize their geometric properties; however, in some cases might be useful to obtain information about clast characteristics. The experiment proved that decimeter-scale spatial resolution is sufficient for mapping of some geomorphological forms (annual pushed moraines, flutes), which allows for planning UAV missions at a higher elevation above the ground and, therefore, minmizing the duration of field surveys. Moreover, some of the more prominent landforms (e.g., kame terraces, larger moraines) can be successfully detected from aerial or satellite-based DEMs (e.g. freely available ArcticDEM) with a resolution of 2.00 m, the use of which reduces the costs of field research to a minimum.

This research was funded by the National Science Centre, Poland, Grant Number 2019/35/B/ST10/03928.

How to cite: Śledź, S. and Ewertowski, M.: Optimal resolution of UAV-based digital elevation models (DEMs) for mapping of selected subtle glacial landforms, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-151, https://doi.org/10.5194/egusphere-egu23-151, 2023.

EGU23-3292 | Posters on site | GI6.1

CO2 concentration and stable isotope surveys in the ambient air of populated areas of La Palma (Canary Islands) by means of mobile Delta Ray measurements using an electrical car 

Nemesio M. Pérez, María Asensio-Ramos, José Barrancos, Eleazar Padrón, Gladys V. Melián, Fátima Rodríguez, Germán D. Padilla, Violeta T. Albertos, Pedro A. Hernández, Antonio J. Álvarez Díaz, Héctor de los Ríos Díaz, David Afonso Falcón, and Juan Cutillas

Anomalous CO2 degassing of volcanic origin was observed by the end of November 2021 in the neighborhoods of La Bombilla and Puerto Naos, located in the western flank of La Palma, about 5 km distance southwestern of the 2021 Tajogaite eruption vents (Hernández et al., 2021). In this study zone, continuous monitoring of CO2 concentration in the outdoors ambient air at 200 cm from the surface has reached a daily average of maximum and mean values about 28,000 and 10,000 ppm, respectively. We started recently to perform CO2 concentration and stable isotope surveys in the outdoors ambient air of Puerto Naos at 140 cm from the surface by means of a Delta Ray analyzer installed in an electrical car which was driving through the streets of Puerto Naos. This instrument is a high performance, mid-infrared laser-based, isotope ratio infrared spectrometer (IRIS) which offers the possibility of performing simultaneous determination of δ13C and δ18O in CO2 at ambient concentrations with a precision as low as 0.05‰. One major advantage of IRIS techniques with respect to more traditional ones (e.g., isotopic ratio mass spectrometry -IRMS-) is the possibility to perform (semi)continuous measurements at high temporal resolution. Since October 2022, seven surveys have been performed at Puerto Naos making up a total of about 600 measurements. The observed CO2 concentrations and the δ13C-CO2 values in the outdoors ambient air ranged from 420 to 3,500 ppm and from -9.0 to -3.2 ‰ vs. VPDB, respectively. Survey data analysis showed a good spatial correlation between relatively high CO2 concentrations with δ13C-CO2 values less 13C-depleted (i.e., volcanic CO2). These observations highlight that stable isotope surveys allow to evaluate the impact of volcanic degassing on the air CO2 concentration and provide valuable results to identify the volcanic CO2 gas hazard zones.

Hernández, P. A., Padrón, E., Melián, G. V., Pérez, N. M., Padilla, G., Asensio-Ramos, M., Di Nardo, D., Barrancos, J., Pacheco, J. M., and Smit, M.: Gas hazard assessment at Puerto Naos and La Bombilla inhabited areas, Cumbre Vieja volcano, La Palma, Canary Islands, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7705, https://doi.org/10.5194/egusphere-egu22-7705, 2022.

How to cite: Pérez, N. M., Asensio-Ramos, M., Barrancos, J., Padrón, E., Melián, G. V., Rodríguez, F., Padilla, G. D., Albertos, V. T., Hernández, P. A., Álvarez Díaz, A. J., de los Ríos Díaz, H., Afonso Falcón, D., and Cutillas, J.: CO2 concentration and stable isotope surveys in the ambient air of populated areas of La Palma (Canary Islands) by means of mobile Delta Ray measurements using an electrical car, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3292, https://doi.org/10.5194/egusphere-egu23-3292, 2023.

EGU23-3620 | ECS | Posters on site | GI6.1

SO2 emissions during the post-eruptive phase of the Tajogaite eruption (La Palma, Canary Islands) by means of ground-based miniDOAS measurements in transverse mode using a car and UAV 

Oscar Rodríguez, José Barrancos, Juan Cutillas, Victor Ortega, Pedro A. Hernández, Iván Cabrera, and Nemesio M. Pérez

Throughout the 85 days that lasted the Tajogaite eruption at Cumbre Vieja volcano (La Palma, Canary Islands, Spain), observations of SO2 emissions were made using ground-based instruments, in transverse mode, static scanners and on-board drones, as well as by numerous satellite instruments. The initial estimates of the total SO2 emission from the eruption were 2.4 Mt from TROPOMI and 1.2 Mt from the traverse data. These measurements formed part of the official monitoring effort, providing insights into the eruption’s evolution and informing the civil defence response throughout the eruption (Hayer C. et al., 2022; Albertos V. T. et al., 2022). Once the Tajogaite eruption was over, we continued performing a SO2 monitoring release to the atmosphere by the Tajogaite volcanic vent since the low ambient concentrations of SO2 make it an ideal volcanic gas monitoring candidate even during the post-eruptive phase. SO2 measurements had been carried out a using a car-mounted and UAV-mounted ground-based miniDOAS measurements throughout this post-eruptive phase. About 80 measurements of SO2 emission rates were performed from December 15, 2021 to December 17, 2022. The standard deviation of the estimated values obtained daily was ~ 20%. The range of estimated SO2 emission values has been from 670 to 17 tons per day, observing a clear decreasing trend of SO2 emissions during the post-eruptive phase. During the first month of the post-eruptive phase, it was observed that the average value of the estimated SO2 emission was about 219 tons/day, while it dropped to 107 tons/day during the second and third month after the end of the Tajogaite eruption. This average value continued decreasing during the fourth month of the post-eruptive phase, about 67 tons/day, and recently measurements provide an average SO2 emission value of 13 tons/day. These relatively low observed SO2 emissions during the post eruptive of the Tajogaite eruption phase seems to be clearly related to shallow magma cooling processes within the Tajogaite volcanic edificie.

Hayer, C., Barrancos, J., Burton, M., Rodríguez, F., Esse, B., Hernández, P., Melián, G., Padrón, E., Asensio-Ramos, M., and Pérez, N.: From up above to down below: Comparison of satellite- and ground-based observations of SO2 emissions from the 2021 eruption of Cumbre Vieja, La Palma, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12201, https://doi.org/10.5194/egusphere-egu22-12201, 2022.

Albertos, V. T., Recio, G., Alonso, M., Amonte, C., Rodríguez, F., Rodríguez, C., Pitti, L., Leal, V., Cervigón, G., González, J., Przeor, M., Santana-León, J. M., Barrancos, J., Hernández, P. A., Padilla, G. D., Melián, G. V., Padrón, E., Asensio-Ramos, M., and Pérez, N. M.: Sulphur dioxide (SO2) emissions by means of miniDOAS measurements during the 2021 eruption of Cumbre Vieja volcano, La Palma, Canary Islands, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5603, https://doi.org/10.5194/egusphere-egu22-5603, 2022.

How to cite: Rodríguez, O., Barrancos, J., Cutillas, J., Ortega, V., Hernández, P. A., Cabrera, I., and Pérez, N. M.: SO2 emissions during the post-eruptive phase of the Tajogaite eruption (La Palma, Canary Islands) by means of ground-based miniDOAS measurements in transverse mode using a car and UAV, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3620, https://doi.org/10.5194/egusphere-egu23-3620, 2023.

EGU23-3819 | Posters virtual | GI6.1

Using tunable diode laser (TDL) system in urban environments to measure anomalous CO2 concentrations: the case of Puerto Naos, La Palma, Canary Islands 

José Barrancos, Germán D. Padilla, Gladys V. Melián, Fátima Rodríguez, María Asensio-Ramos, Eleazar Padrón, Pedro A. Hernández, Jon Vilches Sarasate, and Nemesio M. Pérez

Carbon dioxide (CO2) is a colourless and odourless gas. It is non-flammable, chemically non-reactive and 1.5 times as heavy as air; therefore, may accumulate at low elevations. CO2 is a toxic gas at high concentration, as well as an asphyxiant gas (due to reduction in oxygen). Irritation of the eyes, nose and throat occurs only at high concentrations. Since the Tajogaite eruption ended on December 13, 2021, high concentrations of CO2 up to 20% (200.000 ppmv) have been observed inside of buildings of the neighborhoods of La Bombilla and Puerto Naos (La Palma, Canary Islands), which are located about 5 km distance from the Tajogaite eruption vent. Anomalous concentrations of CO2 are manily detected in the ground-floor and basement of the buildings in Puerto Naos, and the distribution of relatively high CO2 concentrations  is not homogeneous or uniform throughout the Puerto Naos area (Hernández P.A. et al, 2022).

The purpose of this study was to use the Tunable Laser Diode (TDL) absorption spectroscopy method to monitor the indoor CO2 concentration of the ground-floor of one of the buildings of Puerto Naos. A CO2-TDL was installed on 9 January 2022 and continues measuring the CO2 concentration along an optical path of about 6 meters. During the period January-March 2022, daily averages of CO2 concentrations from fifteen-minute data ranged from 5000 to 25000 ppmv reaching values up to 40000 ppmv (4%). Over time, a clear decreasing trend of the indoor CO2 concentration has been observed at this observation site and the daily CO2 averages from fifteen-minute data during the last 3 months (October-December 2022) ranged from 1000 to 2500 ppmv. This clear decreasing trend over time has not been observed at other observation sites where the concentration of CO2 inside buildings is being monitored. This observation indicates the complexity of the problem and the need to install a dense network of sensors to monitor CO2 for civil protection purposes.

 

Hernández, P. A., Padrón, E., Melián, G. V., Pérez, N. M., Padilla, G., Asensio-Ramos, M., Di Nardo, D., Barrancos, J., Pacheco, J. M., and Smit, M.: Gas hazard assessment at Puerto Naos and La Bombilla inhabited areas, Cumbre Vieja volcano, La Palma, Canary Islands, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7705, https://doi.org/10.5194/egusphere-egu22-7705, 2022.

How to cite: Barrancos, J., Padilla, G. D., Melián, G. V., Rodríguez, F., Asensio-Ramos, M., Padrón, E., Hernández, P. A., Vilches Sarasate, J., and Pérez, N. M.: Using tunable diode laser (TDL) system in urban environments to measure anomalous CO2 concentrations: the case of Puerto Naos, La Palma, Canary Islands, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3819, https://doi.org/10.5194/egusphere-egu23-3819, 2023.

EGU23-3834 | Posters on site | GI6.1

Modeling outdoor dispersion of CO2 at Puerto Naos (La Palma, Canary Islands) 

Luca D Auria, Alba Santos, Pedro A. Hernández, Gladys V. Melián, Antonio J. Álvarez Díaz, María Asensio-Ramos, Alexis M. González Pérez, and Nemesio M. Pérez

The 2021 Tajogaite eruption in Cumbre Vieja volcano (La Palma, Canary Islands), which started on Sep. 19, 2021, and lasted 85 days, caused extensive damages because of the lava flows and ash fall. However, since the middle of Nov. 2021, some areas located about 5 km SW of the eruptive center started to be affected by intense diffuse CO2 emission. Among them are the urban centers of La Bombilla and Puerto Naos (Hernández et al., 2022). These emissions prevented the population of these two centers from returning to their houses because of high  concentrations of CO2 in indoor and outdoor environments.

In this work, we model the CO2 dispersion process in Puerto Naos to obtain hazard maps with the maximum CO2 concentrations which can be reached in the town in the outdoor environment. To achieve these results, we combined field observations with numerical modelling. Field surveys were realized in low wind conditions, measuring the CO2 concentration with portable sensors  at 15 and 150 cm from the ground at measurement points spaced approximately 10 m from each other along the streets of Puerto Naos.

We realized numerical modelling using the software TWODEE-2, a code for modeling the dispersion of heavy gases based on the solution of shallow water equations (Folch et al., 2009). For this purpose, we used a detailed digital topographic model, including the edifices of Puerto Naos. Using a trial-and-error approach, we determined the gas emission rates from a set of discrete source points in no-wind conditions. Subsequently, we repeated the numerical modelling, keeping the same sources and simulating all the realistic wind conditions in terms of direction and intensity. For each simulation, we determined the maximum CO2 concentration at different elevations from the ground. This allowed obtaining a hazard map with the maximum CO2 outdoor concentrations for each part of the town

The main results highlight that the outdoor environment is affected by a dense layer of CO2, whose flow is strongly conditioned by the urban infrastructures. Furthermore, we evidenced how even light winds can change the gas concentration pattern radically in a few minutes, evidencing the possibility of sudden changes in the CO2 concentration outdoors with no warning.

Folch A., Costa A., Hankin R.K.S., 2009. TWODEE-2: A shallow layer model for dense gas dispersion on complex topography, Comput. Geosci., doi:10.1016/j.cageo.2007.12.017

Hernández, P. A., Padrón, E., Melián, G. V., Pérez, N. M., Padilla, G., Asensio-Ramos, M., Di Nardo, D., Barrancos, J., Pacheco, J. M., and Smit, M.: Gas hazard assessment at Puerto Naos and La Bombilla inhabited areas, Cumbre Vieja volcano, La Palma, Canary Islands, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7705, https://doi.org/10.5194/egusphere-egu22-7705, 2022.

How to cite: D Auria, L., Santos, A., Hernández, P. A., Melián, G. V., Álvarez Díaz, A. J., Asensio-Ramos, M., González Pérez, A. M., and Pérez, N. M.: Modeling outdoor dispersion of CO2 at Puerto Naos (La Palma, Canary Islands), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3834, https://doi.org/10.5194/egusphere-egu23-3834, 2023.

EGU23-5223 | Orals | GI6.1

Event-oriented observation across scales and environmental systems: MOSES started operation. 

Ute Weber and Claudia Schuetze and the MOSES-Team

The novel observing system „Modular Observation Solutions for Earth Systems (MOSES)“, is an initiative of the Helmholtz Association of German Research Centers that aims at investigating the interactions of short-term events and long-term trends across environmental systems. MOSES is a mobile and modular infrastructure and its component measuring systems are managed by the participating research centers. By quantifying energy, water, nutrient and greenhouse gas states and fluxes during events such as heat waves, droughts, heavy precipitation, floods, rapid thaw of permafrost or of ocean eddies, and subsequently along the related event chains, the system delivers data to examine potential long-term impacts of these events and to gain a better understanding of extreme events that are expected to increase in frequency and intensity in a changing climate. In order to obtain comprehensive data sets, a cross-system approach is followed, covering the atmosphere, land surface and hydrosphere. These event-related data sets complement long-term and/or large scale data sets of established national and international monitoring programs and satellite data such as TERENO, ICOS, eLTER, SENTINEL, etc. After a 5-year setup period, MOSES was successfully put into operation in 2022 (Weber et al., 2022, https://doi.org/10.1175/BAMS-D-20-0158.1).

While long-term trends are typically assessed with stationary observation networks and platforms specifically designed for long-term monitoring, proven event-oriented observation systems and strategies are still missing. Event-oriented observation campaigns require a combination of a) measuring systems that can be rapidly deployed at “hot spots” and in “hot moments”, b) mobile equipment to monitor spatial dynamics in high-resolution, c) in situ measuring systems to record temporal dynamics in high-resolution, and d) interoperable measuring systems to monitor the interactions between atmosphere, land surface and hydrosphere. We will present the observation system and the observing strategy on examples from two past test campaigns: 1) The “Swabian MOSES campaign” of 2021 that captured the formation and evolution of supercells, hail and heavy precipitation and the resulting local flash floods (Kunz et al., 2022, https://doi.org/10.3389/feart.2022.999593). 2) The MOSES campaign of 2019 that captured the historical low flow situation along the Elbe River and into the German Bight (e.g., Kamjunke et al., 2021, https://doi.org/10.1002/lno.11778). As an outlook, upcoming national and international campaigns and potential future deployments will be presented.

How to cite: Weber, U. and Schuetze, C. and the MOSES-Team: Event-oriented observation across scales and environmental systems: MOSES started operation., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5223, https://doi.org/10.5194/egusphere-egu23-5223, 2023.

EGU23-5684 | ECS | Posters on site | GI6.1

Random Forest Classification of Proterozoic and Paleozoic rock types of Tsagaan-uul area, Mongolia 

Munkhsuren Badrakh, Narantsetseg Tserendash, Erdenejargal Choindonjamts, and Gáspár Albert

The Tsagaan-uul area of the Khatanbulag ancient massif in the Central Asian Orogenic Belt is located in the southern part of Mongolia, which belongs to the Gobi Desert. It has a low vegetation cover, and because of this, remotely sensed data can be used without difficulty for geological investigations. Factors such as sparse population and underdeveloped infrastructure in the region further create a need for combining traditional geological mapping with remote sensing technologies. In existing geology maps of the area, the formations are lithologically very diverse and their boundaries were mapped variously, so a need for a more precise lithology-based map arouse.

This study investigated combinations of fieldwork, multispectral data, and petrography for the rock type classification. A random forest classification method using multispectral Sentinel-2A data was employed in order to distinguish different rocks within Proterozoic Khulstai (NP1hl) metamorphic complex, which is dominated by gneiss, andesite, sandstone, limestone, amphibolite, as well as the Silurian terrigenous-carbonate Khukh morit (S1hm) formation, Tsagaan-uul area. Based on the ground samples collected from field surveys, ten kinds of rock units plus Quaternary sediments were chosen as training areas. In addition, morphometric parameters derived from SRTM data and band ratios used for iron-bearing minerals from Sentinel 2 bands are selected as variables in the accuracy of classification. The result showed that gneisses were recognized with the highest accuracy in the Khulstai complex, and limestones and Quaternary sediments were also well predicted. Moreover, the tectonic pattern was also well recognized from the results and compared to the existing maps provided a more detailed geological image of the area. This study emphasized the need for samples as baseline data to improve the machine learning methods, and the method provides an appropriate basis for fieldwork.

 

How to cite: Badrakh, M., Tserendash, N., Choindonjamts, E., and Albert, G.: Random Forest Classification of Proterozoic and Paleozoic rock types of Tsagaan-uul area, Mongolia, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5684, https://doi.org/10.5194/egusphere-egu23-5684, 2023.

EGU23-5689 | Posters on site | GI6.1

Post-earthquake geoenvironmental changes in landslide-affected watersheds in Atsuma, Hokkaido (Japan) 

Yuichi S. Hayakawa, Tennyson Lo, Azim Zulhilmi, Xinyue Yu, and Xiaoxiao Wang

Following drastic changes in geoenvironmental components by coseismic landslides in mountainous watersheds, more gradual changes can be observed in the elements, including bare-land surface conditions, sediment connectivity, and vegetation recovery on sloping terrains. Such geoenvironmental changes may continue for years to decades, with complex interrelationships among various geomorphological and ecological factors. Their assessments are also crucial for local to regional environmental management. After the occurrence of numerous coseismic landslides triggered by the 2018 Hokkaido Eastern Iburi Earthquake in northern Japan, geomorphological and geoecological changes were explored using optical and laser sensors on uncrewed aerial systems. Morphological characteristics of the landslide-affected slopes in the watersheds were assessed with structure-from-motion multi-view stereo photogrammetry and light detection and ranging topographic datasets, while vegetation recovery on the slopes was examined with visible-light and near-infrared images. Although spatial relationships among morphological developments, sediment mobility, and vegetation recovery were not clearly observed, their general temporal trends may be correspondent. Dominant processes affecting the morphological developments are supposed to be frost heave in the cold climate and non-frequent high-intensity rainfalls, and these can be conditioning vegetation growth. Such local changes will be further examined on a wider, regional scale. 

How to cite: Hayakawa, Y. S., Lo, T., Zulhilmi, A., Yu, X., and Wang, X.: Post-earthquake geoenvironmental changes in landslide-affected watersheds in Atsuma, Hokkaido (Japan), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5689, https://doi.org/10.5194/egusphere-egu23-5689, 2023.

EGU23-5750 | Posters on site | GI6.1

Aseismic creep and coseismic dislocation at an active fault in volcanic area: the case of Ischia Island 

Stefano Carlino, Nicola Alessandro Pino, Lisa Beccaro, and Prospero De Martino

Understanding the fault dynamics in volcanic areas is not a simple task, mainly due to both the heterogeneity of volcanic structures and the local stress distribution. The presence of high temperature-high pressure geothermal fluids and relative high strain rates, and the occurrence of viscous processes in the deeper part of the volcano further contribute to generate complex patterns of strain load and release, possibly with aseismic creep and differential movements along the faults.

We present the case of an active fault located Casamicciola Terme town – in northern area of the volcanic caldera of Ischia Island (Southern Italy) – where repeated destructive earthquakes occurred at least since 1769, even causing thousands of victims in a single event, with the last one striking in 2017. To assess a possible mechanism leading to the activation of the Ischia main seismogenic fault, its cyclic nature and the related hazard, we performed a joined analysis of the ground vertical movements, obtained from cGPS (2001-present), DInSAR (2015-2018) time-series, and levelling data of the island (1987-2010). The geodetic data indicate that Casamicciola seismogenic fault is characterized by a complex dynamic, with some pre- and post-seismic aseismic dislocation, along sectors that move differentially, in response to the long-term subsidence of the island. Based on the ground deformation rate and on the distribution of degassing areas, we speculate that fluid pressure variations may have a major role in modulating the apparent non-stationarity of the Ischia stronger earthquakes. Furthermore, we suggest that a punctual monitoring of the distribution in space and time of the aseismic creep could provide clues on the state of strain of the seismogenic fault.

How to cite: Carlino, S., Pino, N. A., Beccaro, L., and De Martino, P.: Aseismic creep and coseismic dislocation at an active fault in volcanic area: the case of Ischia Island, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5750, https://doi.org/10.5194/egusphere-egu23-5750, 2023.

EGU23-6832 | ECS | Orals | GI6.1

Quantifying karstic geomorphologies using Minkowski tensors and graph theory: Applications to SLAM Lidar data from carbonate caves in Northern Bavaria (Germany) 

Rahul Prabhakaran, Ruaridh Smith, Daniel Koehn, Pierre-Olivier Bruna, and Giovanni Bertotti

Karstification is a ubiquitous feature in carbonate rocks. The origins can be hypogenic or epigenic based on the source of the reacting fluids. The presence of karstified lithologies and their spatial heterogeneity poses a major risk in subsurface energy utilization goals (hydrocarbons, geothermal etc). Such dissolution features tend to organize as spatial networks, with their evolution controlled by a complex interplay of several factors, including natural mineralogical variations in host rocks, effects of pre-existing structures, directional history of palaeo-flow paths, and competition between convective transport and dissolution. Accurate quantification of the spatial distribution of karst is difficult owing to resolution issues in 3D data such as seismic and ground penetrating radar. Recent advances in Simultaneous Location and Mapping (SLAM) Lidar technology have made possible to acquire karst cave passage geometries at very high-resolution with relative ease compared to conventional terrestrial lidar. In this contribution, we present a unique dataset of more than 80 caves, scanned using SLAM lidar, in Jurassic carbonates from northern Bavaria, Germany. We introduce a methodology for robustly deriving morphometrics of karstic caves using Minkowski tensors and spatial graph theory. The method is based on a combination representation of cave passage skeletons as spatial graphs and 2D passage cross-sections using Minkowski functionals. The enriched topological representation enables detailed analysis of internal spatial variation within a single cave and also comparison with cave geometries from other caves. We derive a typology of cave systems based on the degree of structural control on karstification using the database.

How to cite: Prabhakaran, R., Smith, R., Koehn, D., Bruna, P.-O., and Bertotti, G.: Quantifying karstic geomorphologies using Minkowski tensors and graph theory: Applications to SLAM Lidar data from carbonate caves in Northern Bavaria (Germany), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6832, https://doi.org/10.5194/egusphere-egu23-6832, 2023.

EGU23-7265 | Posters on site | GI6.1

Low Power, Rugged Edge Computing provides a low cost, powerful solution for on the ground remote sensing in extreme environments 

Nicholas Frearson, Terry Plank, Einat Lev, LingLing Dong, and Conor Bacon

Ground based remote sensing devices increasingly incorporate low cost single board computers such as a Raspberry Pi to capture and analyze images and data from the environment. Useful and cheap as these devices are, they are not designed for use in extreme conditions and as a consequence often suffer from early failure. Here we describe a system that incorporates a commercially available rugged Edge Computer running embedded Linux that is designed to operate in remote and extreme environments. The AVERT system  (Anticipating Volcanic Eruptions in  Real Time) developed at Columbia University in New York and funded by the Moore Foundation uses solar and wind powered Sensor nodes configured in a spoke and hub architecture currently operating on two volcanoes overseen by the Alaska Volcano Observatory in the Aleutian Islands, Alaska. Multiple Nodes distributed around the volcanoes are each controlled by an Edge Computer which manages and monitors local sensors, processes and parses their data via radio link to a central Hub and schedules system components to wake and sleep to conserve power. The Hub Edge Computer collects and assembles data from multiple Nodes and passes it via satellite, cellular modem or radio links to servers located elsewhere in the world or cloud for near real-time analysis. The local computer enables us to minimize local power demand to just a few watts in part due to the extremely low power sleep modes that are incorporated into these devices. For instance, a Node incorporating a webcam, IRCam, weather station, Edge Computer, network switch, communications radio and power management relays draws only 4.5W on average. In addition, this level of local computing power and a mature Linux operating environment enables us to run AI algorithms at source that process image and other data to flag precursory indicators of an impending eruption. This also helps to reduce data volume passed across the network at times of low network connectivity. We can also remotely interrogate any part of the system and implement new data schemes to best monitor and react to ongoing events. Future work on the AI algorithm development will incorporate local multisensor data analytics to enhance our anticipatory capability.

How to cite: Frearson, N., Plank, T., Lev, E., Dong, L., and Bacon, C.: Low Power, Rugged Edge Computing provides a low cost, powerful solution for on the ground remote sensing in extreme environments, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7265, https://doi.org/10.5194/egusphere-egu23-7265, 2023.

EGU23-8673 | Orals | GI6.1

Are they radon or random signals? Analysis of time series of 222Rn activity concentrations in populated areas of La Palma (Canary Islands, Spain) 

Antonio Eff-Darwich, Germán D. Padilla, José Barrancos, José A. Rodríguez-Losada, Pedro A. Hernández, Nemesio M. Pérez, Antonio J. Álvarez Díaz, Alexis M. González Pérez, Jesús García, José M. Santana, and Eleazar Padrón

Radon, 222Rn, is a radioactive constituent of the surface layer of the atmosphere. The analysis of the temporal and spatial variations in the flux of radon across the soil–air interface is a promising tool to study geo-dynamical processes. However, many of these variations are induced by external variables, such as temperature, barometric pressure, rainfall, or the location of the instrumentation, among others.

Anomalous CO2 degassing has been observed since the end of November 2021 in the neighborhoods of La Bombilla and Puerto Naos, located in the western flank of La Palma, about 5 km distance southwestern of the 2021 Tajogaite eruption vents (Hernández et al. 2022). In order to complement these observations with other independent parameters, a set of radon monitoring stations have been deployed in that area. In an attempt to filter out non-endogenous variations in the radon signal, we have implemented time-series numerical filtering techniques based on multi-variate and frequency domain analysis. A background level for radon emissions at various locations could therefore be defined, by which correlations between radon concentration, gaseous emissions and dynamical processes could be carried out. Some preliminary results corresponding to the first 3 months of data (october-december 2022) are presented.

Hernández, P. A., Padrón, E., Melián, G. V., Pérez, N. M., Padilla, G., Asensio-Ramos, M., Di Nardo, D., Barrancos, J., Pacheco, J. M., and Smit, M.: Gas hazard assessment at Puerto Naos and La Bombilla inhabited areas, Cumbre Vieja volcano, La Palma, Canary Islands, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7705, https://doi.org/10.5194/egusphere-egu22-7705, 2022.

How to cite: Eff-Darwich, A., Padilla, G. D., Barrancos, J., Rodríguez-Losada, J. A., Hernández, P. A., Pérez, N. M., Álvarez Díaz, A. J., González Pérez, A. M., García, J., Santana, J. M., and Padrón, E.: Are they radon or random signals? Analysis of time series of 222Rn activity concentrations in populated areas of La Palma (Canary Islands, Spain), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8673, https://doi.org/10.5194/egusphere-egu23-8673, 2023.

EGU23-8795 | ECS | Orals | GI6.1

Integration of Seismic and Quasi-Static Signals for Improved Volcanic Monitoring 

Joe Carthy, Alejandra Vásquez Castillo, Manuel Titos, Luciano Zuccarello, Flavio Cannavò, and M. Carmen Benitez

The time scale of ground displacement at volcanoes varies between short, sub second seismic events, to days, months or even years. This study is focused on data from seismic and GNSS stations located around Mount Etna. The GNSS and seismic stations operate at different time scales. Data from these different time scales is extracted and combined in order to better understand the subsurface dynamics. The overall aim of this research is to improve volcanic forecasting and monitoring. It does this in a novel way by applying signal processing and machine learning techniques to the rich dataset.

Mount Etna offers an interesting case study as it is a widely monitored volcano with a variety of sensors and with a rich pool of data to analyse. Additionally the volcanic dynamics at Mount Etna are complex. This is a volcano where there is a variety of different sub-surface dynamics due to the movement of both deep and shallow magma. This allows for rich insights to be drawn through the combination of different signal types.

This study looks at combining the information obtained from the seismic array at Mount Etna, with the information obtained from various GNSS stations on the volcano. The seismic array has been able to capture ground velocity data in the frequency range 0.025 Hz to 50 Hz from a range of stations at different locations across the volcano. The GNSS stations measure ground displacement with a sampling frequency of 1 Hz, and they allow for longer term ground dynamic analysis.

We analyse different seismic events, and relate the type and number of the seismic events to the long term ground deformation that we see in the recorded GNSS data. Where links between the two signal types have been identified, research is ongoing to establish a direct connection with known volcanic activity on Mount Etna. This will help establish what the relationship that we are seeing signifies. This integration of data from different types of sensors is a significant step into bridging the gap between seismic and quasi-static ground displacement at active volcanoes and should open the path toward more in depth volcanic monitoring and forecasting.

How to cite: Carthy, J., Vásquez Castillo, A., Titos, M., Zuccarello, L., Cannavò, F., and Benitez, M. C.: Integration of Seismic and Quasi-Static Signals for Improved Volcanic Monitoring, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8795, https://doi.org/10.5194/egusphere-egu23-8795, 2023.

EGU23-10069 | ECS | Orals | GI6.1

Vredefort impact site modelling through inhomogeneous depth weighted inversion. 

Andrea Vitale and Maurizio Fedi

We are showing an application of the 3D self-constrained depth weighted inversion of the inhomogeneous gravity field (Vitale and Fedi, 2020) of the Vredefort impact site.

This method is based on two steps, the first being the search in the 3D domain of the homogenous degree of the field, and the second being the inversion of the data using a power-law weighting function with a 3D variable exponent. It does not involve directly data at different altitudes, but it is heavily conditioned by a multiscale search of the homogeneity degree.

The main difference between this inversion approach and the one proposed by Li and Oldenburg algorithm (1996) and Cella and Fedi (2012) is therefore about the depth weighting function, whose exponent is a constant through the whole space in the original Li and Oldenburg and Cella and Fedi approaches, while it is a 3D function in the method which we will discuss here.

The model volume of the area reaches 20 km in depth, while along x and y its extension is respectively 41 by 63 km. The trend at low and middle altitudes of the estimated β related to the main structures is fitting the expectations because the results relate to two main structures, which are geometrically different: the core is like a spheroid body (β ≈ 3) and the distal rings are like horizontal pipes or dykes (1 < β < 2).

With a homogeneous depth weighting function, we recover a smooth solution and both the main sources, the main core and the rings of the impact, are still visible at the bottom of the model (20 km). This is not in agreement with the result by Henkel and Reimold (1996, 1998), which, based on gravity and magnetic inversion supported by seismic data, proposed a model where the bottom of the rings is around 10 km and the density contrast effect due to the core structure loses its effectiveness around 15 km.

Instead, using an inhomogeneous depth weighting function (figure 28) we can retrieve information regarding the position at depth of both core and distal ring structures that better fits the above model. In fact, the bottom of the distal ring structure, that should be around 10 km according to Henkel and Reimold (1996, 1998), is recovered very well using an inhomogeneous depth weighting function, while in the homogeneous case we saw that the interpreted structure was still visible at large depths.

In addition, also the core structure is shallower compared to the homogeneous approach and seems more reliable if we compare it with the model of Henkel and Reimold (1996, 1998).

Instead, the inhomogeneous approach presented in this paper leads naturally us to a better solution because it takes into account during the same inversion process of the inhomogeneous nature of the structural index within the entire domain.

How to cite: Vitale, A. and Fedi, M.: Vredefort impact site modelling through inhomogeneous depth weighted inversion., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10069, https://doi.org/10.5194/egusphere-egu23-10069, 2023.

EGU23-11065 | ECS | Posters on site | GI6.1

The Dynamics of Climate Change Science and Policy in Panama: A Review 

Gustavo Cárdenas-Castillero, Steve Paton, Rodrigo Noriega, and Adriana Calderón

The local studies and reports indicate that the temperature of Panama has increased by approximately 1°C since the 1970s. More evidence shows a constantly rising sea level in the Guna Yala archipelago, coral bleaching on both coasts, and increasingly more frequent and extreme precipitation events throughout Panama. This study includes an analysis of over 400 scientific publications made by researchers from multiple centres and more than 20 Panamanian official reports due to Panama's mandate and duties under the international climate accords. To summarise the results, the studies were gathered according to the climate change effects by Panamanian locations and analysed posteriorly using Rstudio and ArcMAP. The results indicate a significant increase in climate change research beginning in 2007.

This study identified and examined the essential findings per hydroclimatic region, showing the trends, limitations, collaborations, and international contributions. Climate change research in Panama includes some of the longest-term meteorological, hydrological, oceanographic, and biological studies in the neotropics. The most significant number of identified climate change-related studies were conducted, at least in part, in the Barro Colorado Natural Monument located in central Panama. Other frequently used sites include Metropolitan Natural Park, Soberania Park, the Panama Canal Watershed and the Caribbean coast of Colón and Bocas del Toro, primarily due to research conducted by Smithsonian Tropical Research-affiliated investigators. The tropical forests of Panama are some of the bests studied in the world; however, research has been concentrated in a relatively small number of locations and should be expanded to include additional areas to achieve a more complete and comprehensive understanding of climate change will impact Panama in the future.

How to cite: Cárdenas-Castillero, G., Paton, S., Noriega, R., and Calderón, A.: The Dynamics of Climate Change Science and Policy in Panama: A Review, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11065, https://doi.org/10.5194/egusphere-egu23-11065, 2023.

EGU23-12050 | Orals | GI6.1

Stress field analysis from induced earthquakes caused by deep fluid injection: the 2013 St. Gallen (Switzerland) seismic sequence. 

Bruno Massa, Guido Maria Adinolfi, Vincenzo Convertito, and Raffaella De Matteis

The city of St. Gallen is located in the Molasse Basin of northeast Switzerland. Mesozoic units of the substratum are affected by a fault system hosting a hydrothermal reservoir. In 2013 a deep geothermal drilling project started in an area close to the city. During a phase of reservoir stimulation, a sequence of more than 340 earthquakes was induced with a maximum magnitude ML 3.5. Stress inversion of seismological datasets became an essential tool to retrieve the stress field of active tectonics areas. With this aim, a dataset of the best constrained Fault Plane Solutions (FPSs) was processed in order to qualitatively retrieve stress-fields active in the investigated volume. FPSs were obtained by jointly inverting the long-period spectral-level P/S ratios and the P-wave polarities following a Bayesian approach (BISTROP). Data were preliminarily processed by the Multiple Inverse Method to evaluate the possible dataset heterogeneity and separate homogeneous FPS populations. The resulting dataset was then processed using the Bayesian Right Trihedra Method (BRTM). Considering that hypocentral depths range between 4.1 and 4.6 km b.s.l., in order to emphasize depth-related stresses, we performed a first step of raw stress inversion procedure splitting the data into five subsets, grouping events located inside 100-m depth ranges. Once the presence of stress variations with depth has been excluded, the second step of fine stress inversion procedure was performed on the entire dataset. The stress-inversion procedure highlights an active stress field dominated by a well-constrained NE low-plunging σ3 and a corresponding NW low-plunging σ1. The corresponding Bishop ratio confirms the stability of the retrieved attitudes. Results are in good accordance with the regional stress field derived from regional natural seismicity. Additionally, the retrieved, dominant, stress field is coherent with the regional tectonic setting.

This research has been supported by PRIN-2017 MATISSE project (No. 20177EPPN2).

How to cite: Massa, B., Adinolfi, G. M., Convertito, V., and De Matteis, R.: Stress field analysis from induced earthquakes caused by deep fluid injection: the 2013 St. Gallen (Switzerland) seismic sequence., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12050, https://doi.org/10.5194/egusphere-egu23-12050, 2023.

EGU23-13693 | ECS | Orals | GI6.1

Assessing the transfer factors (TFs) of contaminants from soil to plants: the case study of Campania region (Southern Italy) 

Lucia Rita Pacifico, Annalise Guarino, Gianfranco Brambilla, Antonio Pizzolante, and Stefano Albanese

The presence of potentially toxic elements (PTEs) derived from anthropogenic sources in soil represents a serious issue for animal and human health. These elements can easily move from the geological compartment to the biological compartment through to the food chain. (Jarup, 2003).

The geochemical knowledge of a territory allows to assess the degree of contamination of the environment, to locate the sources of environmental hazard and, possibly, to manage the anomalous concentrations of the PTEs in environmental matrices with the purpose of eliminating or minimizing their negative impact on the health of living beings. (Reimann et al. 2005).

Several studies have been already carried out to determine the distribution patterns of PTEs in the soil of Campania region (Southern Italy) (De Vivo et al., 2022) but little is known about the transfer processes of contaminants from soils to agricultural products.

In light of above, we present the results of a new study whose purpose was to determine the Transfer Factors (TFs) of PTEs from soil to a series of agricultural products commonly grown in Campania.

Considering the complex geological and geomorphological settings of the region and the diffuse presence of an historical anthropization related to the industry, agriculture, and urbanization, TFs were calculated for a relevant number of fruit and vegetable samples (3731 specimens). They were collected across the whole regional territory to detect differences between analysed species and to highlight the spatial changes in TFs occurring for individual species.

The TFs were calculated starting from the quasi-total (based on Aqua Regia leaching) and bioavailable (based on Ammonium Nitrate leaching) concentrations of PTEs in 7000 and 1500 soil samples, respectively.

Preliminary results show that TFs determined for the various agricultural species vary in space and in amount independently from the original elemental concentrations in soils. High values of TFs are found in areas where PTE concentrations in soil are low and vice versa, thus suggesting that multiple regression and multivariate analyses could be performed to investigate if some additional chemical and physical characteristics of soil (pH, grainsize, OM, etc.) could have a relevant weight on the transfer processes of contaminant from the soil to the plant life.

 

References

Järup L. 2003. Hazards of heavy metal contamination. Br. Med. Bull. 68, 167–182.

Reimann C., de Caritat P. 2005. Distinguishing between natural and anthropogenic sources for elements in the environment: regional geochemical surveys versus enrichment factors. Science of The Total Environment, Volume 337, Issues 1–3, pages 91-107.

De Vivo B. et al. 2022. Monitoraggio geochimico-ambientale dei suoli e dell'aria della Regione Campania. Piano Campania trasparente. Volume 4. Aracne Editore, Genzano di Roma.

How to cite: Pacifico, L. R., Guarino, A., Brambilla, G., Pizzolante, A., and Albanese, S.: Assessing the transfer factors (TFs) of contaminants from soil to plants: the case study of Campania region (Southern Italy), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13693, https://doi.org/10.5194/egusphere-egu23-13693, 2023.

EGU23-13853 | Posters on site | GI6.1

Analysis and Modelling of 2009-2013 vs. 2019-2022 Unrest Episodes at Campi Flegrei Caldera 

Raffaele Castaldo, Andrea Barone, De Novellis Vincenzo, Pepe Antonio, Pepe Susi, Solaro Giuseppe, Tizzani Pietro, and Tramelli Anna

Geodetic modelling is a significant procedure for detecting and characterizing unrest and eruption episodes and it represents a valuable tool to infer volume and geometry of volcanic source system.

In this study, we analyse the 2009–2013 and the ongoing 2019-2022 uplift phenomena at Campi Flegrei (CF) caldera in terms of spatial and temporal variations of the stress/strain field. In particular, we investigate the characteristics of the inflating sources responsible of these main deformation unrests occurred in the last twenty years. We separately perform for the two considered periods a 3D stationary Finite Element (FE) modelling of geodetic datasets to retrieve the geometry and location of the deformation sources. The geometry of FE domain takes into account both the topography and the bathymetry of the whole caldera. For what concern the definition of domain elastic parameters, we take into account the Vp/Vs distribution from seismic tomography. In order to optimize the nine model parameters (center coordinates, sferoid axes, dip, strike and over-pressure), we use the statistical random sampling Monte Carlo method by exploiting both geodetic datasets: the DInSAR measurements obtained from the processing of COSMO-SkyMed and Sentinel-1 satellite images. The modelling results for the two analysed period are compared revealing that the best-fit source is a three-axis oblate spheroid ~3.5 km deep, similar to a sill-like body. Furthermore, in order to verify the reliability of the geometry model results, we calculate the Total Horizontal Derivative (THD) of the vertical velocity component and compare it with those performed directly on the two DInSAR dataset.

Finally, we compare the modelled shear stress with the natural seismicity recorded during the 2000-2022 period, highlighting high values of modelled shear stress at depths of about 3.5 km, where high-magnitude earthquakes nucleate.

How to cite: Castaldo, R., Barone, A., Vincenzo, D. N., Antonio, P., Susi, P., Giuseppe, S., Pietro, T., and Anna, T.: Analysis and Modelling of 2009-2013 vs. 2019-2022 Unrest Episodes at Campi Flegrei Caldera, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13853, https://doi.org/10.5194/egusphere-egu23-13853, 2023.

EGU23-15127 | ECS | Orals | GI6.1

Multiscale magnetic modelling in the ancient abbey of San Pietro in Crapolla 

Luigi Bianco, Maurizio Fedi, and Mauro La Manna

We present a multiscale analysis of magnetic data in the archaeological site of San Pietro in Crapolla (Massa Lubrense, near Naples, Italy). The site consists of the ruins of an ancient abbey. We computed the Wavelet Transform of the Gradiometric measurements and decomposed the data at different scales and positions by a multiresolution analysis, allowing an effective extraction of local anomalies. Modelling of the filtered anomalies was performed by multiscale methods known as “Multiridge analysis” and “DEpth from eXtreme Points (DEXP)”.  The first method analyses a multiscale dataset at the zeroes of the first horizontal and vertical derivatives besides the potential field data themselves (ridges).  The Wavelet Transform Modulus Maxima  lines converged to buried remains. The field, scaled by a power law of the altitude (DEXP transformation) allowed estimates of source depths at its extreme points. The depth estimations for the buried structures obtained from the two methods are very close each other and fairly agree with those from the modelling of GPR anomalies. On the basis of these results, an archaeological excavation followed our indications and brought to light ancient walls.

How to cite: Bianco, L., Fedi, M., and La Manna, M.: Multiscale magnetic modelling in the ancient abbey of San Pietro in Crapolla, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15127, https://doi.org/10.5194/egusphere-egu23-15127, 2023.

EGU23-15190 | Orals | GI6.1

Synthetic aperture radar burst overlapped interferometry for the analysis of large ground instabilities: Experiments in volcanic regions. 

Antonio Pepe, Andrea Barone, Pietro Mastro, Pietro Tizzani, and Raffaele Castaldo

This work presents an overview of some applications of synthetic aperture radar (SAR) interferometry technology for the detection and analysis of large ground displacements occurring in volcanic areas, with the aim to retrieve the three-dimensional (3-D) ground displacement field (up-down, east-west, north-south). Specifically, the work summarizes and investigates the potential of Bursted Overlapped Interferometry (BOI) that properly combined can allow the retrieval, at different scales of resolution and accuracies, of the north-south components of the ground deformations, which are usually not available considering conventional SAR interferometry techniques. In this context, the almost global coverage and the weekly revisit times of the European Copernicus Sentinel-1 SAR sensors permit nowadays to perform extensive analyses with the aim to assess the accuracy of the BOI techniques. More recently, Spectral Diversity (SD) methods have been exploited for the fine co-registration of SAR data acquired with the Terrain Observation with Progressive Scans (TOPS) mode. In this case, considering that TOPS acquires images in a burst mode, there is an overlap region between consecutive bursts where the Doppler frequency variations is large enough to allow estimating and compensating for, with great accuracy, potential bursts co-registration errors. Additionally, and more importantly, in the case of non-stationary scenarios, it allows detecting the ground displacements occurring along the azimuthal directions (almost aligned along north-south) with centimeter accuracy. This is done by computing the difference between the right and left interferograms, i.e., the burst overlapped interferogram, and relating it to the ongoing deformation signals.

This work aims to apply the BOI technique in selected volcanic and seismic areas to evaluate the impact of this novel technology for the analysis of quantifying, over small, covered regions, the accumulated ground displacements in volcanic areas. In such regions, the interest is on quantifying the accuracy of integrated BOI systems for the retrieval of 3-D displacements. To this aim, we selected as a test site the Galapagos Island and we analyze with BOI the north-south ground displacements. At the next EGU symposium, the results of the BOI analyses will be presented, thus also providing comparative analyses with the results obtained from the use of potential field method applied on the ground displacements in volcanic areas. More specifically, by adopting this technique, we are able to estimate independently the north-south components of the ground displacement by exploiting the harmonic properties of the elasticity field.

How to cite: Pepe, A., Barone, A., Mastro, P., Tizzani, P., and Castaldo, R.: Synthetic aperture radar burst overlapped interferometry for the analysis of large ground instabilities: Experiments in volcanic regions., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15190, https://doi.org/10.5194/egusphere-egu23-15190, 2023.

EGU23-16132 | ECS | Orals | GI6.1

Multiscale imaging of low-enthalpy geothermal reservoir of the Phlegraean Fields caldera from gravity and resistivity data. 

Maurizio Milano, Giuseppe Cavuoto, Alfonso Corniello, Vincenzo Di Fiore, Maurizio Fedi, Nicola Massarotti, Nicola Pelosi, Michele Punzo, Daniela Tarallo, Gian Paolo Donnarumma, and Marina Iorio

The central‐eastern sector of the Phlegraean Fields caldera, southern Italy, is one of the most intensely studied and monitored volcanic active area of the word. This area reveals typical characters of a high‐ enthalpy geothermal systems. However, recently the presence of two different geothermal reservoirs has been outlined: one located in the central sector dominated by highly active vapours generated by episodic arrival of CO2‐rich magmatic fluids and the other one located in the eastern sector (Agnano zone) characterized by a shallow (400-500 m b.s.l.) still hot reservoir, heated by the upward circulation of deep no magmatic hot vapor.

In this study we present preliminary results deriving from the integration of different geophysical surveys carried out in the Agnano plain area, in the frame of the GEOGRID research project. We acquired high-resolution gravity data along two parallel profiles and we investigated the depth, shape and density contrast of the subsurface structures by the CompactDEXP (CDEXP) method, a multiscale iterative imaging technique based on the DEXP method. The resulting density models, together with DC resistivity and stratigraphic data, outlines the presence of a complex morphology of the Agnano subsoil characterized by a horst-graben structure. The importance of the structural lines identified by geophysical data, is also confirmed by the alignment of correlate outcropping thermal waters.

How to cite: Milano, M., Cavuoto, G., Corniello, A., Di Fiore, V., Fedi, M., Massarotti, N., Pelosi, N., Punzo, M., Tarallo, D., Donnarumma, G. P., and Iorio, M.: Multiscale imaging of low-enthalpy geothermal reservoir of the Phlegraean Fields caldera from gravity and resistivity data., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16132, https://doi.org/10.5194/egusphere-egu23-16132, 2023.

In the wake of Chernobyl and Fukushima accidents radiocesium has become a radionuclide of most environmental concern. The ease with which this radionuclide moves through the environment and is taken up by plants and animals is governed by its chemical forms and site-specific environmental characteristics. Distinctions in climate and geomorphology, as well as 137Cs speciation in the fallout result in differences in migration rates of 137Cs in the environment and rates of its natural attenuation. In Fukushima areas 137Cs was found to be strongly bound to soil and sediment particles, its bioavailability being reduced as a result.  Up to 80% of the deposited 137Cs on the soil were reported to be incorporated in hot glassy particles (CsMPs) insoluble in water. Disintegration of these particles in the environment is much slower than of Chernobyl-derived fuel particles. The higher annual precipitation and steep slopes in Fukushima contaminated areas are conducive to higher erosion and higher total radiocesium wash-off. Typhoons Etou in 2015 and Hagibis in 2019 demonstrated the pronounced redistribution of 137Cs on river watersheds and floodplains, and in some cases natural self-decontamination occurred. Among the common features in 137Cs behavior in Chernobyl and Fukushima is a slow decrease in 137Cs activity concentration in small, closed, and semi-closed lakes and its particular seasonal variations: increase in summer and decrease in winter.

How to cite: Konoplev, A.: Fukushima and Chernobyl: similarities and differences of radiocesium behavior in the soil-water environment, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1081, https://doi.org/10.5194/egusphere-egu23-1081, 2023.

After the Fukushima nuclear accident, atmospheric 134Cs and 137Cs measurements were taken in Fukushima city for 8 years, from March 2011 to March 2019. The airborne surface concentrations and deposition of radiocesium (radio-Cs) were high in winter and low in summer; these trends are the opposite of those observed in a contaminated forest area. The effective half-lives of 137Cs in the concentrations and deposition before 2015 (0.754 and 1.30 years, respectively) were significantly shorter than those after 2015 (2.07 and 4.69 years, respectively), which was likely because the dissolved radio-Cs was discharged from the local terrestrial ecosystems more rapidly than the particulate radio-Cs. In fact, the dissolved fractions of precipitation were larger than the particulate fractions before 2015, but the particulate fractions were larger after 2016. X-ray fluorescence analysis suggested that biotite may have played a key role in the environmental behavior of particulate forms of radio-Cs after 2014. 

Resuspension of 137Cs from the contaminated ground surface to the atmosphere is essential for understanding the long-term environmental behaviors of 137Cs. We assessed the 137Cs resuspension flux from bare soil and forest ecosystems in eastern Japan in 2013 using a numerical simulation constrained by surface air concentration and deposition measurements. In the estimation, the total areal annual resuspension of 137Cs is 25.7 TBq, which is equivalent to 0.96% of the initial deposition (2.68 PBq). The current simulation underestimated the 137Cs deposition in Fukushima city in winter by more than an order of magnitude, indicating the presence of additional resuspension sources. The site of Fukushima city is surrounded by major roads. Heavy traffic on wet and muddy roads after snow removal operations could generate superlarge (approximately 100 μm in diameter) road dust or road salt particles, which are not included in the model but might contribute to the observed 137Cs at the site.

The current presentation based on the two published papers: Watanabe et al., ACP, https://doi.org/10.5194/acp-22-675-2022 (2022) and Kajino et al., ACP, https://doi.org/10.5194/acp-22-783-2022 (2022). The presenters would like to thank all of the co-authors of the two papers for their significant contributions.

How to cite: Kajino, M. and Watanabe, A.: Eight-year variations in atmospheric radiocesium in Fukushima city and simulated resuspension from contaminated ground surfaces in eastern Japan, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1607, https://doi.org/10.5194/egusphere-egu23-1607, 2023.

EGU23-2540 | Posters on site | GI2.2

Hydrological setting control 137Cs and 90Sr concentration at headwater catchments in the Chornobyl Exclusion Zone 

Yasunori Igarashi, Yuichi Onda, Koki Matsushita, Hikaru Sato, Yoshifumi Wakiyama, Hlib Lisovyi, Gennady Laptev, Dmitry Samoilov, Serhii Kirieiev, and Alexei Konoplev

Concentration-discharge relationships are widely used to understand the hydrologic processes controlling river water chemistry. We investigated how hydrological processes affect radionuclide concentrations (137Cs and 90Sr) in surface water in the headwater catchment at the Chornobyl exclusion zone in Ukraine. In flat wetland catchment, the depth of saturated soil layer changed little throughout the year, but changes in saturated soil surface area during snowmelt and immediately after rainfall affected water chemistry by changing the opportunities for contact between suface water and the soil surface. On the other hand, slope catchments with little wetlands, the water chemistry in river water is formed by changes in the contribution of "shallow water" and "deep water" due to changes in the water pathways supplied to the river. Dissolved and suspended 137Cs concentrations did not correlate with discharge rate or competitive cations, but the solid/liquid ratio of 137Cs showed a significant negative relationship with water temperature, and further studies are needed in terms of sorption/desorption reactions. 90Sr concentrations in surface water were strongly related to water pathways for each the catchments. The contact between surface water and the soil surface and the change in the contribution of shallow and deep water to stream water could changes 90Sr concentrations in surface water for in wetland and slope catchments, respectively. In this study, we revealed that the radionuclide concentrations in rivers in Chornobyl is strongly affected by the water pathways at headwater catchments.

How to cite: Igarashi, Y., Onda, Y., Matsushita, K., Sato, H., Wakiyama, Y., Lisovyi, H., Laptev, G., Samoilov, D., Kirieiev, S., and Konoplev, A.: Hydrological setting control 137Cs and 90Sr concentration at headwater catchments in the Chornobyl Exclusion Zone, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2540, https://doi.org/10.5194/egusphere-egu23-2540, 2023.

EGU23-2561 | Posters on site | GI2.2

Dispersion of particle-reactive elements caused by the phase transitions in scavenging 

Kyeong Ok Kim, Vladimir Maderich, Igor Brovchenko, Kyung Tae Jung, Sergey Kivva, Katherine Kovalets, and Haejin Kim

A generalized model of scavenging of the reactive radionuclide 239,240Pu was developed, in which the sorption-desorption processes of oxidized and reduced forms on multifraction suspended particulate matter are described by first-order kinetics. One-dimensional transport-diffusion-reaction equations were solved analytically and numerically. In the idealized case of instantaneous release of 239,240Pu on the ocean surface, the profile of concentrations asymptotically tends to the symmetric spreading bulge in the form of a Gaussian moving downward with constant velocity. The corresponding diffusion coefficient is the sum of the physical diffusivity and the apparent diffusivity caused by the reversible phase transitions between the dissolved and particulate states. Using the method of moments, we analytically obtained formulas for both the velocity of the center mass and apparent diffusivity. It was found that in ocean waters that have oxygen present at great depths, we can consider in the first approximation a simplified problem for a mixture of forms with a single effective distribution coefficient, as opposed to considering the complete problem. This conclusion was confirmed by the modeling results for the well-ventilated Eastern Mediterranean. In agreement with the measurements, the calculations demonstrate the presence of a maximum that is slowly descending for all forms of concentration. The ratio of the reduced form to the oxidized form was approximately 0.22-0.24. At the same time, 239,240Pu scavenging calculations for the anoxic Black Sea deep water reproduced the transition from the oxidized to reduced form of 239,240Pu with depth in accordance with the measurement data.

How to cite: Kim, K. O., Maderich, ., Brovchenko, ., Jung, . T., Kivva, ., Kovalets, ., and Kim, .: Dispersion of particle-reactive elements caused by the phase transitions in scavenging, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2561, https://doi.org/10.5194/egusphere-egu23-2561, 2023.

EGU23-3049 | ECS | Posters on site | GI2.2

Changes in Air Dose Rates due to Soil Water Content in Forests in Fukushima Prefecture, Japan 

Miyu Nakanishi, Yuichi Onda, Hiroaki Kato, Junko Takahashi, Hikaru Iida, and Momo Takada

Radionuclides released and deposited by the 2011 Fukushima Daiichi Nuclear Power Plant accident caused an increase in air dose rates in forests in Fukushima Prefecture. It has been reported that air dose rates increase during rainfall, but we found that air dose rates decreased during rainfall in forests in Fukushima. This is said to be due to the shielding effect of soil moisture. This study aimed to develop a method for estimating changes in air dose rates due to rainfall even in the absence of soil moisture data. Therefore, we used the preceding rainfall (Rw), an indicator that also takes into account past rainfall; we calculated Rw in Namie-Town, Futaba-gun, Fukushima Prefecture from May to July 2020, and estimated air dose rates. In this area, air dose rates decreased with increasing soil moisture. Furthermore, air dose rates could be estimated by combining Rw with a half-life of 2 hours and 7 days, and by considering hysteresis in the absorption and drainage processes. The coefficient of determination (R2) exceeded 0.70 for the estimation of soil water content at this time. Furthermore, good agreement was also observed in the estimation of air dose rates from Rw (R2 > 0.65). The same method was used to estimate air dose rates at the Kawauchi site from May to July 2019. Due to the high water repellency of the Kawauchi site, the increase in soil water content was very small and the change in air dose rate was almost negligible when soil water content was less than 15% and rainfall was less than 10 mm. This study enabled the estimation of soil water content and air dose rate from rainfall and captured the effect of rainfall on the decreasing trend of air dose rate. Therefore, in the future, This study can be used as an indicator to determine whether temporary changes in air dose rates are caused by influences other than rainfall. This study also contributes to the improvement of methods for estimating external dose rates for humans and terrestrial animals and plants in forests.

How to cite: Nakanishi, M., Onda, Y., Kato, H., Takahashi, J., Iida, H., and Takada, M.: Changes in Air Dose Rates due to Soil Water Content in Forests in Fukushima Prefecture, Japan, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3049, https://doi.org/10.5194/egusphere-egu23-3049, 2023.

Wet scavenging modeling remains a challenge of the atmospheric transport of 137Cs following the Fukushima Daiichi Nuclear Power Plant accident, which significantly influences the detailed spatiotemporal 137Cs distribution. Till now, numerous wet deposition schemes have been proposed for 137Cs, but it is often difficult to evaluate them consistently, due to the limited resolution of meteorological field data and detailed differences in model implementations. This study evaluated the detailed behavior of 25 combinations of in- and below-cloud wet scavenging models in the framework of the Weather Research and Forecasting-Chemistry model, using high-resolution (1 km × 1 km) meteorological input. The above implementation enables consistent evaluation with great details, revealing complex local behaviors of these combinations. The 1-km-resolution simulations were compared with simulations obtained previously using 3-km-resolution meteorological field data, with respect to the rainfall pattern of the east Japan during the accident, atmospheric concentrations acquired at the regional SPM monitoring sites and the total ground deposition. The capability of these models in reproducing local-scale observations were also investigated with a local-scale observations at the Naraha site, which his only 17.5 km from the Fukushima Daiichi Nuclear Power Plant. The performance of the ensemble mean was also evaluated. Results revealed that the 1-km simulations better reproduce the cumulative rainfall pattern during the Fukushima accident than those revealed by the 3-km simulations, but showing with spatiotemporal variability in accuracy. And rainfall below 1 mm/h is critical for the simulation accuracy. Those single-parameter wet deposition models that rely solely on the rainfall showed improvements in performance in the 1-km simulations relative to that in the 3-km simulations, because of the improved rainfall simulation in the 1-km results. Those multiparameter models that rely on both cloud and rainfall showed more robust performance in both the 3-km and -1km simulations, and the Roselle–Mircea model presented the best performance among the 25 models considered. Besides rainfall, wind transport showed substantial influence on the removal process of atmospheric 137Cs, and it was nonnegligible even during periods in which wet deposition was dominant. The ensemble mean of the 1-km simulations better reproduces the high deposition area and the total deposition amount is closer to the observations than the 3-km simulation. At the local scale, the 1-km-resolution simulations effectively reproduced the 137Cs concentrations observed at the Naraha site, but with deviations in peak timing, mainly because of biased wind direction. These findings indicate the necessity of a multi-parameter model for robust regional-scale wet deposition simulation and a refined wind and dispersion model for local-scale simulation of 137Cs concentration.

How to cite: Zhuang, S., Dong, X., Xu, Y., and Fang, S.: Modeling and sensitivity study of wet scavenging models for the Fukushima accident using 1-km-resolution meteorological field data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4152, https://doi.org/10.5194/egusphere-egu23-4152, 2023.

EGU23-4697 | ECS | Orals | GI2.2

Quantifying the riverine sources of sediment and associated radiocaesium deposited off the coast of Fukushima Prefecture 

Pierre-Alexis Chaboche, Wakiyama Yoshifumi, Hyoe Takata, Toshihiro Wada, Olivier Evrard, Toshiharu Misonou, Takehiko Shiribiki, and Hironori Funaki

The Fukushima-Daiichi Nuclear Power Plant (FDNPP) accident trigged by the Great East Japan Earthquake and subsequent tsunami in March 2011 released large quantities of radionuclides in terrestrial and marine environments of Fukushima Prefecture. Although radiocaesium (i.e. 134Cs and 137Cs) activity in these environments has decreased since the accident, the secondary inputs via the rivers draining and eroding the main terrestrial radioactive plume were shown to sustain high levels of 137Cs in riverine and coastal sediments, which are likely deposited off the coast of the Prefecture. Accordingly, identifying the sources of sediment is required to elucidate the links between terrestrial and marine radiocaesium dynamics and to anticipate the fate of persistent radionuclides in the environment.

The objective of this study is to develop an original sediment source tracing technique to quantify the riverine sources of sediment and associated radionuclides accumulated in the Pacific Ocean. Target coastal sediment cores (n=6) with a length comprised between 20 and 60cm depth were collected during cruise campaigns between July and September 2022 at the Ota (n=2), Niida (n=1) and Ukedo (n=3) river mouths. Prior to gamma spectrometry measurements, sediment cores were opened and cut into 2 cm increments, oven-dried at 50°C for at least 48 hours, ground and passed through a 2-mm sieve.

Preliminary results regarding the spatial and depth distribution of radiocaesium in these samples show a strong heterogeneity, with highest radiocaesium levels (up to 134 ± 2 and 4882 ± 11 Bq kg-1 for 134Cs and 137Cs, respectively) found in coastal sediment cores located at the Ukedo river mouth. On the opposite, no trace or low levels of Fukushima-derived radiocaesium were found in the Niida and in one sediment core of the Ota River mouths. Additional measurements will be conducted to determine the physico-chemical properties of this sediment, in order to select the optimal combination of tracers, which will then be introduced into un-mixing models. This increase knowledge will undoubtedly be useful for watershed and coastal management in the FDNPP post-accidental context.

How to cite: Chaboche, P.-A., Yoshifumi, W., Takata, H., Wada, T., Evrard, O., Misonou, T., Shiribiki, T., and Funaki, H.: Quantifying the riverine sources of sediment and associated radiocaesium deposited off the coast of Fukushima Prefecture, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4697, https://doi.org/10.5194/egusphere-egu23-4697, 2023.

EGU23-4925 | Posters on site | GI2.2

Verification of reproductivity of 137Cs activity concentration in the database by an ocean general circulation model 

Daisuke Tsumune, Frank Bryan, Keith Lindsay, Kazuhiro Misumi, Takaki Tsubono, and Michio Aoyama

Radioactive cesium (137Cs) is distributed in the global ocean due to global fallout from atmospheric nuclear tests, release from reprocessing plants in Europe, and supply to the ocean due to the Fukushima Daiichi Nuclear Power Plant accident. In order to detect future contamination by radionuclides, it is necessary to understand the global distribution of radionuclides such as 137Cs. For this purpose, the IAEA is compiling a database of observation results (MARIS). However, since the spatio-temporal densities of observed data vary widely, it is difficult to obtain a complete picture from the database alone. Comparative validation using ocean general circulation model (OGCM) simulations is useful in interpreting these observations, and global ocean general circulation model (CESM2, POP2) simulations were conducted to clarify the behavior of 137Cs in the ocean. The horizontal resolution is 1.125° longitude and 0.28° to 0.54° latitude. The minimum spacing near the sea surface is 10 m, and the spacing increases with depth to a maximum of 250 m with 60 vertical levels. Climatic values were used for driving force. As a source term for 137Cs to the ocean, atmospheric fallout from atmospheric nuclear tests was newly established based on rainfall data and other data, and was confirmed to be more reproducible than before. Furthermore, the release from reprocessing plants in Europe and the leakage due to the accident at the Fukushima Daiichi Nuclear Power Plant were taken into account. 2020 input conditions were assumed to continue after 2020, and calculations were performed from 1945 to 2030. The simulated 137Cs activities were found to be in good agreement, especially in the Atlantic and Pacific Oceans, where the observed densities are large. On the other hand, they were underestimated in the Southern Hemisphere, suggesting the need for further improvement of the fallout data. 137Cs concentrations from the Fukushima Daiichi Nuclear Power Plant accident in March 2011 were generally in good agreement, although the reproducibility remained somewhat problematic due to insufficient model resolution. In other basins, the concentration characteristics were able to be determined, although the observed values were insufficient. Radioactivity concentrations of atmospheric nuclear test-derived 137Cs may continue to be detected in the global ocean after 2030. The results of this simulation are useful for planning future observations to fill the gaps in the database.

How to cite: Tsumune, D., Bryan, F., Lindsay, K., Misumi, K., Tsubono, T., and Aoyama, M.: Verification of reproductivity of 137Cs activity concentration in the database by an ocean general circulation model, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4925, https://doi.org/10.5194/egusphere-egu23-4925, 2023.

EGU23-4947 | ECS | Posters on site | GI2.2

Vertical distribution of radioactive cesium-rich microparticles in forest soil of Hamadori area, Fukushima Prefecture 

Takahiro Tatsuno, Hiromichi Waki, Naoto Nihei, and Nobuhito Ohte

A lot of radionuclides were scattered after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Previous studies showed that there were FDNPP-derived radioactive cesium-rich microparticles (CsMPs) with the size of a few μm in the soil and river water around Fukushima Prefecture[1]. CsMPs have high radioactive cesium (Cs) concentration per unit mass, therefore they can be one of the factor in overestimating the Cs concentration in samples. Because Cs in CsMPs may not react directly with clay particles unlike the Cs ion in liquid phase, it is considered that CsMPs work as Cs carrier in soils[2]. However, unlike ionic Cs and Cs adsorbed onto clay particles, the distribution and dynamics of CsMPs in soils have not been clarified. In this study, we investigated vertical distribution of CsMPs in the forest soil and the soil properties in Fukushima Prefecture, Japan.

Soil samples were collected from the forest in the difficult-to-return zone, approximately 10 km away from the FDNPP. The undisturbed soil samples were collected from 0-35 cm soil depth at 5 cm intervals using core sampler to investigate soil properties. Furthermore, litter samples on the surface soil layer were collected. Using these samples, the vertical distribution of Cs concentration in the soil and Cs derived from CsMPs were investigated. Cs concentration in samples placed in 100 mL of U8 container was measured using a germanium semiconductor detector. Cs derived from CsMPs was evaluated using an Imaging plate with reference to the method ffor quantification of CsMPs[3].

Like Cs adsorbed on the soil, CsMPs were also mostly distributed in the soil surface layer between o and 5 cm of soil depth. We considered that straining may be one of the mechanism of CsMPs retention on the soil surface. Bradford et al. (2006) [4] showed that straining might be a significant mechanism for colloid retention when the average particle size in the porous medium is less than 200 times larger than the colloidal particle size. In this study, assuming the CsMPs size of approximately 1 µm, the average particle size of the soil collected from surface layer 0-5 cm was less than 200 times that of CsMPs. However, the average particle size decreased in deeper layer than 5 cm, therefore, it was considered that straining mechanism could be stronger.

This work was supported by FY2022 Sumitomo Foundation and FY2022 Internal Project of Institute of Environmental Radioactivity, Fukushima University.

 

References

[1] Igarashi, Y. et al., 2019. J. Environ. Radioact. 205–206, 101–118.

[2]  Tatsuno, T et al., 2022. J. Environ. Manage. 329, 116983.

[3] Ikehara et al., 2018. Environ. Sci. Technol. 52, 6390–6398.

[4] Bradford et al., 2003. Environ. Sci. Technol. 37, 2242–2250.

How to cite: Tatsuno, T., Waki, H., Nihei, N., and Ohte, N.: Vertical distribution of radioactive cesium-rich microparticles in forest soil of Hamadori area, Fukushima Prefecture, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4947, https://doi.org/10.5194/egusphere-egu23-4947, 2023.

EGU23-5042 | ECS | Posters on site | GI2.2

Changes in 90Sr transport dynamics in groundwater after large-scale groundwater drawdown in the vicinity of the cooling pond at the Chornobyl Nuclear Power Plant 

Hikaru Sato, Naoaki Shibasaki, Maksym Gusyev, Yuichi Onda, and Dmytro Veremenko

Migration of long-lived radioactive 90Sr introduced by nuclear accidents and radioactive waste requires long-term monitoring and protection management due to its half-life of 28.8 years and high mobility in water. Presently, 37 years have passed since the largest worldwide 90Sr contamination was released and deposited around the Chornobyl Nuclear Power Plant (ChNPP). In the vicinity of the ChNPP, the water level of the cooling pond (CP) has declined since May 2014 following the decommissioning phase of the Unit 3 reactor. The drawdown of the CP lowered the groundwater level in a massive vicinity (about 70 km2), and the change in the groundwater system due to the drawdown has caused concerns about possible changes in 90Sr concentrations in water and transport dynamics to the Pripyat River. Therefore, this study evaluated how 90Sr transport dynamics were influenced due to changes in the groundwater flow system from 2011 to 2020 based on observed data and results of the groundwater flow simulation in the CP vicinity.

The numerical simulation was conducted from 2011 to 2020 on monthly time-step using USGS MODFLOW with PM11 GUI and calibrated to groundwater heads measured at monitoring wells. In the location between the CP and the Pripyat River, estimated pore velocities near the river were reduced compared to velocities before the CP drawdown due to the decrease in the hydraulic gradient between the CP and the river. Decrease in groundwater velocity results decrease in groundwater discharge and delay of 90Sr transport. Therefore, the amount of 90Sr transported from the CP to the river is smaller than the period prior to the CP drawdown. The reduced 90Sr transport is expected to have less impact on the radioactivity in the river water even in the Pripyat River floodplain northwest of the CP where 90Sr concentrations significantly increased after the CP drawdown. In addition, the measured and simulated changes in groundwater flow direction and velocity suggested the possibility of 90Sr accumulation at the floodplain caused by stagnant groundwater from reduced velocity and additional 90Sr infiltration from surrounding ponds located at the Pripyat River floodplain. Therefore, enhancing the current monitoring of 90Sr concentrations near the floodplain would be needed for long-term monitoring and protection management to prevent the risk.

How to cite: Sato, H., Shibasaki, N., Gusyev, M., Onda, Y., and Veremenko, D.: Changes in 90Sr transport dynamics in groundwater after large-scale groundwater drawdown in the vicinity of the cooling pond at the Chornobyl Nuclear Power Plant, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5042, https://doi.org/10.5194/egusphere-egu23-5042, 2023.

The 3D model THREETOX was applied for the long-term simulation of the planned release of radioactively contaminated water from Fukushima storage tanks to marine environment. Two radionuclides were considered: 3H that has the largest activity in tanks and 129I that can caused the largest dose of radiation to human. The constant release rate of 3H equal to 22 TBq/y according to TEPCO estimations and the constant release rate of 129I equal to 361 MBq/y according to estimations from the current study were used in the simulations.

The THREETOX model used monthly averaged currents from the KIOST-MOM model. A dynamic food web model was included in the THREETOX model. In the model, organisms uptake the activity directly from water and through the food chain. The food chain consists of phytoplankton, zooplankton, non-piscivorous (prey) fish, and piscivorous (predatory) fish. In case of 129I, macro-algae was also considered. The modelling area covers Fukushima coastal waters and extends for 1600 km from the coast to the East. From North to South this area extends for 1300 km.

From model results, we can see how contamination will spread along the coast in different seasons. For example, in summer time the currents near the coast are directed to the North that leads to contamination of the Sendai Bay. This means that at different points along the coast, the concentration of radionuclides can periodically change according to currents that change during the year. Calculated concentrations of activity at several points along the coast of Japan, which correspond to largest cities in the area of interest, were extracted from model results. For example, calculated concentration of 3H in water in Tomioka point, which is quite close to FDNPP, sometimes can exceed 200 Bq/m3. In Soma point, the concentration will exceed 50 Bq/m3, while in point Iwaki-Onahama – 20 Bq/m3 at some moments of time. In other points, the calculated concentration of 3H in water will not exceed 10 Bq/m3 that is less than background concentration 50 Bq/m3. Concerning 129I, its maximum concentration in water will be around 10-3 – 10-2 Bq/m3 in points close to FDNPP and around 10-4 Bq/m3 in points further from the NPP that is around 100 000 times less than the calculated concentrations of 3H.

Calculated concentrations of OBT (organically bounded tritium) in predatory and prey fish are less than 0.01 Bq/kg in all points except FDNPP point where it is around 0.02 Bq/kg. This value is 10 times less than measured concentration of OBT in fish (0.2 Bq/kg) that was made in 2014 in the coastal area near the damaged NPP. Calculated concentrations of 129I in predatory and prey fish are in the range 10-6 – 10-4 Bq/kg in all considered points. Concentrations of 129I in macro-algae are about 100 times higher due to ability of iodine to accumulate in macro-algae. 

How to cite: Bezhenar, R., Takata, H., and Maderich, V.: Transport of H-3 and I-129 in water and their uptake by marine organisms due to the planned release of Fukushima storage water, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6019, https://doi.org/10.5194/egusphere-egu23-6019, 2023.

EGU23-6026 | Orals | GI2.2

Dynamic change of dissolved Cs-137 from headwaters to downstream in the Kuchibuto River catchment 

Yuichi Onda, Taichi Kawano, Keisuke Taniguchi, and Junko Takahashi

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on March 11, 2011 resulted in the release of large amounts of radioactive cesium-137 (137Cs) into the environment. It is important to characterize the Cs-137 dynamics throughout the river from the headwaters to the downstream. Previous studies have suggested the importance of dissolved forms of Cs-137 in organic matter in small watersheds and dissolved forms in suspended solids in large watersheds. Since the concentration of suspended-form Cs has been shown to decrease significantly after decontamination in evacuated areas (Feng et al. 2022), this rapid decrease in suspended-form Cs-137 concentration can be used to determine the cause of dissolved-form Cs. Therefore, we attempted to evaluate whether the dissolved Cs-137 was derived from organic matter or suspended solids by comparing data before and after decontamination.

 The objective of this study is to compare the decreasing trends of Cs-137 concentrations in decontaminated and undecontaminated areas based on long-term monitoring of suspended solids, dissolved solids, and coarse organic matter Cs-137 concentrations since 2011. The study area includes four headwater basins and four river basins (eight sites in total) in the Kuchibuto River watershed in the Yamakiya district of Fukushima Prefecture, located approximately 35 km northwest of the FDNPP.

In the Kuchibuto River watershed, a large inflow of decontaminated soil with low Cs-137 concentrations due to an increase in the amount of bare land caused by decontamination resulted in a rapid decrease in the concentration of suspended-form 137Cs in the decontaminated area in the headwaters and in the upper reaches of the river. However, no clear effect of decontamination was observed in the concentrations of dissolved Cs-137 and Cs-137 in coarse organic matter. Comparison of the slopes of Cs-137 concentrations in the suspended, dissolved, and coarse organic matter showed that the slope of the dissolved form was similar to that of the coarse organic matter in the source watersheds, and similar to that of the SS in the downstream watersheds. These results suggest that the contribution of dissolved Cs-137 from organic matter in small watersheds and that from suspended solids in large watersheds is significant.

How to cite: Onda, Y., Kawano, T., Taniguchi, K., and Takahashi, J.: Dynamic change of dissolved Cs-137 from headwaters to downstream in the Kuchibuto River catchment, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6026, https://doi.org/10.5194/egusphere-egu23-6026, 2023.

EGU23-10093 | Posters on site | GI2.2

Riverine 137Cs dynamics and remoralization in coastal waters during high flow events 

Yoshifumi Wakiyama, Hyoe Takata, Keisuke Taniguchi, Takuya Niida, Yasunori Igarashi, and Alexei Konoplev

Understanding riverine 137Cs dynamics during high-flow events is crucial for improving predictability of 137Cs transportation and relevant hydrological responses. It is frequently documented that the majority of 137Cs is exported during high-flow events triggered by intensive rainfall. Studies on 137Cs in coastal seawater suggested that a huge high-flow events resulted in high dissolved 137Cs concentration in seawater. Different temporal patterns of 137Cs concentrations in river water are found in the existing literature on 137Cs dynamics during high-flow events. Although such differences may reflect catchment characteristics, there is no comprehensive analysis for the relationships. This study explores catchment characteristics affecting 137Cs transport via river to ocean based on datasets obtained by sampling campaigns during high-flow events. 137Cs datasets obtained at 13 points in 6 river water systems were subject to the analysis. The analyses intended to explore relationship between catchment characteristics (scale and land use composition) and 137Cs dynamics in terms of variations in concentration, fluxes, and potential remobilization in seawater. We could not find any significant correlations between the parameters of catchment characteristics and mean values of normalized concentrations of 137Cs and apparent Kd. However, when approximating 137Cs concentrations and Kd value as a power function of suspended solid concentration (Y=α X^β), the power of β in the equations for dissolved 137Cs concentration and Kd showed negative and positive correlations with the logarithm of the watershed area, respectively, and the positive β was found when the catchment area was on the order of 100 km2 or larger and vice versa. This indicates that the concentration of dissolved 137Cs tends to decrease with increased water discharge in larger catchments for smaller catchments. These results suggest that the temporal pattern of dissolved 137Cs concentrations depends on watershed scale. 137Cs flux during a single event ranged from 1.9 GBq to 1.1 TBq and accounted for 0.00074% to 0.22% of total 137Cs deposited in relevant catchments. Particulate 137Cs flux accounted for more than 92% of total 137Cs flux, except for Ukedo River basin with a large dam reservoir. R-factor, an erosivity index in the Universal Soil Loss Equation model family, is a good parameter for reproducing sediment discharge and particulate 137Cs flux. Efficiency of particulate 137Cs flux, calculated by dividing the flux by R-factor of event, tended to be high in catchments with relatively low forest cover. Desorption ratio of 137Cs, obtained by 1-day shaking experiment of SS in seawater, ranged from 2.8 to 6.6%. The ratio was almost proportional of ratio of exchangeable 137Cs. The estimated amounts of desorbed 137Cs, obtained by multiplying particulate 137Cs and the desorption ratios, were greater than direct flux of dissolved 137Cs. Reanalysis of riverine 137Cs dataset in high flow events is revealing relationship between catchment characteristics and 137Cs dynamics. Further analyses, such as evaluation of decontamination impacts and inter-catchment comparisons of 137Cs fluxes, are required for better understanding.

How to cite: Wakiyama, Y., Takata, H., Taniguchi, K., Niida, T., Igarashi, Y., and Konoplev, A.: Riverine 137Cs dynamics and remoralization in coastal waters during high flow events, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10093, https://doi.org/10.5194/egusphere-egu23-10093, 2023.

EGU23-10539 | Posters on site | GI2.2 | Highlight

Long-term dynamics of 137Cs accumulation at an urban pond 

Honoka Kurosawa, Kenji Nanba, Toshihiro Wada, and Yoshifumi Wakiyama

It is known that the semi-enclosed water area such as pond and dam reservoir is readily subject to 137Cs accumulation because of the secondary inflow from the catchment area. We present the long-term monitoring data of the 137Cs concentration in bottom sediment and pond water in an urban pond located in the central area of Koriyama City, Fukushima Prefecture to discuss the 137Cs dynamics of the urban pond. The pond was decontaminated by the bottom sediment removal in 2017. The bottom sediment core and pond water were collected in 2015 and 2018-2021. The inflow and outflow water were collected in 2020-2021. The river water around the pond was collected in 2021. The bottom sediment and water samples were measured for 137Cs concentration, particulate size distribution, and N and C stable isotopes. Compared between 2015 and 2018, the 137Cs inventory and 0-10 cm depth of 137Cs concentration in the bottom sediment at 7 points were decreased by 81 % (mean 1.50 to 0.28 MBq/m2) and 85 % (mean 31.5 to 4.8 kBq/kgDW), respectively. Although mean 137Cs inventory in bottom sediment did not drastically change during 2018-2021, its variability became wider. Points with increased 137Cs inventory in bottom sediment showed year-by-year increase in thickness of layer with concentrations higher than 8 kBq/kgDW, a criterion for considered decontamination. The 137Cs concentration in suspended solids (SS) in pond water was lowered after decontamination, although it still remained above 8 kBq/kgDW. The 137Cs concentrations in SS of inflow water were also high, exceeding 8 kBq/kgDW. The 137Cs concentration in SS of the river water around the pond was higher when it passed through the urban area, suggesting that the inflow of particles from urban origin maintained high 137Cs level in the pond. 

How to cite: Kurosawa, H., Nanba, K., Wada, T., and Wakiyama, Y.: Long-term dynamics of 137Cs accumulation at an urban pond, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10539, https://doi.org/10.5194/egusphere-egu23-10539, 2023.

EGU23-10868 | Posters on site | GI2.2

Estimation of annual Cesium-137 influx from the FDNPP to the coastal water 

Shun Satoh and Hyoe Takata

Due to the accident at the Fukushima Daiichi Nuclear Power Plant (1F) in March 2011, radionuclides were introduced into the environment, and one of the release pathways to the ocean is the direct discharge from the 1F (on-going release). This was mainly caused immediately after the accident, but even now, the on-going release is continuing. In this study, firstly we estimated the on-going release of 137Cs from 1F over 10 years after the accident, using the TEPCO’s 137Cs monitoring results in the coastal area around 1F. Secondly, change in the monitoring data related to countermeasures by TEPCO (e.g. construction of iced walls) to reduce the introduction of contaminated water into the ocean or detect 137Cs in nearby seawater, so their effects on the on-going release estimation were also discussed. A box model including inside and outside of the port was assumed for the area around 1F, and the amount of 137Cs in the box was estimated (estimated value: modeled data). Then, the difference between the estimated value and the amount of 137Cs obtained from actual observed concentrations (measured value: monitoring data) was calculated. The result showed that the measured value was higher than the estimated value, suggesting the on-going release from 1F. As for decrease in monitoring data after the countermeasures, it is implied that the estimation of rate of on-going release has been reduced by the countermeasures.

How to cite: Satoh, S. and Takata, H.: Estimation of annual Cesium-137 influx from the FDNPP to the coastal water, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10868, https://doi.org/10.5194/egusphere-egu23-10868, 2023.

EGU23-11671 | Posters on site | GI2.2

Changes in Cs-137 concentrations in river-bottom sediments and their factors in Fukushima Prefecture rivers 

Naoyuki Wada, Yuichi Onda, Xiang Gao, and Chen Tang

The Fukushima Daiichi Nuclear Power Plant accident (FDNPP) in 2011 resulted in the release of large amounts of Cs-137 into the atmosphere. Cs-137 deposited on land was mainly distributed in forests, but some of it has been discharged to the sea through rivers. The dissolved and suspended forms of Cs-137 in rivers have been focused on, and it is known that the discharge mechanism and concentration formation of Cs-137 differ depending on the land use in the river basin. On the other hand, there are few cases that focus on the dynamics of Cs-137 in river bottom sediments. River-bottom sediment is less likely to flow downstream than suspended sediments, so contamination in the downstream area may be long-term.
We will clarify the migration mechanism of Cs-137 in rivers including river-bottom sediment.Therefore, we will analyze data collected from 2011 to 2018 in 89 watersheds in Fukushima prefecture. In analyzing the data, we removed sampling points with brackish water using electrical conductivity and corrected for particle size to standardize the surface area of particles that absorb Cs-137.As a result, it was found that unlike dissolved and suspended forms, the Cs concentration in river-bottom sediments can increase within the initial year. This is related to the average initial deposition in the watershed and the amount of initial deposition at the river-bottom sediment sampling sites, with a tendency to increase with relatively higher initial deposition in the upstream area. It was also known that the decrease in suspended Cs concentration was more pronounced when anthropogenic activities in the watershed were more active, but there was no clear relationship between land use in the watershed and changes in river-bottom sediment Cs concentration. This indicates that suspended sediment Cs concentrations are controlled by initial deposition to suspended sediment production sources, whereas river-bottom Cs concentrations are controlled by multiple factors such as sediment traction and Cs supply from river water.

How to cite: Wada, N., Onda, Y., Gao, X., and Tang, C.: Changes in Cs-137 concentrations in river-bottom sediments and their factors in Fukushima Prefecture rivers, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11671, https://doi.org/10.5194/egusphere-egu23-11671, 2023.

EGU23-12670 | ECS | Orals | GI2.2

Minimizing the loss of radioactively contaminated sediment from the Niida watershed (Fukushima, Japan) through spatially targeted afforestation. 

Floris Abrams, Lieve Sweeck, Johan Camps, Grethell Castillo-Reyes, Bin Feng, Yuichi Onda, and Jos Van Orshoven

Government-led decontamination of agricultural land in the Fukushima accident (2011) region has lowered the on-site radiation risk considerably. From 2013 to early 2017, 11.9% of the land in the Fukushima disaster affected Niida watershed in Japan was remediated through topsoil removal. However, this resulted in a 237.1% increase in suspended sediment loads in the river for 2016 compared to 2013.  In contrast, sediment loads decreased by 41% from 2016 to 2017; this can be attributed to the effect of natural vegetation restoration on sediment yield and transfer patterns (Bin et al., 2022). Since radiocaesium firmly binds to the clay minerals in the soil, it is inevitably transported along with the sediments downstream to the river systems. These observations confirm that rapid, spatially targeted interventions, such as revegetation, e.g., through afforestation, have the potential to decrease the magnitude and period of increased exports of contaminated sediments. The CAMF tool (Cellular Automata-based Heuristic for Minimizing Flow) (Vanegas et al., 2012) was originally designed to find the cells in a raster representation of a watershed for which afforestation would lead to a maximal reduction of sediment exports with minimal effort or cost while taking sediment flow from cell to cell into account. In our research, we adapted the CAMF tool to account for the radiocaesium budgets associated with the transported sediments. We applied the approach to the Niida catchment, where land-cover changes in upstream decontaminated regions are detected using drone imagery and linked to increased sediment loads in the Niida river using long-term river monitoring systems. For example In 2014, agricultural land (18.02 km2) was one of the major land uses in the regions where decontamination was ordered, resulting in increased sediment loads from 2014 to 2016. By recognizing both the on- and off-site impacts of the remediation interventions and their temporal dynamics, the modified CAMF tool offers scope for supporting the formulation of spatio-temporal schemes for the remediation of agricultural land. These schemes aim to decrease the radiation risk for downstream communities and minimize the potential recontamination of already decontaminated sites.

How to cite: Abrams, F., Sweeck, L., Camps, J., Castillo-Reyes, G., Feng, B., Onda, Y., and Van Orshoven, J.: Minimizing the loss of radioactively contaminated sediment from the Niida watershed (Fukushima, Japan) through spatially targeted afforestation., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12670, https://doi.org/10.5194/egusphere-egu23-12670, 2023.

EGU23-13366 | Orals | GI2.2

Similarity of long-term temporal decrease in atmospheric Cs-137 between Chernobyl and Fukushima 

Kentaro Akasaki, Shu Mori, Eiichi Suetomi, and Yuko Hatano

We compare the atmospheric concentrations of Cs-137 after a decade between Chernobyl and Fukushima cases. We plotted 8 datasets on log-log axes (5 cases in Chernobyl and 3 cases Fukushima) and found that they appear to follow a single function.

There have been measured the atmospheric concentration after the Chernobyl accident for more than 30 years [1]. On the other hand, several teams of Japanese researchers have been measured in Fukushima and its vicinity for almost 10 years. [2][3] In this study, we compare 5 sites in Chernobyl (Pripyat, Chernobyl, Baryshevka, Kiev, and Polesskoe) and 3 sites in Fukushima (FDNPP O-6 and O-7, Univ. Fukushima).

We adjust the magnitude of the data because it depends on the amount of the initial deposition. After the adjustment, we plot the 8 cases on a log-log plot. We found that the 8 cases collapse together, with the power index of -1.6. Namely,

C(t) ~ t^{-1.6}.               …(1)

Incidentally, we have been proposed a formula which reproduce the long-term behavior of atmospheric concentration at a fixed location as

C(t) = A exp(-bt) t^{-4/3}    …(2)

where A is a parameter which relates to the amount of the initial deposition and b as the reaction rate of all the first-order reactions (including the radioactive decay rate, the vegetation uptake rate, the runoff rate, etc). We will investigate the difference in the power-law index in Eq. (1) and (2). The parameter b is highly dependent on the environment. When we take a proper value of b, the apparent decrease of the concentration will change from t^{-4/3}. We may make the apparent power-index close to -1.6.

 

[1] E. K. Garger, et al., J. Env. Radioact., 110 (2012) 53-58.

[2] A. Watanabe, et al., Atmos. Chem. Phys. 22 (2022) 675-692.

[3] T. Abe, K. Yoshimura, Y. Sanada, Aerosol and Air Quality Research, 21 (2021) 200636.

How to cite: Akasaki, K., Mori, S., Suetomi, E., and Hatano, Y.: Similarity of long-term temporal decrease in atmospheric Cs-137 between Chernobyl and Fukushima, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13366, https://doi.org/10.5194/egusphere-egu23-13366, 2023.

EGU23-13486 | ECS | Posters virtual | GI2.2

Distributions of tritium in the marine water and biota around Rokkasho Reprocessing Plant 

Satoru Ohtsuki, Yuhei Shirotani, and Hyoe Takata

For decommissioning of Fukushima Daiichi Nuclear Power Station (FDNPS), it is one of the biggest problems to treat the radioactive contaminated stagnant water in the building. It is difficult to remove H-3 from the contaminated water by only Advanced Liquid Processing System (ALPS) treatment. Thus, the Japanese Government announced to release the ALPS treated water containing H-3. To predict the alteration of the dose rate of the marine biota by the change of H-3 concentration in marine water after the release of ALPS water, it is necessary to understand the dynamics of H-3 in marine ecosystem. In this study, we studied the behavior of H-3 in the marine environment (water and biota) off Aomori and Iwate prefectures from FY2003 to FY2012, as the background data of the Pacific Ocean along the coast of the North East Japan. To clarify the dynamics of H-3 in marine biota, we compared H-3 and Cs-137. Excluding the period of the intermittent test operation of the Rokkasho Reprocessing Plant (FY2006-FY2008), the concentration of H-3 in seawater, tissue free water tritium (TFWT) and organically bound tritium (OBT) were 0.052-0.20 Bq/L with a mean of 0.12±0.031 Bq/L, 0.050-0.34 Bq/kg-wet with a mean of 1.1±0.039 Bq/kg-wet and 0.0070-0.099 Bq/kg-wet with a mean of 0.042±0.019 Bq/kg-wet, respectively. Before the FDNPS accident (FY2003-FY2010), Cs-137 concentration in seawater and marine biota were 0.00054-0.0027 Bq/L with a mean of 0.0016±0.00041 Bq/L and 0.022-1.8 Bq/kg-wet with a mean of 0.090±0.037 Bq/kg-wet, respectively. Concentration Ratio (CR), the ratio of the concentration of marine biota and seawater for TFWT, was to be 0.34-2.37 with a mean of 0.97±0.31 in all spices, meaning the concentration of marine biota was almost equal to seawater. For Cs-137, CR were 46-78 with a mean of 56±22. We compared CRs for TFWT of Gadus macrocephalus, Lophius litulon and Oncorhynchus keta with those of Cs-137. Comparing CR-TFWT and CR-Cs-137 for these three species, Spearman-R was <0.4 and p was >0.05, indicating that the dynamics of TFWT and Cs-137 in marine ecology is decoupled.

How to cite: Ohtsuki, S., Shirotani, Y., and Takata, H.: Distributions of tritium in the marine water and biota around Rokkasho Reprocessing Plant, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13486, https://doi.org/10.5194/egusphere-egu23-13486, 2023.

EGU23-15515 | Posters on site | GI2.2

137Cs transport flux to surface water due to shallow groundwater discharge from forest hillslope 

Yuma Niwano, Hiroaki Kato, Satoru Akaiwa, Donovan Anderson, Hikaru Iida, Miyu Nakanishi, Yuichi Onda, Hikaru Sato, and Tadafumi Niizato

Groundwater systems and surface water can interact in a complex manner that influences catchment discharge, which then becomes more complex in forest slopes. A large amount of Radioactive cesium (137Cs) deposited on forests due to the Fukushima Daiichi Nuclear Power Plant accident remains in terrestrial environments and is transported downstream as suspended or dissolved forms by surface water. Generally, the concentration of dissolved 137Cs in surface water increases especially during runoff. While the leaching behavior of 137Cs from contaminated forest materials and soils to surface water has been heavily studied, the influence of 137Cs concentration in shallow groundwater systems in forest slopes have not been investigated. Therefore, detailed hydrological observations of groundwater on a forest hillslope will enable quantitative analysis of the influence of groundwater flow on the formation of dissolved 137Cs concentrations in surface water during base flow and during runoff. Our results showed that the dissolved 137Cs concentration in surface water increases during water discharge. The average concentration of dissolved 137Cs in shallow groundwater was 0.64 Bq/L, which was higher than that in surface water (average 0.10 Bq/L). Furthermore, it was also observed that a part of the shallow groundwater on the slope moves toward the river channel at the time of water runoff. This suggests that shallow groundwater may have flowed into the surface water during the outflow and contributed to the increase of 137Cs in the surface water. In this study, the contribution of groundwater in forest slopes to the dissolved 137Cs concentration in surface water was estimated using the hydrodynamic gradient distribution of groundwater in forest slopes and the measured dissolved 137Cs concentration in groundwater.

How to cite: Niwano, Y., Kato, H., Akaiwa, S., Anderson, D., Iida, H., Nakanishi, M., Onda, Y., Sato, H., and Niizato, T.: 137Cs transport flux to surface water due to shallow groundwater discharge from forest hillslope, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15515, https://doi.org/10.5194/egusphere-egu23-15515, 2023.

EGU23-2006 | ECS | Orals | HS5.7

Soft-linking climate-land-water-energy assessment and planning models for sustainable development in rural Africa: preliminary results from the LEAP-RE RE4AFAGRI project 

Giacomo Falchetta, Muhammad Awais, Edward Byers, Vittorio Giordano, Gregory Ireland, Francesco Semeria, Marta Tuninetti, Adriano Vinca, and Ackim Zulu

In rural areas of Africa most communities live in poverty and lack access to services such as electricity and clean cooking fuels, water supply that is safe for human use, sufficient and nutritious food, crop irrigation systems, and appliances and services that can foster income generation. Promoting sustainable development requires an integrated understanding and planning along such dimensions. In the context of the RE4AFAGRI (“Renewables for African Agriculture”) project of  LEAP-RE (Long-Term  Joint  Research  and  Innovation  Partnership  on  Renewable  Energy between  the European Union and the African Union), four models representing land-water-crop-food-energy requirements and dynamics (WaterCROP, M-LED, OnSSET and MESSAGE-NEST) are calibrated and soft-linked. The ultimate aim is to enable a multi-scale, multi-sectoral assessment and planning of technologies and policies that can promote integrated sustainable development in the region. Here we present preliminary results for a set of scenarios in the country-study of Zambia. Results can inform both public decision-makers and private companies engaging in those sectors. The approach and open-source modelling platform are readily scaled and adapted to other countries and regions.

How to cite: Falchetta, G., Awais, M., Byers, E., Giordano, V., Ireland, G., Semeria, F., Tuninetti, M., Vinca, A., and Zulu, A.: Soft-linking climate-land-water-energy assessment and planning models for sustainable development in rural Africa: preliminary results from the LEAP-RE RE4AFAGRI project, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2006, https://doi.org/10.5194/egusphere-egu23-2006, 2023.

EGU23-3075 | Orals | HS5.7

Water-energy-food-ecosystem nexus governance: methodological aspects of the assessement of supportive and restrictive contexts 

Isabelle La Jeunesse, Caro E. Mooren, Stefania Munaretto, Frank Hüesker, Claudia Cirelli, Ingrid Canovas, Eva Sievers, and Kaoutar Mounir

Managing water resources in a sustainable way means, a fortiori in the context of increasingly visible climate change impacts, taking into account decisions made by other sectors having a significant effect on the availability and quality of water. Water quality and quantity are often affected by the energy sector on the one hand, and agriculture and food production on the other. Moreover, ecosystem requirements, such as minimum ecological flows or water quality, should always be considered. Thus, facing climate change impacts calls for increasing water-energy-food-ecosystems nexus considerations.

This being said, how can managers of these natural resources and stakeholders using them consider intersectoral coherence needs? Are these needs only theoretical or are they reflected by concrete actions in practice? Last but not least, how to assess the state of WEFE nexus governance in territories?

In order to address these questions, the present paper describes the methodological aspects of the WEFE nexus governance assessment tool (NXGAT) co-developed in the NEXOGENESIS project (H2020-funded). This tool assesses the state of the WEFE nexus governance in catchments. The goal of the NXGAT is to highlight what is actually supportive and what is actually restrictive to WEFE nexus governance.

The NXGAT is the first step in the WEFE nexus governance approach (Hüesker et al., 2022 ; Mooren et al., 2022) aiming at developing WEFE nexus policies. The NXGAT lays the foundation for cross-sectoral dialogue by both raising awareness and identifying solutions for more WEFE nexus governance.  The NXGAT assesses five dimensions (levels and scales; actors and networks; problem perspectives and goal ambitions; strategies and instruments; and responsibilities and resources) and five qualities (extent, coherence, flexibility, intensity of action, and fit) of the governance system. The tool is implemented in the Lielupe transboundary catchment (Lithuania-Latvia) by a team of transdisciplinary experts during face-to-face interviews. Interviewees are selected to cover the multi-scalar levels of all sectors.

The results of the implementation in the Lielupe transboundary catchment provide preliminary results on the efficiency of the method and the importance of the preparatory phases of the field investigation. The implementation of the NXGAT contributed to both underline blockages and leverages to urge for more intersectoral governance in this case study.

How to cite: La Jeunesse, I., Mooren, C. E., Munaretto, S., Hüesker, F., Cirelli, C., Canovas, I., Sievers, E., and Mounir, K.: Water-energy-food-ecosystem nexus governance: methodological aspects of the assessement of supportive and restrictive contexts, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3075, https://doi.org/10.5194/egusphere-egu23-3075, 2023.

Nexus research is advancing from knowledge creation towards public awareness and inclusiveness for civil society, public-private partnerships, and knowledge partners. Nexus research was mainly focused on a better understanding of interlinkages between the relevant resources at stake (e.g., water, energy, food, and ecosystems), the focus is increasingly searching for building communities, training, and career development. 

Research on the WEFE nexus increasingly aims to create platforms building capacity among institutions, knowledge partners, and capacity development. Educational and learning programs are developed by hot spots of the nexus. Expanding transdisciplinary research methods could facilitate building a community and network of nexus professionals. Capacity development and awareness are also critical for the successful planning and implementation of nexus practices. Some successful examples of knowledge creation for inclusiveness are shared.  The presentation will identify some key enablers and measures to advance the nexus in practice. Nexus research benefits from advancing along this route.

 

How to cite: Brouwer, F.: Nexus research for sustainability and inclusiveness in practice, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4370, https://doi.org/10.5194/egusphere-egu23-4370, 2023.

EGU23-5114 | Posters on site | HS5.7

Analysis of Transboundary Water-Food Nexus based on Physical-Virtual Water and Food Trade Network 

Sanghyun Lee, Makoto Taniguchi, Naoki Masuhara, Seung-Hwan Yoo, and Yun-Gyeong Oh

This study aimed to analyze the interaction among watershed, food-producing, and food-demanding areas through the connected system of physical-virtual water flows and local food networks in terms of the transboundary water-food nexus, even though they might not be geographically connected. Here, we analyzed the potential food network of local rice among 47 prefectures in Japan using the gravity model and estimated the physical-virtual water flows (PVWFs) by lining the physical water flow in food-producing areas and virtual water flow embedded in the food network. Through in-and out-degree centralities of the food network, we found that the results of degree centrality revealed which prefecture was more influenced by the changes in self-supply ratios (SSRs) of local rice. As all prefectures intended to increase consumption of local rice that was produced in their area, the scale of the food network was reduced, as shown by the decrease in in-and out-degree centralities. Based on the food network, we analyzed the dependency of food-demanding areas on each watershed based on a connected system of PVWFs. In a case study of the Kansai region, the northern watershed directly affected Hyogo, which was also indirectly influenced by Osaka in terms of PVWFs. In the food network with 20% SSR, the PVWF was estimated to be 189.17 x 106 m3·yr-1 from the northern watershed to Osaka in the food-producing area of the northern watershed, showing higher interaction of Osaka with the northern watershed than with other watersheds.

How to cite: Lee, S., Taniguchi, M., Masuhara, N., Yoo, S.-H., and Oh, Y.-G.: Analysis of Transboundary Water-Food Nexus based on Physical-Virtual Water and Food Trade Network, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5114, https://doi.org/10.5194/egusphere-egu23-5114, 2023.

EGU23-5826 | ECS | Orals | HS5.7

Systems Innovation Approach: stakeholders’ involvement for a climate resilient region, a Living Lab at the Main River basin 

Teresa Pérez Ciria, Raul Wood, Marion Zilker, Gunnar Braun, and Ralf Ludwig

Climate change poses major challenges globally and is likely to exacerbate competition for water, land, and energy resources. In the Main River Basin (Germany), this will have considerable consequences for agriculture, forestry, water, and energy management. At present, most adaptation measures are sector-focused, but the challenges are interconnected. The region is at risk for being pushed beyond its resilience threshold and therefore, a holistic and multi-sectoral strategy is urgently needed to achieve a new level of responsiveness to cope with climate change impacts.

The co-design and co-production of science-driven technical, social, and cross-sectoral innovations and governance is required to build new and climate resilient transformation pathways. A systemic transformation of the region requires time and broad societal support, which must be considered when formulating development paths. To address these challenges, Systems Innovation Approach (SIA) is implemented. This method aims at going beyond the immediate problems to better understand the underlying patterns, and how we can learn and adapt as the system continues to change. The Main River basin is one of the nine pilot areas of the EU funded ARSINOE project (Climate-resilient regions through systemic solutions and innovation) that are implementing innovative technological approaches. Stakeholders’ engagement is ensured through the so-called Living Labs. In the ARSINOE project, Living Labs are a participatory research tool often used in planning, product design and innovation which brings together a collective of key stakeholders to explore a focal issue. Living Labs act as open innovation spaces which foster co-creation with users and the focus is to better solve stakeholder needs.

Through a series of workshops supported by SIA tools (mental mapping of interconnected challenges, future common vision using Sustainable Development Goals (SDGs) as guiding principles, backcasting) we have created an open atmosphere with committed participants that are willing to collaborate to tackle future climate challenges in the Main River region. This contribution presents our successful experience turning research into practice, lessons learnt and challenges we faced to ensure the participants’ engagement.

The presented study is supported by the project ARSINOE (GA: 101037424), funded under EU’s Horizon 2020 research and innovation programme.

How to cite: Pérez Ciria, T., Wood, R., Zilker, M., Braun, G., and Ludwig, R.: Systems Innovation Approach: stakeholders’ involvement for a climate resilient region, a Living Lab at the Main River basin, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5826, https://doi.org/10.5194/egusphere-egu23-5826, 2023.

Measures that aim to reduce greenhouse gas emissions also have impacts on achieving other Sustainable Development Goals (SDGs). Given the enormous challenge of achieving the goals of the Paris Agreement and the SDGs, insight into these impacts provides information on how to improve feasibility of climate change mitigation measures by maximizing the co-benefits and managing the risks of possible trade-offs across SDGs. In this paper, we explore the impact of twenty promising climate mitigation measures on achieving the other SDGs for eleven world regions. Using the IMAGE modelling framework, the paper explores the GHG emissions reduction potential of these measures aggregated by sector under three scenarios. Based on peer-reviewed articles, the impact of the measures on other SDGs is assessed for the top three sectors with the highest GHG reduction potential in each region. We conclude that the number of synergies between the selected climate change mitigation measures and other SDGs dwarf the number of trade-offs in all regions. The magnitude of these synergies and trade-offs, however, varies by regional and socio-economic context. In high- and middle-income regions, the mitigation measures show few trade-offs that are generally associated with technology choices that could aggravate inequality and impact biodiversity. In low-income regions, some measures, especially land-use related ones, could interfere with efforts to reduce poverty, end hunger and improve well-being, if not complemented by additional policies that aim to protect the poor from increasing food and energy prices.

How to cite: Dagnachew, A. and Hof, A.: Climate change mitigation and SDGs: modelling the regional potential of promising mitigation measures and assessing their impact on other SDGs, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7411, https://doi.org/10.5194/egusphere-egu23-7411, 2023.

EGU23-7541 | ECS | Orals | HS5.7

Towards climate resilience: paving dynamic adaptation pathways for regional climate change hot-spots 

Dionysios Nikolopoulos, Iosif Spartalis, Christodoulos Pantazis, Nikos Pelekanos, Georgios Moraitis, Klio Monokrousou, and Christos Makropoulos

Climate change is one of the biggest challenges of recent times, with worldwide economic, societal, and environmental impacts. In response to these challenges, the European Union (EU) proposed the EU Green Deal which sets a blueprint that commits on transforming the EU into the first climate neutral continent by 2050. To this end, innovative solutions for climate-change adaptation and mitigation measures must be implemented in regional and local scales. The H2020 Green Deal project IMPETUS aims to develop and validate a coherent multi-scale, multi-level, cross-sectoral adaptation framework for climate change, paving the way towards a climate-neutral and sustainable future. This will be achieved by building on resilience knowledge and by co-designing together with local communities and stakeholders, innovative packages of methodological, technical, governance and financial solutions. Two such solutions developed within the project are a) the strategic resilience and multi-hazard management tool for identifying dynamic climate adaptation pathways and b) the climate change hot-spot identification and prioritization tool. Through a co-creation approach, stakeholders identify region-specific indicators and metrics of interest that describe climate risk exposure, vulnerability, and adaptation capacity. The hot-spot analysis based on these metrics utilizes collections of spatiotemporal datasets, including future climate scenarios and projections, that describe key parameters from the human and climate dimensions, able to identify hot-spots associated with different climatic and socioeconomic futures. The hot-spot explorer tool is an EU-wide web service and can be used as a screening tool for policymakers to prioritize regions for development of regional adaptations pathways, using the dynamic adaptation pathways tool. A regionally suitable pallet of intervention measures is identified from stakeholder engagement. The pallet is stress-tested for assessing regional climate resilience, under a multitude of different future scenarios, with the objective to generate pathways of progressive implementations of intervention packages that improve the specified indicators and metrics. Some of the intervention options are also operationalized in pilot case studies within the project, such as the employment of sewer mining units in the wastewater system of East Attica for water reuse. The pathways are dynamic and adaptative to changing future conditions, as there are a) key monitored parameters for a region with alarms associated to decision points involving intervention measure implementations, and b) a contingency response module that supports stakeholders to select interventions from different pathways. These tools engage policymakers and stakeholders in order to identify climate change hot-spots within EU, prioritize them, identify suitable intervention measures, and analyze their regions to generate strategic plans for adaptation pathways towards the common climate resilience goal.

Acknowledgement

This work is supported by IMPETUS research project, which received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement  No. 101037084.

How to cite: Nikolopoulos, D., Spartalis, I., Pantazis, C., Pelekanos, N., Moraitis, G., Monokrousou, K., and Makropoulos, C.: Towards climate resilience: paving dynamic adaptation pathways for regional climate change hot-spots, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7541, https://doi.org/10.5194/egusphere-egu23-7541, 2023.

EGU23-9994 | ECS | Orals | HS5.7

Bringing knowledge closer to practice: an inferential analysis of EU climate change policies and measures 

Nikos Pelekanos, Dionysios Nikolopoulos, Georgios Moraitis, and Christos Makropoulos

In the context of climate change, European Member States are committed to developing policies and taking corresponding adaptation measures. In this direction, every two years, the European Environment Agency (EEA) publishes an extensive dataset related to climate policies and measures (PaMs) reported in Europe and generated by European research projects, with the aim of improving and disseminating the information covering all actions aimed at reducing GHG emissions. In this study, an inferential data analysis is conducted on the PaMs dataset, setting as the variable of interest the reported quantified GHG emissions savings of each PaM and inferring its variance through a set of related explanatory qualitative factors (i.e., type of measure, sector of policy, related entities, implementation period etc.) together with their higher-level interactions. This is achieved by employing a number of widely used statistical techniques for the analysis of multi-factor data, such as regression analysis, hypothesis testing, influence diagnostics and variable selection methods to (a) investigate the significance and effect of the factors in relation to GHG emissions and (b) model the relationships between the variables of interest. The resulting analysis aims to obtain practical insights from a retrospective view of a wide number of PaMs and generalize their response in a descriptive and explicable way. This will allow the interested parties to gain interpretable feedback from existing measures applied in practice and subsequently ‘feed back’ new knowledge on climate adaptation decision making.

This work is supported by IMPETUS research project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 101037084.

How to cite: Pelekanos, N., Nikolopoulos, D., Moraitis, G., and Makropoulos, C.: Bringing knowledge closer to practice: an inferential analysis of EU climate change policies and measures, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9994, https://doi.org/10.5194/egusphere-egu23-9994, 2023.

EGU23-10472 | ECS | Posters virtual | HS5.7

Scenario discovery with an integrated assessment model to identify robust, policy-relevant scenarios for capacity expansion in Latin America 

Jacob Wessel, Jonathan Lamontagne, Gokul Iyer, and Thomas Wild

The ongoing global transition to a deeply decarbonized electricity system represents a complex problem. Deep uncertainty in the future pathways of power system capacity expansion and interactions across sectors has led stakeholders to seek out robust methods capable of informing multi-scale, multi-sector tradeoffs among policy pathways within the energy-water-food nexus. In this study, scenario discovery is applied to a large scenario ensemble generated using a global-scale integrated assessment model with a regional focus on Latin America. Scenario discovery is a powerful method for identifying robust, policy-relevant scenarios from large, many-dimensional ensembles of model realizations. Here, ten uncertain sensitivity factors consistent with previous analyses are varied within the model configuration, representing technological costs and efficiencies, advanced electrification, institutional factors, and national climate pledges, among others. The resulting scenario ensemble maps out the impacts of a combinatorial time-evolving uncertainty space defined by these sensitivity factors, using generation mix, electricity cost, energy burden, and energy intensity as power system performance metrics. Additional metrics are utilized to explore cross-sectoral implications of scenarios. The scenario discovery analysis identifies the key global drivers of regional outcomes in Latin America, as well as tradeoffs and synergies regarding climate change mitigation and the future evolution of the Latin American electric power system. Our results underscore the importance of considering coupled systems and the advantages of large-scale scenario ensembles in capacity expansion analyses.

How to cite: Wessel, J., Lamontagne, J., Iyer, G., and Wild, T.: Scenario discovery with an integrated assessment model to identify robust, policy-relevant scenarios for capacity expansion in Latin America, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10472, https://doi.org/10.5194/egusphere-egu23-10472, 2023.

EGU23-11101 | ECS | Orals | HS5.7

Supply and demand assessment and mismatch analysis of ecosystem services to support sustainable land management 

Jiwon Kim, Mina Hong, Sol-E Choi, Cholho Song, Chul-Hee Lim, Yun Eui Choi, and Woo-Kyun Lee

Due to the land degradation, the land use conflicts have intensified, and there is an increasing necessity to adapt sustainable land management. Sustainable land management deals with the demands for land in terms of not only human society but also the nature conservation and biodiversity. To persue and realize sustainable land management, the indicators and evaluation system are necessary, and ecosystem services has emerged as the proper indicator for sustainable land management. This study focused on the balance between the demand and supply of ecosystem services. If the balance between them was maintained or supply exceeded demand, the land can be assessed to be managed sustainably. In this study, CO2 sequestration, Heat mitigation, and water provision were assessed as ecosystem service in South Korea. The supply of each ecosystem service was evaluated by using related models which had been developed and used widely in previous studies. The demand of each ecosystem service was defined based on specific figures which had already suggested as policy goals in South Kroea in purpose of drawing social consensus. Afterwards, the ecosystem services supply and demand ratio (ESDR) were calculated to show the balance between supply and demand quantified by region. As a result, the exessive demand for CO2 sequestration service was found compared to supply. The supply of heat mitigation service was found to be sufficient for the demand nationwide. However, in specific areas such as cities, the demand was higher than the supply. In the case of water provision service, the national demand was being met by some regional suppliers. Through these results, it is possible to find out the ecosystem services that need to be supplemented spatially and regionally, and ultimately, it is expected to support the establishment of urban space, green space, and environmental planning at the regional and national levels.

How to cite: Kim, J., Hong, M., Choi, S.-E., Song, C., Lim, C.-H., Choi, Y. E., and Lee, W.-K.: Supply and demand assessment and mismatch analysis of ecosystem services to support sustainable land management, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11101, https://doi.org/10.5194/egusphere-egu23-11101, 2023.

EGU23-12105 | Orals | HS5.7

A probabilistic framework to assess resilience in regional water systems - exploring the impact of circular water strategies 

Dimitrios Bouziotas, Dionysios Nikolopoulos, Panagiotis Dimas, Jos Frijns, and Christos Makropoulos

Contrary to the ‘make-use-dispose’ linearity seen in conventional resource management, circular economy design principles have been proposed as an  alternative that reduces waste and promotes efficiency. These principles find use in water as well, offering an alternative against centralized water systems planning and management. Despite the intrinsic links between circularity and resilience, few studies have advanced the identification and discussion of linkage beyond a theoretical or conceptual level. Moreover, few studies have estimated resilience with a probabilistic approach to include the inherent future uncertainty located simultaneously at source and demand level. In this study, a probabilistic framework to assess resilience for regional systems across multiple domains (drinking water, wastewater and drainage) is presented. The framework is based on stress-testing using an urban water cycle model, paired with reliability-based Key Performance Indicators (KPIs) that describe system resilience for each domain and for several different stress-testing factors (stressors). For its practical implementation, the framework is then applied to the provincial case study of Delfland, the Netherlands, where different circular water strategies are evaluated in terms of their overall resilience, (a.) firstly deterministically to explore the impact of individual stressors, and (b.) probabilistically to evaluate system performance against future uncertainty. The results quantitatively demonstrate that circular water options lead to water systems of increased resilience. The more circular dimensions are addressed through interventions and management strategies, the more robust resilience profiles become across different urban water cycle domains, thus securing regional water systems against future uncertainty.

How to cite: Bouziotas, D., Nikolopoulos, D., Dimas, P., Frijns, J., and Makropoulos, C.: A probabilistic framework to assess resilience in regional water systems - exploring the impact of circular water strategies, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12105, https://doi.org/10.5194/egusphere-egu23-12105, 2023.

EGU23-12166 | ECS | Posters on site | HS5.7

Enabling far-reaching living labs through regional Digital Twins 

Georgios Moraitis, Christodoulos Fragkoudakis, Spyridon Tsattalios, Dionysios Nikolopoulos, Nikos Pelekanos, Klio Monokrousou, and Christos Makropoulos

The current and future landscape of our societies is predominantly governed by urgent (and interconnected) resilience challenges such as climate change adaptation, resource efficiency and sustainable WEFE nexus management. To overcome those challenges, the European Union (EU) has set the blueprints of transformational changes with the European Green Deal, that builds on research and innovation to meet the objectives. Despite advances in the field, the uptake pace of relevant innovations is often hindered by the narrow communication paths among research, public administration and citizens -who are the end beneficiaries. This work utilizes the capabilities of Digital Twins (DT) to connect hard and soft sensors with environmental and infrastructure models at regional scale, to create a central hub for related data and knowledge to be turned into action in a co-creation process. By building on existing data driven platform initiatives by the Ministry of Environment and Energy and the Decentralized Administration of Attica, we build the DT of the Region of Attica to provide: (i) access to relevant datasets (environmental, climatic, uses of resources etc.), (ii) access to relevant climate adaptation services (e.g. climate services, services to farmers, services to municipalities), (iii) links to local and regional Communities of Practice (CoP) and (iv) a repository for demonstrations of climate adaptation innovations within the region. This knowledge collaboration scheme forms a living lab constellation that allows rapid and far-reaching sharing, accumulation, transformation, and co-creation of knowledge among the administration parties and local case studies’ stakeholders. Like ancient sailors who used constellations to navigate along route, our modern societies can use the living lab constellations of the regional DT to chart evidence-based pathways towards climate resilience and sustainable WEFE management. This dynamic and expandable ecosystem aims to speed up the introduction of climate adaptation innovations, connect knowledge and bring research closer to practice by allowing for a re-wiring of culture, where science and co-creation are perceived as necessary for successful policy making. 

Acknowledgment: This work is supported by IMPETUS research project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 101037084.

How to cite: Moraitis, G., Fragkoudakis, C., Tsattalios, S., Nikolopoulos, D., Pelekanos, N., Monokrousou, K., and Makropoulos, C.: Enabling far-reaching living labs through regional Digital Twins, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12166, https://doi.org/10.5194/egusphere-egu23-12166, 2023.

EGU23-12376 | Orals | HS5.7

On building a general framework for assessing food security risk under probabilistic socioeconomic scenarios 

Georgios Papayiannis, Phoebe Koundouri, Achilleas Vassilopoulos, and Athanasios Yannacopoulos

Food security is a key issue in sustainability studies. In this work, a general framework for providing detailed probabilistic socioeconomic scenarios as well as predictions concerning food security is proposed. Our methodology builds (a) on the Bayesian probabilistic version of world population prediction model and (b) on the dependencies of food needs and food system capacities on key drivers, such as population, gross domestic product (GDP) and other socioeconomic and climate indicators. In this perspective, the concept of the recently developed convex risk measures involving model uncertainty is employed for the construction of a risk assessment framework in the context of food security. The proposed method provides within and across the various probabilistic scenarios predictions and evaluations for food security risk. Our methodology is illustrated by studying food security and quantifying the occurring risk in Egypt and Ethiopia up to the year 2050, in the combined context of the Shared Socioeconomic Pathways (SSPs) and the Representative Concentration Pathways (RCPs).

How to cite: Papayiannis, G., Koundouri, P., Vassilopoulos, A., and Yannacopoulos, A.: On building a general framework for assessing food security risk under probabilistic socioeconomic scenarios, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12376, https://doi.org/10.5194/egusphere-egu23-12376, 2023.

EGU23-12746 | ECS | Posters virtual | HS5.7

Water-Energy-Food nexus in Algeria; Ain Temouchent case study 

Leila Mostefaoui

Given the complexity of the interactions between water, energy, and food, any alteration to one sector can have impacts on the other sectors of the system.(Sušnik et al., 2018).Scientists are increasingly recognizing the need for an integrative approach to planning and managing resources. Hoff explained that several factors have influenced the demand for water, energy, and food, and listed the following; population growth, sustainable development, climate change, degradation, and scarcity of resources.(Hoff & Ulrich, 2017)

Algeria is ranked 1st among the Arab countries which have exceeded two-thirds of the way to achieving the SDGs (Dahan et al., 2019.), but according to Hoff (Hoff & Ulrich, 2017), the countries in the MENA region have not made remarkable progress in adopting the nexus approach due to several constraints such as lack of experience and insufficient management planning. ((Hoff & Ulrich, 2017).  As part of establishing the nexus approach in Algeria, we have selected the region of Ain Temouchent as a case study known for its agricultural vocation.

Ain Temouchent is located on located in the northwestern of Algeria, 520 km from the capital Algiers, and a hundred kilometers from the border Moroccan. And limited: to the North, by the Mediterranean Sea, to the South West, by Tlemcen, to the South East, Sidi Bel Abbes, and, to the east, by Oran. The region area is about 2,376 km² with a façade sea of 84 km and the population is over 406,000. The agricultural sector represents 15.22%, and the construction sector employs 14.19% of the employed population. The region of Ain-Temouchent is characterized by a Mediterranean climate with a hot summer and a temperate winter. The intensification of agricultural production in this region has led to the overexploitation of groundwater resources, and the establishment of a combined cycle thermal power station has accentuated its path towards a more considerable development, following its satisfaction in electrical energy. The establishment of a reverse osmosis desalination plant (Benisaf Water Company) with a production capacity of 200,000m3/day significantly alleviated the crisis situation, but its energy consumption and environmental impact raise several questions

Considering all these segments, one of the objectives of the study is to determine the key links between segments of the Nexus and understand the dynamics between them using System Dynamics Modeling. ((Aliyev et al., 2019))

This work aims to determine the links between water, food, and energy and to analyze the dynamics between them, also to propose solutions and recommendations for developing effective policies for the region.

 

How to cite: Mostefaoui, L.: Water-Energy-Food nexus in Algeria; Ain Temouchent case study, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12746, https://doi.org/10.5194/egusphere-egu23-12746, 2023.

EGU23-12902 | Orals | HS5.7

Experiences from storm surge flood damage modelling driven by local decision makers 

Martin Drews, Kirsten Halsnæs, Per Skougaard Kaspersen, and Bodil Ankjær Nielsen

A large part of the current research on flood damage costs build on a similar methodological framework across studies that integrates climate data (hazard), flood modelling (exposure), damage cost assessments (impact) and calculate risks as the product of the likelihood of events and their consequences. A key question here is how relevant such a methodological framework is in relation to the perspectives of decision makers on establishing safe standards for investments in climate change adaptation in the context of the large uncertainties surrounding both estimates of the extreme event probability and on the damages of these. Particular issues that are often raised by decision makers are related to how extreme precipitation and storm surge levels could be, and on how well the damages of such events are represented in damage estimates recognizing the limitations of monetary evaluations as well as risk preferences of decision makers.

The paper is addressing how the gap between conventional approaches applied to hazard and impact modelling and the needs and practice of decision makers can be diminished based on the experiences with the development and application of a detailed object based spatial DamageCost Model for storm surges. The model has been widely applied by Danish local governments as a basis for developing adaptation plans. Soon after the first version of the model was released, local Danish governments took over leading the model development from a user perspective in a close ongoing dialogue with DTU and the engineering consultants LNH Water, which through several projects, including the EU ARSINOE project continue to support further technical development and model use.

Experiences from how the model development have been inspired by decision maker perspectives gained through model use are reported based on case studies for the Danish cities of Esbjerg, Odense, and Aabenraa.

How to cite: Drews, M., Halsnæs, K., Skougaard Kaspersen, P., and Ankjær Nielsen, B.: Experiences from storm surge flood damage modelling driven by local decision makers, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12902, https://doi.org/10.5194/egusphere-egu23-12902, 2023.

EGU23-13100 | ECS | Orals | HS5.7

Enhancing the resilience of intermittent water supply systems in Khan Younis, Gaza Strip. Knowledge transfer and lessons learned from the Gaza H2.0 project 

Andrea Cominola, Ivo Daniel, David Tilcher, Ahmed J. S. Alasmar, Rami M. M. Ziara, and Giovanni Pedron

Future water security in Palestine is challenged by the compound effect of water scarcity, operational inefficiencies in water supply infrastructure, and the unstable geo-political setting. Among these factors, water losses represent a major challenge to the environmental sustainability and financial stability of water resources management in the area. The Palestinian Water Authority estimated the amount of non-revenue water (NRW) in the Gaza Strip to approximately 35.7 million cubic meters in 2018. This is equivalent to a direct loss of 37.6% of the total water supplied, further indirectly implying inefficient use of water-related energy and resources to treat and distribute water.

Water loss reduction and more sustainable water supply are key priorities in Khan Younis, the second most populated city in the Gaza Strip. Water supply and sanitation services in Khan Younis are managed by the Khan Younis Municipality (KYM). The KYM water distribution system is currently operated with an intermittent water supply scheme based on empirical and expert-based knowledge. The water loss rate in Khan Younis is rather uncertain and different estimates exist. However, the average water consumption from data provided by KYM in early 2021 was estimated to 74.7 liters per capita per day (lcd), which resides in the range recommended by the World Health Organization to meet the basic water needs, while the daily amount of water supplied via the distribution network was on average 99.5 lcd, indicating a NRW rate of approximately 25%.

In this work, we discuss lessons learned from the ongoing EU funded project “Gaza H2.0: Innovation and water efficiency” which aims at promoting efficient and sustainable water supply and demand, along with knowledge transfer to enhance resilience against water scarcity in the Gaza Strip. First, we analyse the gaps between research and practice which emerged in the project while updating the hydraulic model of the KYM water distribution. A rich body of literature highlights that building and calibrating a hydraulic model of a water distribution network is not a straightforward task that depends greatly on available data, calibration techniques, and modeler’s expertise. This was proven true for building the KYM water distribution network model, as an up-to-date inventory of network components was not available and only limited historical data were recorded. Thus, an extensive surveying campaign was run in 2021 via the installation of 51 pressure sensors logging data with a 1-min frequency throughout the 27 distribution zones in the network. As a result, sufficient measurement data was recorded to perform an initial calibration of the hydraulic model. However, some components of the network remain ungauged. We will thus discuss lesson learned and propose recommendations to enhance hydraulic model calibration for KYM and similar networks. Second, we will describe and discuss the strategies planned and invoked during the Gaza H2.0 project to foster knowledge transfer to and increase involvement from all stakeholders. These actions aim to guarantee the long-term sustainability of the technological solutions proposed in the project, such that they can serve as a starting point to address future climate and infrastructure challenges.    

How to cite: Cominola, A., Daniel, I., Tilcher, D., Alasmar, A. J. S., Ziara, R. M. M., and Pedron, G.: Enhancing the resilience of intermittent water supply systems in Khan Younis, Gaza Strip. Knowledge transfer and lessons learned from the Gaza H2.0 project, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13100, https://doi.org/10.5194/egusphere-egu23-13100, 2023.

EGU23-13219 | Orals | HS5.7

Opportunities and Challenges in the Efficient Exploiting of Land, Energy and Water Resources within the Volta and Tana Basins in Africa 

Frank Ohene Annor, Viktoria Martin, Eric Antwi Ofosu, Carlos Guerrero Lucendo, Boniface Akuku, Rafatou Fofana, Nick van de Giesen, and Edo Abraham

The design of strategic investments in water, energy and food (WEF) infrastructures is challenging because the size, location, technology mix and pace of development is made uncertain by multiple factors. For example, the return on investment, which comes long after building a hydropower dam, is made uncertain by local, regional and global climate and socio-economic factors. This is exacerbated by the challenges associated with the impacts of climate change, especially in sub-Saharan Africa (SSA) where it is difficult to model these impacts, hence leading to high levels of uncertainty in future scenarios (2050 and beyond).

Long-term investment planning and system operations for energy, depend on and compete with other sectors for, the availability of water (for hydropower and cooling thermal plants) and land resources (e.g. for biofuel production and arability). The efficient exploitation of land, energy and water resources and their synergised use for economic development therefore require an multidimensional integrated optimisation approach co-created with stakeholders in dialogue. This starts with planning followed by prioritised investments based on local, national and regional needs in the energy, agricultural and water sectors. This is mostly lacking in SSA at the moment. We gathered a selected group of experts in Accra, Ghana in November 2022 with a broad mix of experiences and expertise in the energy, water and agricultural sectors, who shared deeper insights and values of the need for integrated WEF planning to begin tackling challenges and opportunities identified in the Volta Basin in West Africa (starting with Ghana) and the Tana basin in Kenya. The main challenge identified was the disjointed planning of WEF infrastructures due to different financing mechanisms and siloed sectoral thinking; and participants raised emerging opportunities for planning infrastructure through transnational and regional cooperation  as well as the need to build on existing and new initiatives devoid of entrenched political goals.

In this contribution, we will present some of the main findings from the meeting in Accra and share knowledge on how transparent WEF modelling can be contextualised for local operational relevance, and through co-creation, how interactive engagement tools can be used for planning, policy- and decision-making.

Keywords: WEF modelling, sub-Saharan Africa, WEF Infrastructures, Investment Planning, Optimisation

The work leading to these results has received funding from the European Horizon Europe Programme (2021-2027) under grant agreement No.101083763 (EPIC Africa). The opinions expressed in the document are of the authors only and in no way reflect the European Commission’s opinions. The European Union is not liable for any use that may be made of the information.

How to cite: Annor, F. O., Martin, V., Ofosu, E. A., Lucendo, C. G., Akuku, B., Fofana, R., van de Giesen, N., and Abraham, E.: Opportunities and Challenges in the Efficient Exploiting of Land, Energy and Water Resources within the Volta and Tana Basins in Africa, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13219, https://doi.org/10.5194/egusphere-egu23-13219, 2023.

EGU23-14318 | ECS | Orals | HS5.7

Investigating the potential role of pumped hydro storage in the Ethiopian energy system transitions to 2050 using OSeMOSYS 

David de Vries, Jagruti Ramsing Thakur, Viktoria Martin, Frank Annor, and Edo Abraham

Ethiopia’s energy demand is expected to increase sevenfold in the coming 30 years, resulting in increased variable renewable electricity (VRE) production by solar PV and wind. Energy storage acts as a buffer that mitigates the effects of over- or under-capacity in production by VRE. With 97% of global bulk energy storage, pumped hydro storage is the most widely used and mature energy storage technology. With its long operational life, high round-trip efficiency (80%) and stable cost trajectory, it is a competitive option for many VRE-rich (future) energy systems. However, barriers to pumped storage include heavy technical, site-specific restrictions, long construction times and high initial capital investment requirements.

This study investigates if Ethiopia’s energy pathways benefit from adding pumped hydro storage, suitable regions for PHS, and to what extent storage would increase system resilience. The long-term energy planning tool OSeMOSYS is used, which allows for detailed investigation into system dynamics whilst parallelly minimising costs. OSeMOSYS enabled the investigation into Ethiopia by looking at an extensive host of techno-economic specifications and supply and demand dynamics from the electrification of transport and integration of variable renewables to residential cooking demands.

This research studies thirteen scenarios which are separated into three main categories: Base Case (3), Emission Penalty (EMI) (6) and Varying Wind Capacity and Seasonality (WND) (6). The base case introduces pumped storage to the energy pathways, and the EMI scenario characterises three pathways for carbon pricing. In the WND scenario, wind power’s capacity factor and seasonality are altered to investigate the potential effects of using more accurate local data or prioritising some supply zones on the energy system configuration. Additionally, the most favourable locations for solar PV and wind are combined with potential PHS locations to find optimal sites for storage construction.

The results of the research show that pumped hydro storage is adopted into the energy system in all scenarios, following both a diurnal and seasonal (dis)charge pattern. Variable renewable integration increases by an average of 10% from the addition of storage (78 GWh). The emission penalty increases the electrification of residential cooking demand and boosts VRE penetration but does not integrate storage integration further than the base case due to reaching the upper limit of the storage capacity set in the planning experiments.

Pumped hydro storage was found to increase the resilience of the modelled energy systems to climate-driven seasonal uncertainties and prices due to fossil fuel and carbon price uncertainties by making them less dependent on fossil fuels, decreasing vulnerability for potential emission penalties, and seasonal capacity fluctuations. The introduction of PHS was also found not to increase overall system costs, making it, combined with the stable levelised cost of storage and high maturity, a prime candidate for large-scale energy storage in Ethiopia.

How to cite: de Vries, D., Ramsing Thakur, J., Martin, V., Annor, F., and Abraham, E.: Investigating the potential role of pumped hydro storage in the Ethiopian energy system transitions to 2050 using OSeMOSYS, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14318, https://doi.org/10.5194/egusphere-egu23-14318, 2023.

EGU23-15624 | ECS | Posters on site | HS5.7 | Highlight

How effectively (or not) can science and research be turned into adopted solutions and policies? 

Elena Matta, Andrea Cominola, Chrysi Laspidou, Aitor Corchero Rodriguez, Marco Micotti, Manuel Pulido Velázquez, Matteo Giuliani, and Andrea Castelletti

How to create an impact on policies, operations, and society across the interdisciplinary sectors in which we - as researchers - are involved? Managing the Water-Energy-Food-Ecosystem (WEFE) nexus and pursuing climate resilience is the core task of several European (EU) projects and is in the highest interests of our society. The European Commission’s research funding programs attempt to address a large range of topics and offer unique opportunities for scientists to create a tangible impact on the environment and society.

We are currently involved in different EU projects, including AWESOME (PRIMA), which aims at managing the WEFE nexus across sectors and scales in the South Mediterranean exploring innovative technologies such as soilless agriculture in the Nile Delta; CLINT (H2020), which is developing Machine Learning (ML) techniques to improve climate science in the detection, causation, and attribution of extreme events to advance climate services; IMPETUS (H2020), whose efforts are dedicated on the elaboration of climate data space enhanced with ML algorithms to support the elaboration of climate policies; REACT4MED (PRIMA), which focuses on combating land degradation and desertification by improving sustainable land and water management through the identification of local good restoration practices and their potential upscaling; Gaza H2.0: Innovation and water efficiency (EuropeAid), which aims at promoting efficient and sustainable water supply and demand as well as knowledge transfer to enhance resilience against water scarcity in Gaza; GoNEXUS (H2020), which is developing an evaluation framework to design and assess innovative solutions for an efficient and sustainable coordinated governance of the WEFE nexus; NexusNet (COST), which creates the network and the community of WEF nexus advocates for a low-carbon economy in Europe and beyond; NEXOGENESIS (H2020), which focuses on streamlining water-related policies with artificial intelligence and reinforcement learning; MAGO (PRIMA), which builds web applications for water and agriculture in the Mediterranean; BIONEXT (HEU), which is interlinked with the Intergovernmental Panel on Biodiversity and Ecosystem Services and aims at creating transformative change through nexus analysis.

Despite the efforts of the scientific community, there is still a gap between research and practice. Researchers face difficulties in engaging stakeholders and decision-makers to jointly explore and shape the developed solutions, as well as to truly adopt them. The large-scale implementation of suitable technological solutions might require time and financial resources beyond the project’s lifetime and capacity. The lack of follow-ups and collaboration among projects with similar aims can be some of the reasons lying behind. Also, the complexity of finding open data in data-scarce regions makes results less trustable in the eyes of international agencies, while the pressure of publishing often turns research tasks into pure academic exercises. To what extent does the European strategy work? Is it only gaining scientific advances or also leading to local policy changes? Engaging important local actors (e.g., ministries), small-medium enterprises and societal members in the project consortia, empowering scientists by ensuring feedback loops with local governmental agencies, including the human dimension into modelling, and running effective capacity-building campaigns can be some food for thoughts to shape new strategies.

How to cite: Matta, E., Cominola, A., Laspidou, C., Corchero Rodriguez, A., Micotti, M., Pulido Velázquez, M., Giuliani, M., and Castelletti, A.: How effectively (or not) can science and research be turned into adopted solutions and policies?, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15624, https://doi.org/10.5194/egusphere-egu23-15624, 2023.

EGU23-15642 | ECS | Posters on site | HS5.7

Developing policy recommendations to support innovation in soilless agriculture within the Nile River Basin: A participatory approach using Multi-Actor Working Groups 

Lydia Stergiopoulou, Ebun Akinsete, Nouran El-Said, and Phoebe Koundouri

Increasing demand for energy, food and water in the Mediterranean along with the decline of freshwater availability due to climate change necessitate the exploration of options for producing more food with less water, land and energy. Innovations in soilless agriculture aim to address this challenge by exploring novel approaches towards food production including aquaponics and hydroponics. However, inadequate and inefficient legislation and policy frameworks are ill equipped to provide the support necessary for the successful uptake and scale out of these new technologies.  This paper examines the implementation of soilless technologies in the water-stressed Nile River Basin. By applying a stakeholder-centered participatory approach developed by the project which takes into consideration the Water-Energy-Food- Ecosystem (WEFE) Nexus, we present targeted policy recommendations for the development of soilless agriculture in the region which inherently embed the views of key local stakeholders. 

How to cite: Stergiopoulou, L., Akinsete, E., El-Said, N., and Koundouri, P.: Developing policy recommendations to support innovation in soilless agriculture within the Nile River Basin: A participatory approach using Multi-Actor Working Groups, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15642, https://doi.org/10.5194/egusphere-egu23-15642, 2023.

EGU23-15664 | ECS | Posters on site | HS5.7

Establishment of Rural Living Area Boundary for Sustainable Agri-Food System 

Jeongwoo Han, Kihwan Song, and Jinhyung Chon

In general, rural areas are declining due to urbanization and climate change, which affects the agri-food system centered on rural residents. For agri-food systems, the size and connectivity of regional systems are important, and the boundaries of people living in rural areas must be clearly defined. To effectively respond to these problems, the Republic of Korea proposed a policy plan for rural areas. However, there are issues with this approach since it is based on a legal spatial unit—meaning rural residents are not receiving the full breadth of intended benefits. It is necessary to readjust the spatial boundaries by aligning them more closely with the extent of the rural residents' living radius and the standards for services. This study aimed to establish the concept of a living area as it relates to rural areas, present criteria for setting the range and dimensions of a living area, and to then apply it to case studies. The target area was Muju-gun, Korea. It contains rural areas that face various problems such as population decline and aging. First, the concept of the rural living area was established based on insights gained from relevant literature reviews. The rural living area concept was defined as “a unit or range of spaces where rural residents can receive services to live and to support economic activities.” Second, building on the concept of the rural living area, the Muju-gun population, living service facilities, road networks, and watershed items were established, while relevant maps were collected. These materials were leveraged to conduct a network analysis. The closest facility analysis was performed and a network map was developed by overlaying the population and living service facilities with 12 key sectors (childcare, education, welfare, culture, physical education, health, medical care, commerce, finance, administration, transportation, and rest) and using the road network connecting them. Third, the range of living zones classified in order of size (small/medium/large) and by key sector in Muju-gun was derived. Excluding any missing values, a total of 30 Muju-gun living area ranges were drawn and presented. It was asserted that this was due to the fact that life service facilities in Muju-gun vary based on sector and size. The results of this study are particularly meaningful in that they presented a range based on the information that rural residents live in reality, and not an administrative district superimposed by the Republic of Korea—which reflects the existing legal standard unit. Since the derived range was based on the actual living range of rural residents, we expect efficient policy utilization in the planning and management of the agri-food system.

This work was carried out with the support of “Cooperative Research Program for Agriculture Science and Technology Development(Project No. PJ0171102022)” Rural Development Administration, Republic of Korea.

How to cite: Han, J., Song, K., and Chon, J.: Establishment of Rural Living Area Boundary for Sustainable Agri-Food System, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15664, https://doi.org/10.5194/egusphere-egu23-15664, 2023.

EGU23-16116 | Orals | HS5.7

AquaPlan: Bridging the gap between research and practice in crop-water modeling 

Timothy Foster, Thomas Kelly, Ryan Avery, and Kathryn Berger

Crop-water simulation models are powerful tools to support efficient and sustainable agricultural water use and management globally. However, uptake of these tools beyond the research community in policy and industry has traditionally been constrained by the complexity and closed-source nature of model codes, which limit ability for models to be adapted and applied to address complex real-world agricultural water management challenges. In this talk, we present AquaPlan, an interactive web-based tool crop management tool that enables farmers, businesses, and governments to make more informed decisions about water management, irrigation investments, and climate risks. AquaPlan combines a state-of-the-art open-source crop-water model, AquaCrop-OSPy, with global weather and soil datasets to enable users to conduct rapid on-the-fly assessments of field and regional-scale crop yield and water demands anywhere in the world. The tools also integrates future climate projections from CMIP6 models, providing insights to support efforts to enhance long-term resilience of agriculture and food supply chains to climate change. In this talk, we will present a range of use cases of AquaPlan, highlight how these kinds of interactive tools can strengthen uptake of models developed by researchers in water management policy, practice, and business.

How to cite: Foster, T., Kelly, T., Avery, R., and Berger, K.: AquaPlan: Bridging the gap between research and practice in crop-water modeling, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16116, https://doi.org/10.5194/egusphere-egu23-16116, 2023.

EGU23-16319 | ECS | Orals | HS5.7 | Highlight

Political instability influence on hydropower planning in Africa: a continental scale analysis 

Teresa Bonserio, Angelo Carlino, Matteo Giuliani, and Andrea Castelletti

As many developed countries prepare their transition to net zero emissions energy systems, Africa must plan a substantial expansion of its energy production sources, to meet the growing demand driven by increasing population and energy access. Among the existing capacity expansion potential, hydropower plays an important role in providing clean and cheap electricity. Yet, large hydropower schemes bring many negative social, environmental, and geopolitical externalities.

Least-cost optimization models constrained to satisfying predefined energy demands are used for large-scale energy system planning. Multi-objective optimization models can also incorporate environmental impacts in energy system planning, for instance by constraining the optimal solutions on GHG emissions or geomorphologic connectivity losses. However, these traditional techno-economic approaches overlook governance considerations, which are relevant to energy security, especially in unstable and conflictual political contexts. In fact, concerns about political instability are ranked among the main investment risks for foreign investors in developing countries. The subject becomes even more significant in transboundary river basins, where institutional stability and the absence of conflicts are crucial for effectively building and operating large hydropower projects.

To assess the political risks associated with the hydropower sector, we examine six pathways of energy generation for the African continent, from 2020 to 2050, developed using the OSeMOSYS-TEMBA energy system model. The model considers more than 600 existing and future hydropower projects in all countries of continental Africa, including available information for each individual power plant. Moreover, it incorporates ISIMIP2b scenarios to integrate coherently final energy demands, land-use change, and climate impacts on water availability.

For each scenario considered, the political risk deriving from the associated electricity generation and exchange patterns is characterized at the country-level using six energy-related dimensions. The more vulnerable transboundary river basins are then selected by intersecting the countries with high energy-related political risk and regions with high hydro-political conflict based on existing literature. We use a worst-case perspective for these basins and assume that electricity generated from planned or existing hydropower projects would not be exchanged between co-riparian countries due to the lack of cooperation. Finally, the impacts on the energy system are re-evaluated for the resulting cost-optimal energy system reconfiguration, and the difference with the fully connected solution is assessed.

Our results show that integrating political stability in energy system planning can produce precise spatial information about potential risks. Indeed, the lack of cooperation in transboundary river basins affected by high political instability can emphasize pre-existing vulnerabilities. Since this issue severely influences decisions related to energy planning on a continental scale, energy analysts can improve energy security using these results to design capacity expansion robust to political shocks.

How to cite: Bonserio, T., Carlino, A., Giuliani, M., and Castelletti, A.: Political instability influence on hydropower planning in Africa: a continental scale analysis, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16319, https://doi.org/10.5194/egusphere-egu23-16319, 2023.

In recent years, research on the water-energy-land (WEL) nexus has grown significantly not least because of the highly interconnectedness of the respective domains, but also for the crucial nature-economy interactions that underpin the future of our planet. With climate change and biodiversity crises looping, our conventional siloed biophysical and economic models are no longer adequate at providing prudent guidance to the interrelated sustainability questions. A new approach is urgently needed to tackle the issues of nature and the economy. In this research, we are developing a global-scale dynamic system model of nature, macroeconomy and finance that gives guidance on the crucial policy questions on the WEL nexus and biodiversity dynamics. We provide a critique of the existing modeling approaches, our novel conceptualization for a multidimensional model - with crucial elements, interactions, and underlining theories - which provides insights into the underlying source of biodiversity loss and the trade-off between different economic activities to safeguard livelihoods and achieve the so-called ‘nature positive’ pathways.

How to cite: Ilyas, A.: Reconceptualizing macroeconomic dynamics of water-energy-land for nature positive development pathways, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16496, https://doi.org/10.5194/egusphere-egu23-16496, 2023.

This research investigates the interconnections between water, energy, and land systems in the context of a long-term assessment of transition paths to achieve the Sustainable Development Goals (SDGs). It highlights the importance of integrated methods and addresses the complexity, interdependence, and uncertainty of climate change's impacts on natural systems and technology in the water, energy, and land sectors. The research utilizes two Integrated Assessment Models (MESSAGEix-GLOBIOM and IMAGE) to assess the long-term resources, supply, and demand of these sectors, together with the regional and sectoral reforms required to achieve the SDGs. It demonstrates how various locations and sectors would be affected by climate feedback under various climate mitigation scenarios. 

The study concludes that changes in water availability, that influence agriculture, water and sanitation access, hydropower potential, and power plant cooling technologies, constitute the largest proportion of climate impacts and the prime source of uncertainty. Furthermore, scenario analysis is used to understand the relationship between the SDGs and climate impacts in the absence of climate policies. The findings demonstrate that considerable progress towards the trajectories of the nexus SDGs resulted in strong synergies and interactions across the energy-water and land nexus components, irrespective of climate factors. Additionally, the study demonstrates that ambitious and healthy dietary modifications and a reduction in food waste can result in a decrease in global food demand, irrigation withdrawals, and emissions. Changes in the land sector can reduce overall SDG policy costs and energy and water expenditures, while strengthening the needs of the poor. Improving wastewater treatment and establishing more efficient water management technologies has socioeconomic and environmental advantages and can alleviate stress on freshwater withdrawals in locations that are water stressed. 

The study also shows that some regions, such as the Middle East and South Asia, are more vulnerable to climate impacts on the water sector and may require more extensive investments in water efficiency. In addition, it stresses that supplying households with electricity and clean cooking services can stimulate energy demand in emerging economies, but widespread adoption would require an increase in household incomes, notably in South Asia and Sub-Saharan Africa. Overall, the study highlights the importance of exploring the effects of climate change on natural and technological systems in the water, energy, and land sectors, as well as the relevance of implementing a coordinated strategy to achieving the Sustainable Development Goals. It also demonstrates the inter - dependencies and potentials of various sectors to achieve the SDGs while addressing the challenges they face because of climate change. 

How to cite: Awais, M., Vinca, A., Byers, E., Fricko, O., Frank, S., Krey, V., and Riahi, K.: Leveraging Integrated Assessment Models to access climate feedbacks on Water, Energy, and Land Systems: An Evaluation of Regional and Sectoral Transformations for Achieving the Sustainable Development Goals , EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16585, https://doi.org/10.5194/egusphere-egu23-16585, 2023.

EGU23-16592 | ECS | Posters virtual | HS5.7

Climate mitigation using wood in the Netherlands: a modelling approach from family home to national scale 

Jaap Bos, Jikke van Wijnen, Angelique Lansu, and Winnie Leenes-Gerbens

Abstract

Forests mitigate climate change by storing CO2 as wood and providing wood for products with a long economic residence time. This study examined the extent to which common Dutch homogeneous forests can contribute to climate mitigation if the harvested wood is processed into products. A model was set up which calculates the CO2 stock in the atmosphere for varying residence times of harvested wood in the economy and also determines the influence of this residence time on the optimal harvest age. Existing yield tables of Dutch homogenous forest were used as input data. This study showed that homogeneous forests in the Netherlands can extract a maximum of between 7 and 17 Mg of CO2 per hectare annually, depending on the tree species. For all tree species, the CO2 extracted from the atmosphere approaches this maximum as the residence time in the economy increases. The optimum felling age is not fixed, but varies depending on the economic residence time. The construction of 660,000 wooded single-family homes until 2050 with a lifetime of 150 years will remove an average of 1,5 Tg from the atmosphere annually. If the total forest area in the Netherlands is used to store wood in the economy for 150 years, an average of almost 6 Tg will be extracted annually. This is relatively low compared to the annual Dutch CO2 emissions of 150 Tg, but it is an option that fits well into the mix of other options that can contribute to climate change mitigation.

How to cite: Bos, J., van Wijnen, J., Lansu, A., and Leenes-Gerbens, W.: Climate mitigation using wood in the Netherlands: a modelling approach from family home to national scale, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16592, https://doi.org/10.5194/egusphere-egu23-16592, 2023.

EGU23-17268 | Orals | HS5.7

Inclusive Outscaling of the Agricultural Land Afforestation Agro-ecosystem REstoration ACTions in Heraklion, Greece 

Ioannis Daliakopoulos, Irene Christoforidi, Ioannis Louloudakis, Dimitrios Papadimitriou, and Thrassyvoulos Manios

Land degradation and desertification are considered major threats for the present and future of Mediterranean arid and semiarid agro-ecosystems (Daliakopoulos et al., 2017). Long-term anthropogenic pressure on forest and agricultural lands, combined with abiotic factors and the global trend of accelerated dryer climate and dryland expansion, create an uncertain and unstable living environment which has been demonstrated to increase poverty and force domestic and even cross-border migration. While our understanding and the flow of information about these threats is unprecedented, challenges persist and uptake of good practices by stakeholders is hindered by constraints and barriers both biophysical and socioeconomic (Daliakopoulos, 2022). For example, in one of the pioneer institutional initiatives aiming to enhance long-term forest resources and combat soil erosion and desertification by promoting forestry as an alternative form of land use, the Agricultural Land Afforestation (ALA) Program (Regulation 2080/92) introduced compensations for the income loss incurred during the non-productive period of afforested agricultural land. However, awareness about the Program by landowners, and the overall effectiveness of afforestation both in forestation success and in reducing soil erosion remains uncertain (Arabatzis et al., 2006; Nunes et al., 2011). In this context, the premise of the REACT4MED Project is that massive and effective land restoration actions need not only to make sense from an environmental point of view, but to also be socially acceptable, economically viable (Daliakopoulos & Keesstra, 2020), and have measurable impact, thus combining good practices with organic and inclusive transformation of all social actors. Here we present an overview of the effectiveness of the former ALA in the REACT4MED Pilot Area of Heraklion and outlines the supporting actions, both top down and bottom up, planned during the REACT4MED Project to increase the effectiveness of the forthcoming ALA Program by combining good practices with organic and inclusive transformation of all social actors.

References

Arabatzis, G., Christopoulou, O., & Soutsas, K. (2006). The EEC Regulation 2080/92 about forest measures in agriculture. International Journal of Ecodynamics, 1(3), 245–257. https://doi.org/10.2495/ECO-V1-N3-245-257

Daliakopoulos, I. N. (2022). Sustainable Soil and Water Management for Combating Land Degradation and Desertification and Promoting Mediterranean Ecosystem Restoration: The REACT4MED Concept. Third World Conference on the Revitalization of the Mediterranean Diet, 28.

Daliakopoulos, I. N., & Keesstra, S. (2020). TERRAenVISION: Science for Society. Environmental issues today. Science of the Total Environment, 704. https://doi.org/10.1016/j.scitotenv.2019.135238

Daliakopoulos, I. N., Panagea, I. S., Tsanis, I. K., Grillakis, M. G., Koutroulis, A. G., Hessel, R., Mayor, A. G., & Ritsema, C. J. (2017). Yield Response of Mediterranean Rangelands under a Changing Climate. Land Degradation & Development. https://doi.org/10.1002/ldr.2717

Nunes, A. N., de Almeida, A. C., & Coelho, C. O. A. (2011). Impacts of land use and cover type on runoff and soil erosion in a marginal area of Portugal. Applied Geography, 31(2), 687–699. https://doi.org/10.1016/J.APGEOG.2010.12.006

Acknowledgements

This work has received funding from REACT4MED: Inclusive Outscaling of Agro-Ecosystem Restoration Actions for the Mediterranean. The REACT4MED Project (grant agreement 2122) is funded by PRIMA, a program supported by Horizon 2020.

How to cite: Daliakopoulos, I., Christoforidi, I., Louloudakis, I., Papadimitriou, D., and Manios, T.: Inclusive Outscaling of the Agricultural Land Afforestation Agro-ecosystem REstoration ACTions in Heraklion, Greece, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17268, https://doi.org/10.5194/egusphere-egu23-17268, 2023.

Of all the natural resources available to humankind, water holds a prominent place, particularly because of its importance for human livelihood. Savelugu district in northern Ghana is characterized by unpredictable rainfall patterns with periodic and perennial water shortages. The distance people travel to fetch water and the person-hours spent in search for water affect productivity, economic livelihood, and health and education benefits. Provision of potable water supply to these communities is expected to bring not only health, education benefits but also increase in sanitation and hygiene practices. Static water levels (SWLs) of 19 wells in the study area were collected, analyzed and compared to the initial SWLs measured when the wells were immediately drilled and constructed. The SWL data was subjected to paired samples T-test (with α = 0.05). From the results, there was significant difference in the SWL immediately after drilling and construction (µ = 12.15, σ = 7.50) and SWL after at least 10 years (µ = 17.81, σ = 10.29); t (18) = -3.7, P = 0.002. Lowered groundwater levels were recorded in all wells measured. This can lead to drying up of some of the wells whose difference between the current SWL and well depth is close. There must be strong advocacy, development and implementation of IWRM plans to help address the problem of inadequate WASH in the study area.

How to cite: Acheampong, A.: Lowering of groundwater levels and their effect on Water, Sanitation and Hygiene services in the Savelugu District, Northern Region of Ghana, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-139, https://doi.org/10.5194/egusphere-egu23-139, 2023.

Agriculture, in general, has a long production cycle and is affected by many endogenous and exogenous uncertainty factors. Changes in rainfall patterns, maximum or minimum temperature, types and amounts of fertilizer input, timing, availability of irrigation water, and soil quality can drastically change the agricultural yield. In developing countries such as India, where more than half of countries population is engaged in agriculture, and the whims of nature may affect the agricultural output, it is essential to check how the entire agricultural system reacts to the changes in climatic parameters and anthropogenic practices. This study analyses agricultural trends in four primary staple crops, trends in climatic parameters, and anthropogenic inputs in Indian districts. Significant trends were detected and quantified using the non-parametric Mann-Kendall (MK) test, modified MK test, and Theil-Sen estimator at a 5% significance level. Spearman’s correlation test is used to determine the contributing factors to the changes in agricultural yield. Rice, Wheat, Pearl Millet, and Maize yields have shown significant increasing trends in a large number of the districts. Despite decreases in the gross cropped area in the majority of the districts, the trends in production are mostly positive. According to Spearman’s Rho correlation test, the increase in fertilizer consumption in most districts and the increase in crop-wise irrigated land in many districts are the significant reasons for the increase in yields. The rainfall did not change much compared to maximum and minimum temperatures at both the annual and seasonal levels. Although there were significant climatic changes in the last three decades, the correlation with agricultural yield is mostly insignificant.

How to cite: Sarkar, N. and Ray, S.: Analysis of Agricultural and Climatic trends in Indian Districts and finding the contributing factors in recent Indian Agricultural Outputs, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-653, https://doi.org/10.5194/egusphere-egu23-653, 2023.

EGU23-1916 | ECS | PICO | HS7.3

Modeling the potential of management options to reduce irrigation demand in Western Switzerland 

Malve Heinz, Christoph Raible, Bettina Schaefli, and Annelie Holzkämper

European Agriculture is experiencing the consequences of summer droughts and heatwaves in form of quality and quantity losses for numerous crops and feed production. Water availability for irrigation in the vital summer and fall months is decreasing and therefore, irrigation will most likely not be able to sufficiently mitigate the effects of droughts and heat in the future. Thus, approaches that reduce the need for irrigation are required. We investigate potential water-use reduction strategies based on a modelling framework applied to a selected case study in Western Switzerland, the Broye catchment. The region is characterized by intensive agricultural use and drought-related irrigation bans in summer. In the first step of our project, we quantify the total irrigation demand under current and future climate conditions using the soil-water-atmosphere-plant model SWAP. SWAP mainly simulates water and solute flow in soil as well as vegetation growth by solving a set of equations such as the Richards equations. Irrigation demand is quantified by applying this 1D model to the full range of climatic, soil and land use conditions prevailing in the selected catchment. The model calculates both the irrigation requirements and the yield of various irrigation-intensive crops currently grown in the region, such as potatoes, maize, or sugar beet. In a second step, we use the model to assess the efficiency of different management options to reduce the water demand, such as mulching, organic amendments, biochar application, different tillage methods or the cultivation of better-adapted crops. In future work, we will couple the field-scale model to a catchment-scale rainfall-runoff model to assess the impact of a large-scale application of such measures on the water balance of the catchment.

How to cite: Heinz, M., Raible, C., Schaefli, B., and Holzkämper, A.: Modeling the potential of management options to reduce irrigation demand in Western Switzerland, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1916, https://doi.org/10.5194/egusphere-egu23-1916, 2023.

EGU23-2603 | PICO | HS7.3

Rainwater harvesting as climate change adaptation strategy for durum wheat production in Sardinia 

Francesco Viola, Roberto Deidda, Salvatore Urru, and Elena Cristiano

The Mediterranean region is widely recognized as a climate change hotspot, where, mainly due to the increase of CO2 concentration, both historical records and future climate models’ projections reveal an increase of the daily average temperature and a reduction of the mean annual precipitation, with less frequent but more intense rainfall events. These changes could have strong impacts on the durum wheat production, and consequently to the food chain that derives from it. Water availability is expected to be the main limiting factor in the durum wheat growth, which is usually rainfed in Mediterranean region. On the other hand, CO2 increase may act as a counterbalance factor, by increasing the water use efficiency. In this work, within the framework of the H2020 European Union project ARSINOE (“Climate-resilient regions through systemic solutions and innovations”), we investigated the possibility to adapt durum wheat production to climate changes, compensating the rainfall reduction with emergency irrigation derived from a rainwater harvesting system, with the aim to keep constant the durum wheat production or alleviate the yield reduction. The Aquacrop model, a crop growth model developed by FAO’s Land and Water Division, has been calibrated to reproduce the actual durum wheat production in the Campidano region in Sardinia (Italy), implementing the local climate and soil characteristics. The model has been then used to simulate the crop production in correspondence of different bias corrected future climate scenarios, which foreseen an average rainfall reduction and increase of average temperature and CO2 concentration in the atmosphere. A rainwater harvesting system to collect rainfall from the rooftops or impervious surface within the cultivated area (100m2/ha) has been designed and the volume for potential emergency irrigation has been estimated year by year. Preliminary results show the importance of implementing rainwater harvesting systems to provide emergency irrigation and sustain durum wheat production in a context of climate changes.

Acknowledgments

This project has received funding from the European Union’s Horizon H2020 innovation action programme under grant agreement 101037424.

How to cite: Viola, F., Deidda, R., Urru, S., and Cristiano, E.: Rainwater harvesting as climate change adaptation strategy for durum wheat production in Sardinia, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2603, https://doi.org/10.5194/egusphere-egu23-2603, 2023.

With the impact of climate change and the main rainfall seasons in Taiwan are concentrated in the plum rain season from May to June and the typhoon season from July to September each year.There are significant differences in rainfall and spatial and temporal distribution between the wet season and the dry season,the droughts will occur and even lead to severe water shortages, such as the worst drought in half a century in 2021.From a macroscopic spatial scale, for example, the El Niño phenomenon and solar activity may have a certain impact on the overall climate and water resources of the earth.Therefore, this study analyzes the correlation between rainfall and large-scale influencing factors such as sunspots, El Niño-Southern Oscillation,and uses machine learning models to predict and classify rainfall under different conditions,the prediction accuracy rate through historical data can reach 89.9% , with sunspots as the most significant factor. It is hoped that relevant units can provide reference for water resources management and planning.

How to cite: Weng, Z.-H. and Lin, Y.-C.: Establishing a macroscopic-scale rainfall climate and water resources estimation model by machine learning method, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3008, https://doi.org/10.5194/egusphere-egu23-3008, 2023.

EGU23-3528 | ECS | PICO | HS7.3

Effects of heat and drought stress and their co-occurrence on winter wheat yields in Germany under climate change 

Rike Becker, Bernhard Schauberger, Ralf Merz, Stephan Schulz, and Christoph Gornott

In our changing climate, heatwaves and droughts and their spatio-temporal co-occurrences are likely to intensify. This will inevitably challenge future agricultural production and calls for adaptation strategies to protect future yields. To find suitable climate adaptation strategies for Germany’s major staple crop - winter wheat - it is important to know how heat stress, drought stress or their compound effects drive wheat yield failures. The principal aim of this study is, therefore, to quantify the impacts of heat, drought, and their compound effects on winter wheat yields in Germany, in a spatially and temporally discrete manner.

To address our aim, we develop a statistical crop-climate model for the time period 1991-2019 at the county level. We first create agroclimatic proxies for heat stress, drought stress and their compound effects and use these to construct a separate time series model with the addition of time-dependent interaction terms. Our approach constructs separate regression models for each county, based on common elements that allow for comparing and jointly interpreting individual models.

Preliminary results show that more than 50% of Germany’s wheat yield variability can be explained by climate effects. Compound effects of heat and drought stresses are responsible for approx. 42% of the variability in Germany’s winter wheat yields. Drought stress alone explains approx. 7%, with higher impacts in the east of the country, and heat stress alone explains approx. 3% of the year-to-year yield variability, with higher impacts in the north-west of Germany. The results confirm the importance of compound effects and underline their dominating impacts on winter wheat yields, when compared to individual heat and water stress impacts – a finding which should guide future adaptation strategies. Furthermore, our study shows that heat stress is becoming increasingly important for wheat yield failure in Germany – alone and in conjunction with moisture stress.

In conclusion, we suggest that climate change adaptation strategies for winter wheat in Germany should focus on combined measures against drought and heat extremes. While the increase of multi-stress resilience should be the main goal for entire Germany, north-western areas should prioritize strategies to increase heat resilience and eastern areas should prioritize strategies to increase drought resilience.

How to cite: Becker, R., Schauberger, B., Merz, R., Schulz, S., and Gornott, C.: Effects of heat and drought stress and their co-occurrence on winter wheat yields in Germany under climate change, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3528, https://doi.org/10.5194/egusphere-egu23-3528, 2023.

current legislation requires the inspection and calibration of operational survey radiation monitoring instruments used in nuclear medicine and radiotherapy departments as well as in any field that uses ionizing radiation sources. As a result, Morocco's national secondary standard dosimetry laboratory provides reliable calibration results with high accuracy while adhering to national and international radiation protection standards and covering the various measurement ranges, using the attenuators offered by the automated Gamma G10 irradiator or the validated beam qualities produced by the X-ray irradiator type X80-320kV as required. The measurements’ reliability was demonstrated by participation in a comparison program launched by the International Atomic Energy Agency (IAEA).

This work aims to develop a digital graphical user interface designed for the calibration of measuring instruments in radiation protection through the programming language Python, which serves to facilitate the establishment of all operations and calculations related to the determination of calibration factors and measurement uncertainties according to the ISO 4037 standard in a minimum time that allows to process several instruments during the day with high accuracy, while minimizing the sources of errors, this interface allows the recording of calculations as well as the establishment and electronic archiving of the calibration certificate in pdf format ported from PHP FPDF.

How to cite: Belhaj, O. E., Boukhal, H., and Belhaj, S.: Digital graphical user interface as a facilitator for the calibration of radiation monitoring instruments according to ISO 4037:2019 at the national secondary standard dosimetry laboratory of morocco, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4503, https://doi.org/10.5194/egusphere-egu23-4503, 2023.

Groundwater is an essential source of water in Taiwan, and its long-term overuse has resulted in water resource problems that have become a potential crisis in the Zhuoshui River Basin. This overuse of groundwater may also lead to subsidence, which can have significant consequences for the area and its infrastructure. The lack of complete observations of groundwater extraction in Taiwan due to historical factors has made it difficult to accurately understand and manage the amount of water being taken, particularly for agricultural purposes.In view of this, this study uses time series data from 87 agricultural groundwater wells in Huwei Town, Yunlin County from January 2016 to July 2017, and time series data on agricultural well electricity usage in the Changshui River Basin, combined with other attribute data, to understand farmers' water pumping behavior using data mining methods and to estimate the amount of water taken in the Huwei area using machine learning.This study obtained the spatial and temporal distribution of groundwater withdrawals in the Huwei area in 2018.

How to cite: Tseng, Y. K. and Yu, H. L.: Using Time Series Data and Machine Learning Estimating Agricultural Groundwater Extraction in Huwei Town, Taiwan, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5173, https://doi.org/10.5194/egusphere-egu23-5173, 2023.

EGU23-5551 | ECS | PICO | HS7.3

Probabilistic modelling of water distribution networks and resilient reduction of leakages: Large scale application to the city of Patras in western Greece 

Athanasios V. Serafeim, George Kokosalakis, Roberto Deidda, Nikolaos Th. Fourniotis, Irene Karathanasi, and Andreas Langousis

Modeling of leakages in Water Distribution Networks (WDNs) is a vital task for all water related professionals and experts towards the development of management practices and strategies, which aim at the reduction of water losses (leakages) and the associated financial cost and environmental footprint. In the current work we develop an integrated, theoretically founded, and easily applicable probabilistic framework for resilient reduction of leakages in WDNs, which combines: a) a set of conceptually and methodologically different probabilistic approaches for minimum night flow (MNF) estimation in WDNs based on statistical metrics (Serafeim et al., 2021 and 2022a), and b) a combination of statistical clustering and hydraulic modeling techniques for the rigorous and user unbiased partitioning of WDNs into pressure management areas (PMAs) or district metered areas (DMAs), which seeks for minimization of leakages while maintaining an acceptable level of the network’s hydraulic resilience (Serafeim et al., 2022b). The efficiency of the introduced framework is tested via a large-scale real-world application to the water distribution network of the City of Patras, the largest smart water network (SWN) in Greece, which covers an area of approximately 27 km2 and serves more than 213000 consumers (based on data from the Hellenic Statistical Authority and the Municipality of Patras), with more than 700 km of pipeline grid (mainly HDPE and PVC pipes).

Acknowledgements

The research work was supported by the Hellenic Foundation for Research and Innovation (H.F.R.I.) under the “First Call for H.F.R.I. Research Projects to support Faculty members and Researchers and the procurement of high-cost research equipment grant” (Project Number: 1162).

References

Serafeim, A.V., Kokosalakis, G., Deidda, R., Karathanasi I. and Langousis A (2021) Probabilistic estimation of minimum night flow in water distribution networks: large-scale application to the city of Patras in western Greece, Stoch. Environ. Res. Risk. Assess., https://doi.org/10.1007/s00477-021-02042-9.

Serafeim, A.V., G. Kokosalakis, R. Deidda, I. Karathanasi and A. Langousis (2022) Probabilistic Minimum Night Flow Estimation in Water Distribution Networks and Comparison with the Water Balance Approach: Large-Scale Application to the City Center of Patras in Western Greece, Water, 14, 98, https://doi.org/10.3390/w14010098.

Serafeim, A.V., G. Kokosalakis, R. Deidda, N. Th. Fourniotis and A. Langousis (2022) Combining statistical clustering with hydraulic modeling for resilient reduction of water loses in water distribution networks: Large scale application to the city of Patras in Western Greece, Water, 14(21), 3493. https://doi.org/10.3390/w14213493.

 

How to cite: Serafeim, A. V., Kokosalakis, G., Deidda, R., Fourniotis, N. Th., Karathanasi, I., and Langousis, A.: Probabilistic modelling of water distribution networks and resilient reduction of leakages: Large scale application to the city of Patras in western Greece, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5551, https://doi.org/10.5194/egusphere-egu23-5551, 2023.

EGU23-5567 | PICO | HS7.3

A probabilistic approach for detection and classification of PRV malfunctions in the water distribution network of the city of Patras in western Greece 

Anastasios Perdios, George Kokosalakis, Nikolaos Th. Fourniotis, Demetris Pantzalis, and Andreas Langousis

Effective management of water losses in water distribution networks (WDNs) still remains a demanding task, as the temporal and spatial variability of water resources under changing climatic conditions and the increasing needs for drinking water may lead to freshwater shortages. In this context, pressure management strategies are widely adopted in an effort to reduce the water losses in the supply and distribution parts of water networks and, consequently, deescalate their environmental footprint. Installation of pressure reducing valves (PRVs) at critical locations of WDNs plays a central role in pressure regulation strategies, as PRVs reduce the upstream pressure to a set outlet pressure (i.e., downstream of the PRV), usually referred to as set point. Perdios et al. (2022) developed a novel statistical framework and applied it to an existing pressure management area (PMA) of the city of Patras in western Greece, aiming at early detection of PRV malfunctions that may significantly influence network’s operation and the corresponding lifetime of related infrastructure. The results showed that the suggested methodology allows reliable detection of critical malfunctions at least 2 days prior to flow disruptions. Ιn this study, we calibrate and implement Perdios et al. (2022) statistical framework, using pressure data for a 4-year period from 01/Jan./2017 to 26/Nov./2020 from several important PMAs of the WDN of the city of Patras, aiming towards better understanding of the causes of the malfunctions, by decomposing the observed pressure deviations from the set point to systematic and random error components.

Acknowledgements

The research work has been conducted within the project PerManeNt, which has been co-financed by the European Regional Development Fund of the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation under the call RESEARCH – CREATE – INNOVATE (project code: T2EDK-04177).

Reference

Perdios A., G. Kokosalakis, N. Th. Fourniotis, I. Karathanasi and A. Langousis (2022) Statistical framework for the detection of pressure regulation malfunctions and issuance of alerts in water distribution networks, Stoch. Env. Res. Risk Asses., https://doi.org/10.1007/s00477-022-02256-5

How to cite: Perdios, A., Kokosalakis, G., Fourniotis, N. Th., Pantzalis, D., and Langousis, A.: A probabilistic approach for detection and classification of PRV malfunctions in the water distribution network of the city of Patras in western Greece, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5567, https://doi.org/10.5194/egusphere-egu23-5567, 2023.

EGU23-10057 | ECS | PICO | HS7.3

Building a smart green system to control water leakage and monitor drinking water quality in the water supply system of Paramythia city, Greece: the case of SMASH project 

Angelos Chasiotis, Stavroula Tsitsifli, Konstantinos Panytsidis, Vegard Nilsen, Nikolaos Mantas, Dimitrios Theodorou, Thomas Kyriakidis, Stefanos Chasiotis, Maria Bousdeki, Elissavet Feloni, Harsha Ratnaweera, Panagiotis Nastos, and Malamati Louta

Water leakage is acknowledged as one of the most important issues that drinking water supply systems are facing worldwide. Non-Revenue Water is estimated to 346 million m3 per day and its cost/value is estimated to 39 billion USD per year. At the same time drinking water quality is jeopardized from the water intake points to the consumer’s tap, even during normal operating conditions.

ICT support water utility operators to improve the operational capacity of their water supply system. A smart green system to control water leakage and monitor drinking water quality in the water supply system of Paramythia city will be built in the context of SMASH project. It consists of: (a) IoT system comprising three local control stations, installed in selected parts of the water supply network, monitoring water quantity&quality parameters in real time; (b) the hydraulic simulation model of the water supply system of Paramythia; (c) a virtual sensors system, which will be used for water quality prediction; (d) a Decision Support System (DSS) for leakage detection and optimal management of water supply system parameters in an automated manner.

The DSS will detect and locate water leakages within the DMA zone and inform the operators for excessive values in drinking water quality parameters. The DSS will use as inputs the data from the IoT system, will interact with the hydraulic simulation model, and obtain the water quality data from the virtual sensors. All these data will be processed by the DSS logic in the backend subsystem. The IoT and the hydraulic simulation data, based on the digital twin of the water supply system, are used for the calculation of specific performance indicators related to water leakage, such as well-known IWA indicators: water losses, ILI, etc. Calculating the divergences between the PI values observed & the ones representing the optimal operation of the water network without leakages and setting appropriate thresholds, the DSS will detect the leakage, while several different scenarios will run in hydraulic simulation. The frontend subsystem of the DSS will be able to visualize the water distribution network, statistical values of water quantitative & qualitative parameters. It will provide alarms in case of leakage or exceedance of water quality parameters’ values and it will show the leakage location in a map. The architecture of the smart green system, currently under development, is depicted in Fig.1.

Figure 1. The DSS for the water parameters management in the water supply system

Keywords: Drinking water; water quality; leakage; virtual sensors; smart system; decision support.

Acknowledgement: This work is co-financed by EEA Grants 2014 – 2021 and Greek Public Investments Program.

  • Liemberger, R., & Wyatt, A. (2019). Quantifying the global non-revenue water problem. Water Supply19(3), 831-837.
  • Antzoulatos G., Mourtzios C., et al (2020), Making urban water smart: the SMART-WATER solution. Water Science & Technology, 82(12), 2691–2710.
  • Alegre, H., Baptista, et al (2016). Performance indicators for water supply services. 3rd IWA publishing.

How to cite: Chasiotis, A., Tsitsifli, S., Panytsidis, K., Nilsen, V., Mantas, N., Theodorou, D., Kyriakidis, T., Chasiotis, S., Bousdeki, M., Feloni, E., Ratnaweera, H., Nastos, P., and Louta, M.: Building a smart green system to control water leakage and monitor drinking water quality in the water supply system of Paramythia city, Greece: the case of SMASH project, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10057, https://doi.org/10.5194/egusphere-egu23-10057, 2023.

By calculating the water demand and programming a fine irrigation project, the management and cultivating efficiency of traditional agriculture can be greatly improved. Taking rotational irrigation for example, the efficiency of irrigation can be maximized by adjusting water distribution routes, irrigation area allocation, and irrigation schedule planning. However, in actual operation, some problems are often encountered, such as how to persuade farmers and promote the designed irrigation project, and the negotiation of various stakeholders. Generally, due to the complexity of the irrigation design model, it is impossible to have an effective and immediate communication or presentation. Therefore, this study introduces the Bayesian network to presents the key points of the irrigation project after simplifying the relationship. In addition to being simpler for stakeholders to understand, it is also possible to adjust various parameters in time to obtain rough estimation results.

The research area of this study is a 100-hectare farmland, which is located in Kinmen County, Taiwan. For many years, local farmers have only relied on precipitation to cultivate sorghum, wheat and other crops. However, the precipitation in Kinmen is semiarid and unstable. In the past five years, the annual rainfall has been lower than the average in previous years, which directly led to a very bleak crop harvest. Therefore, we hope to establish an irrigation project in Kinmen, using recycled water as the water source to provide local farmers with a reliable water source.

The Bayesian network used in this study is a directed acyclic graphical (DAG) model based on conditional probability and Bayesian theorem to express the possible relationship between variables. In terms of operation, the different influencing factors in the research topic are converted into nodes, and the relationship between nodes is given by different conditional probabilities. This study uses GeNIe to establish a Bayesian network that can be used to estimate water profit and loss and other results. This Bayesian network can be divided into four sub-blocks, which are the relevant data of the irrigation area, the water demand, the water supply, and the final result calculation. Therefore, when the stakeholders are negotiating the irrigation project, they can discuss the different estimation results by adjusting each node of the first three sub-blocks.

How to cite: Su, Y. and Yu, H.-L.: Application of Bayesian Network in Analysis and Management of Agricultural Water - Taking Kinmen for Example, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10515, https://doi.org/10.5194/egusphere-egu23-10515, 2023.

Assessing the Sustainability in Water Use under
Different Agricultural Management Planning
in Yeongsan-River Basin, South Korea

 

Yujong Jeong1, Hyun-woo Jo1, YanYan1, Minwoo Noh1, Woo-Kyun Lee1*

 

1 Department of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea

*E-mail: leewk@korea.ac.kr

(Address: Korea University, Anamro 145, Seongbukgu, Seoul 02841, Republic of Korea)

 

Abstract:

From the past, South Korea has been experiencing high level of water stress as reported by WRI, in 2013, and chronically imbalanced spatiotemporal water allocation. Yeongsan-river basin, where the biggest national breadbasket is located, is facing unequal water allocation among different water uses and inefficient water management under episodic water shortage conditions. Therefore, the main objective of this study was to analyse current water management and allocation scheme, and to evaluate 3 different agricultural management plans in terms of efficiency and equity. The Soil and Water Assessment Tool(SWAT) was applied to simulate the hydrological process and crop yield in the basin. The model was calibrated and validated using observed outflows to set adequate system parameters for the entire watershed. Crop water productivity and spatial-temporal-sectoral water distribution are utilized as the indices to evaluate different agricultural strategies. The results suggested that there was potential to improve both crop productivity and water allocation at the same time with the suggested plannings. Crop water productivity increased in all three strategies in order of on-farm management measures (precise agriculture), crop diversification (replacing rice to beans) and agroforestry (mixing trees and crops). The crop water productivity of on-farm measurement ranges from 5t/L to 13t/L and rises about 20% on average. In addition, it is found that applying the combination of different agricultural management measures could achieve better water allocation in terms of space and time, and between agriculture and ecosystem. The outcomes of this study can serve scientific-evidence policy and decision-making systems for sustainable agricultural society and ecosystem.

KeywordsHydrological Modelling, SWAT, Crop water productivity, Water allocation, Agricultural Management Planning, Yeongsan-River Basin

Acknowledgements: This work was supported under the framework of international cooperation program managed by the National Research Foundation of Korea (No. 2021K2A9A1A02101519).

 

 

How to cite: Jeong, Y.: Assessing the Sustainability in Water Use under Different Agricultural Management Planning in Yeongsan-River Basin, South Korea, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10943, https://doi.org/10.5194/egusphere-egu23-10943, 2023.

EGU23-10953 | ECS | PICO | HS7.3

Leveraging Hydroclimate and Earth Observation to Predict Grain Production in Sub-Saharan Africa 

Donghoon Lee, Frank Davenport, Shraddhanand Shukla, Laura Harrison, Greg Husak, Chris Funk, Michael Budde, James Rowland, Amy McNally, and James Verdin

The importance of forecasting agricultural production in Sub-Saharan Africa (SSA) is increasing for the management of agricultural supply chains, market forecasting, and targeting of food aid. In particular, agricultural forecasts enable governments and humanitarian organizations to respond more effectively to shocks in food production and price spikes resulting from extreme droughts. In this study, we use hydroclimate, earth observations (EO) and machine learning to develop an operational, sub-national grain production forecast system for a number of SSA countries, including food-insecure regions where rapid response is critical. Before creating the forecast, we collect and organize crop production data from the Famine Early Warning Systems Network in order to identify trends and variability in agricultural technology, climate, and vegetation. In addition, we demonstrate the capability of hydroclimate and EO data to capture favorable or unfavorable crop development conditions during the growing season. In addition, we demonstrate a unique capability that explains how EO characteristics influence current grain production forecasts, thereby enhancing the forecasts' reliability and efficacy. This research lays the groundwork for the development of a large-scale, operational crop yield forecasting system that will provide actionable predictions of food shocks for famine early warning and guide advanced preparedness and response strategies.

How to cite: Lee, D., Davenport, F., Shukla, S., Harrison, L., Husak, G., Funk, C., Budde, M., Rowland, J., McNally, A., and Verdin, J.: Leveraging Hydroclimate and Earth Observation to Predict Grain Production in Sub-Saharan Africa, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10953, https://doi.org/10.5194/egusphere-egu23-10953, 2023.

EGU23-11183 | ECS | PICO | HS7.3

Implications of 1.50C global warming for agricultural productivity over a global rice exporting region in Central India 

Shoobhangi Tyagi, Sandeep Sahany, Dharmendra Saraswat, Saroj Kanta Mishra, Amlendu Dubey, and Dev Niyogi

Water, food, and energy security are the major climate risks of global warming. The Paris Agreement proposed an ambitious target of limiting the rise in global mean surface temperature to well below 20C, and preferably to 1.50C, compared to the pre-industrial era. However, the implication of this policy discourse on the agricultural system is imperative for ensuring food security in the face of global warming. This research focuses on understanding the changes in water availability and rice productivity under 1.50C global warming over a global rice-exporting semi-arid watershed in Central India. Towards this goal, the mean climate under 1.50C of global warming was computed for 21 Coupled Model Intercomparison Project Phase 6 (CMIP6) Global Climate models (GCMs). For each GCM, the corresponding changes in blue-green water availability and rice productivity at 1.50C warming period were estimated under two global warming scenarios (SSP2-4.5 and SSP5-8.5) based on the semi-distributed Soil and Water Assessment Tool (SWAT). Results suggest that the green and blue water is projected to change by ~ -20% to 10 and ~ -50 to 20%, respectively. The rice yield is projected to reduce in the range of 5% to 50%, with an increase in local temperature (~10C) and a decrease in local precipitation (~20%) being the limiting factor. This study provides useful information on when the 1.50C global warming could reach and how it can affect the agricultural productivity of semi-arid watersheds across different global warming scenarios. This study will help develop appropriate strategies to reduce/alleviate the impacts of global warming and foster food security at the watershed-scale.   

How to cite: Tyagi, S., Sahany, S., Saraswat, D., Mishra, S. K., Dubey, A., and Niyogi, D.: Implications of 1.50C global warming for agricultural productivity over a global rice exporting region in Central India, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11183, https://doi.org/10.5194/egusphere-egu23-11183, 2023.

        Due to climate change, Taiwan's rainfall has become unstable in recent years, leading to short rainy seasons and low rainfall. In 2021, a severe drought occurred due to the lowest rainfall on record. Groundwater is essential for agricultural development, but less than 10% of wells are legal. Improper or excessive use of groundwater resources can cause serious disasters, such as sea intrusion and land subsidence. However, if the government and farmers extract groundwater effectively and sustainably, it will bring more flexibility to water management.

        In this study, a land subsidence model was conducted based on geological conditions and groundwater level. This study analyzes multi layer compaction monitoring well profiles, and further finds the correlation among the two main factors and subsidence. The goal of this study is to visualize which areas are more suitable for using groundwater and assist the government in water resource management. This study focuses on the Choshui river alluvial fan in Taiwan. A risk map of land subsidence for this area is made by evaluating two main factors, geological conditions and groundwater level.

How to cite: Su, S.-H. and Yu, H.-L.: Assessment of Land Subsidence based on Geological Conditions, Groundwater Levels in the Choshui River Alluvial Fan, Taiwan, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11879, https://doi.org/10.5194/egusphere-egu23-11879, 2023.

EGU23-12693 | ECS | PICO | HS7.3

Photo-driven processes for the removal of biotoxins derived from Harmful Microalgal Blooms 

Javier Moreno-Andrés, Sandra Lage, Ana Catarina Braga, Leonardo Romero-Martínez, Asunción Acevedo-Merino, Enrique Nebot, and Pedro R Costa

Harmful Algal Blooms (HABs) are increasing in frequency and magnitude globally. These episodes are associated with the generation of biotoxins, which pose a potential risk to human and animal health. Biotoxins notably affect aquaculture activities and shellfish production, which has a clear impact on food and human health. Consequently, it is sometimes necessary to close the harvesting areas until the organisms are decontaminated. These natural detoxification mechanisms depend largely on the type of toxin and physiology of the organism, resulting in lengthy processes that can cause severe economic losses to aquaculture activities. As the main goal of this communication, we propose a technological alternative for the degradation of marine biotoxins through the implementation of UV technology as a treatment for agricultural, environmental, and health-related purposes. Therefore, advanced photochemical processes should be evaluated for the efficient degradation of marine biotoxins. The toxin selected was okadaic acid (OA), which is a very stable diarrheal toxin (DSP) and has a great impact on shellfish production areas, e.g. on the Portuguese coast. First, irradiation experiments were performed under UV-A, UV-B, and UV-C irradiation. In general, the concentration remained similar after different UV exposures, indicating that there was no observable photodegradation of OA after 3 h of UV irradiation, detecting a maximum degradation of 19.5% (± 0.95) in the UV-C region, suggesting that OA is clearly resistant to UV photodegradation. Second, the combined UV/H2O2, UV/HSO5, and UV/S2O82 − processes were tested. Two different UV sources were evaluated: LED and low-pressure lamps (LP), performing OA exposure in distilled water and seawater, with a maximum UV exposure of 3 h. In general, a clear degradation of OA is observed in photochemical processes in distilled water, with a slight decrease in efficiency in the UV/H2O2 process with an LED irradiation source. In the case of UV/S2O82 − and UV/HSO5, both the LP lamp and LED achieved a total degradation of OA. In the case of the marine matrix, the effect is clearly inhibited for the UV/H2O2 process; however, for UV/ HSO5, salinity does not seem to affect OA degradation, obtaining practically 100% removal. The study of new UV-LEDs would favor aquaculture activities by increasing sustainability and health safety. Likewise, the results obtained might provide the basis for a possible scale-up of technological processes specifically designed for the minimization of marine biotoxins.

How to cite: Moreno-Andrés, J., Lage, S., Braga, A. C., Romero-Martínez, L., Acevedo-Merino, A., Nebot, E., and Costa, P. R.: Photo-driven processes for the removal of biotoxins derived from Harmful Microalgal Blooms, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12693, https://doi.org/10.5194/egusphere-egu23-12693, 2023.

EGU23-15429 | ECS | PICO | HS7.3

Effect of distance of crop canopy temperature observations on Crop Water Stress Index 

Aditi Yadav, Hitesh Upreti, and Gopal Singhal

The need for water management in the agriculture sector, which is a 70% consumer of global water resources, is imperative. For the same, a plant-based index called crop water stress index (CWSI) is widely being adopted for irrigation scheduling. An empirically derived CWSI is dependent on three parameters of canopy temperature (Tc), air temperature (Ta), and relative humidity (RH).This study was conducted by performing controlled crop experiments in the arid region of Uttar Pradesh state of India, which aims to evaluate the significance of height of Tc observations, taken from March to April 2022, on CWSI calculations for the wheat crop.This has been done by observing theTc by aiming the wheat crop from the top of the crown at two distances of 10 cm and 100 cm, respectively. Handheld remote sensingdevice known as infrared thermometeris used for the observation of canopy temperature. Variation in the height from 10 cm to 100 cm leads to a variation in the field of view from 51.28 sq. cm to 5128 sq. cm. The effect of enhanced area and the involvement of extra soiland vegetation pixels can be understood by this work. Five different irrigation regimes have been provided to study the effect of change in height for Tc observations. The regimes consist of five plots 1,2,3,4, and 5 with soil moisture depletion by the following percentage respectively: 50% in drip irrigation, 25% in drip irrigation, unregulated flood irrigation, 50% in flood irrigation, and no irrigation plot.Plot 2 has been used to formulatea lower baselinefor CWSI calculations. A lower baseline represents a non-water-stressed condition of the crop where the crop is provided with sufficient irrigation treatment leading towards negligible stress conditions. The lower baseline equations used for CWSI assessment for 10 cm and 100 cm height are -1.287(VPD) -2.19 and -1.214(VPD)-1.738, respectively. VPD represents vapor pressure deficit which is a function of Ta and RH. Upon increasing the height from 10 cm to 100 cm, Tc increased by 2.1%, 2.7%, 0.6%, 0.9%, and 1.3% for plots 1,2,3,4, and 5, respectively. This change in temperature led to a decrease in CWSI by 21.8%,36.4 %,9.2%, and 12.2% in plots 1, 2, 3, and 4 respectively. An increase in CWSI by 5.8% for a rise of 1.3% in Tc for plot 5 was also noted. Further coefficient of determination R2 was observed between CWSI at 10 cm height and CWSI at 100 cm height for all plots. It was observed to be 0.65, 0.50, 0.93, 0.93, and 0.87 for plots 1, 2, 3, 4, and 5, respectively. This study shows the effect of observation distance of crop canopy temperature on CWSI that can lead to the development of sampling procedures meant for CWSI studies.

How to cite: Yadav, A., Upreti, H., and Singhal, G.: Effect of distance of crop canopy temperature observations on Crop Water Stress Index, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15429, https://doi.org/10.5194/egusphere-egu23-15429, 2023.

Agricultural water use comprises the major part of the total water consumption in many countries, and Taiwan is no exception. However, urbanization and industrialization have triggered the competition for water among different sectors. Water is transferred to satisfy the daily need and industrial need, especially the need of high-tech industries, from the agricultural sector. Groundwater hence becomes an alternative water resource for agriculture, but the over-exploitation of groundwater resources also leads to some problems such as environmental degradation and land subsidence, and climate change has worsened the situation in the recent years.

In Taiwan, groundwater is one of the vital water resources for irrigation, especially when the first crop rice begins being cultivated in the late dry season in central Taiwan. Yunlin County located in central Taiwan is chosen as the study area, which is now facing severe issues about groundwater over-exploitation and suffering from land subsidence threatening the safety of Taiwan High Speed Rail. Because of the high water consumption, groundwater extraction from agriculture is deemed to be the major cause of the land subsidence and should be well monitored and reduced. However, farmers’ pumping behaviors are highly related to the national water allocation policy, food policy and the socioeconomic factors in the rural area. The top-down agricultural water management might not be sufficient and sustainable. Hence, in this study, we propose a participatory framework for agricultural water management using a Bayesian network. The framework tries to incorporate the main factors that affect decision making among different stakeholders, including the Water Resources Agency, Irrigation Agency, Agriculture and Food Agency, farmers, etc., and represent the causal relationship among factors through Bayes’ theorem, or the conditional probability tables (CPTs). The CPTs are constructed based on data, literature reviews and interviews with stakeholders. The key issues concerning different stakeholders are considered in the framework as well, such as surface water shortage for agriculture, land subsidence, and sustainability of agriculture in Yunlin. The network can be used to hold discussions with stakeholders and show the interactions of their decisions among others. The aim of this framework is to facilitate the discussions and formulate the strategies for sustainable agricultural water management with the aid of the intuitive and transparent structure of the Bayesian network.

How to cite: Lee, S.-Y. and Yu, H.-L.: Using Bayesian network to build a participatory framework for sustainable agriculture water management in Yunlin, Taiwan, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15459, https://doi.org/10.5194/egusphere-egu23-15459, 2023.

Irrigation plays a crucial role in alleviating the negative effects of drought on crop production. However, increasing competition for water by other sectors, such as industry and domestic use, increases the pressure on available water supplies. Under these circumstances, agricultural producers must be able to manage their available supplies efficiently to optimize irrigation water use. The objective of this research is to develop a decision support system (DSS) for optimizing irrigation scheduling for cotton production using Deep Reinforcement learning (DRL). Our approach uses multiple DRL algorithms that enable an intelligent agent to learn cotton irrigation needs in an interactive environment by trial and error using feedback from its past actions and experiences. Aquacrop is used as an environment (cotton field) simulator and is coupled with a DRL model to simulate crop yield for different actions taken by the agent. Our proposed software estimates the daily irrigation needs of a 7-acre crop field irrigated by a center pivot system located at Clemson University's Edisto Research and Education Center (REC), near Blackville, South Carolina. This new system enables a closed-loop control scheme to adapt the DSS to local perturbations such as soil moisture and rainfall variabilities.

How to cite: Umutoni, L.: An Intelligent Irrigation Decision Support System for Optimizing Cotton Water Use, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16787, https://doi.org/10.5194/egusphere-egu23-16787, 2023.

EGU23-142 | ECS | Posters on site | HS8.1.1

Aggregation Kinetics and Stability of Biodegradable Nanoplastics: Effects of Weathering and Proteins 

Yingxue Yu, Markus Flury, Anton Astner, Douglas Hayes, Tahsin Zahid, and Indranil Chowdhury

Plastic pollution caused by conventional plastics has promoted the development and application of biodegradable plastics. However, biodegradable plastics do not degrade readily in water, instead, they can generate countless micro- and nanoplastics. Compared to microplastics, nanoplastics are more likely to cause negative impacts to the aquatic environment due to their smaller size. The impacts of biodegradable nanoplastics highly depend on their aggregation behavior and colloidal stability, which still remain unknown. Here, we studied the aggregation kinetics of polybutylene adipate co-terephthalate (PBAT) nanoplastics in both NaCl and CaCl2 solutions before and after artificial weathering. We further studied the effect of proteins on aggregation kinetics with both negatively charged bovine serum albumin (BSA) and positively charged lysozyme (LSZ). We found that divalent cations (Ca2+) destabilized PBAT nanoplastics more aggressively than monovalent cations (Na+); weathering stabilized PBAT nanoplastics profoundly, with no aggregation observed in NaCl nor in CaCl2; both BSA and LSZ promoted the aggregation of pristine PBAT nanoplastics, with LSZ showing more pronounced effect. These results suggest that biodegradable nanoplastics, especially weathered biodegradable nanoplastics, are highly stable in the aquatic environment.

How to cite: Yu, Y., Flury, M., Astner, A., Hayes, D., Zahid, T., and Chowdhury, I.: Aggregation Kinetics and Stability of Biodegradable Nanoplastics: Effects of Weathering and Proteins, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-142, https://doi.org/10.5194/egusphere-egu23-142, 2023.

EGU23-196 | ECS | Posters on site | HS8.1.1

Foam Composition and Surfactant Sources in an Urban Foaming Lake: A Comprehensive Analysis 

Reshmi Das, Chanakya Hoysall, and Lakshminarayana Rao

Foaming of surface water bodies is a common concern of many major metropolitan cities globally. These hideous and persistent foams disturb aquatic ecosystems and also emit an obnoxious stench. These foams also overflow onto the surrounding roads, causing pedestrians discomfort and traffic disruption. Even though foaming of the aquatic system is a widespread phenomenon, it is not entirely scientifically understood yet. The central unexplored question in this domain is - what compounds make up a foam? To answer this question, it is vital to understand the physics of foaming, the properties of a compound that helps in foaming, and its chemical/physical influence on the distribution of other compounds and species in a water body.

 Foam is caused by surface-active compounds called surfactants. In aquatic environments, the surfactants may be either endogenous or anthropogenic in origin. In nutrient-rich waterbodies, decaying plants and microorganisms can be a potential endogenous source of surfactants. Commercially used surfactants in households and industries find their way into the aquatic ecosystem through untreated effluents discharged after anthropogenic activities. These foams, by the mechanism of foam fractionation, also tend to enrich many organic and inorganic compounds into the foam phase. Enrichment might lead to precariously high concentrations of surface-active contaminants in the foam phase, which would otherwise be within acceptable levels in bulk lake water. Thus, foam not only has surfactants but also has other enriched chemical compounds in it.

This work aims to identify those compounds in foam, focusing on sewage-fed Bellandur lake in India, which has been infamous for foaming for the past decade and understand their environmental implications. Bellandur Lake has anionic surfactant concentrations reaching up to 20 mg/l and surface tension as low as 45 mN/m. The Lake is eutrophied, with chlorophycean algae concentration reaching up to 13.8×107 cells/mL of Lake water. The scope of this study is as follows:

  • to assign relative flux to surfactants from various sources and identify the most significant contributor to foaming events;
  • to estimate the relative difference in concentrations of contaminants in bulk liquid and foam phase and predict the possibility of an impending threat, if any.

This study thus provides an opportunity for a better understanding of the foaming pattern, which is essential to prevent the occurrence of such foaming events in future.

How to cite: Das, R., Hoysall, C., and Rao, L.: Foam Composition and Surfactant Sources in an Urban Foaming Lake: A Comprehensive Analysis, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-196, https://doi.org/10.5194/egusphere-egu23-196, 2023.

EGU23-813 | Posters on site | HS8.1.1 | Highlight

Identifying wastewater pollutants from pharmaceutical residues and xenobiotic contaminants in Indian secondary cities 

Shubham Kumar, Indra Mani Tripathi, and Pranab Kumar Mohapatra

Emerging contaminants are becoming more prevalent in the environment. The consequences of emerging contaminants on the urban environment and living being's health are poorly understood by society. Pharmaceutical compound removal is not considered in designing a conventional sewage treatment facility. Instead, they were primarily concerned with organic and bacterial removal. Molecules containing xenobiotics whose physicochemical characteristics, such as small molecular size, water solubility, ionizability and volatility, make it challenging to identify, quantify, and degrade these complex chemicals. In the present study, we will take samples from Surface Water (SW) and Wastewater Treatment Plants (WTP) in the fast-growing Indian secondary cities (Bhopal, Bhuj and Kozhikode). We use analytical methods, including High-Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC) coupled with Mass Spectrometry (MS) to identify these compounds. The mentioned techniques have the potential to characterise complex environmental chemicals at low concentrations. In addition, Wetlands Construction can be an alternative and affordable technology for emerging compound treatment that performs satisfactorily for a variety of sewage types, including domestic sewage and wastewater. Our study identifies the contaminants present in the environment and the most popular analytical techniques for identifying and quantifying these compounds. We also present some potential solutions for the treatment of compounds by fusing several other technologies. This shows that in order to lessen or stop the deposition of these compounds into the environment, sewage treatment technologies need to be investigated and combined.

How to cite: Kumar, S., Tripathi, I. M., and Mohapatra, P. K.: Identifying wastewater pollutants from pharmaceutical residues and xenobiotic contaminants in Indian secondary cities, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-813, https://doi.org/10.5194/egusphere-egu23-813, 2023.

With the increasing research on particles and biocolloids in terrestrial and aquatic systems, the transport and deposition of particles and biocolloids in porous media has become an important research topic. Based on the transport and deposition experiments of heavy metal pollutants and suspended-colloidal particles (SPs) in porous media, a nonlinear attachment-detachment model with adsorption hysteresis is proposed, which uses an adsorption function and scanning desorption isotherms to model the deposition effect of SPs. The reaction rate constant related to hysteretic characteristics essentially reflects the nonequilibrium hydrodynamic process during the transport of SPs. Static deposition tests and column experiments with pulse injection are used to calibrate the transport parameters. Column penetration experiments are performed under variable injection concentrations and seepage velocities. The results show that there is good agreement between simulated and experimental breakthrough curves (BTCs).

This model shows that increasing or decreasing the seepage velocity results in substantial changes in the penetration concentration of SPs, which is closely related to the adsorption hysteresis and the deposition dynamics of SPs. When the injection concentration is increased, the effluent concentration clearly increases, which reflects a nonlinear deposition process. In contrast, with a decrease in the injection concentration, the release effect of the already deposited SPs prolongs the penetration process, which is also related to the hysteresis. Previously proposed linear attachment-detachment models probably result in an overestimation of the adsorption capacity of porous media.

How to cite: Bai, B., Wu, H., and Bai, F.: A nonlinear attachment-detachment model with adsorption hysteresis for suspension-colloidal transport, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1194, https://doi.org/10.5194/egusphere-egu23-1194, 2023.

The wide application of industrial and consumer product leads to the ubiquitous presence of PFOA (an anionic surfactant) in natural environments. PFOA could interact with microplastics (one emerging pollutants abundant in environments) and the transport of both PFOA and microplastics thus might be altered. The cotransport behaviors of PFOA with micron-sized plastic particles (MPs) with different surface charge (both negative and positive surface charge) in porous media in both 10 and 50 mM NaCl solutions were investigated in present study. Both types of MPs (negatively charged carboxylate-modified MPs (CMPs) and positively charged amine-modified MPs (AMPs)) could adsorb PFOA onto MPs surfaces which decreased PFOA transport with MPs co-present in suspensions under both solution conditions examined. PFOA had diverse impact on the transport behaviors of CMPs and AMPs. Specifically, PFOA decreased the transport of CMPs, while increased the transport of AMPs when PFOA was copresent in suspensions. The mechanisms driving to the changed transport of two types of MPs induced by PFOA were found to be different. The decreased electrostatic repulsion of CMPs due to the adsorption of PFOA onto CMPs surfaces led to the decreased transport of CMPs when PFOA was copresent. The increased electrostatic repulsion due to the adsorption of PFOA onto AMPs surfaces as well as the steric repulsion induced by suspended PFOA caused the enhanced AMPs transport with PFOA in solutions. The results of this study show that when PFOA and microplastics are copresent in natural environments, their interaction with each other will alter their transport behaviors in porous media, and the alteration is highly correlated with the surface charge of MPs.

How to cite: Rong, H. and Tong, M.: Cotransport of PFOA with Different Electrically Charged Plastic Particles in Saturated Porous Media, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1651, https://doi.org/10.5194/egusphere-egu23-1651, 2023.

The release of microplastics (MPs) especially those with sizes less than 10 μm from effluent of wastewater treatment plants (WWTPs) is one of the major sources of plastics into aquatic environment. To reduce the discharge of MPs into environment, it is essential to further enhance their removal efficiencies in WWTPs. In present study, to boost the removal performance of MPs in sand filtration systems (units that commonly employed in WWTPs to remove colloidal pollutants), six types of biochar fabricated from three raw biomass materials (i.e. lignin, cellulose, and woodchips) at two pyrolysis temperatures (400 °C and 700 °C) was respectively amended into sand columns as thin permeable layer. We found that adding all six types of biochar into sand columns as thin permeable layer could greatly improve the retention of MPs with the diameter of 1 μm under either slow (4 m/d) or fast flow rates (160 m/d) due to the high adsorption capability of biochar. Woodchip-derived biochar exhibited the highest MPs retention performance, which was followed by cellulose-derived biochar and then lignin-derived biochar. Moreover, for biochar derived from three raw biomasses, increasing pyrolysis temperature could improve MPs retention performance. The direct observation of real-time plastics retention processes on different types of biochar via a visible flow chamber showed that woodchip-derived biochar especially that fabricated at 700 °C exhibited more MPs trapping processes relative to lignin and cellulose-derived biochar due to their more complex surface morphology. Thus, the highest MPs retention performance was achieved in sand columns with amendment by 1 wt% woodchip-derived biochar fabricated at 700 °C. More importantly, we found that for these modified sand filtration column systems, complete MPs removal could be achieved in real river water and actual sewage water, in multiple filtration cycles, longtime filtration process (100 pore volumes injection) as well as with interval flow conditions. Moreover, biochar could be regenerated and reused as thin permeable layer to effectively remove MPs. The results of this study clearly showed that biochar especially woodchip-derived biochar fabricated at 700 °C had the potential to immobilize MPs especially those with small sizes in WWTPs.

How to cite: Hsieh, L. and Tong, M.: Addition of biochar as thin preamble layer into sand filtration columns could improve the microplastics removal from water, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1771, https://doi.org/10.5194/egusphere-egu23-1771, 2023.

EGU23-2118 | Posters on site | HS8.1.1

Transport of thiophanate methyl in porous media in the presence of titanium dioxidenanoparticles 

Constantinos V. Chrysikopoulos, Anthi S. Stefanarou, Vasileios E. Katzourakis, and Anastasios A. Malandrakis

This study investigates the transport of pesticide thiophanate methyl (TM) as well as the co-transport of TM and titanium dioxide (TiO2) nanoparticles in a water saturated column packed with quartz sand under various water conditions. Several ionic strengths (Is) (1, 10, 50 and 100 mM) and pH (3, 5, 7, 10) values were examined. The results from the transport experiments  were fitted and analyzed with the use of the ColloidFit software, while the results from cotransport experiments were fitted with a modified mathematical model of Katzourakis and Chrysikopoulos (2015). The results suggested that the lowest mass recovery rate was for the co-transport experiments with the addition of NaCl. It was shown that TM has a weak affinity for sand but a relatively strong affinity for TiO2 at high Is and acidic pH. Furthermore, salinity was shown to have significant effects on TM removal.

How to cite: Chrysikopoulos, C. V., Stefanarou, A. S., Katzourakis, V. E., and Malandrakis, A. A.: Transport of thiophanate methyl in porous media in the presence of titanium dioxidenanoparticles, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2118, https://doi.org/10.5194/egusphere-egu23-2118, 2023.

EGU23-2570 | ECS | Orals | HS8.1.1

Zinc nanoparticles combat boscalid-resistance in Alternaria alternata 

Anastasios Malandrakis, Nektarios Kavroulakis, and Constantinos Chrysikopoulos

The potential of ZnO nanoparticles (NPs) to control Alternaria alternata isolates resistant to the succinate dehydrogenase inhibitor (SDHI) boscalid was evaluated both in vitro and in vivo. ZnONPs could effectively inhibit mycelial growth and suppress disease symptoms in both boscalid sensitive (BOSC-S) and resistant (BOSC-R) isolates. A high synergistic effect against BOSC-S and BOSC-R isolates was observed when ZnO-NPs was combined with boscalid both in vitro and when applied in artificially inoculated tomato fruit. The positive correlation between nanoparticles and their ionic counterpart ZnSO4 and the neutralization of the ZnO-NPs fungitoxic action in the presence of EDTA suggested that zinc ion release is the most probable fungitoxic mechanism of ZnO-NPs. The disruption of cellular ion homeostasis mechanisms by zinc NPs could account for the enhanced effectiveness of ZnO-NPs against A. alternata  compared to ZnSO4. ATP-dependent ion efflux and ROS production could contribute to the fungitoxic action of ZnO-NPs as indicated by bioassays with ATP- and antioxidant-inhibitors. Boscalid acting as a “capping” agent for ZnO-NPs, significantly reducing NPs mean size, probably accounted for the synergy observed against BOSC-S and BOSC-R isolates. Concluding, ZnO-NPs are effective against A. alternata both alone or in mixtures with boscalid, and can be used as an effective, eco-compatible anti-resistance tool for reducing the environmental footprint of synthetic fungicides.

How to cite: Malandrakis, A., Kavroulakis, N., and Chrysikopoulos, C.: Zinc nanoparticles combat boscalid-resistance in Alternaria alternata, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2570, https://doi.org/10.5194/egusphere-egu23-2570, 2023.

EGU23-2785 | ECS | Orals | HS8.1.1

Thermal impact of underground car parks on groundwater 

Maximilian Noethen, Hannes Hemmerle, Susanne Benz, Kathrin Menberg, Jannis Epting, Philipp Blum, and Peter Bayer

In addition to the continuous increase of groundwater temperatures due to global warming, heat losses from infrastructure, (underground) buildings and geothermal use lead to thermal anomalies on regional to local scales. Often, these local heat accumulations (hot spots) of groundwater temperatures are associated with underground car parks (UCP). They represent sizeable infrastructures that are typical for densely built-up areas and are numerous in many cities. Unlike regular basements, they often reach beneath the groundwater table and heat up due to frequent traffic. They therefore act as heat sources for groundwater. By analysing long-time data from 31 sites in Germany, Austria, and Switzerland, we discovered seasonally varying heat flux intensities and even directions. While all UCPs heat the groundwater during the warm period, most UCPs cool the groundwater in the cold period. Only few act as continuous heat source all year round. We also discuss characteristics and their influence on the temperature such as the type of use (public/private) and the depth of the UCP. Furthermore, we present the results of a spatial analysis of heat fluxes and flows from over 5000 UCPs in Berlin, Germany. By discussing the range of heat fluxes and the hydrogeological conditions that lead to regional differences, we demonstrate the role of UCPs for subsurface urban warming. The results show that about 40 % of Berlin’s total heat flow from UCPs occurs in the “Mitte” district, where the density of UCPs is highest and the distance to the groundwater table is typically below 4 m. Finally, the knowledge gained about subsurface heat sources can help improve urban thermal groundwater management and highlights the potential for recovering waste heat from UCPs through geothermal applications.

How to cite: Noethen, M., Hemmerle, H., Benz, S., Menberg, K., Epting, J., Blum, P., and Bayer, P.: Thermal impact of underground car parks on groundwater, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2785, https://doi.org/10.5194/egusphere-egu23-2785, 2023.

EGU23-3082 | ECS | Posters on site | HS8.1.1

Numerical modeling of flow in a phosphogypsum stack. Case of salt-marshes, Huelva, SW Spain. 

Franco Coscia, Enric Vázquez-Suñè, and Estanislao Pujades

Phosphogypsum is a waste that results when fertilizer is obtained from phosphate through a wet chemical process. Phosphogypsum waste can entail negative consequences for the environment and human health since it is enriched in radionuclides from U-decay series and metal impurities. Phosphogypsum wastes are commonly accumulated in large stockpiles that are exposed to weathering processes. These stockpiles are located near the plants where phosphate is processed, which are usually located in coastal areas. This is the case of a phosphogypsum stack on the western side of the Tinto River estuary (Huelva, SW Spain), where the piles were directly settled on the marshland without using any isolation from 1968 to 2010. Here, in addition to the potential environmental impacts, the effect of the phosphogypsum wastes on human health are a source of concern since the piles are located near the city of Huelva (Spain). In this context, it is of paramount importance to assess the phosphogypsum leachate percolation into underlaid aquifer systems and the release of pollutants to the Tinto River.

This investigation aims at building a complex coupled hydro-chemical numerical model accounting with variable density to quantify how the pollutants are released to the environment. The first step has consisted in developing the flow numerical model that has been calibrated by fitting the piezometric head oscillations as a result of recharge processes and sea tide oscillations. The good fitting obtained during the calibration process (normalized RMS when comparing simulated and observed piezometric heads is less than the 10%) allows affirming that the estimated hydraulic parameters are accurate, and are consistent with the literature reviewed. Furthermore, the numerically calculated mass balance is consistent with the conceptually estimated one, the differences were as expected. Thus, the model allows simulating the flow processes and modelling predictive scenarios. The next steps will consist in implementing variable density and hydro-chemical, and possibly, hydromechanical processes.

This study, which uses numerical modelling, is intended to be useful for future work related to restoration measures and provides new insights into the water balance along with the complex processes occurring at the site.

How to cite: Coscia, F., Vázquez-Suñè, E., and Pujades, E.: Numerical modeling of flow in a phosphogypsum stack. Case of salt-marshes, Huelva, SW Spain., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3082, https://doi.org/10.5194/egusphere-egu23-3082, 2023.

Groundwater located in peri-urban areas may be impacted by many pollutants from different types of point or diffuse sources. About 40% of Brazil's waste is disposed of inappropriately in open dumps and constitutes a risk of contamination for aquifers. In the metropolitan region of the city of Salvador in northeastern Brazil, approximately 9,800 tons of solid waste are generated daily. This research aimed to delineate areas for the implementation of landfills and protection of peri-urban groundwater in Salvador and other catchments in northeastern Brazil. An integration of Boolean and fuzzy logic was performed using GIS, while the Analytic Hierarchy Process was used in a Multi Criteria Decision Analysis technique to generate the weights of the factors and criteria for the fuzzy model. From this methodology, two preliminary models were generated, one using the Boolean logic and the other the fuzzy logic. The first used restrictive criteria established by Brazilian legislation applied to fifteen factors/themes. In the second model, non-restrictive criteria were applied to eleven factors/themes based on technical knowledge and literature. The integration of the maps and the crossing of the models demonstrates that 6% of the studied areas are classified as highly adequate; 16% as adequate; 8% not suitable; and 70% are areas with total restrictions for locations of landfills and protection of aquifers.

How to cite: Leal, L., Purificação, C., Klammler, H., and Hatfield, K.: GIS‐based multi-criteria decision analysis for suitable locations of landfills and protection of peri-urban groundwater catchments: a case study in northeastern Brazil, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4754, https://doi.org/10.5194/egusphere-egu23-4754, 2023.

EGU23-5588 | ECS | Posters on site | HS8.1.1 | Highlight

What are the driving factors affecting urban groundwater quality? A multi-tracer approach for the assessment of Vienna’s shallow aquifers 

Eva Kaminsky, Constanze Englisch, Christian Griebler, Cornelia Steiner, Gregor Götzl, Kay Knoeller, Hans Sandén, Gregor Laaha, and Christine Stumpp

Urban shallow groundwater is highly impacted in terms of hydrogeology and water quality by anthropogenic activities and infrastructure, such as heating and cooling, surface sealing, leaking sewage pipes, and underground buildings. For a sustainable management of urban water resources, a better understanding of biogeochemical processes and its dynamics on a spatial and temporal scale in the urban subsurface is needed. So far, data sets including a critical minimum number of key parameters and an appropriate resolution in space and time have often been missing. Here, we introduce a multi-tracer approach applied to assess the shallow aquifers in Vienna. Water samples were collected twice, in autumn 2021 and spring 2022, respectively, from 150 groundwater wells in the city limits of Vienna. A comprehensive set of parameters (e.g. major ions, nutrients, heavy metals, water and nitrate stable isotopes) were analyzed to evaluate the spatial and seasonal variations in water origin and quality. Statistical analysis revealed that driving factors influencing groundwater quality include aquifer properties, interactions between groundwater-surface water, and redox conditions. A combined interpretation of conservative tracers indicated zones influenced by surface water - groundwater interactions that also influenced the water chemistry. Microbial anaerobic processes govern groundwater quality. In particular, contamination of nitrate from septic water and manure is locally reduced by denitrification, as proven by compound-specific isotope analysis, improving water quality. At the same time, other anaerobic processes, such as iron and manganese reduction, sulfate reduction, and methanogenesis deteriorate water quality. Finally, groundwater temperatures, up to 27°C, were observed close to urban underground infrastructure, hinting at subsurface buildings and surface sealing as stressors in shallow groundwater. In conclusion, our high resolution spatial sampling with the large set of parameters will not only allow a better understanding of groundwater quality dynamics, but also allows to evaluate effects to groundwater biodiversity and develop predictive mathematical models.

How to cite: Kaminsky, E., Englisch, C., Griebler, C., Steiner, C., Götzl, G., Knoeller, K., Sandén, H., Laaha, G., and Stumpp, C.: What are the driving factors affecting urban groundwater quality? A multi-tracer approach for the assessment of Vienna’s shallow aquifers, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5588, https://doi.org/10.5194/egusphere-egu23-5588, 2023.

EGU23-7356 | Orals | HS8.1.1

A holistic view of water sources in Kyiv, Ukraine using tap water, surface water, groundwater, and precipitation hydrogen (𝛿2H) and oxygen (𝛿18O) stable isotope ratios 

Andrea Erhardt, Elizabeth Avery, Olena Samonina, Lidiia Kryshtop, Iryna Vyshenska, and Alan Fryar

The water supply for Kyiv (Ukraine) is a seasonally and spatially variable mixture of both ground and surface water. This water supply is vulnerable to the effects of climate change, pollution, and geopolitical conflict. Climate change has resulted in changing precipitation patterns, potentially altering the balance between ground and surface water utilization. Additionally, the ongoing conflict makes a holistic understanding of water resources and pathways critical for water management. This study uses water stable isotopes as tracers for water sources and the importance of different reservoirs in water management.

For this study tap water, surface water, groundwater, and precipitation were collected over 14 months (2019-2020) in Kyiv and nearby Boryspil, Brovary, and Boyarka and measured for hydrogen (𝛿2H) and oxygen (𝛿18O) stable isotope ratios. Precipitation data was used to capture seasonal variability in storm trajectories and create a meteoric water line. These results were then compared to surface, ground, and tap water to capture water sources and residence times.

The stable isotope values from the tap water for each district show a general seasonal trend in water sources, with more groundwater used in the supply in the winter for most districts. Spatially, groundwater use increases from south to north in the left-bank districts in Kyiv city and groundwater use generally decreases from south to north in the right-bank districts. As precipitation patterns shift and temperatures increase, the reliance on particular water sources may need to shift as well.

 Overall, 𝛿2H and 𝛿18O data provide a baseline expectancy for current water use throughout the year and, from this, deviations can be assessed early. A holistic view of the water system will be critical to assess changes due to infrastructure damage and/or other impact on water management in the Kyiv region.

How to cite: Erhardt, A., Avery, E., Samonina, O., Kryshtop, L., Vyshenska, I., and Fryar, A.: A holistic view of water sources in Kyiv, Ukraine using tap water, surface water, groundwater, and precipitation hydrogen (𝛿2H) and oxygen (𝛿18O) stable isotope ratios, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7356, https://doi.org/10.5194/egusphere-egu23-7356, 2023.

Abandoned mines can play a new role in renewable energy production and storage in combination with fifth-generation heating and cooling networks. Obviously, the underground potential must be matched with the uses/productions of heat and cold by surface activities. Therefore, this will be considered here only in highly urbanized areas or in economic and industrial areas.

Flooded abandoned mines form highly heterogeneous aquifers that are artificially and locally highly permeable around former underground works (i.e., tunnels, galleries, mined extraction zones, wells, shafts). Thermal energy storage (ATES) systems, using heat pumps and an open loop with a groundwater pumping and re-injection doublet, are thus challenging and uncertain in such a variable underground environment. Hot water is pumped in the deepest parts of the open network, and cold water can be re-injected in the shallower parts (i.e. in shallower galleries or fractured rocks). A seasonal inversion could be planned for cooling the buildings during the summer season. However, the true geometry of the interconnected network made of old open galleries and shafts can be highly complex and partially unknown. Indeed, high-velocity water flow and heat transport are expected in this network inducing potentially a full or partial bypass of the fractured and porous rock massif.

A hydrogeological characterization of the old mined zones for detailed simulations of the groundwater flow and associated heat transport is thus a needed step allowing to assess the actual feasibility of a given project. The simulated short-, mid-, and long-term temperature evolution in pumping and injection zones will consist of key information for designing and dimensioning the whole geothermal project and assessing future efficiency and impact. Depending on the degree of precision required, which is dependent on the level of reduction of uncertainties associated with the geothermal project, the hydrogeological baseline issues can be very significant, challenging scientists in different areas of quantitative hydrogeology:

  • conceptualization in a simple model of the often unknown complexity/heterogeneity of the galleries network conjugated to those of the mined geological formations;
  • simulation of temperature-dependent variable-density groundwater flow and coupled heat transport;
  • combining high-velocity ‘pipe-like’ water flows (in the shafts and galleries) and porous/fractured groundwater flow (in the rock matrix);
  • simulation of different transient scenarios to assess evolutions in the long term.

As an illustration, a simplified but realistic situation is simulated showing the influence of the highly different heat/cold transport in the galleries and shafts, compared to the propagation in the porous/fractured rocks. Indeed, the different temperature evolutions allow anticipating the temperature changes affecting the future (short-, mid-, and long-term) efficiency of a geothermal system as well as possible environmental impacts.

Real cases in relation to future projects should ideally be simulated using the most detailed approaches, with true data. Those baseline hydrogeological data are not easy to obtain but they are the guarantee of reliable predictions and therefore that the financial risk is reasonable.

Dassargues A., 2018. Hydrogeology: groundwater science and engineering, 472p. Taylor & Francis CRC press, Boca Raton.

How to cite: Dassargues, A. and Orban, P.: Hydrogeological baselines for geothermal energy and heat storage in old flooded coal mines in urban areas, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7715, https://doi.org/10.5194/egusphere-egu23-7715, 2023.

EGU23-7878 | Orals | HS8.1.1 | Highlight

Potential and limitations of silica encapsulated DNA particles for hydro(geo)logy 

Jan Willem Foppen and Thom Bogaard

Artificial DNA as a tracer in environmental applications has received increased attention in environmental science. In the last few years, we have been looking at the transport of silica encapsulated DNA particles (SiDNA), which we injected instantaneously or as a function of time in various saturated groundwater and surface water laboratory set-ups. These included batches, columns, sand tanks, open pipes, trenches, flumes, etc. The overarching aim of all these experiments was to understand SiDNA transport behaviour, to quantify the mass balance and to assess tracer-like capabilities of SiDNA. Our work indicated that in most applications, the shape of the breakthrough curve in terms of time to rise and time to peak were similar to the breakthrough curve of a conservative tracer. Specifically, SiDNA could be used to quantify dispersion in surface water transport, and to determine aquifer parameters, like hydraulic conductivity and porosity in multi-tracer experiments. However, this was accompanied by some uncertainty as in most applications, injected mass recoveries were less than 100% due to losses as a result of settling, river bed interactions, interactions with particulate matter (in surface water applications), straining, kinetic attachment and detachment (in groundwater applications). 
We conclude that SiDNA can be used when mass balance issues are relatively unimportant, for instance in case of complex flow path analyses or source tracking applications, whereby encapsulated artificial DNA with different DNA strands can be injected in several locations or can be added to the source. Currently, we think large scale field applications of SiDNA are still limited, due to required specific knowledge and analytical infrastructure, relatively high costs and limited SiDNA production scale. Once these issues are tackled, a truly unique multi-tracer will enrich the toolbox of hydrologists.

How to cite: Foppen, J. W. and Bogaard, T.: Potential and limitations of silica encapsulated DNA particles for hydro(geo)logy, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7878, https://doi.org/10.5194/egusphere-egu23-7878, 2023.

EGU23-8241 * | ECS | Orals | HS8.1.1 | Highlight

300 years of organic pollution recorded in an urban speleothem (Paris, France) 

Julia Garagnon, Yves Perrette, Emmanuel Naffrechoux, and Edwige Pons-Branchu

The preservation of water resources and the limitation of pollution are an environmental central issue in the current intense anthropization context. Considered as sensitive recorders of past changes, speleothems offer an under investigated natural archive for the reconstruction of water quality. Urban speleothems have recently been used to show the impact of urbanization over the water quality using inorganic trace elements. Speleothems thus represent a promising archive of water quality on short and long-time scales. However, they have never been used to trace organic pollution. Within the organic and anthropogenic proxies, polycyclic aromatic hydrocarbons (PAHs) are commonly used in water quality analysis. These persistent organic pollutants (POPs) are mainly due to anthropogenic emissions. The use of speleothem to trace the variations in quantity and quality of organic matter, including organic pollutant as PAHs, over the last centuries, is unprecedented.

For this purpose, high resolution (10 µm) solid phase UV fluorescence imaging analyses were crossed with chemical analyses (PAHs, Non Purgeable Organic Carbon (NPOC)) carried out on low weight samples (a few mg to g) from a Parisian aqueduct flowstone. Solid-phase fluorescence imaging, although poorly applied yet to speleothems, is a non-destructive technique. To obtain quantitative information, solid phase spectroscopy is coupled with liquid phase compound analysis and NPOC analysis. Due to their low concentration, the analysis of PAHs required a long development phase. The protocol consists of an extraction and analysis process using high performance liquid chromatography coupled with a fluorescence detector. The first results reveal the presence of PAHs for 300 years in runoff water with an increase, in particular in heavy molecular weight PAHs, over the last two decades. These data will be crossed with modelled imaging of quantitative variations in organic matter. This work opens the way to a better long term understanding of the impact of anthropization on transfer of pollutants in subsurface waters.

How to cite: Garagnon, J., Perrette, Y., Naffrechoux, E., and Pons-Branchu, E.: 300 years of organic pollution recorded in an urban speleothem (Paris, France), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8241, https://doi.org/10.5194/egusphere-egu23-8241, 2023.

Nanoscience and nanotechnology have revolutionized many sectors of the industry with the development of novel materials and technologies. With the increasing use of nanomaterials in products and applications, the presence of nanoparticles in the environment, such as in soil, sediments, water, air, and biota, is inevitable. Understanding of the physical and chemical processes and environmental conditions that govern the fate and behavior of nanomaterials in the environment is essential to strengthen the environmental and human health security. This study discusses the role of physical and chemical processes and environmental conditions on the fate, transport, behavior, transformation, and toxicity of metal based nanoparticles and their environmental impacts, with a focus on terrestrial and aquatic systems, as well as plants and microorganisms. Research on the interactions of nanomaterials with the environment and biological systems will allow the development of models contributing to advancing knowledge on the behavior and fate of nanoparticles in the environment and assessing their potential risk in the environment.

How to cite: Darnault, C.: Nanomaterial Interactions with the Environment and Biological Systems: Implications for Soil, Water, Plants, and Microorganisms, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10830, https://doi.org/10.5194/egusphere-egu23-10830, 2023.

EGU23-10883 | Posters on site | HS8.1.1

The influence of microplastics on the dry end of the soil-water retention curve 

Hannes Laermanns, Markus Rolf, Susanne Forche, Elena Castrucci, Alexander Stelzer, and Christina Bogner

Most studies focus on the detection of microplastic particles in different compartments of the environment. While impacts of microplastics on aquatic systems have already a wide acceptance in public, the research on microplastics in terrestrial systems is quite young. Our study aims to decipher the consequences of microplastics on the soil-water retention curve beyond the wilting point. Using a dew point WP4C hygrometer, we measured water retention curves of loess and sand samples with added microplastics, namely amorphous biopolymer, polystyrene in two sizes and three different types of UV-aged particles. All the different microplastics were added in concentrations of 0.1 wt.%, 0.5 wt.%, and 4.5 mg/kg. Reference samples without microplastics were prepared as well. For the analysis, we fitted the Webb model and calculated the water content at the wilting point and the slope of the soil-water retention curve. Our preliminary results did not show any significant differences between the different microplastics and their concentrations, however, the lowest slope and highest water content at pF 4.2 were observed in the samples without microplastics. Furthermore, the results indicated a greater variability with increasing size of microplastic particles.

How to cite: Laermanns, H., Rolf, M., Forche, S., Castrucci, E., Stelzer, A., and Bogner, C.: The influence of microplastics on the dry end of the soil-water retention curve, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10883, https://doi.org/10.5194/egusphere-egu23-10883, 2023.

EGU23-11717 | ECS | Posters on site | HS8.1.1

Surrogate-based implementation of sewer network structures into numerical heat transport models: First results of the Basel-City case study 

Martin Binder, Felicia Kossek, Christian Engelmann, and Jannis Epting

Adequate management strategies are critically required to increase the resilience and long-term availability of groundwater resources in the light of progressive climate change and accelerating urbanization. Here, robustly parameterized numerical models, designed for simulating water flow as well as solute and heat transport processes in the hydrogeological subsurface, are powerful and widely established tools supporting decision making and planning.

Among other applications related to more general quantity- and quality-related questions, these numerical tools can be also used, e.g., for investigating the current thermal state of the subsurface and occurring changes due to artificial and natural influences. Models designed for this very specific task should include at least all major artificial objects (e.g., underground car parks, tunnels, buildings, sewer networks) which thermally contribute to the overall groundwater heat regime. For instance, the heat exchange between the subsurface and sewer systems may significantly contribute to the subsurface urban heat island effect and should, therefore, be implemented. However, fully three-dimensional implementations of sewer networks (typically with hundreds of kilometers of pipes) are mostly out of question when applying such numerical models, since it would be associated with large computational demands and increasing numerical instabilities.

To overcome this limitation, the focus of our ongoing research is to evaluate the suitability of an adaptive surrogate method to be coupled to existing numerical heat transport models. This method is based on linking expected thermal exchange rates between small subsurface objects (e.g., sewer pipes) and their surrounding area, which depend on site-specific parameters (e.g., surface-groundwater table distance, pipe dimensions, shapes and materials), with the spatial elements of an existing model mesh, e.g., as area-averaged heat sources or sinks. Numerical heat conduction simulations performed on pipe scale while employing seasonally changing ambient and sewer conditions point towards the importance of considering both stationary (such as materials) and transient input datasets (such as temperature fluctuations) in this linking process. The collection and pre-processing of both dataset types is performed in separate workflows employing standardized geographic information system (GIS) software. Based on these input datasets, heat flux calculations can be done either employing the numerical code itself (if the model code allows user-defined calculations) or, again, in a GIS-assisted step (in order to further reduce the computational demand during the runs of the numerical model).

The conceptual workflow, first results as well as expected advances and limitations of this surrogate approach will be critically discussed using the example of the well-documented heat transport case study of ‘Basel-City’. Among others, the aforementioned stationary and transient input datasets, and based on that, processed vertical heat fluxes will be presented for selected areas of the Swiss canton.

How to cite: Binder, M., Kossek, F., Engelmann, C., and Epting, J.: Surrogate-based implementation of sewer network structures into numerical heat transport models: First results of the Basel-City case study, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11717, https://doi.org/10.5194/egusphere-egu23-11717, 2023.

EGU23-12562 | ECS | Orals | HS8.1.1

Microplastics in sediment deposited along the Seine River after a major flood event (February 2021) 

Nadia Bouzid, Remi Bizeul, Anthony Foucher, Sophie Ayrault, Olivier Evrard, Rachid Dris, Bruno Tassin, and Jonnhy Gasperi

Depending on hydrodynamic conditions, river sediments act as a sinks or a sources of microplastics through deposition and remobilisation processes. During flood events, the increase of river flow leads to an increase in the resuspension of bottom sediments and bank erosion processes and favoring the microplastic transportation. Previous work conduced in the Seine river catchment in 2018 has shown that floods, which occur for only 15% of the annual time, contributed to 40% of the total microplastic flux. Therefore, at the end of a flood period, with the decreasing in water level, some flow regimes allow the deposition of contaminated sediments carried by the river on the banks.

This study presents the characterization and quantification of microplastics in ten samples lag deposits collected along the Seine river after the February 2021 flood event. Microplastics from 10 to 500 µm were analysed in replicate samples using two methods (FTIR microspectroscopy and Pyr-GC/MS). In order to characterize the origin of the sampled sedimentary deposits a fingerprinting approach based on the measurement of radionuclides activity (137Cs, 210Pbex and 7Be) was carried out. A mixing model was applied to discriminate old and recent sediments and their origin from the surface (e.g. soil erosion) or subsurface (e.g. bank erosion). High concentration levels of microplastics, ranging from 8,000 to 50,000 items/kg, were observed mainly characterised by FTIR microspectroscopy as PP, PE, PS and PVC. All the samples analysed show a similar size distribution with a majority of particles below 100 µm. PP is the most abundant polymer found. The quantification by Pyr-GC/MS provided masses consistent with microspectroscopy results ranging from 200 to 14,000 µg PP/kg of dry sediment.  An increase in microplastic contamination between the upstream and the downstream part of the Paris area was observed. In this study, the relationships between sediment characteristics and microplastic contamination could not be demonstrated. Further work is needed to verify whether a more marked relationship can be observed in major events where a clearer variation in sediment sources is observed between the upper and lower parts of the Paris area.

How to cite: Bouzid, N., Bizeul, R., Foucher, A., Ayrault, S., Evrard, O., Dris, R., Tassin, B., and Gasperi, J.: Microplastics in sediment deposited along the Seine River after a major flood event (February 2021), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12562, https://doi.org/10.5194/egusphere-egu23-12562, 2023.

EGU23-12881 | Posters on site | HS8.1.1

Processes affecting the behaviour of persistent, mobile, and toxic substances in a riverbank filtration system 

Estanislao Pujades, Carmen Sáez, Olha Nikolenko, Laura Scheiber, Arianna Bautista, Marinella Farré, and Anna Jurado

Riverbank filtration (RBF) consists in forcing surface water to infiltrate and flow through an aquifer by means of a pumping well located near a surface water body. RBF aims to take advantage of the filtration capacity of aquifers to improve the water quality by removing a wide range of pollutants, including contaminants of emerging concern, by combining of physical, chemical and biological processes. However, the efficacy of RBF for eliminating substances that are considered persistent, mobile, and toxic (PMT), or very persistent and very mobile (vPvM), is expected to be low due to the high mobility of these substances. PMT and vPvM compounds, which are accumulated in the water cycle, are harmful to humans and the environment. For this reason, the processes affecting PMT and vPvM substances during RBF processes deserve to be deeply investigated.

This study aims at investigating the processes affecting PMT and vPvM substances in a site that behaves similarly to a RBF system. The study site is located in Sant Adriá del Besòs (Barcelona, Spain), where a constant pumping to drain an underground parking lot forces the water from the Besòs river to infiltrate and travel up to 230 m through the aquifer. Groundwater samples were collected from the river, and a set of piezometers aligned along the groundwater flow line between the Besòs river, and the underground parking lot allowed monitoring of the water at different stages after its infiltration. The samples were analysed by liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) and PMT and vPvM were determined by a suspected screening approach.

This investigation provides new insights into the processes affecting PMT and vPvM substances and will have tremendous implications for determining groundwater quality in managed aquifer recharge contexts.

How to cite: Pujades, E., Sáez, C., Nikolenko, O., Scheiber, L., Bautista, A., Farré, M., and Jurado, A.: Processes affecting the behaviour of persistent, mobile, and toxic substances in a riverbank filtration system, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12881, https://doi.org/10.5194/egusphere-egu23-12881, 2023.

EGU23-12959 | Posters on site | HS8.1.1

Organic contaminants of emerging concern (OCECs) in urban aquifers affected by geothermal exploitations 

Anna Jurado, María Alejandra Villa, Marc Teixidó, Nicola Montemurro, Sandra Pérez, Jan Willem Foppen, and Estanislao Pujades

Water shortage is expected to exacerbate because of the increase pressure on water resources due to climate change and the growing population. It is deemed necessary to take advantage of all the available freshwater resources to cover the growing demand, especially in urban areas. However, urban aquifers are commonly contaminated by a wide range of organic contaminants of emerging concern (OCECs). OCECs, which comprise natural and synthetic compounds, are potentially hazardous to the environment and human health. Therefore, the processes controlling the behaviour of OCECs must be investigated to determine when and how the urban resources can be used safely and to design remediation strategies against them. The removal rate of OCECs depends on the temperature and redox conditions of groundwater that may be affected by anthropogenic activities like the exploitation of the geothermal potential of aquifers. The behaviour of some OCECs has been investigated in the context of managed aquifer recharge (MAR). However, the water range in MAR is lower than that expected around geothermal exploitations, and the behaviour of OCECs under similar conditions to that found around geothermal facilities should be evaluated. We have investigated the removal of 12 OCECs reported in the aquifers of Barcelona (Spain) by using batch experiments under different redox conditions and temperatures (25°C and 35°C). The results show that the removal rate of OCECs depends on the temperature, suggesting that the impact of geothermal exploitations must be considered when investigating the fate and evolution of OCECs in urban aquifers. Unexpectedly, it was observed that the removal rate could also decrease with the temperature, which may be related to the proliferation of different communities of bacteria depending on the temperature. Overall, this investigation supports the idea that it is possible to design geothermal facilities to promote the removal of OCECs.

How to cite: Jurado, A., Villa, M. A., Teixidó, M., Montemurro, N., Pérez, S., Foppen, J. W., and Pujades, E.: Organic contaminants of emerging concern (OCECs) in urban aquifers affected by geothermal exploitations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12959, https://doi.org/10.5194/egusphere-egu23-12959, 2023.

EGU23-14782 | ECS | Posters on site | HS8.1.1

Efficiency of activated sludge process for reduction of antibiotics from municipal wastewater  

Moushumi Hazra, Himanshu Joshi Joshi, and Bhanu P. Vellanki

With time, a lot of change in the nature of impurities, especially a surge in emerging contaminants in urban wastewater has been observed due to changing lifestyle, uncontrolled and mismanaged urban sprawl, increasing pollution and disease burden, and easy access to antibiotics. Conventional sewage treatment plants have thus faced challenges in treating emerging pollutants such as antibiotics, with variable success as reported in few studies.  Antibiotics are persistent in the environment and result into development of antimicrobial resistance. The concentration of antibiotics reportedly varies from µg/L to ng/L in raw/treated sewage which is generally dependent upon differences in environmental/social factors as well as treatment technology. The present study was conducted with the purpose of identifying the role of activated sludge process (ASP) in a standalone mode as well as in a hybrid mode duly integrated with upflow anaerobic sludge blanket reactor (UASB) in removal of antibiotics from the raw sewage. The antibiotics were analysed with a Liquid Chromatography Mass Spectrometer (LCMS), and the removal efficiencies were compared for both the treatment systems. The concentration of selected antibiotics in raw/treated sewage of the hybrid UASB-ASP varied in the range of 0.92-79025.9µg/L and 0.03-3439µg/L respectively. It was observed that the concentration of erythromycin was very less inspite of being used as a wide spectrum antibiotic against gram positive/gram-negative bacteria causing upper and lower respiratory diseases. An apparent reason could be that it is mainly metabolised by human liver and only 5% is excreted in active form. Also, low concentration of sulfamethoxazole and enrofloxacin were detected in the ranges 0.04-0.92µg/L and 0.03-0.94µg/L respectively in the raw/treated sewage. Notably, even these concentrations could also inhibit bacterial growth by altering microbial production of folic acid and induce antimicrobial resistance at sub lethal concentration. The removal efficiency for UASB-ASP for selected antibiotic was between 51.09% to 95.87% indicating an efficient reduction. Low concentration of sulfamethoxazole and enrofloxacin was observed within the range of 0.15 – 0.21 g/L and 0.007 – 0.01 µg/L in the raw/treated sewage of ASP. Negative removal (increased concentration in the treated sewage) was observed for erythromycin and ciprofloxacin, apparently because of resistance to degradation. The reduction of sulfamethoxazole, enrofloxacin, tetracycline was 27%, 52%, 65% where trimethoprim demonstrated maximum removal of 88% in ASP.  The hybrid UASB-ASP performed better than the standalone ASP with respect to reduction of all antibiotics, indicating that ASP can perform more efficiently when integrated with other technologies alongwith addition of a proper dosing of chlorination. Risk associated with the selected antibiotics from sewage treatment plant to the receiving environment (both water/soil) was quantified employing hazard quotient (HQ) using predicted no effect concentration (PNEC) values derived from literature. HQ for sulfamethoxazole was calculated to be above 1, and higher values were observed for trimethoprim (in the range of 589-628), and tetracycline (in the range of 405-722) indicating potential environmental concern for aquatic environment/soil, whichever may be of concern. No risk seemed to appear for indirect human exposure to enrofloxacin as indicated by the calculated values of HQ (0.004-0.02).

 

How to cite: Hazra, M., Joshi, H. J., and Vellanki, B. P.: Efficiency of activated sludge process for reduction of antibiotics from municipal wastewater , EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14782, https://doi.org/10.5194/egusphere-egu23-14782, 2023.

EGU23-16939 | Orals | HS8.1.1 | Highlight

Transport and Removal of Stormwater Vehicle-Related Contaminants in Laboratory Columns 

María Alejandra Cruz Bolaños, Jiaqui Xu, Jan Willem Foppen, and Marc Teixidó Planes

Stormwater runoff capture can provide means of flood control and augmentation of local water supplies. However, urban stormwater is considered a major transport vector of contaminants, primarily from vehicle-related sources. Unfortunately, conventional green infrastructures fail to consistently remove the contaminant dissolved fraction – in particular persistent, mobile, and toxic (PMT) organic pollutants. We investigated the transport and removal of stormwater vehicle-related trace organic contaminants, such as 1H-benzotriazole, N'N-diphenylguanidine, and hexamethoxymethylmelamine utilizing continuous-flow sand columns amended with granulated activated carbon (GAC) and wheat-straw produced biochar (WSP550). All the pollutants were subjected to nonequilibrium interactions in sand-only (control) and GAC/biochar-amended sand columns, with kinetic effects on transport. The Langmuir sorption kinetics model could well describe the observed breakthrough curves, which assumes the saturation of sorption sites that might occur in infiltration systems with DOM fouling. Furthermore, we found that GAC amendments can attenuate the contaminants significantly better with faster adsorption kinetics and higher sorption capacity than the biochar. Based on the optimized sorption parameters, we concluded that HMMM had the lowest affinity in both carbonaceous adsorbents. These column results corroborated observations from preliminary batch experiments. Based on the case study simulation, the amendments of pyrogenic carbonaceous adsorbents could improve vehicle-related organic contaminant removal and exhibit a service life of more than a decade in a green infrastructure. Overall, our research contributes to improving polar organic pollutant removal technologies in environmental applications.

How to cite: Cruz Bolaños, M. A., Xu, J., Foppen, J. W., and Teixidó Planes, M.: Transport and Removal of Stormwater Vehicle-Related Contaminants in Laboratory Columns, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16939, https://doi.org/10.5194/egusphere-egu23-16939, 2023.

EGU23-16985 | ECS | Posters virtual | HS8.1.1 | Highlight

Predicting bacterial transport through saturated porous media using an automated machine learning model 

Fengxian Chen, Bin Zhou, Liqiong Yang, Xijuan Chen, and Jie Zhuang

Escherichia coli, as an indicator of fecal contamination, can move from manure-amended soil to groundwater under rainfall or irrigation events. Predicting its vertical transport in the subsurface is essential for the development of engineering solutions to reduce the risk of microbiological contamination. In this study, we collected 302 datasets from 39 published papers addressing E. coli transport through saturated porous media and trained an automated machine learning model (H2O AutoML) to predict bacterial transport. Bacterial concentration, porous medium type, particle size, ionic strength, pore water velocity, and column length were used as input variables while the first-order attachment coefficient and spatial removal rate were set as target variables. The six input variables have low correlations with the target variables, namely, they cannot predict target variables independently. However, with the automated machine learning model, input variables can effectively predict the target variables. Among 20 candidate models, Gradient Boosting Machine showed the best performance. Among the six input variables, pore water velocity, ionic strength, particle size, and column length were more important than bacterial concentration and porous medium type. This method of using historical literature data to train automated machine learning models provides a new avenue for predicting the transport of other contaminants in the environment.

How to cite: Chen, F., Zhou, B., Yang, L., Chen, X., and Zhuang, J.: Predicting bacterial transport through saturated porous media using an automated machine learning model, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16985, https://doi.org/10.5194/egusphere-egu23-16985, 2023.

Previous studies with coarse-resolution global climate models (GCMs) have widely shown that extensive deforestation in the Amazon leads to a reduction in precipitation, with a potential irremediable loss of the rainforest past a critical threshold. However, precipitation in the Amazon region is of convective nature and thus has to be parameterized in coarse-resolution GCMs, limiting confidence in the results of such studies. To bypass this limitation, this study aims to investigate the impact of Amazon deforestation on precipitation in global climate simulations that can explicitly represent convection. The simulations are conducted with the ICON-Sapphire atmosphere-only model configuration run with a grid spacing of 5 km for two years. To understand the impacts of Amazon deforestation, we compare the results of a complete deforestation simulation with a control simulation. Results show no significant change in precipitation during the wet season and a slight decrease of precipitation during the dry season in the deforested simulation. Precipitation decreases due to decreased evapotranspiration are compensated by enhanced moisture convergence.

How to cite: Yoon, A.: The impact of Amazon deforestation on rain system using a storm-resolving global climate model, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1304, https://doi.org/10.5194/egusphere-egu23-1304, 2023.

The current crisis state of the planet, commonly called the Anthropocene, emerged as the result of the Great Acceleration in human consumption and environmental impact which followed the Second World War in the middle of the 20th c. There is growing evidence suggesting that similar acceleration dynamics, characterised by exponential growth in human environmental impact, occurred locally or regionally at earlier stages in human history. It is, however, difficult to identify, quantify, and confirm such cases without high-resolution, well-dated historical or paleoenvironmental data. In this presentation, I review three cases of well-documented Anthropocene-like accelerations, from Roman Anatolia, medieval Poland, and early modern Greece. In all of these cases, it was political consolidation, even if short-lived, as well as economic integration, that created the social tipping point triggering exponential acceleration of human environmental impact. All of these acceleration phases also collapsed once the underlying social dynamics was no longer present.

How to cite: Izdebski, A.: Social tipping points of Anthropocene acceleration dynamics in European history, from Roman times to the Little Ice Age, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3151, https://doi.org/10.5194/egusphere-egu23-3151, 2023.

Many aspects of anthropogenic global change, such as land cover change, biodiversity loss, and the intensification of agricultural production, threaten the natural biosphere. Implications of these specific aspects of environmental conditions are not immediately obvious, so it is hard to obtain a bigger picture of what these changes imply and distinguish beneficial from detrimental human impacts.  Here I describe a holistic approach that provides a bigger picture and use it to understand how the terrestrial biosphere can be sustained in the presence of increased human activities.  This approach focuses on the free energy generated by photosynthesis, the energy needed to sustain both the dissipative metabolic activity of ecosystems and human activities, with the generation rate being set by the physical constraints of the environment.  One can then distinguish two kinds of human impacts on the biosphere: detrimental effects caused by enhanced human consumption of this free energy, and empowering effects that allow for more photosynthetic activity and, therefore, more dissipative activity of the biosphere.  I use examples from the terrestrial biosphere to illustrate this view and global datasets to show how this can be estimated.  I then discuss how certain aspects of modern technology can enhance the free energy generation of the terrestrial biosphere, which can then safeguard its sustenance even as human activity increasingly shapes the functioning of the Earth system.

Note: Presentation is based on this manuscript (https://arxiv.org/abs/2210.09164), accepted for publication in the INSEE journal.

How to cite: Kleidon, A.: How to sustain the terrestrial biosphere in the Anthropocene? A thermodynamic Earth system perspective, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3251, https://doi.org/10.5194/egusphere-egu23-3251, 2023.

EGU23-3443 | Orals | CL3.2.6 | Highlight

Regional Climate Expected to Continue to Change Significantly After Net-Zero CO2 Emissions Reached 

Andrew H. MacDougall, Josie Mallett, David Hohn, and Nadine Mengis

The Zero Emissions Commitment (ZEC) is the expected temperature change following the cessation of anthropogenic emissions of climate altering gases and aerosols. Recent model intercomparison work has suggested that global average ZEC for CO2 is close to zero. However there has thus far been no effort to explore how temperature is expected to change at spatial scales smaller than the global average. Here we analyze the output of nine full complexity Earth System Models which carried out standardized ZEC experiments to quantify the ZEC from CO2. The models suggest that substantial temperature change following cessation of emissions of CO2 can be expected at large and regional spatial scales. Large scale patterns of change closely follow long established patterns seen during modern climate change, while at the regional scale patterns of change are far more complex and show little consistency between different models. Analysis of model output suggest that for most models these changes far exceed pre-industrial internal variability, suggesting either higher climate variability, continuing changes to climate dynamics or both. Thus it appears likely that at the regional scale, where climate change is directly experienced, climate disruption will not end even as global temperature stabilizes. Such indefinite continued climate changes will test the resilience of local ecosystem and human societies long after economic decarbonization is complete. Overall substantial regional changes in climate are expected following cessation of CO2 emissions but the pattern, magnitude and sign of these changes remains highly uncertain.

How to cite: MacDougall, A. H., Mallett, J., Hohn, D., and Mengis, N.: Regional Climate Expected to Continue to Change Significantly After Net-Zero CO2 Emissions Reached, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3443, https://doi.org/10.5194/egusphere-egu23-3443, 2023.

EGU23-5233 | Posters on site | CL3.2.6

Association for Trans-Eurasia Exchange and Silk-Road Civilization Development 

Likun Ai, Juzhi Hou, Haichao Xie, Yanbo Yu, and Fahu Chen

Spanning more than 6,400 kilometers across Eurasia, the Silk Road played a key role in facilitating exchanges in economy, culture, politics, and religions between East and West. The ancient Silk Road was one of the most important passages for trans-Eurasia exchange and human migrations, which could be traced back to 5000-4000 years before present. To deepen understanding of the effects of environmental changes in shaping the long-term trans-Eurasia exchanges and Silk Road civilization, the Trans-Eurasia Exchange and Silk-Road Civilization Development (ATES) was launched by a group of scientists with background of climate, hydrology, environment, archaeology in 2019. There are about 118 scientists from 10 countries that with different background have joined the ATES so far. ATES now has a President, and three coordinators in the secretariat, and all the alliance members are allocated to the 5 Working Groups (WG) based on their background and research interests. The main scientific issues for the ATES are: 1) Routes and driving forces of ancient human migrations across Eurasia in the Paleolithic; 2) Relationship between the food globalization, development of agro-pastoralism in Eurasia and human migration in the Neolithic; 3) Mechanisms of establishment, shift and demise of routes and key towns along the ancient Silk Road; 4) Effects of environmental changes on the rise and fall of the Silk Road civilization as to the trans-Eurasia exchanges in terms of economy, technology and culture. What does it tell us about the future of ongoing climate change? ATES aims to set an international platform to exchange multi-discipline knowledge and the latest research achievement on the ancient Silk Road, including exchanges of culture, science, and technology along the roads, perceptions of climate change, and socio-economic development in different historical periods along the Silk Road, and effects of environmental changes on the rise and fall of the Silk Road civilization.

ATES welcomes institutes and scientists worldwide to initiate and launch relevant research programs and projects with the ATES community. By establishing several joint research and education centers with partners, ATES facilitates and supports field observations, research, and capacity building. Training of Young Scientists is one of the main tasks for ATES capacity building, which includes the training workshops and field learnings organized by ATES and its partners. In order to strengthen the interaction of the ATES community, and to enhance the exchange of new achievements and insights of the interdisciplinary study on the evolution of trans-Eurasia exchanges and Silk Road civilization, the ATES Silk Road Civilization Forum invites a world-renowned scientist to give a special lecture on the focused topic every 3 months. ATES will organize parallel sessions and side meetings in the big events such as AGU, EGU, Conference of the Parties of the UNFCCC, UNCBD, ANSO conference, et al. ATES partners and other institutes are welcome to join in organizing the above meetings.

How to cite: Ai, L., Hou, J., Xie, H., Yu, Y., and Chen, F.: Association for Trans-Eurasia Exchange and Silk-Road Civilization Development, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5233, https://doi.org/10.5194/egusphere-egu23-5233, 2023.

EGU23-5722 | ECS | Orals | CL3.2.6 | Highlight

Recurrent droughts increase risk of cascading tipping events by outpacing adaptive capacities in the Amazon rainforest 

Nico Wunderling, Arie Staal, Frederik Wolf, Boris Sakschewski, Marina Hirota, Obbe A. Tuinenburg, Jonathan F. Donges, Henrique M.J. Barbosa, and Ricarda Winkelmann

Since the foundational paper by Lenton et al. (2008, PNAS), tipping elements in the climate system have attracted great attention within the scientific community and beyond. One of the most important tipping elements is the Amazon rainforest. Under ongoing global warming, it is suspected that extreme droughts such as those in 2005 and 2010 occur significantly more often, up to nine out of ten years from the mid to late 21st century onwards (e.g. Cox et al., 2008, Nature; Cook et al., 2020, Earth’s Future).

In this work, we quantify how climates ranging from normal rainfall conditions to extreme droughts may generate cascading tipping events through the coupled forest-climate system. For that purpose, we make use of methods from nonlinear dynamical systems theory and complex networks to create a conceptual model of the Amazon rainforest, which is dependent on itself through atmospheric moisture recycling.

We reveal that, even when the rainforest is adapted to past local conditions of rainfall and evaporation, parts of the rainforest may still tip when droughts intensify. We uncover that forest-induced moisture recycling exacerbates tipping events by causing tipping cascades that make up to one-third (mean+-s.d. = 35.9+-4.9%) of all tipping events. Our results imply that if the speed of climate change might exceed the adaptation capacity of the forest, knock-on effects through moisture recycling impede further adaptation to climate change.

Further, we use a network analysis method to compare the four main terrestrial moisture recycling hubs: the Amazon Basin, the Congo Rainforest, South Asia and the Indonesian Archipelago. By evaluating so-called network motifs, i.e. local-scale network structures, we quantify the fundamentally different functioning of these regions. Our results indicate that the moisture recycling streams in the Amazon Basin are more vulnerable to disturbances than in the three other main moisture recycling hubs.

How to cite: Wunderling, N., Staal, A., Wolf, F., Sakschewski, B., Hirota, M., Tuinenburg, O. A., Donges, J. F., Barbosa, H. M. J., and Winkelmann, R.: Recurrent droughts increase risk of cascading tipping events by outpacing adaptive capacities in the Amazon rainforest, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5722, https://doi.org/10.5194/egusphere-egu23-5722, 2023.

EGU23-7871 | Posters on site | CL3.2.6 | Highlight

Is the current methane growth event comparable to a glacial/interglacial Termination event? 

Euan Nisbet, Martin Manning, David Lowry, Rebecca Fisher, and James France

Atmospheric methane shows very sharp growth since 2006. Growing evidence for methane's main sink, atmospheric OH, being relatively stable implies a major increase in methane emissions is occurring. Methane's synchronous isotopic shift to more negative d13C(CH4) values means the increase is primarily driven by rapid growth in emissions from biogenic sources, such as natural wetlands and agriculture. Recent acceleration in the increase is also strong evidence that it is too large to be caused primarily by anthropogenic sources. Instead, much of the growth may come from large-scale climate-change feedbacks affecting the productivity and balance between methanogenic and methanotrophic processes in tropical and boreal wetlands. Emissions from tropical wetlands in particular may be larger and more influenced by climate shifts than hitherto realised. If so, even despite the Global Methane Pledge, achieving the goals of the UN Paris Agreement may be much harder than previously anticipated.

Modelling indicates that, for scale and speed, the biogenic feedback component of methane's growth and isotopic shift in the 16 years from 2006-2022 is comparable to (or greater than) phases of abrupt growth and isotopic shift during glacial/interglacial terminations, from Termination V (about 430 ka BP) to Termination I that initiated the Holocene. These were rapid global-scale climate shifts when the Earth system reorganised from cold glacial to warmer interglacial conditions.  Methane's recent 2006-2022 growth in biogenic sources may be within Holocene variability, but it is also a possibility that methane may be providing the first indication that a very large-scale end-of-Holocene reorganisation of the climate system is already under way: Termination Zero.

How to cite: Nisbet, E., Manning, M., Lowry, D., Fisher, R., and France, J.: Is the current methane growth event comparable to a glacial/interglacial Termination event?, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7871, https://doi.org/10.5194/egusphere-egu23-7871, 2023.

EGU23-9387 | ECS | Posters on site | CL3.2.6

Robustness of critical slowing down indicators to power-law extremes in an Amazon rainforest model 

Vitus Benson, Jonathan F. Donges, Jürgen Vollmer, and Nico Wunderling

Critical slowing down has recently been detected as an indicator of reduced resilience in remotely sensed data of the Amazon rainforest [1]. Tropical rainforests are frequently hit by disturbances such as fire, windthrow, deforestation or drought, which are known to follow a heavy-tailed amplitude distribution. Early warning signals based on critical slowing down are theoretically grounded for systems under the influence of weak, Gaussian noise. Hence, it is not imminent that they are applicable also for systems like the Amazon rainforest, which are influenced by heavy-tailed noise. Here, we extended a conceptual model of the Amazon rainforest [2] to study the robustness of critical slowing down indicators to power-law extremes. These indicators are expected to increase before a critical transition. 

We find the way by which such an increase is detected is decisive for the recall of the early warning indicator (i.e. the proportion of critical transitions detected by the indicator). If a linear slope is taken, the recall of the early warning signal is reduced under power-law extremes. Instead, the Kendall-Tau rank correlation coefficient should be used because the recall remains high in this case. Other approaches to increase robustness, like a high-pass filter or the interquartile range, are less effective. In [1], reduced resilience of the Amazon rainforest was determined through an increase in the lag-1 autocorrelation measured by the Kendall-tau rank correlation. Hence, if there was a resilience loss, they can correctly detect it even in the presence of relatively strong power-law disturbances. However, we also quantify the false positive rate, that is, how often a resilience loss is measured if the model represents a stable rainforest. At a significance level of 5% (1%, 10%) for the early warning signal detection, the false positive rate is approximately 10% (5%, 15%). For strong heavy-tailed noise, this false positive rate can deteriorate to as high as 25% (15%, 35%). This indicates, that increasing critical slowing down may not always be caused by an approaching critical transition, a false positive detection is possible.

 

[1] Boulton, C.,  Lenton, T.  and Boers, N.: “Pronounced Loss of Amazon Rainforest Resilience since the Early 2000s”. Nature Climate Change 12-3 (2022).

[2] Van Nes, E., Hirota, M., Holmgren, M. and Scheffer, M.: “Tipping Points in Tropical Tree Cover”. Global Change Biology 20-3 (2014).

How to cite: Benson, V., Donges, J. F., Vollmer, J., and Wunderling, N.: Robustness of critical slowing down indicators to power-law extremes in an Amazon rainforest model, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9387, https://doi.org/10.5194/egusphere-egu23-9387, 2023.

EGU23-9954 | ECS | Posters on site | CL3.2.6

Climate tipping risks under policy-relevant overshoot temperature pathways 

Tessa Möller, Ernest Annika Högner, Samuel Bien, Carl-Friedrich Schleussner, Johan Rockström, Jonathan F. Donges, and Nico Wunderling

The risk of triggering multiple climate tipping points if global warming levels were to exceed 1.5°C has been heavily discussed in recent literature. Current climate policies are projected to result in 2.7°C warming above pre-industrial levels by the end of this century and will thereby at least temporarily overshoot the Paris Agreement temperature goal.

Here, we assess the risk of triggering climate tipping points under overshoot pathways derived from emission pathways and their uncertainties from the PROVIDE ensemble using PyCascades, a stylised network model of four interacting tipping elements including the Greenland Ice Sheet, the West Antarctic Ice Sheet, the Atlantic Meridional Overturning Circulation, and the Amazon Rainforest.

We show that up until 2300, when overshoots are limited to 2°C, the upper range of the Paris Agreement goal, the median risk of triggering at least one element would be less than 5%, although some critical thresholds may have been crossed temporarily. However, the risk of triggering at least one tipping element increases significantly for scenarios that peak above the Paris Agreement temperature range. For instance, we find a median tipping risk in 2300 of 46% for an emission scenario following current policies. Even if temperatures would stabilize at 1.5°C after having peaked at temperatures projected under current policies, the long-term median tipping risks would approach three-quarters.

To limit tipping risks beyond centennial scales, we find that it is crucial to constrain any temperature overshoot to 2°C of global warming and to stabilize global temperatures at 1.0°C or below in the long-term.

How to cite: Möller, T., Högner, E. A., Bien, S., Schleussner, C.-F., Rockström, J., Donges, J. F., and Wunderling, N.: Climate tipping risks under policy-relevant overshoot temperature pathways, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9954, https://doi.org/10.5194/egusphere-egu23-9954, 2023.

EGU23-10044 | ECS | Orals | CL3.2.6 | Highlight

The Impact of Solar Radiation Modification on Earth System Tipping Points and Threshold Free Feedbacks 

Gideon Futerman and Claudia Wieners

The modification of the climate by Solar Radiation Modification (SRM) could be a potentially important human-Earth System interaction in the Anthropocene, having potentially beneficial and adverse impacts across climatic and human indices. SRM would likely interact with Earth system resilience in many ways, with our paper exploring SRM’s interaction with Earth System tipping point which has been extremely underexplored in the literature thus far.

SRM would likely be able to reduce global mean surface temperature quickly, although its broader climate imprint, especially on precipitation and local climatic conditions, is not the same as reversing greenhouse gas emissions. Its cooling effect suggests that SRM can help stop us from hitting those tipping elements that are most temperature-dependent, while the situation is more complex for tipping elements which strongly depend on other factors such as precipitation or regional climate changes. This more complex picture could have important implications for the role (or lack of) that SRM could and ought to play in improving Earth system resilience in the Anthropocene.

We review the available literature about the influence of SRM on the tipping elements and threshold free-feedbacks identified by McKay et al. (2022), as well as reviewing the impact of SRM on relevant climatic conditions that could contribute to tipping of each element, to give an assessment of the potential beneficial or adverse impact of SRM and identify key uncertainties and knowledge gaps. We will also briefly assess how these impacts may differ with different methods of deployment and with the termination of SRM.

How to cite: Futerman, G. and Wieners, C.: The Impact of Solar Radiation Modification on Earth System Tipping Points and Threshold Free Feedbacks, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10044, https://doi.org/10.5194/egusphere-egu23-10044, 2023.

EGU23-10864 | Posters on site | CL3.2.6

Towards the Anthropocene peatlands and forests – old-growth forest loss in Western Poland initiated peat growth and peatland state shifts 

Mariusz Lamentowicz, Sambor Czerwiński, Monika Karpińska-Kołaczek, Piotr Kołaczek, Mariusz Gałka, Piotr Guzowski, and Katarzyna Marcisz

During European states’ development, various past societies utilized natural resources, but their impact was not uniformly spatially and temporally distributed. Considerable changes resulted in landscape fragmentation, especially during the Middle Ages. Changes in state advances that affected the local economy significantly drove the trajectories of ecosystems’ development. The legacy of significant changes from pristine forests to farming is visible in natural archives as novel ecosystems. Here, we present two high‑resolution, densely dated multi‑proxy studies covering the last 1000 years from peatlands in CE Europe. In that case, the economic activity of medieval societies was related to the emerging Polish state and new rulers, the Piasts (in Greater Poland) and the Joannites (the Order of St. John of Jerusalem, Knights Hospitaller). Our research revealed rapid deforestation and subsequent critical land-use transition in the high and late Middle Ages and its consequences on the peatland ecosystem development. The shift from the old-growth forests correlates well with raising the local economy, deforestation and enhanced peat initiation. Along with the emerging landscape openness, the wetlands switched from wet fen with open water to terrestrial habitats. Both sites possess a different timing of the shift, but they also show that the catchment deforestation caused accelerated terrestrialization. Our data show how closely the ecological state of wetlands relates to forest microclimate. We identified a significant impact of economic development and the onset of intensive agriculture processes near the study sites. Our results revealed a surprisingly fast rate at which the feudal economy eliminated pristine nature from the studied area and led to intensive nature exploitation in the Anthropocene. In consequence, its activities led to the creation of novel peatlands types.

How to cite: Lamentowicz, M., Czerwiński, S., Karpińska-Kołaczek, M., Kołaczek, P., Gałka, M., Guzowski, P., and Marcisz, K.: Towards the Anthropocene peatlands and forests – old-growth forest loss in Western Poland initiated peat growth and peatland state shifts, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10864, https://doi.org/10.5194/egusphere-egu23-10864, 2023.

EGU23-13587 | ECS | Posters virtual | CL3.2.6

Model hierarchies and bifurcations in QE monsoon models 

Krishna Kumar S and Ashwin K Seshadri

The convective quasi-equilibrium (CQE) framework has been successfully employed in the past to build intermediate complexity models accounting for the interaction of convection and large-scale dynamics (Neelin and Zeng, 1999, JAS). As a consequence, these models find use in the study of monsoon circulations, which also experience abrupt onset among several other intriguing features. While some low-order simplifications of CQE based Quasi-equilibrium tropical circulation model (QTCM) yields insights into the mechanisms of monsoon dynamics, they are restricted in the range of processes accounted for. A hierarchy of models, on the other hand, would serve well to study monsoon dynamics and various influences. While the existence of bifurcations or 'tipping-points' in monsoon dynamics has been studied for certain simple models, a thorough investigation of this possibility across a hierarchy of models is absent. Such a hierarchy of models would provide an understanding of effects of different simplifying assumptions on dominant balances in the momentum and thermodynamic equations and resulting nonlinear dynamics, including the choice of precipitation parameterizations. This study explores a hierarchy of such models of varying complexity, based on the QTCM equations. The potential occurrence of bifurcation phenomena are considered, along with their sensitivity to various parameter changes, in the context of the role of different nonlinearities present in these models. The study builds on recent results interpreting the suppression of bifurcation phenomena in these models, as a result of shifts in equilibrium branches and consequently their physical relevance. The hierarchy of models approach, in this context, reconciles apparent contradictions between bifurcations being observed in the simplest models and the evidence from more complex models as well as observations, while identifying robust phenomena.

How to cite: Kumar S, K. and Seshadri, A. K.: Model hierarchies and bifurcations in QE monsoon models, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13587, https://doi.org/10.5194/egusphere-egu23-13587, 2023.

EGU23-13620 | Orals | CL3.2.6

The Western Amazon social-ecological system at risk of tipping: A transdisciplinary modelling approach 

Benjamin Stuch, Rüdiger Schaldach, Regine Schönenberg, Katharina Meurer, Merel Jansen, Claudia Pinzon Cuellar, Shabeh Ul Hasson, Christopher Jung, Ellen Kynast, Jürgen Böhner, and Hermann Jungkunst

The Amazon rainforest is a tipping element of the global climate system due to its high carbon storage potential and its flying rivers providing rain for South America. Studies suggest that land use and land cover change (LUCC) in the Amazon, i.e. deforestation, strongly disturb regional convectional rain pattern, which could lead to an increase of drought frequencies and intensities. Under increasing drought stress, the evergreen tropical rainforest may transform into a seasonal forest or even a savannah ecosystem. Such a transformation would likely activate the Amazon tipping element and may affect global climate change by triggering other critical tipping elements of the global climate system.  

Here we present our transdisciplinary research approach in the Western Amazon rainforest developed in context of the PRODIGY research project. We apply a social-ecological system approach to account for the dynamic interactions and feedbacks between people and nature, which could either stabilize or self-enforce regional tipping cascades. For example, regional land users may suffer declining yield and net primary production from decreasing precipitation. Land users may compensate the drop in production/income e.g. by cultivating more land or seeking for other income sources. As a response, deforestation could increase which may drive a self-enforcing feedback loop that further decrease precipitation.

In a participatory process, together with regional stakeholders we develop land use related explorative scenarios. Preliminary results from the scenario exercise show that future agricultural production increases in all scenarios (crops between 20% and 200% and livestock between 0% and 300%). In the first modelling step, these  changes drive the regionally adjusted spatial land system model LandSHIFT. Simulation results indicate that deforestation increases in all scenarios depending on the production technology and the reflexivity of institutions establishing appropriate management options.

In an integrated modelling step, the calculated LUCC maps serve as input to a regional climate model (WRF), which simulates respective changes in regional temperature and precipitation. Then, temperature and precipitation changes are applied to the biogeochemical model CANDY to simulate the impact (of regional deforestation) on crop yields, Net Primary Production (NPP) and changes in soil C and N cycling. In an iterative process, the yield and NPP responses are fed back to the land-use change model to simulate the required land use adaptations, accordingly. By closing the feedback loop between deforestation, climate, yield and NPP as well as respective land use adaptation, we are able to simulate a cascade of endogenous key process in the regions social ecological system. The integrated modelling results will support the stakeholders in identifying key measures/options/policies that could increase resilience of the regional social-ecological system to prevent crossing destructive regional tipping points.

How to cite: Stuch, B., Schaldach, R., Schönenberg, R., Meurer, K., Jansen, M., Pinzon Cuellar, C., Ul Hasson, S., Jung, C., Kynast, E., Böhner, J., and Jungkunst, H.: The Western Amazon social-ecological system at risk of tipping: A transdisciplinary modelling approach, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13620, https://doi.org/10.5194/egusphere-egu23-13620, 2023.

Microbial communities in freshwater lake sediments play a crucial role in regulating geochemical cycles and controlling greenhouse gas emissions. Many of them exhibit a highly ordered structure along depth profile. Besides redox effect, sediment stratification could also reflect historical transition. Dam construction dramatically increased in the mid-20th century and is considered one of the most far-reaching anthropogenic modifications of aquatic ecosystems. Here we attempted to identify the effect of historical dam construction on sediment microbial zonation in Lake Chaohu, one of the major freshwater lakes in China. The damming event in AD 1962 was coincidentally labeled by the 137Cs peak. Physiochemical and sequencing analyses (16S amplicon and shotgun metagenomics) jointly showed a sharp transition occurred at the damming-labeled horizon which overlapped with the nitrate-methane transition zone (NMTZ) and controlled the depth of methane sequestration. At the transition zone, we observed significant taxonomic differentiation. Random forest algorithm identified Bathyarchaeota, Spirochaetes, and Patescibacteria as the damming-sensitive phyla, and Dehalococcoidia, Bathyarchaeia, Marine Benthic Group A, Spirochaetia, and Holophagae as the damming-sensitive classes. Phylogenetic null model analysis also revealed a pronounced shift in microbial community assembly process, from a selection-oriented deterministic community assembly down to a more stochastic, dispersal-limited one. These findings delineate a picture in which dam-induced changes to the lake trophic level and sedimentation rate generate great changes in sediment microbial community structure, energy metabolism, and assembly process.

How to cite: Zhou, X. and Ruan, A.: Dam construction as an important anthropogenic modification triggers abrupt shifts in microbial community assembly in freshwater lake sediments, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14360, https://doi.org/10.5194/egusphere-egu23-14360, 2023.

EGU23-14772 | Posters on site | CL3.2.6

Sustainable Pathways under Climate Variability 

Kira Rehfeld and the SPACY research group members

External forcings and feedback processes of the Earth system lead to timescale and state-dependent climate variability, causing substantial surface climate fluctuations in the past. Particularly relevant for future livelihoods, changing variability patterns could also modify the occurrence of extreme events. However, spatiotemporal mechanisms of climate variability are poorly understood. Likewise, the societal implications are weakly constrained, particularly variability’s potential to drive sustainable transformation. The SPACY project investigates climate variability from past cold and warm periods to future scenarios. One research focus is how forcing mediates climate fluctuations. Bridging the gap between Earth system models and palaeoclimate proxies, we study vegetation and water isotope changes. A second focus is exploring sustainable pathways under climate variability, addressing potential interactions between artificial carbon dioxide removal and surface climate, among others.

 

In particular, we validate the ability of climate models to represent potential climate variability changes. Here, we focus on isotope-enabled simulations with dynamic vegetation. We find that models exhibit less local temperature and water isotope variability than paleoclimate proxies on decadal and longer timescales. Simulations with natural forcing agree much better with proxy records than unforced ones. The mean local temperature variability decreases with warming. Furthermore, we analyze potentials and limitations of terrestrial hydroclimate proxies. This includes water isotopes in speleothems and ice cores and vegetation indicators derived from pollen assemblages.

Transferring our understanding to the future, we contribute to mitigation and sustainable transitions. Weather and climate extremes determine losses and damages, but their impact on socioeconomic development is poorly examined. We scrutinize damage parametrization of economic models regarding the ability to consider variability. While large-scale sequestration of atmospheric carbon dioxide is paramount to mitigation targets, its representation in climate models is insufficient. Accounting for feedbacks of carbon dioxide removal (CDR) requires model experiments with modified land surfaces. We develop CDR representations of “artificial photosynthesis” in Earth system models. Pollen records benchmark the simulated climate–carbon dioxide–vegetation interactions. This supports modeling endogenous societal land use decisions in the future.

Our work continues to improve the understanding of long-term climate predictability. The combined knowledge from past climate studies and comprehensive modeling for future scenarios underlines the relevance of changing boundary conditions for a future within planetary boundaries.

 

 

How to cite: Rehfeld, K. and the SPACY research group members: Sustainable Pathways under Climate Variability, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14772, https://doi.org/10.5194/egusphere-egu23-14772, 2023.

EGU23-16944 | ECS | Orals | CL3.2.6

Socio-Political Feedback on the Path to Net Zero 

Saverio Perri, Simon Levin, Lars Hedin, Nico Wunderling, and Amilcare Porporato

Anthropogenic emissions of CO2 must soon approach net zero to stabilize the global mean temperature. Although several international agreements have advocated for coordinated climate actions, their implementation has remained below expectations. One of the main challenges of international cooperation is the different degrees of socio-political acceptance of decarbonization.

In this contribution, we interrogate a minimalistic model of the coupled human-natural system representing the impact of such socio-political acceptance on investments in clean energy and the path to net-zero emissions. Despite its simplicity, the model can reproduce complex interactions between human and natural systems, and it can disentangle the effects of climate policies from those of socio-political acceptance on the path to net zero. Although perfect coordination remains unlikely, as clean energy investments are limited by myopic economic strategies and a policy system that promotes free-riding, more realistic decentralized cooperation with partial efforts from each actor could still lead to significant emissions cuts.

Since the socio-political feedback on the path to net zero could influence the trajectories of the Earth System for decades to centuries and beyond, climate models need to incorporate better the dynamical bi-directional interactions between socio-political groups and the environment. Our model represents a first step for incorporating this feedback in describing complex coupled human and natural systems.

How to cite: Perri, S., Levin, S., Hedin, L., Wunderling, N., and Porporato, A.: Socio-Political Feedback on the Path to Net Zero, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16944, https://doi.org/10.5194/egusphere-egu23-16944, 2023.

EGU23-17342 | ECS | Orals | CL3.2.6

Systematic assessment of climate tipping points 

Sina Loriani, Boris Sakschewski, Jonathan Donges, and Ricarda Winkelmann

Tipping elements constitute one high-risk aspect of anthropogenic climate change - after their critical thresholds are passed, self-amplifying feedbacks can drive parts of the Earth system into a different state, potentially abruptly and/or irreversibly. A variety of models of different complexity shows these dynamics in many systems, ranging from vegetation over ocean circulations to ice sheets. This growing body of evidence supports our understanding of  potential climate tipping points, their interactions and impacts.

However, a systematic assessment of Earth system tipping points and their uncertainties in a dedicated model intercomparison project is of yet missing. Here we illustrate the steps towards automatically detecting abrupt shifts and tipping points in model simulations, as well as a standardised evaluation scheme for the Tipping Point Model Intercomparison Project (TIPMIP). To this end, the model outputs of taylored numerical experiments are screened for potential tipping dynamics and spatially clustered in a bottom-up approach. The methodology is guided by the anticipated setup of the intercomparison project, and in turn contributes to the design of the TIPMIP protocol.

How to cite: Loriani, S., Sakschewski, B., Donges, J., and Winkelmann, R.: Systematic assessment of climate tipping points, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17342, https://doi.org/10.5194/egusphere-egu23-17342, 2023.

EGU23-17397 | ECS | Posters virtual | CL3.2.6

Is Arctic Permafrost a Climate Tipping Element? – Potentials for Rapid Permafrost Loss Across Spatial Scales 

Jan Nitzbon, Thomas Schneider von Deimling, Sarah Chadburn, Guido Grosse, Sebastian Laboor, Hanna Lee, Norman Julius Steinert, Simone Maria Stuenzi, Sebastian Westermann, and Moritz Langer

Arctic permafrost is yet the largest non-seasonal component of Earth's cryosphere and has been proposed as a climate tipping element. Already today, permafrost thaw and ground ice loss have detrimental consequences for Arctic communities and are affecting the global climate via carbon-cycle–feedbacks. However, it is an open question whether climatic changes drive permafrost loss in a way that gives rise to a tipping point, crossing of which would imply abrupt acceleration of thaw and disproportional unfolding of its impacts.

Here, we address this question by geospatial analyses and a comprehensive literature review of the mechanisms and feedbacks driving permafrost thaw across spatial scales. We find that neither observation-constrained nor model-based projections of permafrost loss provide evidence for the existence of a global-scale tipping point, and instead suggest a quasi-linear response to global warming. We identify a range of processes that drive rapid permafrost thaw and irreversible ground ice loss on a local scale, but these do not accumulate to a non-linear response beyond regional scales.

We emphasize that it is precisely because of this overall linear response, that there is no „safe space“ for Arctic permafrost where its loss could be acceptable. Every additional amount of global warming will proportionally subject additional land areas underlain by permafrost to thaw, implying further local impacts and carbon emissions.

How to cite: Nitzbon, J., Schneider von Deimling, T., Chadburn, S., Grosse, G., Laboor, S., Lee, H., Steinert, N. J., Stuenzi, S. M., Westermann, S., and Langer, M.: Is Arctic Permafrost a Climate Tipping Element? – Potentials for Rapid Permafrost Loss Across Spatial Scales, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17397, https://doi.org/10.5194/egusphere-egu23-17397, 2023.

EGU23-17457 | ECS | Orals | CL3.2.6 | Highlight

Indicators of changing resilience and potential tipping points in the automotive industry 

Joshua E Buxton, Chris A Boulton, Jean-Francois Mercure, Aileen Lam, and Timothy M Lenton

Through innovation and wider socio-economic processes, large sections of the economy have been known to rapidly (and often irreversibly) transition to alternative states. One such sector currently undergoing a transition is the automotive industry, which is moving from a state dominated by internal combustion engines to one characterised by low-emission vehicles. While much research has focused on early warning signals of climate and ecological tipping points, there is much to be done on assessing the applicability of these methods to social systems. Here we focus on the potential for tipping points to occur in the sale of electrical vehicles in various markets, including Norway and the UK. Early indicators that this new state is being approached are considered through the use of novel data sources such as car sales, infrastructure announcements and online advert engagement. We then map out the socio-technical feedback loops which may drive these tipping points. Consideration is also given to the resilience of the wider automotive industry to previous economic shocks. 

How to cite: Buxton, J. E., Boulton, C. A., Mercure, J.-F., Lam, A., and Lenton, T. M.: Indicators of changing resilience and potential tipping points in the automotive industry, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17457, https://doi.org/10.5194/egusphere-egu23-17457, 2023.

EGU23-1477 | ECS | Orals | SSP1.4

Microplastic Interaction with Soil Water - Visualization and Quantification with Neutron and X-ray Imaging 

Andreas Cramer, Pascal Benard, Kaestner Anders, Mohsen Zarebanadkouki, and Andrea Carminati

Soil is considered the largest sink of microplastics (MP) in terrestrial ecosystems. Among the expected effects of MP as hydrophobic surface addition is the likelihood that MP enhances soil water repellency. So, crucial for MP fate in soils is the interaction between MP and water. If MP is translocated by water flow and, vice versa, MP impacts water flow, to what extent? Water flow on the pore scale will be impacted with feedbacks on transport and retention of MP. However, we don’t know the extent of and conditions under which MP are transported through porous media and, if deposited, how they interplay with soil water dynamics. We hypothesize that: (i) isolated MP are displaced and translocated by air-water interfaces and (ii) local accumulation of MP is facilitated by bypassing water flow. To approach this question, neutron and x-ray imaging of MP and water in soils was utilized.

Dual neutron and x-ray imaging at the beamlines ICON (Paul-Scherrer-Institute) during repeated wetting-drying cycles was applied to trace MP-water interactions in aluminum cylinders filled with sand (0.7-1.2 mm) and MP (PET, 20-75 µm) in gravimetric contents of 0.35, 1.05 and 2.10%. The contents refer to static contact angle estimations of the mixtures resembling < 90°, 90° and > 90°. First, simultaneous neutron and x-ray tomography captured the initial dry MP configuration in samples. Subsequently, neutron radiographies of deuterated water flow through the sample of 1 ml min-1 were recorded for 200s. After drying, repeated tomography gave insights into MP translocation.

Neutron and x-ray imaging results showed that regions of major MP content are water repellent. Water flow bypasses and MP is mainly retained. Resultant air entrapments lead to reduced water contents. In regions of minor MP content water can infiltrate. Here, the air-water interface collects isolated MP and shifts their distribution towards an enhanced accumulation.

Extrapolation of these results to natural soil systems suggests that vertical transport of MP can be limited especially at hotspots of high MP contents. Water bypasses here. This might limit the water dependent degradation processes of MP due to reductions in hydrolysis, coating and colonization by microorganisms even elongating the process of natural attenuation.

How to cite: Cramer, A., Benard, P., Anders, K., Zarebanadkouki, M., and Carminati, A.: Microplastic Interaction with Soil Water - Visualization and Quantification with Neutron and X-ray Imaging, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1477, https://doi.org/10.5194/egusphere-egu23-1477, 2023.

EGU23-2559 | ECS | Posters on site | SSP1.4

Leaching of carbon, metals, and additives from microplastics to water 

Katerina Novotna, Lenka Cermakova, and Martin Pivokonsky

The occurrence of microplastics (MPs) has been evidenced worldwide in various aquatic environments, and while quite many studies have been devoted to the quantification and characterisation of these MPs, the knowledge of potential leaching from MPs to water is yet limited. In the current study, a range of different MPs prepared from consumer plastic products were soaked in water for 12 weeks, and variable composition of the water leachates was continuously analysed. Majority of investigated MPs released substantial amounts of dissolved organic carbon, with the maximum of approximately 65 mg per g of MPs after the 12 weeks, and some MPs also released dissolved inorganic carbon. Additionally, up to 10 other elements were detected in individual leachates – including metals (Al, Ba, Ca, Fe, K, Mg, Mn, Na, Zn) and one metalloid (Si). Out of those, Ca, K, and Na occurred most frequently, while Ca reached the highest values (up to approximately 2.5 mg per g MPs). In general, the overall highest leaching was observed in the case of MPs comprising polyurethane, polyvinyl chloride, and acrylonitrile-butadiene copolymer as the main polymers. Another general observation is that the leaching was usually most rapid during the first few weeks of MP contact with water. Further, in order to provide a better insight into composition and properties of the leachates, non-target analysis was conducted, and dozens of chemical individuals were tentatively identified in the leachates. Considering that the amounts of some elements released from MPs were quite high, and that some of the tentatively identified compounds are considered harmful to human health and/or to the environment, the leaching from MPs to ambient water might be important from different perspectives, including toxicology as well as fluxes of carbon and metals.

How to cite: Novotna, K., Cermakova, L., and Pivokonsky, M.: Leaching of carbon, metals, and additives from microplastics to water, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2559, https://doi.org/10.5194/egusphere-egu23-2559, 2023.

EGU23-2560 | ECS | Posters on site | SSP1.4

Investigating microplastics at two drinking water treatment plants within a river catchment 

Lenka Cermakova, Katerina Novotna, and Martin Pivokonsky

Microplastics (MPs) are emerging globally distributed pollutants of aquatic environments. Nowadays, MPs are being detected in seas, oceans and freshwater bodies worldwide, even in very remote areas. Studies have reported also the occurrence of MPs in potable water. Despite the potential adverse effects on human health are still largely unknown, the presence of MPs in drinking water deserves more attention. Besides the need for elimination of MPs in natural environments, it is necessary to focus also on their fate and removability at drinking water treatment plants (DWTPs) that pose a barrier for MPs to enter water for human consumption. In our study, we decided to provide unique insight into the occurrence of MPs at two different DWTPs situated on the same river but differing in treatment technology. Quantification and characterization of MPs ≥ 1 μm was conducted not only in raw and treated water but also after each technological treatment step. The results showed that the content of MPs varied greatly between the DWTPs. There were 23 ± 2 and 14 ± 1 MPs L−1 in raw and treated water, respectively, at the upstream DWTP. By contrast, 1296 ± 35 and 151 ± 4 MPs L−1 were found in raw and treated water, respectively, at the downstream DWTP. The majority (>70%) of MPs were smaller than 10 μm, and irregular fragment shape prevailed over fibres. Cellulose acetate, polyethylene terephthalate, polyvinyl chloride, polyethylene, and polypropylene were the most frequently occurring materials. Total removal of MPs of 88% was achieved at the DWTP with a higher initial MP number and more complicated treatment technology consisting of coagulation-flocculation-sedimentation, deep-bed filtration through clay-based material, and granular activated carbon adsorption. These steps contributed to MP elimination by 62%, 20%, and 6%, respectively. These results contribute to filling the knowledge gap regarding the removability of different types of MPs by distinct drinking water treatment technologies operating under ordinary conditions.

How to cite: Cermakova, L., Novotna, K., and Pivokonsky, M.: Investigating microplastics at two drinking water treatment plants within a river catchment, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2560, https://doi.org/10.5194/egusphere-egu23-2560, 2023.

EGU23-2670 | ECS | Posters on site | SSP1.4

Soil susceptibility to wind erosion drives the abundance of microplastics in remote Scottish soils 

Tereza Pavlíková, David Pavlík, Jan Divíšek, and Daniel Nývlt

Microplastics have been found in various places, including not only densely populated areas of China or Germany but also remote high-altitude places like the Himalayas or the Pyrenees. However, the remoteness of a place is not determined only by its altitude. The Outer Hebrides (Scotland), with a low population and minimum industry, are remote in terms of direct pollution. This study aims to analyse the occurrence and spatial distribution of microplastics in soils of the Outer Hebrides to discover the factors driving the abundance of microplastics and to find how much more or less are remote Scottish soils polluted with microplastics than inland soils of populated areas.

In the Isle of South Uist, 123 topsoil samples were collected along the western coastline and in four transects through the isle in the west-east direction. In total, 63 samples were analysed using an optical microscope to quantify the plastic microfibres visually using a semi-automatic algorithm. The amounts of microfibres were statistically processed, and their distribution was modelled for the entire archipelago.

More microplastics are present in inland soils with loamy soil texture, denser vegetation and denser roots (median = 36,900 microfibres/L) than in coastal soils with sandy soil texture, sparse vegetation and low root density (median = 3,580 microfibres/L). Their abundance is mainly influenced by soil texture, vegetation density, and root density.

With the south-western prevailing wind direction, we assume that most microfibres enter the island from the Atlantic Ocean, and the wind transports the microfibres inland to the east. Wind deflates the microfibres from coastal soils, and microfibres are deposited in inland soils. The inland soils are less susceptible to wind erosion, and the microfibres accumulate there.

Thus, the remoteness of the Outer Hebrides does not guarantee low microplastic pollution. Contrarily, the Hebridean soils are extensively more polluted than most so far studied sites. The level of pollution is comparable to only a few studies where the abundance of microplastics in the soils is similar, e.g. Beijing (China), Lower Rhine basin (Germany) or Coimbra (Portugal). However, these sites are much more populated and interconnected, which suggests a great contribution of microplastic pollution from Atlantic Ocean and a great magnitude of wind transport processes in the Outer Hebrides.

How to cite: Pavlíková, T., Pavlík, D., Divíšek, J., and Nývlt, D.: Soil susceptibility to wind erosion drives the abundance of microplastics in remote Scottish soils, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2670, https://doi.org/10.5194/egusphere-egu23-2670, 2023.

EGU23-2997 | Posters on site | SSP1.4

The circularity of marine microplastics under the influence of climate change 

Chihhao Fan and You-Yi Lee

Since plastics were first made in the early 20 century, global plastic production has increased dramatically and annual plastic use reached 460 million metric tons (Mt) in 2019. Although the advent of plastics creates miraculous economic achievements, it brings about severe pollution at the same time. As the life cycle of plastic use worldwide is still in linear form, mismanaged plastic waste might break into microplastics and accumulate in the environment. Rivers are the main route by which plastics enter the ocean. The process may take years or decades for microplastics to reach the ocean. The ocean surface currents were responsible for the transport of plastic waste and the ocean is its ultimate destination. This study correlated the fate of marine microplastics with economic growth under the influence of climate change. Taking 1960 as a benchmark, the trend of world GDP growth coincided with the growth of annual plastic production, indicating that economic growth heavily relies on plastic-related industries. Plastics emit a high amount of greenhouse gas (GHG) through their life span, enhancing the negative impact of climate change, causing the faster weathering process to form microplastics, and further enabling the leakage into the aquatic environment. According to the OECD statistics, 1.7 Mt of plastics entered the ocean system in 2019, reaching the total accumulation of 30 Mt of plastic waste since 1970. Global warming over past decades enhances the Earth's ocean currents which induced the acceleration of ocean plastic distribution. The accelerated ocean transportation may increase plastic accumulation at the garbage patches within five gyres and the Arctic Ocean which are ultimate sinks for plastic waste in the ocean. The abundance of microplastics in the ocean interferes with the carbon fixation capacity of the ocean, forming a nexus implication between climate change, ocean currents, and marine plastic redistribution. The accumulation of marine microplastic is suggested to be a factor in aggravating the impact of climate change. To deal with the dilemma, economic growth should be decoupled with the massive use of plastic utilization to reduce plastic production and GHG emission. Moreover, higher plastic waste recycling is urgently needed to prevent extra microplastics from entering the ocean.

How to cite: Fan, C. and Lee, Y.-Y.: The circularity of marine microplastics under the influence of climate change, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2997, https://doi.org/10.5194/egusphere-egu23-2997, 2023.

EGU23-4405 | Orals | SSP1.4 | Highlight

The Plastic Underground: Are Microplastics in the Subsurface a Ticking Time Bomb for Soil and Groundwater Ecosystems? 

Stefan Krause, Uwe Schneidewind, Mohammad Wazne, Anna Kukkola, Iseult Lynch, Lee Haverson, Liam Kelleher, Grace Davies, Andre-Marie Dendievel, Brice Mourier, Florian Mermillod-Blondin, Zoraida Quiñones-Rivera, Laurent Simon, Julia Reiss, Dan Perkins, Anne Robertson, and Jesus Gomez-Velez

Increasing volumes of mismanaged plastic waste have resulted in millions of tons of plastics entering the environment. While recent research has made substantial progress in determining the fate and transport of microplastics (MP) in river systems and their subsequent discharge to the worlds oceans, much less is known about the subsurface fate of MP as they enter soils, (riverine) sediments and global groundwater resources. Initial studies have identified MP in selected groundwater samples and there is great interest to understand entry pathyways of MPs into soils, in particular through agricultural pathways. The mechanisms of MP release from agricultural sources such as seed and agrochemical encapsulations or sewage sludges as well as the total quantity, spatial distribution, residence time scales as well as the impact of MP on soils and subsequently groundwater ecosystems are completely unknown. There is hence a critical need to study the role of soils and groundwater systems as a long-term sink for plastic pollution, including the development of legacy risks.

Here we identify the significance of various entry pathways for MP into subsurface ecosystems, integrating experimental and model based quantifications of MP transport through streambed sediments with quantifications of MP inputs into agricultural soils through irrigation with river water. We present first results of MP impacts on the functioning of subsurface ecosystem services, by the particular example of MP exposure impacts on the behaviour of bioturbating invertebrates and the subsequent consequences for sediment biogeochemical cycling in order to draw attention to the potential risks for vital soil and groundwater ecosystem services.

We complement this site specific mechanistic process understanding with global estimates of mismanaged plastic waste accumulation in river basins to quantify MP catchment wide loads available for leakage into soils and present first results of our recently started participatory approach that aims to develop a baseline of MP pollution in aquifers across the world. Such baseline data is imperative to increase our understanding of MP fate and transport processes, MP uptake by groundwater organisms and the interaction of MP with nutrients and potential co-contaminants. Our specifically tailored protocol allows for standardized MP sampling in boreholes, springs or wells across a wide range of geological settings and land cover classes. We invite and encourage the community to contribute to this global effort in order to enable estimates of the magnitude and expected time scales of soil and groundwater MP contamination.

How to cite: Krause, S., Schneidewind, U., Wazne, M., Kukkola, A., Lynch, I., Haverson, L., Kelleher, L., Davies, G., Dendievel, A.-M., Mourier, B., Mermillod-Blondin, F., Quiñones-Rivera, Z., Simon, L., Reiss, J., Perkins, D., Robertson, A., and Gomez-Velez, J.: The Plastic Underground: Are Microplastics in the Subsurface a Ticking Time Bomb for Soil and Groundwater Ecosystems?, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4405, https://doi.org/10.5194/egusphere-egu23-4405, 2023.

EGU23-4586 | ECS | Orals | SSP1.4

Spatial distribution and historical trend of microplastic pollution in sediments from enclosed bays of South Korea 

Soeun Eo, Sang Hee Hong, Young Kyoung Song, Youna Cho, Gi Myung Han, and Won Joon Shim

Seafloor sediment is an important sink for microplastics, and vertical profile of microplastic accumulation in a sediment core can provide historical pollution trend. However, microplastic pollution in coastal sediment has not been addressed well, and a few studies have investigated the trends of microplastic pollution in age-dated core sediments. In this study, the microplastics in surface sediments in urban, aquafarm and reference areas of South Korea were analyzed to evaluate the pollution characteristics of microplastic according to different sea area use patterns. In addition, the historical trend of microplastic pollution was investigated in core sediments in the urban and aquafarm areas. The abundance of microplastics in surface sediment were in order of urban area (6,887 ± 6,100 particles/kg d.w.), aquafarm area (5,121 ± 2,428 particles/kg d.w.), and reference area (2,474 ± 522 particles/kg d.w.). Polymer types were diverse in the urban area, and expanded polystyrene used for buoys was dominant in the aquafarm area. Fragment type microplastic was dominant in all three areas, and the proportion of fiber was higher in urban and aquafarm areas than in reference area. The polymer composition of fiber was different in urban (polyester 51% and polypropylene (PP) 29%) and aquafarm areas (PP 84% and polyamide 13%). These results support that the characteristics of microplastic pollution well reflect the sea area use patterns. Historical trend of microplastic pollution has increased since the 1980s and the increasing rate steeply increased around the early and mid-2000s in both the core samples. Their increasing trend reflected the influence of population or surrounding input sources (i.e. effluent discharge amount of a wastewater treatment plant). The clear increasing trend of historical microplastic pollution up to now indicates that more efforts is highly required to reduce the microplastic pollution. 

How to cite: Eo, S., Hong, S. H., Song, Y. K., Cho, Y., Han, G. M., and Shim, W. J.: Spatial distribution and historical trend of microplastic pollution in sediments from enclosed bays of South Korea, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4586, https://doi.org/10.5194/egusphere-egu23-4586, 2023.

EGU23-5676 | ECS | Orals | SSP1.4

Microplastic distribution characteristics and storage in a multi-species saltmarsh 

Yan Zhang, Yanting Wang, Xiaogang Chen, Peiyuan Zhu, Siyuan Jing, and Ling Li

Plastic has greatly changed modern society, and it has become an indispensable material in our daily lives. Microplastics are now regarded as the serious environmental threats due to the management limitations. Saltmarshes are one of the most productive ecosystems on earth and a high-efficiency blue carbon sink. As an emerging contaminant, the load, transport and fate of microplastics are largely neglected in saltmarshes. Here, we firstly measured the mass concentration of microplastics in the sediment cores of a multi-species saltmarsh by pressurized liquid extraction and modified double-shot pyrolysis gas chromatography-mass spectrometry. The major microplastics in saltmarsh sediments were polyethylene (PE), polyvinyl chloride (PVC), and polypropylene (PP). The microplastic mass concentration in the sediment of Scirpus mariqueter was greater than Phragmites australis and mudflat. As artificial carbon, carbon content of microplastics accounts for 1.15% of total organic carbon. Overall, the results suggest that saltmarsh vegetation can efficiently drive the microplastic settling and retention. Therefore, the microplastic distribution characteristics in saltmarsh can be effected by the vegetation types and their distribution pattern.

How to cite: Zhang, Y., Wang, Y., Chen, X., Zhu, P., Jing, S., and Li, L.: Microplastic distribution characteristics and storage in a multi-species saltmarsh, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5676, https://doi.org/10.5194/egusphere-egu23-5676, 2023.

EGU23-6323 | ECS | Posters on site | SSP1.4

The impacts of climate change on eroding coastal historic landfills 

Shudan Xue, Kate Spencer, and Stuart Grieve

Impacts of climate change – sea level rise, more frequent storms and coastal flooding will exacerbate coastal erosion, resulting in the erosion of coastal historic landfills. These historic landfills are particularly vulnerable to such erosion as they typically have no lining or leachate management, limited information of the proportion and/or types of waste mixtures they contain and inaccurate records of their location and waste volumes. There are over 1200 coastal historic landfills in England alone, and over 10,000 such sites are at risk of release both solid waste and soluble contaminants across Europe. The contaminated matrix and solid wastes make landfills a major sink and source of microplastics and heavy metal, posing a threat to the coastal and marine environment.

We investigated heavy metal and microplastic pollution on the beach and foreshore in three coastal historic eroding landfills, East Tilbury (n = 32 samples), Lynemouth (n = 33 samples), Northam Burrows Tilbury (n = 33 samples), UK. Samples were collected every 50 meters along the shoreline, with 100g of surface soil from the landfill edge, and 1kg of beach and intertidal sediment collected from each transect. The metal concertation was measured with handheld X-ray Fluorescence (XRF). Microplastics were density separated with a zinc chloride solution (1.5 g cm−3), after the samples were dried and digested with hydrogen peroxide. The extracted microplastics were recorded under stereomicroscope at 50× magnification with a digital camera, and characterized with Fourier-transformed infrared (ATR-FTIR) spectroscopy.

This study is one of the first few to investigate the impacts of eroding historic landfill. Our preliminary findings suggest that eroding landfill are releasing significant amounts of microplastics and heavy metal pollution. These findings will be crucial to assess the impacts of eroding landfills, identify solutions and raise public attention to this environmental problem.

How to cite: Xue, S., Spencer, K., and Grieve, S.: The impacts of climate change on eroding coastal historic landfills, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6323, https://doi.org/10.5194/egusphere-egu23-6323, 2023.

EGU23-9164 | ECS | Orals | SSP1.4 | Highlight

River plastic during floods: Amplified mobilization, limited river-scale dispersion 

Tim van Emmerik, Roy Frings, Louise Schreyers, Rahel Hauk, Sjoukje de Lange, and Yvette Mellink

Plastic mobilization, transport, and retention dynamics are influenced by hydrological processes and river catchment features (e.g. land-use, vegetation, and river morphology). Increased river discharge has been associated with higher plastic transport rates, although the exact relation between the two can vary over time and space. The precise role of an extreme discharge event on plastic transport is however still unknown. Here, we show that fluvial floods drive floating macroplastic transport and accumulation in river systems. We collected observational evidence during the (return period of 200 years) along the Dutch part of the Meuse. Upstream plastic transport multiplied by a factor of over 100 compared to non-flood conditions (3.3x105 vs 2.3x102), making the Meuse . Over one-third of the annual plastic transport was estimated to occur within the six-day period of extreme discharge (>3,200 m3/s). Towards the river mouth, plastic transport during the flood decreased by 90%, suggesting that the Plastic transport and accumulation on the riverbanks decreased significantly along the river, corroborating the river's function as a plastic reservoir, rather than conduit for plastic towards the ocean. We demonstrate the crucial role of floods as drivers of plastic transport and accumulation in river systems. Floods amplify the mobilization of plastics, but the effects are local and the river-scale dispersion is limited. We anticipate that our findings serve as a starting point for improving global estimates of river plastic transport, retention, and export into the sea. Moreover, our results provide essential insights for future large-scale and long-term quantitative assessments of river plastic pollution. Reliable observations and a fundamental understanding of plastic transport are key to designing effective prevention and reduction strategies.

 

Link to preprint

Tim van Emmerik, Roy Frings, Louise Schreyers et al. River plastic during floods: Amplified mobilization, limited river-scale dispersion, 08 August 2022, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-1909246/v1]

How to cite: van Emmerik, T., Frings, R., Schreyers, L., Hauk, R., de Lange, S., and Mellink, Y.: River plastic during floods: Amplified mobilization, limited river-scale dispersion, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9164, https://doi.org/10.5194/egusphere-egu23-9164, 2023.

EGU23-10534 | ECS | Orals | SSP1.4

Greenland in the Anthropocene: an archive of microplastic pollution 

Karla B Parga Martinez, Thorbjørn J Andersen, Vitor da Silva, Jakob Strand, and Nicole R Posth

Glacimarine sediment results from glaciers weathering the rock exporting silt and clay into the ocean. Such fine sediments are also exported from the Greenlandic Ice Sheet where new sources of plastic pollution like seasonal ice thawing may be releasing microplastics (MP) back to the environment. MP could be then transported to the seafloor via sediment burial and incorporated into the layers of the geological record. However, the purification and extraction of MP from such a fine-grain matrix is challenging, as the small grains remain in suspension and can form aggregates. In order to look for a footprint of the Anthropocene in Greenland, a sediment core was analyzed to generate a record of MP by comparing a pre- and post-plastic boom period. Using 210Pb and 137Cs dating, the chronology was established from 1861 to 2015 ±5 yrs bridging the plastic boom of the 1950s. Using a 4-step methodology developed for fine-grain matrices, MP particles were characterized via FT-IR imaging. QC/QA protocols were applied throughout the process to reduce the risk of contamination. More than 1000 particles were found in total ranging from 20 µm to 600 µm and going as far back as 1930. Nine polymer types were found, the most common being PE and PP accounting for 84% of all particles. This is the first sediment record of MP pollution in the Arctic, which shows that once thought pristine regions have in fact being polluted for a long time, which in turn implies that the impact might be greater than previously thought. In addition, this long-term accumulation in Greenlandic marine sediment could be compared to global horizons in the search for markers of the Anthropocene.

How to cite: Parga Martinez, K. B., Andersen, T. J., da Silva, V., Strand, J., and Posth, N. R.: Greenland in the Anthropocene: an archive of microplastic pollution, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10534, https://doi.org/10.5194/egusphere-egu23-10534, 2023.

EGU23-11173 | Posters on site | SSP1.4

Comparison Studies for Surface Water Visual Survey and Surface and Water-Column Trawl for Floating and Suspended Marine Plastic Debris 

Won Joon Shim, Yu Lee Jang, Soeun Eo, Jongwook Jeong, Song Yong Ha, Gi Myung Han, and Sang Hee Hong

A visual survey using a vessel is a representative method to assess the degree of pollution of floating plastic debris in marine environments. However, the visual survey may more easily miss plastic items on and just below water (e.g. plastic bags) than above water (e.g. PET bottles). In addition, there are very limited comparison studies for floating plastic debris on the water surface and suspended plastic debris in the water column. None of the studies quantitatively determined the difference in detection rate by visual and surface trawl surveys. The aim of this study is to evaluate what could be relatively missed and underestimated by surface water visual surveys.

Floating plastic debris was monitored by visual and trawl surveys (depth of 0.5 m) in three coastal areas (rural area, GJ; aquafarm area, JH; urban and near river mouth area, SY) of Korea over the four seasons in 2022. In addition, during the visual survey of floating plastic debris in a fishing area (GH), near the river mouth of Han River, a shrimp beam trawl was used to collect plastic debris in the water column (water depth of 10 m) except for thin surface and bottom layer over three seasons in 2022. The seasonal patterns and composition of floating plastic debris in the surface water of JH, GJ, and SY were similar between the visual and trawl surveys. But, the mean densities of most plastics obtained from trawl surveys were 3 to 7 times higher than those from visual surveys. In particular, it was hard to detect small-sized, submerged, or dark-colored fishing gear with the visual survey. Patches with small items can increase the uncertainty of the visual survey. Therefore, visual surveys may underestimate the amount of marine plastic debris above and just below the water.

Various types of floating plastic debris were observed by visual survey in the surface water of GH: plastic bags/sheets (54%), expanded polystyrene pieces (18%), plastic containers (4%), strapping (3%), plastic bottles/caps (3%), discarded fishing gear (1%), and other hard plastic pieces (14%). In the water column of GH, however, plastic bags/sheets (93%) predominated and followed by strapping (4%), discarded fishing gear (1%), and other plastics (1%). These results indicate that plastic bags/sheets and strapping would mainly submerge in the water column, but expanded polystyrene pieces, plastic containers, plastic bottles/caps, and other hard plastic pieces are more likely to float rather than sink. Thus, the application of only visual surveys for plastic pollution monitoring in water may largely miss and underestimate the plastic items transported on and below water such as plastic bags and sheets.

How to cite: Shim, W. J., Jang, Y. L., Eo, S., Jeong, J., Ha, S. Y., Han, G. M., and Hong, S. H.: Comparison Studies for Surface Water Visual Survey and Surface and Water-Column Trawl for Floating and Suspended Marine Plastic Debris, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11173, https://doi.org/10.5194/egusphere-egu23-11173, 2023.

EGU23-12344 | ECS | Posters on site | SSP1.4

The submarine Congo Canyon as a conduit for microplastics to the deep sea 

Florian Pohl, Lars Hildebrandt, Joey O’Dell, Peter Talling, Megan Baker, Fadi El Gareb, Jacopo La Nasa, Francesca De Falco, Marco Mattonai, Sean Ruffell, Joris Eggenhuisen, Francesca Modugno, Daniel Proefrock, Ed Pope, Ricardo Silva Jacinto, Maarten Heijnen, Sophie Hage, Stephen Simmons, Martin Hasenhündl, and Catharina Heerema

The increasing plastic pollution of the world’s oceans represents a serious threat to marine ecosystems and has become a well-known topic garnering growing public attention. The global input of plastic waste into the oceans is estimated to be approximately 10 million tons per year and predicted to rise by one order of magnitude by 2025. More than 90% of the plastic that enters the oceans is thought to end up on the seafloor, and seafloor sediment samples show that plastics are concentrated in confined morphologies and sedimentary environments such as submarine canyons. These canyons are occasionally flushed by powerful gravity-driven sediment flows called turbidity currents, which transport vast volumes of sediment to the deep sea and deposit sediment in deep-sea fans. As such, turbidity currents may also transport plastics present in the canyon and bury plastics in deep-sea fans. These fans may therefore act as sinks for seafloor plastics. Here we present a comprehensive dataset showing the spatial distribution of microplastics in seafloor sediments from the Congo Canyon, offshore West Africa. Multicores taken from 16 locations along the canyon, sampled different sedimentary sub-environments including the canyon thalweg, canyon terraces, and distal lobe. Microplastics were extracted from the sediments by density separation and the polymer type, size, and shape of all individual microplastic particles were analysed using laser-direct infrared-spectroscopy (LDIR). Microplastic number concentrations in the sediments of the distal lobe are significantly higher than in the canyon, indicating that the Congo Canyon system is a highly efficient conduit for microplastic transport to the deep sea. Moreover, microplastic concentrations of >20,000 particles per kg of dry sediment were recorded in the lobe, which represent some of the highest ever recorded microplastic number concentrations in seafloor sediments. This shows that deep-sea fans can serve as hotspots and potential terminal sinks for seafloor microplastics.

How to cite: Pohl, F., Hildebrandt, L., O’Dell, J., Talling, P., Baker, M., El Gareb, F., La Nasa, J., De Falco, F., Mattonai, M., Ruffell, S., Eggenhuisen, J., Modugno, F., Proefrock, D., Pope, E., Silva Jacinto, R., Heijnen, M., Hage, S., Simmons, S., Hasenhündl, M., and Heerema, C.: The submarine Congo Canyon as a conduit for microplastics to the deep sea, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12344, https://doi.org/10.5194/egusphere-egu23-12344, 2023.

EGU23-14119 | ECS | Orals | SSP1.4

Transport and trapping of microplastics in coral reefs: a physical experimental investigation 

Robert Houseago, Freija Mendrik, Christopher Hackney, and Daniel Parsons

Biodiverse coastal ecosystems are vulnerable to microplastic (<5 mm) pollution due to inputs from riverine and shoreline sources which pose ecological threats and have repercussions for social ecosystem services. These ecosystems may contain an aquatic canopy covering the bed, such as seagrass meadows or coral reefs that can trap particles. Despite field measurements revealing the accumulation of plastic debris in a variety of aquatic canopies, the transport and dispositional processes that drive microplastic trapping within such canopies is barely understood. Here, we investigate for the first time the prevalence of biofilmed microplastic retention by sparse and dense branching coral canopies in a hydraulic flume under unidirectional flow. Corals were replicated through 3D-printing using a scan of a staghorn coral Acropora genus, a branching coral that encompasses one-fifth of extant reef-building corals, globally.

Trapping mechanisms by coral canopies were identified, and include: a) interception of particles with the coral acting as a barrier and microplastics and settling to the bed; b) settling of microplastics on the branches or within the structure of the coral and c) accumulation in the downstream region of individual corals. Trapping efficiency was found to depend on bulk velocity and canopy density, with up to 99% of microplastics retained across the duration of the experiments. Surprisingly, sparse reefs may be as vulnerable to microplastic trapping and contamination as denser canopies under certain flow velocities, with the latter found to retain only up to 18% more microplastics than in sparser conditions. Flow velocity profiles provide insights into the relationships between canopy hydrodynamics and microplastic trapping and distribution. The results indicate coral reefs may form areas of accumulation for microplastic pollution through their observed high trapping efficiency that may otherwise have been transported greater distances.

How to cite: Houseago, R., Mendrik, F., Hackney, C., and Parsons, D.: Transport and trapping of microplastics in coral reefs: a physical experimental investigation, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14119, https://doi.org/10.5194/egusphere-egu23-14119, 2023.

EGU23-14286 | ECS | Posters on site | SSP1.4

Paradise lost: Microplastic pollution on a remote coral island, Vietnam 

Freija Mendrik, Christopher Hackney, Vivien Cumming, Nguyen Hung, Sebastian Hennige, and Daniel Parsons

Despite microplastic pollution now being ubiquitous in natural environments, there remains several unknowns in terms of which zones may act as microplastics sinks. Coral reefs are the most ecologically diverse marine ecosystem, supporting 25% of all ocean species, and have high socio-economic value, offering ecosystem services such as coastal protection and tourism. However, the average cover of tropical reefs has declined by 50-75% in nearly all global regions over the last 30-40 years due to a range of anthropogenic stressors. There is growing evidence that coral reefs can entrap plastics and that microplastic (>5 mm) pollution threatens coral physiology. However, there is a lack of understanding as to the occurrence, accumulation, spatial distribution and impacts of microplastic pollution on coral ecosystems. It is, therefore, necessary that more research is undertaken within coral reefs to understand microplastic contamination levels and ensure effective mitigation measures are in place.

The islands of Con Dao, Vietnam, are 90 km from the Mekong Delta coast and are a designated national park, with a 14,000 ha marine protected area that conserves endangered wildlife and a diverse range of coral that support hundreds of fish species. Although considered pristine, Con Dao it is influenced by the Mekong River, which is one of the top contributors to marine plastic waste worldwide, posing an increasing risk to this biodiversity hotspot. Understanding the volumes and impacts of microplastic pollution in this area will allow insight into the levels of exposure and risk coral reefs in Southeast Asia, including the highly biodiverse Coral Triangle, have from increasing plastic pollution.Here, the occurrence and spatial distribution of microplastics in water and sand samples from Con Dao is presented. Reef health is also provided through photogrammetry whereby 3D reconstruction of reef sites allows analysis of coral cover and diversity, in addition to structural complexity, which is strongly correlated to reef health indicators including biodiversity, especially within tropical reef ecosystems. Potential sources of microplastics are also discussed through polymer identification by FT-IR analysis.

How to cite: Mendrik, F., Hackney, C., Cumming, V., Hung, N., Hennige, S., and Parsons, D.: Paradise lost: Microplastic pollution on a remote coral island, Vietnam, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14286, https://doi.org/10.5194/egusphere-egu23-14286, 2023.

EGU23-14881 | ECS | Posters virtual | SSP1.4

Modelling the Uptake and Exchange of Microplastics in Marine Ecosystems using a Novel, Integrated System of High-Resolution Numerical Models 

Róisín Coyle, Jennifer McKinley, Gary Hardiman, Matthew Service, and Ursula Witte

Microplastics (mPs), defined as plastic particles that are less in 5mm in size, are ubiquitous within the marine environment. They are difficult to remove from natural water streams and persist for long periods of time, breaking down into continually smaller particles. Since the diversity of organisms that can ingest plastic particles increases as the particle size decreases, microplastics have been identified as an emerging contaminant of concern in the marine environment and the determination of the potential ecological harm caused by mPs is a key objective of the EU Marine Strategy Framework Directive (MSFD 2008/56/EC). However, the completion of a comprehensive risk assessment of this marine pollutant is prevented by the current lack of consensus on the processes influencing mP transport, uptake and exchange in the marine environment. For example, the processes driving the transport of mPs with buoyant polymers to the deepest part of the ocean are surrounded in uncertainty. The potential for mPs to accumulate within organisms and consequently the significance of trophic transfer as an uptake route for mPs is also unclear, particularly at lower trophic levels where contrasting arguments have formed on the risk of trophic transfer of mPs via zooplankton.

In this study, an integrated system of numerical models has been proposed to improve our understanding of mP processes in the marine environment by simulating the transport and ecosystem uptake and exchange of mPs at lower trophic levels in the northwest European continental shelf region. The continued refinement of the mathematical models will be presented, including the results of tests undertaken to evaluate the efficacy of empirical models for the calculation of the vertical settling velocity of irregularly-shaped particles from the perspective of mP transport modelling. Based on the current availability of data on mP distribution and uptake by lower trophic level organisms in the study area, the feasibility of model implementation will be examined as well as the significance of this research in providing information required by policy makers to complete risk assessment and implement suitable management strategies for marine mP pollution.

How to cite: Coyle, R., McKinley, J., Hardiman, G., Service, M., and Witte, U.: Modelling the Uptake and Exchange of Microplastics in Marine Ecosystems using a Novel, Integrated System of High-Resolution Numerical Models, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14881, https://doi.org/10.5194/egusphere-egu23-14881, 2023.

EGU23-16232 | Orals | SSP1.4

Depositional patterns of microplastics in a meandering river: a case study of the Leie River, Belgium 

Maarten Van Daele, Ben Van Bastelaere, Maaike Vercauteren, Inka Meyer, and Jana Asselman

Following the discovery of microplastics (MPs) in river sediments, the number of MP studies on rivers and other freshwater systems has increased rapidly, revealing that MPs are omnipresent in all freshwater environments. The abundance of MPs in freshwater sediments seems to be affected by population density, urban centers, water flow velocity, water catchment size and position and type of sewage and waste management. However, not all of these relations are consistent. For example, while many studies report good correlations between MP source regions (highly populated and industrialized areas) and MP abundance in river sediments, others do not. This is in contrast to the concentrations in the water itself, for which better links with MP source areas were found. What all these studies have in common, is their large-scale approach, in which sediment samples are obtained over distances of tens to thousands of kilometers along the river; and at each site sediments are than retrieved either from the deepest part of the channel or from the river bank (depending on the study). Here, we study MP distribution in a section of the meandering Leie River, in a rural area, a few kilometers upstream of the city of Ghent (Belgium). Multibeam bathymetry and side-scan sonar images allowed selecting three undisturbed across-channel transects where surface sediments were retrieved. Sediment samples were analyzed for MP content, organic-matter content and grain size of the clastic fraction. Overall the MP concentrations are much (up to an order of magnitude) lower in the thalweg compared to samples near the river banks, resulting in an asymmetric distribution at the bend apex, where the thalweg approaches the outer banks. Furthermore, MP concentrations show strong correlations with the organic matter content and grain-size parameters as expected form hydrodynamic sorting. Exceptions to these correlations are the outer bank samples, where MP concentrations are lower than predicted from sedimentological characteristics. We attribute this to the more erosive character of the current in the thalweg near the outer banks, which inhibits MP deposition, but exposes fine-grained and organic-rich flood plain sediments. We highlight that the different hydrodynamic conditions across a river channel greatly influence MP distribution (with an order of magnitude), but in a sedimentologically predictable manner. Care should thus be taken in environmental studies, as local variability in MP concentration across a river bed may be larger then the large-scale variability.

How to cite: Van Daele, M., Van Bastelaere, B., Vercauteren, M., Meyer, I., and Asselman, J.: Depositional patterns of microplastics in a meandering river: a case study of the Leie River, Belgium, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16232, https://doi.org/10.5194/egusphere-egu23-16232, 2023.

EGU23-66 | ECS | Posters virtual | GD9.1

The time and geodynamics for the final large-scale lateral accretion of the southern Central Asian Orogenic Belt 

Hai Zhou, Guochun Zhao, Yigui Han, Donghai Zhang, and Xianzhi Pei

During Carboniferous time, tremendous juvenile arc crust was formed in the southern Central Asian Orogenic Belt (CAOB), although its origin remains unclear. Our work presented zircon U-Pb-Hf and whole-rock geochemical and Sr-Nd isotopic data for a suite of volcanic and pyroclastic rocks from the Khan-Bogd area in southern Mongolia. These Carboniferous pyroclastic rocks generally have some early Paleozoic zircons, probably derived from the granitic and sedimentary rocks of the Lake Zone and the Gobi-Altai Zone to the north, indicative of a continental arc nature. In addition, they have a main zircon U-Pb age of ca. 370–330 Ma, positive Hf and Nd isotopes, and mafic-intermediate arc affinity, similar to the coeval arc magmatism. Moreover, the pyroclastic rocks of the northern area have more mafic and older volcanic components with depositional time (ca. 350–370 Ma; Visean and Bashkirian stages) earlier than that in the southern area (mainly ca. 350–315 Ma; Serpukhovian and Bashkirian stages). Combining a preexisting northward subduction supported by the available magnetotelluric data with a slab rollback model of the main oceanic basin of the Paleo-Asian Ocean (PAO) during Carboniferous and Triassic times, we infer that the Carboniferous arc magmatism was probably derived from a backarc ocean triggered by slab rollback. Thus, the juvenile arc volcanism of Mongolia, together with other areas (e.g., Junggar) in the southern CAOB, represented a significant lateral accretion that terminated after the Carboniferous due to a significant contraction of the PAO. This research was financially supported NSFC Project (42102260, 41890831, 42072267, and 41972229), Hong Kong RGC GRF (17307918), and HKU Internal Grants for Member of Chinese Academy of Sciences (102009906) and for Distinguished Research Achievement Award (102010100).

How to cite: Zhou, H., Zhao, G., Han, Y., Zhang, D., and Pei, X.: The time and geodynamics for the final large-scale lateral accretion of the southern Central Asian Orogenic Belt, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-66, https://doi.org/10.5194/egusphere-egu23-66, 2023.

EGU23-343 | ECS | Posters on site | GD9.1

Seismicity and active tectonics:  New insights from Sikkim Himalaya 

Mita Uthaman, Chandrani Singh, Arun Singh, Abhisek Dutta, Arun Kumar Dubey, and Gaurav Kumar

The Himalayas, which formed as a result of the impactful collision of the Indian plate with Eurasian plate, is a tectonically complex and seismically active region. It has been a hotspot for many great earthquakes in the past. The continued collision coupled with the complex structural features has led to the persistent seismic activity of the region. The progressive collision led to the formation of distinct tectonic units bounded by thrust faults. The northeastern state of Sikkim in India, which is sandwiched between Nepal and Bhutan in the Himalayas, has been prone to frequent great earthquakes. The deployment of a dense seismic network consisting of 27 broadband seismometers, across Sikkim Himalayas and the northern part of West Bengal, since April 2019 has enabled us to monitor the seismic activity in the study region.

Here, we present a study which aims at understanding the seismotectonic activity of the study region using local earthquakes (epicentral distance < 200km) recorded by the network between April 2019 and September 2022. The progressively improved relocation of local earthquakes recorded in the study region shows a diffuse cloud of micro-seismicity concentrated along a diagonal region extending from north of Assam in the southeast to south of Tibet in the northwest. From south to north we have observed clusters of earthquakes with a gradual increase in their hypocentral depths.

The upper-crustal earthquakes (~0-25km) are located near the down-dip end of the locked part of the Main Himalayan Thrust (MHT), along which India underplates Tibet. We also observe prominent lower crustal earthquakes at depths greater than 30 km. These earthquakes are possibly originating at the junctions of different blocks in an imbricated crust in response to active shortening. We also observe a mid-crustal seismicity pattern following the DCFZ (Dhubri-Chungthang Fault Zone), supporting observations from earlier studies. Striking variations are observed in the faulting mechanisms and orientation of stress axes along the north-south and east-west profiles, and also with depth. We plan to further investigate if these variations imply the presence of possible segmentation, its depth, extent, surface expression and determine its relation to the geodynamics of the region. Integrating the results obtained from the various studies and interpreting them will help in delineating the seismotectonic activity of the study region. Quality data recorded by the dense network will further complement in enhancing the resolution of the results obtained.

How to cite: Uthaman, M., Singh, C., Singh, A., Dutta, A., Kumar Dubey, A., and Kumar, G.: Seismicity and active tectonics:  New insights from Sikkim Himalaya, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-343, https://doi.org/10.5194/egusphere-egu23-343, 2023.

EGU23-349 | ECS | Orals | GD9.1

Cretaceous magmatism from the Sava-Vardar Zone of the Balkans 

Kristijan Sokol, Dejan Prelević, and Ana Radivojević

Кеy words: Upper Cretaceous magmatism, Sava Vardar Zone, Adria, basalts

The complex geodynamic evolution of the northernmost Neotethys is the subject of a long-living controversy. The most perplexing issues are related to the waning stage(s) of the Tethyan ocean(s) in the Balkans and the timing of the Europe-Adria collision. Some authors consider this collision to have occurred in the Late Jurassic, whereas others envisage that have happened at the end of the Cretaceous along the Sava-Vardar Zone. The second model assumes this zone contains a relic suture between Africa- and Europe-derived units.

Late Cretaceous magmatism along the Sava-Vardar Zone includes several centers of small-volume transitional to alkaline Na-basalt (with subordinate rhyolitic rocks) and rare ultrapotassic lavas. This volcanism occurs in both Europe- and Africa- derived units of the collisional zone. The geochemical and isotope compositions of the Late Cretaceous lavas suggest that they are not a part of dismembered ophiolite sequences, but represent intracontinental magmas derived from variably enriched mantle sources. The transitional to alkaline Na-basaltic lavas show a clear “within plate” geochemical signature with typical mantle-like 87Sr/86Sri, 143Nd/144Ndi and 206Pb/204Pbi ratios with relatively high HFSE/LILE ratios, and without orogenic geochemical signatures such as high LILE/HFSE ratios, positive Pb and negative Ti–Nb–Ta anomalies, whereas the ultrapotassic lavas are lamprophyres demonstrating enriched 87Sr/86Sri, 143Nd/144Ndi and 206Pb/204Pbi ratios, LILE enrichment, and orogenic geochemical signatures. A broad range of MREE/HREE ratios in these locations suggests polybaric mantle melting.

Our working melting model is that the mafic melts were generated as a continuum with low-degree melting in the asthenospheric mantle within the garnet stability field and high-degree melting of the freshly metasomatized lithospheric mantle in the spinel stability field. The ultimate trigger of the mantle melting along the Sava-Vardar Zone should be localized extension during transtensional tectonics, in a system of pull-apart basins (Köpping et al., 2019).

Acknowledgments: This research was financed by the Science Fund of the Republic of Serbia through project RECON TETHYS (7744807).

Köopping, J., Peternell, M., Prelevi_c, D., Rutte, D., 2019. Cretaceous tectonic evolution of the Sava-Klepa Massif, Republic of North Macedonia e results from calcite twin based automated paleostress analysis. Tectonophysics 758. https://doi.org/10.1016/j.tecto.2019.03.010.

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How to cite: Sokol, K., Prelević, D., and Radivojević, A.: Cretaceous magmatism from the Sava-Vardar Zone of the Balkans, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-349, https://doi.org/10.5194/egusphere-egu23-349, 2023.

The majestic Himalayan-Tibetan mountains raised due to doubling of the continental crust during the India-Asia collision, which is commonly assumed to occur by under-thrusting of the Indian crust directly below the Asian crust. However, this model implies rheologically weak subducting and upper plate lithospheres and, thus, a collision system that is unable to support a high plateau and whose deformation style is inconsistent with the gross structural and metamorphic architecture of the Himalayan-Tibetan system. Numerical models show that collision between relatively stiffer plates generates strain and metamorphic structures as well as elevations more similar to those observed, but crustal doubling occurs by stacking the subducting crust underneath the rigid upper plate mantle lithosphere. A marked mantellic signature in fluids outflowing the suture zone, the geochemistry of south Tibetan mantle xenoliths, and long wavelength buckling of the Tibetan lithosphere further support the presence of intra-crustal mantle between the Indian and Asian continental crusts. Reconciling the available geophysical evidence with this new model of crustal doubling in the Himalayan-Tibetan range will entail profound implications for our understanding of mountain building during continental subduction and collision.

How to cite: Sternai, P.: Intra-crustal mantle underneath the Himalayan-Tibetan range, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1665, https://doi.org/10.5194/egusphere-egu23-1665, 2023.

EGU23-2259 | Posters on site | GD9.1

Frequency dependent attenuation and relative site response of western Tibet 

Chandrani Singh, Ashwani Kant Tiwari, Eric Sandvol, Shirish Bose, Namrata Jaiswal, Niptika Jana, and Arun Kumar Gupta

We have formulated frequency dependent Lg and Pg attenuation tomographic models to investigate the
crustal Q values and its tectonic implications beneath western Tibet. The frequency dependent
behaviour of both Lg and Pg are studied for the frequency bands of 0.2-0.6, 0.6-1.0 and 1.0-1.4 Hz at
central frequencies of 0.4, 0.8, and 1.2 Hz, respectively, implementing both Two-Station Method
(TSM) and Reverse Two-Station Method (RTSM). The amplitudes of both the waves are fundamentally
sensitive to the crustal structures and are controlled by both scattering and intrinsic attenuation. The
frequency dependent characteristics of QLg and QPg are consistent in nature for the region. Moderate to
high Q values evident in the Lhasa terrane could supplement the trace of underthrusting Indian
lithosphere beneath the region. The average Q values for both Lg and Pg increase with increasing
frequency. The frequency dependent parameter η shows quite high values, for both the waves using
TSM and RTSM, which may indicate strong heterogeneities present in the crust. Subsequently, relative
site responses at each station are studied using RTSM for the central frequencies of 0.4, 0.8, and 1.2
Hz. Weak to negative site responses are mostly dominant in western Tibet. Relative site responses are
found to vary with frequency which could be associated with the sampling depth. We found no
correlation of site responses with the elevation.

How to cite: Singh, C., Tiwari, A. K., Sandvol, E., Bose, S., Jaiswal, N., Jana, N., and Gupta, A. K.: Frequency dependent attenuation and relative site response of western Tibet, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2259, https://doi.org/10.5194/egusphere-egu23-2259, 2023.

EGU23-2463 | Posters on site | GD9.1

Seismic constraints on the nature and geometry of the downwelling Indian crust beneath Sikkim Himalaya 

Arun Singh, Gaurav Kumar, Chandrani Singh, M. Ravi Kumar, Mita Uthaman, Dipankar Saikia, and Arun Kumar Dubey

  The exact role of subducting Indian continental crust in the formation of Himalaya-Tibet collision zone remains enigmatic. The mass budget estimates describing shortening across the orogen is partly derived from the observations made from seismic imaging of deep earth. Here using data from 38 broadband seismic stations covering Sikkim Himalaya, we produce high resolution seismic images in order to fill the crucial gaps in our understanding of the formation of Himalayan collision zone. We have used 11,594 high quality receiver functions using earthquakes of magnitude >5.5 in the distance range of 30-100°. Our data demonstrates a highly imbricated and heterogeneous crust beneath Sikkim Himalaya. The Main Himalayan thrust responsible for large scale earthquakes in the Himalayan collision zone is not so vivid in the migrated images, but is observed intermittently. The main cluster of earthquakes at shallower depths linked to the Main Himalayan thrust is marked by low amplitude arrivals. Overall trend suggests a gently dipping Moho attaining crustal depths of ∼60 km beneath Higher Himalaya compared to ∼40 km in the Himalayan foredeep. Moho as we see in this segment of Himalaya is with possible offsets and overlapping segments. Imbrication is well reported in the Himalayan orogenic wedge forming upper crust, we also observe this in the lower crust indicating lithospheric imbrication in response to collision. Interestingly, the lower crustal clusters of earthquakes fall at the juncture of offsets in the Moho. The offset positions at lower crustal depths seem more prone to earthquakes in response to active shortening. Seismic images reveal differences in amplitude of receiver functions and presence of conversions at deeper depths in the lithospheric mantle across Dhubri-Chungthang Fault Zone, possibly related to the segmentation of Himalaya.  

How to cite: Singh, A., Kumar, G., Singh, C., Kumar, M. R., Uthaman, M., Saikia, D., and Dubey, A. K.: Seismic constraints on the nature and geometry of the downwelling Indian crust beneath Sikkim Himalaya, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2463, https://doi.org/10.5194/egusphere-egu23-2463, 2023.

EGU23-2521 | Orals | GD9.1

Early Indosinian magmatism in the West Qinling orogen and its tectonic implication 

Meng Wang, Xianzhi Pei, Zuochen Li, Ruibao Li, Lei Pei, Youxin Chen, Chengjun Liu, and Shaowei Zhao

The West Qinling Orogen (WQO), which is bounded by the Qilian Orogenic Belt, Qaidam Block and the Songpan-Ganzi Block, is the western extension of the Qinling Orogenic Belt, and experienced complex tectonic evolution processes, involving the opening, subduction and closure history of the Proto- and Paleo-Tethys Oceans. The WQO features widespread Indosinian magmatic rocks, which are crucial to constrain the tectonic evolution of the WQO. The Indosinian magmatic rocks were formed mainly in two stages, 250 to 240 Ma and 225 to 210 Ma. The Early Indosinian magmatic rocks (250 to 240 Ma) are mainly distributed in the west and middle northern WQO. In comparison, the Late Indosinian magmatic rocks are mainly exposed in the eastern WQO, but also in the western WQO and the Bikou terrane. Controversy has existed for a long time on the petrogenesis and tectonic setting of the Early Indosinian magmatic rocks. We selected four respective plutons, including the Heimahe pluton, the Ren’ai pluton, the Daerzang pluton and the Ganjiagongma pluton. Detailed field investigation, petrology, LA-ICP-MS zircon U-Pb dating, zircon Lu-Hf isotope analyses, whole rock geochemistry and Sr-Nd isotope analyses, and mineral EPMA analyses were conducted for the studied plutons. The studied plutons were emplaced between 246 to 241 Ma according to zircon U-Pb dating results. Based on detailed studies on petrology, geochronology and geochemistry, we emphasis the significance of magma mixing in the petrogenesis of the Early Indosinian granitic rocks. The high Mg# signature of the Early Indosinian granitic rocks were generated by magma mixing between mafic and felsic magmas, but not result of direct fractional crystallization of mafic rocks. The granitic rocks with high Sr/Y values in the WQO, represented by the Ganjiagongma pluton, were not derived from thickened continental crust. No evident continental thickening occurred in the WQO during the Early Indosinian. Combining with regional geological evidence, we propose an alternative tectonic model to explain the evolution history of the WQO during the early Mesozoic. The A’nimaque-Mianlue ocean subducted northward with low angle, then the subducted slab rolled back during the Late Permian to Middle Triassic, and the ocean closured in the Late Triassic. This model can explain the spatial and temporal distribution characteristics of the magmatic rocks and sedimentary rocks, as well as Late Triassic uplift and deformation event in the WQO.

How to cite: Wang, M., Pei, X., Li, Z., Li, R., Pei, L., Chen, Y., Liu, C., and Zhao, S.: Early Indosinian magmatism in the West Qinling orogen and its tectonic implication, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2521, https://doi.org/10.5194/egusphere-egu23-2521, 2023.

EGU23-2622 | Orals | GD9.1

Synced deformation of the Talesh-Alborz-Kopet Dagh belt and formation of the Iranian Plateau 

Yang Chu, Bo Wan, Ling Chen, Wei Lin, Morteza Talebian, Xiaofeng Liang, and Liang Zhao

Plate convergence has continued for over 25 Myr after the Arabia initially collided with the Eurasia, causing vast intracontinental deformation within the Central Iran Block at the southern margin of the Eurasia. During the same period, the Iranian Plateau grew as tectonic stress from continental collision propagated northwards, accompanied by strong deformation, crustal shortening and rapid rock exhumation, but the process of the plateau formation remains less discussed. From west to east, the Talesh-Alborz-Kopet Dagh (TAK) situates at the northern front of the Iranian Plateau and suffers intense folding and thrusting that creates the highest mountain range in Iran, so its tectonic evolution history carries important clues for the building of the current plateau.

To better constrain the spatial and temporal patterns of deformation and exhumation, we carried out comprehensive structural analysis and new geochronology-thermochronology dating for the TAK. As a first order feature of the collision zone, the TAK records an immediate response to the initial collision. Oligocene deformation is well documented but unevenly exhumed different segments of the belt along-strike. The Talesh and westernmost Alborz preserves late Neoproterozoic basement rocks (~570 Ma) and old, Mesozoic zircon U-Th/He ages (150-90 Ma), acting as a relatively rigid part resistant to Oligocene deformation. In contrast, the main part of Alborz was remarkedly shortened by folds and thrusts and exhumed rapidly, while the Kopet Dagh shows a simply folded belt dominated by box folds in deca-kilometer scale. All the TAK experienced enhanced exhumation since 20 Ma, peaked at the Late Miocene, suggesting the deformation was synced around 7 Ma when the internal tectonic organization along the belt and within the Central Iran Block had been much reduced. This Late Miocene switch reflects a reorganization of Arabia-Eurasia plate convergence. The causes could include that elevation increased to a level at which the Iranian Plateau was built and resisted further thickening, or internal heterogeneity was decreased and the whole region began to evolve as a single tectonic unit, causing deformation to be accommodated in other regions. The growth model of Iranian Plateau can also enlighten us on how Tibetan Plateau developed and expanded at its early stage.

How to cite: Chu, Y., Wan, B., Chen, L., Lin, W., Talebian, M., Liang, X., and Zhao, L.: Synced deformation of the Talesh-Alborz-Kopet Dagh belt and formation of the Iranian Plateau, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2622, https://doi.org/10.5194/egusphere-egu23-2622, 2023.

EGU23-3799 | Orals | GD9.1

NW Iran under pressure: Cristallization and metamorphic ages of the Shanderman eclogites. 

Daniel Pastor-Galán, Tatsuki Tsujimori, Alicia López-Carmona, and Keewook Yi

The Tethyan oceans are the internal sotry-tellers of the amalgamation, tenure and break up of Pangea. All tethyan oceans have been mostly consumend and only remnants of them occur now along the margins of the Atlantic, Mediterranean, Black and Caspian seas, as well as in the Alpine-Himalayan and adjacent orogens. The Rheic (~500 to ~300 ma, some-times Ran or Proto-Tethys) closed during the amalgamation of Pangea and the Neo-Tethys (~270 to ~20 ma) is the main witness of its break-up. The Paleotethys is the ocean that shared an internal position during most of Pangea’s tenure. There is no consensus about its origin, some suggest that opened during the latest stages of Pangea’s amalgamation (Devonian-Carboniferous) whereas others considert it a remnant of the mostly subducted Rheic ocean after Gondwana-Laurussia collision.

We have studied the Shanderman eclogites (NW Iran) and put them into their context within other HP rocks in the area because they a potential candidate to represent the Paleotethys ocean. They are metamorphosed oceanic rocks (protolith oceanic tholeiitic basalt with MORB composition). Eclogite occurs within a serpentinite matrix, accompanied by mafic rocks resembling a dismembered ophiolite. The eclogitic mafic rocks record different stages of metamorphism during subduction and exhumation.

In this contribution we will show the new petrological, geochemical and geochronological results from this eclogites to shed light on the evolution of the tethyan oceans during the Paleozoic. The protolithic oceanic crust of Shanderman crystallized ~350 Ma, metamorphic age suggest that this piece of ocean subducted soon after forming, representing, perhaps, a subduction initiation or a ride-subduction event. We also found a metasomatic event at ~280 ma. Considering its relation with other HP rocks in Iran, we interpret that the Shanderman ophiolites are not a fragment of the Paleotethys but a fragment of the Rheic (Ran/Prototethys) ocean.

How to cite: Pastor-Galán, D., Tsujimori, T., López-Carmona, A., and Yi, K.: NW Iran under pressure: Cristallization and metamorphic ages of the Shanderman eclogites., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3799, https://doi.org/10.5194/egusphere-egu23-3799, 2023.

EGU23-3845 | Posters on site | GD9.1

Orogenic Gold Mineralization and its Relationship to Tectonic Evolution of the Kalamaili Area, East Junggar, Northwest China 

Xuexiang Gu, Yongmei Zhang, Zhanlin Ge, Weizhi Chen, and Liqiang Feng

There are many lode gold deposits and occurrences in the Kalamaili area of the East Junggar, Northwestern China. The deposits are confined to a narrow zone between the regional NW- to NWW-trending Kalamaili and Qingshui-Sujiquan shear zones and are structurally controlled by secondary, high-angle faults of the regional shear zones. The orebodies occur in the Middle Devonian and Lower Carboniferous strata that are largely composed of zeolite to lower greenschist facies clastic sedimentary and pyroclastic rocks. Gold mineralization occurs as auriferous quartz-sulfide±tourmaline veins/veinlets and disseminated ores in the immediate altered wall rocks. The ore mineralogy is relatively simple and dominated by quartz with minor to trace amounts of sulfides (pyrite and arsenopyrite, typically <5% in volume), sericite, calcite, and gold. The hydrothermal alteration halos are characterized by a proximal, 0.5–5 m wide zone composed mainly of quartz-sericite (-tourmaline)-sulfide (-gold) and a distal, several to tens of meters wide zone with a calcite-chlorite-epidote assemblage. Hydrothermal processes essentially involve a pre-ore stage of barren quartz, a main-ore stage of quartz-sulfide-gold (±tourmaline), and a post-ore stage of barren quartz-calcite (±sericite).

Fluid inclusion microthermometry, stable isotopes, and hydrothermal zircon U-Pb dating were combined to constrain the nature and source of ore fluids, the timing of mineralization, and the mechanism of gold precipitation. The ore-forming fluid of the main-ore stage is uniformly characterized by a medium to high homogenization temperature (mostly 240° to 330℃), low salinity (typically <6 wt % NaCl equiv), reduced, and CO2-rich-H2O-NaCl±CH4 fluid. The hydrogen and oxygen isotope data (δ18OH2O=+8.4 to +17.3‰, δDH2O=–99 to –62‰) indicate a metamorphic origin for the mineralizing fluid. The majority of δ34S values of the sulfides range between 0 and +10‰ with a mean of +2‰ (n=62), indicative of a largely sedimentary rock reservoir of sulfur in the ore-forming fluids. LA-ICP-MS U-Pb isotope dating of the hydrothermal zircons from auriferous quartz veins yielded a weighted mean 206Pb/238U age of ~313 Ma.

Combined geological and geochemical evidence indicates that the transition from compressional to transcurrent deformation during the late- to post-orogeny in the late Carboniferous played a vital role for the gold-bearing fluid flow along regional shear zones and subsequent channeling into the second- and third-order faults. On a deposit scale, fault-valve behavior during seismic fault activity is a key mechanism that caused episodic changes in fluid pressure and the resultant phase separation of ore fluids and precipitation of gold. Sulfidation of wall rocks due to fluid-rock interaction is another important mechanism for the gold precipitation. Later since the Permian, the N-S compression resulted in uplift and exhumation of the East Junggar terrane and deformation of the orebodies. Target gold exploration in this region is suggested to focus on the northeast side of the Kalamaili fault zone, where there exist suitable faults that connect with the first-order fault zones at depth and lead to focused fluid flux into depositional sites at shallower levels.

How to cite: Gu, X., Zhang, Y., Ge, Z., Chen, W., and Feng, L.: Orogenic Gold Mineralization and its Relationship to Tectonic Evolution of the Kalamaili Area, East Junggar, Northwest China, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3845, https://doi.org/10.5194/egusphere-egu23-3845, 2023.

Epithermal base and precious veins are typically structurally controlled, and structures are fundamental to fluid flow and mineralization in hydrothermal deposits. In recent mineral explorations in east Kerman, especially in the northeast of the Shahr-e Babak area, it was found that structures play a key role in the mineralization of epithermal gold deposits. Shahr-e Babak epithermal gold deposit is located at 30°27'54.80'' N, 54°31'47'' E in the southeast of the Sanandaj Sirjan Zone, east of Kerman. The lithological outcrops of the Shahr-e Babak deposit area consist of Cretaceous felsic to mafic intrusive and extrusive rocks, Eocene micrite limestone and sandstone intruded by hornblende diorite, granodiorite, and microgranite stocks and dykes. Gold mineralization with an average grade of 1.5 g/t, is associated with anomalous Ag, Mo, Pb, and Sb and is usually concentrated in jasperoids with argillic and silicification alteration halos which are < 120 m in length and average about 10 m in width within east-west trending structures.  

The Shahr-e Babak deposit area is located in a restraining bend of the Shahr-e Babak fault. There is a strike-slip duplex and E-W trending fault lens with an approximate 5×7 kilometers area related to the young movements of the Shahr-e Babak fault. For these reasons, the rocks in the deposit area have been ruptured and crushed which are not associated with extensive hydrothermal alterations. According to measurements, faults can be divided into three main groups. The first group is the main faults with 80–90-degree trending, the second group consists of faults with 100–120-degree trending and the last category is minor faults with NE-SW and NW-SE trending. A combination of field observations, measurements of faults and fractures, and drill core logging indicates that gold-bearing jasperoids are formed along strike-slip faults with a 100–120-degree trend in lens-shaped fault zones that change in thickness with depth. 

The recent discovery of the Shahr-e Babak epithermal gold deposit, located on a restraining bend of the Shahr-e Babak fault, highlights the exploration potential for epithermal gold mineralization in East Kerman. In addition, undiscoverable epithermal gold deposits may be hidden below the regionally extensive Quaternary cover.

How to cite: Shafiee, S., Niroomand, S., and Soleymani, M.: Identifying the Role of Structures in the Mineralization of Shahr-e Babak Epithermal Gold Deposit: Implications for Epithermal Gold Exploration in East Kerman, Southeastern Iran, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3961, https://doi.org/10.5194/egusphere-egu23-3961, 2023.

High-pressure and ultrahigh-pressure minerals tend to be preserved in mafic and ultramafic metamorphic rocks, such as eclogites and garnet amphibolites, rather than felsic rocks. Generally, the garnet amphibolites preserve particular porphyroblastic and corona textures that provide important information of geological processes. Therefore, identification of garnet amphibolite might hint that subduction or collision processes were likely to have occurred.

The Yili Block is one microcontinent in southwest of Central Asian Orogenic Belt, with Precambrain basement rocks exposed in the northern and southern margin. The Middle to Late Ordovician arc-type magmatic rocks were identified in the northern margin of the Yili Block with a subduction-related calc-alkaline affinity infer that the southward subduction of the Junggar Ocran beneath the Yili Block, but the record of coeval metamorphism is rarely reported. The Toksai garnet amphibolites idientified from the Wenquan Group in the northern margin of Yili Block records a clockwise P-T-t path. Its near isothermal depressive retrogressive metamorphism was typical characteristic of the Western Alps P-T path, recording the process of subduction and collision. The protolith belongs to tholeiite, with high TiO2 and low K2O+Na2O contents (3.10~3.89 wt.%, 0.76~2.01 wt.% respectively), enrichment of large ionic lithophile elements and depletion of high field strength elements, and enrichment of rare earth elements, showing the geochemical characteristics of tholeiite in intra-continental rift setting (Th/Ta=1.70~2.76, Ta/Hf=0.23~0.37). The geochemical characteristics reveal that the magmatic rocks derived from an OIB-like mantle source. The garnet amphibolites also has low contents of MgO (4.82~6.40 wt.%), Cr (70.8~224 ppm), Ni (9.68~65.7 ppm) and low values of Mg# (34.0~41.3), Nb/U (14.3~36.3), Nb/Ta (9.70~16.2), indicating that their protolith are not primitive magma, were formed by separate crystallization of different mineral phases with a small amount of crustal contamination. The zircon U-Pb dating results suggest that the garnet amphibolites protolith was formed in the middle to late Neoproterozoic, and the metamorphic age is end of Late Ordovician (450~440 Ma). The zircon and monazite from surrounding rocks also record the coeval tectonic thermal event. Consequently, it is inferred that the protolith of the garnet amphibolites may have formed in an intraplate rifting setting as a result of the breakup of Rodinia, and indicating that the Yili Block maybe a continental fragment separated from the Tarim Block during the middle to late Neoproterozoic. In the Middle to Late Ordovician, the Wenquan Group as a part of Aktau-Wenquan contineantal domain was involved in the continental–arc collision and continuing accretion in north of the Yili/Kazakhstan Block with the southward subduction of the Junggar–Balkhash oceanic lithosphere, and experience high amphibolite facies metamorphism in the end of Ordovician.

How to cite: Chen, Y., Wang, M., and Pei, X.: Chronology, geochemistry, metamorphic evolution and its tectonic implications of the Toksai garnet amphibolites in the northern margin of Yili Block, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4041, https://doi.org/10.5194/egusphere-egu23-4041, 2023.

EGU23-4091 | ECS | Orals | GD9.1

Late Mesozoic continental arc in East China Sea: Constraints from detrital zircons 

Yuling Deng and Changhai Xu

The Late Mesozoic subduction of Izanagi beneath East Asia formed large-scale intraplate magmatism in SE China and subduction mélanges from SW Japan to eastern Taiwan (Müller et al., 2016; Wang et al., 2008; Wakita and Metcalfe, 2005), but the accompanying arc remains uncertain. The East China Sea (ECS) is settled between the intraplate and trench, in which previous studies have found some arc indications (Xu et al., 2017). ECS domains share a unified basement with, or are regarded as an exotic microcontinent of Cathaysia block, which is still up for debate.

Discerning delta facies and litharenite types of sediment samples support a typical proximal environment of Lishui-Jiaojiang sag, SW ECS. As its provenances, nearby Zhemin and Yandang swells provide Late Mesozoic voluminous felsic suites with minor metabasite materials. We conducted LA-ICP-MS U-Pb zircon dating and trace element analyses of proximal sandstones in the SW ECS to track a Jurassic to Cretaceous magmatic arc, which advantages over the use of a few drilled igneous rocks. Newly acquired data reveal an evolved magmatic arc in SW ECS from Jurassic to Cretaceous (200–86 Ma), which developed predominantly in episodes of 150–124 Ma and 124–102 Ma. Arc magmatism exhibits characteristics of low-T and continental zircon types, yielding high Th/U, U/Yb, Sc/Yb, and Th/Nb ratios and low Nb/Yb and Nb/Hf ratios. Trace elements U and Th in arc zircons indicate a decline in subduction fluids addition due to slab rollback and a rise in lower crustal addition owing to fluid-fluxed crustal melting from Jurassic to Cretaceous.

The swells of Yushan, Zhemin, Haijiao, and Hupijiao outline a Late Mesozoic magmatic arc in the West ECS. This magmatic arc, in conjunction with the SE China intraplate, and subduction mélanges, spatially forms a Late Mesozoic trench-arc-intraplate architecture in response to the Izanagi subduction beneath East Asia. Its identified tectonic scenarios mainly include slab strike-slip subduction (200–170 Ma), slab stagnation and intraplate foundering (170–150 Ma), slab rollback and removal of the thickened arc root (150–102 Ma), and trench retreat with arc migration (102–86 Ma). Detrital zircon data suggest that the West ECS and Cathaysia block share a unified basement that formed at ca. 2.44 Ga and ca. 1.85 Ga, which was reworked at ca. 780 Ma, ca. 442 Ma, and ca. 240 Ma. The West ECS magmatic arc evolved on this Cathaysia-type basement.

Keywords: magmatic arc; detrital zircon; Late Mesozoic; Izanagi subduction

 

 

Müller, R.D., et al., 2016. Ocean basin evolution and global-scale plate reorganization events since Pangea breakup. Annual Review of Earth and Planetary Sciences, 44(1), 107138.

Wakita, K., and Metcalfe, I., 2005. Ocean plate stratigraphy in East and Southeast Asia. Journal of Asian Earth Sciences, 24(6), 679–702.

Wang, Y.J., et al., 2008. Sr-Nd-Pb isotopic constraints on multiple mantle domains for Mesozoic mafic rocks beneath the South China Block hinterland. Lithos, 106(3–4), 297–308.

Xu, C.H., et al., 2017. Tracing an Early Jurassic magmatic arc from South to East China Seas. Tectonics, 36, 466–492.

How to cite: Deng, Y. and Xu, C.: Late Mesozoic continental arc in East China Sea: Constraints from detrital zircons, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4091, https://doi.org/10.5194/egusphere-egu23-4091, 2023.

EGU23-4201 | ECS | Orals | GD9.1

Reassessment of the Phanerozoic net crustal growth: U–Pb and Hf zircon data for the Central Asian Orogenic Belt 

Ariuntsetseg Ganbat, Tatsuki Tsujimori, Daniel Pastor-Galán, and Alexander Webb

The Central Asian Orogenic Belt (CAOB) consists of several continental blocks, was assembled during the Phanerozoic, and preserves large volumes of Phanerozoic granitoids with juvenile Nd and Hf isotope characteristics, and thus regarded as the largest site of Phanerozoic continental growth on Earth. Nonetheless, it remains disputed whether the significant crustal additions occurred during the Phanerozoic. We compiled available zircon U–Pb geochronological and Hf-in-zircon isotopic data for granitoids from the orogenic segments of CAOB. Using this data, we estimated the percentage of juvenile versus evolved crustal portions in different Phanerozoic time slices of the CAOB.     

The areal distribution of Hf isotopic information shows a younging trend in the Hf model age and radiogenic Hf values from northeast to southwest. For many orogenic segments of the CAOB, the range of hafnium isotope signatures for the granitoids shifted towards more radiogenic compositions over time. We interpret these findings to indicate that the lower crust and lithospheric mantle beneath the CAOB continental blocks were largely removed during continuous oceanic subduction and replaced by juvenile crust. Melts of this crust display the radiogenic hafnium signature. The juvenile versus evolved crustal portion estimations in different time slices show that the crustal growth has taken place in a steady-state mode, and the rate of the radiogenic crustal generation is close to overall global averaged rates of crust generation. It follows that Phanerozoic net crustal growth in accretionary orogens, as exemplified by the CAOB, may have been overestimated as it has been compensated by crustal destruction.

How to cite: Ganbat, A., Tsujimori, T., Pastor-Galán, D., and Webb, A.: Reassessment of the Phanerozoic net crustal growth: U–Pb and Hf zircon data for the Central Asian Orogenic Belt, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4201, https://doi.org/10.5194/egusphere-egu23-4201, 2023.

EGU23-4461 | Posters on site | GD9.1

Thermochronologic constraints on exhumation associated with the Main Pamir Thrust 

Edward Sobel, Jonas Kley, Johannes Rembe, Rasmus Thiede, Johannes Glodny, Lennart Grimm, Maximilian Rometsch, Asil Newigy, Nowrad Ali, Wafaa Altyeb, and Daniela Espinoza Tapia

The Pamir orogen forms the northwest prolongation of the Tibetan plateau. The most important surficial structure bounding the northern and northwestern margin is the Main Pamir Thrust (MPT); however, despite the importance of the structure, surprisingly little is known about the displacement history of the fault. Together with the younger, foreland-oriented Pamir Frontal thrust system (PFT), displacement estimates range from 50 to over 300 km. The larger estimates are based on the estimated Cenozoic northward indentation of the Pamir with respect to Tibet as well as the length of the intracontinental Pamir seismic zone. However, recent work suggests that some of the indentation predates the Cenozoic or is related to an original Paleozoic embayed paleogeography and other studies have suggested that the seismic zone is not related to intracontinental subduction. Shortening estimates in the hanging walls of the MPT and PFT suggest more modest amounts: between 30 and 75 km in the north, with higher values for SE-NW shortening in the Tadjik depression.

Constraining the onset of deformation has proven challenging. Most publications suggest a late Oligo-early Miocene onset age. Cenozoic stratigraphic sequences are unfossiliferous and poorly dated. We have attempted to resolve this question by collecting samples for thermochronologic analysis from many locations along the arcuate margin. In general, zircon (U-Th-Sm)/He (ZHe) samples yield ages between ~60 and 17 Ma. Many are likely to be partially reset. Ages are slightly older in the east, which could reflect an overall westward increase in exhumation. The relatively small amount of exhumation in the north supports our structural interpretation that the MPT there has a low dip angle and might not have produced pronounced topography. Apatite fission track (AFT) and apatite (U-Th-Sm)/He (AHe) are often much younger; often between <15 and 10 Ma in the MPT hanging wall and < 10 Ma in the footwall. These younger ages may reflect the activation of a second pulse of exhumation linked to motion along the PFT. We are modeling these data sets using QTQt to try to better constrain the exhumation history of the fault system. In turn, these should help constrain shortening estimates.

How to cite: Sobel, E., Kley, J., Rembe, J., Thiede, R., Glodny, J., Grimm, L., Rometsch, M., Newigy, A., Ali, N., Altyeb, W., and Espinoza Tapia, D.: Thermochronologic constraints on exhumation associated with the Main Pamir Thrust, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4461, https://doi.org/10.5194/egusphere-egu23-4461, 2023.

The active deformation field between northern Tibet and central Mongolia is dominated by diffuse sinistral transpressional reactivation of the southern Altaids Phanerozoic terrane collage.   The angular relationship between NE-directed SHmax and pre-existing basement trends is the dominant control on Quaternary fault kinematics.  Along Tibet’s northern margin, the Altyn Tagh system is widening northwards by transpressional duplexing.  The Nanjieshan and Sanweishan comprise sinistral oblique-slip thrust ridges within a regional asymmetric flower structure centered on the Altyn Tagh Fault.  In the southern Beishan, interconnected lensoidal domains of transpressional and transtensional faulting are subtly indicated by Quaternary fault scarps, low-relief rejuvenated landscapes and alluvial sedimentation.  The SE Beishan and western Hexi Corridor region contain numerous Late Quaternary fault systems including the Heishan-Jinta'Nanshan sinistral strike-slip corridor and the Helishan-Longshoushan fault array that connects eastwards with the transtensional grabens of the Yabrai and Langshan in the eastern Alxa Block.  Further north, the Paleozoic terrane collage of the Gobi Corridor was repeatedly reactivated during the Permo-Triassic, Jurassic, Cretaceous and Neogene.  Late Cenozoic reactivation was likely facilitated by thermal weakening of the crust due to Jurassic-Miocene volcanism, and diffuse Cretaceous rifting and crustal thinning.  Although terrane boundaries and other faults are reactivated in many areas, thrust and oblique-slip reactivation of WNW striking shallowly dipping sedimentary bedding and metamorphic fabrics is equally important.  Conversely, modern E-W trending strike-slip faults in the Gobi Altai typically crosscut older basement trends. In the Altai and Gobi Altai, the Late Cenozoic fault array has created a transpressional  basin and range physiographic province.  Coalescence of separate ranges into topographically continuous mountain belts in the Altai, Gobi Altai and easternmost Tien Shan is an important mechanism of transpressional mountain building not predicted by classical plate tectonic models.  Throughout the vast deforming region north of Tibet, tectonic loading is shared amongst a diffuse fault network challenging assumptions about earthquake recurrence intervals and seismic hazard forecasting.

How to cite: Cunningham, D., Yang, H., and Zhang, J.: Late Cenozoic Crustal Reactivation of the North Tibetan Foreland, Western Hexi Corridor, Beishan, and Gobi Corridor: Implications for Intraplate Fault Networks, Mountain Building Processes and Earthquake Hazards in Slowly Deforming Regions of Central Asia, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4597, https://doi.org/10.5194/egusphere-egu23-4597, 2023.

EGU23-4737 | ECS | Posters on site | GD9.1

Geophysical evidence of large-scale silica-rich fluid flow above the continental subduction interface 

Yuantong Mao, Liang Zhao, Marco Malusà, Stefano Solarino, Silvia Pondrelli, Baolu Sun, Coralie Aubert, Simone Salimbeni, Elena Eva, and Stéphane Guillot

Continental subduction zones are crucial tectonic settings where subducted slabs exchange crustal materials with the mantle, and geochemical changes occur with the participation of fluids at increasing temperatures and pressures. The occurrence of pervasive networks of quartz veins in exhumed sections of the Alpine subduction wedge provides evidence for major silica-rich fluid circulation in the shallowest levels of the subduction zone. However, the occurrence of silica-rich fluids at greater depths above the subduction interface remains speculative.

Rocks involved in the subduction zone experience variable temperature and pressure conditions and show a wide range of densities and seismic velocities that are not necessarily correlated. An integrated analysis of seismic velocities, Vp/Vs ratios and rock densities may provide a viable tool to detect compositional variations in the Earth’s interiors and infer the impact of large-scale fluid flows on the intrinsic physical properties of subducted rocks. We tackle this issue from a geophysical perspective, by applying H-κ stacking, receiver function analysis, and waveform and gravity modelling. We found a belt of high Vp/Vs ratios >1.9 in the rear part of the Alpine subduction wedge, consistent with a partly serpentinized upper-plate mantle, and a belt of unusually low Vp/Vs ratios <1.7 in the frontal part of the subduction wedge that we interpret as the effect of a pervasive network of silica-rich veins above the subduction interface. Laboratory experiment shows that Vp/Vs ratios are generally higher for serpentinite (2.0-2.2), and much lower for quartz (1.46-1.48).

Our results suggest a dominant role of silica-rich fluids in the subduction wedge. These silica-rich fluids rose within the subduction wedge until the change in ambient conditions precipitated the formation of a widespread network of quartz veins, as observed in the field. And this pervasive quartz-vein network changes the physical properties of the subduction-wedge rocks, implying a major impact on rheology favoring crustal deformation during continental subduction.

How to cite: Mao, Y., Zhao, L., Malusà, M., Solarino, S., Pondrelli, S., Sun, B., Aubert, C., Salimbeni, S., Eva, E., and Guillot, S.: Geophysical evidence of large-scale silica-rich fluid flow above the continental subduction interface, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4737, https://doi.org/10.5194/egusphere-egu23-4737, 2023.

EGU23-5179 | Posters on site | GD9.1

New constraints on the geological evolution of the SE corner of the Arabian Plate (NE Oman) 

Wilfried Bauer, Joachim Jacobs, Ivan Callegari, Andreas Scharf, and Frank Mattern

The Saih Hatat Dome is a tectonic window in northeastern Oman with a NW-SE extension of <95 km and an E-W extension of <50 km, rimmed by the allochthonous Samail Ophiolite and the underlain nappes composed of sedimentary rocks from the Neo-Tethyan Hawasina Basin. Rocks within the window were affected by an upper Cretaceous high- to ultra-high pressure/low-temperature eclogite- and blueschist-facies metamorphism.

Stratigraphically, the Saih Hatat Dome contains a several kilometer thick basal (“Autochthonous A”) sequence from what is believed Cryogenian Hatat schists to the Ediacaran Hiyam dolostone, unconformably overlain by 3400 m Cambro-Ordovician siliciclastics. This basal sequence is separated by a so-called ‘Hercynian’ unconformity from Permian to Jurassic overall shelf carbonates (“Autochthonous B”). In the eastern part of the window, intense Cretaceous deformation and metamorphism makes it difficult to identify this stratigraphic subdivision.

New U-Pb zircon LA-ICP-MS data from a quartzdiorite dyke, intruding the basal part of the Hatat schists gave a crystallization age of 845 +2/-4 Ma. Thus, the basal part of the Hatat schists is Tonian in age and older than the Cryogenian/Ediacaran strata of the nearby Jebel Akhdar Dome and Huqf area, 40 km to the west and 300 km to the south, respectively.

Two blueschist-facies tuffites from eastern Saih Hatat contain concordant detrital zircons, ranging in age between c. 530 and 2872 Ma with age clusters around 750 to 850 Ma and 1010 to 1164 Ma. The latter ages are not known from a source on the Arabian Plate and might be derived from an Indian source.

Based on the new results, we suggest a subdivision of the Saih Hatat stratigraphy with a Tonian accretionary wedge (Hatat schist) which might be coeval with igneous intrusion from the Ja’alab area, an Ediacaran carbonate platform, and a Cambrian sedimentary basin, unconformably overlain by upper Cambrian/Ordovician quartzites.

How to cite: Bauer, W., Jacobs, J., Callegari, I., Scharf, A., and Mattern, F.: New constraints on the geological evolution of the SE corner of the Arabian Plate (NE Oman), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5179, https://doi.org/10.5194/egusphere-egu23-5179, 2023.

EGU23-5946 | ECS | Posters virtual | GD9.1

Slab geometry and a diffuse plate boundary beneath Sumatra: constrained using a new receiver function analysis method 

Mingye Feng, Ling Chen, Shengji Wei, Xin Wang, Xu Wang, and Zimu Wu

Geometry and structure of the subducting plate boundary are key to understanding geodynamic processes of subduction and related geological phenomena. Located between the obliquely converging Indo-Australian and Sunda plates, the Sumatran subduction zone is featured by a strongly deformed slab coupling with the overlying plate, and complicated slab-mantle interactions, leading to frequent occurrence of great megathrust earthquakes (e.g., 2004 Mw9.2 and 2005 Mw8.7 events) and extremely intensive magmatism (e.g., Toba supervolcano). Previous seismic studies reveal a rugged slab surface with seamounts, and slab folding and tearing beneath Sumatra, both of which govern the features of earthquake rupture and magma generation associated with fluid release and mantle wedge hydration. However, the details of the slab geometry (e.g., along-strike variation of dip direction and dip angle) and the “slab dehydration-mantle hydration” process across the subducting plate boundary remain poorly known, due to limited data coverage and resolution of these studies.

To better reveal the geometry of the slab and the feature of “slab dehydration-mantle hydration” during the oblique subduction, in this study, we develop a Dip Direction Searching (DDS) method to constrain the dipping structure of slab and the nature of the slab upper boundary. In this method, we estimate dip directions of velocity discontinuities by grid search based on the back azimuthal variation of radial receiver functions (RFs). DDS is a single-station-based method thus applicable in the areas with sparse seismic instruments. Synthetic tests demonstrate that the DDS method has higher resolution (with uncertainty of several degrees) in dip direction estimation than traditional RF analysis approaches and is applicable to the cases with strong white noise contamination, incomplete/uneven back azimuthal coverage, <5%-10% crustal and mantle anisotropy, and their compound effects. The method also provides constraints on the thickness and depths of dipping layers.

Applying the DDS method, we find a dipping Low Velocity Layer (LVL) commonly beneath the forearc areas and constrain its depths, thickness, and dip directions. The depth and dip direction estimates are highly consistent with the Slab2 model, indicating that the LVL is at the subducting plate boundary. We interpret the lower boundary of the LVL as the subducting oceanic Moho, which is less deformed so its dip direction can represent the dip direction of the whole slab. The slab dip direction gradually increases from 47±5.3˚ in southern Sumatra to 70±10.7˚ in northern Sumatra, indicating an along-strike bending of slab, which is possibly related to the oblique subduction. We find that the dip directions at the upper and lower boundaries of the LVL differ up to 23˚ beneath central Sumatra, indicating the two boundaries are locally unparallel. The thickness of the LVL is estimated to be 10-14 km, larger than those of regular oceanic crusts (~7 km). These observations imply that the LVL is composed by not only the oceanic crust but also a low-velocity serpentinized mantle layer at the top. Therefore, the upper boundary of the LVL represents the serpentinization front, indicating a diffuse plate boundary.

How to cite: Feng, M., Chen, L., Wei, S., Wang, X., Wang, X., and Wu, Z.: Slab geometry and a diffuse plate boundary beneath Sumatra: constrained using a new receiver function analysis method, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5946, https://doi.org/10.5194/egusphere-egu23-5946, 2023.

Abstract:

The development of faults governs the kinematics of continental deformation. The Songliao Basin, located at the central part of late Mesozoic lithospheric thinning province in East Asian region, experienced intense rifting during Early Cretaceous epoch and formed an intricate syn-rift fault system. However, the geometric and kinematic relationships inherent in the fault system have not yet been satisfactorily explained, hampering the understanding of basin formation and related marginal plate tectonic processes. Here, theories for polymodal faulting were applied to evaluate the faulting evolution of the Songliao Basin, based on which a quantitively deformation reconstruction was developed. Our reconstruction shows that the basin formation during the syn-rifting period was subdivided into three main stages: late Valanginian–Barremian(133-118.2Ma) initiation of extension, Aptian(118.2-113.9M) extension climax, and Albian(113.9-100.5Ma) extension wanning and initiation of post-extensional subsidence. The deformation of the Songliao Basin is spatially heterogeneous. Faulting analyses revealed a three-dimensional strain filed with a dominating horizontal ESE-WNW extension, a minor horizontal near N-S extension, and a large vertical shortening in the Northern Songliao Basin (NSL). The 3-D non-plane strain with non-zero intermediated extension(ε2) magnitude controlled the synchronous displacement of a NNE–SSW-striking fault set and a NNW–SSE-striking fault set in orthorhombic pattern to create the characteristic rhomboidal fault geometry. Whereas, the Southern Songliao Basin (SSL) deformed under a 2-D plane strain filed with a horizontal ESE-WNW extension and vertical shortening. The plane strain condition is interpreted as a special case with no intermediated strain(ε2), and produces a pair of near N-S-striking fault sets in conjugate symmetry. Our results illustrate that this particular three-dimensional deformation result in the intricate fault system in the Songliao Basin and that the fault geometry is controlled by the ratios of the principal strains, especially the relative magnitude of the intermediate strain. We argue that the three-dimensional strain field in the NSL reflected the trench retreat in the Paleo-Pacific subduction zone and the gravitational collapse of the thickened lithosphere, and that the extension of the SSL is merely the consequence of the trench retreat.

Keywords:

Songliao Basin, three-dimensional strain, orthorhombic fault, syn-rift deformation, quantitative reconstruction

How to cite: xing, H.: Late Mesozoic rift evolution and deformation reconstruction of the Songliao Basin, northeastern China, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6117, https://doi.org/10.5194/egusphere-egu23-6117, 2023.

The stratigraphy of the southern half of Afghanistan has been studied and the timing of first order events have been established in some detail. By contrast, the structural evolution has not been treated with the same discernment. We here report the existence of a marginal fold and thrust belt within the Logar Syncline (western Afghanistan) that was detached along a décollement surface at the base of the Cambrian, mainly between Zargaran dolomites and polymictic conglomerates filling the underlying depressions. The basement consists of Pan-African magmatic and metamorphic rocks including volcanic tuffs making up the Loy Khwar Series. Some of this material has been worked into the conglomerates of the Loy Khwar. The overlying sedimentary package reaches from the Cambrian to the Permian and has been deformed into concentric folds. Nowhere do these folds expose the underlying Pan-African basement which crops out in the extreme SW, in a kind of root zone wherein the décollement separating the sedimentary package from the basement seems to root. Having a décollement within dolomites seems unexpected due to their presumed strength but a similar case has been reported from the Keystone Thrust of the Sevier Belt in Nevada. This phenomenon seems to be more widespread than previously thought.

How to cite: Lom, N. and Şengör, A. M. C.: The discovery of a Palaeozoic décollement in SW Afghanistan: orogenic events along the Tethyan edge of Gondwana-Land, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6614, https://doi.org/10.5194/egusphere-egu23-6614, 2023.

EGU23-7091 | ECS | Orals | GD9.1

Cenozoic Southwestern Tian Shan: Timing of Mountain Building, Intra-montane Basin Inversion, and Relation to Lithospheric Mantle Indentation 

Florian Trilsch, Sanaa Reuter, Ratschbacher Lothar, Shadi Ansari Jafari, Raymond Jonckheere, Birk Härtel, Christoph Glotzbach, and Bastian Wauschkuhn

Cenozoic reactivation of the Paleozoic thick-skinned fold-thrust belt of the southwestern Tian Shan has—as the Afghan-Tajik Basin inversion—been interpreted to reflect Indian mantle-lithosphere indentation underneath the Pamir. New low-temperature thermochronologic data, i.e. apatite fission-track (AFT), apatite (AHe), and zircon (ZHe) (U-Th)/He ages, reveal the exhumation history of the SW-Tajik Tian Shan along two N-S-transects. We date the reactivation and explore its temporal and spatial variations. Three domains emerged. In the Central Domain (Zeravshan-Gissar and Vashan), AFT data—aided by Raman-spectroscopic chemical-composition discrimination of detrital apatite samples and vitrinite-reflectance temperature estimates—record a ~10-13 Ma onset of shortening and >4 km exhumation. The Northern Domain, where the N-Zeravshan Fault constitutes a major Cenozoic structural divide reactivating the Paleozoic Zirabulak Suture, exhumed from <4 km, but apatite AHe ages outline a similar reactivation history as in the Central Domain. The synchronous structural reactivation implies rapid shortening propagation from the Pamir indenter across the Afghan-Tajik fold-thrust belt into and across the Tian Shan. In the Southern Domain (Gissar Batholith), ~7‒9 Ma AFT and ~4 Ma AHe ages suggest a southward shortening propagation from the northern Domains and anew thrust generation. In the hanging wall of major thrusts, ~3‒7 Ma-old AFT ages record significant and persistent exhumation but ZHe data limit it to <6 km. Most of the Southern and Central Domains cooled monotonously but temperature-time models indicate northward-decreasing reheating by syn-orogenic deposition, consistent with stratigraphic data.

How to cite: Trilsch, F., Reuter, S., Lothar, R., Ansari Jafari, S., Jonckheere, R., Härtel, B., Glotzbach, C., and Wauschkuhn, B.: Cenozoic Southwestern Tian Shan: Timing of Mountain Building, Intra-montane Basin Inversion, and Relation to Lithospheric Mantle Indentation, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7091, https://doi.org/10.5194/egusphere-egu23-7091, 2023.

EGU23-7378 | ECS | Posters on site | GD9.1

Towards understanding the crustal response of slab tearing and detachment: inferences from the Dinarides-Hellenides transition 

Nikola Randjelovic, Liviu Matenco, Maja Maleš, Nemanja Krstekanic, Uros Stojadinovic, Branislav Trivić, and Marinko Toljić

Convergence zones are often characterized by numerous subduction- to collision-related dynamics in many orogenic areas worldwide. Processes such as continental indentation, extrusion and slab roll-back can occur simultaneously along orogens as a consequence of different rates of convergence. Such along-strike variability accross the orogen can lead to migration of deformation from partly detached slab to the still active oceanic or continental subduction. These conditions create slab tearing often followed by rotation, rapid roll-back of the attached slab and/or exhumation of previously buried crust in the upper plate above the already detached slab. The main mechanism that explains transition from slabs with contrasting kinematics to the crustal level strain partitioning is still not fully understood.

One very good example of strain partitioning associated with indentation, slab-detachment and slab-tearing is the junction between the Dinarides and Hellenides in southeastern Europe. Following the Jurassic – Eocene closure of the Neotethys Ocean and subsequent Adria – Europe collision, the Dinarides - Hellenides orogen has recorded a significant extensional deformation. This extension was driven by the Oligocene – early Miocene slab detachment of the Dinarides slab, while the Hellenides segment continued its evolution until the present day.

We have performed a field kinematic and structural study in the less understood area of Montenegro near Dinarides - Hellenides transition to determine the influence of Oligocene – early Miocene deformation on Dinarides composite nappes. The results imply that Oligocene – early Miocene slab detachment followed by slab tearing was accommodated in crustal domain by bi-directional extension associated with the exhumation of mid-crustal levels in the footwall of both orogen-parallel and orogen-perpendicular faults, reactivation of inherited Cretaceous-Paleogene nappe contacts and formation of extensional klippen.

How to cite: Randjelovic, N., Matenco, L., Maleš, M., Krstekanic, N., Stojadinovic, U., Trivić, B., and Toljić, M.: Towards understanding the crustal response of slab tearing and detachment: inferences from the Dinarides-Hellenides transition, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7378, https://doi.org/10.5194/egusphere-egu23-7378, 2023.

EGU23-7625 | Orals | GD9.1

Sinking-slab triggered formation of the giant Ordos basin in central China 

Neng Wan, Shaofeng Liu, and Zhang Bo

The giant Late Triassic Ordos basin, developed along northern Tethyan margin where prolonged terrane amalgamation and accretion occurred, is characterized by rapid subsidence rate along its southwestern margin, but slow and uniform subsidence rate within its interior. Its formation mechanism still remains poorly understood. Here, we use flexural simulation and 4D-geodynamic modeling to explore the potential role of basin adjacent mountain belts and deep mantle processes towards basin subsidence, respectively. Flexural backstripping of stratigraphic record spanning from 245-201 Ma, along two SW-NE trending well sections perpendicular to the southwestern margin of Ordos basin clearly demonstrates that there were long wavelength anomalous subsidence components, here termed residual subsidence, in addition to those induced by thrust loads and sediment loads. From 245-201 Ma, residual subsidence increases from 0 m to ca. 500 m and gradually decreases from southwest towards northeast. Our results indicate that basin adjacent thrust loads could act as the dominant driver for subsidence of foredeep but have limited control towards basin interior. Other mechanism is required to explain the basin-wide anomalous residual subsidence. Long-wavelength nature of residual subsidence and its general agreement, regarding both the magnitude and trend, with dynamic topography predicted by an independently designed geodynamic model suggest that the anomalous subsidence component might be of dynamic origin. We attribute this excess residual subsidence as dynamic subsidence induced by the sinking slab beneath North China plate during and after the oblique closure of Mianlue ocean between North China plate and South China plate. We argue that the Ordos basin is triggered by subduction related mantle processes while modulated by flexural loading along its margin. Our findings may also shed light on formation mechanisms of other giant basins with similar settings in East Asia.

How to cite: Wan, N., Liu, S., and Bo, Z.: Sinking-slab triggered formation of the giant Ordos basin in central China, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7625, https://doi.org/10.5194/egusphere-egu23-7625, 2023.

Since Late Palaeozoic, the North China Block (NCB) experienced a unique tectonic process in which sequential plate subduction and collision took place around this once stable and rigid craton. Due to this multi-direction convergent setting and its small size, the NCB was characterized with intensive intracontinental deformation and associated depositional processes and magmatism during Mesozoic. However, conflicting debates on the timing and kinematics of the intracontinental deformations are still open to the geologist community and hamper the understanding of the driving forces. Our works focus on the syn-tectonic depositions, including syn-tectonic conglomerates and growth strata, in Mesozoic sedimentary basins in the Yanshan belt of northern NCB, and the high-precision zircon U-Pb geochronological data. Previously reported stratigraphic levels of regional unconformities and isotopic ages of igneous rocks in the Yanshan belt were also compiled in this study. Our results suggest that during Middle Triassic-earliest Jurassic (ca. 240-195 Ma), the northern NCB was dominated by nearly N-S compressional regime, leading to formation of large-scale E-W-trending thrust faults and basement-cored buckles. A significant magmatic lull was also witnessed within this period (ca. 210-195 Ma). This N-S crustal shortening was believed to be related with collision between the NCB and the Songliao-Nenjiang terrane along the Solonker suture. During Middle Jurassic-Early Cretaceous (ca. 172-135 Ma), the Yanshan belt underwent strong NW-SE contraction and gave rise to NE-SW-striking thrust faults, asymmetric folds, and reactivation of previous E-W thrust faults with prominent dextral component. Both deformation, deposition, and magmatism showed a westward younging trend in the Yanshan belt during Early Jurassic-Early Cretaceous (ca. 180-140 Ma), indicating their westward migration. However, magmatism turned to migrate toward east after that. All these lines of evidences could be integrated in a tectonic model with westward flat-slab subduction of the Paleo-Pacific/Izanagi plate beneath the East Asian continent. Early Jurassic witnessed an imported and profound transition from closure of the paleo-Asian Ocean to the subduction of the Paleo-Pacific Ocean plate.

How to cite: Lin, C. and Liu, S.: Mesozoic intracontinental deformations of the northern North China Block in a multi-direction convergent setting, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7701, https://doi.org/10.5194/egusphere-egu23-7701, 2023.

EGU23-7851 | ECS | Orals | GD9.1

Devonian Andean-type orogeny in the southern Dunhuang block (NW China): Petro-structural, geochronological and metamorphic P−T constraints 

Jérémie Soldner, Yingde Jiang, Pavla Štípská, Karel Schulmann, Chao Yuan, Zongying Huang, and Robert Anczkiewicz

The Dunhuang block in NW China preserves Archean to Paleoproterozoic basement rocks that are exposed alongside Paleozoic magmatic and metamorphic rocks. Although both subduction-accretion and collisional processes have been proposed for the formation of Paleozoic metamorphic rocks, links between their metamorphic ages, P−T evolution and deformational history remains ambiguous. Here we present zircon and in-situ monazite U−Pb geochronology linked to P−T modelling of metapelites from the Hongliuxia belt in the southern Dunhuang block. Oriented inclusion trails in garnet from metapelites reveal rare relics of an S1 fabric. The earliest continuous metamorphic fabric is an originally steep N-S striking foliation S2. This fabric was further reworked by upright folds F3 associated with development of an ubiquitous steep, mainly south-dipping, E-W striking axial planar foliation S3. The Bt−Ms−St−Pl−Qz−Tur−Ilm assemblage forming inclusions in garnet is assigned as the D1-M1a event whereas the foliation S1b in metapelites is associated with Grt–Ky–St–Bt–Ms–Pl–Qz–Rt assemblage. The Grt−Ky−St aligned parallel to the S2 matrix in low-strain domains are considered as remnants of a dismembered M1 assemblage, while the S2 foliation is characterized by the Grt–Sil–Bt–Pl–Qz–Rt–Liq in high-strain domains. The S3 foliation is associated with the Grt–Sil–Bt–Ms–Pl–Qz–Kfs–Chl–Ilm assemblage. Altogether, metapelites record similar clockwise P–T evolution an early prograde (M1a) stage starting at 4.5–5 kbar and 500–550°C, metamorphic peak (M1b) stage at ~8 kbar and 700–725°C, decompressional heating to ~6 kbar and ~750°C (M2) and a retrograde stage to 4.5–5.5 kbar and 500–550°C (M3). Zircon U−Pb geochronological investigations suggest that metapelites from the basement record metamorphic ages of 1847 ± 11 Ma and 404 ± 15 Ma.  In-situ U–Pb dating of monazite combined to monazite trace-element composition analysis further suggest that the rock burial most likely started at c. 410 Ma, peak-P conditions M1b were reached at 400–395 Ma, M2 heating occurred at c. 390 Ma and M3 retrogression occurred between c. 384 and 353 Ma. The D1-M1 burial event reflects either underthrusting of the basement below the supra-subduction active margin system or propagation of the deformation front to the south of the Dunhuang block. The D2-M2 event is a consequence of thermal relaxation following crustal thickening, possibly accompanied by convective lithospheric thinning, whereas D3-M3 reflects exhumation during shortening of the system. Combined with the available regional data, it is suggested that the Devonian multi-stage tectono-metamorphic evolution described in the study area corresponds to a polyphase Andean-type deformation of the active margin of the Dunhuang block. Such a process can be regarded as a response to a progressive relocation of the Dunhuang block alongside with the Tarim-North China Collage in the Devonian.

 

Funding: This research is part of the project No. 2021/43/P/ST10/02996 co-funded by the National Science Centre and the European Union Framework Program for Research and Innovation Horizon 2020 under the Marie Skłodowska-Curie grant agreement No. 945339, as well as the President’s International Fellowship Initiative for Postdoctoral Researchers of the Chinese Academy of Sciences, grant No. 2021PC0013.

How to cite: Soldner, J., Jiang, Y., Štípská, P., Schulmann, K., Yuan, C., Huang, Z., and Anczkiewicz, R.: Devonian Andean-type orogeny in the southern Dunhuang block (NW China): Petro-structural, geochronological and metamorphic P−T constraints, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7851, https://doi.org/10.5194/egusphere-egu23-7851, 2023.

EGU23-8253 | ECS | Posters on site | GD9.1

Seismic imaging of the lithospheric structures in the Iranian Makran subduction zone 

Zimu Wu, Ling Chen, Haiqiang Lan, Morteza Talebian, Xu Wang, Yifan Gao, Jianyong Zhang, Yinshuang Ai, Mingming Jiang, and Yingjie Yang

The Makran subduction zone (MSZ) is located in between the Zagros mountain belt to the west and Himalayan orogen to the east, forming a transition from oceanic subduction to continental collision on both sides along the Tethyan orogenic belt. The Arabian oceanic plate, a narrow remnant of the Neotethys ocean, is subducting northward beneath the Eurasian plate in Makran. Such a unique tectonic setting makes the MSZ an ideal place to investigate the geodynamic processes in response to subduction-collision transition. Since most of the Neotethys has already dived into the deep mantle and the associated geological records are not always well preserved due to the strong collision, the MSZ also provides a special opportunity to explore the evolution history of the Neotethys in a more direct way.

To better understand the deep dynamics of the subduction-collision transition and evolution of the Neotethys, we investigated the lithospheric structure, especially the depth variation of the lithosphere-asthenosphere boundary (LAB), across the Iranian MSZ by S-wave receiver function (SRF) imaging. The teleseismic data used were acquired from 67 broadband stations that were operational from March 2017 to September 2018 in southeastern Iran. This temporary array constitutes the third phase of seismic observations under the “China-Iran Geological and Geophysical Survey in the Iranian Plateau” project.

Our SRF migration images show clear structural variations of both the upper and lower plates in the MSZ. In the upper plate in the southeastern Iranian plateau, we image a thin lithosphere (70-90 km) with monotonic decrease in LAB depth from the plateau interior to the arc region. This arc-ward thinning is probably caused by the focused thermal and chemical erosion at the LAB by arc magmatism. The LAB of the subducting slab is imaged at ~110-90 km depth near the coast but with an unexpected ~20-km deepening along the trench-parallel direction. Assuming a 25-km-thick accretionary wedge (deduced from active-source data), the observed ~85-65-km-thick slab is consistent with the thermal predictions for a mature oceanic lithosphere. However, the trench-parallel LAB step can hardly be explained by the age difference of the Neotethys but may be a result of the Cretaceous plate-mantle plume interaction. The plume-modified slab could be characterized by low density and high viscosity, and thus play an important role in forming low-angle (<10°) subduction beneath the present-day Makran fore-arc region. Our results also suggest that the thin overriding lithosphere is a persistent feature in both the MSZ and the neighboring continental collision/subduction zone, which favors the idea that the vertical-axis rotation and possible convective thinning dominate the evolution of central-east Iranian microblocks during the late Cenozoic. In addition, we detect an east-dipping structure at 70-90 km depth beneath the Zagros-Makran border, perhaps indicating a relatively sharp contact relationship between the oceanic and continental portions of the Arabian plate. These new observations imply a much more complex tectonic evolution than previously envisaged in the MSZ and adjacent subduction-collision transitional area, which deserves future studies to understand the continuous process from Neotethys subduction to continental collision.

 

How to cite: Wu, Z., Chen, L., Lan, H., Talebian, M., Wang, X., Gao, Y., Zhang, J., Ai, Y., Jiang, M., and Yang, Y.: Seismic imaging of the lithospheric structures in the Iranian Makran subduction zone, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8253, https://doi.org/10.5194/egusphere-egu23-8253, 2023.

EGU23-8755 | ECS | Posters virtual | GD9.1

Crustal Deformation of Biga Peninsula and Structural Controls on Porphyry Cu-Au and Epitermal Au Mineralization in Kirazlı Gold Deposit (Türkiye) 

Mehmet Çam, İlkay Kuşcu, Nuretdin Kaymakcı, and Mehtap Karcı

Kirazlı porphyry Cu-Au and epitermal Au mineralization is located in Biga peninsula where the region hosts numerious porphyry- and epithermal- style Au mineralizations within the Tethyan orogenic belt. Crustal deformation in the region is resulted by Cretaceous collusion during the closure of northern branch of Neotethys Ocean, related subduction, post-collusion, Cenozoic extension and following dextral strike-slip deformation regime which is emerged during the westward migration of Anatolian plate. The study includes regional fault mapping, slip data collection from regonal and district scale faults for paleostress analysis, oriented surface sampling of vein hosted deformational zones and micro-structural thin section examinations of oriented samples. Paleostress findings and fault orientations indicates two seperate character of deformations as nearly E-W trending extensional fault systems and subsequent NE-SW striking, steeply dipping dextral strike-slip faults with accompanying NNW-SSE trending left-lateral strike slip and ENE-WSW trending dextral strike-slip and oblique-slip faults. Later tectonic phase related with N-E Dextral strike-slip faults establishes the main deformational trend with accompanying district scale  R (synthetic) ENE-WSW trending dextral and NNW-SSE trending R' (antithetic) sinistral strike-slip faults. Slip data related to  E-W and ENE-WSW faults indicate that these faults are subjected to both N-S trending extensional and NE-SW trending dextral strike-slip tectonic regime. The petrographic and textural studies of oriented thin sections resulted in identification of two predominant vein directions as ENE-WSW and NNW-SSE of porphyry mineralization within the project area. ENE-WSW trending syntaxial, streched-blocky quartz bearing veins indicates multiple N-S extension and crack-seal events and postdated by NNW-SSE trending quartz veins. Also the veins with same orientation which were observed during field studies share similar orientations.

This study presents the early results off Ph.D. thesis "Crustal Extension and its Relationship to Porphyry Cu-Au and Epithermal Au Mineralization in the Kirazlı Gold Deposit (Çan, Çanakkale, Türkiye)" and supported by Alamos Gold Inc..

How to cite: Çam, M., Kuşcu, İ., Kaymakcı, N., and Karcı, M.: Crustal Deformation of Biga Peninsula and Structural Controls on Porphyry Cu-Au and Epitermal Au Mineralization in Kirazlı Gold Deposit (Türkiye), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8755, https://doi.org/10.5194/egusphere-egu23-8755, 2023.

EGU23-9971 | Orals | GD9.1 | Highlight

The Pacific basal mantle structure could be older than the African one 

Nicolas Flament, Omer Bodur, Simon Williams, Andrew Merdith, Dietmar Muller, John Cannon, Michael Tetley, Xianzhi Cao, and Sabin Zahirovic

Plate tectonics shapes Earth’s surface and is linked to motions within its deep interior. Cold oceanic lithosphere sinks into the mantle, and hot mantle plumes rise from the deep Earth, leading to volcanism. Volcanic eruptions over the past 320 million years have been linked to two large structures at the base of the mantle presently under Africa and the Pacific Ocean. This has led to the hypothesis that these basal mantle structures could have been stationary over geological time, in contrast to observations and models suggesting that tectonic plates, subduction zones, and mantle plumes have been mobile and that basal mantle structures are presently deforming. Here we reconstruct mantle flow from one billion years ago to the present day to show that the history of volcanism is statistically as consistent with mobile basal mantle structures as with fixed ones. In our reconstructions, cold lithosphere sank deep into the African hemisphere between 740 and 500 million years ago, and from 400 million years ago the structure beneath Africa progressively assembled, pushed by peri-Gondwana slabs, to become a coherent structure as recently as 60 million years ago. In contrast, the structure beneath the Pacific Ocean was established between 400 and 200 million years ago. These results confirm the link between basal mantle structures and surface volcanism, and they suggest that basal mantle structures are mobile, and aggregate and disperse over time, similarly to continents at Earth’s surface. This implies that the present-day shape and location of basal mantle structures may not be a suitable reference frame for the motion of tectonic plates.

How to cite: Flament, N., Bodur, O., Williams, S., Merdith, A., Muller, D., Cannon, J., Tetley, M., Cao, X., and Zahirovic, S.: The Pacific basal mantle structure could be older than the African one, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9971, https://doi.org/10.5194/egusphere-egu23-9971, 2023.

The plate tectonic history of the Pacific Ocean and its predecessor ocean, Panthalassa, are challenging regions on Earth to reconstruct during the Mesozoic-Cenozoic eras. More than 95% of Pacific-Panthalassa crust has been subducted into the Earth’s interior since the Jurassic, and this has created extensive (>9000 km length) plate reconstruction gaps between the Pacific and Eurasia/Laurasia. Here we build four contrasted NW Pacific-Panthalassa global plate reconstructions and assimilate their velocity fields into the global geodynamic models using the code TERRA: Andean-style subduction along East Asia following the corrected ‘R’ Matthews et al. (2016); and, three models that include intra-oceanic subduction within Pacific-Panthalassa with increasing tectonic complexity.   We compare our predicted present mantle structure, synthetic geoid and dynamic topography to Earth observations. P-wave tomographic filtering of predicted mantle structures allows for more explicit comparisons to global tomography.

All three plate reconstructions that include NW Pacific-Panthalassa intra-oceanic subduction fit better to the observed long-wavelength geoid and residual topography.  Correlations between modeled and imaged mantle structure do not systematically favor any single model, and this is attributed to limited tomographic resolution within the central Pacific mantle relative to variability in our modeled mantle structures.  Taken together, our results robustly show the likelihood of intra-oceanic subduction within NW Pacific-Panthalassa.  This presents a challenge to popular plate models of Andean-style subduction along East Asia, which are deeply-embedded into most published plate tectonic, geodynamic and geologic studies.  Our geodynamic models predict significant (>2000 km from Mesozoic to present) southeastwards lateral slab advections within the lower mantle that would confound ‘vertical slab sinking’-style restorations of ancient subduction zones.  Plate reconstructions that can better incorporate intra-oceanic subduction within Pacific-Panthalassa may improve our knowledge of past global CO2, mantle flow, and dynamic topography histories.

How to cite: Wu, J., Lin, Y.-A., and Colli, L.: NW Pacific-Panthalassa intra-oceanic subduction during Mesozoic-Cenozoic times from mantle convection and geoid models, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10007, https://doi.org/10.5194/egusphere-egu23-10007, 2023.

EGU23-10233 | ECS | Orals | GD9.1 | Highlight

Strong variability in the thermal structure of Tibetan Lithosphere 

Bing Xia, Irina Artemieva, Hans Thybo, and Simon Klemperer

We present a model of thermal lithospheric thickness (the depth where the geotherm reaches a temperature of 1300°C) and surface heat flow in Tibet and adjacent regions based on the new thermal-isostasy method. The method accounts for crustal density heterogeneity, is free from any assumption of a steady-state lithosphere thermal regime, and assumes that deviations from crustal Airy-type isostasy are caused by lithosphere thermal heterogeneity. We observe a highly variable lithospheric thermal structure which we interpret as representing longitudinal variations in the northern extent of the subducting Indian plate, southward subduction of the Asian plate beneath central Tibet, and possible preservation of fragmented Tethyan paleo-slabs. Cratonic-type cold and thick lithosphere (200-240 km) with a predicted surface heat flow of 40-50 mW/m2 typifies the Tarim Craton, the northwest Yangtze Craton, and most of the Lhasa Block that is likely refrigerated by underthrusting Indian lithosphere. We identify a ‘North Tibet anomaly’ with thin (<80 km) lithosphere and high surface heat flow (>80-100 mW/m2). We interpret this anomaly as the result of removal of lithospheric mantle and asthenospheric upwelling at the junction of the Indian and Asian slabs with opposite subduction polarities. Other parts of Tibet typically have intermediate lithosphere thickness of 120-160 km and a surface heat flow of 45-60 mW/m2, with patchy anomalies in eastern Tibet. While different uplift mechanisms for Tibet predict different lithospheric thermal regimes, our results in terms of a highly variable thermal structure beneath Tibet suggest that topographic uplift is caused by an interplay of several mechanisms.

How to cite: Xia, B., Artemieva, I., Thybo, H., and Klemperer, S.: Strong variability in the thermal structure of Tibetan Lithosphere, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10233, https://doi.org/10.5194/egusphere-egu23-10233, 2023.

A range of interpretations of regional geology have led to diverging models describing the elusive predecessor marginal basin to the South China Sea, with significant implications for interpreting regional extrusion tectonics and volcanic episodes. Interpretations contrast between the presence or absence of the Proto South China Sea, while models arguing for a Proto South China Sea also diverge in the geodynamic origin of the marginal sea as either 1) a trapped piece of Cretaceous-age proto Pacific (namely, Izanagi) crust, or 2) sourced from back-arc opening along the east Asian margin.

I will provide a comparison of proposed models for the Proto South China Sea, and I will argue that the existence of a Proto South China Sea, including in the region north of Borneo, is a necessity for reconciling multiple and independent geological and geophysical constraints. First, a back-arc basin along east Asia in the Late Cretaceous helps explain tectonic subsidence curves, the presence of Late Cretaceous ophiolites on Mindoro, and also the abandonment of Andean-style arc volcanism on the South China continental margin. Second, regional basin histories and even the tectonic structure of Luzon Island and northwest Borneo suggest continental or arc fragments from east Asia were accreted in both settings. And finally, the ~50 to 20 Ma subduction-related volcanic history on Borneo, the presence of mapped sutures, evidence of subducted slabs in seismic tomography, requires significant south-dipping subduction of a Proto South China Sea. However, interpretations of a number of features, including the Billiton Depression, the Bentong-Raub Suture, and the West Baram Line on Borneo, and the origin of the Natuna Islands granites continue to provoke continued divergence in models for the region.

I will present an updated plate tectonic reconstruction in GPlates that incorporates recent spatial and temporal constraints, such as the west-east division of Luzon island (South China and Pacific affinity, respectively), and the timing of Proto South China Sea back-arc opening, closure, and accretion events. To test the new model, I show that the model conforms to plate kinematic constraints (such as reasonable convergence rates, and associated arc volcanism). In addition, I present new forward models of mantle flow in CitcomS, and compare the predictions to high-resolution P-wave tomography models (e.g. MIT-P08, UU-P07).

Although more geochronological and geochemical constraints are needed to establish the nature and age of the sutures on northwest Borneo, a clearer tectonic model for this area is essential in guiding mineral exploration – as established models have proposed there has been no subduction in this region since ~100 Ma. The new model presented here argues that subduction ceased much more recently, likely by ~20-15 Ma, coinciding with the arrival of the Dangerous Grounds block in the northern Borneo Trough, choking subduction, triggering the Sabah Orogeny, the eruption of Sintang-area adakites (related to slab break-off), and the abandonment of seafloor spreading in the South China Sea at ~15 Ma. Reconciling these interpretations will improve our understanding of paleogeography, basin evolution, sedimentary provenance, and regional geodynamics.

How to cite: Zahirovic, S.: The geological, tectonic, and geodynamic fingerprint of the elusive Proto South China Sea back-arc basin in northern Borneo, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10720, https://doi.org/10.5194/egusphere-egu23-10720, 2023.

EGU23-10968 | ECS | Orals | GD9.1

Sedimentary Basins of Kazakhstan and Occurrence of Copper and Uranium: A Geological Overview and Tectonic Analysis 

Azam Soltani Dehnavi, Reimar Seltmann, and Fereshteh Shabani

 

Several sedimentary basins (out of 15 basins) in Kazakhstan are characterized by the association of sandstone-type uranium and sedimentary-hosted copper mineralization with oil, gas or coal fields. In central Kazakhstan, the Chu-Sarysu basin (along with Syr-Darya basin), both hosting a multicolored clay–gravel–sandstone sequence, are famous for roll-front type uranium deposits. The Chu-Sarysu basin is also the host of the world-class historical giant deposit of Dzhezkazgan (22 million metric tons) sandstone-hosted copper (by-product of rhenium) as well as smaller deposits of Zhaman-Aibat and the Zhilandy group. The Teniz depression, located in the northern Chu-Sarysu basin, is also prospective for the occurrence of sedimentary copper. Both basins share lithological and structural peculiarities significant to mineralization. The Teniz and Chu-Sarysu basins originated during the development of the Altaid Orogen (Wilhelm, et al., 2012). The Chu-Sarysu and Teniz basins are characterized by a continental-marine-continental depositional cycle from Devonian to Permian. The base of basins includes Early to Middle Devonian intermediate volcanic and volcanoclastic rocks grading upward into Late Devonian red beds (Box et al., 2012; Cossette et al., 2014). The Early Carboniferous is marked by the deposition of lagoonal to marginal-marine salt-bearing strata, which is overlain by Late Carboniferous to Permian alluvial-lacustrine red beds, and a shale-limestone sequence. Both Chu-Sarysu and Teniz basins endured the folding of rocks in the Permian, generating dome-and-basin forms. Both basins are marked by parallel strike-slip lineaments likely related to Permian Kazakhstan oroclinal bending, resulting in a back-arc/rift-graben development. The localization of most of the Cu deposits at the Chu-Sarysu basin is adjacent to the intersection of F2 anticlines (N-NW-trending) with the syn-depositional folding F1 anticlines (E-NE-trending) within the zones of sandstone bleaching. The F1 anticlines locally trapped petroleum fluid deposits. These structures are the pathway of the flow of dense ore brines across the petroleum-bearing anticlines, resulting in ore sulfide deposition via two fluids mixed. Satellite images display the same structural pattern in the Teniz basin, which can assist to narrow down the prospecting regions for copper occurrences. Since the sedimentary-hosted copper systems are complicated in terms of the mineralization events, the comparison of the two basins enables to generate valuable information related to depositional patterns and to guide exploration. Also, non-genetic special relationship between uranium and copper can be postulated.

 

References

Box, S. E., Syusyura, B., Seltmann, R., Creaser, R. A., Dolgopolova, A., & Zientek, M. L., 2012, Dzhezkazgan and associated sandstone copper deposits of the Chu-Sarysu Basin, Central Kazakhstan. Econ. Geol. Sp. Publ, 16, p. 303-328.

 

Cossette, P.M., Bookstrom, A.A., Hayes, T.S., Robinson, G.R., Jr., Wallis, J.C., and Zientek, M.L., 2014, Sandstone copper assessment of the Teniz Basin, Kazakhstan: U.S. Geological Survey Scientific Investigations Report 2010–5090–R, 42 p.

 

Wilhem, Caroline, Windley, B.F., and Stampfli, G.M., 2012, The Altaids of Central Asia—A tectonic and evolutionary innovative review: Earth-Science Reviews, v. 113, p. 303– 341.

How to cite: Soltani Dehnavi, A., Seltmann, R., and Shabani, F.: Sedimentary Basins of Kazakhstan and Occurrence of Copper and Uranium: A Geological Overview and Tectonic Analysis, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10968, https://doi.org/10.5194/egusphere-egu23-10968, 2023.

EGU23-11327 | ECS | Orals | GD9.1

Paleoelevation Reconstruction of Subduction Zones in Eastern Pacific Continental Margins Quantitatively with Igneous Geochemistry 

Bingxi Liu, Simon Williams, Guochun Zhao, Shan Yu, and Dongchuan Jian

Reconstructing past episodes of mountain building from the geological rock record is one of the main challenges for unravelling the ancient physical geography of Earth’s surface. Mountains and mountain ranges, often situated at convergent plate margins, play a pivotal role in many fields of the Earth, climate, and biological sciences. Established methods for quantifying past elevations traditionally relied on sedimentary rocks, but in recent years, alternative approaches have emerged on the basis that geochemical signatures of magmatic rocks formed in convergent settings correlate with crustal thickness or elevation. These correlations allow for empirical relations of igneous whole-rock ratios such as La/Yb and Sr/Y with Moho depth for modern convergent settings, which can then be used to estimate ancient crustal thickness or paleoelevation. Since a relatively large number of igneous samples are available for pre-Cenozoic times compared to other paleoelevation proxies, these methods have the potential to allow quantitative mapping of past topographic change for times where existing maps are largely based on a qualitative approach.

Here, we investigate the application of paleoelevation estimates derived from geochemistry using the Pacific margin of South America as a case study. We investigate their consistency with independent indicators of past elevations such as stratigraphy, stable isotopes, fossils etc. for Cenozoic samples along the Andean margin. For older times, we compare the estimated paleoelevations with other aspects of the geological record, as well as equivalent values from global paleogeography models widely used in climate modelling studies, to evaluate the extent to which these models are consistent with the igneous geochemical proxies. We derive paleoelevation estimates according to different data filtering schemes, showing that a major consequence of the choice of geochemistry filter is the number of data points left after the filtering. We find that the igneous geochemical proxies yield elevations broadly consistent with traditional results for the Cenozoic, though our results do not resolve some of the rapid uplifts recorded by other proxies. In deeper time, we show that igneous geochemistry quantifies changes in elevation related to documented phases of crustal thickening and thinning, and is thus likely to allow improvements to existing maps of paleotopography. 

How to cite: Liu, B., Williams, S., Zhao, G., Yu, S., and Jian, D.: Paleoelevation Reconstruction of Subduction Zones in Eastern Pacific Continental Margins Quantitatively with Igneous Geochemistry, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11327, https://doi.org/10.5194/egusphere-egu23-11327, 2023.

EGU23-12290 | Orals | GD9.1

Lithium pegmatites of the Kalba-Narym Belt, East Kazakhstan: Geological overview 

Gleb Smirnov, Reimar Seltmann, and Azam Soltani Dehnavi

The Kalba-Narym Belt is part of the Central Asian Orogenic Belt (CAOB) and formed due to the
continental collision between Kazakhstan and Siberian plates in the Late Paleozoic. Several
plutons comprising the Kalba-Narym granitic batholith are considered post-orogenic. The
commonly accepted theory claims that these intrusive bodies might have been formed due to
the far-spreading influence of the Tarim mantle plume (Khromykh et al., 2019). However, the
volcanic facies, that are normally associated with plume-related activities are present only
sporadically in the Kalba-Narym area, which may imply that the heat source is plume-unrelated
and instead linked to mafic underplating and uplift processes of the crust. Amongst the variable
intrusive rocks formed in this region, highly-fractionated pegmatites are particularly important
but nevertheless remain poorly understood with origin controversially discussed. The
mineralized pegmatites are associated with Phase 1 granites of the Kalba complex, with a
40Ar/ 39Ar age of 297 to 290 Ma (Kotler et al., 2021). The formation of pegmatites, driven either
by the differentiation of granitic melts or by anatectic melting processes, was likely
supplemented by the inputs of volatiles and rare metals with fluids. The rocks of the best-
known pegmatite occurrences located near Asubulak village, such as Yubileynoye and Krasny
Kordon deposits, can be categorized as LCT pegmatites, including three main zones based on
mineralogical and geochemical assemblages of a) microcline-albite with pollucite and petalite
(Ta, Cs, Be, Sn), b) microcline-albite with spodumene (Ta, Nb, Cs, Li, Be, Sn), and c) spodumene-
albite (Li, Ta, Nb, Sn) (D'yachkov et al., 2021).
Apart from the mineralized pegmatites, there are known occurrences of barren pegmatites,
which creates an opportunity for comparison with the mineralized pegmatites specifically via
contrasting geochemical signatures. Aiming at a proper understanding of the pegmatite
genesis, mineralization mechanisms and geochemical approach on a bigger regional scale of the
Greater Altai may open up unique perspectives for the future exploration of the region.
Therefore, this presentation provides an overview and re-evaluation of the detailed geological
characteristics of the Kalba-Narym Belt, continuous into Chinese Altai, and the processes
involved in rare-metal pegmatite mineralization.

References:
D'yachkov, B. A., Bissatova, A. Y., Mizernaya, M. A., Zimanovskaya, N. A., Oitseva, T. A.,
Amralinova, B. B., Aitbayeva, S. S., Kuzmina, O. N., &amp; Orazbekova, G. B. (2021). Specific
Features of Geotectonic Development and Ore Potential in Southern Altai (Eastern
Kazakhstan). Geology of Ore Deposits, 63(5), 383–408.
https://doi.org/10.1134/s1075701521050020


Khromykh, S. V., Oitseva, T. A., Kotler, P. D., D’yachkov, B. A., Smirnov, S. Z., Travin, A. V.,
Vladimirov, A. G., Sokolova, E. N., Kuzmina, O. N., Mizernaya, M. A., &amp; Agaliyeva, B. B.
(2020). Rare-metal Pegmatite Deposits of the Kalba Region, Eastern Kazakhstan: Age,
Composition and Petrogenetic Implications. Minerals, 10(11), 1017.
https://doi.org/10.3390/min10111017

Kotler, P., Khromykh, S., Kruk, N., Sun, M., Li, P., Khubanov, V., Semenova, D., &amp; Vladimirov, A.
(2021). Granitoids of the Kalba Batholith, Eastern Kazakhstan: U–PB Zircon Age,
Petrogenesis and Tectonic Implications. Lithos, 388-389, 106056.
https://doi.org/10.1016/j.lithos.2021.106056

How to cite: Smirnov, G., Seltmann, R., and Soltani Dehnavi, A.: Lithium pegmatites of the Kalba-Narym Belt, East Kazakhstan: Geological overview, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12290, https://doi.org/10.5194/egusphere-egu23-12290, 2023.

EGU23-12729 | ECS | Orals | GD9.1

Detection and (re)location of earthquakes using Jammu And Kashmir Seismological NETwork 

Sk Shamim, Ayon Ghosh, Supriyo Mitra, Keith Priestley, and Sunil Kumar Wanchoo

Broadband waveform data from the recently established Jammu And Kashmir Seismological NETwork (JAKSNET) has been used to detect and locate earthquakes in the Jammu and Kashmir (J&K) Himalaya. Continuous data recorded by the network between 2015 and 2018 has been used for the analysis. The Coalescence Microseismic Mapping (CMM) algorithm is used to detect and locate hundreds of earthquakes, not reported in regional and global catalogs. These earthquakes are then relocated using a probabilistic relocation method of NonLinLoc (NLL). This produced a subset of earthquakes within 200 km of the network and having spatial uncertainty of less than 10 km. Most of the earthquakes are located beneath the Lesser and Higher Himalaya, with depth less than 25 km. A few earthquakes have depths between 30-60 km and lie across the entire region. The shallow earthquakes occur within the Himalayan wedge and define the locked-to-creep transition (unlocking) zone on the Main Himalayan Thrust. These earthquakes occur in clusters in the Jammu-Kishtwar segment, immediately south of the Kishtwar window, beneath the Kashmir Valley and in the NW Syntaxis, surrounding the 2005 (Mw 7.6) Kashmir earthquake source zone. These events provide the first evidence of the MHT locked segment beneath J&K Himalaya. The deeper events are within the underthrusting Indian crust, which reveal that the entire Indian crust is seismogenic. Double-difference algorithm is being used to improve the relative location of the shallow events to study possible clustering of earthquakes in the MHT.  

How to cite: Shamim, S., Ghosh, A., Mitra, S., Priestley, K., and Wanchoo, S. K.: Detection and (re)location of earthquakes using Jammu And Kashmir Seismological NETwork, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12729, https://doi.org/10.5194/egusphere-egu23-12729, 2023.

EGU23-13519 | ECS | Posters on site | GD9.1

Effects of strain- vs. strain-rate-dependent faults weakening for continental corner collision: insight from 3D thermomechanical models 

Luuk van Agtmaal, Attila Balazs, Dave May, and Taras Gerya

Geological and geophysical observations have highlighted the multi-stage deformation history of the continental lithosphere. Such inherited heterogeneities, observed from microscopic to kilometre-scales, lead to important mechanical weakening for the subsequent development of orogens. This strain-weakening may be frictional (fault gauge, filled veins), ductile (banding, recrystallisation, etc) or caused by changes in grain-size, and largely determines the response of the lithosphere to stresses (Bercovici & Ricard, 2014). Representing the microstructural weakening mechanisms with the relatively low resolution of regional and global numerical modelling studies has been a longstanding challenge. Mechanisms are often grouped into an “effective” plastic strain weakening implementation, where the frictional strength decreases with increasing accumulated strain. Alternatively, materials can be modelled to weaken depending on the local strain-rate (Ruh et al., 2014), which is characteristic for e.g. coseismic frictional weakening of faults. Here we show key differences of strain- vs. strain-rate-dependent faults weakening in terms of orogenic strain propagation patterns in numerical models of a corner collision setting, based on the eastern corner of the India-Eurasia collision. The numerical model I3ELVIS (Gerya & Yuen, 2007) consists of a finite-difference, marker-in-cell method coupled to a diffusion-advection-based finite-difference surface process model, FDSPM (Munch et al., 2022). We highlight key differences between the results of a model with strain-rate-dependent weakening, and a model with conventional strain-dependent weakening based on accumulated strain. The former shows significantly sharper shear zones, as well as a higher number of thrust faults that are relatively evenly spaced, which is more realistic in natural collision zones. 

 

Gerya, T. V., & Yuen, D. A. (2007). Robust characteristics method for modelling multiphase visco-elasto-plastic thermo-mechanical problems. Physics of the Earth and Planetary Interiors, 163(1), 83–105. https://doi.org/10.1016/j.pepi.2007.04.015

Bercovici, D., & Ricard, Y. (2014). Plate tectonics, damage and inheritance. Nature, 508(7497), 513–516. https://doi.org/10.1038/nature13072

Ruh, J. B., Gerya, T., & Burg, J.-P. (2014). 3D effects of strain vs. Velocity weakening on deformation patterns in accretionary wedges. Tectonophysics, 615–616, 122–141. https://doi.org/10.1016/j.tecto.2014.01.003

Munch, J., Ueda, K., Schnydrig, S., May, D. A., & Gerya, T. V. (2022). Contrasting influence of sediments vs surface processes on retreating subduction zones dynamics. Tectonophysics, 836, 229410. https://doi.org/10.1016/j.tecto.2022.229410

 

How to cite: van Agtmaal, L., Balazs, A., May, D., and Gerya, T.: Effects of strain- vs. strain-rate-dependent faults weakening for continental corner collision: insight from 3D thermomechanical models, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13519, https://doi.org/10.5194/egusphere-egu23-13519, 2023.

EGU23-13642 | ECS | Orals | GD9.1 | Highlight

The Dynamics of the India-Eurasia Collision: A Suite of Faulted Viscous Continuum Models Constrained by New High-Resolution Sentinel-1 InSAR and GNSS Velocities 

Jin Fang, Greg Houseman, Tim Wright, Lynn Evans, Tim Craig, John Elliott, and Andy Hooper

Block versus continuum description of lithospheric deformation in the India-Eurasia collision zone has been hotly debated over many decades. Here we apply the adapted two-dimensional (2-D) Thin Viscous Shell (TVS) approach explicitly accounting for displacement on major faults in Tibet (Altyn Tagh, Haiyuan, Kunlun, Xianshuihe, Sagaing, and Main Pamir Thrust Faults) and investigate the impact of lateral variations in depth-averaged lithospheric strength. We present a suite of dynamic models to explain the key observations from new high-resolution Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) as well as Global Navigation Satellite System (GNSS) velocities. Comparisons between calculated and observed velocity and strain rate fields indicate: (a) internal buoyancy forces from Gravitational Potential Energy (GPE) acting on a relatively weak region of high topography (~2,000 m) contribute to dilatation of high plateau and contraction on the margins; (b) a weak central Tibet (~1021 Pa s relative to far-field depth-averaged effective viscosity of 1022 to 1023 Pa s) yields the observed long-wavelength eastward velocity variation away from major faults; (c) slip resistance on faults produces strain localization and clockwise rotation around the Eastern Himalayan Syntaxis (EHS). We discuss the tectonic implications for rheology of the lithosphere, distribution of geodetic strain, and partitioning of active faulting and seismicity in light of our best-fit geodynamic solutions.

How to cite: Fang, J., Houseman, G., Wright, T., Evans, L., Craig, T., Elliott, J., and Hooper, A.: The Dynamics of the India-Eurasia Collision: A Suite of Faulted Viscous Continuum Models Constrained by New High-Resolution Sentinel-1 InSAR and GNSS Velocities, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13642, https://doi.org/10.5194/egusphere-egu23-13642, 2023.

EGU23-14244 | ECS | Posters virtual | GD9.1

The birth of the Mesotethys ocean recorded in the Southern Pamir Triassic basalts  

Jovid Aminov, Denis Mikhailenko, Sharifjon Odinaev, Mohssen Moazzen, Guillaume Dupont-Nivet, Yunus Mamadjanov, Aleksandr Stepanov, Jovid Yogibekov, and Sohibnazar Ashuraliev

The Pamir orogen, the western extension of the Tibetan plateau, formed and uplifted due to Mesozoic terrane amalgamation and Cenozoic India-Asia collision. The Mesozoic history of the amalgamation of Gondwana-derived Cimmerian terranes to the southern margin of Eurasia that produced the crust of the Pamirs is poorly understood. The birth and demise of an oceanic basin that divided Central and Southern Pamir in the early Mesozoic is an example of a gap in the knowledge of Pamir orogen formation throughout the Mesozoic and Cenozoic eras. Termed Mesotethys, this ocean likely originated in the early Permian when the Cimmerian super-terrane broke from Gondwana's northern limit. Geochemistry of early Permian basalts suggests this rifting event was driven by a plume that generated a seamount or series of seamounts that accreted to the Central Pamir before the Mesotethys closed in the late Triassic. Vestiges of the Mesotethys are preserved in the Rushan - Pshart suture zone.   This zone comprises Permian and Triassic marine sedimentary strata and thick layers of volcanic rocks, including the late Triassic basalts. This volcano-sedimentary sequence is intruded by the late Triassic – early Jurassic granites that have subduction-related affinity marking the closure of the Mesotethys. The current work focuses on the geochemical markers of late Triassic volcanism to evaluate whether a plume-related magmatic activity was responsible for the creation of the Mesotethys Ocean.

Our preliminary geochemical results indicate that the SiO2 content of basalts is low, ranging from 36.5 to 47.7 wt.%, which classifies the rocks as mafic and ultramafic. The rocks' TiO2 concentration is exceptionally high, ranging from 1.9 to 4.4 wt.%, which is not typical of arc-related basalts and instead resembles oceanic island basalts. Concentration of Al2O3 (7.5-18.8 wt.%), Fe2O3 (8.3-16.3 wt.%), MgO (2.7 – 14.9 wt.%) and CaO (2.5 – 12.4 wt.%) likewise fluctuate in a large range. Alkalis also vary across a wide range (K2O: 0.2 – 3.1 wt.%; Na2O: 1.4 – 5.5 wt.%) and add up to values (1.7 – 7 wt.%) that define the majority of the examined samples (11) as alkali basalts, with three samples plotting below the sub-alkaline – alkaline dividing line. The rocks' relatively high P2O5 (0.2 to 0.6 wt.%) may further reflect their OIB affinity. Normalized to the primitive mantle, trace element patterns on spidergrams reveal a small enrichment of Large-Ion Lithophile Elements and depletion of High-Field Strength Elements. However, positive anomalies in Nb (14.3 – 29 ppm) and Ti rule out subduction as the cause of the rocks' formation. Moreover, high ratios of Nb/La (1.1–1.7) and La/Yb (6.9–15) also support the non-subductional origin of the basalts. Thus, our collected geochemical data reveal a striking similarity to the basalts of oceanic islands.

 

How to cite: Aminov, J., Mikhailenko, D., Odinaev, S., Moazzen, M., Dupont-Nivet, G., Mamadjanov, Y., Stepanov, A., Yogibekov, J., and Ashuraliev, S.: The birth of the Mesotethys ocean recorded in the Southern Pamir Triassic basalts , EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14244, https://doi.org/10.5194/egusphere-egu23-14244, 2023.

EGU23-14296 | ECS | Orals | GD9.1

The devastating 2022 M6.2 Afghanistan earthquake: challenges, processes and implications 

Sofia-Katerina Kufner, Lidong Bie, Ya-Jian Gao, Mike Lindner, Hamidullah Waizy, Najibullah Kakar, and Andreas Rietbrock

On June 21th, a Mw6.2 earthquake struck the Afghan-Pakistan-border-region, an area dominated by partitioned deformation related to the India-Asia collision. Despite its moderate size, 1150 deaths were reported, making the event the deadliest earthquake of 2022 so far. We investigate the event’s rupture processes, aiming to understand what made it that fatal. Our InSAR-constrained slip model and regional moment-tensor inversion reveal a sinistral rupture with maximum slip of 1.8 m at 5 km depth on a N20°E striking, sub-vertical fault. Field observations confirm fault location and slip-sense. Based on our analysis and a global comparison, we suggest that not only external factors (e.g. time of the event and building stock) but also fault-specific factors made the event excessively destructive. Surface rupture was favored by the local rock anisotropy (foliation), coinciding with the fault strike. The distribution of Peak Ground Velocity was governed by the sub-vertical fault. The maximum slip was large compared to other events globally and might have resulted in peak-frequencies coinciding with the resonance-frequency of the local one-story buildings. More generally, our study demonstrates the devastating impact of moderate earthquakes, being small enough to be accommodated by many tectonic structures but large enough to cause significant damage.

How to cite: Kufner, S.-K., Bie, L., Gao, Y.-J., Lindner, M., Waizy, H., Kakar, N., and Rietbrock, A.: The devastating 2022 M6.2 Afghanistan earthquake: challenges, processes and implications, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14296, https://doi.org/10.5194/egusphere-egu23-14296, 2023.

EGU23-14406 | Posters on site | GD9.1

Kinematics of the Pamir orogeny on a lithospheric scale 

Jonas Kley, Edward R. Sobel, Thomas Voigt, Johannes Rembe, and Rasmus Thiede

The south-dipping Benioff zone beneath the Pamir mountains marks the youngest, active slab accommodating India-Asia convergence near the western edge of the Indian indenter (75° E). Seismic tomography suggests the existence of two older slabs farther south, both interpreted as Indian lithosphere detached and sinking: the Tethys slab, broken off around 46 Ma concomitant with early collision and the more northerly and shallower Indian slab, detached around 25 Ma at the longitude considered here (Replumaz et al. 2010). The total length of the three slabs is about 1300 km (Tethys 600 km, India 300 km, Pamir 400 km), substantially less than the distance of more than 2000 km that India has moved north since 46 Ma. This discrepancy implies that either the tomographic record of subduction is incomplete or that Indian mantle lithosphere has underthrust (thin?) Asian lithosphere, with the stacked lithospheres unresolvable by tomography. As a consequence, the rate of slab lengthening and the age of slab initiation in the Pamir are poorly constrained. The absence of asthenosphere between the Pamir slab of Asian provenance and supposedly Indian mantle lithosphere above it suggests that India´s leading edge is advancing at the same rate as rollback of the Pamir slab. This rate could be as high as full India-Asia convergence at ca. 35 mm/yr (Kufner et al. 2016) or as low as present-day Pamir-foreland convergence at 15 mm/yr, corresponding to ages of the 300-400 km long slab of 9-12 Ma or 20-27 Ma. The wide range of possible ages makes it difficult to tie slab initiation to specific geologic events during the Pamir orogeny. Other evidence suggests that the direction and rate of India-Asia convergence may be poor predictors of mantle lithospheric motion above the slab: The shortening direction in the Tajik foreland thrust belt is WNW, and foreland shortening decreases northeastward from a maximum of 150 km in the Tajik belt to 75 and 30 km in the Alai Valley and westernmost Tarim. Slab length follows a similar trend, with a steeply east-dipping Benioff zone in the west and a more gently south-dipping one in the north, traced by earthquakes to depths of 250 km and 150 km, respectively. Also, the longest, NE-striking segment of the slab is relatively straight in map view and parallel to the axis of thickest crust (Schneider et al. 2019). These observations are difficult to reconcile with northward convergence. Instead, they suggest overall northwestward convergence during the Pamir orogeny. We speculate that this could be due to westward deflection at depth of an Indian lithosphere promontory interacting with the NW-trending edge of thick Tarim lithosphere.

Kufner, S.-K., et al. (2016). Deep India meets deep Asia: Lithospheric indentation, delamination and break-off under Pamir and Hindu Kush (Central Asia). Earth and Planetary Science Letters 435: 171-184.

Replumaz, A., et al. (2010). Indian continental subduction and slab break-off during Tertiary collision. Terra Nova 22: 290-296.

Schneider, F. M., et al. (2019). The Crust in the Pamir: Insights from Receiver Functions. Journal of Geophysical Research: Solid Earth 124(8): 9313-9331.

How to cite: Kley, J., Sobel, E. R., Voigt, T., Rembe, J., and Thiede, R.: Kinematics of the Pamir orogeny on a lithospheric scale, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14406, https://doi.org/10.5194/egusphere-egu23-14406, 2023.

EGU23-14762 | ECS | Posters virtual | GD9.1

Understanding Magma Nature of Post-Collisional Alkaline Granites Around Uludag (NW, Turkiye): Implications for New Geodynamic Scenarios 

Huseyin Kocaturk, Mustafa Kumral, Ali Tugcan Unluer, Mustafa Kaya, Merve Sutcu, Zeynep Doner, Huseyin Sendir, and Amr Abdelnasser

Magmatic Suite around Uludag Massif contains some alkaline (A-type or highly fractionated felsic I-type) granites that developed in post-collisional plate tectonic conditions. Their genesis involved by Eocene calc-alkaline and Oligocene strongly peraluminous granite magmatism. Their emplacement is linked to strike-slip shear movements and/or extension that occur after the Neo-Tethys collisional events. These granites are spatially related to the Izmir-Ankara Suture Zone (IASZ). The majority of these alkaline granites are formed by middle or lower crustal anatexis, extracted melt restite of I-type granites. Previously non-melted mafic meta-tonalites are considered to represent their source rocks. The mechanism for the required high melting temperatures will be well explained by our new model. However, models based on partial delamination of the base of the lithosphere or asthenospheric upwelling due to steepening and breaking of the subducted Tethyan oceanic slab are still consistent. As is the case for many well-known post-collisional regimes, transpressional to transtensional and/or moderately extensional tectonism predominates throughout to region. Although crustal thickening does not appear evident as in the notable arcs and microcontinent collisions, uplifting of particular regions associated with post-collisional calc-alkaline granite emplacement is observable. Understanding the nature of post-collisional highly fractionated granites around Uludag will extend the view of how Western Anatolia was affected by Alpine Orogeny in the Tethyan Realm. The challenge is drawing the geochemistry line for the tectono-magmatic setting between post-collision to post-orogenic. Describing the nature of alkaline magmatism through late-stage orogeny to intra-plate setting may need to be more precise because of trace elements' overprinting. However, a holistic view of the magmatism and source rocks points out a synchronous crustal growth and crustal rework. Our new possible geodynamic scenario suggests crust–mantle decoupling combined with slab retreat results in thinning of the lithospheric mantle. The 75-80 km decoupling depth calculated from obducted blueschists of Tavsanlı Zone confirms the plate motions controlled thermal relaxation temperature is enough at the base of the lithosphere for the geotherm-induced magma generation for the Tavsanlı Zone.

How to cite: Kocaturk, H., Kumral, M., Unluer, A. T., Kaya, M., Sutcu, M., Doner, Z., Sendir, H., and Abdelnasser, A.: Understanding Magma Nature of Post-Collisional Alkaline Granites Around Uludag (NW, Turkiye): Implications for New Geodynamic Scenarios, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14762, https://doi.org/10.5194/egusphere-egu23-14762, 2023.

Gneiss dome records the deformation and tectonothermal evolution of orogenic belt and lithosphere, which provides a perfect window for studying of collisional orogenic process and tectonic evolution. The North Himalayan Gneiss Domes, trending East-West, as one of the important tectonic units of the Himalayan orogen, experienced deep materials uplifting and lateral flow. Based on the above observations, we suggest that the RBD experienced 4 periods of tectonothermal evolutions (D1-D4) and 2 stages of tectonic background transformations. (1) D1: Crustal thickening, regional metamorphism and anatexis occurred during plate collision in the Eocene (46.3-40.6 Ma). (2) D2: Partial melting of middle-lower crust result in the development of channel flow which reduced the rheology of the middle-lower crust and led to the onset of the STDS and crustal thinning in the early Miocene (26.1-21.0 Ma). Therefore, the tectonic background transformed from N-S compression to N-S extension (the first tectonic background transformation). (3) D3: The ongoing of the STDS contribute to the decompression melting, small-scale diapirism and accompanied magmatic emplacement. The activity of the NSTRs started at mid-Miocene (12.0-10.2 Ma), the tectonic background shifted from N-S extension to E-W extension (the second tectonic background transformation). (4) D4: +With NSTRs’ activity peaking in the late Miocene (8.7-7.6 Ma), further crustal thinning, decompression melting and leucogranite intrusion occurred under extensional condition, which result in the contact metamorphism, and established the final tectonic framework, geometry, and thermalstructure of the RBD. The tectonothermal evolution of the RBD supports the middle-lower crustal channel flow orogenic model.

Fluid inclusion and oxygen isotope data for quartz veins in the Ramba Dome in the North Himalayan Gneiss Domes show limited variations in individual quartz veins, but δ18Oquartz values vary from 12.07 to 18.16‰ (V-SMOW) among veins. The corresponding δ18Ofluid values range from 7.71 to 13.80‰, based on equilibrium temperatures obtained from fluid inclusions. From the footwall to the detachment zone, δ18Ofluid values exhibit a broadly decreasing trend and indicate that the STDS dominated the fluid flux pathway in the crust, with more contributions of meteoric water in the detachment zone. We further quantified the contribution of meteoric fluids to 8–27% using a binary end-member mixing model. These data imply that the fluids were predominantly metamorphic/ magmatic in origin, and were mixed with infiltrating, isotopically light, meteoric water during extensional detachment shearing of the STDS. Based on the above research, we propose that metamorphic dehydration of lower crust and atmospheric precipitation "stimulate" new activity of Himalayan mountain building.

How to cite: Bo, Z.: The multistage extensional structure and excitation mechanism of Himalayan orogeny, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15394, https://doi.org/10.5194/egusphere-egu23-15394, 2023.

EGU23-16615 | Orals | GD9.1

Crustal Structure of the Jammu and Kashmir Himalaya 

Supriyo Mitra, Swati Sharma, Debarchan Powali, Keith Priestley, and Sunil Wanchoo

We use P-wave receiver function (P-RF) analysis of broadband teleseismic data recorded at twenty stations spanning the Jammu-Kishtwar Himalaya, Pir Panjal Ranges, Kashmir Valley, and Zanskar Ranges in Northwest Himalaya, to model the seismic velocity structures of the crust and uppermost mantle. Our network extends from the Shiwalik Himalaya (S) to the Tethyan Himalaya (N), across major Himalayan thrust systems and litho-tectonic units. We perform depth–Vp /Vs (H-K) stacking of P-RF, common conversion point (CCP) stacking along 2D profiles and joint inversion with surface wave dispersion data. H-K analysis reveals increasing average crustal thickness from the foreland (∼40 km) to the hinterland (∼65 km), with felsic- to-intermediate (Vp /Vs of 1.71–1.80) average crustal composition. In CCPs the Indian crust Moho is marked by a large positive impedance contrast boundary, and the Main Himalayan Thrust (MHT) by a negative phase, indicating a low velocity layer (LVL). The underthrust Indian crust (between the MHT and Moho) has an average thickness of ∼40 km and the Moho dips northward at ∼7–9◦ . Moho flexure (or possible off-set) are observed in across-arc profiles, beneath the Shiwalik Himalaya, Higher Himalaya and the Kishtwar window. The Moho is remarkably flat at ∼55 km beneath the Pir Panjal Ranges and the Kashmir Valley. North of the Kishtwar window (E) and Kashmir Valley (W) the Moho dips steeply underneath the Tethyan Himalaya/Zanskar Ranges from ∼55 km to ∼65 km. The MHT LVL is at a depth of ∼8 km beneath the Shiwalik Himalaya, and dips gradually northeast at ∼7–9◦ , to reach a depth of ∼25 km beneath the Higher Himalaya. The MHT is marked by a frontal ramp beneath the Kishtwar window (E) and north of the Kashmir Valley (W). The MKT, MBT and MCT are marked by LVLs which splay updip from the MHT. To study the 3D variation of the crustal structure, we grid the region into 0.1◦ square grids and jointly model the P-RFs within each grid with Rayleigh wave dispersion data, obtained from regional tomography. The 3D models obtained from this analysis provide variations in Vs and Moho depth. The Kashmir Valley and Zanskar Ranges are underlain by the highest average crustal Vs followed by the Pir-Panjal Ranges. These are also regions of the thickest crust. The Shiwalik Himalaya is underlain by the slowest average Vs , with lateral variations along the MKT, Reasi Thrust and the Kotli Thrust. These are also regions of thinnest crust (~40 km). A remarkable lower Vs region extends SW-NE from Jammu to the Kishtwar window, along the reentrants of the MHT, MBT and MCT. This marks a strong E-W lateral variation in crustal Vs , Moho depth and a possible lateral ramp on the MHT, also highlighted by small-to-moderate earthquake clusters.

How to cite: Mitra, S., Sharma, S., Powali, D., Priestley, K., and Wanchoo, S.: Crustal Structure of the Jammu and Kashmir Himalaya, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16615, https://doi.org/10.5194/egusphere-egu23-16615, 2023.

EGU23-17000 | Posters virtual | GD9.1

Paleo-Tethyan ocean evolution in the East Kunlun Orogen, northern Tibetan plateau 

Ruibao Li, Xianzhi Pei, Zuochen Li, Lei Pei, Guochao Chen, Zhanqing Liu, Youxin Chen, Chengjun Liu, and Meng Wang

The East Kunlun Orogen on the northern margin of the Tethyan orogenic system records a history of Gondwana dispersal and Laurasian accretion. Based on a synthesis of sedimentary, structural, lithological, geochemical, and geochronological data from the East Kunlun Orogen and adjacent regions, we discusses the spreading and northward consumption of the Paleo-Tethys Ocean during Late Paleozoic-Early Mesozoic times. The main evolutionary stages are: (1) During Carboniferous to Middle Permian, the Paleo-Tethys Ocean (Buqingshan Ocean) was in an ocean spreading stage, as suggested by the occurrence of Carboniferous MORB-, and OIB-type oceanic units and Carboniferous to Middle Permian Passive continental margin deposits; (2) The Buqingshan Ocean subducted northward beneath the East Kunlun Terrane, leading to the development of a large continental magmatic arc (Burhan Budai arc) and forearc basin between ~270-240 Ma; (3) During the late Middle Triassic to early Late Triassic (ca. 240-230 Ma), the Qiangtang terrane collided with the East Kunlun-Qaidam terranes, leading to the final closure of the Buqingshan Ocean and occurrences of minor collision-type magmatism and potentially inception of the Bayan Har foreland basin; (4) Finally, the East Kunlun Orogen evolved into a postcollisional stage and produced major magmatic flare-ups and polymetallic mineral deposits between Late Triassic to Early Jurassic (ca. 230-200 Ma), which is possibly related to asthenospheric mantle upwelling induced by delamination of thickened continental lithosphere and partial melting of the lower crust. Accordingly, we propose that the Wilson cycle-like processes controlled the Late Paleozoic-Early Triassic tectonic evolution of East Kunlun, which provides significant implications for the evolution of Paleo-Tethys Ocean.

How to cite: Li, R., Pei, X., Li, Z., Pei, L., Chen, G., Liu, Z., Chen, Y., Liu, C., and Wang, M.: Paleo-Tethyan ocean evolution in the East Kunlun Orogen, northern Tibetan plateau, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17000, https://doi.org/10.5194/egusphere-egu23-17000, 2023.

EGU23-17021 | ECS | Orals | GD9.1

Rheological heterogeneities control the non-progressive uplift of the young Iranian plateau 

Yifan Gao, Ling Chen, Jianfeng Yang, and Kun Wang

The Iranian plateau is at the early stage of plateau development and intracontinental deformation in response to the Arabia-Eurasia collision. Its compressive deformation is concentrated in the northern plateau but skips the central counterpart, challenging the common views envisaging the progressive uplift from the collisional front to the hinterland. Based on three-dimensional, crustal-scale numerical models, we present how the rheological heterogeneities common in continents control the deformation of the young Iranian plateau. The weak northern plateau ensures itself a preferential zone in accommodating continental collision. The N-S strike-slip faults within the non-rigid central plateau, formed along the boundaries between the tectonic units with rheological contrast, suppress the shortening of the central plateau while further accentuating the compressive deformation of the northern plateau. Our results suggest a non-progressive intracontinental deformation pattern where rheological boundaries and mechanically weak zones, not necessarily those close to collisional fronts, preferentially accommodate continental convergence.

How to cite: Gao, Y., Chen, L., Yang, J., and Wang, K.: Rheological heterogeneities control the non-progressive uplift of the young Iranian plateau, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17021, https://doi.org/10.5194/egusphere-egu23-17021, 2023.

EGU23-17123 | Orals | GD9.1 | Highlight

The Nature of the Cimmerian Continent 

A.M. Celâl Şengör, Demir Altıner, Cengiz Zabcı, Gürsel Sunal, Nalan Lom, and Tayfun Öner

We have compiled local stratigraphic, structural, palaeobiogeographical and reliable isotopic age data from the remnants of the Cimmerian Continent from western Turkey to Malaysia with a view to understanding its nature and evolution. Our principal conclusions are the following:

1) The entire northwestern margin of Gondwana-Land was an extensional Pacific-type continental margin much like the present-day western Pacific during the Permo-Carboniferous characterised by typical Gondwana-Land biotas.

2) Beginning with the Permian, the Cimmerian Continent began to pull away from the northeastern margin of Gondwana-Land from Turkey in the west to Malaysia in the east, although in Thailand and Malaysia rifting may have started already during the earlierst Carboniferous.

3) Synchronously with this rifting, the Wašer/Rushan-Pshart/ Banggong Co-Nu Jiang ocean, herein called the Maera, began opening in the Permian isolating the Lhasa/Victoria Land block from the rest of the Cimmerian Continent. In fact, the Himalayan sector of the Neo-Tethys may have opened slightly later than the Maeran ocean.

4) Central Iran consisted of two parts: the northest Iranian extensional area and the multi-block Central Iranian Continent consisting of the Yazd, Posht-e Badam, Tabas and the Lut blocks. These blocks were stacked against one another horizontally as a consequence of the Cimmeride collisions in the Pamirs and Afghanistan while Albors was rifted away from the Sanandaj-Sirjan zone, as the latter was also rifting away from Gondwana-Land, stretching northwestern Iran into its present-day triangular shape.

5) Significant arc magmatism characterised the entire Cimmerian continent from one end to the other during the Permian to the Liassic interval.

We thus maintain that the Cimmerian Continent was the site of supra-subduction extension throughout its history until it collided with Laurasia during the medial to late Jurassic. In some areas the collision may have been earlier. The Maeran ocean remained opened until the Aptian. The best analogue for the evolution of the Cimmerian Continent and its attendant small oceans is the present-day southwest Pacific arc/marginal basin systems from the Tonga-Kermadec system in the east as far west as Australia.

How to cite: Şengör, A. M. C., Altıner, D., Zabcı, C., Sunal, G., Lom, N., and Öner, T.: The Nature of the Cimmerian Continent, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17123, https://doi.org/10.5194/egusphere-egu23-17123, 2023.

EGU23-1069 | ECS | Orals | SM2.1

Seismic Anisotropy from 6C Observations 

Le Tang, Heiner Igel, and Jean-Paul Montagner

A new approach is proposed for measuring the local dispersion curves of surface waves in weakly anisotropic media using a single, multi-component station, which consists of translation and rotation or strain. We directly extract the local azimuth-dependent phase velocity of the Rayleigh wave from the 6C amplitude ratio using seismic arrays deployed in Southern California. The extracted dispersion curves match well with the theoretical 2φ azimuthal anisotropy term. And the estimated fast wave direction is also consistent well with results calculated from SKS and beamforming methods which demonstrates the feasibility of studying local seismic anisotropy directly from 6C amplitude observations.

How to cite: Tang, L., Igel, H., and Montagner, J.-P.: Seismic Anisotropy from 6C Observations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1069, https://doi.org/10.5194/egusphere-egu23-1069, 2023.

Distributed Acoustic Sensing (DAS) in geothermal wells is a particularly attractive technology to implement as part of routine seismic monitoring of geothermal plant operations. It brings a large network of sensors close to the monitoring target – the operated reservoir – increasing the sensitivity towards low magnitude events and allows the application of processing procedures inspired by large network or array processing. However, the technical management of the large flow of produced data and the suitability of the strain-rate acquisitions to monitor locally induced seismicity was yet to be fully assessed.

We present the results of a continuous 6-month monitoring period that aimed at testing an integrated system designed to manage the acquisition, the processing and the saving of DAS data collected from behind casing at the Schäftlarnstraße (SLS) geothermal project (Munich, Germany). The data management system links the existing on-site infrastructure to a cloud Internet-of-Things (IoT) platform integrated into the company’s IT infrastructure. The cloud platform has been designed to deliver both a secure storage environment for the DAS records and optimized computing resources for their continuous processing.

With a special focus on seismic risk mitigation, we investigate the potential of the monitoring concept to provide sensitive detection capabilities, despite operational conditions, while ensuring efficient data processing in order to strive for real-time monitoring. Further analysis of the records confirm additional logging capabilities of borehole DAS. We also evaluate the ability of DAS to provide reliable seismic source description, in particular in terms of location, moment magnitude, and stress drop.

Using two detected local seismic events, we demonstrate the relevance of the system for monitoring the SLS-site in an urban environment, while complementing advantageously the surface seismometer-based monitoring network.

How to cite: Azzola, J. and Gaucher, E.: Continuous seismic monitoring of a geothermal project using Distributed Acoustic Sensing (DAS): a case study in the German Molasse Basin., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1292, https://doi.org/10.5194/egusphere-egu23-1292, 2023.

EGU23-2091 | Orals | SM2.1 | Highlight

Using DAS-fibres at ocean floor and lunar surface 

Martin Landrø

We have used two seabed fibre optic cables connecting Ny Ålesund and Longyearbyen at Svalbard, North of Norway, to track several whales for several weeks. Exploiting that we have access to two fibres we demonstrate that it is possible to track several whales in a fairly large region. It is possible to create sound records of whales that can be used for identification and discrimination between various species. The localization method has also been tested by using a small air gun to confirm the localization method used for whales. Examples of earthquake recordings, ship traffic monitoring and distant storms will be shown.

Based on the rapid and promising developments within DAS technology, there is a growing interest for using fibre optic cables at the moon. Some challenges and possibilities related to Lunar DAS applications will be discussed.

How to cite: Landrø, M.: Using DAS-fibres at ocean floor and lunar surface, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2091, https://doi.org/10.5194/egusphere-egu23-2091, 2023.

EGU23-2814 | Orals | SM2.1

Divergence-based estimation of Rayleigh wave dispersion curves 

Pascal Edme, David Sollberger, Tjeerd Kiers, Cedric Schmelzbach, Felix Bernauer, and Johan Robertsson

We present a novel seismic acquisition and processing technique to efficiently evaluate the local dispersion curves of Rayleigh waves for subsequent inversion of shear velocities and near-surface characterization.

The proposed approach consists of computing the ratio between the (time derivated) horizontal spectra H(f)=(∂tVx(f)2+∂tVy(f)2)1/2  and the pseudo-divergence spectra D(f), with D being the sum of the horizontal gradients of the horizontal components (i.e. D=∂xVx+∂yVy).

The processing method itself is comparable to the commonly used H/V approach, except that the H/D spectral ratio provides a direct estimate of the frequency-dependent phase velocities cR(f)  instead of the site frequency amplification(s). This is demonstrated using synthetic data.

We describe how the D component can be obtained in practice, i.e. by finite-differencing closely spaced horizontal phones or potentially using Distributed-Acoustic-Sensing (DAS) and fibre-optic deployed at the surface. Some limitations about wavelength dependency and impact of Love waves are discussed, as well as potential mitigation measures.

A field test on several hours of ambient noise data collected in Germany with multi-component geophones results in realistic values of Rayleigh wave velocities ranging from ~770 m/s at 10 Hz to ~500 m/ at 30 Hz. Thanks to the local and omni-directional nature of the estimation, the minimal number of required channels and the applicability to ambient noise, we believe that the proposed H/D method can be an attractive alternative to expensive array-based techniques.

How to cite: Edme, P., Sollberger, D., Kiers, T., Schmelzbach, C., Bernauer, F., and Robertsson, J.: Divergence-based estimation of Rayleigh wave dispersion curves, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2814, https://doi.org/10.5194/egusphere-egu23-2814, 2023.

EGU23-3061 | Orals | SM2.1

Nano-strain resolution fiber-optic Fabry-Perot sensors based measuring systems 

Simon Pevec and Denis Donlagic

A work describes a deeply etched, long active length, high sensitivity short Fabry-Perot cavity nano-strain resolution sensor. The presented sensors exhibit high spectral sensitivity, low intrinsic temperature sensitivity which is for about 40 times lower than in case of FBG, small size and mounting comparable to conventional Fiber Bragg gratings. The sensor high potential is not only high sensitivity and low temperature intrinsic sensitivity, but also in short cavity length and its tunability, which can be simply accomplished in one production step. This brings versatility in interrogation with different general purpose and cost-efficient VIS-NIR widely available linear detector array-based spectrometers, while still providing strain sensing resolution within the range of few 10 nε. A strain resolution of 20 to 70 nε was demonstrated when using a cost-efficient VIS spectrometer. Furthermore, the sensor structure can be combined with multimode telecom lead-in fibers and low-cost broadband LEDs intended for automotive/lightning applications, which allow production of cost efficient solutions.

How to cite: Pevec, S. and Donlagic, D.: Nano-strain resolution fiber-optic Fabry-Perot sensors based measuring systems, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3061, https://doi.org/10.5194/egusphere-egu23-3061, 2023.

EGU23-3437 | ECS | Posters on site | SM2.1

Monitoring temperature at the ocean seafloor with fibre optic cables and DAS 

Julián Pelaez Quiñones, Anthony Sladen, Aurelien Ponte, Itzhak Lior, Jean-Paul Ampuero, Diane Rivet, Samuel Meulé, Frédéric Bouchette, Ivane Pairaud, and Paschal Coyle

Ocean water temperature measurements are fundamental to atmospheric and ocean sciences. Obtaining them, however, often comes along with major experimental and logistic challenges. Except for the uppermost ocean surface temperature, which can be measured from satellites, temperature data of the ocean is often poorly sampled or nonexistent, especially in deep-water regions.

Although Distributed Acoustic Sensing (DAS) technology has become popular because its high sensitivity to strains and mechanical vibrations, our work focuses on its usage on tens-of-kilometer-long underwater fibre-optic (FO) telecommunication cables to measure temperature anomalies at the seafloor at millikelvin (mK) sensitivity. This is possible because of the lack of dominant strain signals at frequencies less than about 1 mHz, as well as the poor coupling of the fibre with these signals while remaining highly sensitive to slow ambient temperature variations that locally affect its optical path length. DAS allows us to observe significant temperature anomalies at the continental shelf and slope of the Mediterranean sea, South of Toulon, France over periods of several days, with variability remaining relatively low at the deep ocean. By means of this approach, oceanic processes such as near-inertial internal waves and upwelling can be monitored at unprecedented detail.

Our observations are validated with oceanographic in-situ sensors and alternative Distributed Fibre Optic Sensing (DFOS) technologies established for temperature sensing. We outline key advantages of DAS thermometry over the aforementioned sensors in terms of spatial coverage, sensitivity, versatility and highest attainable frequency. At the current state of the art, DAS can only measure temperature anomalies as opposed to absolute temperature, a drawback that could be compensated via single temperature calibration measurements.

How to cite: Pelaez Quiñones, J., Sladen, A., Ponte, A., Lior, I., Ampuero, J.-P., Rivet, D., Meulé, S., Bouchette, F., Pairaud, I., and Coyle, P.: Monitoring temperature at the ocean seafloor with fibre optic cables and DAS, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3437, https://doi.org/10.5194/egusphere-egu23-3437, 2023.

EGU23-3955 | ECS | Orals | SM2.1

Using Distributed Acoustic Sensing to Monitor and Investigate Eruptive Events at Stromboli Volcano, Italy 

Francesco Biagioli, Jean-Philippe Métaxian, Eléonore Stutzmann, Maurizio Ripepe, Alister Trabattoni, Pascal Bernard, Roberto Longo, Gianluca Diana, Lorenzo Innocenti, Yann Capdeville, Marie-Paul Bouin, and Giorgio Lacanna

Volcano seismology is essential for understanding, monitoring, and forecasting eruptive events. The use of distributed acoustic sensing (DAS) technology can be particularly useful for this purpose because of its high temporal and spatial resolution, which may help to overcome the challenges of deploying and maintaining seismic arrays on volcanoes.

Between 2020 and 2022, we installed 4 km of optical fibre on Stromboli volcano, Italy, whose persistent activity is well-suited for investigating the related dynamic strain rate. The cable was buried at a depth of 30 cm and the layout geometry was designed to provide wide coverage while being constrained by natural obstacles and topographical features. Seismometers were also installed along the fibre. DAS data were collected using a Febus A1-R interrogator, and the acquisition period increased from one week in 2020 to over four months in 2022. We recorded volcanic tremor, ordinary explosions (several per hour), two major explosions in 2021 and 2022, and the entire sequence of a pyroclastic flow in 2022. 

DAS and seismic data show good agreement in both time and frequency domains after converting strain rate to velocity and vice versa using different methodologies. Beamforming of DAS data shows a dominant signal in the 3-5 Hz frequency band coming from the active craters. We will also present preliminary results of major explosions and pyroclastic flow. This experiment demonstrates that DAS can be used for monitoring volcanic activity.

How to cite: Biagioli, F., Métaxian, J.-P., Stutzmann, E., Ripepe, M., Trabattoni, A., Bernard, P., Longo, R., Diana, G., Innocenti, L., Capdeville, Y., Bouin, M.-P., and Lacanna, G.: Using Distributed Acoustic Sensing to Monitor and Investigate Eruptive Events at Stromboli Volcano, Italy, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3955, https://doi.org/10.5194/egusphere-egu23-3955, 2023.

EGU23-4256 | ECS | Posters on site | SM2.1

Groundwater monitoring using fibre-optics and DAS: Application to the Lyon water catchment area. 

Destin Nziengui Bâ, Olivier Coutant, and Camille Jestin

Water resource management is a crucial socio-economic issue that requires developing high-resolution monitoring techniques, including non-invasive geophysical methods. Among them, passive seismic interferometry takes advantage of natural ambient seismic noise to recover the slight variations of the seismic wave velocity induced by changes in the groundwater level. In this study, we present the time and space monitoring of groundwater changes artificially generated by infiltration ponds at the exploitation field of Crépieux-Charmy (Lyon, France).  We deployed 3km of optical fibre and a dense array of fifty 3C geophones around infiltration basins. We recorded several cycles of filling-emptying with a DAS using a 2m spatial sampling (i.e., 1500 fibre sensors). The recorded signals are mainly associated with local anthropogenic noise (highways, trains, pumping, etc.). We could track seismic velocity variations with high temporal and spatial resolutions using ambient noise interferometry techniques. These variations are associated with the interaction between the water diffused from the basins and water table variations. This dynamic information helps understand and model water exchanges on the ground. The study confirms the possibility of groundwater monitoring using DAS records of ambient noise for seismic interferometry in a highly urbanized zone.

How to cite: Nziengui Bâ, D., Coutant, O., and Jestin, C.: Groundwater monitoring using fibre-optics and DAS: Application to the Lyon water catchment area., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4256, https://doi.org/10.5194/egusphere-egu23-4256, 2023.

EGU23-4769 | ECS | Orals | SM2.1

Arrival Picking for Distributed Acoustic Sensing seismic based on fractional lower order statistics 

Xiang Wang, Honghui Wang, Yuhang Wang, Shangkun Zeng, and Yiru Wang

In recent years, fiber-optic distributed acoustic sensing (DAS) has been gradually applied to seismology because of its long-distance and dense observation capability. It is a great challenge to effectively process the massive seismic data recorded by DAS. At present, the seismic data processing methods based on deep learning have achieved great success, especially in the tasks of seismic detection and arrival-time picking. However, due to the differences between DAS and geophone, such as sensing principles, spatial and temporal sampling rates, and noise intensity. The seismic arrival time picking model based on deep learning, which is trained by geophone seismic data with low spatial and temporal sampling rates and low noise intensity, severely degrades in performance on DAS seismic data with high spatial and temporal sampling rates and high noise intensity. In addition, a new seismic arrival time picking model is trained by fully supervised learning, which usually requires a large number of seismic data with accurate labels. However, the huge cost of manual picking and the lack of effective automatic picking models make it very difficult to build large-scale DAS seismic data sets with accurate labels. Therefore, it is very difficult to build an arrival time picking model based on fully supervised learning for DAS seismic data.

In this study, we propose a DAS seismic arrival time picking method based on fractional lower order statistics. Based on the difference of probability density function between noise and seismic signal, the proposed method uses alpha-stable distribution modeling noise (generally follow a Gaussian distribution) and seismic signal (generally follow a non-Gaussian distribution), and uses fractional lower order statistics under the assumption of alpha-stable distribution as the characteristic function to pick the arrival time.

Synthetic and actual DAS data tests show that the proposed method has better performance and robustness to random noise than other methods based on characteristic functions, such as STA/LTA, AR-AIC and kurtosis. Since the actual DAS seismic data has no ground truth of arrival time, we have further the performance of the proposed method on the geophone seismic data set. The proposed method provides better results on geophone seismic data and the data after up-sampling them to the typical time sampling rate of DAS.

How to cite: Wang, X., Wang, H., Wang, Y., Zeng, S., and Wang, Y.: Arrival Picking for Distributed Acoustic Sensing seismic based on fractional lower order statistics, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4769, https://doi.org/10.5194/egusphere-egu23-4769, 2023.

EGU23-5455 | ECS | Posters on site | SM2.1

Active-source seismic experiments with DAS for monitoring reservoir rock in underground laboratories 

Katinka Tuinstra, Antonio Pio Rinaldi, Federica Lanza, Alba Zappone, Andreas Fichtner, and Stefan Wiemer

Underground laboratories have become indispensable in the understanding of physical processes during e.g., hydraulic stimulation and seismic monitoring of deep geothermal reservoirs or CO2 storage target reservoirs. They provide a test bench and constitute the bridge between small-scale laboratory studies and full-scale pilot sites. Here, we present results from multiple active source seismic campaigns in one of the Swiss underground laboratories: the Mont Terri Rock Laboratory. Here, DAS fibres are cemented behind the casing of multiple monitoring boreholes and active shots are taken with a P-wave sparker. This dense array of active seismic measurements enables us to obtain a baseline characterisation of the P-wave velocity of the rock before any activity (e.g., injection) takes place. During stimulations, dynamic measurements with an active sparker source are recorded, followed by a time-lapse monitoring approach where seismic measurements are collected through active seismic campaigns in set time intervals in the months after stimulations. In this way we can create high-resolution, four-dimensional monitoring and characterisations of the rock body and potential earthquakes during the full monitoring period. We show different configurations and measurements settings with their effect on the DAS recordings of active signals.

How to cite: Tuinstra, K., Rinaldi, A. P., Lanza, F., Zappone, A., Fichtner, A., and Wiemer, S.: Active-source seismic experiments with DAS for monitoring reservoir rock in underground laboratories, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5455, https://doi.org/10.5194/egusphere-egu23-5455, 2023.

EGU23-5701 | ECS | Posters on site | SM2.1

Investigating Vibroseis Sweeps using 6 Rotational Sensors in Fürstenfeldbruck, Germany 

Gizem Izgi, Eva Eibl, Frank Krüger, and Felix Bernauer

Rotational motions can be recorded directly or derived from translational motion recordings. Fairly new rotational sensors allow seismologists to directly record and investigate rotational motions. In order to further investigate and compare recently developed rotational sensors an experiment was made in Fürstenfeldbruck. Within this scope, a vibroseis truck was operated starting from 20 November 2019, 11:00 UTC until 21 November 2019, 14:00 UTC. We recorded 480 Sweep signals at 160 different locations. The truck was operating at 30%, 50%, and 70% relative to a peak force output of 276 kN exciting the ground vertically and each sweep lasted 15 seconds starting with 7 Hz increased up to 120 Hz. We derived back azimuths of each sweep from 6 rotational sensors and calculated root mean squares of each component. We observed that within the first day, the North component of all sensors recorded the largest ground motion energy SV type of energy is dominant. The sweep sources were distributed over two North–South profiles and two East–West profiles.  While the truck moved to the east and its location moved from west to south of the rotational sensors, the signals dominate more and more on the East component.. From our preliminary results, we state that although having different signal to noise ratios all rotational sensor calculated the direction of each sweep. Thus, we can follow the movements of vibroseis truck using all rotational sensors.

How to cite: Izgi, G., Eibl, E., Krüger, F., and Bernauer, F.: Investigating Vibroseis Sweeps using 6 Rotational Sensors in Fürstenfeldbruck, Germany, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5701, https://doi.org/10.5194/egusphere-egu23-5701, 2023.

EGU23-5955 | ECS | Orals | SM2.1

Two-dimensional phase unwrapping algorithm aided high-precision source positioning with DAS 

Jianhui Sun, Yuyao Wang, Jialei Zhang, Anchi Wan, Shibo Zhang, Zhenyu Ye, Fulie Liu, Gulan Zhang, and Zinan Wang

Seismic monitoring requires high temporal-spatial resolution and low deployment cost. Distributed acoustic sensing (DAS), as an emerging sensing technology for recording seismic data in recent years, can leverage communication cables for seismic monitoring, providing strong support for more intensive and real-time observation of geological activity. However, the traditional DAS phase unwrapping algorithms (PUAs) derived from Itoh requires the phase difference of adjacent pixels to be less than π, and thus make mistakes in the case of severe noise or large disturbance. In this paper, to the best of our knowledge, two-dimensional (2D) PUA is used to obtain seismograms in DAS for the first time. Satisfactory phase unwrapping is achieved by the 2D PUA method based on the transport of intensity equation (TIE), due to its robustness and noise immunity. Dynamic strain measurements in 80 m straight fiber-optic cable using homemade high-performance DAS, combined with TIE-based 2D PUA produce high-quality seismograms. Time Difference of Arrival (TDOA) Algorithm is applied based on the sensing signal of reliable channels in the seismograms, realizing the high-precision localization of the source. 2D PUAs apply to all phase-demodulation-based sensing techniques and are suitable for recovering spatially correlated objects such as seismic waves, thus having great potential in the field of seismic monitoring.

How to cite: Sun, J., Wang, Y., Zhang, J., Wan, A., Zhang, S., Ye, Z., Liu, F., Zhang, G., and Wang, Z.: Two-dimensional phase unwrapping algorithm aided high-precision source positioning with DAS, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5955, https://doi.org/10.5194/egusphere-egu23-5955, 2023.

EGU23-6189 | ECS | Orals | SM2.1

Contribution of spatial features for classifying seismic events from Distributed Acoustic Sensing (DAS) data streams 

Camille Huynh, Clément Hibert, Camille Jestin, Jean-Philippe Malet, and Vincent Lanticq

Distributed Acoustic Sensing (DAS) is an acoustic sensor instrument that turns a single optical fiber into a dense array of thousands of equally spaced seismometers. Geoscientists and companies have an interest in investing in DAS technologies for better understanding the Earth by observing natural and anthropogenic seismic events or assisting in large infrastructure monitoring with low installation and maintenance costs. However, this type of instrument generates a significantly larger amount of data than conventional seismometers, data that can be complex to store, exploit and interpret.

Several strategies for classifying seismic events from fiber-optics DAS data exist in the scientific literature. Conventional approaches rely on the use of features that describe the waveforms and frequency content of signals recorded individually at virtual stations along the fiber; they do not integrate the spatial density of information permitted by DAS. Several studies on dense seismological arrays have introduced similarity measures between the different time series data such as cross-correlations, dynamic time warping (DTW) or compression-based dissimilarity.

This study aims to quantify the contribution of spatial features for DAS data streams classification. We have chosen to explore spatial features related to both standard statistical measures (e.g., spatial mean, median, skewness, kurtosis), and advanced signal processing measures (e.g., auto-correlations, cross-correlations, DTW). This set of measures allows enriching a list of already used time series features which includes waveform, spectrum and spectrogram. A Random Forest (RF) classifier is then trained, and a Random Markov Field (RMF) algorithm is used after classification to account for redundant spatial and temporal information.

The evaluation of the spatial feature contribution is based on the output of the RF-RMF processing chain. Anthropogenically-triggered seismic data were acquired at the FEBUS Optics test bench. We consider five seismic sources: footsteps, impacts, excavators, compactor and fluid leaks. A class of noise is added as the RF-RMF algorithm is developed for processing DAS streams inherently affected by  noise.  Accurate  classification results can be obtained using only time features, and ongoing tests show a 2% increase in the correct classification rate with the use of both time and spatial features. The improvement allowed by the addition of spatial features is tangible but limited on our test dataset, but we think it should have a much greater impact on natural sources and we will discuss this perspective.

How to cite: Huynh, C., Hibert, C., Jestin, C., Malet, J.-P., and Lanticq, V.: Contribution of spatial features for classifying seismic events from Distributed Acoustic Sensing (DAS) data streams, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6189, https://doi.org/10.5194/egusphere-egu23-6189, 2023.

EGU23-6379 | Posters on site | SM2.1

Rotational ground motion recordings in the West Bohemia / Vogtland region for waveform inversion for seismic moment tensors 

Stefanie Donner, Johanna Lehr, Mathias Hoffmann, Frank Krüger, Sebastian Heimann, Rafel Abreu, and Stephanie Durand

In synthetic tests, rotational ground motion recordings proved to be beneficial for the wavefrom inversion for seismic moment tensors. In a next step, we want to verify these findings using real measurements. To do so, we installed two broadband rotational collocated to translational ground motion sensors in the West Bohemia / Vogtland area in summer 2022.

The area is characterised by regular seismic swarm activity, the last one occurring in December 2021. The seismic swarms are known to be connected with crustal flow of mantle fluids. However, the detailed mechanism of this connection is not well understood yet. Full seismic moment tensors, especially their non-double-couple part, will contribute to investigate the connection between swarm activity and fluid flow. So far, a lacking number of moment tensors and difficulties in the reliability of the non-double-couple part hampered the analysis in the study area. Including rotational ground motion recordings to waveform inversion will help to overcome these difficulties.

In seven months, we have recorded 120 events with magnitudes larger than M ≥ 0 in a distance of up to 35 km, thereof 35 around Nový Kostel, the center of the swarm activity. Considering that rotational sensors are about 2-4 times less sensitive than translational sensors (depending on the local phase velocity of the location) this is already a great success. Here, we show details of the sensor installations, first data analysis, and an estimate on the magnitude of completeness from rotational measurements.

How to cite: Donner, S., Lehr, J., Hoffmann, M., Krüger, F., Heimann, S., Abreu, R., and Durand, S.: Rotational ground motion recordings in the West Bohemia / Vogtland region for waveform inversion for seismic moment tensors, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6379, https://doi.org/10.5194/egusphere-egu23-6379, 2023.

EGU23-6422 | ECS | Posters on site | SM2.1

Effect of shallow heterogeneities on wavefield gradients measurements 

Mirko Bracale, Romain Brossier, Helle Pedersen, and Michel Campillo

In recent years, the use of rotational sensors and DAS has become a topic of increasing interest within the seismological community because of their increasing sensitivity and affordability. We analyze the sensitivity of wavefield gradients, in the form of normal strain and rotation, to localized shallow velocity changes in a homogeneous medium.
We performed several numerical simulations, using a suitably modified 3D-SEM code, to observe, in addition to wavefield itself, the normal strain and rotation as a direct output.
We analyzed two case studies in which a velocity anomaly is placed in a homogeneous medium. In the first case the velocity change between the anomaly and the surrounding medium is 10%, in the second case 70%. We analyzed the sensitivity of these new observables in terms of phase shift and amplitude change.
We observe a very local effect of the wavefield gradients, which show larger amplitude near the boundary between the medium and the anomaly, while away from it they behave like the displacement wavefield itself.

How to cite: Bracale, M., Brossier, R., Pedersen, H., and Campillo, M.: Effect of shallow heterogeneities on wavefield gradients measurements, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6422, https://doi.org/10.5194/egusphere-egu23-6422, 2023.

EGU23-6915 | ECS | Posters on site | SM2.1

Modeling and analysis of Distributed Acoustic Sensing (DAS) data in Geothermal environments 

Davide Pecci, Juan Porras, Michele De Solda, Francesco Grigoli, Eusebio Stucchi, and Renato Iannelli

DAS technology is particularly suitable for microseismic monitoring application in geothermal environments. This instrumentation can resist to high temperatures (up to about 100°C or more) higher than the operational temperature of standard acquisition instruments (e.g., geophones), allowing the fiber to be located very close to the reservoir. For this reason, DAS is particularly useful for induced seismicity monitoring of Enhanced Geothermal System (EGS). Being of recent development, this acquisition technology still lacks appropriate modeling and analysis tools able to handle such a large amount of data without losing efficiency. Furthermore, open-access DAS datasets are still a rarity, if compared to other geophysical datasets (e.g., seismological data). Therefore, we aim to generate an open-access synthetic (but realistic) DAS dataset that may help the geophysical community to develop “ad hoc” data analysis methods suitable for this kind of data. In the presented work we make use of the spectral element modeling software 'Salvus', developed by Mondaic, which also allows the simulation of DAS data. In particular, it outputs a strain measurement between all points defined as receivers in the simulation. Using the repositories of DAS data collected at the geothermal test site Frontier Observatory for Research in Geothermal Energy (FORGE) located in Utah (USA), we tried to simulate realistic DAS acquisition conditions of seismic events related to low-magnitude natural seismic activity from the nearby Mineral Mountains and microseismic events related to hydraulic stimulation operations for the generation of an EGS.

In order to obtain realistic synthetic data, we first analyze the spectral properties of real noise waveforms by using the Power Spectral Density (PSD) Analysis. Starting from observed PSDs we model the synthetic noise waveforms using a stochastic approach. Then we add it to the synthetic event traces and compare them with the observed ones. We finally test a semblance-based event detector on a 1-hour continuous waveforms of synthetic data to evaluate the performance of the detector in different operational conditions (e.g., different noise levels and inter-event times).

How to cite: Pecci, D., Porras, J., De Solda, M., Grigoli, F., Stucchi, E., and Iannelli, R.: Modeling and analysis of Distributed Acoustic Sensing (DAS) data in Geothermal environments, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6915, https://doi.org/10.5194/egusphere-egu23-6915, 2023.

EGU23-6998 | ECS | Orals | SM2.1

Exploiting Terrestrial Meshed Optical Data Networks as Environmental Sensing Smart Grids 

Emanuele Virgillito, Stefano Straullu, Rudi Bratovich, Fransisco M. Rodriguez, Hasan Awad, Andrea Castoldi, Roberto Proietti, Andrea D'Amico, Francesco Aquilino, Rosanna Pastorelli, and Vittorio Curri

Optical networks for data transmission have become a pervasive infrastructure in the last years in order to cope with the increasing bandwidth request, thus there is a huge potential to be employed as a wide fiber optic sensing network. In the terrestrial scenario such networks are usually arranged on meshed topologies densely covering large areas of hundreths or thousands of kilometers. On the network's nodes, dedicated hardware is used to routed the data traffic between the connections' endpoints. Such nodes are interconnected by optical fiber links of hundreds of kilometers long, repeated every tenths of kilometers using optical amplifiers.

To fulfill the modern traffic requirements, optical networks are evolving towards multi-service autonomous, flexible, software defined entities based on a centralized intelligence orchestrating the networking functions and communicating with the network elements using standardized interfaces. This trend opens the perspective of using the optical network for evironmental sensing, such as earthquake detection or anthropic activities monitoring. 

Indeed, distributed acoustic sensing (DAS) systems based on Rayleigh scattering have demonstrated that optical fibers are excellent sensors of mechanical stress. However, such systems are expensive and pose some limitations on the maximum reach, so they cannot be deployed extensively. In this context, re-using the already deployed optical data infrastructure to support and integrate dedicated system sensing may be highly beneficial. In this work, we propose an optical data network architecture exposing sensing functionalities with minimum or no additional hardware simply by exploiting the pervasiveness of the telecommunication infrastructure and getting data from the physical quantities already monitored for data transmission purposes. Such architecture on a typical terrestrial optical data network is outlined in figure.

Modern coherent transceivers based on digital signal processing already track the evolution of the transmitted optical signal phase and polarization to recover the transmitted data at the receiver side. As those quantities are strongly affected by external strain, they already contain environmental information. Furthermore, some polarization-based processing can be implemented on cheaper non-coherent transceivers available at each amplifier site as data-service channel, providing several sensing sources.

In addition, further optical devices such as add-drop multiplexer or optical amplifiers typically have several other sensors already embedded (power monitors, temperature sensors) or they can be equipped with some others which can provide environmental data from other physical quantities.

The set of all such environmental data streams produced by the network elements constitutes the streaming telemetry fed to a network controller. A post-process agent may be implemented by exploiting the computational power available in typical network elements to perform local data analysis and reduce the amount of data sent to the sensing controller. By cross-processing the data coming from the network elements, a sensing controller is able to detect and localize events making the network act as a smart grid by continuously monitoring large areas and providing early warning signals.

To support our proposal, in this work we show the results of an experimental activity aimed at detecting and localizing anthropic activities in the city of Turin using a deployed fiber ring.

 

How to cite: Virgillito, E., Straullu, S., Bratovich, R., M. Rodriguez, F., Awad, H., Castoldi, A., Proietti, R., D'Amico, A., Aquilino, F., Pastorelli, R., and Curri, V.: Exploiting Terrestrial Meshed Optical Data Networks as Environmental Sensing Smart Grids, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6998, https://doi.org/10.5194/egusphere-egu23-6998, 2023.

EGU23-7309 | ECS | Orals | SM2.1

Effects of cable geometry and specific noise sources on DAS monitoring potential 

Emanuele Bozzi, Nicola Piana Agostinetti, Alan F. Baird, Carlos Becerril, Biondo Biondi, Andreas Fichtner, Sara Klaasen, Nate Lindsey, Takeshi Nishimura, Patrick Paitz, Junzhu Shen, Arantza Ugalde, Fabian Walter, Siyuan Yuan, Tieyuan Zhu, and Gilberto Saccorotti

The Distributed Acoustic Sensing (DAS) method re-purposes fiber optic cables into a very-dense array of strain/strain-rate sensors, capable of detecting different types of seismic events. However, DAS data are characterized by lower SNRs compared with standard seismic sensors, mainly because of a) strong directivity effects, 2) ground coupling inhomogeneities, and 3) site effects. Hence, beyond the array geometry, specific noise sources may reduce the potential of DAS for seismic monitoring. Previous research has already shown successful case-studies for event detection/location. Nevertheless, a coherent test on the performances of various arrays of different sizes and geometries is still lacking.

In this study, an extensive DAS database is organized for such a goal, including 15 DAS arrays that recorded at least one seismic event (located at a range of distances from the arrays). P wave arrival times are exploited to estimate the epicentral parameters with a Markov Chain Monte Carlo method. Then, to analyze the effects of cable geometry and potential sources of noise/ambiguity on the location uncertainties, a series of synthetic tests are performed, where synthetic traveltimes are modified as follows: a) adding noise with equal variance to all the DAS channels (SYNTH-01), b) adding noise characterized by an increasing variance with the distance from the event (SYNTH-02), c) simulating the mis-pick between P and S phases (SYNTH-03) and d) adding noise with a variance influenced by cable coupling inhomogeneities (SYNTH-04). Results show that the epicentral locations with automatic P wave arrival times have different degrees of uncertainty, given the geometrical relation between the event and the DAS arrays. This behavior is confirmed by the SYNTH-01 test, indicating that specific geometries provide a lower constraint on event location. Moreover, SYNTH-04 shows that simulating cable coupling inhomogeneities primarily reproduces the observed location uncertainties. Finally, some cases are not explained by any of the synthetic tests, stressing the possible presence of more complex noise sources contaminating the signals.

How to cite: Bozzi, E., Piana Agostinetti, N., F. Baird, A., Becerril, C., Biondi, B., Fichtner, A., Klaasen, S., Lindsey, N., Nishimura, T., Paitz, P., Shen, J., Ugalde, A., Walter, F., Yuan, S., Zhu, T., and Saccorotti, G.: Effects of cable geometry and specific noise sources on DAS monitoring potential, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7309, https://doi.org/10.5194/egusphere-egu23-7309, 2023.

EGU23-7563 | ECS | Posters on site | SM2.1

TwistPy: An open-source Python toolbox for wavefield inertial sensing techniques 

David Sollberger, Sebastian Heimann, Felix Bernauer, Eva P. S. Eibl, Stefanie Donner, Céline Hadziioannou, Heiner Igel, Shihao Yuan, and Joachim Wassermann

In the past decade, significant progress has been made in the acquisition and processing of seismic wavefield gradient data (e.g., recordings of ground strain and rotation). When combined with conventional multicomponent seismic data, wavefield gradients enable the estimation of local wavefield properties (e.g., the local wave speed, the propagation direction, and the wave type) and the reconstruction of spatially under-sampled seismic wavefields. However, the seismological community has yet to embrace wavefield gradient data as a new observable.

We present TwistPy (Toolbox for Wavefield Inertial Sensing Techniques), an open-source software package for seismic data processing written in Python. It includes routines for single-station polarization analysis and filtering, as well as array processing tools. A special focus lies on innovative techniques to process spatial wavefield gradient data and, in particular, rotational seismic data obtained from dedicated rotational seismometers or small-aperture arrays of three-component sensors. Routines currently included in the package comprise polarization analysis and filtering in both the time domain and the time-frequency domain (for three-component and six-component data), dynamic tilt corrections, and beamforming (Bartlett, Capon, and MUSIC beamformers).  

With TwistPy, we attempt to lower the barrier of entry for the seismological community to use state-of-the art multicomponent and wavefield gradient analysis techniques by providing a user-friendly software interface.

Extensive documentation of the software and examples in the form of Jupyter notebooks can be found at https://twistpy.org.

How to cite: Sollberger, D., Heimann, S., Bernauer, F., Eibl, E. P. S., Donner, S., Hadziioannou, C., Igel, H., Yuan, S., and Wassermann, J.: TwistPy: An open-source Python toolbox for wavefield inertial sensing techniques, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7563, https://doi.org/10.5194/egusphere-egu23-7563, 2023.

EGU23-8327 | Posters on site | SM2.1

Fibre-optic dynamic strain borehole sensing at Etna volcano 

Philippe Jousset, Gilda Currenti, Rosalba Napoli, Mario Pulvirenti, Daniele Pelligrino, Christian Cunow, Graziano Larocca, Alessandro Bonaccorso, Giuseppe Leto, and Charlotte Krawczyk

Volcano monitoring has been experiencing significant improvements in recent years, yet eruption forecasting and scenarios have still lack of understanding, due to the poor observations in low amplitude events and hindered by surface external noise of similar amplitudes. Volcanic events have been shown to be accurately recorded with fiber optic techniques at the surface. In this study, we present preliminary results of fibre optic cable deployed in a new 200 m deep borehole on the southern flank of Etna at about 6 km away from the summit crater. This borehole has been designed primarily for the future deployment of a new strain sensor type. We benefited from the drilling of this new borehole to deploy a single-mode fibre optic cable. We connected an interrogator and recorded dynamic strain rate during several periods: first, in 2020 for several days during the completion of the borehole and the final stage of the drilling; second, in 2021 for several weeks during an active volcanic period; and in December 2022 during a quiet activity period of several months. We present a selection of records of noise while drilling, local volcano-tectonic earthquakes and volcanic events and tremor that occurred during those periods. These examples show the benefit of deploying a fibre in a borehole far from the active area and demonstrate the great variety of signals fibre optic can record is such configuration.

How to cite: Jousset, P., Currenti, G., Napoli, R., Pulvirenti, M., Pelligrino, D., Cunow, C., Larocca, G., Bonaccorso, A., Leto, G., and Krawczyk, C.: Fibre-optic dynamic strain borehole sensing at Etna volcano, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8327, https://doi.org/10.5194/egusphere-egu23-8327, 2023.

EGU23-8569 | Posters on site | SM2.1

Monitoring a commercially operating submarine telecom cable network in the Guadeloupe archipelago (Lesser Antilles) using Brillouin Optical Time Domain Reflectometry (BOTDR) 

Marc-Andre Gutscher, Lionel Quetel, Giuseppe Cappelli, Jean-Gabriel Quillin, Christophe Nativelle, Jean-Frederic Lebrun, and Melody Philippon

Submarine telecom cables criss-cross the oceans, connecting islands to continents and providing internet, financial and media services to consumers all around the world. Laser reflectometry as well as other optical techniques can potentially transform the optical fibers in these cables into sensors which can detect vibrations and ground motion from earthquakes, ocean waves, currents as well as permanent deformation of the seafloor. The goal of the ERC (European Research Council) funded project - FOCUS is to apply laser reflectometry on submarine fiber optic cables to detect deformation at the seafloor using BOTDR (Brillouin Optical Time Domain Reflectometry). This technique is commonly used monitoring large-scale engineering infrastructures (e.g. - bridges, dams, pipelines, etc.) and can measure very small strains (<< 1 mm/m) at very large distances (10 - 200 km), but until now has never been used to study movements at the seafloor.

 

Within the framework of the FOCUS project, and in collaboration with the “Conseil Regional” of Guadeloupe, in 2022 we began long-term monitoring of a network of submarine telecom cables that link the islands of the Guadeloupe archipelago. These cables connect the larger island of Basse Terre and Grande Terre to the smaller southern islands of Les Saintes, Marie Galante and La Desirade, with segment lengths ranging from 30 to 70 km. This network was deployed recently (in 2019) and is the property of the Conseil Regional of Guadeloupe, operated with the assistance of Orange. All cables contain twelve fiber pairs, of which three pairs are in use by mobile phone operators and thus unused fibers were available for this scientific monitoring project. In June 2022, we established BOTDR baselines on 8 optical fiber segments, in several cases in both directions. In December 2022, we repeated the measurements of the same fiber segments, allowing us to detect any strain along the cable over this period.

 

Here, we report that using the BOTDR technique, we detect significant strain signals  (50 micro-strain and more) in several locations along the cable network. These signals, which can be positive (elongation) or negative (shortening) occur typically in areas of steep seafloor slopes or in submarine valleys/canyons. Our tentative interpretation is that stretching and shortening of the cable (representing about 1 cm over a few hundred meters) is occurring, most likely due to sea-bottom currents. These currents may be related to the late summer/early autumn hurricane season, with the passage of tropical storm Fiona in Sept. 2022 dropping heavy rains, causing torrential floods and debris flows in some of the larger rivers with possible impacts further offshore. A longer time-series and more detailed analysis are necessary to test this preliminary hypothesis.

How to cite: Gutscher, M.-A., Quetel, L., Cappelli, G., Quillin, J.-G., Nativelle, C., Lebrun, J.-F., and Philippon, M.: Monitoring a commercially operating submarine telecom cable network in the Guadeloupe archipelago (Lesser Antilles) using Brillouin Optical Time Domain Reflectometry (BOTDR), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8569, https://doi.org/10.5194/egusphere-egu23-8569, 2023.

EGU23-8851 | ECS | Orals | SM2.1

Using Rotational Motions to understand material damage in Civil Engineering structure 

Anjali Dhabu, Felix Bernauer, Chun-Man Liao, Celine Hadziioannou, Heiner Igel, and Ernst Niederleithinger

The increasing evidence of rotational motions due to earthquakes is now motivating civil engineers to investigate the effects of rotational ground motions on structures. With the advancement in instrumentation techniques, rotational sensors have been developed in the past few years, which can measure three components of rotational waves in addition to the translational waves. Conventionally, buildings are designed to withstand horizontal and vertical translational ground motions to minimize the damage to human life and financial losses during an earthquake. Damage to the structure is identified at two levels; (i) structural and (ii) material. The structural damage in reinforced concrete buildings is visible in the form of cracks and spalling concrete, which reduces the overall load-carrying capacity of the building. The damage at the material level is not visible to the human eye. This damage can be identified using coda wave interferometry techniques. In this method, a high cross-correlation between the coda of two waves passing a point on different days of experiment indicates a negligible change in the shear wave velocity of the material. In comparison, a lower cross-correlation signifies considerable change in the material properties.    

In order to understand how rotational motions affect reinforced concrete structures and how these can be simulated, the present work makes a novel attempt to use the newly developed rotation measuring sensors, BlueSeis 3A and IMU50, to understand the damage in a model concrete bridge structure (BLEIB). We employ advanced sensors in addition to conventional broadband and ultrasonic sensors on the 24m long two-span continuous reinforced concrete bridge equipped with various non-destructive sensing techniques and subjected to a variable pre-tension force of up to 450kN and various static loads. As an initial analysis, we first identify the bridge's first three fundamental frequencies and mode shapes from both recorded translational and rotational data. The analysis shows that the same fundamental frequencies are obtained from the recorded translational and rotational data. However, we expect to see a difference in the mode shapes. Theoretically, rotations are maximum at the bridge support and minimum at the centre of the bridge span. This behaviour is the reverse of what we observe from translational motions, where maximum translations are observed at the centre of the span while minimum at the supports. As the study plans to simulate rotational motions for reinforced concrete structures, a finite element model of the prototype bridge is also developed, and the fundamental frequencies and mode shapes of the model are validated with those obtained from the recorded data. This work shall be extended to applying coda wave interferometry to the rotational data recorded on the bridge to understanding the change observed in material properties when the bridge is subjected to active and passive forces.

How to cite: Dhabu, A., Bernauer, F., Liao, C.-M., Hadziioannou, C., Igel, H., and Niederleithinger, E.: Using Rotational Motions to understand material damage in Civil Engineering structure, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8851, https://doi.org/10.5194/egusphere-egu23-8851, 2023.

EGU23-9089 | ECS | Orals | SM2.1

Detecting seismo-volcanic events based on inter-channel coherency of a DAS cable 

Julius Grimm, Piero Poli, and Philippe Jousset

Distributed Acoustic Sensing (DAS) has been successfully employed to monitor volcanic seismicity and to infer volcanic subsurface structures. Here, we analyse data recorded in September 2018 at Mount Etna by the 9N seismic network. The multi-instrument network includes a 1.3 km long fibre-optic cable that was buried 2-2.5 km away from the main craters. Additionally, 15 geophones were installed along the trajectory of the DAS cable, allowing for a comparison of strain-rate and ground velocity data.
During the acquisition period, tiny seismic events, likely caused by fluid movement and degassing, are visible with inter-event times in the range of 1 min. Volcanic explosions and volcano-tectonic earthquakes also occur frequently. We detect events over all frequency ranges by calculating the coherence matrix for very short time windows (stacking 15 windows of 5 seconds length). An eigendecomposition of the coherence matrices allows to extract the first eigenvectors, corresponding to the dominant source in the time window. The principal eigenvectors can be clustered to find groups of events with similar source properties. We also use the principal eigenvector of already known events as a matched filter to scan the whole dataset. The results of the DAS cable are compared to the observations of the geophone array. While largely obtaining similar findings, the DAS cable seems to better capture high-frequency features of certain events. We also explore the effects of stacking and downsampling of the DAS data prior to detection, which influences both resolution and computational efficiency of the algorithm.

How to cite: Grimm, J., Poli, P., and Jousset, P.: Detecting seismo-volcanic events based on inter-channel coherency of a DAS cable, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9089, https://doi.org/10.5194/egusphere-egu23-9089, 2023.

EGU23-9312 | Orals | SM2.1

Six-component wave type fingerprinting and filtering 

David Sollberger, Nicholas Bradley, Pascal Edme, and Johan O. A. Robertsson

We present a technique to automatically classify the wave type of seismic phases that are recorded on a single six-component recording station (measuring both three components of translational and rotational ground motion) at the earth's surface. We make use of the fact that each wave type leaves a unique 'fingerprint' in the six-component motion of the sensor. This fingerprint can be extracted by performing an eigenanalysis of the data covariance matrix, similar to conventional three-component polarization analysis. To assign a wave type to the fingerprint extracted from the data, we compare it to analytically derived six-component polarization models that are valid for pure-state plane wave arrivals. For efficient classification, we make use of the supervised machine learning method of support vector machines that is trained using data-independent, analytically-derived six-component polarization models. This enables the rapid classification of seismic phases in a fully automated fashion, even for large data volumes, such as encountered in land-seismic exploration or ambient noise seismology. Once the wave-type is known, additional wave parameters (velocity, directionality, and ellipticity) can be directly extracted from the six-component polarization states without the need to resort to expensive optimization algorithms.

We illustrate the benefits of our approach on various real and synthetic data examples for applications such as automated phase picking, aliased ground-roll suppression in land-seismic exploration, and the rapid close-to real time extraction of surface wave dispersion curves from single-station recordings of ambient noise. Additionally, we argue that an initial step of wave type classification is necessary in order to successfully apply the common technique of extracting phase velocities from combined measurements of rotational and translational motion.

How to cite: Sollberger, D., Bradley, N., Edme, P., and Robertsson, J. O. A.: Six-component wave type fingerprinting and filtering, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9312, https://doi.org/10.5194/egusphere-egu23-9312, 2023.

EGU23-9314 | ECS | Orals | SM2.1

Using Distributed Fiber-optic Sensing for Tracking Caprock Fault Activation Processes 

Verónica Rodríguez Tribaldos, Chet Hopp, Florian Soom, Yves Guglielmi, Paul Cook, Tanner Shadoan, Jonathan Ajo-Franklin, Michelle Robertson, Todd Wood, and Jens Birkholzer

Identifying and monitoring the reactivation of faults and opening of fractures affecting low permeability, sealing formations in natural underground storage complexes such as Carbon Capture and Storage projects and Nuclear Waste repositories is essential to ensure storage integrity and containment. Although passive seismic monitoring can be effective for detecting induced failure, stress accumulation and fault reactivation can occur aseismically in clay-rich formations, preventing early failure to be recognized. Here, we investigate the potential of applying strain monitoring with fiber-optics sensing technologies to assess in-situ changing stress conditions at high spatial and temporal resolution.

We present results of fiber-optic sensing monitoring during the FS-B experiment, a controlled activation of a fault zone affecting the Opalinus Clay Formation in the Mont Terri underground Laboratory (Switzerland). Six constant flowrate water injections induced the hydraulic opening of the fault. A hydraulic connection between the injector and a monitoring borehole occurred, developing a flow path sub-parallel to the fault strike. A 2 km long fiber-optic cable looped through 10 monitoring boreholes surrounding and crossing the fault zone was used for distributed acoustic and strain sensing (DAS and DSS) before, during and after injection. Continuous low-frequency (< 1 Hz) DAS data reveals mechanical strain associated with fault reactivation. Increasing extensional strain is recorded near the point of injection and near the newly formed hydraulic flow path, reaching a value of ~150 μɛ. Post-activation residual strain of ~60 μɛ suggests irreversible fault zone deformation. Smaller strain changes are recorded above and below the high pressure flow path, suggesting a mechanically disturbed zone larger than the leakage zone. Low-frequency DAS data are consistent with co-located DSS strain data, local, 3D displacement measurements of fault movements and P-wave velocity anomalies derived from Continuous Active Source Seismic Monitoring (CASSM). Our results are promising and demonstrate the potential of fiber-optic sensing as a powerful tool for monitoring spatio-temporal evolution of fault reactivation processes and leakage in clay formations induced by fluid pressurization.

How to cite: Rodríguez Tribaldos, V., Hopp, C., Soom, F., Guglielmi, Y., Cook, P., Shadoan, T., Ajo-Franklin, J., Robertson, M., Wood, T., and Birkholzer, J.: Using Distributed Fiber-optic Sensing for Tracking Caprock Fault Activation Processes, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9314, https://doi.org/10.5194/egusphere-egu23-9314, 2023.

EGU23-9629 | ECS | Posters on site | SM2.1

Monitoring material properties of civil engineering structures with 6C point measurements 

Felix Bernauer, Shihao Yuan, Joachim Wassermann, Heiner Igel, Celine Hadziioannou, Frederic Guattari, Chun-Man Liao, Ernst Niederleitinger, and Eva P. S. Eibl

Observing motion within a building in six degrees of freedom (three components of translational motion plus three components of rotational motion) opens completely new approaches to structural health monitoring. Inspired by inertial navigation, we can monitor the absolute motion of a building or parts of it without the need for an external reference. Rotational motion sensors can directly measure harmful torsional modes of a building, which has always been challenging and prone to errors when using translation sensors only. Currently, we are developing methodologies including rotational motion observations for monitoring of material parameters in order to locate and characterize structural damage. Within the framework of the GIOTTO project (funded by the German Federal Ministry for Education and Research, BMBF) we explore these approaches.

Here, we introduce a newly developed 6C sensor network for structural health monitoring. It consists of 14 inertial measurement units (IMU50 from exail, former iXblue, France) that were adapted to the needs of seismology and structural health monitoring. We performed experiments at the BLEIB test structure of the Bundesanstalt für Materialforschung und -prüfung (BAM), a 24 m long concrete beam serving as a large scale bridge model. We present results on detecting changes in material properties (seismic wave speed) of the beam with varying pre-stress and load, as derived from a novel approach by comparing amplitudes of translational to rotational motions at a single measurement point. We compare our findings to results obtained with coda wave interferometry using rotational as well as translational motions.

How to cite: Bernauer, F., Yuan, S., Wassermann, J., Igel, H., Hadziioannou, C., Guattari, F., Liao, C.-M., Niederleitinger, E., and Eibl, E. P. S.: Monitoring material properties of civil engineering structures with 6C point measurements, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9629, https://doi.org/10.5194/egusphere-egu23-9629, 2023.

EGU23-9641 | Posters on site | SM2.1

Loops of slack in dark fiber and their effect on interferometric analysis of ambient noise – symptoms, consequences and remedies 

Christopher Wollin, Leila Ehsaninezhad, Johannes Hart, Martin Lipus, and Charlotte Krawczyk

Seismic microzonation and ambient noise tomography via Distributed Acoustic Sensing (DAS) may contribute to the seismic hazard assessment and the exploration or monitoring of utilizable and utilised subsurface volumes at favorable costs. However, numerous technical aspects remain under investigation to further maturate this innovative seismological approach – particularly when applied to dark telecommunication fibers. For instance unknown coupling of the fiber to the ground or presence of loops of slack fiber may disturb the regular measuring of the stringed virtual sensors.

 

In this study, we investigate how loops of slack fiber affect the results of passive ambient tomography, a particularly appealing exploration approach due to its low footprint. We present results obtained with DAS recordings on purposefully installed as well as dark telecommunication optic fiber. Sledgehammer blows were recorded on an optic fiber laid out in an urban heating tunnel before and after introducing several loops of slack. The loops coiled up fractions and multiples of the utilized gauge length and were spaced in sufficient distance to independently analyze the surrounding wavefield. Discontinuous wavefronts can be observed once the coiled fiber exceeds the gauge length. Similar observations were made on the virtual shot gathers calculated along a 4.5 km long segment of dark fiber along a major road in the city of Berlin, Germany. We show how the loops of slack affect the further processing with respect to ambient noise tomography. On average, the removal of virtual sensors identified to be located in coiled fiber reduces the shear-wave velocities in the resulting model.

 

We conclude that the careful removal of virtual sensors within loops of slack is a mandatory processing step towards ambient noise tomography with linear DAS arrays. However, the calculation of virtual shot gathers can help to reveal the affected fiber segments.

How to cite: Wollin, C., Ehsaninezhad, L., Hart, J., Lipus, M., and Krawczyk, C.: Loops of slack in dark fiber and their effect on interferometric analysis of ambient noise – symptoms, consequences and remedies, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9641, https://doi.org/10.5194/egusphere-egu23-9641, 2023.

EGU23-10767 | ECS | Posters on site | SM2.1

Exploring multiscale nonlinear NDTs for damage detection in concrete structures 

Marco Dominguez-Bureos, Celine Hadziioannou, Niklas Epple, Camila Sanchez Trujillo, and Ernst Niederleithinger

It has been shown that non-destructive tests (NDTs) based on nonlinear wave propagation are more sensitive to detecting very small damages in concrete structures than linear techniques. With the aim of exploring the nonlinear effects in civil structures as a damage indicator, we perform a 1-day multiscale vibration monitoring of a test bridge equipped with a pretension system.

We used the pretension system to subject the specimen to eight compression states in its longitudinal direction (400kN at the highest, and 280kN at the lowest). At every compression state, we struck the structure in the vertical direction three times at two locations on the bridge with an impulse source. Throughout the whole experiment, we recorded seismic ambient noise at different frequency bands with a 14-IMU50-sensor array to measure the acceleration and rotation rate, a 14-geophone array with a 4.5 Hz natural frequency, a DAS system, and 4 pairs of ultrasound transducers; the internal temperature of the concrete was also recorded.

At the structural scale (from 1 to 40 Hz) we were able to observe different responses of the structure to pre-tension changes, depending on where the measurement took place in relation to the vertical support pillars by estimating relative velocity changes using the Coda Wave Interferometry stretching processing technique.

At the material scale (ultrasound regime) we can observe temperature-dependent slow dynamics features related to changes in the seismic velocity of the concrete as a consequence of vertical strikes, and its recovery process that returns its physical properties to a steady state after the action of the impulse source.

With this work, we work towards the development of new NDTs that are increasingly sensitive to small cracks and imperfections using conventional and non-conventional seismic instruments to measure linear and nonlinear wave propagation.

How to cite: Dominguez-Bureos, M., Hadziioannou, C., Epple, N., Sanchez Trujillo, C., and Niederleithinger, E.: Exploring multiscale nonlinear NDTs for damage detection in concrete structures, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10767, https://doi.org/10.5194/egusphere-egu23-10767, 2023.

EGU23-11782 | ECS | Posters on site | SM2.1

A workflow to generate DAS based earthquake catalog, applied to an offshore telecommunication cable in central Chile 

Marie Baillet, Alister Trabattoni, Martijn Van Den Ende, Clara Vernet, and Diane Rivet

Fiber-optic Distributed Acoustic Sensing (DAS) is of critical value for the expansion of seismological networks, particularly in regions that are hard to instrument. The work presented here is part of the 5-year ERC ABYSS project, which aims at building a permanent seafloor observatory to increase our ability to capture low magnitude seismic signals from the subduction fault zone in the DAS data recorded by offshore telecommunication cables along the central coast of Chile.

In preparation for this project, a first experiment named POST was conducted from October to December 2021 on a submarine fiber-optic cable connecting the city of Concón to La Serena. DAS data were recorded continuously for 38 days over a distance of 150 km from Concón, constituting more than 36700 virtual sensors sampling at 125 Hz. This experiment provided an opportunity to anticipate what will be recorded over the next 5 years of the project, and to allow us to develop routines that will be applied later for real-time data processing.

As a first step, we developed an automated routine for generating a preliminary earthquake catalog, comprising various conventional signal processing steps, including data denoising, change-point detection, and separating seismic events from transient instrumental noise making use of the two-dimensional character of the DAS data. Over a span of 38 days (worth 72 TB of data), our pipeline detected more than 900 local, regional, and teleseismic events with local magnitudes down to ML < 2 (based on the Centro Sismológico Nacional (CSN) public catalog). The size of our catalog, enriched with numerous off-shore events, is a significant improvement over the current CSN catalog, which may aid future studies into the Chilean margin subduction zone seismicity.

How to cite: Baillet, M., Trabattoni, A., Van Den Ende, M., Vernet, C., and Rivet, D.: A workflow to generate DAS based earthquake catalog, applied to an offshore telecommunication cable in central Chile, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11782, https://doi.org/10.5194/egusphere-egu23-11782, 2023.

EGU23-11842 | Orals | SM2.1

Using path-integrated strain in Distributed Acoustic Sensing 

Alister Trabattoni, Francesco Biagioli, Claudio Strumia, Gaetano Festa, Martijn van den Ende, Diane Rivet, Anthony Sladen, Jean-Paul Ampuero, Jean-Philippe Metexian, and Éléonore Stutzmann

Distributed Acoustic Sensing (DAS) is becoming a well-established technology in seismology. For historical and practical reasons, DAS manufacturers usually provide instruments that natively record strain (rate) as the principal measurement. While at first glance strain recordings appear similar to particle motion (displacement, velocity, acceleration) waveforms, not all of the seismological tools developed over the past century (e.g., magnitude estimation, seismic beamforming, etc.) can be readily applied to strain data. Notably, the directional sensitivity of DAS differs from conventional particle motion sensors, and DAS experiences an increased sensitivity to slow waves, often composed of highly scattered waves that are challenging to analyze. To address these issues, several strategies have been already proposed to convert strain rate measurements to particle velocity.

Based on a previously proposed mathematical formalism, we stress some fundamental differences between path-integrated strain and conventional displacement measurements. DAS inherently records arc length variation of the cable which is a relative motion measurement along a curvilinear path. We show that if the geometry of the DAS deployment is adapted to the wavefield of interest, path-integrated strain can be used to closely approximate the displacement wavefield without the need of additional instruments. We validate this theoretical result using collocated seismometers, discuss the limitations of this approach, and show two benefits: enhancing direct P-wave arrivals and simplifying the magnitude estimation of seismic events. While using path integrated strain is in some aspects more challenging, it achieves flat (hence lower) noise levels both in frequency and wavenumber. It also provides better sensitivity to high velocity phases, and permits the direct application of conventional seismological tools that are less effective when applied to the original strain data.

How to cite: Trabattoni, A., Biagioli, F., Strumia, C., Festa, G., van den Ende, M., Rivet, D., Sladen, A., Ampuero, J.-P., Metexian, J.-P., and Stutzmann, É.: Using path-integrated strain in Distributed Acoustic Sensing, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11842, https://doi.org/10.5194/egusphere-egu23-11842, 2023.

EGU23-12213 | ECS | Posters on site | SM2.1

Near-surface seismic characterisation of a railway embankment slope using fibre-optic distributed acoustic sensing 

Giuseppe Maggio, Andrew Trafford, and Shane Donohue

The behaviour of geological slopes during seasonal weather patterns represents one of the challenges for assessing the geotechnical state of health of the ageing infrastructures. In the presence of man-made soil infrastructure slopes, rainfall and prolonged dry periods can cause cycles of swelling and shrinking of the ground that could potentially compromise their structural integrity. Recent research has found that time-lapse velocity monitoring, has the potential to provide information on climate-related deterioration of geotechnical infrastructure. Variations of the ground conditions could manifest as changes in seismic velocity, detectable through the seasons and after extreme weather events.

In this work, we perform seismic imaging and velocity-monitoring of a critical railway embankment in the United Kingdom using fibre optic distributed sensing (DAS). The study area is a 6 m tall, and 350 m long embankment slope built more than 100 years ago in the outskirts of London (Surrey). The railway is currently utilised mostly by commuter trains. Since August 2022, a passive DAS dataset rich in train signals has been acquired. data acquisition will continue until July 2023. Furthermore, periodic active surveys have been conducted along the slope.

Firstly, to validate the seismic response of the fibre (i.e., maximum usable frequencies based on the gauge length), we calculate and compare surface wave dispersion curves derived from both DAS and geophones using passive ambient noise, train signals and active sledgehammer shots. As a result, we obtain consistent and comparable dispersion curves ranging from ~200 m/s at 10 Hz to ~140m/s at 40 Hz. 

Secondly, we invert, using global search algorithms, DAS-derived dispersion curves for 1D depth-velocity models to identify and clarify the trend of the near-surface (top 10 m) seismic structures. 

Thirdly, we apply seismic interferometry and moving window cross-spectral techniques to measure changes in seismic velocity at the embankment using the 6-month passive DAS data acquired so far. 

The ultimate goal of this project is to develop a geophysical tool diagnostic of geotechnical deterioration of critical infrastructures by linking together DAS-based seismic observations, temporal seismic velocity changes, weather data and laboratory-based soil sample tests.

How to cite: Maggio, G., Trafford, A., and Donohue, S.: Near-surface seismic characterisation of a railway embankment slope using fibre-optic distributed acoustic sensing, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12213, https://doi.org/10.5194/egusphere-egu23-12213, 2023.

EGU23-12740 | ECS | Orals | SM2.1

Coherence-based Amplification of Rayleigh Waves from Urban Anthropogenic Noise recorded with Distributed Acoustic Sensing 

Leila Ehsaninezhad, Christopher Wollin, Benjamin Schwarz, and Charlotte Krawczyk

At a local scale, e.g. in urban settlements, seismic subsurface characterization requires implementing experiments at high spatial resolution. Distributed acoustic sensing (DAS) provides the opportunity of using pre-existing fiber optic cables as dense receiver arrays, thus potentially reducing the effort for active seismic surveying in urban areas. Due to their small footprint, passive experiments appear particularly appealing. However, extracting coherent signals in an urban environment, i.e. in the presence of anthropogenic activity in the receivers' vicinity, remains a challenge.

 

In this study, we present results from combining the well known technique of Multichannel Analysis of Surface Waves (MASW) with the coherency-based enhancement of wavefields. The investigation is based on a DAS dataset acquired along a major road in Berlin, Germany. We analyse a 4.5 km long straight subsegment of a dark fiber that was sampled at 8 m intervals with 1000 Hz over a period of 15 days. After temporal decimation and the interferometric analysis, clear causal and a-causal branches of Rayleigh-surface waves emerge in the virtual shot gathers.

 

In the further processing, we employ coherence-based enhancement of wavefields to amplify the Signal to Noise Ratio of the virtual shot gathers. Compared to the traditional workflow of ambient-noise tomography the modified one yields improved dispersion curves particularly in the low-frequency part of the signal. This leads to an increased investigation depth along with lower uncertainties in the inversion result. The final velocity model reaches depths down to 300 m. We show that the application of coherence-based enhancement of the virtual shot gathers in the MASW-workflow may significantly relax the necessity of collecting long baselines for passive tomography in urban environments.

How to cite: Ehsaninezhad, L., Wollin, C., Schwarz, B., and Krawczyk, C.: Coherence-based Amplification of Rayleigh Waves from Urban Anthropogenic Noise recorded with Distributed Acoustic Sensing, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12740, https://doi.org/10.5194/egusphere-egu23-12740, 2023.

EGU23-13600 | Orals | SM2.1

Long-awaited and delayed Transportable Highest grade of Fiber Optic Gyroscope for Seismology 

Frédéric Guattari, Guillaume Lenogue, Kevin Gautier, Arnaud Frenois, and André Couderette

First announced at EGU2021, and said to be “released soon”, the 1C rotation seismometer which complements the blueSeis product line on the high performance segment, will be finally disclosed at EGU2023.

2019 and 2020 results have been shared about large mockup of giant Fiber-Optic Gyroscope from iXblue, having diameter as large as 1.2 meters, and the development road to reach an industrial product had been drawn. But several critical additional issues raised on the track.

Keeping in mind all the requirement of the instrument, the need for a transportable, and easily deployable instrument, the calibration capability, the possibility to push the performance pilling up the sensors, and the need for an optional orthogonal structure, we finally come to an instrumental solution with high versatility at expected performances.

The full development story will be shared, and the tests results of first production units of blueSeis-1C will be disclosed. Explanation about the various way to use it will be offered too.

Perspectives and applications using this long-awaited sensor will be presented, from ocean-bottom system tilt denoising to improved inversion of the seismic source.

How to cite: Guattari, F., Lenogue, G., Gautier, K., Frenois, A., and Couderette, A.: Long-awaited and delayed Transportable Highest grade of Fiber Optic Gyroscope for Seismology, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13600, https://doi.org/10.5194/egusphere-egu23-13600, 2023.

EGU23-13803 | ECS | Orals | SM2.1

Magnitude Estimation and Ground Motion Prediction to Harness Fiber Optic Distributed Acoustic Sensing for Earthquake Early Warning 

Itzhak Lior, Diane Rivet, Jean-Paul Ampuero, Anthony Sladen, Sergio Barrientos, Rodrigo Sánchez-Olavarría, German Alberto Villarroel Opazo, and Jose Antonio Bustamante Prado

Earthquake Early Warning (EEW) systems provide seconds to tens of seconds of warning time before potentially-damaging ground motions are felt. For optimal warning times, seismic sensors should be installed as close as possible to expected earthquake sources. However, while the most hazardous earthquakes on Earth occur underwater, most seismological stations are located on-land; precious seconds may go by before these earthquakes are detected. In this work, we harness available optical fiber infrastructure for EEW using the novel approach of Distributed Acoustic Sensing (DAS). DAS strain measurements of earthquakes from different regions are converted to ground motions using a real-time slant-stack approach, magnitudes are estimated using a theoretical earthquake source model, and ground shaking intensities are predicted via ground motion prediction equations. The results demonstrate the potential of DAS-based EEW and the significant time-gains that can be achieved compared to the use of standard sensors, in particular for offshore earthquakes.

How to cite: Lior, I., Rivet, D., Ampuero, J.-P., Sladen, A., Barrientos, S., Sánchez-Olavarría, R., Villarroel Opazo, G. A., and Bustamante Prado, J. A.: Magnitude Estimation and Ground Motion Prediction to Harness Fiber Optic Distributed Acoustic Sensing for Earthquake Early Warning, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13803, https://doi.org/10.5194/egusphere-egu23-13803, 2023.

EGU23-14093 | Posters on site | SM2.1

Six-component records of local seismicity in the Long Valley Caldera, Californica, US 

Johana Brokesova and Jiri Malek

Long Valley Caldera in the eastern part of California is a depression 32 km long and 18 km width, which was formed during a supervolcano eruption 760 000 years ago.  Weak volcanic activity manifested by hot springs, CO2 emmanations and earthhquake swarms in the caldera and neighboring Mammoth Mountain volcanic complex has been continuing until present. The seismicity in the area is the subject of intensive study. In 2016 - 2017 the monitoring system was supplemented by small-aperture array consisting of three short-period Rotaphone-D seismographs. The instruments were deployed in vaults few hundred meters apart at depts from 3.2 to 2.2 m. They are new short-period seismographs measuring three translational and three rotational components. The array enabled new methods of microearthquakes investigation. The noise from surface sources (mainly traffic along nearby highway) can be suppressed significantly by non-linear summing of redundant translational data from each Rotaphone. This enabled detection of very weak microearthquakes in the vicinity of the array with good signal-to-noise ratio. The true azimuth and phase velocity along surface are determined by two methods:  the zero-crossing point beamforming and rotation-to-translation relations. Based on these quantities, location of microearthquakes was performed and it was compared to the locations from the USGS catalogue of local earthquakes.

The six-component records in the Long Valley Caldera are extremely complex. Strong phases between P- and S-wave onsets and namely within the S-wave group are visible in most seismograms. They probably originated as reflection and refraction waves at distinctive interfaces beneath the sediment filling of the caldera. Six-component records enabled analysis of individual wavetypes in the seismograms. The seismic array was reinstalled in the summer 2021 with new data-acquisition system with bigger dynamic range (32 bits A/D converter). We expect even more sensitive measurements from this new observation. 

How to cite: Brokesova, J. and Malek, J.: Six-component records of local seismicity in the Long Valley Caldera, Californica, US, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14093, https://doi.org/10.5194/egusphere-egu23-14093, 2023.

EGU23-14444 | ECS | Orals | SM2.1

Modelling of DAS cable and ground coupling response using Discrete Particle Schemes 

Nicolas Luca Celli, Christopher J. Bean, Gareth O'Brien, and Nima Nooshiri

Since its first applications in the past decade, the use of fiber optic cables as ground motion sensors has become a central topic for seismologists, with successful applications of Distributed Acoustic Sensing (DAS) in various key fields such as seismic monitoring, structural imaging and source characterisation.

The instrument response of DAS cables however is largely unknown. Instrument response is a combination of instrument design, local site effects and ground coupling, and for DAS, the latter ones are believed to have a strong, spatially variable, but yet largely unquantified effect. This limits the application of a large number of staple seismological techniques (e.g. earthquake magnitude estimation, waveform tomography) that can require accurate knowledge of a signal’s amplitude and frequency content.

Here we present a method for accurately simulating a DAS cable and its response. The scheme is based on molecular dynamic-like particle-based numerical modelling, allowing the investigation of the effect of varying DAS-ground coupling scenarios. At first, we compute the full strain field directly, for each pair of neighbouring particles in the model. We then define a virtual DAS cable, embedded within the model and formed by a single string of interconnected particles. This allows us to control all aspects of the cable-ground coupling and their properties at an effective granular level through changing the bond strengths and bond types (e.g. nonlinearity) for both the cable and the surrounding medium. Arbitrary cable geometries and heterogeneous materials can be accommodated at the desired scale of investigation.

We observe that at the meter scale, realistic DAS materials, cable-ground coupling and the presence of unconsolidated trench materials around it dramatically affect wave propagation, each change affecting the synthetic DAS record, with differences exceeding at times the magnitude of the recorded signal. These differences show that cable coupling and local site effects have to be considered both when designing a DAS deployment and analysing its data when either true or along-cable relative amplitudes are considered.

How to cite: Celli, N. L., Bean, C. J., O'Brien, G., and Nooshiri, N.: Modelling of DAS cable and ground coupling response using Discrete Particle Schemes, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14444, https://doi.org/10.5194/egusphere-egu23-14444, 2023.

EGU23-15048 | ECS | Posters on site | SM2.1

On Seismic Wave Equation Gradiometric Inversion for Density 

Marthe Faber and Andrew Curtis

It is of interest for environmental and resource applications to better characterise dynamic processes and properties of the near-surface critical zone of the solid Earth. Seismic wavefield gradiometry refers to a class of imaging techniques that estimate properties of the subsurface by calculating temporal and spatial gradients of incoming wavefields using dense array measurements, usually recorded at the Earth’s surface. One such method called wave equation inversion (WEI) has been shown to require only a few minutes of ambient seismic noise recordings to produce phase velocity maps, and shows promise for rapid field deployment.

Previous applications of WEI are based on the assumption that the 2D scalar Helmholtz wave equation adequately describes the dynamics of recorded wavefields. This approximation is severe for seismic waves because the Helmholtz equation fails to describe elastic wave dynamics. Since ambient noise recordings contain all kinds of interfering elastic wave types, the accuracy of subsurface material property estimates is compromised.

To investigate the potential to enhance the information available from WEI, we test the method synthetically using more sophisticated wave equations that represent wave propagation in the subsurface more accurately. Starting from a 3D seismic array geometry which provides wavefield gradient information both at the surface and at depth, WEI can be formulated in terms of the full elastic wave equation. From there we track approximations in both wave physics and field acquisition geometries that deplete information about the medium, eventually arriving at the conventional 2D scalar wave equation. These experiments highlight approximations that most deteriorate the solution, allowing us to target future effort to remove them.

One approximation made in all previous WEI studies is to assume that density is constant across the local array. In reality, subsurface density varies both laterally and with depth, yet remains poorly constrained in seismic imaging problems. Accurate density estimates would provide important insight into subsurface properties. This prompts us to test wavefield sensitivities to subsurface density contrasts via WEI. Synthetic results for 3D acoustic media suggest that it is possible to estimate relative density structure with WEI by using a full acoustic formulation for wave propagation along the surface. We show that using a constant density assumption for the medium can be detrimental to subsurface images, whereas the full acoustic formulation of gradiometry improves our knowledge of material properties. It allows us to estimate density as an additional material parameter as well as to improve phase velocity estimates by incorporating approximations to the density structure. By expanding this methodology to the elastic case, we will discuss the feasibility of estimating density with gradiometric WEI in the solid Earth.

How to cite: Faber, M. and Curtis, A.: On Seismic Wave Equation Gradiometric Inversion for Density, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15048, https://doi.org/10.5194/egusphere-egu23-15048, 2023.

EGU23-15050 | Orals | SM2.1

Low-frequency seismic wave sensing using coherent optical fiber networks for metrology 

Paul-Eric Pottie, Mads Tonnes, Maxime Mazouth-Laurol, Hendrix Montlavan-Leyva, Etienne Cantin, Benjamin Pointard, Hector Alvarez-Martinez, Rodolphe Le Targat, Olivier Lopez, Christian Chardonnet, and Anne Amy-Klein

Optical fiber networks are being implemented in several countries aiming at dissemination of ultra-stable time and frequency references. This enables the comparison of optical clocks, which is a key part of the roadmap towards the future redefinition of the International System of Units (SI) second. Furthermore, this enables uses in chronometric geodesy, where the sensitivity of the optical clocks to the gravitation field enables measurements of height differences as low as 1 cm [1].
The frequency signals in the optical fibers are sensitive to acoustic vibrations which are present in the ground, which is the main source of noise to the disseminated signals.
In recent years, this has enabled studies in the use of optical fiber links for the detection of earthquakes [2]. In such an approach, the measurement is the integrated noise over the fiber path. This typically allows for one to several orders of magnitudes longer range as compare to DAS techniques, but with the loss of localization along the fiber. Such integrated approaches include measurements of the total polarization change of the light along the fiber [3], or the total phase change of a coherent ultra-stable laser signal, potentially including distributed sensing techniques in submarine fibers [2,4].

Here, we will present the first quantitative studies on the use of coherent optical fiber links for seismic detection. Using a the fiber network REFIMEVE in France (see Fig. 1), we present studies on the sensitivity of coherent optical fiber links to seismic events. We describe the dependence of the sensitivity to a number of parameters like incident angle, magnitude and distance, and compare the sensitivity of a fiber link with that of conventional seismometers. We show, for a first time to our knowledge, the detection of seismic waves by a coherent optical fiber network, and we study the prospects of using such a network for the localization of earthquakes. Lastly, we discuss the principles and results of a machine learning algorithm, which enables automatic detection of earthquakes in a coherent optical fiber link.

Bibliography:
1. M. Takamoto et al., Test of general relativity by a pair of transportable optical lattice clocks, Nat. Phot., 14 (7), 411–415. doi:30210.1038/s41566-020-0619-8
2. G. Marra et al. , Ultrastable laser interferometry for earthquake detection with terrestrial and submarine cables. Science, eaat4458. doi: 10.1126/science.aat4458279
3. J.C. Castellanos et al. ,Optical polarization-based sensing and localization of submarine earthquakes. In Optical fiber communication conference (OFC) 2022, doi:26210.1364/OFC.2022.M1H.4
4. G. Marra et al., Optical interferometry–based array of seafloor environmental sensors using a transoceanic submarine cable. Science, doi: 10.1126/science.abo193

Figure 1 : Map of the French REFIMEVE fiber network, shown in red lines. Dotted lines indicates indicate the full scale of the planned network, and continuous red lines indicate links used in these studies. Blue lines indicates the linear approximations of the links. All seismometers of the RESIF network is shown by small green triangles, and seismometers used in theses studies are shown by larger, turquoise triangles.

How to cite: Pottie, P.-E., Tonnes, M., Mazouth-Laurol, M., Montlavan-Leyva, H., Cantin, E., Pointard, B., Alvarez-Martinez, H., Le Targat, R., Lopez, O., Chardonnet, C., and Amy-Klein, A.: Low-frequency seismic wave sensing using coherent optical fiber networks for metrology, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15050, https://doi.org/10.5194/egusphere-egu23-15050, 2023.

EGU23-15062 | ECS | Posters on site | SM2.1

Observing and analysing seismicity with a permanet 6C station 

Andreas Brotzer, Heiner Igel, Felix Bernauer, Joachim Wassermann, Robert Mellors, and Frank Vernon

In September 2022, a three-component rotational rate sensor (blueSeis-3A) provided by IRIS has been deployed at the underground vault of the Piñon Flat Observatory (PFO) near San Diego in California. A three-component broadband seismometer (Trillium 240s) is co-located on the granite pier, creating a 6C station for permanent observations of local and regional seismicity and wavefield studies. The permanent record is streamed online via IRIS and freely available with all required metadata (station: BlueSeis at Pinon Flat = BSPF). Additionally, the site offers observations of strain by optical fiber and vacuum laser strainmeters at PFO, allowing to study 7 components of the seismic wavefield in a quiet area with regard to seismic noise, but high seismicity (e.g. San Andreas fault zone, San Jacinto fault zone). Such a setup enables advanced studies of the seismic wavefield. Dense, large-N nodal experiments, temporarily deployed around PFO could provide dense sampling of the seismic wavefield for comparison studies. The seismic array of borehole sensors at PFO is well designed to compute array derived rotations with enables a direct comparison with the rotational record and applied methods. Moreover, the array is employed to compare array analysis with 6C methods (e.g. backazimuth estimation, wavefield separation, source tracking, local subsurface velocity changes). We present characteristics on the 6C station and preliminary analysis results.

How to cite: Brotzer, A., Igel, H., Bernauer, F., Wassermann, J., Mellors, R., and Vernon, F.: Observing and analysing seismicity with a permanet 6C station, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15062, https://doi.org/10.5194/egusphere-egu23-15062, 2023.

EGU23-15265 | ECS | Orals | SM2.1

Towards exploiting the advantages of a Standard telecom multi-fibre cable for volcano monitoring: an example from Mt. Etna 

Sergio Diaz-Meza, Philippe Jousset, Gilda Currenti, Air David, Andy Clarke, Anna Stork, Athena Chalari, and Charlotte Krawzcyk

Distributed Dynamic Strain Sensing (DDSS), also known as Distributed Acoustic Sensing (DAS), is becoming a popular tool for volcano monitoring. The sensing method relies on sending coherent light pulses into an optical fibre and measuring the phase-shift of Rayleigh back-scattered light due to strain on the fibre. This provides distributed strain rate measurements at high temporal and spatial sampling rates. Standard telecom fibres have been conventionally used for this purpose, however engineered fibres are being developed to enhance the back-scattered light, providing up to 100 times improved sensitivity in contrast to the conventional standard fibre. Despite the technical advantages of engineered fibres, standard fibres already have extensive coverage around the Earth surface, and so there is an interest in using the existing telecommunication infrastructure. In this study we compare stack DDSS data from a fibre loops made of several fibres within the same optical fibre cable, with DDSS data measured on an engineered fibre. We analyse how stacking can improve the signal quality of the recorded DDSS data. In an area located 2.5 km NE from the craters of Mt. Etna, we spliced 9 standard fibres together from a 1.5 km long cable to create a single optical path and interrogated using an iDAS unit. At the same time, we interrogated with a Carina unit a 0.5 km engineered fibre installed parallel to the standard multi-fibre cable. Both fibres were interrogated in a common period of 5 days. We use a spatial cross-correlation function to find the channel equivalences between each fibre and then stack them to evaluate the changes in the DDSS data and compare with the engineered fibre data. Our results show that, despite engineered fibres have lower noise, a stack of 5 fibres can achieve a maximum noise reduction of 20% outside of the optical noise band, in comparison to the engineered fibre. We achieved this noise reduction for our specific configuration, and so we show how the stack improvement is dependent on the type of configuration in terms of fibres stacked and length of the fibres. Our findings motivate the exploitation of multi-fibre cables in existing infrastructures, so-called dark fibres, for monitoring volcano and applications to other environments.

How to cite: Diaz-Meza, S., Jousset, P., Currenti, G., David, A., Clarke, A., Stork, A., Chalari, A., and Krawzcyk, C.: Towards exploiting the advantages of a Standard telecom multi-fibre cable for volcano monitoring: an example from Mt. Etna, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15265, https://doi.org/10.5194/egusphere-egu23-15265, 2023.

EGU23-15291 | ECS | Orals | SM2.1

Supporting the completion process of boreholes using combined fiber-optic monitoring technologies 

Johannes Hart, Martin Peter Lipus, Christopher Wollin, and Charlotte Krawzcyk

Efficient, safe and sustainable utilization of geothermal reservoirs depends on reliable well completion and monitoring technologies. Conventional borehole measurement methods can only be used after the completion process and usually show snapshots of the borehole conditions at discrete points in time. Therefore, the successful borehole completion is a risky process and mainly relies on the experience of the driller. By using distributed fiber-optic sensing technologies, it is possible to monitor all along the cable with dense spatial sampling and continuous in real-time.

In this presentation, we give insights into our newest case study in Berlin. A 450 m deep exploration well for an Aquifer Thermal Energy Storage was completed. We installed a fiber optic sensor cable along the whole production tubing, that contained several single-mode and multi-mode fibers in loose tube and tight buffered configuration. This cable allows to simultaneously measure distributed temperature (DTS), distributed acoustics (DAS) and distributed strain (DSS/DTSS) for the entire completion process.

Particularly with a combined analysis and interpretation of the different fiber-optic technologies, conventionally untraceable processes can be visualized. We are able to show changes of subsurface flow paths due to blockages. Processes to be prevented, like caving or bridging can be detected and the proper rise of gravel or cement can be surveyed. Provided to the driller in real time, subsurface uncertainties can be significantly reduced.

Monitoring geothermal wells with a fiber-optic sensing infrastructure is not only a powerful tool to reduce risks during well completion, which can lead to compromised well integrity. The installed equipment and technology can also be used to assess the well integrity over the whole cycle of the well, to ensure a longest possible lifespan.

How to cite: Hart, J., Lipus, M. P., Wollin, C., and Krawzcyk, C.: Supporting the completion process of boreholes using combined fiber-optic monitoring technologies, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15291, https://doi.org/10.5194/egusphere-egu23-15291, 2023.

EGU23-15325 | Posters on site | SM2.1

Observation of the microseismic peak from Distributed Acoustic Sensing (DAS) measurements at the LSBB underground Laboratory 

Olivier Sèbe, Camille Jestin, Amaury Vallage, Stéphane Gaffet, Daniel Boyer, Alain Cavaillou, Jean-Baptiste Decitre, Charly Lallemand, Vincent Lanticq, and Olivier Rousseau

Thanks to its ability to provide dense strain rate measurements along Optical Fiber (OF) cable, the Distributed Acoustic Sensing (DAS) technique spreads over different seismic and geophysical domains. They range from exploration geophysics (Mestayer et al. 2011, Daley et al. 2013), to underground structure imaging (e.g. Ajo-Franklin et al. 2019, Cheng et al. 2021) or seismic activity and background noise monitoring (Jousset et al 2018, Nayak et al. 2021). Beyond the advantage of its dense spatial sampling and given a better understanding of its instrument response (e.g. Lindsey et al. 2020), the detection performance of these new DAS measurements also depends on its ability to precisely characterize the amplitude and phase of the seismic background noise in different environments. According to recent offshore seismic noise studies (Ugalde et al. 2021, Lior et al. 2021, Guerin et al 2022), we propose a study based on DAS recordings of the seismic background noise in an on-land quiet environment.

In 2020, a temporary seismic experiment PREMISE (PREliminary MIga Seismic Experiment) was carried out on the site of the underground low noise Laboratory (LSBB, Laboratoire Souterrain Bas Bruit) at Rustrel, France, in order to study the 3D seismic wave field properties in a pretty well-known underground geological structure. During this experiment, we deployed several kilometers of different OF in the LSBB galleries in order to create a multidirectional DAS array with a total fiber length of 10.5km and several ground-coupling conditions. We reprocessed two hours of “raw” DAS data, recorded with a FEBUS A1-R instrument, with different acquisition parameters to find the best configuration for enhancing the DAS measurement Signal to Noise Ratio. The power spectral density (PSD) of these reprocessed strain time-series reveals a peak in the background noise frequency range [0.08-0.25Hz] for gauge lengths of 90m and 150m. Independently, an estimation of the local strain field has been derived by a geodetic analysis (Spudich et al 1995) of the records from the LSBB broadband seismometers antenna. The comparison of the DAS and seismometers array-derived strain PSD shows a very good agreement with the secondary microseism peak in terms of frequency band, amplitude, and the wave field polarization, especially for DAS strain records processed with gauge-length of several tens of meters.

How to cite: Sèbe, O., Jestin, C., Vallage, A., Gaffet, S., Boyer, D., Cavaillou, A., Decitre, J.-B., Lallemand, C., Lanticq, V., and Rousseau, O.: Observation of the microseismic peak from Distributed Acoustic Sensing (DAS) measurements at the LSBB underground Laboratory, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15325, https://doi.org/10.5194/egusphere-egu23-15325, 2023.

EGU23-15589 | Posters on site | SM2.1

Variations of the system properties of a high-rise building over 1 year using a single station 6C approach. 

Yara Rossi, Konstantinos Tatsis, Yves Reuland, John Clinton, Eleni Chatzi, and Markus Rothacher

We demonstrate that the dynamic response of an engineered structure, including modeshape identification, can be obtained from just a single measurement at one position - if rotation is recorded in combination with translation. Such a single-station approach can save significant time, effort and cost when compared with traditional structural characterization using horizontal arrays. In our contribution we will focus on the monitoring of a high-rise building by tracking its dynamic properties and their variations due to environmental (e.g. temperature) and operational (e.g. wind) conditions (EOCs) over a 1-year period. We present a real-case structural identification procedure on the Prime Tower in Zurich. This is a 36-story tower of 126 m height, with a poured-in-place-concrete core and floors and precast-concrete columns; this concrete core structure, surrounded by a triple-glazed facade, is the third highest building in Switzerland. 
The building has been continuously monitored, over a 1-year period, by an accelerometer (EpiSensor), a co-located rotational sensor (BlueSeis) and a weather station located near the building center on the roof. Roof and vertical seismic arrays were deployed for short periods. The motion on the tower roof includes significant rotation as well as translation, which can be precisely captured by the monitoring station. More than 20 structural modes, including the first 6 fundamental modes, where translations are coupled with rotations, are tracked between 0.3 – 14 Hz. We will also show the variation of natural frequencies due to seasonal but also more short-term effects, in an effort to understand the effect of environmental and operational variability on structural deformation and response. Additionally, an amplification of the modes, not only during strong winds, but also during a couple of Mw 4.0 - 4.4 earthquakes at regional distance has been observed and analysed. The frequency band between 0.3 and 10 Hz is of key interest for earthquake excitation, making an investigation thereof essential. The work closes with a summary of the main benefits and potential in adopting collocated rotation and acceleration sensing for geo-infrastructure monitoring purposes.

How to cite: Rossi, Y., Tatsis, K., Reuland, Y., Clinton, J., Chatzi, E., and Rothacher, M.: Variations of the system properties of a high-rise building over 1 year using a single station 6C approach., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15589, https://doi.org/10.5194/egusphere-egu23-15589, 2023.

EGU23-15841 | Orals | SM2.1

Monitoring of elastic properties using DAS and DTS in a controlled experiment during road construction 

CharLotte M. Krawczyk, Martin P. Lipus, Johannes Hart, Christopher Wollin, Christian Cunow, and Philippe Jousset

Maintenance of infrastructure is costly and difficult to implement systematically when it spreads over wide areas, such as road or pipeline networks. In the monitoring of road ways, conventional methods to control the road integrity rely on discrete measurements in space and time. There is a large demand for innovative technologies that are able to assess the structural integrity as a whole and in regular intervals or even continuously. Distributed fiber-optic sensing opens the opportunity to measure numerous physical quantities such as temperature and strain with high spatial and temporal resolution over tens of kilometers. In addition, it is easily deployable at reasonable cost.

In order to address the issue of asphalt aging due to exposure to heavy traffic loads, we installed a fiber-optic cable into a reworked road interval and recorded fiber-optic data in a controlled experiment with numerous test vehicles of different sizes and weights. The recorded data suggests that elastic properties of the asphalt can be retrieved from the bypassing traffic. Vehicles can be characterized by the number of axes and load on the asphalt composite. In the next phase, we will monitor the aging of the test field to deduce how varying matrial properties can be better identified for geotechnical and geoscience applications.

How to cite: Krawczyk, C. M., Lipus, M. P., Hart, J., Wollin, C., Cunow, C., and Jousset, P.: Monitoring of elastic properties using DAS and DTS in a controlled experiment during road construction, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15841, https://doi.org/10.5194/egusphere-egu23-15841, 2023.

EGU23-16307 | Orals | SM2.1

Local earthquake recordings using Distributed Acoustic Sensing (DAS) at BFO 

Nasim Karamzadeh Toularoud, Ya-Jian Gao, Jérôme Azzola, Thomas Forbriger, Rudolf Widmer-Schnidrig, Emmanuel Gaucher, and Andreas Rietbrock

The application of distributed acoustic sensing (DAS) in seismology is rapidly expanding due to its ability to perform a large number of high-density measurements, i.e., distributed sensing, without using many point sensors, which is cost-effective. DAS application includes vertical seismic profiling, microseismic measurements, and hydraulic fracturing monitoring and mainly focuses on the event detection capability of  DAS data. 

Febus optics DAS interrogator (A1-R) is continuously running at German Black Forest Observatory (BFO) since May 2021, recording RAW data (selectively stored) or strain-rate data (continuously stored). Our study is in the experimental phase and focuses on testing basic concepts of DAS data, i.e., the effect of gauge-length on the amplitude of measurement and comparing the amplitude of DAS with other seismological sensors such as strain-meter array and a STS2 broadband sensor as well as synthetic simulations. Such comparison is performed using background noise characteristics (power spectral density) and examples of local and regional events that are detectable at the BFO site. 

In this study, we show examples of strain rate measurements related to local earthquakes recorded by horizontal fiber optic cables, employing two different DAS interrogators, cable types and coupling of the cables to the ground. We compared simultaneous recordings using Febus A1 DAS interrogator and OptoDAS by Febus optic and Alcatel Submarine Networks (ASN), respectively, and, concluded about the frequency and gauge-length dependent sensitivity of recordings in two cases. In addition, we compare the amplitude of DAS recordings, for example of local earthquakes, with the synthetic strain simulated  at lower frequency bands using the spectral-element method (Salvus) based on 3D media and analytic approach (Qseis) for 1D model. 

 

How to cite: Karamzadeh Toularoud, N., Gao, Y.-J., Azzola, J., Forbriger, T., Widmer-Schnidrig, R., Gaucher, E., and Rietbrock, A.: Local earthquake recordings using Distributed Acoustic Sensing (DAS) at BFO, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16307, https://doi.org/10.5194/egusphere-egu23-16307, 2023.

EGU23-16459 | ECS | Orals | SM2.1

Deep learning approach for detecting low frequency events on DAS data at Vulcano Island, Italy 

Martina Allegra, Gilda Currenti, Flavio Cannavò, Philippe Jousset, Michele Prestifilippo, Rosalba Napoli, Mariangela Sciotto, Giuseppe Di Grazia, Eugenio Privitera, Simone Palazzo, and Charlotte Krawczyk3

Since September 2021, signs of unrest at Vulcano Island have been noticed after four years of quiescence, along with CO2 degassing and the occurrence of long-period and very long-period events. With the intention of improving the monitoring activities, a submarine fiber optic telecommunications cable linking Vulcano Island to Sicily was interrogated from 15 January to 14 February 2022. Of particular interest has been the recording of 1488 events with wide range of waveforms made up of two main frequency bands (from 3 to 5 Hz and from 0.1 to 0.2 Hz).

With the aim of the automatic detection of seismic-volcanic events, different approaches were explored, particularly investigating whether the application of machine learning could provide the same performance as conventional techniques. Unlike many traditional algorithms, deep learning manages to guarantee a generalized approach by automatically and hierarchically extracting the relevant features from the raw data. Due to their spatio-temporal density, the data acquired by the DAS can be assimilated to a sequence of images; this property has been exploited by re-designing deep learning techniques for image processing, specifically employing Convolutional Neural Networks.

The results demonstrate that deep learning not only achives good performance but that it even outperforms classical algorithms. Despite providing a generalized approach, Convolutional Neural Networks have been shown to be more effective than traditional tecniques in expoiting the high spatial and temporal sampling of the acquired data. 

How to cite: Allegra, M., Currenti, G., Cannavò, F., Jousset, P., Prestifilippo, M., Napoli, R., Sciotto, M., Di Grazia, G., Privitera, E., Palazzo, S., and Krawczyk3, C.: Deep learning approach for detecting low frequency events on DAS data at Vulcano Island, Italy, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16459, https://doi.org/10.5194/egusphere-egu23-16459, 2023.

In this study we use distributed acoustic sensing (DAS) on a 41-km-long submarine optical fibre (OF) cable located offshore Toulon, France. We record both the amplitude and frequency of seafloor strains induced by ocean surface gravity waves, as well as secondary microseisms. Combining the analysis of the two types of waves, we identify and localize local sources of secondary microseisms that manifest as Scholte waves generated by the reflection of oceanic gravity waves on the coastline. During the experiment, these local sources represent the most energetic contribution to the seismic noise recorded along the OF and by an onshore broad-band station located near the DAS interrogator. As a result, the characteristics of this noise are closely related to local wave conditions. One major challenge in performing seismic imaging using ambient seismic noise correlations using DAS data is that we cannot solve for the true seismic velocity because the noise wave field is dominated by local sources. To address this, we measure the incident angle of the dominant local noise sources, correct the apparent velocity using the incident angle retrieve from beamforming analysis and generate a 2D model. We then quantify the errors that arise from picking the dispersion curves of the most energetic velocities without correcting from the incident angle. Our results show that there are significant differences in velocities, with differences reaching up to several hundred meters per second. This highlights the importance of correcting these velocities before generating a tomography. Finally we evaluate an alternative strategy for a linear DAS fiber that cannot be use to localized the dominant noise source. We measure the dispersion curve of the slowest Scholte waves recorded and compare it to the corrected dispersion curves of the dominant source. Although this strategy suffers from limitation, it minimizes the error in the velocity model.

How to cite: Guerin, G. and Rivet, D.: Using localized microseismic noise sources to perform high-resolution seismic Imaging of seafloor using Distributed Acoustic Sensing, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16640, https://doi.org/10.5194/egusphere-egu23-16640, 2023.

EGU23-17585 | Orals | SM2.1 | Highlight

Why high spatial resolution matters: narrow fault zone, but big effects observed by Taiwan Milun-fault Drilling and All-inclusive Sensing (Taiwan MiDAS) project 

Kuo-Fong Ma, Li-Wei Kuo, Hsin-Hua Huang, Sebastian von Specht, Chin-Jen Lin, Jing-Shan Ku, Chen-Ray Lin, En-Shi Wu, Chien-Yin Wang, and Wen-Yen Chang

Understanding fault zone dynamics in multi-scale is important to embrace the complexity of the earthquake behavior and its natural system. However, the opportunity to map and observe the fault zone behavior at depth with high spatial resolution are rare as also the challenge itself on targeting and identifying the fault zone at depth. We placed a 3D cross-fault fiber array with a downhole loop from surface to depth of 700m for Hole-A (Hanging wall site, crossing fault at depth), after drilling and coring to a frequent slip fault, Milun fault in a plate boundary zone, which ruptured during the 6 February 2018 Mw6.4 Hualien earthquake, and resulted in severe damage to several tall buildings with tens of casualties and injuries. Then, the surface segment crosses the surface fault rupture zone using commercial fiber, and to another downhole loop of 500m fiber for Hole-B (Footwall site). The high spatial resolution from distributed acoustic sensing (DAS) allows us to characterize the fault zone feature together with the retrieved core and geophysical logs after drilling through this frequent slip zone. This 3D route includes the experiment of using commercial fiber to the future application of surface rupture zone identification for seismic hazard mitigation. The project successfully retrieved the fault core associated with Milun fault zone, which could be also seen in geophysical logs with low velocity and resistivity, and mapped using Optical Fiber Sensing technique of the downhole fiber. Within the Milun fault zone, while a 20m thick fault core with grey and black gouge was discovered, a distinct seismic feature associated with this 20m fault gouge was found by its amplification of the strain records from DAS. This amplification ratio is about 2.5-3 when compared to the channels at deeper depth related to a consolidated rock material.  This amplification factor was frequency and azimuth independently, as genuinely observed from all events (e.g. local, and teleseismic earthquakes) with similar amplification factor. Our study shows that the amplification from this 20m fault gouge zone is mainly from the nature of the heterogeneous medium in elastic constant while crossing the fault zone, especially the fault core. Similar feature at surface but with wider surface rupture zone (~ 200m) was found in DAS data as well although less evidence using commercial fiber, while could be validated from the densely deployed geophones crossing the surface rupture of the 2018 Hualien earthquake. Through the depth, a high-resolution asymmetric feature of this active fault was evidenced from the downhole optical fiber and cores. This fault zone behavior would be hardly seen or confirmed without continuous viewing of the wavefields to this high spatial resolution to meter scale. Although the narrow fault gouge, the nature of its amplification in strain due to its strong material contrast from fault gouge was intriguing, and requires intensive attention to consider the contribution of the fault zone heterogeneity in the medium. This might give hints on the understanding of the observation of earthquake dynamics triggering reported worldwide after the occurrence of a mega-earthquake.

How to cite: Ma, K.-F., Kuo, L.-W., Huang, H.-H., von Specht, S., Lin, C.-J., Ku, J.-S., Lin, C.-R., Wu, E.-S., Wang, C.-Y., and Chang, W.-Y.: Why high spatial resolution matters: narrow fault zone, but big effects observed by Taiwan Milun-fault Drilling and All-inclusive Sensing (Taiwan MiDAS) project, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17585, https://doi.org/10.5194/egusphere-egu23-17585, 2023.

ERE2 – Renewable energy

This study explores the potential of slow-varying components of the earth system to predict the monthly mean wind speeds over the seven homogenous climate zones of India at subseasonal to seasonal time-scales. The following set of predictors are selected for that purpose: sea-surface temperature, mean sea-level pressure, 10 m wind speed, wind speed at 850 hPa, and geopotential height at 850 hPa. With the exception of sea-surface temperature which is obtained from HadISST, the rest of the variables are obtained from the JRA55. Besides, the popular indices such as the Nino 3.4 index and the Dipole mode index are also used as predictors. The forecasts are made at 1, 2, 3, 4, and 5 months of leadtime for the monsoon months of June, July, August, and September when the wind speeds are the highest throughout the country. The regions of significant correlations of the predictor fields with the spatially-averaged wind speeds of each homogenous region are determined using the past 6 month lagged composites. Once identified, the variables over these regions are spatially averaged and are mapped to the 10 m wind speeds from JRA55, since it is the closest representation of observed wind speeds over India. This predictor-based forecasting is carried out using the following approaches: multi-linear regression, decision tree based regression, and K nearest neighbours regression. The models use data from 1958-2018 for training and 2019-2021 for testing. The deterministic predictions are evaluated using mean absolute error (MAE) and the skill compared to a climatological forecast is estimated using the root mean squared error skill score (RMSESS). Results show that different sets of predictor combinations are responsible for giving the best forecasts for individual months and leadtimes. These forecasts have MAE of  around 0.2 m/s and RMSESS values ranging from 0.5-0.7. Although we are looking at deterministic predictions here, a combination of multiple models and predictors used above can lead to the production of ensemble forecasts as well, which will be of further added value to the wind energy sector.

How to cite: Das, A. and Baidya Roy, S.: Exploiting the predictability of global teleconnections to forecast subseasonal to seasonal scale wind speeds over India, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-507, https://doi.org/10.5194/egusphere-egu23-507, 2023.

EGU23-1119 * | Orals | ERE2.1 | Highlight

Meteorological challenges for renewable energy in the High Arctic 

Anna Sjöblom, Matthias Henkies, and Arthur Garreau

A transition to renewable energy is becoming increasingly more urgent in the High Arctic. In Svalbard (78°N), the previously coal based energy system is now, with a short transition period with diesel, moving to a completely renewable off-grid system. Both solar and wind energy are possible contributors to the energy mix. However, no renewable energy systems are specifically designed for the High Arctic and before implementing the systems they must be tested and adapted to Arctic conditions. Since 2020, the world’s northernmost higher education institution, The University Centre in Svalbard (UNIS), has developed a special focus on Arctic renewable energy meteorology, focussing especially on solar and wind energy. This is undertaken in close collaboration with local industry who are switching from coal mining to exporting renewable off-grid systems.

Many of the meteorological processes in the High Arctic are very different from further south with long periods of midnight sun, polar night, complex topography, low temperatures, stable stratification, snow and ice etc. What implications these processes will have on the solar and wind power are mostly unknown. To complicate matters further, numerical models are uncertain and unproved in these areas and there is a need for long-term measurements.

Long-term meteorological measurements to determine the energy potential as well as the impact of the Arctic climate have commenced around Longyearbyen, Svalbard, with a special focus on boundary layer processes. Initial results will be presented, including local wind processes important for wind energy and radiation properties for solar energy. The goal is to identify the most important meteorological processes and adapt the energy solutions accordingly.

How to cite: Sjöblom, A., Henkies, M., and Garreau, A.: Meteorological challenges for renewable energy in the High Arctic, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1119, https://doi.org/10.5194/egusphere-egu23-1119, 2023.

Inclined and flat-plate photovoltaic (PV) solar panels have been widely used in many countries and regions for generating electric power. For exploiting the available solar energy in a region, prior knowledge of this potential is necessary. This work investigates the performance of solar panels in 82 locations in Saudi Arabia by calculating the annual energy received on inclined-plate with tilt angles from 15° – 55° inclined to south and flat-plate that continuously follow the daily motion of the sun.  Calculations are performed using a fixed surface albedo of 0.2 and with a near-real value. The analysis indicates that tilt angles of 20°, 25°, and 30° towards the south are the optimum ones depending on the site. These optimum tilt angles define three distinct solar energy zones in Saudi Arabia. The variation of the total energy in each energy zone on a monthly, seasonal, and annual basis is given. Regression analysis for the total energy as a function of time is derived for each zone. Moreover, the spatial distribution of the annual global inclined solar energy in Saudi Arabia is illustrated in a solar map where the total energy is found to vary from 1612 - 2977 kWhm−2year−1 for the southward-inclined plates and 2159 – 4078 kWhm−2year−1 for the flat-plates across Saudi Arabia. The correction factor, introduced in a recent publication, is used; it is found that the linear relationship between the correction factor and the ground-albedo ratio is general enough to be graphically representable as a nomogram.

How to cite: Farahat, A. and Kambezidis, H.: Solar Potential in Saudi Arabia: Spatio-temporal and Plates-inclination Effects on the Performance of Photovoltaic Solar Panels, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1790, https://doi.org/10.5194/egusphere-egu23-1790, 2023.

In 2021, Saudi Arabia, a leading global oil producer, announced its Middle East Green Initiative with many objectives including reducing carbon emissions by divagating the country away from an oil-based economy and towards renewable. Saudi Arabia has a high potential to become one of the global largest solar energy producers, as it is geographically located on a sunbelt. By 2030, the Saudi government targets building eight solar plants across the country which are expected to produce more than 3,600 MW, enough to power more than 500, 000 homes. However, the vast desert environment in Saudi Arabia increases the dust and aerosol loadings in the atmosphere, which affects the performance of the solar irradiance performance of photovoltaic panels due to the scattering of the solar radiation and the dust deposition on the solar panels. In this work, ground-based data from weather stations located in five Saudi cities: Dammam, Riyadh, Jeddah, Najran, and Arar along with data from the Moderate Resolution Imaging Spectroradiometer (MODIS) are used to estimate solar irradiance and its correlation with atmospheric and meteorological conditions like air temperature, wind, and aerosol physical parameters. We investigate the effect of three major dust storms that blew over different regions in Saudi Arabia on 20 March 2017, 23 April 2018, and 15 April 2021 on solar irradiance. It is found that there is a strong correlation between aerosol optical parameters like Aerosol Optical Depth (AOD), Ångström exponent, and solar irradiance. Maximum AOD (about 2) is recorded over Jeddah on 19 March 2017, (about 2.3) over Riyadh on 20 March 2017, (about 1.5) over Riyadh on 24 April 2018, and (about 0.9) over Najran on 15 April 2021. Large dust events are found to reduce air temperature by a few degrees in the regions affected by dust loadings. The study found large dust loading decreases the DNI, and GHI components on the solar irradiance, while increasing the DHI component over the cities of Jeddah, Riyadh, and Najran. This could be an indication that scattering from dust particles could play a significant role in the solar irradiance intensity. 

How to cite: Labban, A. and Farahat, A.: Effect of Major Dust Events on Atmospheric Temperature and Solar Irradiance Components over Saudi Arabia, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1854, https://doi.org/10.5194/egusphere-egu23-1854, 2023.

EGU23-2107 | Posters on site | ERE2.1

Power generation forecast for a solar plant with a deep-learning method 

Yu-Ting Wu and Chang-Yu Lin

In this study, we perform power generation forecast of a solar farm using deep learning. A long short-term memory (LSTM) network is applied to forecast time series data of the overall power production from a solar farm. An LSTM network can be considered as a recurrent neural network (RNN) looping with input data (e.g., measured power data) over time steps to update the network information. The network information also has records over all previous time steps. One can use an LSTM network to predict subsequent values of a time series (denoted as open loop forecasting) or sequence using previous time steps as input (denoted as closed loop forecasting). Both forecasting methods are built in the LSTM network. Preliminary results show that closed loop forecasting can allow to have predictions of solar power in more time steps, but less accurate than the other method.  

How to cite: Wu, Y.-T. and Lin, C.-Y.: Power generation forecast for a solar plant with a deep-learning method, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2107, https://doi.org/10.5194/egusphere-egu23-2107, 2023.

Wind energy is essential in many decarbonization strategies and potentially vulnerable to climate change. While existing wind climate change assessments rely on regional or global climate models, a systematic investigation of the global-to-regional climate modeling chain is missing. In this presentation, I therefore address the differences in climate change impacts on winds according to  regional and global climate model ensembles under three different future scenarios.

 

I highlight two key limitations, namely (a) the differing representation of land-use change in global and regional climate models which compromises comparability, and (b) the consistency of large-scale features along the global-to-regional climate modeling chain. To this end, I analyze the large EURO-CORDEX ensemble (rcp85: N=49; rcp45: N=18; rcp26: N=22) along with the driving global models (rcp85: N=7; rcp45: N=5; rcp26: N=7), finding evidence that climate change reduces mean wind speeds by up to -0.8 m/s (offshore) and -0.3 m/s (onshore).

 

Moreover, I provide physical explanations for these changes by identifying two key drivers. First, onshore wind speeds drop in the driving global models in regions and scenarios with strong land use change but show no drop in EURO-CORDEX where land use is held constant. Second, offshore wind reductions follow decreases in the equator-to-pole temperature gradient remarkably well with correlations reaching around 0.9 in resource-rich European countries like Ireland, the United Kingdom and Norway, implying that arctic amplification is a severe risk for European offshore wind energy.

 

My results suggest that earlier conclusions of negligible climate change impacts on wind energy might be premature if either land use changes strongly or polar amplification is at or above the range sampled in global climate models. In conjunction with earlier work that demonstrated the relevance of multidecadal wind fluctuations caused by climate variability, these results call for a better inclusion of climate risk in wind energy planning.

 

Reference

 

Wohland, J. Process-based climate change assessment for European winds using EURO-CORDEX and global models. Environ. Res. Lett. (2022) doi:10.1088/1748-9326/aca77f.

How to cite: Wohland, J.: Climate change impacts on winds in Europe: do global and regional climate models tell the same story?, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2317, https://doi.org/10.5194/egusphere-egu23-2317, 2023.

January 2007 was a bad storm month for much of central and northern Europe with a series of extratropical cyclones bringing high winds and precipitation to highly populated areas between Ireland and Russia.  Although Storm Kyrill on 18-19 January 2007 was the most serious for its infrastructure damage and insurance costs, Storm Franz from the preceding week on 11-12 January 2007 was actually more serious for its maritime impacts in western Europe. This contribution takes a closer look at Storm Franz, presenting an overview of its impact to energy infrastructure as well as transportation networks and societal infrastructure damage.  Maritime casualties are reviewed with respect to met-ocean conditions.  An analysis is carried out on water level recorders around the North Sea to assess the storm surge and short period oscillations that may reveal harbour seiches or meteotsunamis.  The results are compared with wave recorders, which had a fairly good coverage across the North Sea in 2007.  The issue of wave damage to offshore infrastructure was highlighted in events associated with Storm Britta on 31 October - 1 November, 2006.  Offshore wind energy in northwest Europe was in a growth phase during this time, and there were questions about the extreme met-ocean conditions that could be expected in the 20 year lifetime of an offshore wind turbine.

How to cite: Kettle, A.: Storm Franz: Societal and energy impacts in northwest Europe on 11-12 January 2007, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3218, https://doi.org/10.5194/egusphere-egu23-3218, 2023.

EGU23-3486 | ECS | Posters on site | ERE2.1 | Highlight

Solar energy potential assessment on urban rooftops using digital surface models 

Xinyuan Hou and Stelios Kazadzis

Rooftop solar photovoltaic (PV) systems have the advantage of producing electricity without air pollution and greenhouse gas emissions, at the same time reducing carbon footprint as well as urban heat island effect. This study aims to assess physical, geographical and economic levels of solar energy potentials in actual atmospheric conditions on urban rooftops, using two municipalities in Athens, Greece as an example. 

We utilize very high-resolution digital surface models for the computation of clear-sky solar irradiance considering surrounding shadows. For all-sky conditions, cloud and aerosol data from 2012 to 2021 are obtained from the Copernicus Atmosphere Monitoring Service radiation service and the ECMWF Atmospheric Composition Reanalysis 4 product, respectively. The goals are to quantify the effect of solar elevation, the shadowing effect from adjacent buildings and constructions, and the effects of clouds and aerosols on the solar radiation availability on the rooftops and to investigate their interconnections. The spatio-temporal resolution of the analyses ranges from individual rooftop to neighborhood scale (approximately 3000 buildings) and from hourly intervals to ten years periods.

The results of the solar potential assessment are made available as a web GIS map for potential public access, intended to aid urban planning and encourage widespread adoption of solar energy in the public and private sectors.

How to cite: Hou, X. and Kazadzis, S.: Solar energy potential assessment on urban rooftops using digital surface models, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3486, https://doi.org/10.5194/egusphere-egu23-3486, 2023.

EGU23-4625 | Posters on site | ERE2.1

Medium and Long-term Forecast of Wind Power Trend Based on Regional Similarity 

Xianxun Wang, Yaru Liu, Defu Dong, and Suoping Wang

Accurate and efficient medium and long-term forecast of wind power can provide technical support for efficient development and utilization of wind resources. Taking into account the regional characteristics of wind resources, the regional similarity factor is introduced into the study of wind power forecasting, and the long-term dependence of wind power, the Long Short-Term Memory method is selected for medium and long-term forecasting of wind power trend, a case study is carried out in five provinces of Northwest China. The results show that the error is reduced by an average of 20.80% compared with the forecast of individual stations, which verifies the effectiveness of the proposed method. Different area division methods result in different effects on improving the prediction accuracy. This study provides a new method and reference for medium and long-term wind resource prediction.

How to cite: Wang, X., Liu, Y., Dong, D., and Wang, S.: Medium and Long-term Forecast of Wind Power Trend Based on Regional Similarity, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4625, https://doi.org/10.5194/egusphere-egu23-4625, 2023.

EGU23-5382 | Posters on site | ERE2.1

The GASPOC project and the global offshore atlases of siting parameters 

Xiaoli Larsén, Marc Imberger, Neil Davis, Jacob Sørensen, Carsten Kofoed, Jim Nielsen, Bjarke Olsen, Jana Fischereit, and Jake Badger

The Global Atlas of Siting Parameters for Offshore and Coasts (GASPOC) project aims at shortening the project development period for offshore wind farms, with faster energy integration, lower capital expenditure and lower operating expense. This value is brought by the partners DHI, DTU Wind, Vento Maritime and DECK1 through automatic data driven downscaling techniques, that are applied to meteorological, ocean and wave modeling and analytics, including the application to real test scenarios. GASPOC provides metocean data, including siting parameters for offshore wind turbines such as extreme winds and turbulence intensity, as well as extreme waves and joint wind-wave statistics. An ensemble of reanalysis data together with the spectral correction method (Larsén et al. 2012) is used to obtain the effective 10-min extreme winds at 50 m, 100 m, 150 m and 200 m, while the calculation of the turbulence intensity at heights above the surface layer also takes the mesoscale turbulence into consideration. We show the data of the siting parameters from GASPOC which support seamless application to strategic planning of offshore wind energy development.

Reference

Larsén X., Ott S., Badger J., Hahmann A. N. and Mann J. 2012: Recipes for correcting the impact of effective mesoscale resolution on the estimation of extreme winds. Journal of applied meteorology and climatology, Doi:10.1175/JAMC-D-11.090, vol 51, No. 3, p521-533.

How to cite: Larsén, X., Imberger, M., Davis, N., Sørensen, J., Kofoed, C., Nielsen, J., Olsen, B., Fischereit, J., and Badger, J.: The GASPOC project and the global offshore atlases of siting parameters, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5382, https://doi.org/10.5194/egusphere-egu23-5382, 2023.

EGU23-5388 | ECS | Posters on site | ERE2.1

Spatial complementary of offshore wind farm Iberian Peninsula sites based on COSMO-REA6 high-resolution reanalysis. 

Noelia López-Franca, Miguel Ángel Gaertner, Enrique Sánchez, Clemente Gallardo, María Ofelia Molina, María Ortega, and Claudia Gutiérrez

The energy transition is a fundamental endeavour in the way towards a zero-carbon future that will allow us to mitigate anthropogenic climate change. There are plans at a European Union level and, also at Iberian Peninsula (IP) one, to strongly increase the installed wind power capacity by 2030, with the aim by 2050 of making Europe the first climate-neutral continent. Onshore wind and solar photovoltaic are currently by far the main renewable technologies installed on the IP, receiving other potential dispatchable energy resources such as offshore wind less attention. This resource should also be considered due to its high energy potential and the increasing difficulty of finding suitable land for new onshore wind farms. Although some areas, such as the western IP, show high potential, there are important spatial constraints for the deployment of floating offshore wind towers, related to wind infrastructure technologies and legislative limits. Together, wind power generation is, by nature, complex, irregular and hard to be forecasted. Thus, increasing interconnections between regions can dampen the impact of wind variability on local wind power generation. An analysis of the spatial complementarity of the top potential floating offshore wind farm sites across IP is then proposed in this work. For this purpose, hourly wind fields from COSMO-REA6 very high resolution reanalysis (0.055º) in the 1995-2018 period were used to compute the wind capacity. The wind speed was vertically interpolated to the hub height of 105 meters of a reference turbine at each grid point between the levels 36-39 (approximately 35 to 178 meters) of the reanalysis by a cubic polynomial function using the least squares fit. Then, a total of 55 potential locations of Iberian commercial floating wind farm projects were manually collected, mainly from publicly available information. Of these, ten potential sites were chosen by applying a methodology that finds the combination of sites that minimizes the coefficient of variation of the aggregate wind power. The first results indicate that, in the period considered, it is more advantageous for the Iberian electricity system to build wind farms farther apart, giving priority to wind farm projects located in the northeast and northwest coastal corners of IP. Thus, as more distant sites are added, the coefficient of variation decreases more than the capacity factor. This behaviour varies slightly by season, with the variation decreasing the most in winter and the capacity factor decreasing the most in summer.

How to cite: López-Franca, N., Gaertner, M. Á., Sánchez, E., Gallardo, C., Molina, M. O., Ortega, M., and Gutiérrez, C.: Spatial complementary of offshore wind farm Iberian Peninsula sites based on COSMO-REA6 high-resolution reanalysis., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5388, https://doi.org/10.5194/egusphere-egu23-5388, 2023.

EGU23-5763 | Posters on site | ERE2.1

Realistic Wake Simulation using the WRF-SADLES System 

Hai Bui and Mostafa Bakhoday-Paskyabi

Simulating wind turbine wakes with high accuracy is crucial for understanding their effects on nearby flow patterns and optimizing the design and operation of wind farms. However, current Large Eddy simulation (LES) models for this purpose often rely on highly idealized boundary layer conditions, which may not capture all relevant realistic processes. In this study, we present the development and application of a Simple Actuator Disc model for Large Eddy Simulation (SADLES) for simulating wakes in realistic conditions. SADLES was developed to utilize traditional thrust and power curves provided by turbine manufacturers, while also achieving an intermediate resolution of a few dozen meters to strike a balance between fidelity and computational cost. SADLES has been integrated into the Weather Research and Forecast (WRF) model, resulting in the WRF-SADLES system. Using this system, atmospheric conditions from ERA5 data were downscaled to a wake-enable scale of 40 m using a system of 5 nested domains. Selected transition events were simulated and the results were validated using real observations from the FINO1 meteorological mast and LiDAR data. Our WRF-SADLES approach represents a promising advancement in the simulation of wind turbine wakes and their impacts on surrounding flow fields.

How to cite: Bui, H. and Bakhoday-Paskyabi, M.: Realistic Wake Simulation using the WRF-SADLES System, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5763, https://doi.org/10.5194/egusphere-egu23-5763, 2023.

European countries are increasing their share of power production from wind and solar energy to mitigate climate change. Also the relative contributions from PV and wind power production in Europe change over time. At present, the installed capacity of photovoltaic (PV) power for all of Europe is smaller than that of wind power with a ratio of 3:4. Future scenarios for the installations of PV and wind power capacities for 2050 suggest that this ratio will substantially change. Namely, the PV power capacity might exceed the wind power capacity with a ratio of 3:2 to 2:1. We test the hypothesis that the weather dependency of anomalies in the PV plus wind power production will change in the future compared to today. Specifically, we examine which synoptic weather patterns are associated with anomalies in the PV plus wind power production for the present and future installed capacities in Europe. To that end, we developed a renewable energy model for the installed capacity of 2019 and 2050. This model allows us to simulate hourly PV and wind power production at 6 km horizontal resolution for all of Europe. We analyze the weather dependency of power-production anomalies by pairing our model output with results of the classification of weather patterns from the German Weather Service. Our results highlight similar weather patterns associated with positive anomalies in the hourly PV plus wind power production for the 2019 and 2050 installation, namely weather patterns with prevailing westerly winds. However, weather patterns associated with negative anomalies strongly change between the two installations. We also assess the dependency of the results on the duration of the production anomalies. Particularly for long production anomalies, the associated weather patterns are different for the 2019 and 2050 installation. One exception is the weather pattern Anticyclonic Southeasterly that is associated with the lowest 10-day power production in Europe for both 2019 and 2050. Regionally, weather patterns have different impacts on different regions in Europe, when comparing the associated patterns between the 2019 and 2050 installation. For instance, anomalously low power production differ for the Iberian peninsula and Southeastern Europe when the two installed capacities are compared. Taken together, our study gives a systematic overview on changes in the weather dependency of anomalies in the mix of PV and wind power between 2019 and 2050.

How to cite: Ho, L. and Fiedler, S.: Weather dependency of European wind and photovoltaic power production for present and future installations, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5812, https://doi.org/10.5194/egusphere-egu23-5812, 2023.

EGU23-5918 | ECS | Posters on site | ERE2.1

AEOLIAN, the new Italian Wind Atlas for local energy planning support 

Martina Aiello, Davide Airoldi, and Alessandro Amaranto

The decarbonization objectives set by the EU Green Deal to increase the renewable generation heavily rely on the contribution of wind energy, both onshore, through the installation of new plants and repowering of existing plants, and offshore. The issuance of the new "Fit for 55" package of measures will result in an increase in the objectives already identified for 2030 for Italy, which in all probability will be set at over 21 GW of installed capacity for onshore wind (i.e., doubling the currently operating power) and at least 3 GW for offshore wind. An informed energy planning of the territory is therefore paramount to efficiently maximize renewable penetration. In these regards, the development of informatic tools aimed at disentangling both resource availability and generation potential can effectively play a key role in supporting optimal technology displacement through space. RSE has worked on these themes since the end of the 1990s, when the first version of the Italian Wind Atlas (ATLAEOLICO) WebGIS was released, providing a support tool for adequate energy planning of the territory. Throughout the years, the Wind Atlas has represented a reference for various stakeholders (wind plants developers, authorities responsible for spatial planning and companies involved in the electricity grid development) who recognized its great utility in quickly identifying the most suitable Italian areas for wind energy exploitation in terms of long-term annual average wind speed and full load hours.  With the purpose that this platform keeps providing tangible support for energy planning, we have worked on both renewing the anemological database and the WebGIS structure, which is the focus of this work.  The new Italian Wind Atlas AEOLIAN provides for a new anemological database consisting in 30 years (1990-2019) of hourly wind data at 1.4 km horizontal resolution (WGS84 UTM32) covering the whole Italian territory and marine areas. Wind trajectories are estimated through the Weather Research and Forecasting (WRF) meteorological model combined with a statistical post-processing based on Analog Ensemble (AnEn). The renewed AEOLIAN WebGIS, developed through the open access framework TerriaJS, integrates standard functions for visualizing and querying data, data download functions and advanced tools to support local energy planning. It shows the spatial distribution of onshore and offshore wind speed [m/s] and full load hours [MWh/MW]. Each variable is computed as the 30 years annual average at the heights of 50, 75, 100, 125 e 150 m. a.s.l. Within AEOLIAN, users can download both variable maps and historical series of wind speed for more accurate evaluations. Besides maps, AEOLIAN also includes a tool for the technical and economical evaluation of a hypothetical wind farm at a local scale. This tool allows assessing the energy performances in terms of the net annual energy production and the average cost of the energy produced, considering local distribution of the wind resource, energy performances of the wind farm and investments and management costs.  

How to cite: Aiello, M., Airoldi, D., and Amaranto, A.: AEOLIAN, the new Italian Wind Atlas for local energy planning support, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5918, https://doi.org/10.5194/egusphere-egu23-5918, 2023.

EGU23-5952 | ECS | Orals | ERE2.1

The Aspire campaign: Assessing the effects of aerosols on solar radiation and energy in SE Europe. 

Dimitra Kouklaki, Ioannis-Panagiotis Raptis, Stelios Kazadzis, Ilias Fountoulakis, Kyriakoula Papachristopoulou, and Kostas Eleftheratos

In recent years, solar power applications are growing rapidly worldwide, to meet the increasing power demand and the sustainable development planning. Estimation of solar radiation availability at surface level, its characteristics and various factors that affect it, play a key role in designing and achieving the optimal performance of systems employing solar energy. Various solar -PV related - applications are using radiative transfer modeling to characterize the radiation field, since accurate surface solar irradiance measurements are not always available, especially in remote regions. Understanding the effect of aerosols to the solar energy potential is highly important for the energy sector as well as for a variety of fields.    In areas and periods where cloudiness is limited and they are in the proximity of particle sources, the significance of aerosol effect is very high.

The objective of this study is to assess the impact of the variability of aerosols on the solar Direct Normal Irradiance (DNI), Global Horizontal Irradiance (GHI) and solar energy, using spectral solar measurements and aerosol optical properties retrievals, in the framework of the one-year experimental campaign (December 2020-December 2021) of the ASPIRE (Atmospheric parameters affecting SPectral solar IRradiance and solar Energy, https://aspire.geol.uoa.gr) project, which was held in Athens, Greece.

Main findings include an assessment of differences among different PV technology and their calculated outputs using actual and standard spectra, linking the differences with aerosol optical properties (optical depth, spectral dependence, absorption). Aerosol optical depth is the major factor of such differences for all PV technologies. Spectral aerosol characteristics affect differently PV technologies as a consequence of different spectral responsivities.

Finally, aerosol effect on solar nowcasting models have been investigated by comparing spectral solar measurements and aerosol properties with model inputs and outputs.

How to cite: Kouklaki, D., Raptis, I.-P., Kazadzis, S., Fountoulakis, I., Papachristopoulou, K., and Eleftheratos, K.: The Aspire campaign: Assessing the effects of aerosols on solar radiation and energy in SE Europe., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5952, https://doi.org/10.5194/egusphere-egu23-5952, 2023.

Probabilistic forecasts based on ensemble simulations of numerical weather prediction models have become a standard tool in weather forecasting and various application areas. However, ensemble forecasting systems tend to exhibit systematic errors such as biases, and fail to correctly quantify forecast uncertainty. Therefore, a variety of post-processing methods has been developed to correct these errors and improve predictions [1]. In particular, machine learning methods based on neural networks have been demonstrated to lead to substantial improvements compared to classical statistical techniques [2].
While post-processing can successfully correct the biases and dispersion errors in the weather variables, its effect but has not been evaluated thoroughly in the context of subsequent forecasts, such as wind and solar power generation forecasts and it is not obvious how to best propagate forecast uncertainty through to subsequent power forecasting models. Therefore, the work presented here will evaluate multiple strategies for applying ensemble post-processing to probabilistic wind and solar power forecasts. We use Ensemble Model Output Statistics (EMOS) as the post-processing method and evaluate four possible strategies: only using the raw ensembles without post-processing, a one-step strategy where only the weather ensembles are post-processed, a one-step strategy where we only post-process the power ensembles and a two-step strategy where we post-process both the weather and power ensembles. The presentation is based on recent work in Phipps et al. (2022) [3] and ongoing other work.

References

[1] Vannitsem, S., et al. (2021). Statistical Postprocessing for Weather Forecasts - Review, Challenges and Avenues in a Big Data World. Bulletin of the American Meteorological Society, 102, E681–E699.
[2] Rasp, S. and Lerch, S. (2018). Neural networks for post-processing ensemble weather forecasts. Monthly Weather Review, 146, 3885–3900.
[3] Phipps, K., Lerch, S., Andersson, M., Mikut, R., Hagenmeyer, V. and Ludwig, N. (2022). Evaluating ensemble post-processing for wind power forecasts. Wind Energy, 25, 1379-1405. 

How to cite: Lerch, S.: Evaluating ensemble post-processing for probabilistic energy prediction, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6644, https://doi.org/10.5194/egusphere-egu23-6644, 2023.

EGU23-6943 | Orals | ERE2.1 | Highlight

Impact assessment of future wind farm characteristics on cluster-scale wake losses in the North Sea 

Nicole van Lipzig and Ruben Borgers

Offshore wind zones are reaching sizes at which they start to affect each other and potentially also alter mesoscale weather systems, impacting the energy production. Here, we assess the impact of future wind farm characteristics, like turbine type and capacity density, on cluster-scale wake losses. For this we use the mesoscale model COSMO-CLM at the km-scale resolution, which skillfully models frequency distributions of wind speed and wind direction at turbine level compared to measurement masts, wind lidars and satellite data. It was found that inter-farm wakes can reduce the long-term capacity factor at the inflow edge of wind farms from 59% to between 55% and 40% depending on the degree of clustering and the size of the upwind farms, for a layout equipped with 5MW turbines at a capacity density of 8.1 MW / km². Moving to next-generation wind turbines (15MW) partly mitigates this degradation, as the total generation over all windfarms (TWh) is increased by 19% under the same wind farm capacity density. On the other hand, increases in the capacity density in this future layout lead to a less than proportional (0.8 to 1) increase in the basin-integrated, total generation as a consequence of more intense intra- and inter-farm wake effects. Generally, wind farm characteristics play an essential role in inter-farm wake losses, which should be included in future wind farm planning.

How to cite: van Lipzig, N. and Borgers, R.: Impact assessment of future wind farm characteristics on cluster-scale wake losses in the North Sea, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6943, https://doi.org/10.5194/egusphere-egu23-6943, 2023.

EGU23-8140 | ECS | Posters virtual | ERE2.1

From solar radiation estimation to solar energy potential in the High Arctic 

Arthur Garreau, Torodd Nord, Anna Sjöblom, and Aleksey Shestov

The High Arctic is a remote region with a harsh climate where communities mainly rely on fossil energy sources. In Longyearbyen, located in the archipelago of Svalbard at 78°N, solar energy is considered as one of the future energy sources. The available solar radiation must therefore be estimated to have solar energy as part of the energy mix. To achieve this goal, the University Centre in Svalbard has maintained a weather station that has recorded ten years of solar radiation data with a Kipp and Zonen CNR1 net radiometer. Additional pyranometers have been installed at other locations, at different altitudes, and with different configurations to establish a more complete atlas of the solar irradiance around Longyearbyen.

The solar irradiance in the High Arctic has different characteristics than that usually encountered at mid-latitudes. There are 24 hours of sunlight during summer and polar nights during winter. When the sun is present, its position and path in the sky differ from further south. In addition, the air mass, atmospheric aerosols, and albedo have an impact on radiation that is peculiar to the Arctic. All those specificities have yet to be completely understood for the Arctic, and hence some uncertainties remain about solar radiation.

A better understanding of the solar radiation received in Longyearbyen will help implement the future solar energy solution for the Arctic. The aim is to accurately estimate solar radiation at high latitudes, capture variability and predictability, and understand which solar cell configuration is optimal. In particular, differences between horizontal and plane-of-array irradiance have been investigated because of the very low elevation angle of the sun. The solar radiation distributions over different time scales have further been assessed using observations. Moreover, the impact of external factors on solar radiation, such as albedo, has been considered. In the future, the collected data will be used to assess Svalbard's solar PV potential.

How to cite: Garreau, A., Nord, T., Sjöblom, A., and Shestov, A.: From solar radiation estimation to solar energy potential in the High Arctic, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8140, https://doi.org/10.5194/egusphere-egu23-8140, 2023.

Near-surface wind fields are altered over mountainous topography, giving rise to complex wind flow patterns due to sheltering, acceleration, channelling, deflections, blocking or recirculation. However, the impact of the resulting spatio-temporal wind fields on wind energy potential remains largely unknown. While wind modelling approaches can describe highly resolved spatio-temporal wind fields in mountainous terrain rather well, wind fields cannot be generated in a reasonable amount of computational time. Models are therefore strongly limited in space and time for many applications. In mountainous regions, wind farm planning is thus much more challenging than in flat regions.

To investigate the variability of wind fields and its impact on wind energy production in mountainous terrain, we applied a computationally efficient statistical downscaling model approach to a small region in the Swiss Alps. This allowed us to analyze the impact of horizontal resolutions on spatial wind speeds and energy yield in a mountainous area. We applied the statistical approach of Helbig et al., 2017 to downscale coarse wind speed values to the fine scale based on local terrain parameters. This approach introduces two dominant local wind-topography interactions: sheltering and speed-up on coarse wind speed. Then, based on the resulting spatio-temporal near-surface wind fields and a common theoretical power curve, we calculated long-term wind energy yield. Through a sensitivity analysis, we assessed the impact of varying horizontal spatial resolutions in the mountainous environment on overall and local wind energy yield. Specifically, we addressed the impact when decreasing horizontal resolutions from grid cell sizes of 100 m down to 5 m. Resulting spatial variations will be discussed as functions of local terrain parameters, as well as wind speeds.

Helbig, N., Mott, R., van Herwijnen, A., Winstral, A. and Jonas, T. (2017): Parameterizing surface wind speed over complex topography. J. Geophys. Res., 122, 651–667.

How to cite: Helbig, N., Hammer, F., and Barber, S.: Characterizing the impact of spatial scales on near-surface wind speed and wind power generation in a mountainous environment, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9025, https://doi.org/10.5194/egusphere-egu23-9025, 2023.

EGU23-9658 | Orals | ERE2.1

Renewable energy forecasting: results of the Smart4RES project and future research directions. 

Georges Kariniotakis and Simon Camal and the Smart4RES Team

The European Horizon 2020 project Smart4RES (http://www.smart4res.eu), which started in 2019 and runs until April 2023, aims at improving modelling and forecasting of weather variables necessary to optimize the integration of weather-dependent renewable energy (RES) production (i.e. wind, solar) into power systems and electricity markets. It gathers experts from several disciplines ranging from meteorology, data science, power systems a.o. It aims to contribute to the pathway towards energy systems with very high RES penetrations by 2030 and beyond.

This presentation has a double objective:

(1) To present a comprehensive overview in terms of KPI improvements of the final results obtained by the project. These results cover thematic objectives including:

  • Improvement of weather and RES forecasting;
  • Streamlined extraction of optimal value from the data through data sharing, data market places, and novel business models for the data;
  • New data-driven optimization and decision-aid tools for market and grid management applications;
  • Validation of new models in living labs and assessment of forecasting value vs costly remedies to hedge uncertainties (i.e. storage). 

The results obtained are numerous. Without being exhaustive, they include: improved forecasting of weather variables with focus on extreme situations and also through innovative measuring settings (i.e. a network of sky cameras); A seamless approach to couple outputs from different ensemble numerical weather prediction (NWP) models with different temporal resolutions; Advances from ultra-high resolution NWPs based on Large Eddy Simulation; Approaches for RES production forecasting aiming at efficiently combining highly dimensionally input (various types of satellite images, NWPs, spatially distributed measurements etc.); Seamless probabilistic RES forecasting covering multiple time frames and data inputs; Resilient energy forecasting. In the front of applications methods are proposed to optimally use forecasts for the management of storage systems coupled with renewables, for the optimal trading of renewables in multiple markets and for grid management optimization and dynamic security assessment. Prescriptive analytics and explainable AI methods are proposed to optimize decision making.  A cost benefit analysis is performed to assess the contribution of different types of data in forecasting problems.

(2) To present hierarchized proposals for future research directions. An international workshop is organized by the project (14/04/2023), where experts are invited to assess where RES predictability stands today and propose research directions for the future. In this presentation we will present the conclusions of this workshop. This will be a useful insight for academics, industrials as well as policy makers in the field.

How to cite: Kariniotakis, G. and Camal, S. and the Smart4RES Team: Renewable energy forecasting: results of the Smart4RES project and future research directions., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9658, https://doi.org/10.5194/egusphere-egu23-9658, 2023.

EGU23-10763 | Posters virtual | ERE2.1

Forecasting surface solar irradiance in Germany using Meteosat Rapid Scanning Service satellite images 

Mathieu Turpin, Sébastien Marchal, and Nicolas Schmutz

Photovoltaic (PV) production is strongly dependent on cloud cover behaviour. It can induce a very high variability of the production which is problematic for a safe and gainful injection into the power grid. Advanced forecasting solutions represent a major key to reliable PV systems. Satellite data are used to provide forecasts from 15 minutes until 6 hours ahead.

To achieve cloud cover forecast, the first step consists in converting two successive satellite images into a cloud index map. Then, the movement of the clouds between these two images is obtained by analysing the optical flow, transformed into a Cloud Motion Vector (CMV) which is then applied on the image taken at T0 to extrapolate it and forecast the various cloud index maps up to T0 + 6h. Finally, the cloud index is combined with a clear sky model in order to compute the effective Surface Solar Irradiance.

Over Europe, raw images are taken by EUMETSAT’s (European Organisation for the Exploitation of Meteorological Satellites) geostationary satellite. The satellite scans the Earth’s full disk in 15 minutes with the PRIME satellite positioned at 0°. However, the Rapid Scanning Service (RSS) scans the northern third of the Meteosat disk every five minutes, enabling more frequent data acquisition and lower delivery time. One satellite is dedicated to this operating mode and is positioned at 9.5°E.

TRUSTPV is a European Union’s Horizon 2020 Research project whose purpose is to investigate and demonstrate the development of O&M-friendly and grid-friendly solar solutions in large portfolios of distributed and utility scale photovoltaics. Within TRUSTPV, we demonstrate the performance improvement provided by using the geostationary meteorological satellite's RSS to obtain images more frequently and therefore improve intraday forecasts. In this work, we forecast cloud cover every 5 minutes with a 5-minute time step. Then, we simulate PRIME operation with forecasts generated every 15 minutes with a 15-minute time step by using the same optical flow and extrapolation algorithms. Moreover, we take into account the latency in the access to the data in real time. The model outputs are compared to 10-minute solar radiation measurements from Deutscher Wetterdienst (DWD) stations located in Germany over the period ranging from 2021-09-01 to 2022-08-31. We determine the quarterly performance in order to study the seasonal effects. The results are also expressed in terms of relative Root Mean Scare Error (RMSE), RMSE Skill Score, Mean Absolute Error (MAE), MAE Skill Score, and mean bias error.

Comparisons between forecasted surface solar irradiance at 30 minutes of time horizon and co-located pyranometric measurements show an improvement for all sites with a decrease of MAE around 4%. This gain brought by the RSS will improve the quality of power production forecasts of PV plants.

The research leading to these results has received funding from the Horizon 2020 Research and invention Programme, under Grant Agreement No 952957, Trust-PV project.

How to cite: Turpin, M., Marchal, S., and Schmutz, N.: Forecasting surface solar irradiance in Germany using Meteosat Rapid Scanning Service satellite images, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10763, https://doi.org/10.5194/egusphere-egu23-10763, 2023.

EGU23-11429 | ECS | Posters on site | ERE2.1

Improvements and validation of nextSENSE solar energy nowcasting and short-term forecasting system 

Kyriakoula Papachristopoulou, Ilias Fountoulakis, Alkiviadis F. Bais, Basil E. Psiloglou, Charalampos Kontoes, Maria Hatzaki, and Stelios Kazadzis

Solar energy is one of the main sources of renewable energy nowadays. Since there is a strong dependence of solar power generation on the presence of clouds and aerosols, operational nowcasting and short-term forecasting of solar resources are essential for its integration into the grid.

The aim of this study is the assessment of the downwelling surface solar irradiation (DSSI) estimates from the nextSENSE operational service. This service uses as input earth observational data for clouds (EUMETSAT), aerosols (Copernicus Atmosphere Monitoring Service - CAMS) and other important atmospheric parameters to the fast radiative transfer model (RTM) techniques (look-up table – LUT and multi-parametric equations) in order to derive DSSI in real time over Europe and North Africa in high spatial resolution (5 km at sub-satellite point), every 15 min. Recent modifications relative to the older versions are: (i) the use of multi-parametric equations to obtain the effect of clouds from cloud optical thickness (COT) instead of using Artificial Intelligence techniques, and (ii) the use of more detailed LUT. Forecasted DSSI values are also produced up to 3-hours ahead with a 15-min time step by applying a cloud motion vector (CMV) technique to the COT product based on Meteosat second generation (MSG) satellite data.

The new modeled (nowcasted and forecasted) DSSI values were validated against ground-based global horizontal irradiance measurements from pyranometers operating at the Baseline Surface Radiation Network (BSRN) stations and at two additional stations, these of Athens and Thessaloniki, Greece, for the year 2017. The nextSENSE forecasted DSSI values were also benchmarked against the smart-persistence forecast method. The performance of the modeled DSSI values were assessed for different cloud conditions in terms of real cloud modification factor (CMF) values derived by ground-based measurements in conjunction with a clear sky model. Additionally, the effects of aerosol related inputs for estimating DSSI were quantified by comparing the utilized CAMS aerosol optical depth (AOD) forecasts against surface retrievals of the AERONET network.

Acknowledgements

This study was funded by the European Commission project EuroGEO e-shape (grant agreement No 820852).

How to cite: Papachristopoulou, K., Fountoulakis, I., Bais, A. F., Psiloglou, B. E., Kontoes, C., Hatzaki, M., and Kazadzis, S.: Improvements and validation of nextSENSE solar energy nowcasting and short-term forecasting system, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11429, https://doi.org/10.5194/egusphere-egu23-11429, 2023.

EGU23-12367 | ECS | Posters on site | ERE2.1

Projected Changes in Türkiye's Wind Energy Potential Using Next-Generation Climate Models and Scenarios 

Zekican Demiralay, M. Tufan Turp, Nazan An, and M. Levent Kurnaz

Renewable energy is a cornerstone in reducing greenhouse gas emissions and, accordingly, mitigating changes in the global climate system. Wind energy is becoming more common among all renewable energy sources used for electricity generation in terms of generation capacity, rapid growth and technological maturity. The share of wind energy in Türkiye's total electricity production, whose installed capacity has been increasing in recent years, has nearly tripled in the last decade. However, given that wind energy potential varies with wind speed, even small changes in future wind patterns and characteristics can strongly affect future wind power generation dependent on projections. For this purpose, in this study, Türkiye's mid-future (2031-2060) wind energy potential is examined under optimistic (SSP2-4.5) and pessimistic (SSP3-7.0) scenarios. In the study, 0.25° x 0.25° spatial resolution CMIP6 models from the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6) dataset were used. The results point to regional differences in Turkey's mid-future (2031-2060) wind energy potential.

Acknowledgement: This research was supported by DaVinci Energy Investments and Consulting Industry and Trade Inc.

How to cite: Demiralay, Z., Turp, M. T., An, N., and Kurnaz, M. L.: Projected Changes in Türkiye's Wind Energy Potential Using Next-Generation Climate Models and Scenarios, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12367, https://doi.org/10.5194/egusphere-egu23-12367, 2023.

EGU23-12949 | Orals | ERE2.1

Post-processing and high-resolution downscaling of subseasonal ensemble forecasts with focus on renewables using statistics and machine learning 

Irene Schicker, Markus Dabernig, Petrina Papazek, Theresa Schellander-Gorgas, and Michael Tiefgraber

In the past decade, significant advances were made in improving the S2S and seasonal prediction using mainly numerical weather prediction models (NWP) and in some cases climate models for generating the predictions. Recently, the application of these models in real time forecasting through the S2S Real-Time Pilot Initiative (Robbins et al., 2020) was evaluated and is ongoing. There are, however, drawbacks. Computational costs for performing one forecast cycle are high (RAM, storage, ensemble for uncertainty) and limit the spatial, and to some extent temporal, resolution which are currently roughly 1.5° in spatial and at most 6-hourly in temporal resolution. Both resolutions are not sufficient for small scale renewable production sites.

 

In renewable energy applications, these time scales are getting more important as they can adapt their resource management strategies based on predictions of possible load/heating and cooling demand via anomalies to temperature, wind, precipitation amount, effects on the markets can be better estimated for trading, and scheduling of maintenance works. Thus, at least higher spatial resolutions could help improving the management and planning of these tasks.

 

Within the SSSEA project (SubSeasonal to Seasonal Ensemble prediction and Application), in project phase I, different methods for post-processing and downscaling the S2S challenge data to 1 km resolution and actual values instead of anomalies were implemented. The statistical methods EPISODES, GMOS, and SAMOS were adapted to be able to work with different time scales compared to their initial implementations (seasonal/hourly) and machine learning based methods were developed from scratch using a feed forward neural network, a Unet-based model, and a Random Forest. Temperature, precipitation, and in the currently ongoing project phase II, the wind components of the ECMWF S2S model were downscaled to daily analysis fields based on the INCA model.

 

For wind energy applications, specific indices were developed and applied to the downscaled results.  Verification and definition of suitable metrics is crucial to assess the skills of the different methodologies considered and a wide range of aspects and metrics were considered. Results on both grid and station verification for appx. 250 sites in Austria across nearly all altitude ranges show that all post-processing models are able to improve the ECMWF ensemble forecasts for the parameters considered, though, depending on lead time and season, differences in the models’ skill are visible. Furthermore, for most of the initial times and leadtimes in the forecast/testing period of 2020 we were able to outperform also the climatology. To assess the impact on renewable energy production, different indices were derived and evaluated with focus on wind energy and hydrology in project phases I and II. Results of SSSEA show clearly the added value of the post-processed and downscaled subseasonal predictions for both parameters and specified indices.

How to cite: Schicker, I., Dabernig, M., Papazek, P., Schellander-Gorgas, T., and Tiefgraber, M.: Post-processing and high-resolution downscaling of subseasonal ensemble forecasts with focus on renewables using statistics and machine learning, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12949, https://doi.org/10.5194/egusphere-egu23-12949, 2023.

EGU23-13992 | Orals | ERE2.1 | Highlight

Towards a paradigm of explainable AI applied in energy meteorology 

Konstantinos Parginos, George Kariniotakis, Ricardo Bessa, and Simon Camal

Standard practice of decision-making in energy systems relies largely on complex modeling chains to address technical constraints and integrate numerous sources of uncertainty. The increased penetration of Renewable Energy Sources (RES) such as solar and wind plants adds complexity due to the weather dependency of their electricity production. Artificial Intelligence (AI) based tools have proven their efficiency in different applications in the energy sector ranging from forecasting to optimization and decision making. They permit to simplify modeling chains and to improve performance due to higher learning capabilities compared to state-of-the-art methods. However, decision-makers of the energy sector need to understand how decision-aid tools construct their outputs from the data. AI-based tools are often seen as black-box models and this penalizes their acceptability by end-users (traders, power system operators a.o.). The lack of interpretability of AI tools is a major challenge for the wider adoption of AI in the energy sector and a fundamental requirement to better support humans in the decision-aid process. Agents of energy systems expect very high levels of reliability for the various services they provide. As energy systems are impacted by multiple uncertainty sources (e.g. available power of RES plants, weather and meteorological conditions, market conditions), developed AI tools should not only be performant on average situations but be able to guarantee robust solutions in the case of an extreme event. Therefore, our research focuses on understandable representations of data-driven decision-aid models for human operators in the energy sector. In order to enhance the interpretability of the AI models, a technique borrowed from the computer science domain is explored and further developed. Genetic programming and more precisely Symbolic Regression is used to derive a symbolic representation for the data-driven model that can take the form of a single equation. This equation results according to a specific reward function. The optimal solutions are selected naturally mimicking the biological theory of survival of the fittest. The main outcome is the production of symbolic representations of the AI models that require minimum changes when applied to different case studies. In this presentation a real-world use case is considered, to demonstrate the added value of the proposed tools for decision-making when trading the production of wind and solar power plants to the day-ahead market. An annual period of data is considered to train and test the proposed model. The typical modeling chain involves as many as 12 models for forecasting RES production, weather and meteorological conditions, together with stochastic optimization to derive trading decisions. A single AI-based model here replaces this complex chain. Such simplification is a significant enhancement to the modeling chain interpretability and facilitates trust to the human decision-maker. This work is carried out in part in the frame of the European project Smart4RES (Grant No  864337) supported by the H2020 Framework Program and in part in the frame the Marie-Curie COFUND project Ai4theSciences (Grant No  945304)

How to cite: Parginos, K., Kariniotakis, G., Bessa, R., and Camal, S.: Towards a paradigm of explainable AI applied in energy meteorology, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13992, https://doi.org/10.5194/egusphere-egu23-13992, 2023.

EGU23-14098 | ECS | Posters on site | ERE2.1

Offshore wind energy climate projections for the European region 

Stefano Susini and Melisa Menendez

The wind energy sector is experiencing a solid expansion towards the open sea, where higher-quality resources are available. This tendency is slowed down by the uncertainties in metocean characterization, with the wind playing a significant role as it represents both an action and a resource for the wind plant. The present study aims to investigate the climate change impact on the marine wind conditions, focusing on mean and extreme values.

Atmospheric circulation patterns over the European seas are classified based on combinations of the atmospheric sea level pressure and the directional wind speed data from the ERA5 reanalysis (1985-2015). These present climate patterns are then used to assess the performance of several General Circulation Model simulations from the sixth Climate Model Intercomparison Project (CMIP6) during the present climate. The best-performing models are then analyzed to provide projections of mean and extreme wind conditions in multiple shared socio-economic scenarios (SSP1-2.6, SSP2-4-5, and SSP5-8.5) and future horizons (2030-2060 and 2700-2100).

Results show a general decrease in the mean offshore wind speed over the European region, more intense in the Mediterranean Sea, while extreme wind speed will increase up to 3% along the Atlantic coast of Europe. The southeastern Atlantic coast appears to be favored in the analyzed climate change scenarios, as the extreme events are projected to reduce their intensity, while the wind resource is not expected to vary significantly.

How to cite: Susini, S. and Menendez, M.: Offshore wind energy climate projections for the European region, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14098, https://doi.org/10.5194/egusphere-egu23-14098, 2023.

EGU23-14422 | ECS | Posters virtual | ERE2.1

Use of Several Sources of Spatio-temporal Information to Improve Short-term Photovoltaic Power Forecasting. 

Kevin Bellinguer, Robin Girard, Guillaume Bontron, and Georges Kariniotakis

In recent years, the share of photovoltaic (PV) power in Europe has grown: the installed capacity increased from around 10 GW in 2008 to nearly 185 GW in 2021. Due to the intermittent nature of PV generation, new challenges arise regarding economic profitability and the safe operation of the power network. To overcome these issues, a special effort is made to develop efficient PV generation forecasting tools.

Several sources of information are currently investigated in the literature. Each one possesses different characteristics, which make them horizon-specific. For short-term forecasting (i.e. from a few minutes to 6-hour ahead), endogenous inputs, namely past PV production measurements, are typically the main drivers. With the development of PV plants, and the advances in smart monitoring and measurements, we observe a paradigm shift from temporal- to spatio-temporal (ST)-based forecasting models. This family of models considers features that exploit ST correlations in the data, such as observations from spatially distributed portfolios of PV plants. This new paradigm offers power producers the possibility to economically value information from geographically distributed plant networks in the form of forecast accuracy improvements, and prepares the ground for a data-sharing market.

Depending on its distribution or density, a PV network may partially account for the complex ST processes at stake (e.g. mainly sites located upwind or crosswind). To fill this gap, satellite-based observations are an appealing option. With recent developments, geostationary satellites can capture images of Earth at a temporal resolution of less than an hour, which enables operational uses. Contrary to the spatial inflexibility inherent to PV networks, satellite-based observations offer the possibility of covering the whole vicinity of the site location, and much more. In that context, relevant features selection tools need to be considered.

In this work, we propose the following contributions to the state of the art. Traditionally in the literature, observations from spatially distributed units and satellite-derived information are used separately. We propose an incremental approach to assess the impact of one or several sources of data on the forecasting performances of the considered regression model. This approach shows that the combination of various sources of ST information leads to higher accuracy than when inputs are considered individually. This is assumed to result from the difference in spatial resolutions of both features. In this specific case study, we highlight the limits of the PV plants portfolio through an analysis of the local topography and wind distribution at several altitudes Then, we consider cloud opacity maps obtained from infrared channels. Despite being under-represented in the literature (only two studies have been found), infrared channel-based data present the advantage of offering nighttime observations of cloud cover, which contributes to improving early morning forecasts.

The proposed approaches are evaluated using 9 PV plants in France and for a testing period of 12 months.

How to cite: Bellinguer, K., Girard, R., Bontron, G., and Kariniotakis, G.: Use of Several Sources of Spatio-temporal Information to Improve Short-term Photovoltaic Power Forecasting., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14422, https://doi.org/10.5194/egusphere-egu23-14422, 2023.

Solar energy from photovoltaics (PV) is a major contributor to the power production, e.g., in Germany, with a growing share. It is a major contributor to renewable power production but highly volatile as it is heavily influenced by atmospheric conditions. Especially shading by clouds can change within seconds to minutes and cause ramps in irradiance and solar power production. Accurate short-term predictions (nowcasts) of irradiance for the next minutes can help to alleviate the impact of this volatility and improve the integration of solar power into energy grids. One approach for nowcasting is the use of all-sky imagers (ASI), ground based fisheye cameras which capture the current cloud situation. Therefore, cloud information is extracted from current images, future cloud states are extrapolated and converted into an irradiance nowcast. Despite substantial progress in the quality of the applied methods, current ASI nowcasting models still exhibit significant nowcast errors and struggle to reliably outperform persistence nowcasts for all situations. Therefore, we assessed the implications for nowcast performance of two common fundamental simplifications of ASI nowcasting models. Firstly, cloud evolution is often modelled by advection, i.e. simple displacement over time. Growth, shrinking or reshaping of clouds is usually neglected in the models. Additionally, the ASI viewing geometry may introduce a misrepresentation of the depicted cloud scene, which is also commonly neglected. The ASI views surrounding clouds from a single ground position and under varying angles. For direct irradiance however, the horizontal distribution of clouds and their intersection in the direction of the sun is essential. While ASI images are usually reprojected to comply with the required horizontal representation, the original difference in actual and required viewing geometry cannot be fully compensated. E.g., breaks between distant clouds may not be clearly visible by the ASI although modulating the irradiance. Kurtz et al. (2017) demonstrated a major impact by this geometric limitation. We applied a nowcasting model to synthetic ASI images of a simulated cloud scene to extend this previous study and analyze the errors introduced by both of the two commonly used simplifications of ASI nowcasting models. A large fraction of the nowcasting error is attributable to the simplifications, which implies a systematic baseline error of common ASI nowcasting models. While the implementation of more evolved cloud evolution and a better representation of relevant cloud geometry are challenging, this work indicates, that efforts to implement these improvements in ASI nowcasting models are a chance for a leap in performance of future nowcasting models.

 

Kurtz, B., Mejia, F., and Kleissl, J.: A virtual sky imager testbed for solar energy forecasting, Solar Energy, 158, 753–759, https://doi.org/10.1016/j.solener.2017.10.036, 2017.

How to cite: Gregor, P., Zinner, T., and Mayer, B.: How good can we get? – An analysis of systematic errors in common models for all-sky imager based irradiance nowcasting for solar energy, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14645, https://doi.org/10.5194/egusphere-egu23-14645, 2023.

EGU23-14674 | Posters on site | ERE2.1

IEA Wind Task 51 Forecasting for the Weather Driven Energy System 

Gregor Giebel, Caroline Draxl, Helmut Frank, John Zack, Corinna Möhrlen, George Kariniotakis, Jethro Browell, Ricardo Bessa, and David Lenaghan
The energy system needs a range of forecast types for its operation in addition to the narrow wind power forecast. Therefore, the group behind the former IEA Wind Task 36 Forecasting for Wind Energy (running 6 years, from 2016-2021) has broadened its perspective on forecasting issues in part by reaching out to other IEA Technology Collaboration Programmes such as the ones for PV, hydropower, system integration, hydrogen etc. The three existing Work Packages (WPs) on NWP Improvements (WP1), Power and Uncertainty Forecasting (WP2) and optimal use of Forecasting Solutions (WP3), are complemented by thirteen work streams in a matrix structure.
 
The three work packages span three distinct areas of challenge in forecasting for the weather driven energy system. The first area is the continuing effort to improve the representation of physical processes in weather forecast models through both new high performance initializations and tailored parameterizations. The second area is the heterogeneity of the forecasters and end users, the full understanding of the uncertainties throughout the modelling chain and the incorporation of novel data into power forecasting algorithms. A third area is representation, communication, and use of these uncertainties to industry in forms that readily support decision-making in plant operations and electricity markets.
 
Task 51 will focus on facilitating communication and collaborations among international research groups engaged in the improvement of the accuracy and applicability of forecast models and their utility for the stakeholders in the wind industry, in the power sector and in the energy system.
 
The first two activities of Task 51 were (1) a workshop in Dublin on the State of the Art and Research Gaps for Forecasting. The results of the workshop will be compiled into a journal article, and (2) the publication of the IEA Recommended Practice for the Implementation of Renewable Energy Forecasting Solutions as an open access book by Elsevier. Other planned activities include further workshops on seasonal forecasting with emphasis on Dunkelflaute, storage and hydro in May 2023, a workshop on minute-scale forecasting (2024), and a workshop on extreme power system events (2025). The results of these interactive workshops will be compiled into a journal articles. Additionally, the Recommended Practice on Forecast Solution Selection will be updated to reflect the broader perspective.
 
Reference: Corinna Möhrlen, John Zack, Gregor Giebel (eds): IEA Wind Recommended Practice for the Implementation of Renewable Energy Forecasting Solutions. Elsevier, 348 pages, Nov. 2022. ISBN: 9780443186813. Download the individual chapters from https://www.sciencedirect.com/book/9780443186813/iea-wind-recommended-practice-for-the-implementation-of-renewable-energy-forecasting-solutions.

How to cite: Giebel, G., Draxl, C., Frank, H., Zack, J., Möhrlen, C., Kariniotakis, G., Browell, J., Bessa, R., and Lenaghan, D.: IEA Wind Task 51 Forecasting for the Weather Driven Energy System, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14674, https://doi.org/10.5194/egusphere-egu23-14674, 2023.

EGU23-14723 | Posters on site | ERE2.1

Analysis of Wind Energy production conditions in Catalonia (NE Spain) based on multiple data sources: station data, ERA-5 Reanalysis, WRF/CALMET, and EURO-CORDEX.  

Enric Aguilar, Oleg Skrynyk, Jon Xavier Olano Pozo, Anna Boqué Ciurana, and Antoni Domènech