GI – Geosciences Instrumentation & Data Systems

GI1.1 – Open session on geoscience instrumentation and methods

EGU22-1625 | Presentations | GI1.1

A stand-alone, modular Sensorbox to exploit the potential of automotive lidar for geoscientific applications

Stefan Muckenhuber, Birgit Schlager, Thomas Gölles, Tobias Hammer, Christian Bauer, Victor Exposito Jimenez, Wolfgang Schöner, Markus Schratter, Benjamin Schrei, and Kim Senger

Today, the automotive industry is a leading technology driver for lidar systems, because the largest challenge for achieving the next level of vehicle automation is to improve the reliability of the vehicles’ perception system. High costs of mechanically spinning lidars are still a limiting factor, but prices have already dropped significantly during the last decade and are expected to drop by another order of magnitude in the upcoming years thanks to new technologies like micro-electro-mechanical systems (MEMS) based mirrors, optical phased arrays, and vertical-cavity surface-emitting laser (VCSEL) sources. To exploit the potential of these newly emerging cost-effective technologies for geoscientific applications, we developed a novel stand-alone, modular Sensorbox that allows the use of automotive lidar sensors without the necessity of a complete vehicle setup. The novel Sensorbox includes a real-time kinematic differential global positioning system (RTK DGPS) and an inertial measurement unit (IMU) for georeferenced positioning and orientation. This setup enables measuring geoscientific processes and landforms reliably, at any remote location, with very high spatial and temporal resolution, and at relatively low costs. The current setup of the Sensorbox has a 360° field of view with 45° vertical angle, a range of 120m, a spatial resolution of a few cm and a temporal resolution of 20Hz. Compared to terrestrial laser scanners (TLS), such as the Riegl VZ-6000, automotive lidar sensors provide advantages in terms of size (40cm vs. 10cm), weight (20kg vs. 1kg), price (150k€ vs. 10k€), robustness (IP64 vs. IP68), acquisition time/frame rate (1h vs. 20Hz) and eye safety (class 3 vs. class 1). They can therefore provide a very useful complement to currently used TLS systems that have their strengths in range (6000m vs. 100m) and accuracy (1cm vs 5cm) performance. Automotive lidar sensors record high-resolution point clouds with very high acquisition frequencies, resulting in a data stream with order 10^6 points per second. To efficiently work with such large point cloud datasets, the open-source python package ‘pointcloudset’ was developed for handling, analysing, and visualizing large datasets that consists of multiple point clouds recorded over time.

How to cite: Muckenhuber, S., Schlager, B., Gölles, T., Hammer, T., Bauer, C., Exposito Jimenez, V., Schöner, W., Schratter, M., Schrei, B., and Senger, K.: A stand-alone, modular Sensorbox to exploit the potential of automotive lidar for geoscientific applications, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1625, https://doi.org/10.5194/egusphere-egu22-1625, 2022.

EGU22-2035 | Presentations | GI1.1

Topographic and photogrametric techniques applied to the study of the morphology of ravines in Campana city, Buenos Aires, Argentina

Leandro Serraiocco, Diego Barbero, Melina Santomauro, Sandra Peyrot, and Andrea Maroni

Abstract

The comprehensive study of the stability of ravines includes various aspects to be considered. One of them, interesting in this case, is the characterization of the morphology of the slopes, which due to their high inclination, presence of vegetation and irregularity in the surface, making it difficult to achieve this objective.

In the present study, we proceeded to study a ravine, located on the right bank of the Paraná de las Palmas river, in the town of Campana, northeast of the province of Buenos Aires. This work was focused on the surroundings of the coordinates 39º9'30.40 ”S 58º57'14.60” where lays a slope with structural conditions of interest. The morphology of the ravine in this area was studied in order to obtain a more precise assessment of the exposed surface and therefore a correct geometric and mass estimation of the slope.

For this propuse, an analysis of elevation models obtained from topographic surveys carried out with Drone and Total Station and, georeferenced with GPS equipment along the slope, was carried out. From there, the reliability of the applied methods and the results obtained could be evaluated comparatively.

All this information was complemented with a photographic record and available information on the environment to achieve a complete evaluation of the condition of the ravine in this area.

The importance of this work lies in the possibility of testing different methods and contrasting the results obtained using topographic and photogrammetric equipment and a combination of them. This will allow the characterization of slopes to be scaled over larger portions considering that this is part of a larger study along the Paraná river ravine. The greater reliability in the morphological results obtained is considered to be of significant utility for estimating the stability of the slopes, an aspect of interest to evaluate the geological danger and evaluate different engineering solutions.

Key Words: Ravine, Slope, Río Paraná, Argentina, Geological Risk, Drone.

           

How to cite: Serraiocco, L., Barbero, D., Santomauro, M., Peyrot, S., and Maroni, A.: Topographic and photogrametric techniques applied to the study of the morphology of ravines in Campana city, Buenos Aires, Argentina, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2035, https://doi.org/10.5194/egusphere-egu22-2035, 2022.

EGU22-4278 | Presentations | GI1.1

Performances of express mode vs standard mode for d18O, dD and 17O-excess with a Picarro analyzer

Amaelle Landais, Benedicte Minster, Alexandra Zuhr, Magdalena Hoffmann, and Elise Fourré

The recent development of optical spectroscopy enabled the development of the use of water isotopes in climate, environment and hydrological studies. An increasing number of studies also includes the most recent parameter 17O-excess as an indicator for kinetic fractionation effects in the water cycle. However, for some applications such as ice core science, the 17O-excess signal to be measured is very small, of the order of 10 – 20 ppm and it is a big analytical challenge to obtain the requested precision.

Here, we present results of performance of the new express mode and the standard mode developed for d18O, dD and now also 17O-excess for a Picarro analyzer. In the standard mode, there is a new injection of water vapor lasting 4.5 minutes every 10 minutes. To get rid of memory effect, the first injections are discarded or a correction is applied which depends on the difference in water isotopic composition between the measured sample and the previous one. For each new sample measured with the express mode, the sequence begins with 6 injections of water vapor in the cavity of 40 secondes each to get rid of the memory effect. It is followed by injections of water vapor lasting 2 minutes every 4 minutes. The advantage of the express mode is to avoid the memory correction and to decrease the measurement time. It thus permits to run more replicates which is important to improve the accuracy of the measurements, especially 17O-excess. We present here results of several series of samples and standards of different water isotopic composition (d18O ranging from -54 to 0 ‰) ran three times with both the standard and the express modes and compare the performances of the two modes.  

How to cite: Landais, A., Minster, B., Zuhr, A., Hoffmann, M., and Fourré, E.: Performances of express mode vs standard mode for d18O, dD and 17O-excess with a Picarro analyzer, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4278, https://doi.org/10.5194/egusphere-egu22-4278, 2022.

EGU22-7123 | Presentations | GI1.1

SIOS’s Earth observation and remote sensing activities toward building an efficient regional observing system in Svalbard

Ann Mari Fjæraa, Shridhar D. Jawak, William Harcourt, Sara Aparício, Veijo Pohjola, Bo Andersen, Christiane Hübner, Inger Jennings, Ilkka Matero, Øystein Godøy, and Heikki Lihavainen

This study provides an overview of the Earth observation and remote sensing activities of Svalbard Integrated Arctic Earth Observing System (SIOS) undertaken when building an observing system for sustained measurements in and around Svalbard to address Earth System Science (ESS) questions. SIOS research infrastructures are distributed across and around Svalbard for acquiring long-term in situ observations. These in situ measurements are not only useful for various ground-based studies, but also applicable for calibration and validation (Cal/Val) of current and future satellite missions e.g. Copernicus Imaging Microwave Radiometer (CIMR), Radar Observing System for Europe - L-Band (ROSE-L ) or Sentinel-1,2, Copernicus Polar Ice and Snow Topography Altimeter (CRISTAL), Sentinel-5 Precursor, and Copernicus Hyperspectral Imaging Mission for Environment (CHIME). Better integration of in situ and satellite-based measurements is crucial for building a coherent network of observations to fill observational gaps. Additionally. complementing in situ measurements with satellite data is a prime necessity to generate operational reliable geoinformation products using traditional and advanced methods, for example, mapping vegetation extent in Svalbard using Sentinel-2 data complemented with in situ measurements of spectral reflectance collected by SIOS infrastructure. SIOS’s remote sensing activities are developed in SIOS knowledge centre (SIOS-KC) under the direction of the remote sensing working group (RSWG). This study highlights our current activities, goals for the next five years (2022-2026) and future activities with the intention of attracting potential collaborations to support achieving these goals. The study discusses SIOS’s present activities, including (1) capacity building e.g., webinar series, online conference, and training courses on EO and RS studies in Svalbard to train the next generation of polar scientists, (2) infrastructure development (like the current infrastructure investment programme SIOS-InfraNor) that can attract Cal/Val activities to Svalbard (3) SIOS’s airborne remote sensing activities, and (4) SIOS remote sensing service tools for field scientists. Ongoing and future activities include (1) the development of unified platform for satellite data availability for Svalbard, (2) establishing an EO and RS researcher’s forum on SIOS website, (3) community-based observations e.g. developing a citizen science project model for supporting satellite cal/val activities in Svalbard, (4) ongoing surveys on user requirements, product inventory and citizen science project, and (5) the ‘Satellite image of the week campaign’ on social media for outreach. The sustained and coordinated efforts by SIOS to develop a long-term monitoring system are expected to contribute to integrated monitoring, modelling and supporting decision making in Svalbard in the coming decades.

How to cite: Fjæraa, A. M., Jawak, S. D., Harcourt, W., Aparício, S., Pohjola, V., Andersen, B., Hübner, C., Jennings, I., Matero, I., Godøy, Ø., and Lihavainen, H.: SIOS’s Earth observation and remote sensing activities toward building an efficient regional observing system in Svalbard, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7123, https://doi.org/10.5194/egusphere-egu22-7123, 2022.

EGU22-7588 | Presentations | GI1.1

The low-power, user-configurable, digital broadband seismometer, analogue iteration: Güralp Certis

Sally Mohr, Will Reis, Rui Barbara, Marcella Cilia, Neil Watkiss, and Phil Hill

Seismic monitoring systems are continuously reducing in size and power consumption to facilitate larger scale and more remote experiments.

Güralp have been leading the way to develop a portable, user-friendly broadband seismometer that is robust, omnidirectional in its operation and maintains excellent low-noise performance. The Certimus, released in 2020, incorporates this omnidirectional sensor technology with the Minimus digitizer to provide a proven broadband station. Now, the analogue sensor component has been packaged into a robust and compact stainless-steel housing that is suitable for post-hole and surface deployments, known as the Certis.  

Certis enables users to deploy in dynamic environments, without the need for cement bases or precise levelling, as the sensor will automatically adjust to tilt up to +/- 90 degrees. Due to its small size, low weight and low power consumption, Certis significantly reduces the logistical requirements for broadband posthole deployments. In addition, the lack of levelling required allows for Certis to be easily deployed down hole without the need to manually adjust the sensor’s orientation.

Certis has a wide frequency range of 120s to 100Hz with a remote, user-selectable long period corner. The Certis design is compatible with any commercially available broadband digitizer, however increased functionality is available with the Minimus digitizer, including access to advanced state-of-health parameters.

Güralp has developed a range of accompanying accessories that expand on the functionality of Certis and Certimus. The Portable Power Module offers a compact power solution that can power offline stations for up to 6 weeks. Due to portability of both Certis and Certimus, custom-designed backpacks and smart cases allow for users to easily transport multiple systems into the field. After installation of a buried Certimus, users can easily access data from the microSD card without disturbing the sensor using a Surface Storage Module in line with the GNSS receiver.

How to cite: Mohr, S., Reis, W., Barbara, R., Cilia, M., Watkiss, N., and Hill, P.: The low-power, user-configurable, digital broadband seismometer, analogue iteration: Güralp Certis, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7588, https://doi.org/10.5194/egusphere-egu22-7588, 2022.

EGU22-9283 | Presentations | GI1.1

Performance assessment of the mobile G4301 Cavity Ring-Down Spectroscopy analyzer for atmospheric CO2, CH4 and H2O measurements

Luc Lienhardt, Olivier Laurent, and Magdalena E. G. Hofmann

Carbon dioxide (CO2) and methane (CH4) are the most important greenhouse gases, and there is an increasing need to measure these greenhouse gases with mobile measurement devices. Picarro’s G4301 Cavity Ring-Down Spectroscopy (CRDS) analyzer is a high-performance, light-weight, portable, battery-powered gas concentration analyzer that has enabled real-time measurements of CO2 and CH4 in challenging environments in the field of ecosystem [1]–[3], soil science [4] , glaciology [5], limnology [6] and indoor air quality [7]. Here we evaluate the performance of this portable greenhouse gas analyzer for atmospheric measurements, and discuss data obtained with this analyzer during balloon flights.  

The performance of the G4301 analyzer was assessed at the Metrology Laboratory (MLab) that is part of the Atmospheric Thematic Center of ICOS. The MLab regularly tests greenhouse gas analyzers that are used within the European monitoring network ICOS (Integrated Carbon Observation System). We will present CO2 and CH4 performance data on the continuous measurement repeatability (CMR), the short-term repeatability (STR), the long-term repeatability (LTR), the ambient temperature sensitivity, the inlet pressure sensitivity, and the built-in water vapor correction. We will discuss these findings in light of measurement requirements for different atmospheric applications.

To assess the performance of the analyzer in mobile field measurements, the G4301 was deployed at several balloon flights over Paris.

 

References

[1]         J. H. Matthes, A. K. Lang, F. V. Jevon, and S. J. Russell, “Tree stress and mortality from emerald ash borer does not systematically alter short-term soil carbon flux in a mixed northeastern U.S. forest,” Forests, vol. 9, no. 1, pp. 1–16, 2018.

[2]         L. Kohl et al., “Technical note: Interferences of volatile organic compounds (VOCs) on methane concentration measurements,” Biogeosciences, vol. 16, no. 17, pp. 3319–3332, 2019.

[3]         L. Jeffrey et al., “Are methane emissions from mangrove stems a cryptic carbon loss pathway? Insights from a catastrophic forest mortality,” no. June, 2019.

[4]         L. L. Chai et al., “A methane sink in the Central American high elevation páramo: Topographic, soil moisture and vegetation effects,” Geoderma, vol. 362, no. April 2019, p. 114092, 2020.

[5]         J. R. Christiansen and C. J. Jørgensen, “First observation of direct methane emission to the atmosphere from the subglacial domain of the Greenland Ice Sheet,” Sci. Rep., vol. 8, no. 1, p. 16623, Dec. 2018.

[6]         J. A. Villa et al., “Methane and nitrous oxide porewater concentrations and surface fluxes of a regulated river,” Sci. Total Environ., vol. 715, p. 136920, 2020.

[7]         Z. Merrin and P. W. Francisco, “Unburned Methane Emissions from Residential Natural Gas Appliances,” Environ. Sci. Technol., vol. 53, no. 9, pp. 5473–5482, May 2019.

How to cite: Lienhardt, L., Laurent, O., and E. G. Hofmann, M.: Performance assessment of the mobile G4301 Cavity Ring-Down Spectroscopy analyzer for atmospheric CO2, CH4 and H2O measurements, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9283, https://doi.org/10.5194/egusphere-egu22-9283, 2022.

Among new technologies that enable representation of the submarine cultural landscapes, marine geophysical surveys provide fast and cost-effective tools now widely applied to the reconnaissance and management of underwater cultural and natural resources. In addition, passive and active sensors such as LiDAR and optical one mounted on Unmanned Aircraft Systems (UAS)  represent very effective tools for coastal remote sensing applications that require high spatial resolutions. In this work we use ultra-high resolution acoustic and LiDAR-derived data to characterize and map the marine and coastal area in the Baia archeological site (Naples, Italy). This area belongs to the Campi Flegrei volcanic field, which is affected by vertical ground movement called “Bradyseism” that strongly influenced the morphology of the coast over the last 2 Ka. As a consequence, Roman artifacts and structures dating from 1st Century BC to 4st Century AC, including Villas, luxury buildings and landing ports are now below the sea water surface, and partly buried within the marine sediments. Marine geophysical investigations included ultra-high resolution swath-bathymetry and parametric sub-bottom profiler surveys that allowed to characterize and map cultural and natural resources at seabed and in the shallow subseafloor. At same time optical (both visible and multispectral) images and LiDAR-derived elevation provided detailed information of the archaeological features and their natural setting along the adjacent coast. The main aim of this approach was to implement non-destructive geophysical methods for investigating and reconstruct the interrelationships between cultural and natural heritage at sea-land interface in the Baia archeological site. Such approach is now crucial for the evaluation of future trends induced by climate change and for a number of policy and management issues.

References

Masini N., Soldovieri F. (Eds) (2017). Sensing the Past. From artifact to historical site. Series: Geotechnologies and the Environment, Vol. 16. Springer International Publishing, ISBN: 978-3-319-50516-9, doi: 10.1007/978-3-319-50518-3, pp. 575

Violante C., Gallocchio E., Pagano F. (2022) Marine archaeological investigation in the submerged Roman site of Baiae using parametric sub-bottom profiler system. Phlegrean Fields Archaeological Park (Naples, Italy). Proceedings of the 2021 IEEE International Conference on Metrology for Archaeology and Cultural Heritage. Journal of Physics Conference Series, in press.

Violante C. (2020) Acoustic remote sensing for seabed archaeology. Proceedings of the International Conference on Metrology for Archaeology and Cultural Heritage. Trento, Italy, October 22-24, 2020, 21-26. ISBN: 978-92-990084-9-2.

Violante C., (2018) A geophysical approach to the fruition and protection of underwater cultural landscapes. Examples from the Bay of Napoli, southern Italy. In: Aveta, A., Marino, B.G., Amore R. (eds.), La Baia di Napoli. Strategie per la conservazione e la fruizione del paesaggio culturale. V. 1, 66-70. Artstudiopaparo, ISBN: 978-88-99130.

How to cite: Violante, C., Masini, N., and Abate, N.: Integrated remote sensing technologies for multi-depth seabed and coastal cultural resources: the case of the submerged Roman site of Baia (Naples, Italy)., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9939, https://doi.org/10.5194/egusphere-egu22-9939, 2022.

The nature of the Estonian crust was studied using global topography, magnetic data, and gravity data to estimate its tectonic regime. The Estonian Precambrian crystalline basement, composed of Paleo- to MesoProterozoic metamorphic and igneous rocks, is covered by a Paleozoic sedimentary rock deposit 100–780 m thick. To visualize crustal sources of the Estonian basement, we employed spectrum analysis of magnetic and gravity data, as well as two-dimensional (2D) forward modeling of gravity data. The gravimetric data was also evaluated to identify the depth of the Moho and Conrad discontinuities in Estonia. The magnetic data has also been evaluated to calculate the Curie point depth, which was then utilized to predict heat flow values inside the research zone. The subsurface of Estonia is divided into six petrological-structural zones: Tallinn, Alutaguse, Johvi, West-Estonian, Tapa and South-Estonian. To assess the structural variations of the crust at these locations, profiles of topographic, gravity, magnetic and heat flow data were constructed in each of the petrological-structural zones. The spectrum analysis and 2D gravity forward models yielded residual and regional gravity anomaly maps that show a significant amplitude potential maximum across the precambrian Rapakivi granitoid plutons and the Paldiski-Pskov tectonic zone. The Curie point depth reveals values ranging from 7 to 26 km, whereas the Moho depth suggests values ranging from 48 to 72 km and the Conrad depth values ranging from 14 to 20 km.

How to cite: Solano Acosta, J. D., Hints, R., and Soesoo, A.: Insights on the tectonic styles across Estonia using satellite potential fields derived from WGM-2012 gravity data and EMAG2 magnetic data., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11398, https://doi.org/10.5194/egusphere-egu22-11398, 2022.

EGU22-12392 | Presentations | GI1.1

Semi-automatic production of highly detailed cave maps from LiDAR point clouds

Michaela Nováková, Jozef Šupinský, Ján Kaňuk, and Michal Gallay

Remote sensing technology based on laser scanning (LiDAR) has found a wide range of applications in cave mapping for a high degree of accuracy, level of detail, and time efficiency of this method. Besides the multidisciplinary research, the acquired data representing the cave morphology in a form of a dense point cloud became an essential part of the exploration for understanding the cave speleogenesis alongside capturing the current state that is of great importance in natural and cultural heritage documentation. Traditional cave cartography can benefit from using the LiDAR point clouds by a highly detailed 3D cave model enabling the creation of contours, shaded relief, or geomorphometric parameters, and a practically unlimited number of cross-sections. Compared to the passive remote sensing methods, such as photogrammetry, limited by the light conditions and cave dimensions, laser scanning is an active light-independent method that records additional attributes for each captured point in addition to its 3D coordinates. The recorded intensity of the backscattered laser pulse is very applicable for mapping purposes as it reveals spectral properties of the surface material bringing new aspects not only for the point cloud visualization but also for material differentiation, identification, and spatial localization of the cave paintings. The presented study introduces innovation in the methodology of creating a high-detail cave map from the acquired LiDAR data by combining derived cave floor model and semi-automatic procedure for identification of surface type based on the geomorphometric analysis and recorded intensity. The main benefit of the proposed approach is in the reduction of the author´s subjectivity and cave geometry generalization. By further automatization of this process, maps for large cave systems can be produced in a high level of detail.

How to cite: Nováková, M., Šupinský, J., Kaňuk, J., and Gallay, M.: Semi-automatic production of highly detailed cave maps from LiDAR point clouds, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12392, https://doi.org/10.5194/egusphere-egu22-12392, 2022.

EGU22-13132 | Presentations | GI1.1

New development of a small customizable system for the measurement of volcanic gas concentrations with LTE data transfer

Konradin Weber, Christian Fischer, and Detlef Amend

Volcanic areas frequently have diffuse gas emission of CO2, SO2, H2S and even more. Normally these diffuse emissions do not vary only by time but also with location. Therefore, the spatial variation of concentrations cannot be monitored with one measurement system alone. On the other hand, the strength of gaseous volcanic emissions is often correlated with volcanic activity and can potentially endanger population in the vicinity.

For this reason, we developed a light new low-cost unit for the parallel measurement of various gases like CO2, SO2 and H2S, which has the remarkable advantage of being able to transmit the measured data and GPS position with LTE to a remote server. Moreover, it can operate in an unattended way for days or even weeks, depending on the customizable operation modus of the unit and the capacity of the attached rechargeable battery. A solar-powered version is currently in development. The evaluation of the received data can be performed online on the server and the results are displayed continuously. The software is programmed by us in a way that alarms can be started in case that concentrations exceed predefined alarm thresholds also via email.

The electronic hardware unit is designed in a way that it can be equipped with low-cost NDIR sensors, electrochemical sensors or photoacoustic sensors (e.g. for CO2: Sensirion SCD41). There are 4 analog ports (selectable voltage or current).

The operation procedure of the sensors electronics is customizable as well: The operation can be changed from continuous running to following mode:

  • Measurement period,
  • low power sleep period,
  • sensor warm up-period,
  • measurement period etc.

The length of all these time periods of the operation procedure can be varied depending on the measurement needs. That means for long runtime of the measurement a long sleeping time between the measurement periods can be chosen. On the other hand, if low power consumption and long runtime are not necessary, short sleeping periods or even the continuous running mode can be chosen. The operation configuration, e.g. sleeping time, can be changed by remote firmware update.

How to cite: Weber, K., Fischer, C., and Amend, D.: New development of a small customizable system for the measurement of volcanic gas concentrations with LTE data transfer, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13132, https://doi.org/10.5194/egusphere-egu22-13132, 2022.

GI1.2 – Autonomous Uncrewed Aircraft Systems (UAS): Geoscience Research Platforms for the 21st century

EGU22-281 | Presentations | GI1.2

Gamma dose rate detection and mapping using a drone-mounted Safecast sensor

Hédi Katreiner, Ákos Horváth, Fanni Vörös, Márton Pál, Szabolcs Tóth, András Várhegyi, and Béla Kovács

The Structure-from-Motion (SfM) approach for developing digital elevation models and orthomosaics has been known and used in photogrammetry for several decades. Using appropriate algorithms, SfM software combines images taken from different angles and distances based on the characteristic points determined in each image. Years of practice and experience have allowed researchers to provide a solid description of the applicability and limitations of this method, but still the impact of input processing parameters in software on the quality of photogrammetric products has not been fully recognized. This study aimed to identify the most advantageous processing workflow to fill this research gap by testing 375 different setup variations in the Agisoft Metashape software for the same set of images acquired with an unmanned aerial vehicle in a proglacial area. The purpose of the experiment was to determine three workflows: 1) with the shortest calculations time; 2) as accurate as possible, regardless of the time taken for the calculations; 3) the optimum, which is a compromise between accuracy and computation time.

Each of the 375 processing setup variations was assessed based on final product accuracy, i.e., orthomosaics and digital elevation models. Three workflows were selected based on calculating the height differences between the digital elevation models and the control points that did not participate in their georeferencing. The analysis of root mean square errors (RMSE) and standard deviations indicate that excluding some of the optimization parameters during the camera optimization stage results in high RMSE and an increase in values of errors’ standard deviation. Furthermore, it has been shown that increasing the detail of individual processing steps in software does not always positively affect the accuracy of the resulting models. The experiment resulted in the development of three different workflows in the form of Python scripts for Agisoft Metashape software, which will help users to process image sets efficiently in the context of earth surface dynamics studies.

The research was funded by the National Science Center OPUS project number 2019/35/B/ST10/03928.

How to cite: Śledź, S. and Ewertowski, M.: Evaluation of the influence of Structure-from-Motion software processing parameters on the quality of digital elevation models and orthomosaics in the context of earth surface dynamics., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1375, https://doi.org/10.5194/egusphere-egu22-1375, 2022.

EGU22-1610 | Presentations | GI1.2

Study on the Influence of Slope Shape on the Development of Ephemeral Gully Based on UAV

Haiyu Wang, Guowei Pang, Chunmei Wang, Lei Wang, and Yongqing Long

In order to explore the influence of slope shape on the development of ephemeral gully, 225 ephemeral gullies were obtained by visual interpretation based on the unmanned aerial photography of Langerzigou in Jingbian County, Shaanxi Province. The number and length of ephemeral gullies, the distance from the gully head to the watershed and the gully density were calculated. The original slope DEM was obtained by interpolating the elevation points on the ephemeral gully watershed, and the DEM was used to extract the terrain curvature to describe the hillslope shape, and then analyze the relationship between the slope shape and the ephemeral gully index. The results showed that: (1) the DEM after the elevation point interpolation on the ephemeral gully watershed was used to synthesize the ephemeral gully, which can well describe the original slope topographic features before the development of the ephemeral gully. (2) From the point of view of single slope shape, the gully density of the transverse concave slope was the highest, and the number of ephemeral gullies, the average distance from the gully head to the watershed of the longitudinal concave slope were the largest. the average length of the ephemeral gully and the number of the longitudinal convex slope were the largest. From the point of view of the combined slope shape, the average length of the ephemeral gully and the average distance from the gully head to the watershed on the biconvex slope and the convex slope were larger than those on the biconvex slope and the concave-convex slope. The ephemeral gully length of double concave slope was significantly different from that of double convex slope and convex concave slope (P<0.05); The ephemeral gully length of concave convex slope was significantly different from that of double convex slope and convex concave slope (P<0.05); There was a significant difference in the distance from the trench head to the watershed between the concave convex slope and the concave convex slope (P<0.1). (3) The curvature distribution characteristics of different forms of slope shallow ditch development were analyzed.

How to cite: Wang, H., Pang, G., Wang, C., Wang, L., and Long, Y.: Study on the Influence of Slope Shape on the Development of Ephemeral Gully Based on UAV, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1610, https://doi.org/10.5194/egusphere-egu22-1610, 2022.

EGU22-5278 | Presentations | GI1.2 | Highlight

Improvements of a low-cost CO2 commercial NDIR sensor for UAV atmospheric mapping applications

Yunsong Liu, Jean-Daniel Paris, Mihalis Vrekoussis, Panayiota Antoniou, Christos Constantinides, Maximilien Desservettaz, Christos Keleshis, Olivier Laurent, Andreas Leonidou, Carole Philippon, Panagiotis Vouterakos, Pierre-Yves Quéhé, Philippe Bousquet, and Jean Sciare

Unmanned Aerial Vehicles (UAVs) have provided a cost-effective way to fill in gaps between in-situ (ground-based) and remote-sensing observations. In this study, a lightweight CO2 sensor system suitable for operations on board small UAVs has been developed and validated. The CO2 system autonomously performs in situ measurements, allowing for its integration into various platforms. It is based on a low-cost commercial nondispersive near-infrared (NDIR) CO2 sensor (Senseair AB, Sweden), with a total weight of 1058 g, including batteries. A series of accuracy and linearity tests showed that the precision is within ±1 ppm for 1σ at 1 Hz. Variability due to temperature and pressure changes was derived from environmental chamber experiments. Additionally, the system has been validated onboard a manned aircraft against a reference instrument (Picarro, USA), revealing an accuracy of ±2 ppm (1σ) at 1 Hz and ±1 ppm (1σ) at 1 min (0.02 Hz). Integration on a quad-copter led to improvements in the calibration strategy for practical applications. The developed system has been deployed in an intensive flight campaign (a total of 16 flights per day), with horizontal flights performed at a low altitude (100 m AGL). The designed system highlights the capacity to detect CO2 concentration changes at 1 Hz and spatial gradients and to provide accurate plume dispersion maps. It proved to be a good complementary measurement tool to the ground-based co-located observations performed by the Picarro G2401. This study gives a practical example of the process to be followed for the integration of a lightweight atmospheric sensor into a mobile (UAV) platform. Details of the measurement system and field implementations are described in this study to support future UAV platform applications for atmospheric trace gas measurements and closing the gaps in the monitoring of the current carbon cycle.

How to cite: Liu, Y., Paris, J.-D., Vrekoussis, M., Antoniou, P., Constantinides, C., Desservettaz, M., Keleshis, C., Laurent, O., Leonidou, A., Philippon, C., Vouterakos, P., Quéhé, P.-Y., Bousquet, P., and Sciare, J.: Improvements of a low-cost CO2 commercial NDIR sensor for UAV atmospheric mapping applications, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5278, https://doi.org/10.5194/egusphere-egu22-5278, 2022.

EGU22-5354 | Presentations | GI1.2

Chemical characterization of volcanic plumes with multifunction UAVs and extra-lightweight drones: Concepts and first applications

Niklas Karbach, Bastien Geil, Xochilt Gutiérrez, Peter Hoor, Anselm Dötterl, Nicole Bobrowski, and Thorsten Hoffmann

Investigating the chemical composition of volcanic plumes is an important method for obtaining geochemical information of volcanic systems, determining the environmental impact of volcanic outgassing and providing indications of impending activity of the volcano under investigation. However, sampling is not easy, particularly because of immediate meteorological influences on volcanic plume dispersion, but also, of course, because of potential hazards associated with sampling immediately at the rim of volcanic craters. 

When remote sensing methods are not available, UAVs offer the possibility of bringing measurement systems to the scene. Standard parameters that are commonly measured are SO2 and CO2, as well as a number of atmospheric state parameters such as pressure, temperature, and relative humidity. In flight data transmission via radio telemetry plays a significant role, as of course both orography and current meteorology make it otherwise difficult to locate the volcanic plume from several kilometers away. In addition to key components such as SO2, CO2, and water, there are also a number of other components of interest to geoscientists, such as H2S, CO, H2, and halogen compounds. Larger drones, such as the DJI Matrice M210 or the DJI M300, can be used to fly those research based measurement systems in parallel. This allows for the chemical characterization of highly transient plume structures simultaneously at two locations or at large distances from the source including the free troposphere. Results of such measurements carried out at Mt Etna and Vulcano Island, Italy during the last two years are presented in this contribution. Larger drone systems (with the DJI Matrice M210, DJI M300) have the disadvantage that they have a comparatively high weight and therefore make it difficult to bring to the sampling site which might not be accessible by car. Smaller drones like the DJI Mavic 3 significantly reduce the weight one has to carry. In addition, the relatively high cost of the larger drone systems prevents their use for daily monitoring tasks. Therefore, we have equipped a comparatively small drone (DJI Mavic 3) with suitable radio telemetry and sensors to gather basic chemical information in volcanic plumes with an extra-lightweight system. We will introduce this new miniaturized instrumentation and present first results of measurements with the new setup.

How to cite: Karbach, N., Geil, B., Gutiérrez, X., Hoor, P., Dötterl, A., Bobrowski, N., and Hoffmann, T.: Chemical characterization of volcanic plumes with multifunction UAVs and extra-lightweight drones: Concepts and first applications, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5354, https://doi.org/10.5194/egusphere-egu22-5354, 2022.

EGU22-5661 | Presentations | GI1.2

Estimating canopy and stand structure in hybrid poplar plantations from multispectral UAV imagery

Elio Romano, Massimo Brambilla, Carlo Bisaglia, Francesca Giannetti, Clara Tattoni, Nicola Puletti, and Francesco Chianucci

Accurate estimates of canopy cover (CC),tree and stand structure are required to manage poplar plantations effectively. However, traditional measurements are limited by the cost and time-consuming nature of field methods, which inherently have limited the large scale adoption of in situ approaches. Satellite remote sensing has the advantage of broader geographical coverage, but its spatial and temporal resolution is often not suited for tree- to stand-scale applications as required in precision plantation forestry. Recently, unmanned aerial vehicles (UAVs) have become very popular in forestry. In this contribution, we tested the use of UAVs for retrieving plot-level canopy and stand attributes in hybrid poplar plantations, which were sampled in Northern Italy. A multispectral camera sensor was equipped to a multi-rotor UAV, and was used to acquire orthorectified images of 50 poplar plantations, each 0.25 ha in size, with varying age and plant density. In addition, field optical measurements of canopy structure made by digital cover photography and mensurational attributes derived from tree inventory were also performed and used as ground truth data.

The very high resolution of UAV imagery (<10 cm) allowed to efficiently perform a Simple Linear Iterative Clustering (SLIC) algorithm for superpixels generation, which was used to delineate individual poplar crowns automatically. The segmented images were then processed using Gray-Level Co-occurrence Matrices (GLCM) to calculate specific texture attributes, which were benchmarked against ground truth measurements.

Results indicated that multispectral UAVs can estimate canopy and stand structure attributes in poplar plantations reliably and accurately. Based on model performance indicators, the best model is that relating stand features to image dissimilarity. Its RMSE is in line with the standard deviations of the observed values, meaning that the error associated with the prediction is in line with the uncertainty of the calibration dataset.

The basal area, the volume of the trunk and the crown volume were the most correlated attributes with image dissimilarity valued from GLCM.By contrast, crown cover (CC) and leaf area index (LAI) were the model's attributes that could fit the worse following the clustering effect of plants’ age and the leverage occurring in some stands that results in ground truth data overestimation.

We concluded that use of UAVs can be considered an efficient tool in poplar plantation forestry. Considering the multi-scale nature of poplar plantation interventions, UAVs are particularly relevant as they can bridge between field and satellite measurements. Regarding the latter, the high resolution of UAV imagery also allows calibrating metrics from coarser scale satellite products, avoiding or reducing the need for field calibration efforts.

How to cite: Romano, E., Brambilla, M., Bisaglia, C., Giannetti, F., Tattoni, C., Puletti, N., and Chianucci, F.: Estimating canopy and stand structure in hybrid poplar plantations from multispectral UAV imagery, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5661, https://doi.org/10.5194/egusphere-egu22-5661, 2022.

EGU22-10511 | Presentations | GI1.2 | Highlight

UAV-based precision mapping techniques for disease and pest identification

Abraham Mejia-Aguilar, Dana Barthel, Ekaterina Chuprikova, Ben Alexander McLeod, Massimiliano Trenti, Christine Kerschbamer, Ulrich Prechsl, and Katrin Janik

Mountain agriculture is a vital social-economic activity in Europe, including the alpine Province of South Tyrol, Italy. Here, apple orchards and vineyards are extensively cultivated. Besides the difficulty to cultivate in mountain terrain (steep slopes, difficult accessibility, extreme weather conditions), the plants are exposed to a combination of biotic and abiotic stresses that can result in diseases caused by pathogens. It results in the loss of the yield and quality of products, economic losses, reducing food security with severe ecological impacts, and affects many ecosystem services (such as agrotourism).

This work presents a proximal sensing technique based on an unmanned aerial platform with a payload consisting of multi and hyperspectral optical cameras. Such platforms are suitable to access rugged terrains in a short time to map the presence of diseases and pests, as well they provide imagery for the optimal management of farms. We study three different experiments: apple orchard, vineyard, and forestry, observing Apple proliferation, Flavescence dorée, and Pine processionary, respectively. We aim at a non-invasive and non-destructive method to monitor plant diseases in the direction of high-precision mapping agriculture applications by exploring supervised classification methods based on ground data to distinguish healthy and unhealthy trees.

How to cite: Mejia-Aguilar, A., Barthel, D., Chuprikova, E., McLeod, B. A., Trenti, M., Kerschbamer, C., Prechsl, U., and Janik, K.: UAV-based precision mapping techniques for disease and pest identification, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10511, https://doi.org/10.5194/egusphere-egu22-10511, 2022.

EGU22-11912 | Presentations | GI1.2

Discovery and characterization of environmental hazards by means of dynamic coordination of drones driven by satellite detection maps

Luca Cicala, Donato Amitrano, Angelino Cesario Vincenzo, Francesco Gargiulo, Gabriella Gigante, Francesco Nebula, Roberto Palumbo, Sara Parrilli, Domenico Pascarella, and Francesco Tufano

In some environmental applications, satellite acquisitions could not be able to provide all the information necessary to characterize the problem at hand due, for example, to limited spatial resolution or inadequate revisit time. However, in these cases, they can be used for preliminary investigation of the area of interest with the purpose to guide subsequent acquisitions with higher spatial resolution made by means of aerial sensing. This work presents an innovative application combining both satellite acquisitions and aerial close-range sensing implemented via drones in autonomous and coordinated flight. The case study concerns the discovery of illegal micro-dumps and other environmental hazards in Campania Region (Italy). The envisioned workflow includes the detection of target environmental criticalities in very high-resolution optical satellite images and a methodology to plan and adaptively re-plan a survey mission of a team of drones aimed at confirming the presence of a micro-dump and at its characterization. The processing of satellite images is validated on real data in a significative application context, while the performance of the acquisition strategy performed by the drone team are characterized trough simulations on a pre-analysed geographical area.

How to cite: Cicala, L., Amitrano, D., Cesario Vincenzo, A., Gargiulo, F., Gigante, G., Nebula, F., Palumbo, R., Parrilli, S., Pascarella, D., and Tufano, F.: Discovery and characterization of environmental hazards by means of dynamic coordination of drones driven by satellite detection maps, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11912, https://doi.org/10.5194/egusphere-egu22-11912, 2022.

EGU22-12130 | Presentations | GI1.2

Concept for open-path gas measurements between a drone and a base station

Tim Dunker, Asbjørn Berge, Karl H. Haugholt, Richard J. D. Moore, and Håvard Tørring

We present a platform for open-path tunable diode laser absorption spectroscopy between a drone and a base station. This is a step towards an open-path measurement between two collaborating drones, which to our knowledge has not yet been achieved. Such a system enables mapping of remote (permafrost tundra, e.g.) or hazardous areas (landfills, e.g.) and localization of emissions. We use a commercially available quad-copter drone that carries a reflector and a LED for being tracked. The base station consists of a self-made pan-tilt unit that carries a camera to track the drone, and the optical measurement system. The base station is controlled through a field--programmable gate array. We decided to built the base station ourselves to ensure a fast response, enabling tracking of the drone. To demonstrate the concept, our tunable diode laser absorption setup is tailored towards the detection of ammonia (NH3) because of its fairly strong absorption, and thus comparatively easy detectability. The distributed feedback laser operates at a centre wavelength of 1512 nm, with a bandwidth of approximately 2 nm (full width at half maximum), and a typical output power of 10 mW. We characterize the stability of the drone, the reflector, and the laser system. We aim to further develop this concept such that it (a) can be implemented on two collaborating drones, without the need for a base station, and (b) to measure other greenhouse gases or pollutants, such as methane or hydrogen sulphide.

How to cite: Dunker, T., Berge, A., Haugholt, K. H., Moore, R. J. D., and Tørring, H.: Concept for open-path gas measurements between a drone and a base station, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12130, https://doi.org/10.5194/egusphere-egu22-12130, 2022.

GI2.2 – Data fusion, integration, correlation and advances of non-destructive testing methods and numerical developments for engineering and geosciences applications

EGU22-5731 | Presentations | GI2.2

Ultrasonic Scattering and Absorption Imaging for the Reinforced Concrete using Adjoint Envelope Tomography

Tuo Zhang, Christoph Sens-Schönfelder, Niklas Epple, and Ernst Niederleithinger

Seismic and ultrasound tomography can provide rich information about spatial variations of elastic properties inside a material rendering this method ideal for non-destructive testing. These tomographic methods primarily use direct and reflected waves, but are also strongly affected by waves scattering at small-scale structures below the resolution limit. As a consequence, conventional tomography has the ability to unveil the deterministic large-scale structure only, rendering scattered waves imaging noise. To image scattering and absorption properties, we presented the adjoint envelope tomography (AET) method that is based on a forward simulation of wave envelopes using Radiative Transfer Theory and an adjoint (backward) simulation of the envelope misfit, in full analogy to full-waveform inversion (FWI). In this algorithm, the forward problem is solved by modelling the 2-D multiple nonisotropic scattering in an acoustic medium with spatially variable heterogeneity and attenuation using the Monte-Carlo method. The fluctuation strength ε and intrinsic quality factor Q-1 in the random medium are used to describe the spatial variability of scattering and absorption, respectively. The misfit function is defined as the differences between the full squared observed and modelled envelopes. We derive the sensitivity kernels corresponding to this misfit function that is minimized during the iterative adjoint inversion with the L-BFGS method. This algorithm has been applied in some numerical tests (Zhang et al., 2021). In the present work, we show real data results from an ultrasonic experiment conducted in a reinforced concrete specimen. The later coda waves of the envelope processed from the 60 KHz ultrasonic signal are individually used for intrinsic attenuation inversion whose distribution has similarity to the temperature distribution of the concrete block. Based on the inversion result of intrinsic attenuation, scattering strength is inverted from early coda waves separately, which successfully provides the structure of the small-scale heterogeneity in the material. The resolution test shows that we recover the distribution of heterogeneity reasonably well.

How to cite: Zhang, T., Sens-Schönfelder, C., Epple, N., and Niederleithinger, E.: Ultrasonic Scattering and Absorption Imaging for the Reinforced Concrete using Adjoint Envelope Tomography, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5731, https://doi.org/10.5194/egusphere-egu22-5731, 2022.

EGU22-13401 | Presentations | GI2.2

Tunnel deformation rate analysis based on PS-InSAR technique and stress-area method  

Long Chai, Xiongyao Xie, Pan Li, Biao Zhou, and Li Zeng

The permanent scatterer synthetic aperture radar interferometry (PS-InSAR) technique can detect the permanent scatterers(PSs) on the ground. But the deformation of PSs can’t be used to analyze the deformation of underground buildings below the ground surface directly, such as tunnels. In this paper, the process of tunnel deformation analysis using PSs data and stress-area method is proposed. The deformation data of PSs are used to fit the surface deformation of tunnel by kriging interpolation method. The stress area method is used to calculate the deformation of the soil above the tunnel, then the deformation of tunnel can be acquired. This process was applied to calculate the deformation of a tunnel in Shanghai, China. The results show that the fitted surface deformation rate data are accurate, with the maximum absolute difference of 1.45mm/y and the minimum difference of 0.11mm/y compared with the level monitoring data. The tunnel deformation rate calculated by this process is close to the measured deformation rate of the tunnel with error level in millimeters. The surface and tunnel deformation rate curves are similar in the tunnel extension direction. PS-InSAR technique has the advantages of acquiring large area, historical data of surface deformation. Combined with the process proposed in this paper, Large-scale tunnel deformation analysis can be achieved.

How to cite: Chai, L., Xie, X., Li, P., Zhou, B., and Zeng, L.: Tunnel deformation rate analysis based on PS-InSAR technique and stress-area method  , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13401, https://doi.org/10.5194/egusphere-egu22-13401, 2022.

EGU22-2341 | Presentations | GI2.2 | Highlight

Monitoring of Bridges by Satellite Remote Sensing Using Multi-Source and Multi-Resolution Data Integration Techniques: a Case Study of the Rochester Bridge

Valerio Gagliardi, Luca Bianchini Ciampoli, Fabrizio D’Amico, Maria Libera Battagliere, Sue Threader, Amir M. Alani, Andrea Benedetto, and Fabio Tosti

Monitoring of bridges and viaducts has become a priority for asset owners due to progressive infrastructure ageing and its impact on safety and management costs. Advancement in data processing and interpretation methods and the accessibility of Synthetic Aperture Radar (SAR) datasets from different satellite missions have contributed to raise interest for use of near-real-time bridge assessment methods. In this context, the Multi-temporal Interferometric Synthetic Aperture Radar (MT-InSAR) space-borne monitoring technique has proven to be effective for detection of cumulative surface displacements with a millimetre accuracy [1-3].

This research aims to investigate the viability of using satellite remote sensing for structural assessment of the Rochester Bridge in Rochester, Kent, UK. To this purpose, high-resolution SAR datasets are used as the reference information and complemented by additional data from different sensing technologies (e.g., medium-resolution SAR datasets and ground-based (GB) non-destructive testing (NDT)). In detail, high-resolution SAR products of the COSMO-SkyMed (CSK) mission (2017-2019) provided by the Italian Space Agency (ASI) in the framework of the Project “Motib - ID 742”, approved by ASI, are processed using a MT-InSAR approach.

The method allowed to identify several Persistent Scatterers (PSs) – which have been associated to different structural elements (e.g., the bridges piers) over the four main bridge decks – and monitor bridge displacements during the observation time. The outcomes of this study demonstrate that information from the use of high-resolution InSAR data can be successfully integrated to datasets of different resolution, scale and source technology. Compared to stand-alone technologies, a main advantage of the proposed approach is in the provision of a fully-comprehensive (i.e., surface and subsurface) and dense array of information with a larger spatial coverage and a higher time acquisition frequency. This results in a more effective identification and monitoring of decays at reduced costs, paving the way for implementation into next generation Bridge Management Systems (BMSs).

Acknowledgements: This research is supported by the Italian Ministry of Education, University and Research under the National Project “EXTRA TN”, PRIN2017, Prot. 20179BP4SM. Funding from MIUR, in the frame of the“Departments of Excellence Initiative 2018–2022”,attributed to the Department of Engineering of Roma Tre University, is acknowledged.Authors would also like to acknowledge the Rochester Bridge Trust for supporting research discussed in this paper. The COSMO-SkyMed (CSK) products - ©ASI- are provided by the Italian Space Agency (ASI) under a license to use in the framework of the Project “ASI Open-Call - Motib (ID 742)” approved by ASI.

References

[1] Gagliardi V., Bianchini Ciampoli L., D'Amico F., Alani A. M., Tosti F., Battagliere M. L., Benedetto A., “Bridge monitoring and assessment by high-resolution satellite remote sensing technologies”, Proc. SPIE 11525, SPIE Future Sensing Technologies. 2020. doi: 1117/12.2579700

[2] Jung, J.; Kim, D.-j.; Palanisamy Vadivel, S.K.; Yun, S.-H. "Long-Term Deflection Monitoring for Bridges Using X and C-Band Time-Series SAR Interferometry". Remote Sens. 2019

[3] Gagliardi V., Bianchini Ciampoli L., D'Amico F., Tosti F., Alani A. and Benedetto A. “A Novel Geo-Statistical Approach for Transport Infrastructure Network Monitoring by Persistent Scatterer Interferometry (PSI)”. In: 2020 IEEE Radar Conference, Florence, Italy, 2020, pp. 1-6, doi: 10.1109/RadarConf2043947.2020.9266336

How to cite: Gagliardi, V., Bianchini Ciampoli, L., D’Amico, F., Battagliere, M. L., Threader, S., Alani, A. M., Benedetto, A., and Tosti, F.: Monitoring of Bridges by Satellite Remote Sensing Using Multi-Source and Multi-Resolution Data Integration Techniques: a Case Study of the Rochester Bridge, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2341, https://doi.org/10.5194/egusphere-egu22-2341, 2022.

The need to monitor and evaluate the impact of natural phenomena on structures, infrastructures, as well as on the natural environment, in recent years, plays a role of considerable importance for society also due to the continuous occurrence of "catastrophic events" which recently faster change our Planet.

Innovation and research have allowed a profound change in the data acquisition and acquisitions methodology coming to develop increasingly complex and innovative technologies. From an application point of view, remote sensing gives the possibility to easily manage the layer information which is indispensable for the best characterization of the environment from a numerical and a chemical-physical point of view.

NeMeA Sistemi srl, observant to the environment and its protection for years, began to study it using RADAR / SAR (Synthetic Aperture RADAR) data thanks to the opportunity to use in the best way the COSMO-SkyMed data through the tender Open Call for SMEs (Small and Medium Enterprises) of the Italian Space Agency in 2015.

Since then, NeMeA Sistemi srl has started a highly focused and innovative training that led us to observe the Earth in a new way. The path undertaken in NeMeA Sistemi srl is constantly growing and allowed us to know the RADAR / SAR data and the enormous potential.

The COSMO-SkyMed data provided is treated, processed and transformed by providing various information, allows you to identify changes, classify objects and artifacts measuring them.

In this context, NeMeA Sistemi srl in 2016 proposed a first project for the monitoring of illegal buildings in the Municipality of Ventimiglia (Liguria), with positive results. In this context, the final product was obtained with classic standard classification techniques of the SAR data.

 Following this positive experience, NeMeA Sistemi srl applied also to the regional call issued by Sardegna Ricerche for the Sardinia Region where the source of funding is the European Regional Development Fund (ERDF) 2014-2020.

The SardOS project (Sardinia Observed from Space), proposed by NeMeA Sistemi srl, aims to monitor and safeguard environmental and anthropogenic health in the territory of 4 Sardinian municipalities (Alghero, Capoterra, Quartu and Arzachena), also identifying the coast profiles, the evolutionary trend of sediments in the riverbed and buildings not present in the land registry. For environmental monitoring purposes, COSMO-SkyMed data are exploited and combined with bathymetric measurements acquired using the Hydra aquatic drone owned by NeMeA Sistemi srl. SAR data were processed using innovative specific territorial analysis algorithms in urban environment.

After these successful cases studies, which allowed the development of new services for the territorial monitoring and control, NeMeA Sistemi srl is working on a new project, 3xA (Creation of Machine Learning and Deep Learning algorithms dedicated to pattern recognition in SAR data). By exploiting Artificial Intelligence, the implemented algorithms use innovative unsupervised techniques to identify any changes.

The objective of this document is to provide an overview of the experience gained in NeMeA Sistemi srl, the value-added products and innovative services developed in the company aimed at environmental monitoring, the prevention of dangers and natural risks.

How to cite: Pennino, I.: A strategy of territorial control: from the standard comparison techniques to the Advanced Unsupervised Deep Learning Change Detection in high resolution SAR images, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3799, https://doi.org/10.5194/egusphere-egu22-3799, 2022.

EGU22-12743 | Presentations | GI2.2

Integrating Remote Sensing data to assess the protective effect of forests on rockfall:The case study of Monte San Liberatore (Campania, Italy)

Alessandro Di Benedetto, Antonella Ambrosino, and Margherita Fiani

In recent years, great interest has been paid to the risk that hydrogeological instability causes to the territory, especially in densely populated and geologically fragile areas. 
The forests, exerting a natural restraint, play an important protective function for the infrastructures and settlements underneath from the danger of falling rocks that fall from the rocky walls. This protective action is influenced not only by issues related to the vegetation itself but also by the morphology of the terrain, as a steeply sloping land surface can significantly increase the momentum of the rolling rock.
The aim of our work is to design a methodology based on the integration of remote sensing data, in detail optical satellite images and LiDAR data acquired by UAVs, to identify areas most prone to natural rockfall retention [1]. The results could then be used to identify areas that need to be reinforced artificially (rockfall nets) and naturally (protective forests).
The test area is located near Monte San Liberatore in the Campania region (Italy), which was affected in 1954 by a disastrous flood, in which heavy rains induced the triggering of a few complex landslides in a region that was almost geomorphologically susceptible.  Indeed, there are several areas subject to high risk of rockfalls, whose exposed value is represented by a complex infrastructural network of viaducts, tunnels, and galleries along the north-west slope of the mountain, which is partly covered by thick vegetation, which reduces the rolling velocity of rocks detaching from the ridge. 
According to the Carta della Natura, the vegetation most present in the area is the holm oak (Quercus Ilex), an evergreen, long-lived, medium-sized tree. Its taproot makes it resistant and stable, able to survive in extremely severe environments such as rocky soils or vertical walls, so it is ideal for slope protection.
The first processing step involved the multispectral analysis on Pleiades 1A four-band (RGB +NIR) high-resolution satellite images (HRSI). The computed vegetation indices (NDVI, RVI and NDWI) were used to assess the vegetation health status and its presumed age; thus, the most resilient areas of the natural compartment in terms of robustness and vigor were identified. The average plant height was determined using the normalized digital surface model (nDSM).
Next, starting from the Digital Terrain Model (DTM), we derived the morphometric features suitable for the description of the slope dynamics: slope gradient, exposure with respect to the North direction, plane, and convexity profile. The DTM and the DSM were created by interpolating on a grid the LiDAR point cloud acquired via UAV. Classification of areas having similar characteristics was made using SOM (Self-Organizing Maps), based on unsupervised learning.
The classified maps obtained delimit the similar areas from a morphological and vegetation point of view; in this way, all those areas that tend to have a higher propensity for rock roll reduction were identified.

[1] Fanos, Ali Mutar, and Biswajeet Pradhan. "Laser scanning systems and techniques in rockfall source identification and risk assessment: a critical review." Earth Systems and Environment 2.2 (2018): 163-182.

How to cite: Di Benedetto, A., Ambrosino, A., and Fiani, M.: Integrating Remote Sensing data to assess the protective effect of forests on rockfall:The case study of Monte San Liberatore (Campania, Italy), EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12743, https://doi.org/10.5194/egusphere-egu22-12743, 2022.

EGU22-6251 | Presentations | GI2.2

Algorithms fusion for near-surface geophysical survey

Yih Jeng, Chih-Sung Chen, and Hung-Ming Yu

The near-surface geophysical methods have been widely applied to investigations of shallow targets for scientific and engineering research. Various data processing algorithms are available to help visualize targets, data interpretation, and finally, achieve research goals.

Most of the available algorithms are Fourier-based with linear stationary assumptions. However, the real data are rarely the case and should be treated as nonlinear and non-stationary. In recent decades, a few newer algorithms are proposed for processing non-stationary, or nonlinear and non-stationary data, for instance, wavelet transform, curvelet transform, full-waveform inversion, Hilbert-Huang transform, etc. This progress is encouraging, but conventional algorithms still have many advantages, like strong theoretical bases, fast, and easy to apply, which the newer algorithms are short of.

In this study, we try to fuse both conventional and contemporary algorithms in near-surface geophysical methods. A cost-effective ground-penetrating radar (GPR) data processing scheme is introduced in shallow depth structure mapping as an example. The method integrates a nonlinear filtering technique, natural logarithmic transformed ensemble empirical mode decomposition (NLT EEMD), with the conventional pseudo-3D GPR data processing methods including background removal and migration to map the subsurface targets in 2D profile. The finalized pseudo-3D data volume is constructed by conventional linear interpolation. This study shows that the proposed technique could be successfully employed to locate the buried targets with minimal survey effort and affordable computation cost. Furthermore, the application of the proposed method is not limited to GPR data processing, any geophysical/engineering data with the similar data structure are applicable.

How to cite: Jeng, Y., Chen, C.-S., and Yu, H.-M.: Algorithms fusion for near-surface geophysical survey, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6251, https://doi.org/10.5194/egusphere-egu22-6251, 2022.

EGU22-2533 | Presentations | GI2.2

Monitoring of Airport Runways by Satellite-based Remote Sensing Techniques: a Geostatistical Analysis on Sentinel 1 SAR Data

Valerio Gagliardi, Sebastiano Trevisani, Luca Bianchini Ciampoli, Fabrizio D’Amico, Amir M. Alani, Andrea Benedetto, and Fabio Tosti

Maintenance of airport runways is crucial to comply with strict safety requirements for airport operations and air traffic management [1]. Therefore, monitoring pavement surface defects and irregularities with a high temporal frequency, accuracy and spatial density of information becomes strategic in airport asset management [2-3]. In this context, Multi-Temporal Interferometric Synthetic Aperture Radar (MT-InSAR) techniques are gaining momentum in the assessment and health monitoring of infrastructure assets, proving their viability for the long-term evaluation of ground scatterers. However, the implementation of C-band SAR data as a routine tool in Airport Pavement Management Systems (APMSs) for the accurate measurement of differential displacements on runways is still an open challenge [4]. This research aims to demonstrate the viability of using medium-resolution (C-band) SAR products and their contribution to improve current maintenance strategies in case of localised foundation settlements in airport runways. To this purpose, Sentinel-1A SAR products, available through the European Space Agency (ESA) Copernicus Program, were acquired and processed to monitor displacements on “Runway n.3” of the “L. Da Vinci International Airport” in Fiumicino, Rome, Italy.A geostatistical study is performed for exploring the spatial data structure and for the interpolation of the Sentinel-1A SAR data in correspondence of ground control points.The analysis provided ample information on the spatial continuity of the Sentinel 1 data, also in comparison with the high-resolution COSMO-SkyMed and the ground-based topographic levelling data, taken as the benchmark.Furthermore, a comparison between the MT-InSAR outcomes from the Sentinel-1A SAR data, interpolated by means of Ordinary Kriging, and the ground-truth topographic levelling data demonstrated the accuracy of the Sentinel 1 data. Results support the effectiveness of using medium-resolution InSAR data as a continuous and long-term routine monitoring tool for millimetre-scale displacements in airport runways. Outcomes of this study can pave the way for the development of more efficient and sustainable maintenance strategies for inclusion in next-generation APMSs.  

Acknowledgments and fundings: The authors acknowledge the European Space Agency (ESA), for providing the Sentinel 1 SAR products for the development of this research. The COSMO-SkyMed Products—©ASI (Italian Space Agency)- are delivered by ASI under the license to use.This research falls within the National Project “EXTRA TN”, PRIN 2017, supported by MIUR. The authors acknowledge funding from the MIUR, in the frame of the “Departments of Excellence Initiative 2018–2022”, attributed to the Department of Engineering of Roma Tre University

 References

[1]Gagliardi V., Bianchini Ciampoli L., D'Amico F., Tosti F., Alani A. and Benedetto A. “A Novel Geo-Statistical Approach for Transport Infrastructure Network Monitoring by Persistent Scatterer Interferometry (PSI)”. In: 2020 IEEE Radar Conference, Florence, Italy, 2020, pp. 1-6

[2]Gagliardi V, Bianchini Ciampoli L, Trevisani S, D’Amico F, Alani AM, Benedetto A, Tosti F. "Testing Sentinel-1 SAR Interferometry Data for Airport Runway Monitoring: A Geostatistical Analysis". 2021; 21(17):5769. https://doi.org/10.3390/s21175769

[3]Gao, M.; Gong, H.; Chen, B.; Zhou, C.; Chen, W.; Liang, Y.; Shi, M.; Si, Y. "InSAR time-series investigation of long-term ground displacement at Beijing Capital International Airport, China". Tectonophysics 2016, 691, 271–281.

[4]Department of Transportation Federal Aviation Administration (FAA), Advisory Circular 150/5320-6F, Airport Pavement Design and Evaluation, 2016

How to cite: Gagliardi, V., Trevisani, S., Bianchini Ciampoli, L., D’Amico, F., Alani, A. M., Benedetto, A., and Tosti, F.: Monitoring of Airport Runways by Satellite-based Remote Sensing Techniques: a Geostatistical Analysis on Sentinel 1 SAR Data, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2533, https://doi.org/10.5194/egusphere-egu22-2533, 2022.

EGU22-7009 | Presentations | GI2.2

Geoelectric data modeling using Mimetic Finite Difference Method

Deepak Suryavanshi and Rahul Dehiya

Nondestructive imaging and monitoring of the earth's subsurface using the geoelectric method require reliable and versatile numerical techniques for solving differential equation that govern the method's physic. The discrete operator should encompass fundamental properties of the original continuum model and differential operator for a robust numerical algorithm. In geoelectric modeling, critical model properties are anisotropy, irregular geometry, and discontinuous physical properties, whereas vital continuum operator properties are symmetry, the positivity of solutions, duality, and self-adjointness of differential operators and exact mathematical identities of the vector and tensor calculus. In this study, to simulate the response, we use the Mimetic Finite Difference Method (MFDM), where the discrete operator is constructed based on the support operator [1]. The MFDM operator mimics the properties mentioned above for structured and unstructured grids [2]. It is achieved by enforcing the integral identities of the continuum divergence and gradient operator to satisfy the integral identities by discrete analogs. 

The developed algorithm's accuracy is benchmarked using the analytical responses of dyke models of various conductivity contrasts for pole-pole configuration. After verifying the accuracy of the scheme, further tests are conducted to check the robustness of the algorithm involving the non-orthogonality of the grids, which is essential for simulating response for rugged topography. The surface potential is simulated using structured grids for a three-layer model. Subsequently, the orthogonal girds are distorted using pseudo-random numbers, which follow a uniform distribution. To quantify the distortion, we calculated the angles at all grid nodes. The node angles emulate a Gaussian distribution. We characterize those grids as highly distorted, for which the angle at the grid node is outside 20 to 160 degrees interval. The numerical tests are conducted by varying degrees of grid distortion, such that the highly distorted cells are from 1% to 10% of the total cells. The maximum error in surface potential stays below 1.5% in all cases. Hence, the algorithm is very stable with grid distortion and consequently can model the response of a very complex model. Thus, the developed algorithm can be used to analyze geoelectrical data of complex geological scenarios such as rugged topography and anisotropic subsurface. 

[1] Winters, Andrew R., and Mikhail J. Shashkov. Support Operators Method for the Diffusion Equation in Multiple Materials. No. LA-UR-12-24117. Los Alamos National Lab.(LANL), Los Alamos, NM (United States), 2012.

[2] Lipnikov, Konstantin, Gianmarco Manzini, and Mikhail Shashkov. "Mimetic finite difference method." Journal of Computational Physics 257 (2014): 1163-1227.

How to cite: Suryavanshi, D. and Dehiya, R.: Geoelectric data modeling using Mimetic Finite Difference Method, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7009, https://doi.org/10.5194/egusphere-egu22-7009, 2022.

EGU22-8712 | Presentations | GI2.2

Estimation of point spread function for unmixing geological spectral mixtures

Maitreya Mohan Sahoo, Arun Pattathal Vijayakumar, Ittai Herrmann, Shibu K. Mathew, and Alok Porwal

Geological materials are mixtures of different endmember constituents with most of them having particles smaller in size than the path length of incident light. The obtained spectral response (reflectance) from such mixtures is nonlinear which can be attributed to multiple scattering of light and the receiver sensor’s height from the incident surface. Assuming a sensor’s fixed instantaneous field of view (IFOV), variation in its field of view (FOV) by shifting its height affects the spatial resolution of acquired spectra. We propose to estimate the point spread function (PSF) for which the spectral responses of fine-resolution pixels acquired by a sensor are mixed to produce a coarse-resolution pixel obtained by the same. Our approach is based on the sensor’s unchanged IFOV obtaining spectral information from a smaller ground resolution cell (GRC) at a lower FOV and a larger GRC with an increased sensor’s FOV. The larger GRC producing a coarse resolution pixel can be modeled as a gaussian PSF of its corresponding center and neighboring fine-resolution subpixels with the center exerting the maximum influence. Extensive experiments performed using a point-based sensor and a push broom scanner revealed such variational effects in PSF that are dependent on the sensor’s FOV, the spatial interval of acquisition, and optical properties. The coarse-resolution pixels’ spectra were regressed with their corresponding fine-resolution subpixels to provide estimates of the PSF values that assumed the shape of a two-dimensional Gaussian function. Constraining these values as sum-to-one introduced sparsity and explained variability in the spectral acquisition by different sensors.  The estimated PSFs were further validated through the linear spectral unmixing technique. It was observed that the fractional abundances obtained for the fine-resolution subpixels convolved with our estimated PSF to produce its corresponding coarse-resolution counterpart with minimal error. The obtained PSFs using different sensors also explained spectral mixing at different scales of observation and provided a basis for nonlinear unmixing integrating spatial as well as spectral effects and addressing endmember variability. We performed our experiments with various coarse-grained and fine-grained igneous and sedimentary rocks under laboratory conditions to validate our results which were compared with available literature. 

How to cite: Sahoo, M. M., Pattathal Vijayakumar, A., Herrmann, I., Mathew, S. K., and Porwal, A.: Estimation of point spread function for unmixing geological spectral mixtures, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8712, https://doi.org/10.5194/egusphere-egu22-8712, 2022.

EGU22-9441 | Presentations | GI2.2

Water use efficiency (WUE) Modeling at Leaf level of Cotton (Gossypium hirsutum L.) in Telangana, India

Shreedevi Moharana and Phanindra BVN Kambhammettu

Water use efficiency (WUE) plays a vital role in planning and management of irrigation strategies. Considering the spatial scale, WUE can be quantified at scales ranging from leaf to whole-plant to ecosystem to region. However, the inter-relation and their associate is poorly understood. This study is aimed at stimulating WUE of irrigated cotton at leaf () and further investigate the role of environmental and biophysical conditions on WUE dynamics. This study was conducted in an agricultural croplands located in Sangareddy district, about 70 km west of Hyderabad, the capital city of southern state Telangana, India. Ground based observation were made such as soil moisture, photosynthetic parameters and meteorological parameters. Modelling leaf water use efficiency has been established. The stomatal conductance  and  of cotton leaves exposed to ambient CO2 were simulated using Ball-Berry (mBB) model. Moreover, the stomatal conductance  and  of Cotton leaves exposed to ambient CO2 is simulated using modified Ball-Berry model, with instantaneous gas exchanges measured around noon used to parameterize and validate the model. We observed a large diurnal (4.3±1.9 mmolCO2 mol-1H2O) and seasonal (5.16±1.51 mmolCO2 mol-1H2O) variations in  during the crop period. Model simulated  and  are in agreement with the measurements (R2>0.5, RMSE<0.3). Our results conclude that WUE is ruled by climatic as well as vegetative factors respectively, and are largely controlled by changes in transpiration over photosynthesis. This needs further investigation with extensive analysis by building library of in-situ measurements.

 

Keywords: Cotton, WUE, Irrigation, Stomatal conductance, Ball Berry Model

How to cite: Moharana, S. and Kambhammettu, P. B.: Water use efficiency (WUE) Modeling at Leaf level of Cotton (Gossypium hirsutum L.) in Telangana, India, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9441, https://doi.org/10.5194/egusphere-egu22-9441, 2022.

EGU22-4826 | Presentations | GI2.2

A 24 GHz MIMO radar for the autonomous navigation of unmanned surface vehicles

Giovanni Ludeno, Gianluca Gennarelli, Carlo Noviello, Giuseppe Esposito, Ilaria Catapano, and Francesco Soldovieri

In the last years, unmanned surface vehicles (USVs) in marine environment have attracted considerable interest since they are flexible observation platforms suitable to operate in remote areas on demand. Accordingly, their usage has been proposed in several contexts such as research activities, military operations, environmental monitoring and oil exploration [1]. However, most of current USV remote control techniques are based on human-assisted technology thus a fully autonomous USV system is still an open issue [2].

The safety of the vehicle and the ability to complete the mission depends crucially on the capability of detecting objects on the sea surface, which is necessary for collision avoidance. Anti-collision systems for USVs typically require measurements collected from multiple sensors (e.g. Lidar, cameras, etc.), where each sensor has its own advantages and disadvantages in terms of resolution, field of view (FoV), operative range and so on [3].

Among the available sensing technologies, radar is capable of operating regardless of weather and visibility conditions, has moderate costs and can be easily adapted to operate within the marine environment. Furthermore, radar is characterized by an excellent coverage and high resolution along the range coordinate and it is also able to guarantee a 360° FoV in the horizontal plane.

Nautical radars are the most popular solutions to detect floating targets on the sea surface; however, they are bulky and not always effective in detecting small objects located very close to the radar.

This contribution investigates the applicability of a compact and lightweight 24 GHz multiple-input multiple-output (MIMO) radar originally developed for automotive applications to localize floating targets at short ranges (from tens to few hundreds of meters). In this frame, we propose an ad-hoc signal processing strategy combining MIMO technology, detection, and tracking algorithms to achieve target localization and tracking in a real-time mode. A validation of the proposed signal processing chain is firstly performed thanks to numerical simulations. After, preliminary field tests carried out in the marine environment are presented to assess the performance of the radar prototype and of the related signal processing.

 

References

  • [1] Zhixiang et al. "Unmanned surface vehicles: An overview of developments and challenges", Annual Reviews in Control, vol. 41, pp. 71-93, 2016
  • [2] Caccia, M. Bibuli, R. Bono, G. Bruzzone, “Basic navigation, guidance and control of an unmanned surface vehicle”, Autonomous Robots, vol. 25, no. 4, pp. 349-365, 2008
  • [3] Robinette, M. Sacarny, M. DeFilippo, M. Novitzky, M. R. Benjamin, “Sensor evaluation for autonomous surface vehicles in inland waterways”, Proc. IEEE OCEANS 2019, pp. 1-8, 2019.

How to cite: Ludeno, G., Gennarelli, G., Noviello, C., Esposito, G., Catapano, I., and Soldovieri, F.: A 24 GHz MIMO radar for the autonomous navigation of unmanned surface vehicles, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4826, https://doi.org/10.5194/egusphere-egu22-4826, 2022.

Road pavements play a crucial role in the development of any construction as they provide safe surface on which vehicles can travel comfortably [1]. Pavements are multi-layered structures of processed and compacted materials in different thicknesses and in both unbound and bound forms with the function of supporting vehicle loads as well as providing a smooth riding quality. The condition of road pavement structures is susceptible to the impact of uncertain environmental factors and traffic loads, resulting in pavement deterioration over time. Therefore, the mechanical properties of pavements (such as strength, stiffness, etc.) need to be monitored on a regular basis to make sure that the pavement condition meets its prescribed threshold. The ground-penetrating radar (GPR) and deflection-based methods (e.g., the falling weight deflectometer (FWD)) are the most popular non-destructive testing (NDT) methods in pavement engineering science that are often used in combination to evaluate the damage and strength of pavements [2-4]. The layer thickness data from GPR scans are used as an input for deflection-based measurements to back-calculate the elastic moduli of the layers [2]. During the recent years, problems concerning the automatic interpretation of data from NDTs have received good attention and have simulated peer to peer interests in many industries like transportation. The use of Artificial Intelligence (AI) and Machine Learning (ML) techniques for the interpretation of NDT data can offer many advantages such as the improved speed and accuracy of analysis, especially for large-volume datasets. This study aims to train a dataset collected from GPR (2 GHz horn antenna) and the Curviameter deflection-based equipment using AI and ML algorithms to classify road flexible pavements based on their mechanical properties. Curviameter data are used as ground-truth measurements of pavement stiffness, whereas the GPR data provide geometric and physical attributes of the pavement structure. Several methods such as support vector machine (SVM), artificial neural network (ANN), and k nearest neighbours (KNN) are proposed and their performance in terms of accuracy of estimation of the strength and deformation properties of pavement layers are compared with each other as well as with the classical statistical methods. The results of this study can help road maintenance officials to identify and prioritise pavements at risk and make cost-effective and informed decisions for maintenance.

References

[1] Tosti, F., Bianchini Ciampoli, L., D’Amico, F. and Alani, A.M. (2019). Advances in the prediction of the bearing capacity of road flexible pavements using GPR. In: 10th International Workshop on Advanced GPR, European Association of Geoscientists & Engineers, pages 1-5.

[2] Plati, C., Loizos, A. & Gkyrtis, K. Assessment of Modern Roadways Using Non-destructive Geophysical Surveying Techniques. Surv Geophys 41, 395–430 (2020). 

[3] A. Benedetto, F. Tosti, Inferring bearing ratio of unbound materials from dielectric properties using GPR, in: Proceedings of the 2013 Airfield and Highway Pavement Conference: Sustainable and Efficient Pavements, June 2013, pp. 1336–1347.

[4] Tosti, F., Bianchini Ciampoli, L., D’Amico, F., Alani, A.M., Benedetto, A. (2018). An experimental-based model for the assessment of the mechanical properties of road pavements using GPR. Construction and Building Materials, Volume 165, pp. 966-974.

How to cite: Dinmohammadi, F., Bianchini Ciampoli, L., Tosti, F., Benedetto, A., and Alani, A. M.: On the use of Artificial Intelligence for classification of road pavements based on mechanical properties using ground-penetrating radar and deflection-based non-destructive testing data, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1849, https://doi.org/10.5194/egusphere-egu22-1849, 2022.

EGU22-74 | Presentations | GI2.2

Experimental assessment of corrosion influence in reinforced concrete by GPR 

Salih Artagan, Vladislav Borecky, Özgür Yurdakul, and Miroslav Luňák

Corrosion is one of the most critical issues leading to damage in reinforced concrete structures. In most cases, the detection of corrosion damage is performed by visual inspection. Other techniques (drilling cores with petrography or chemical examination, potential measurements, and resistivity measurements) require minimum destruction since they can be utilized by reaching the reinforcement bar [1]. Recently, there has been an increasing trend to use Ground Penetrating Radar (GPR) as one of the emerging non-destructive testing (NDT) techniques in the diagnosis of corrosion [2].

This paper focuses on a series of GPR tests on specimens constructed from poor-quality concrete and plain round bar. These specimens were subjected to accelerated corrosion tests under laboratory conditions. The corrosion intensity of those specimens is non-destructively assessed with GPR, by collecting data before and after corrosion tests. For GPR tests, the IDS Aladdin system was used with a double polarized 2 GHz antenna. Based on GPR measurement, Relative Dielectric Permittivity (RDP) values of concrete, are calculated based on the known dimension of specimens and two-way travel time (twt) values obtained from A-scans. The change in RDP values of specimens before and after exposure to corrosion is then computed. Moreover, amplitude change and variation in frequency spectrum before and after corrosion exposure are analyzed.

The results of this experimental study thus indicate that corrosion damage in reinforced concrete can be determined by using several GPR signal attributes. More laboratory tests are required for better quantification of the impact of the corrosion phenomenon in reinforced concrete.

All GPR tests were conducted in Educational and Research Centre in Transport; Faculty of Transport Engineering; University of Pardubice. This work is supported by the University of Pardubice (Project No: CZ.02.2.69/0.0/0.0/18_053/0016969).

[1]        V. Sossa, V. Pérez-Gracia, R. González-Drigo, M. A. Rasol, Lab Non Destructive Test to Analyze the Effect of Corrosion on Ground Penetrating Radar Scans, Remote Sensing. 11 (2019) 2814. https://doi.org/10.3390/rs11232814.

[2]        K. Tešić, A. Baričević, M. Serdar, Non-Destructive Corrosion Inspection of Reinforced Concrete Using Ground-Penetrating Radar: A Review, Materials. 14 (2021) 975. https://doi.org/10.3390/ma14040975.

How to cite: Artagan, S., Borecky, V., Yurdakul, Ö., and Luňák, M.: Experimental assessment of corrosion influence in reinforced concrete by GPR , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-74, https://doi.org/10.5194/egusphere-egu22-74, 2022.

EGU22-13515 | Presentations | GI2.2

Application of ground penetrating radar (GPR) in look-ahead detection of slurry balance shield machine

Weiwei Duan, Xiongyao Xie, Yong Yang, Kun Zeng, Huiming Wu, Li Zeng, and Kang Li

The shield machine has become the mainstream of subway tunnels construction because of its safety and efficiency. But with the continuous development of urban construction, the environment of subway tunnel construction is becoming more and more complex. In the process of shield tunnels construction in southern cities of China, slurry balance shield machines often encounter various obstacles, such as large diameter boulders and concrete pile foundations, which result in accidents of shield machine sticking. Therefore, it is necessary to quickly and accurately detect the distribution of obstacles in front of shield excavation face in advance so that operators can in time take measures to reduce the occurrence of such accidents. Ground penetrating radar (GPR) is a method widely used in engineering geological exploration. It has advantages of small working space, high efficiency and no damage compared with other detecting methods. When the GPR antenna is mounted on the cutter head of the shield machine, the obstacles in the stratum ahead of the shield machine can be detected in real time. Under this condition the GPR antenna’s real work mode is that it will rotate with the cutter head to form a circumferential survey line. Based on Finite-Difference-Time-Domain-Method (FDTD), authors use the common numerical simulation software (GPRMAX) to make simulations of GPR circumferential detection under the antenna array rotating with the cutter head, which verifies the theoretical feasibility of this method. By simulating radar emission and reflection pattern of electromagnetic wave, we study the propagation pattern of the reflect wave after encountering the obstacles and conclude the image pattern to establish the foundation for image recognition of obstacles. Due to the radar wave being susceptible to electromagnetic interference, GPR is still lack of engineering practice in shield advanced detection. To reduce the interference of the surrounding metal cutter head, a new strip radar antenna with a shielding shutter is designed to improve the directivity of electromagnetic wave propagation. Several antennas are fixed at several slurry openings of the cutter head of slurry balance shield machine to form radar antenna array and improve detection efficiency and accuracy.

How to cite: Duan, W., Xie, X., Yang, Y., Zeng, K., Wu, H., Zeng, L., and Li, K.: Application of ground penetrating radar (GPR) in look-ahead detection of slurry balance shield machine, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13515, https://doi.org/10.5194/egusphere-egu22-13515, 2022.

EGU22-6168 | Presentations | GI2.2

An investigation into road trees’ root systems through geostatistical analysis of GPR data

Livia Lantini, Sebastiano Trevisani, Valerio Gagliardi, Fabio Tosti, and Amir M. Alani

Street trees are a critical asset for the urban environment due to the variety of environmental and social benefits provided [1]. However, the conflicting coexistence of tree root systems with the built environment, especially with road infrastructure, frequently results in extensive damage, such as the uplifting and cracking of sidewalks and curbs, endangering pedestrians, cyclists, and road drivers’ safety.

Within this context, ground penetrating radar (GPR) is gaining recognition as an accurate non-destructive testing (NDT) method for tree roots’ assessment and mapping [2]. Nevertheless, the investigation methods developed so far are often inadequate for application on street trees, as these are often difficult to access. Recent studies have focused on implementing new survey and processing techniques for rapid tree root assessment based on combined time-frequency analyses of GPR data [3].  

This research also explores the adoption of a geostatistical approach for the spatial data analysis and interpolation of GPR data. The radial development of roots and the complexity of root network constitute a challenging setting for the spatial data analysis and the recognition of specific spatial features.

Preliminary results are therefore presented based on a geostatistical analysis of GPR data. To this end, 2-D GPR outputs (i.e., B-scans and C-scans) were analysed to quantify the spatial correlation amongst radar amplitude reflection features and their anisotropy, leading to a more reliable detection and mapping of tree roots. The proposed processing system could be employed for investigating trees difficult to access, such as road trees, where more comprehensive analyses are difficult to implement. Results' interpretation has shown the viability of the proposed analysis and will pave the way to further investigations.

 

Acknowledgements

The authors would like to express their sincere thanks and gratitude to the following trusts, charities, organisations and individuals for their generosity in supporting this project: Lord Faringdon Charitable Trust, The Schroder Foundation, Cazenove Charitable Trust, Ernest Cook Trust, Sir Henry Keswick, Ian Bond, P. F. Charitable Trust, Prospect Investment Management Limited, The Adrian Swire Charitable Trust, The John Swire 1989 Charitable Trust, The Sackler Trust, The Tanlaw Foundation, and The Wyfold Charitable Trust.

 

References

[1]         Tyrväinen, L., Pauleit, S., Seeland, K., & de Vries, S., 2005. "Benefits and uses of urban forests and trees". In: Urban Forests and Trees. Springer, Berlin, Heidelberg.

[2]         Lantini, L., Tosti, F., Giannakis, I., Zou, L., Benedetto, A. and Alani, A. M., 2020. "An Enhanced Data Processing Framework for Mapping Tree Root Systems Using Ground Penetrating Radar," Remote Sensing 12(20), 3417.

[3]         Lantini, L., Tosti, F., Zou, L., Ciampoli, L. B., & Alani, A. M., 2021. "Advances in the use of the Short-Time Fourier Transform for assessing urban trees’ root systems." Earth Resources and Environmental Remote Sensing/GIS Applications XII. Vol. 11863. SPIE, 2021.

How to cite: Lantini, L., Trevisani, S., Gagliardi, V., Tosti, F., and Alani, A. M.: An investigation into road trees’ root systems through geostatistical analysis of GPR data, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6168, https://doi.org/10.5194/egusphere-egu22-6168, 2022.

EGU22-13441 | Presentations | GI2.2

Collaborative use of ground monitoring and GPR data for the control of ground settlement in shield tunnel in soft soil

Kang Li, Xiongyao Xie, Xiaobin Zhang, Biao Zhou, Tenfei Qu, and Li Zeng

In recent years, China's construction demand for shield tunnel in soft soil continues to increase, and the control of ground settlement in tunnel boring process affects the safety of the tunnel itself and its superstructure directly. Paying close attention to controlling the strata loss and the ground settlement by multiple means is important to ensure construction safety. In this paper, the intelligent real-time monitoring system with dual-frequency ground penetrating radar (GPR) is used to detect the quality of back-fill grouting of shield tunnel, while monitoring points are arranged on the ground surface to acquire the settlement values in real time. The collaborative analysis of ground and underground monitoring results reveals the relationship between grouting and settlement values, and realizes the dynamic guidance on grouting operation, which helps to achieve the purpose of controlling ground settlement better. Last but not least, this paper proposes an outlook on a multiple-data fusion system based on cloud computing platform to adapt to more complex and multiple data in the future, so as to achieve the higher accuracy, efficiency and intelligence of monitoring data analysis.

How to cite: Li, K., Xie, X., Zhang, X., Zhou, B., Qu, T., and Zeng, L.: Collaborative use of ground monitoring and GPR data for the control of ground settlement in shield tunnel in soft soil, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13441, https://doi.org/10.5194/egusphere-egu22-13441, 2022.

EGU22-2166 | Presentations | GI2.2

Attenuation-compensated reverse-time migration of waterborne GPR based on attenuation coefficient estimation

Ruiqing Shen, Yonghui Zhao, Hui Cheng, and Shuangcheng Ge

To the waterborne ground-penetrating radar detection, reverse-time migration (RTM) method can image the structure of the bottom of the water and locate the buried bodies. However, the image quality is limited by the attenuation of electromagnetic waves. How to compensate the attenuation becomes a critical problem. Some RTM methods related to the attenuation-compensated have been developed in recent years. We use the attenuation-compensated RTM based on the minus conductivity. However, the method is limited by the estimation of the attenuation coefficient. Here, we propose an attenuation-coefficient estimation method based on the centroid frequency downshift method (CFDS). In EM attenuation tomography, the centroid frequency downshift method works for attenuation estimation. Compared with the CFDS method in tomography, our proposal is based on the centroid frequency of the bottom-interface of water instead of the source wavelet. Thus, we can avoid the problem of the unknown source wavelet. The method is based on two assumptions: 1) GPR data can be regarded as zero-offset records. 2) Reflections from underwater interfaces are independent of frequency. In addition, the formula about the attenuation coefficient shows when the ratio between the conductivity and the product of the dielectric constant and the angular frequency is greater than one, the attenuation coefficient tends to be a constant. This does not meet the assumption that the attenuation coefficient is linearly related to frequency. We will select a proper frequency range to meet the linear relation by the spectral ratio method. Because the ratio of the signal spectrum of the bottom interface to the spectrum of the underwater interface is consistent with the change of the attenuation coefficient with frequency. Then, the CFDS method will acquire a linear attenuation coefficient with the frequency. Finally, we choose half of the central frequency to acquire the estimated attenuation coefficient. We design a layered waterborne GPR detection model, the conductivity of the silt layer varies between 0.1 and 0.01. The error of the conductivity estimation is below 10%. After acquiring the attenuation coefficient, the attenuation-compensated RTM works correctly and effectively.

How to cite: Shen, R., Zhao, Y., Cheng, H., and Ge, S.: Attenuation-compensated reverse-time migration of waterborne GPR based on attenuation coefficient estimation, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2166, https://doi.org/10.5194/egusphere-egu22-2166, 2022.

EGU22-4914 | Presentations | GI2.2

Sensing roadway surfaces for a non-destructive assessment of pavement damage potential

Konstantinos Gkyrtis, Andreas Loizos, and Christina Plati

Modern roadways provide road users with both a comfortable and safe ride to their destinations. Increases in traffic demands and maximum allowable loads imply that roadway authorities should also care for the structural soundness of pavements. In parallel, budgetary limitations and frequent road closures for rehabilitation activities, especially in heavy-duty motorways, might guide the related authorities to focus their strategies on the preservation of pavements functional performance. However, structural issues concerning pavement damage remain on the forefront, as pavement’s service life extends beyond its design life; thus structural condition assessment is required to ensure pavement sustainability in the long-term.

 

Non-Destructive Testing (NDT) has played a major role during condition monitoring and evaluation of rehabilitation needs. Together with input from visual inspections and/or sample destructive testing (e.g. coring), NDT data help to define indicators and threshold values that assist the related decision-making for pavement condition assessment. The most indicative tool for structural evaluation is the Falling Weight Deflectometer (FWD) that senses roadway surfaces through geophones recording load-induced deflections at various locations. Additional geophysical inspection data with the Ground Penetrating Radar (GRP) is used to estimate pavement’s stratigraphy. Integrating the above sensing data enables the estimation of pavement’s performance and its damage potential.

 

To this end, a major challenge that pavement engineers face, concerns the assumptions made about the mechanical characterization of pavement materials. Asphalt mixtures, located on the upper pavement layers, behave in a viscoelastic mode because of temperature- and loading frequency- dependency, whereas in the contrary, simplified assumptions for linear elastic materials are most commonly made during the conventional NDT analysis. In this research, an integration of mainly NDT data and sample data from cores extracted in-situ is followed to comparatively estimate the long-term pavement performance through internationally calibrated damage models considering different assumptions for asphalt materials. Two damage modes are considered including bottom-up and top-down fatigue cracks that are conceptually perceived as alligator cracks and longitudinal cracks respectively alongside a roadway’s surface. As part of an ongoing research for the long-term pavement condition monitoring, data from a new pavement was considered at this stage indicating a promising capability of NDT data towards damage assessment.

 

Overall, this study aims to demonstrate the power of pavement sensing data towards structural health monitoring of roadways pinpointing the significance of database development for a rational management throughout a roadway’s service life. Furthermore, data from limited destructive testing enriches the pavement evaluation processes with purely mechanistic perspectives thereby paving the way for developing integrated protocols with improved accuracy for site investigations, especially at project-level analysis, where rehabilitation design becomes critical.

How to cite: Gkyrtis, K., Loizos, A., and Plati, C.: Sensing roadway surfaces for a non-destructive assessment of pavement damage potential, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4914, https://doi.org/10.5194/egusphere-egu22-4914, 2022.

EGU22-1544 | Presentations | GI2.2

Dielectric Constant Estimation through Alpha Angle with a Polarimetric GPR System

Lilong Zou, Fabio Tosti, and Amir M. Alani

As a recognised non-destructive testing (NDT) tool, Ground Penetrating Radar (GPR) is becoming increasingly common in the field of environmental engineering [1]-[3]. GPR uses electromagnetic (EM) waves which travel at specific velocity determined by the permittivity of the material. With the development of new GPR signal processing methodologies, finding information on the physical properties of hidden targets has become a key target. Currently, only three types of approach could be applied for the quantitative estimation of permittivity from GPR data, i.e., hyperbola curve fitting, common middle point (CMP) velocity analysis and full-waveform inversion. However, the main challenges for the estimation of permittivity from GPR backscattered signals are to provide effective and accurate strategy for prediction.

In this research, we used a dual-polarimetric GPR system to estimate the dielectric constant of targets. The system is equipped with two 2GHz antennas polarised perpendicularly each to one another (HH and VV). The dual polarisation enables deeper surveying, providing images of both shallow and deeper subsurface features. Polarimetry is a property of EM waves that generally refers to the orientation of the electric field vector, which plays here an important role as it allows either direct or parameterisation permittivity effects within the scattering problem in the remote sensing [4].

The aim of this research is to provide a novel and more robust approach for dielectric constant prediction using a dual-polarimetric GPR system. To this extent, the relationship between the relative permittivity and the polarimetric alpha angle have been investigated based on data collected by a GPR system with dual-polarised antennas. The approach was then assessed by laboratory experiments where different moisture sand targets (simulating the effect of different relative permittivity targets) were measured. After signal processing, a clear relationship between the alpha angle and the relative permittivity was obtained, proving the viability of the proposed method.

 

Acknowledgements

The authors would like to express their sincere thanks and gratitude to the following trusts, charities, organisations and individuals for their generosity in supporting this project: Lord Faringdon Charitable Trust, The Schroder Foundation, Cazenove Charitable Trust, Ernest Cook Trust, Sir Henry Keswick, Ian Bond, P. F. Charitable Trust, Prospect Investment Management Limited, The Adrian Swire Charitable Trust, The John Swire 1989 Charitable Trust, The Sackler Trust, The Tanlaw Foundation, and The Wyfold Charitable Trust.

 

References

[1] Zou, L. et al., 2020. Mapping and Assessment of Tree Roots using Ground Penetrating Radar with Low-Cost GPS. Remote Sensing, vol.12, no.8, pp:1300.

[2] Zou, L. et al., 2020. On the Use of Lateral Wave for the Interlayer Debonding Detecting in an Asphalt Airport Pavement Using a Multistatic GPR System. IEEE Transactions on Geoscience and Remote Sensing, vol. 58, no. 6, pp. 4215-4224.

[3] Zou, L. et al., 2021. Study on Wavelet Entropy for Airport Pavement Debonded Layer Inspection by using a Multi-Static GPR System. Geophysics, vol. 86, no. 3, pp. WB69-WB78.

[4] J. Lee and E. Pottier, Polarimetric Imaging: From Basics to Applications, FL, Boca Raton: CRC Press, 2009.

How to cite: Zou, L., Tosti, F., and Alani, A. M.: Dielectric Constant Estimation through Alpha Angle with a Polarimetric GPR System, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1544, https://doi.org/10.5194/egusphere-egu22-1544, 2022.

EGU22-4912 | Presentations | GI2.2

Multiples suppression scheme of waterborne GPR data

Yonghui Zhao, Ruiqing Shen, and Hui Cheng

Ground penetrating radar (GPR) is a geophysical method that uses high frequency electromagnetic waves to detect underground or internal structures of objects. It has been widely used in the Geo-engineering and environment detection. In recent years, GPR has played an increasingly important role in shallow underwater structure survey due to its advantages of economy, high efficiency and high accuracy. However, due to the strong reflection coefficients of water surface and bottom for electromagnetic waves, there are multiples in the GPR profile acquired in waters, which will reduce the signal-to-noise ratio of the data and even lead to false imaging, finally seriously affect the reliability of the interpretation result. With the increasing requirement of high-precise GPR detection in waters, multiple suppression has become an essential issue in expanding the application fields of GPR. In order to suppress multiple waves in waterborne GPR profile, a novel multiple wave suppression method based on the combination scheme of the predictive deconvolution and free surface multiple wave suppression (SRME). Based on the validity test of one-dimensional data, the adaptive optimizations of these two methods are carried out according to the characteristics of GPR data in waters. First, the prediction step of predictive deconvolution can be determined by picking up the bottom reflection signal. Second, the water layer information provided by the bottom reflection is used in continuation from the surface to the bottom to suppress the internal multiples. The numerical model and real data test results show that each single method can suppress most of the multiples of the bottom interface and the combination strategy can further remove the additional residues. The research provides a basis for the precise interpretation of GPR data in hydro-detection.

How to cite: Zhao, Y., Shen, R., and Cheng, H.: Multiples suppression scheme of waterborne GPR data, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4912, https://doi.org/10.5194/egusphere-egu22-4912, 2022.

EGU22-8594 | Presentations | GI2.2

Analysis of low-frequency drone-borne GPR for soil surface electrical conductivity mapping

Kaijun Wu and Sébastien Lambot

In the VHF frequencies, the sensitivity of the reflection coefficient at the air-soil interface with respect to the soil electromagnetic properties, i.e., the dielectric permittivity and electrical conductivity, varies with frequency. The lower the frequency is, the lower the sensitivity to permittivity is and the larger the sensitivity to conductivity is. In this study, we investigated low-frequency drone-borne ground-penetrating radar (GPR) and full-wave inversion for soil surface electrical conductivity characterization. In order to have a good sensitivity to electrical conductivity, we operated in the 15-45 MHz frequency range. We conducted both numerical and field experiments, under the assumptions that the soil magnetic permeability is equal to the magnetic permeability of free space, and that the soil permittivity and conductivity are frequency-independent. Through the numerical experiments, we analyzed the sensitivity of the soil permittivity and electrical conductivity by plotting the objective function in the inverse problem. In addition, we analyzed the effects of modelling errors on the retrieval of the permittivity and conductivity. The results show that the soil electrical conductivity is sensitive enough to be characterized by the low-frequency drone-borne GPR. The depth of sensitivity was found to be around 0.5-1 m in the 15-45 MHz frequency range. Yet, the effects of permittivity cannot be neglected totally, especially for relatively wet soils. For validating our approach, we conducted field measurements with the drone-borne GPR and we compared results with electromagnetic induction (EMI) measurements considering two different offsets, i.e., 0.5 and 1 m, respectively. The lightweight GPR system consists of a handheld vector network analyzer (VNA), a 5-meter half-wave dipole antenna, a micro-computer stick, a GPS receiver, and a power bank. The good agreement in terms of absolute values and field structures between the GPR and EMI maps demonstrated the feasibility of the proposed low-frequency drone-borne GPR method, which appears thereby to be promising for precision agriculture applications.

How to cite: Wu, K. and Lambot, S.: Analysis of low-frequency drone-borne GPR for soil surface electrical conductivity mapping, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8594, https://doi.org/10.5194/egusphere-egu22-8594, 2022.

EGU22-4437 | Presentations | GI2.2

Rebar corrosion monitoring with a multisensor non-destructive geophysical techniques.

Enzo Rizzo, Giacomo Fornasari, Luigi Capozzoli, Gregory De Martino, and Valeria Giampaolo

Rebar Corrosion is one of the main causes of deterioration of engineering reinforced structure. This degradation reduces the service life and durability of the structures. Such degradation can result in the collapse of engineering structures. When the first cracks are noticed on the concrete surface, corrosion has generally reached an advanced stage and maintenance action is required. The early detection of rebar corrosion of bridges, tunnel, buildings and other civil engineering structures is important to reduce the expensive cost to repair the deteriorated structure. Several techniques have been developed for understanding the mechanism and kinetics of the corrosion of rebar, but the paper defines the interest of combining several NDT for field inspection to overcome the limitation of measuring instantaneous corrosion rates and to improve the estimation of the service life of RC structures. Non-destructive testing and evaluation of the rebar corrosion is a major issue for predicting the service life of reinforced concrete structures.

This paper introduces a laboratory test, that was performed at Geophysical Laboratory of Ferrara University. The test consisted in a multisensor application concerning rebar corrosion monitoring using different geophysical methods on a concrete sample of about 50 x 30 cm with one steel rebar of 10 mm diameter. An accelerating reinforcement bar corrosion using direct current (DC) power supply with 5% sodium chloride (NaCl) solution was used to induce rebar corrosion. The 2GHz GPR antenna by IDS, the ERT with Abem Terrameter and Self-Potential with Keithley multivoltmeter at high impedance were used for rebar corrosion monitoring. A multisensor approach should reduce the errors resulting from measurements, and improve synergistically the estimation of service life of the RC.

Each technique provided specific information, but a data integration method used in the operating system will further improve the overall quality of diagnosis. The collected data were used for an integration approach to obtain an evolution of the phenomenon of corrosion of the reinforcement bar. All the three methods were able to detect the physical parameter variation during the corrosion phenomena, but more attention is necessary on natural corrosion, that is a slow process and the properties of the experimental steel–concrete interface may not be representative of natural corrosion. However, each of these geophysical methods possesses certain advantages and limitations, therefore a combination of these geophysical techniques, with an multisensor approach is recommended to use to obtain the corrosion condition of steel and the condition of concrete cover.  Moreover, extrapolating laboratory results performed with a single rebar to a large structure with interconnected rebars thus remains challenging. Therefore, during the next experiments, special care must be taken regarding the design and preparation of the samples to obtain meaningful information for field application.

How to cite: Rizzo, E., Fornasari, G., Capozzoli, L., De Martino, G., and Giampaolo, V.: Rebar corrosion monitoring with a multisensor non-destructive geophysical techniques., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4437, https://doi.org/10.5194/egusphere-egu22-4437, 2022.

EGU22-2712 | Presentations | GI2.2

Quality assessment in railway ballast by integration of NDT methods and remote sensing techniques: a study case in Salerno, Southern Italy

Luca Bianchini Ciampoli, Valerio Gagliardi, Fabrizio D'Amico, Chiara Clementini, Daniele Latini, and Andrea Benedetto

Maintenance and rehabilitation policies represent a task of paramount importance for managers and administrators of railway networks to maintain the highest standards of transport safety while limiting as much as possible the costs of maintenance operations.

To this effect, high-productivity survey methods become crucial as they allow for timely recognition of the quality of the asset elements, among which the ballast layers are the most likely to undergo rapid deterioration processes. Particularly, Ground Penetrating Radar (GPR) has received positive feedback from researchers and professionals due to the capability of detecting signs of deterioration within ballasted trackbeds that are not recognizable by a visual inspection at the surface, through high-productivity surveys. On the other hand, satellite-based surveys are nowadays being increasingly applied to the monitoring of transport assets. Techniques such as Multi-temporal Interferometric Synthetic Aperture Radar (MT-InSAR) allows evaluating potential deformations suffered by railway sections and their surroundings by analyzing phase changes between multiple images of the same area acquired at progressive times. 

For both of these techniques, despite the wide recognition by the field-related scientific literature, survey protocols and data processing standards for the detection and classification of the quality of ballast layers are still missing. In addition, procedures of integration and data fusion between GPR and InSAR datasets are still very rare.

The present study aims at demonstrating the viability of the integration between these two survey methodologies for a more comprehensive assessment of the condition of ballasted track-beds over a railway stretch. Particularly, a traditional railway section going from Cava de’ Tirreni to Salerno, Campania (Italy), was subject to both GPR and MT-InSAR inspections. An ad hoc experimental setup was realized to fix horn antennas with different central frequencies to an actual inspection convoy that surveyed the railway stretch in both the travel directions. Time-frequency methods were applied to the data to detect subsections of the railway affected by the poor quality of ballast (i.e. high rate of fouling). In parallel, a two-years MT-InSAR analysis was conducted to evaluate possible deformations that occurred to the railway line in the period before the GPR test. In addition, results from both the analyses were compared to the reports from visual inspections as provided by the railway manager.

The results of the surveys confirm the high potential of GPR in detecting the fouling condition of the ballast layers at various stages of severity. The integration of this information to the outcomes of InSAR analysis allows for identifying whether the deterioration of the track-beds is related to poorly bearing subgrades or rather to excessive stresses between the aggregates resulting in their fragmentation.

Acknowledgments

This research is supported by the Italian Ministry of Education, University, and Research under the National Project “EXTRA TN”, PRIN2017, Prot. 20179BP4SM. Funding from MIUR, in the frame of the“Departments of Excellence Initiative 2018–2022”, attributed to the Department of Engineering of Roma Tre University, is acknowledged. The authors would also like to express their gratitude to RFI S.p.a. in the person of Eng. Pasquale Ferraro for the valuable support to the tests.

How to cite: Bianchini Ciampoli, L., Gagliardi, V., D'Amico, F., Clementini, C., Latini, D., and Benedetto, A.: Quality assessment in railway ballast by integration of NDT methods and remote sensing techniques: a study case in Salerno, Southern Italy, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2712, https://doi.org/10.5194/egusphere-egu22-2712, 2022.

EGU22-2253 | Presentations | GI2.2

An approach to integrate GPR thickness variability and roughness level into pavement performance evaluation

Christina Plati, Andreas Loizos, and Konstantina Georgouli

It is a truism that pavements deteriorate due to the combined effects of traffic loads and environmental conditions. The manner or ability of a road to meet the demands of traffic and the environment and to provide at least an acceptable level of performance to road users throughout its life is referred to as pavement performance. An important indicator of pavement performance is ride quality. This is a rather subjective measure of performance that depends on (i) the physical properties of the pavement surface, (ii) the mechanical properties of the vehicle, and (iii) the acceptance of the perceived ride quality by road users. Due to the subjectivity of ride quality assessment, many researchers have worked in the past to develop an objective indicator of pavement quality. The International Roughness Index (IRI) is considered a good indicator of pavement performance in terms of road roughness. It was developed to be linear, transferable, and stable over time and is based on the concept of a true longitudinal profile. Following the identification and quantification of ride quality by the IRI, pavement activities include the systematic collection of roughness data in the form of the IRI using advanced laser profilers, either to "accept" an as-built pavement or to monitor and evaluate the functional condition of an in-service pavement.

On the other hand, pavement performance can vary significantly due to variations in layer thickness, primarily due to the construction process and quality control methods used. Even if a uniform design thickness is specified for a road section, the actual thickness may vary. It is expected that the layer thickness will have some probability distribution, with the highest density being around the target thickness. Information on layer thickness is usually obtained from as-built records, from coring or from Ground Penetrating Radar (GPR) surveys. GPR is a powerful measurement system that provides pavement thickness estimates with excellent data coverage at travel speeds. It can significantly improve pavement structure estimates compared to data from as-built plans. In addition, GPR surveys are fast, cost effective, and non-destructive compared to coring.

The present research developed a sensing approach that extends the capability of GPR beyond its ability to estimate pavement thickness. Specifically, the approach links GPR thickness to IRI based on the principle that a GPR system and a laser profiler are independent sensors that can be combined to provide a more complete image of pavement performance. To this end, field data collected by a GPR system and a laser profiler along highway sections are analyzed to evaluate pavement performance and predict future condition. The results show that thickness variations are related to roughness levels and specify the deterioration of the pavement throughout its lifetime.

How to cite: Plati, C., Loizos, A., and Georgouli, K.: An approach to integrate GPR thickness variability and roughness level into pavement performance evaluation, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2253, https://doi.org/10.5194/egusphere-egu22-2253, 2022.

EGU22-7547 | Presentations | GI2.2

Assessing Deformation Monitoring Systems For Supporting Structural Rehabilitation under Harsh Conditions

Hans Neuner, Victoria Kostjak, Finn Linzer, Walter Loderer, Christian Seywald, Alfred Strauss, Matthias Rigler, and Markus Polt

This paper deals with the evaluation of four measuring systems for the detection of potential deformations that can occur during structural rehabilitation measures. For this purpose, a test object resembling the shape of a tunnel structure was constructed. The structural properties of this test object are discussed in the related paper by Strauss et. al submitted for the same session.

In the paper, the installed measuring systems are presented first. These are a lamella system based on fibre optics, an array of accelerometers, a digital image correlation system and a profile laser scanner based system. The operating principles of the systems are briefly introduced.

A long-term measurement on the object in an unloaded state, which extended over several weeks, enables statements about the capturing of temperature-related deformations, the temperature dependence of the measured values and drift effects of the investigated systems. Selective loading of the test object was generated via four screw rods and applied both in the elastic as well as in the plastic deformation range. This enabled knowledge gain regarding the precision and the sensitivity of the analysed measuring systems.

Environmental conditions may have a strong influence on the measurement values. The former can be determined by permanent installations on the structure and its operating conditions as well as by the undertaken rehabilitation measures. Representative for the first category we investigated the influence of magnetic fields and light conditions on the measuring systems. For the second category, strong dust formation and increased humidity were generated during a test procedure.

An assessment regarding data handling, including storage, transfer and processing, completes the investigation of the four measuring systems. A summarising evaluation concludes the article.

How to cite: Neuner, H., Kostjak, V., Linzer, F., Loderer, W., Seywald, C., Strauss, A., Rigler, M., and Polt, M.: Assessing Deformation Monitoring Systems For Supporting Structural Rehabilitation under Harsh Conditions, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7547, https://doi.org/10.5194/egusphere-egu22-7547, 2022.

EGU22-13153 | Presentations | GI2.2

Integration of multiple geoscientific investigation methods for a better understanding of a water system: the example of Chimborazo glaciers melting effects on the Chambo aquifer, Ecuador

Andrea Scozzari, Paolo Catelan, Francesco Chidichimo, Michele de Biase, Benito G. Mendoza Trujillo, Pedro A. Carrettero Poblete, and Salvatore Straface

The identification of the processes underlining natural systems often requires the adoption of multiple investigation techniques for the assessment of the sites under study. In this work, the combination of information derived from non-invasive sensing techniques, such as geophysics, remote sensing and hydrogeochemistry, highlights the possible influence of global climate change on the future water availability related to an aquifer in a peculiar glacier context, located in central Ecuador. In particular, we show that the Chambo aquifer, which supplies potable water to the region, does not contain fossil water, and it’s instead recharged over time. Indeed, the whole Chambo river basin is affected by the Chimborazo volcano, which is a glacerised mountain located in the inner tropics, one of the most critical places  to be observed in the frame of climate impact on water resources. Thanks to the infomation gathered by the various surveying techniques, numerical modelling permitted an estimate of the recharge, which can be fully originated by the runoff from Chimborazo melting glaciers. Actually, the retreat of the glaciers on top of the Chimborazo is an ongoing process presumably related to global climate change.

How to cite: Scozzari, A., Catelan, P., Chidichimo, F., de Biase, M., Mendoza Trujillo, B. G., Carrettero Poblete, P. A., and Straface, S.: Integration of multiple geoscientific investigation methods for a better understanding of a water system: the example of Chimborazo glaciers melting effects on the Chambo aquifer, Ecuador, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13153, https://doi.org/10.5194/egusphere-egu22-13153, 2022.

EGU22-8512 | Presentations | GI2.2

Verification of the performance of reinforced concrete profiles of alpine infrastructure systems assisted by innovative monitoring

Alfred Strauss, Hans Neuner, Matthias Rigler, Markus Polt, Christian Seywald, Victoria Kostjak, Finn Linzer, and Walter Loderer

The verification of the structural behaviour of existing structures and its materials characteristics requires the application of tests and monitoring to gather information about the actual response. The comparison of the actual performance and the designed performance enables the verification of the design assumptions in terms of implied loads and materials resistance. In case of non-compliance of the designed with the current performance, the design assumptions need to be updated. The objective of this contribution is to provide a guidance for the verification of the performance of reinforced concrete profiles of alpine infrastructure systems like tunnels assisted by monitoring, testing and material testing.

The application of defined loads to a structure to verify its load carrying capacity is a powerful tool for evaluating existing structures. In particular, in this research different types of load tests are employed depending on the limit state which is being investigated on tunnel profiles, on the other hand, the system responses to validate the structural performance are recorded with monitoring systems innovative in tunnel systems, such as accelerometer arrays, fibre optic sensors, laser distance sensors and digital image correlation system, see also the related paper by Neuner et. al. In these studies we also pay special attention to the capabilities of Digital Image Correlation and Nonlinear Finite Element Analysis. Digital Image Correlation (often referred to as "DIC") is an easy-to-use optical method for measuring deformations on the surface of an object. The method tracks changes in the grayscale pattern in small areas called subsets) during deformation. 

Finally, we will present the process for the implementation and validation of proof loading concepts based on the mentioned monitoring information in order to derive the existing safety level by using advanced digital twin models.  

How to cite: Strauss, A., Neuner, H., Rigler, M., Polt, M., Seywald, C., Kostjak, V., Linzer, F., and Loderer, W.: Verification of the performance of reinforced concrete profiles of alpine infrastructure systems assisted by innovative monitoring, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8512, https://doi.org/10.5194/egusphere-egu22-8512, 2022.

EGU22-9845 | Presentations | GI2.2

Implementation of an interoperable platform integrating BIM and GIS information for network-level monitoring and assessment of bridges

Luca Bertolini, Antonio Napolitano, Jhon Diezmos Manalo, Valerio Gagliardi, Luca Bianchini Ciampoli, and Fabrizio D'Amico

Monitoring of critical civil engineering infrastructures, and especially viaducts and bridges, has become a priority nowadays as the ageing of construction materials may cause damages and collapses with dramatic consequences. Following recent bridge collapses, specific guidelines on risk classification and management, safety assessment and monitoring of existing bridges have been issued in Italy, by the Minister of Infrastructure as a mandatory code [1]. Accordingly, several laws and regulations have been issued on the same topic, emphasizing the crucial role of BIM-based procedures for the design and management of civil infrastructures [2, 3]. Within this context, monitoring operations are generally conducted by on-site inspections and specialized operators, and rarely by high-frequency ground-based Non-Destructive Testing methods (NDTs). Furthermore, the implementation of satellite-based remote sensing techniques, have been increasingly and effectively used for the monitoring of bridges in the last few years [4]. Generally, these crucial pieces of information are analyzed separately, and the implementation of a multi-scale and multi-source interoperable BIM platform is still an open challenge [5].

This study aims at investigating the potential of an interoperable and upgradeable BIM platform supplemented by non-destructive survey data, such as Mobile Laser Scanner (MLS), Ground Penetrating Radar (GPR) and Satellite Remote Sensing Information (i.e. InSAR). The main goal of the research is to contribute to the state-of-the-art knowledge on BIM applications, by testing an infrastructure management platform aiming at reducing the limits typically associated to the separate observation of these assessments, to the advantage of an integrated analysis including both the design information and the routinely updated results of monitoring activities.

The activities were conducted in the framework of the Project “M.LAZIO”, approved by the Lazio Region, with the aim to develop an informative BIM platform of the investigated bridges interoperable within a Geographic Information System (GIS). As on-site surveys are carried out , a preliminary multi-source database of information  is created, to be operated as the starting point for the integration process and the development of  the infrastructure management platform. Preliminary results have shown promising viability of the data management model for supporting asset managers in the various management phases, thereby proving this methodology to be worthy for implementation in infrastructure integrated monitoring plans.

Acknowledgements

This research is supported by the Project “M.LAZIO”, accepted and funded by the Lazio Region, Italy. Funding from MIUR, in the frame of the “Departments of Excellence Initiative 2018–2022”, attributed to the Department of Engineering of Roma Tre University, is acknowledged.

References

[1] MIT, 2020. Ministero delle Infrastrutture e dei Trasporti, DM 578/2020

[2] EU, 2014. Directive 2014/24/EU of the European Parliament and of the Council of 26 February 2014 on public procurement and repealing Directive 2004/18/EC.

[3] MIMS, 2021. Ministero delle Infrastrutture e della Mobilità Sostenibile, DM 312/2021

[4] Gagliardi, V. et al., “Bridge monitoring and assessment by high-resolution satellite remote sensing technologies”. In SPIE Future Sensing Technologies; https://doi.org/10.1117/12.2579700

[5] D'Amico F. et al., "A novel BIM approach for supporting technical decision-making process in transport infrastructure management", Proc. SPIE 11863;  https://doi.org/10.1117/12.2600140

How to cite: Bertolini, L., Napolitano, A., Diezmos Manalo, J., Gagliardi, V., Bianchini Ciampoli, L., and D'Amico, F.: Implementation of an interoperable platform integrating BIM and GIS information for network-level monitoring and assessment of bridges, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9845, https://doi.org/10.5194/egusphere-egu22-9845, 2022.

Knowledge of the monument for its conservation is the result of a multidisciplinary work based on the integration of different data sources obtainable from historical research, architectural survey, the use of different imaging technologies. The latter are increasingly within the reach of conservators, architects and restoration companies thanks to the reduction of costs and to the effort to produce increasingly user-friendly imaging technologies both in terms of data acquisition and processing. The critical element is the interpretation of the results on which depends the effectiveness of these technologies in answering various questions that the restoration poses. Scientific literature suggests different approaches aimed at making the interpretation of imaging diagnostics easier, particularly by means of : i) the comparison between direct data (carrots, visual inspection) and results from non-invasive tests; ii) the use of specimens or laboratory test beds; iii) Virtual and Augmented reality (VR/AR) to be used as a work environment to facilitate the interpretation of non invasive imaging investigations. In particular, the reading and visualization of multiparametric information using VR/AR contents increases the standard modes for the transmission of knowledge of physical characteristics and state of conservation of the architectural heritage. This approach represents an effective system for storing and analysing heterogeneous data derived from a number of diverse non invasive imaging techniques, including Ground Penetrating radar (GPR) at high frequency, Infrared Thermography (IRT), Seismic tomography and other diagnostics techniques. In the context of Heritage Within Project, a VR/AR platform to interrelate heterogeneous data derived from GPR, IRT, Ultrasonic and sonic measurements along with  results finite element computations has been developed and applied to the Convent of Our Lady of Mount Carmel  in Lisbon to understand cause-and-effect mechanisms between the constructive characteristics, degradation pathologies and stress/deformation maps.

References

Gabellone F., Leucci G., Masini N., Persico R., Quarta G., Grasso F. 2013. Non-destructive prospecting and virtual reconstruction of the chapel of the Holy Spirit in Lecce, Italy. Near Surface Geophysics, doi: 10.3997/1873-0604.2012030

Gabellone F., Chiffi M., “Linguaggi digitali per la valorizzazione”, in F. Gabellone, M. T. Giannotta, M. F. Stifani, L. Donateo (a cura di), Soleto Ritrovata. Ricerche archeologiche e linguaggi digitali per la fruizione. Editrice Salentina, 2015. ISBN 978-88-98289-50-9

Masini N., Nuzzo L., Rizzo E., GPR investigations for the study and the restoration of the Rose Window of Troia Cathedral (Southern Italy), Near Surface Geophysics, 5 (5)(2007), pp. 287-300, ISSN: 1569-4445; doi: 10.3997/1873-0604.2007010 

Masini N., Soldovieri F. (Eds) (2017). Sensing the Past. From artifact to historical site. Series: Geotechnologies and the Environment, Vol. 16. Springer International Publishing, ISBN: 978-3-319-50516-9, doi: 10.1007/978-3-319-50518-3, pp. 575

Javier Ortega, Margarita González Hernández, Miguel Ángel García Izquierdo, Nicola Masini, et al. (2021). Heritage Within. European Research Project, ISBN: 978-989-54496-6-8, Braga 2021.

How to cite: Masini, N., Gabellone, F., and Ortega, J.: VR/AR based approach for the diagnosis of the state of conservation of the architectural heritage. The case of the Convento do Carmo in Lisbon, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10538, https://doi.org/10.5194/egusphere-egu22-10538, 2022.

Detecting decay in tree trunks is essential in considering tree health and safety. Continual monitoring of tree trunks is possible using a digital model, which can contain incremental assessment data on tree health. Researchers have previously employed non-destructive techniques, for instance, laser scanning, acoustics, and Ground Penetrating Radar (GPR) to study both the external and internal physical dimensions of objects and structures [1], including tree trunks [2]. Light Detection and Ranging (LiDAR) technology is also continually employed in infrastructure and asset management to generate models and to detect surface displacements with millimeter accuracy [3]. Nevertheless, the scanning of structures using these existing state-of-the-art technologies can be time consuming, technical, and expensive.

This work investigates the design and implementation of a smartphone app for scanning tree trunks to generate a 3D digital model for later visualization and assessment. The app uses LiDAR technology, which has recently become available in smart devices, for instance, the Apple iPhone 12+ and the iPad Pro. With the prevalence of internet-of-things (IoT) sensors, digital twins are being increasingly used in a variety of industries, for example, architecture and manufacturing. A digital twin is a digital representation of an existing physical object or structure. With our app, a digital twin of a tree can be developed and maintained by continually updating data on its dimensions and internal state of decay. Further, we can situate and visualize tree trunks as digital objects in the real world using augmented reality, which is also possible in modern smart devices. We previously investigated tree trunks using GPR [2] to generate tomographic maps, to denote level of decay. We aim to adopt a data integration and fusion approach, using such existing (and incremental GPR data) and an external LiDAR scan to gain a full 3D ‘picture’ of tree trunks.

We intend to validate our app against state-of-the-art techniques, i.e., laser scanning and photogrammetry. With the ability to scan tree trunks within reasonable parameters of accuracy, the app can provide a relatively low-cost environmental modelling and assessment solution for researchers and experts.

 

Acknowledgments: Sincere thanks to the following for their support: Lord Faringdon Charitable Trust, The Schroder Foundation, Cazenove Charitable Trust, Ernest Cook Trust, Sir Henry Keswick, Ian Bond, P. F. Charitable Trust, Prospect Investment Management Limited, The Adrian Swire Charitable Trust, The John Swire 1989 Charitable Trust, The Sackler Trust, The Tanlaw Foundation, and The Wyfold Charitable Trust.

 

References

[1] Alani A. et al., Non-destructive assessment of a historic masonry arch bridge using ground penetrating radar and 3D laser scanner. IMEKO International Conference on Metrology for Archaeology and Cultural Heritage Lecce, Italy, October 23-25, 2017.

[2] Tosti et al., "The Use of GPR and Microwave Tomography for the Assessment of the Internal Structure of Hollow Trees," in IEEE Transactions on Geoscience and Remote Sensing, Doi: 10.1109/TGRS.2021.3115408.

[3] Lee, J et al., Long-term displacement measurement of bridges using a LiDAR system. Struct Control Health Monit. 2019; 26:e2428.

How to cite: Uzor, S., Tosti, F., and Alani, A. M.: Low-cost scanning of tree trunks for analysis and visualization in augmented reality using smartphone LiDAR and digital twins, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3247, https://doi.org/10.5194/egusphere-egu22-3247, 2022.

EGU22-11201 | Presentations | GI2.2

DIARITSup: a framework to supervise live measurements, Digital Twins modelscomputations and predictions for structures monitoring.

Jean Dumoulin, Thibaud Toullier, Mathieu Simon, and Guillermo Andrade-Barroso

DIARITSup is a chain of various softwares following the concept of ”system of systems”. It interconnects hardware and software layers dedicated to in-situ monitoring of structures or critical components. It embeds data assimilation capabilities combined with specific Physical or Statistical models like inverse thermal and/or mechanical ones up to the predictive ones. It aims at extracting and providing key parameters of interest for decision making tools. Its framework natively integrates data collection from local sources but also from external systems [1, 2]. DIARITSup is a milestone in our roadmap for SHM Digital Twins research framework. Furthermore, it intends providing some useful information for maintenance operations not only for surveyed targets but also for deployed sensors.

Thanks to its Model-view-controller (MVC) design pattern, DIARITSup can be extended, customized and connected to existing applications. Its core component is made of a supervisor task that handles the gathering of data from local sensors and external sources like the open source meteorological data (observations and forecasts) from Météo-France Geoservice [4] for instance. Meanwhile, a recorder manage the recording of all data and metadata in the Hierarchical Data Format (HDF5) [6]. HDF5 is used to its full potential with its Single-Writer-Multiple-Readers feature that enables a graphical user interface to represent the saved data in real-time, or the live computation of SHM Digital Twins models [3] for example. Furthermore, the flexibility of HDF5 data storage allows the recording of various type of sensors such as punctual sensors or full field ones. Finally, DIARITSup is able to handle massive deployment thanks to Ansible [5] automation tool and a Gitlab synchronization for automatic updates. An overview of the developed software with a real application case will be presented. Perspectives towards improvements on the software with more component integrations (Copernicus Climate Data Store, etc.) and a more generic way to configure the acquisition and model configuration will be finally discussed.


References
[1] Nicolas Le Touz, Thibaud Toullier, and Jean Dumoulin. “Infrared thermography applied to the study of heated and solar pavement: from numerical modeling to small scale laboratory experiments”. In: SPIE - Thermosense: Thermal Infrared Applications XXXIX. Anaheim, United States, Apr. 2017. url: https://hal.inria.fr/hal-01563851.
[2] Thibaud Toullier, Jean Dumoulin, and Laurent Mevel. “Study of measurements bias due to environmental and spatial discretization in long term thermal monitoring of structures by infrared thermography”. In: QIRT 2018 - 14th Quantitative InfraRed Thermography Conference. Berlin, Germany, June 2018. url: https://hal.inria.fr/hal-01890292.
[3] Nicolas Le Touz, Thibaud Toullier, and Jean Dumoulin. “Study of an optimal heating command law for structures with non-negligible thermal inertia in varying outdoor conditions”. In: Smart Structures and Systems 27.2 (2021), pp. 379–386. doi: 10.12989/sss.2021.27.2.379. url: https://hal.inria.fr/hal-03145348.
[4] Météo France. Données publiques Météo France. 2022. url: https://donneespubliques.meteofrance.fr.
[5] Red Hat & Ansible. Ansible is Simple IT Automation. 2022. url: https://www.ansible.com/.
[6] The HDF Group. Hierarchical Data Format, version 5. 1997-2022. url: https://www.hdfgroup.org/HDF5/.

How to cite: Dumoulin, J., Toullier, T., Simon, M., and Andrade-Barroso, G.: DIARITSup: a framework to supervise live measurements, Digital Twins modelscomputations and predictions for structures monitoring., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11201, https://doi.org/10.5194/egusphere-egu22-11201, 2022.

GI2.3 – Geoscience problems related to massive release of radioactive materials by nuclear accidents and other human activities

EGU22-10713 | Presentations | GI2.3 | Highlight

Decontamination and subsequent natural restoration processes impact on terrestrial systems in Niida River Catchment in Fukushima

Yuichi Onda, Feng Bin, Yoshifumi Wakiyama, Keisuke Taniguchi, Asahi Hashimoto, and Yupan Zhang

For the Fukushima region in Japan, the large-scale decontamination in the catchments needed to require more attention because of their possible consequence in altering particulate Cs-137 flux from the terrestrial environment to the ocean. Here, combining the high-resolution satellite dataset and concurrent river monitoring results, we quantitively assess the impacts of land cover changes in large-area decontaminated regions on river suspended sediment (SS) and particulate Cs-137 dynamics during 2013-2018. We find that the decontaminated regions’ erodibility dramatically enhanced during the decontamination stage but rapidly declined in the subsequent natural-restoration stage. River SS dynamics show linear response to these land cover changes, where annual SS load (normalized by water discharge) at the end of decontamination increased by over 300% than pre-decontamination and decreased about 48% at the beginning of natural restoration. Fluctuations in particulate Cs-137 concentrations well reflect the process of sediment source alternation due to land cover changes in decontaminated regions. The “Fukushima decontamination experiment” can reveal the dramatic impact of decontamination-natural restoration processes, which highlights the need for quantitatively assessing human impacts on land use and resultant alternation in sediment transfer patterns in large scale catchments. 

How to cite: Onda, Y., Bin, F., Wakiyama, Y., Taniguchi, K., Hashimoto, A., and Zhang, Y.: Decontamination and subsequent natural restoration processes impact on terrestrial systems in Niida River Catchment in Fukushima, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10713, https://doi.org/10.5194/egusphere-egu22-10713, 2022.

EGU22-3340 | Presentations | GI2.3

Factors controlling the dissolved 137Cs seasonal fluctuations in the Abukuma River under the influence of the Fukushima Nuclear Power Plant accident 

Yasunori Igarashi, Nanb Kenji, Toshihiro Wada, Yoshifumi Wakiyama, Yuichi Onda, and Shota Moritaka

The 2011 Fukushima Daiichi Nuclear Power Plant (FDNPP) accident released large amounts of radioactive materials into the environment. River systems play an important role in the terrestrial redistribution of FDNPP-derived 137Cs in association with water and sediment movement. We examined the seasonal fluctuations in dissolved and particulate 137Cs activity concentrations and clarified the biological and physicochemical factors controlling 137Cs in the Abukuma River’s middle course in the region affected by the FDNPP accident. The results showed the water temperature and K+ concentration dominated the seasonality of the dissolved 137Cs activity concentration. We concluded that the 137Cs in organic matter is not a source of dissolved 137Cs in river water. The study also revealed the temperature dependence of Kd in riverine environments from a Van ’t Hoff equation. The standard reaction enthalpy of 137Cs in the Abukuma River was calculated to be approximately −19.3 kJ/mol. This was the first study to clearly reveal the mechanisms by which the dissolved 137Cs activity concentration and Kd are influenced by chemical and thermodynamic processes in the middle course of a large river, and it is expected to lead to an improved model of 137Cs dynamics in rivers.

How to cite: Igarashi, Y., Kenji, N., Wada, T., Wakiyama, Y., Onda, Y., and Moritaka, S.: Factors controlling the dissolved 137Cs seasonal fluctuations in the Abukuma River under the influence of the Fukushima Nuclear Power Plant accident , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3340, https://doi.org/10.5194/egusphere-egu22-3340, 2022.

EGU22-3442 | Presentations | GI2.3

A comparative study of riverine 137Cs dynamics during high-flow events at three contaminated river catchments in Fukushima

Yoshifumi Wakiyama, Takuya Niida, Hyoe Takata, Keisuke Taniguchi, Honoka Kurosawa, Kazuki Fujita, and Alexei Konoplev

This study presents the temporal variations in riverine 137Cs concentrations and fluxes to the ocean during high-flow events in three coastal river catchments contaminated by the Fukushima Daiichi Nuclear Power Plant accident. River water samples were collected at points downstream in the Niida, Ukedo, and Takase Rivers during three high-flow events that occurred in 2019–2020. Variations in both the dissolved 137Cs concentration and 137Cs concentration in suspended solids appeared to reflect the spatial pattern of the 137Cs inventory in the catchments, rather than variations in physico-chemical properties. Negative relationships between the 137Cs concentration and δ15N in suspended sediment were found in all rivers during the intense rainfall events, suggesting an increased contribution of sediment from forested areas to the elevated 137Cs concentration. The 137Cs flux ranged from 0.33 to 18 GBq, depending on the rainfall erosivity. The particulate 137Cs fluxes from the Ukedo River were relatively low compared with the other two rivers and were attributed to the effect of the Ogaki Dam reservoir upstream. The ratio of 137Cs desorbed in seawater to 137Cs in suspended solids ranged from 2.8% to 6.6% and tended to be higher with a higher fraction of exchangeable 137Cs. The estimated potential release of 137Cs from suspended solids to the ocean was 0.048–0.57 GBq, or 0.8–6.2 times higher than the direct flux of dissolved 137Cs from the river. Episodic sampling during high-flow events demonstrated that the particulate 137Cs flux depends on catchment characteristics and controls 137Cs transfer to the ocean. 

How to cite: Wakiyama, Y., Niida, T., Takata, H., Taniguchi, K., Kurosawa, H., Fujita, K., and Konoplev, A.: A comparative study of riverine 137Cs dynamics during high-flow events at three contaminated river catchments in Fukushima, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3442, https://doi.org/10.5194/egusphere-egu22-3442, 2022.

EGU22-6698 | Presentations | GI2.3

Vertical distribution of 137Cs in bottom sediments as representing the time changes of water contamination: Chernobyl and Fukushima

Aleksei Konoplev, Yoshifumi Wakiyama, Toshihiro Wada, Yasunori Igarashi, Gennady Laptev, Valentin Golosov, Maxim Ivanov, Mikhail Komissarov, and Kenji Nanba

Bottom sediments of lakes and dam reservoirs can provide an insight into understanding the dynamics of 137Cs strongly bound to sediment particles. On this premise, a number of cores of bottom sediments were collected in deep parts of lakes Glubokoe, Azbuchin, and Cooling Pond in close vicinity of the Chernobyl NPP in Ukraine, in Schekino reservoir (Upa River) in the Tula region of Russia (2018) and in Ogaki reservoir (Ukedo River) in Fukushima contaminated area (2019). Each layer of bottom sediments can be attributed to a certain time of suspended particles sedimentation. With 137Cs activity concentration in a given layer of bottom sediments corresponding to 137Cs concentration on suspended matter at that point in time, we were able to reconstruct the post-accidental dynamics of particulate 137Cs activity concentrations. Using experimental values of the distribution coefficient Kd, changes in the dissolved 137Cs activity concentrations were estimated. The annual mean particulate and dissolved 137Cs wash-off ratios were also calculated for the period after the accidents. Interestingly, the particulate 137Cs wash-off ratios for the Ukedo River at Ogaki dam were found to be similar to those for the Pripyat River at Chernobyl in the same time period after the accident, while the dissolved 137Cs wash-off ratios in the Ukedo River were an order of magnitude lower than the corresponding values in the Pripyat River. The estimates of particulate and dissolved 137Cs concentrations in Chernobyl cases were in reasonable agreement with monitoring data and predictions using the semi-empirical diffusional model. However, both the particulate and dissolved 137Cs activity concentrations and wash-off ratios in the Ukedo River declined faster during the first eight years after the FDNPP accident than predicted by the diffusional model, most likely, due to greater natural attenuation and, to some extent, remediation measures implemented on the catchments in Fukushima.

This research was supported by Science and Technology Research Partnership for Sustainable Development (SATREPS), Japan Science and Technology Agency (JST)/Japan International Cooperation Agency (JICA) (JPMJSA1603), by bilateral project No. 18-55-50002 of Russian Foundation for Basic Research (RFBR) and Japan Society for the Promotion of Science (JSPS), and JSPS Project KAKENHI (B) 18H03389.

How to cite: Konoplev, A., Wakiyama, Y., Wada, T., Igarashi, Y., Laptev, G., Golosov, V., Ivanov, M., Komissarov, M., and Nanba, K.: Vertical distribution of 137Cs in bottom sediments as representing the time changes of water contamination: Chernobyl and Fukushima, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6698, https://doi.org/10.5194/egusphere-egu22-6698, 2022.

EGU22-7068 | Presentations | GI2.3

Seasonal variation of dissolved Cs-137 concentrations in headwater catchments in Yamakiya district, Fukushima Prefecture

Taichi Kawano, Yuichi Onda, Junko Takahishi, Fumiaki Makino, and Sho Iwagami

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident occurred on March 11, 2011, and a large amount of Cs-137 was released into the environment. It is important to clarify the behavior of radioactive cesium-137 in headwater catchments because most of the Cs-137 falls and is deposited in forest areas and is transported in the environment through river systems.

The purpose of this study was to clarify the influence of water quality composition and organic matter on the seasonal variation of dissolved Cs-137 concentrations in stream water based on long-term monitoring since 2011 at four headwaters catchments in Yamakiya district, Fukushima Prefecture (Iboishiyama, Ishidairayama, Koutaishiyama, Setohachiyama), located about 35 km northwest of FDNPP.

Water temperature, pH, and EC were measured in the field, and SS and coarse organic matter were collected using a time-integrated SS (suspended sediments) sampler and organic matter net. The Cs-137 concentrations was measured in the laboratory using a germanium detector. Concentrations of cations (Na⁺,K⁺,Ca²⁺,Mg²⁺,NH₄⁺) and anions (Cl⁻,SO₄²⁻,NO₃⁻,NO₂⁻,PO₄²⁻) were measured by ion chromatography after 0.45μm filtration. In addition, dissolved organic carbon (DOC) concentrations was measured using a total organic carbon analyzer.

The results showed that K⁺, which is highly competitive with Cs-137, was detected at Iboisiyama, Ishidairayama, and Koutaishiyama, while NH₄⁺ was only detected in some samples at Iboishiyama. There was no obvious relationship between dissolved ion concentration and water temperature, and between dissolved ion concentration and dissolved ¹³⁷Cs concentration at all sites. However, a positive correlation between dissolved cesium concentration and water temperature and DOC and water temperature was observed at all sites regardless of the presence of K⁺ and NH₄⁺. On the other hand, there was no clear relationship between the cesium concentrations in SS and organic matter and water temperature. These results suggest that the seasonal variation in dissolved Cs-137 concentrations in stream water with water temperature could be caused by the seasonality of microbial decomposition of organic matter.

How to cite: Kawano, T., Onda, Y., Takahishi, J., Makino, F., and Iwagami, S.: Seasonal variation of dissolved Cs-137 concentrations in headwater catchments in Yamakiya district, Fukushima Prefecture, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7068, https://doi.org/10.5194/egusphere-egu22-7068, 2022.

EGU22-1235 | Presentations | GI2.3

Modeling the depth dependence of Cs-137 concentration in Lake Onuma 

Yuko Hatano, Kentaro Akasaki, Eiichi Suetomi, Yukiko Okada, Kyuma Suzuki, and Shun Watanabe

Lake Onuma on Mt. Akagi (Gunma Prefecture, Japan) is a closed lake with an average water residence time of 2.3 years. The activity concentration of radioactive cesium in the lake was high shortly after the Fukushima accident. According to Suzuki et al. [1] and Watanabe [2], after a filtration process, Cs-137 are separated into two groups: particulate form and dissolved form. These two forms appears to have very different concentration profiles with each other,  when the Cs-137 concentration plotted against the sampled water depths. In the present study, we are going to model those behavior of particulate/dissolved forms with an emphasis on the depth dependency.

We consider a creation-annihilation process of plankton for the model of the particulate form, since diatom shells are found to be a major constituent of the particulate Cs-137 [2]. We set  ∂P/∂t = f(x,t)  and  f(x,t) = χ(x) cos(ωt) (0 ≤ x ≤ L(water column height), t > 0),  where P=P(x,t) is the activity concentration of the particulate form. The term f(x,t) is the rate of the net production of the plankton at a specific location x at a specific time t. Seasonal cycle is also taken into account by the cosine function (we neglect the phase shift here). The function χ(x), depends solely on water depth x, is responsible for dynamics or inhomogeneity of lake water, such as circulation, stratification or a thermocline. We assume that such a water structure relates to the production rate of plankton through the function χ(x). Thus, we may obtain the concentration of particulate Cs-137. For the dissolved concentration S(x,t), we use the classical diffusion equation with the diffusivity K being dependent on both space and time (i.e. K(x,t)), namely ∂S/∂t =  ∇•(K(x,t) ∇S). Here S=S(x,t) is the activity concentration of the dissolved form. The total activity concentration C(x,t) is the sum of P(x,t) and S(x,t). Using the pair of the equations, we can reproduce the followings. (1) depth profiles of each of the soluble- and particulate activity concentration and (2) depth profiles of the total Cs-137 concentration.

 [1] Suzuki, K. et al., Sci. Tot. Env. (2018)

 [2] Watanabe, S. et al.,  Proc. 20th Workshop on Environmental Radioactivity (2019)

How to cite: Hatano, Y., Akasaki, K., Suetomi, E., Okada, Y., Suzuki, K., and Watanabe, S.: Modeling the depth dependence of Cs-137 concentration in Lake Onuma , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1235, https://doi.org/10.5194/egusphere-egu22-1235, 2022.

Radiocesium (137Cs) was one of the radioactive materials released from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in March 2011. Highly 137Cs contaminated water from groundwater to the sea was reduced after installation of the sea-side impermeable wall as a countermeasure against contaminated water in October 2015. As a result, 137Cs contamination in water from other sources became more prominent and the levels of 137Cs concentration in seawater was correlated with rainfall fluctuation. To determine the source of contamination, we estimated the fluctuation patterns of 137Cs concentration in seawater, groundwater level, and discharge from the channels using the Antecedent Precipitation Index (Rw) method.
The results indicated that the fluctuation in seawater collected near the 1-4 Units had strong agreement with the 3 day half-life of Rw. The half-life is shorter than that estimated by groundwater level (7 to 30 day). Therefore, the 137Cs concentration in seawater was influenced by relatively faster runoff than the deep groundwater flow. We also made the spatial distribution map of 137Cs concentration in seawater to determine the sources of contamination. It showed that the 137Cs contaminated area was the highest at “south- inside the intake of 1-4 Units” where the outlets of the K and BC discharge channels are located. In particular, the concentration of 137Cs in the channel K was found to correlate with the concentration of 137Cs in seawater near the 1-4 Units (average of R2 = 0.5). These results indicate that the concentration of 137Cs in seawater inside the FDNPP port can be estimated by the Rw method and that the source of the contamination could be determined using the half-life.

How to cite: Sato, H. and Onda, Y.: Determining sources of the 137Cs concentration in seawater at Fukushima Daiichi Nuclear Power Plant using Antecedent Precipitation Index, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9055, https://doi.org/10.5194/egusphere-egu22-9055, 2022.

EGU22-10817 | Presentations | GI2.3

Effects of stemflow on radiocesium infiltration into the forest soil

Hiroaki Kato, Hikaru Iida, Tomoki Shinozuka, Yuma Niwano, and Yuichi Onda

Radiocesium deposited in the forest canopy is transferred to the forest floor by rainwater and litterfall. Among them, stemflow likely increases the radiocesium inventory by concentrating rainwater around the trunk. However, the effects of stemflow on the influx of radiocesium into forest soil have not been evaluated quantitatively. In this study, the fluxes of rainwater via stemflow, throughfall, and soil infiltration water were observed. The concentration of dissolved 137Cs was measured in a cedar forest in Fukushima Prefecture, Japan. Soil infiltration water was collected at 5 cm and 20 cm depths at the distant point from the tree trunk (Bt), and the base of the tree trunk (Rd), where the influence of stemflow was strong. The observations were conducted during the period from September 2019 to November 2021. During the observation period, an experiment was conducted to intercept the inflow of rainwater via the throughfall or stemflow, and the change in soil infiltration water was observed. The observation results showed that the infiltration flux of radiocesium into the forest soil was significantly higher at the Rd site and about three times larger than at the Bt site. Particularly at the 20 cm depth at the Rd site, the soil infiltration water flux increased with the stemflow. The stemflow exclusion resulted in the dcrease of radiocesium flux by about 70% at all depths at the Rd site. These results suggest that the stemflow increases the input of radiocesium to the base of the tree trunk and facilitates its transfer to the deeper soil layers.

How to cite: Kato, H., Iida, H., Shinozuka, T., Niwano, Y., and Onda, Y.: Effects of stemflow on radiocesium infiltration into the forest soil, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10817, https://doi.org/10.5194/egusphere-egu22-10817, 2022.

EGU22-11620 | Presentations | GI2.3

Methodology for estimating the emission of radionuclides into the atmosphere from wildfires in the Chernobyl Exclusion Zone

Valentyn Protsak, Gennady Laptev, Oleg Voitsekhovych, Taras Hinchuk, and Kyrylo Korychenskyi

Most of the territory of the Chernobyl Exclusion Zone (CEZ) is covered by forest. Forest of CEZ have accumulated a significant part of the radioactive release and for many years have served as a barrier to the non spreading of the radionuclide contamination outside the CEZ.

According to the classification of wildfire danger, the forests of CEZ belong to high, above average and medium classes, making cases of wildfires as quite common.

Poor, sod-podzolic soils of Ukrainian Polesye contribute to the entry the activity of 90Sr and 137Cs in plant biomass. During wildfires some of the radionuclides contained in combustion products of biomass are emitted into the atmosphere. Biologically important radionuclides such as 90Sr, 137Cs, plutonium isotopes and 241Am bound to fine aerosols - combustion products - can be transported with atmospheric flows over the long range, causing secondary radioactive fallout and forming additional inhalation dose loads on the population.

Lack of the actual information on the source term (rate of emission of radionuclides) does not allow reliable modeling of the radiological impact of wildfires. To address this issue, we have proposed a methodology that allows for operational assessments of the dynamics of radionuclide emissions into the atmosphere from wildfires in the CEZ.

The basic parameters for the calculations are

  • cartographic data on the density of radionuclide contamination of the territory of the CEZ;
  • classification of the territory of the CEZ according to the distributive features of forests and meadows;
  • classification of CEZ forests according to taxa characteristics to estimate amount of stored fuel biomass (kg/m2);
  • experimental data on the transfer of radionuclides from soil to the main components of biomass for the calculation of radionuclide inventory in fuel biomass (Bq/m2). Thus, for meadows the main fuel component is grass turf, while for forest these are litter, wood, bark and pine needles.
  • experimental data on emission factors of radionuclides from fuel biomass.

Implementation of the proposed algorithm in the form of GIS application makes it possible to assess the dynamics of radionuclide emission into the atmosphere by delineation the fire areas on the CEZ map. The NASA WorldView interactive mapping web application can be used to estimate the temporal and spatial characteristics of the wildfire while it is being developed. The contouring of the area affected by fire is carried out according to the analysis of the cluster of thermal points. Also, operational contouring of wildfire can be carried out using data delivered from unmanned aerial vehicles.

The application of the proposed algorithm for the analysis of the dynamics of 137Cs emissions into the atmosphere from the April 2020 wildfire showed a good agreement with the data reported by various authors who used the method of inverse simulation. Improving the accuracy of calculations according to the proposed algorithm can be done by rectifying radionuclide emission factors and taking into account fire intensity data, which in turn can affect both the radionuclide emission factor and the degree of burnout of plant biomass.

How to cite: Protsak, V., Laptev, G., Voitsekhovych, O., Hinchuk, T., and Korychenskyi, K.: Methodology for estimating the emission of radionuclides into the atmosphere from wildfires in the Chernobyl Exclusion Zone, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11620, https://doi.org/10.5194/egusphere-egu22-11620, 2022.

A study of 137Cs distribution in a landscape cross-section characterizing the ELGS system (top-slope-closing depression) in the “Vyshkov-2” test site located in the Chernobyl abandoned zone, the Bryansk region, Russia, has been performed in 2015 and 2021. The test site (70×100 m) is located on the Iput’ river terrace in a pine forest characterized by the undisturbed soil-plant cover. Sod-podzolic sandy illuvial-ferruginous soils present the soil cover. The initial level of 137Cs contamination of the area varied from 1480 kBq/m2 to 1850 kBq/m2. Up to now, 89-99 % of the total 137Cs is fixed in the upper 20 cm soil layer with 70-96 % in the upper 8 cm. It allows field spectrometry data to study the structure of the 137Cs contamination field. The 137Cs activity was measured in the soil and moss cover along cross-sections with 1 m step by adapted gamma-spectrometer Violinist-III (USA). Cs-137 content in the soil cores’ and plant samples was determined in the laboratory by Canberra gamma-spectrometer with HPGe detector. It was shown that there is no unidirectional movement of 137Cs both in the soil and in the vegetation cover of the ELGS from the top to the closing depression. On the contrary, the data obtained allow us to state a pronounced cyclical variation of the 137Cs activity in ELGS, which can be traced in the soil and the vegetation. The variation appeared to be rather stable in space 29 and 35 years after the primary pollution. Cyclic fluctuation (variation) of 137Cs activity was described mathematically using Fourier-analysis, which was used to model the observed changes by the revealed three main harmonics. High and significant correlation coefficients obtained between the variation of 137Cs activity and the model for the soil-vegetation cover (r0,01= 0,868; n=17 - 2015; r0,01= 0,675; n=17 - 2021), soils (r0,01= 0,503-0,859; n=17) and moss samples (r0,01= 0,883; n=17 - 2015; r0,01= 0,678; n=17 - 2021) proved satisfactory fitting of models. The character of 137Cs variability in moss cover was generally similar to surface soil contamination, but the level of contamination and amplitude was specific.

The performed study confirmed specific features of 137Cs secondary migration in ELGS, which periodic functions describe. We infer that the observed cyclicity reflects elements’ migration in the ELGS system with water.

The reported study was funded by the Vernadsky Institute federal budget (research task #0137-2019-0006). The field works were supported partly by RFBR No 19-05-00816.

How to cite: Dolgushin, D. and Korobova, E.: Regularities of the 137Cs secondary distribution in the soil-moss cover of elementary landscape-geochemical systems and its dynamics within 6 years on the test site in the Chernobyl abandoned zone, Russia, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8178, https://doi.org/10.5194/egusphere-egu22-8178, 2022.

Human activities such as mining and processing of naturally occurring radioactive materials have a potential to result in enhanced radioactivity levels in the environment. In South Africa, there has been extensive mining of gold and uranium which produced large mine tailings dams that are highly concentrated with radioactive elements. The purpose of this study was to carry out a preliminary survey on a large scale to assess the activity concentrations of 238U, 232Th and 40K in mine tailings, soils and outcropping rocks in the West Rand District in South Africa. This was done to better understand the impact of the abandoned mine tailings on the surrounding soil. This study employed in-situ gamma spectrometry technique to measure the activity concentrations of 238U, 232Th and 40K. The portable BGO SUPER-SPEC (RS-230) spectrometer, with a 6.3 cubic inches Bismuth Germanate Oxide (BGO) detector was used for in-situ measurements. In mine tailings the activity concentrations for 238U, 232Th and 40K were found to range from 209.95 to 2578.68 Bq/kg, 19.49 to 108.00 Bq/kg and 31.30 to 626.00 Bq/kg, respectively. In surface soil, the activity concentration of 238U for all measurements ranged between 12.35 and 941.07 Bq/kg, with an average value of 59.15 Bq/kg. 232Th levels ranged between 12.59 and 78.36 Bq/kg, with an average of 34.91 Bq/kg. For 40K the average activity concentration was found to be 245.64 Bq/kg, in a range of 31.30 - 1345.90 Bq/kg. For the rock samples analyzed, average activity concentrations were 32.97 Bq/kg, 32.26 Bq/kg and 351.52 Bg/kg for 238U, 232Th and 40K, respectively. The results indicate that higher radioactivity levels are found in mine tailings than in rocks and soils. 238U was found to contribute significantly to the overall activity concentration in tailings dams as compared to 232Th and 40K. It has been observed that the mine tailings have a potential to impact on the activity concentration of 238U in soil in the immediate vicinity. However, on a regional scale it was found that the radioactivity levels in surface soil mainly depend on the radioelement concentration of the underlying rocks. The contamination is only confined to areas where mine tailings materials are washed off and deposited on surface soils in close proximity to tailings sources. This serves as an indication that the migration of uranium from tailings dams is localized and occurs within short distances. It is recommended that further radiological monitoring be conducted in areas found to have elevated concentration of uranium-238.

Keywords-In-situ gamma-ray spectrometry, Mine tailings, Radioactivity, Soil.

How to cite: Moshupya, P., Abiye, T., and Korir, I.: In-situ measurements of natural radioactivity levels in the gold mine tailings dams of the West Rand District, South Africa., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11669, https://doi.org/10.5194/egusphere-egu22-11669, 2022.

EGU22-9022 | Presentations | GI2.3

Ten-year long-range transport of radiocaesium in the surface layer in the Pacific Ocean and its marginal seas

Michio Aoyama, Yuichiro Kumamoto, and Yayoi Inomata

Radiocaesium derived from the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident was observed across a wide area of the North Pacific, not only in surface seawater, but also in the ocean interior. In this presentation, we summarized the time scale of Lagrangian transport of the FNPP1 derived radiocaesium in surface water during the period from the time of the accident to March 2021 in the North Pacific and the Arctic Oceans and its marginal seas as shown below.

Initial observation results until December 2012 in the surface layer in the North Pacific Ocean by the global observations revealed that a typical feature within one year after the accident was a westward movement across the North Pacific Ocean, speed of which was reported at 7 km day-1 until August 2011. After that, the main body of FNPP1-derived radiocaesium moved east as 3 km day-1 and is separated from Japan in 2013. The arrival of the FNPP1 signal at the west coast of the American continent was reported in 2014. The elevation in the FNPP1 derived radiocaesium concentration in the Bering Sea in 2017 and in the Arctic Ocean in 2019 was reported. The northward bifurcation of the Kuroshio Extension made these obvious transport of the FNPP1 derived radiocaesium to the subarctic and arctic region while the transport by southward bifurcation was not observed. At Hawaii Islands in the subtropical gyre, there was no signal of the FNPP1 derived radiocaesium during the period from March 2011 and February 2017. At Yonaguni Island where the Kuroshio enters the East China Sea, the FNPP1 signal arrived at Yonaguni Islands eight years after the time of the accident, and these might be transported mainly from the subtropical gyre.

At the marginal seas of the North Pacific Ocean, the elevation in the FNPP1 derived radiocaesium concentration in the northern East China Sea in 2014, in the Sea of Japan in 2014/2015 were observed.

We also briefly summarize study results on nuclides other than radiocaesium (e.g., 90Sr, 239240Pu, and 129I).

How to cite: Aoyama, M., Kumamoto, Y., and Inomata, Y.: Ten-year long-range transport of radiocaesium in the surface layer in the Pacific Ocean and its marginal seas, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9022, https://doi.org/10.5194/egusphere-egu22-9022, 2022.

European seas such as, Baltic, North, and Norwegian Seas are mostly affected areas by the accident at the Chernobyl nuclear power plant (CNPP) in 1986. Since Fukushima Daiichi nuclear power plant (FDNPP) is located on the coast of the North Pacific Ocean in east Japan, its accident resulted in the release of large amounts of radiocesium to the surrounding coastal marine environment (i.e. the waters off Fukushima and neighboring prefectures). The temporal change of radiocaesium concentration in seawater after both accidents was largely dependent on their submarine topography: The Baltic Sea is a semi-closed basin, while Norwegian and North Seas, and the waters off Fukushima and neighboring prefectures is directly connected to open-water. Although concentration of radioacesium (137Cs) in the surface water of the Baltic Sea (central part) continuously decreased, the values in 1996, ten years after the accident, were even higher than pre-accident level in 1985. On the other hand, in the waters off Fukushima and neighboring prefectures 137Cs concentrations in 2020, nine years after the accident, are approaching the pre-accident levels of 2010. The quick decrease is attributable to the intrusion or mixing of water masses with low 137Cs.

How to cite: Takata, H.: Temporal trends of radio-cesium concentration in the marine environment after the Chernobyl and Fukushima Dai-ichi Nuclear Power Plant accidents, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10644, https://doi.org/10.5194/egusphere-egu22-10644, 2022.

EGU22-11022 | Presentations | GI2.3

Estimation of 137Cs inventories in each ocean basin by a global ocean general circulation model for the global database interpolation

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 by atmospheric nuclear weapons tests, releases from reprocessing plants in Europe, and supplied to the ocean by the Fukushima Daiichi Nuclear Power Plant (1F NPP) 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, observed data have been summarized in a historical database (MARIS) by IAEA. The spatio-temporal density of the observations varies widely, therefore simulation by an ocean general circulation model (OGCM) can be helpful in the interpretation of these observations.

In order to clarify the behavior of 137Cs in the global ocean, OGSM simulations were conducted. Parallel Ocean Program version 2 (POP2) of the Community Earth System Model version 2 (CESM2) is employed. The horizontal resolution is 1.125 degree of longitude, and from 0.28 degree to 0.54 degree of latitude. There are 60 vertical levels with a minimum spacing of 10 m near the ocean surface, and increased spacing with depth to a maximum of 250 m. The simulated period was from 1945 to 2030 with the circulation forced by repeating (“Normal Year”) atmospheric conditions. As input sources of 137Cs to the model, global fallout from atmospheric nuclear tests, releases from reprocessing plants in Europe, and input from the 1F NPP accident were considered. It was assumed that the input conditions in 2020 would continue after 2020.

The simulated 137Cs activity agrees well with the observed data in the database, especially in the Atlantic and Pacific Oceans where the observation density is large. Since 137Cs undergoes radioactive decay with a half-life of 30 years, the inventory for each basin is the difference between the decay corrected cumulative input and flux. In the North Pacific, the inventory reached its maximum in 1966 due to the global fallout by atmospheric nuclear weapons tests. Fluxes from the North Pacific to the Indian Ocean, Arctic Ocean, and Central Pacific were positive, and the North Pacific was a source of supply for other ocean basins. The 1F NPP accident caused a 20% increase in the inventory in 2011. In the North Atlantic, the inventory reaches its maximum in the late 1970s, due to the releases from the reprocessing plant. The outflow flux from the North Atlantic to the Greenland Sea is larger than the other fluxes and is a source of supply to other ocean basins. After 2000, the inflow flux to the North Pacific from the Labrador Sea and the South Atlantic is larger than the outflow flux.

The time series of 137Cs inventory in each ocean basin and the fluxes among ocean basins were quantitatively analyzed by OGCM simulations, and the predictions for the next 10 years were made.  The 137Cs activity concentrations by global fallout can be detected in the global ocean after 2030. The OGCM simulations will be useful in 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.: Estimation of 137Cs inventories in each ocean basin by a global ocean general circulation model for the global database interpolation, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11022, https://doi.org/10.5194/egusphere-egu22-11022, 2022.

EGU22-666 | Presentations | GI2.3

Dry deposition velocity of chlorine 36 on grassland

Sourabie Deo, Didier Hebert, Lucilla Benedetti, Elsa Vitorge, Beatriz Lourino Cabana, Valery Guillou, and Denis Maro

Chlorine 36 (36Cl, T1/2 = 301,000 years) is a radionuclide with natural and anthropogenic origin that can be rejected accidentally during decommissioning of nuclear power plants or chronically during recycling of nuclear waste. Once emitted into the atmosphere, 36Cl (gas and particles) can be transferred to the soil and vegetal cover by dry and wet deposition. However, knowledge of these deposits is very scarce. Because of its relatively high mobility in the geosphere and its high bioavailability, 36Cl fate in the environment should be studied for environmental and human impact assessments. So, the objective of this work is to determine the dry deposition rates of chlorine 36 on grassland. Grass is studied, as it is a link in the human food chain via cow's milk.

In order to achieve this objective, a method for extracting the chlorine contained in plant leaves has been developed. This method consists in heating the dried and grounded plant sample in presence of sodium hydroxide. A temperature gradient up to 450°C allows the extraction to be carried out in two stages: (i) The chlorides with a strong affinity for alkaline environments are first extracted from the plant and preserved in sodium hydroxide; (ii) The organic matter is then destroyed by combustion and the sodium hydroxide crystallised. Brought out from the oven, the dry residue is dissolved in ultrapure water and chemically prepared for the measurement of chlorine 36. This extraction method was validated by its application to NIST standards of peach and apple leaves. The average extraction efficiency of chlorides was 83 ± 3%.

For the determination of dry deposition rates, 1m2 of grass was exposed every 2 weeks at the IRSN La Hague technical platform (PTILH) located 2 km downwind from Orano la Hague, a chronic source of low-level chlorine 36 emissions. A mobile shelter with automatic humidity detection covered the grass during rainy episodes. In proximity to the grass, atmospheric chlorine was also sampled at the same frequency as the grass. Gaseous chlorine was sampled by bubbling in sodium hydroxide and by an AS3000 sampler containing activated carbon cartridge. Particulate chlorine was collected on a composite (teflon and glass fibre) filter. Chlorine 36 was measured by accelerated mass spectrometry ASTER (Accelerator for Earth Sciences, Environment and Risks) at CEREGE, Aix-en-Provence, France. All samples were subjected to a succession of chemical preparations in order to remove the sulphur 36 (an isobaric interferent) and to collect the chlorides in the form of AgCl pastilles. The results show a chlorine 36 deposition flux on the grass of 2.94.102 at/m2.s with a deposition velocity in dry weather vd(gas+particles) = 8.10-4 m/s for a contribution of 65.5% of particulate chlorine 36 and 34.5% of gaseous chlorine 36. Based on these experimental results, a modelling of the dry and wet deposits will be carried out considering the parameters related to the canopy and the atmospheric turbulence.

How to cite: Deo, S., Hebert, D., Benedetti, L., Vitorge, E., Lourino Cabana, B., Guillou, V., and Maro, D.: Dry deposition velocity of chlorine 36 on grassland, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-666, https://doi.org/10.5194/egusphere-egu22-666, 2022.

Wet deposition has been identified as a critical impactor for the modelling of 137Cs in the Fukushima Daiichi Nuclear power plant (FDNPP) accident. However, it is difficult to simulate due to the involvement of close interaction between various complicated meteorological and physical processes during the wet deposition process. The limitation of measurement of the in-cloud and below-cloud scavenging also contribute to the uncertainty in wet deposition modeling, leading to the great variation of 137Cs wet deposition parameterization. These variations can be amplified further by inaccurate meteorological input, making simulation of radionuclide transport sensitive to the choice of wet scavenging parameterization. Moreover, simulations can also be influenced by differences between radionuclide transport models, even if they adopt similar parameterization for wet scavenging. Although intensively investigated, wet deposition simulation is still subject to uncertainties of meteorological inputs and wet scavenging modeling, leading to biased 137Cs transport prediction.

To improve modeling of 137Cs transport, both in- and below-cloud wet scavenging schemes were integrated into the Weather Research and Forecasting-Chemistry (WRF-Chem) model, yielding online coupled modeling of meteorology and the two wet scavenging processes. Overall, 25 combinations of different in- and below-cloud scavenging schemes of 137Cs, covering most wet scavenging schemes reported in the literature, were integrated into WRF-Chem. Additionally, two microphysics schemes were compared to improve the simulation of precipitation. These 25 models and the ensemble mean of 9 representative models were systematically compared with a previous below-cloud-only WRF-Chem model, using the cumulative deposition and atmospheric concentrations of 137Cs measurements. The findings could elucidate the range of variation among these schemes both within and across the five in-cloud groups, reveal the behaviors and sensitivities of different schemes in different scenarios.

The results revealed that the Morrison's double moment cloud microphysics scheme improves the simulation of rainfall and deposition pattern. Furthermore, the integration of the in-cloud schemes in WRF-Chem substantially reduces the bias in the cumulative deposition simulation, especially in the Nakadori and Tochigi regions where light rain dominated. For atmospheric concentration of 137Cs, those models with in-cloud schemes that consider cloud parameters showed better and more stable performance, among which Hertel-Bakla performed best for atmospheric concentration and Roselle-Apsimon performed best for both deposition and atmospheric concentration. In contrast, the in-cloud schemes that rely solely on rain intensity were found sensitive to the meteorological conditions and showed varied performance in relation to the plume events examined. The analysis based on the spatial pattern shows that the Roselle scheme, which considers cloud liquid water content and depth, can achieve a more balanced allocation of 137Cs between the air and the ground in these two cases than that achieved by the empirical power function scheme Environ. The ensemble mean achieves satisfactory performance except for one plume event, but still outperforms most models. The range of variation of the 25 models covered most of the measurements, reflecting the reasonable capability of WRF-Chem for modeling 137Cs transport.

How to cite: Zhuang, S., Dong, X., and Fang, S.: Sensitivity analysis on the wet deposition parameterization for 137Cs transport modeling following the Fukushima Daiichi Nuclear Power Plant accident, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-177, https://doi.org/10.5194/egusphere-egu22-177, 2022.

EGU22-5397 | Presentations | GI2.3

Integrating measurement representativeness and release temporal variability to improve the Fukushima-Daiichi 137Cs source reconstruction

Joffrey Dumont Le Brazidec, Marc Bocquet, Olivier Saunier, and Yelva Roustan

    The Fukushima-Daiichi accident involved massive and complex releases of radionuclides in the atmosphere. The releases assessment is a key issue and can be achieved by advanced inverse modelling techniques combined with a relevant dataset of measurements. A Bayesian inversion is particularly suitable to deal with this case. Indeed, it allows for rigorous statistical modelling and enables easy incorporation of informations of different natures into the reconstruction of the source and the associated uncertainties.
    We propose several methods to better quantify the Fukushima-Daiichi 137Cs source and the associated uncertainties. Firstly, we implement the Reversible-Jump MCMC algorithm, a sampling technique able to reconstruct the distributions of the 137Cs source magnitude together with its temporal discretisation. Secondly, we develop methods to (i) mix both air concentration and deposition measurements, and to (ii) take into account the spatial and temporal information from the air concentration measurements in the error covariance matrix determination.
    Using these methods, we obtain distributions of hourly 137Cs release rates from 11 to 24 March and assess the performance of our techniques by carrying out a model-to-data comparison. Furthermore, we demonstrate that this comparison is very sensitive to the statistical modelling of the inverse problem.

How to cite: Dumont Le Brazidec, J., Bocquet, M., Saunier, O., and Roustan, Y.: Integrating measurement representativeness and release temporal variability to improve the Fukushima-Daiichi 137Cs source reconstruction, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5397, https://doi.org/10.5194/egusphere-egu22-5397, 2022.

The nuclear emergency response for accidental release around the nuclear power plant site (NPPs) requires a fast and accurate estimate of the influence caused by gaseous hazardous pollutants spreading, which is critical for and preventing protecting lives, creatures, and the environment. However, as usual, the NPPs is consist of dense buildings and multi-type terrain, e.g. river and mountain, which poses challenges to atmospheric dispersion calculation for response tasks. Micro-SWIFT SPRAY (MSS) comprises both the diagnostic wind model and the dispersion model, which enables the airflows and atmospheric dispersion simulation with the meteorological and other inputs. For a small-scale scenario, especially, the separate module for obstacles influence modeling provides the potential capability of precise atmospheric dispersion. But the error behavior of such a scenario around a nuclear power plant site with complex topography remains to be further demonstrated. In this study, MSS is comprehensively evaluated against a wind tunnel experiment with a 1:600 scale for the small-scale (3 km × 3km) atmospheric dispersion modeling. Tens of buildings located in this scenario of a NPPs surrounded by a mountain and river. The evaluations for diagnostic wind modeling include the speed, direction, and distribution of horizontal airflows and vertical profile of speed at a representative site. And for the concentration calculation, horizontal distribution, axis profile, and vertical profile at a representative site. The results demonstrate the MSS can reproduce fine airflows near the buildings but overestimate the wind speed. The maximum deviation of vertical speed is around 2.09 m/s at the representative site. The simulated plume of concentration reproduces the highest concentration place and matches the observations well. The axis profile of concentration is underestimated and the vertical profile displays an increasing deviation with the height increase. Compared with the observations, the FAC5 and FAC2 of concentration simulation reach 0.945 and 0.891 in the entire calculation domain, which convinces the performance of MSS in small-scale modeling.

How to cite: Dong, X., Zhuang, S., and Fang, S.: Micro-SWIFT SPRAY modeling of atmospheric dispersion around a nuclear power plant site with complex topography, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-190, https://doi.org/10.5194/egusphere-egu22-190, 2022.

EGU22-11571 | Presentations | GI2.3

Mapping of Post-Disaster Environments using 3D Backprojection and Iterative Inversion Methods Optimised for Limited-Pixel Gamma Spectrometers on Unoccupied Aerial Systems (UAS). 

Dean Connor, David Megson-Smith, Kieran Wood, Robbie Mackenzie, Euan Connolly, Sam White, Freddie Russell-Pavier, Matthew Ryan-Tucker, Peter Martin, Yannick Verbelen, Thomas Richardson, Nick Smith, and Thomas Scott

All radiological measurements acquired from airborne detectors suffer from the issues of geometrical signal dilution, signal attenuation and a complex interaction of the effective sampling area of the detector system with the 3D structure of the surrounding environment. Understanding and accounting for these variables is essential in recovering accurate dose rate maps that can help protect responding workforces in radiologically contaminated environments.

Two types of terrain-cognisant methods of improving source localisation and the contrast of airborne radiation maps are presented in this work, comprising of ‘Point Cloud Constrained 3D Backprojection’ and ‘Point Cloud Constrained Randomised Kaczmarz Inversion’. Each algorithm uses a combination of airborne gamma-spectrometry and 3D scene information collected by UAS platforms and have been applied to data collected with lightweight, simple (non-imaging) detector payloads at numerous locations across the Chornobyl Exclusion Zone (CEZ).

Common to both the algorithms is the projection of the photopeak intensity onto a point cloud representation of the environment, taking into account the position and orientation of the UAS in addition to the 3D response of the spectrometer. The 3D Backprojection method can be considered a relatively fast method of mapping of through proximity, in which the measured photopeak intensity is split over the point cloud according to the above factors. It is an additive technique, with each measurement increasing the overall magnitude of the radiation field assigned to the survey area, meaning that more measurements continues to increase the total radiation of the site. The total measured intensity of the solution is then normalised according to the time spent in proximity to each point in the scene, determined by splitting and projecting the nominal measurement time at each survey point over the point cloud according to the distance from the survey position. Thus accounting for sampling biases during the survey.

The inversion approach adapts algorithms routinely used in medical imaging for the unconstrained world in which the detector is no longer completely surrounding the subject/target. A forward projection model, based on the contribution of distant point sources to the detector intensity, is used to determine the relationship between the full set of measurements and the 3D scene. This results in a hypercube of linear equations where it is assumed every point in the scene contributes to the measured intensity. The algorithm randomly adds measurements from within the aerial set and back-projects this onto the point cloud, with the initial state of the solution set to emit no radiation. After a given number of iterations, the fit of the current solution to the original measurements is assessed though a least squares method and updated when this produces a fit better than the current best estimate. This continues to happen until a minimum value is reached before the divergence of the system, representing the most confident solution. Based on examples from both simulations and real world data, the improvement in contrast of airborne maps using this inversion method can make them equivalent to ground-based surveys, even when operating at 20 m AGL and above.

How to cite: Connor, D., Megson-Smith, D., Wood, K., Mackenzie, R., Connolly, E., White, S., Russell-Pavier, F., Ryan-Tucker, M., Martin, P., Verbelen, Y., Richardson, T., Smith, N., and Scott, T.: Mapping of Post-Disaster Environments using 3D Backprojection and Iterative Inversion Methods Optimised for Limited-Pixel Gamma Spectrometers on Unoccupied Aerial Systems (UAS). , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11571, https://doi.org/10.5194/egusphere-egu22-11571, 2022.

EGU22-11502 | Presentations | GI2.3

Retrospective assessment of 14C aquatic and atmospheric releases from Ignalina Nuclear Power Plant due to exploitation of two RBMK-1500 type reactors

Evaldas Maceika, Rūta Barisevičiūtė, Laurynas Juodis, Algirdas Pabedinskas, Žilvinas Ežerinskis, Justina Šapolaitė, Laurynas Butkus, and Vidmantas Remeikis

Considerable amounts of 14C in the nuclear reactor are generated by neutrons. It accumulates in reactor components, coolant, and cleaning systems, and partly is released into the environment as gaseous releases and as liquid effluents. Two RBMK-1500 type reactors were exploited at Ignalina NPP (Lithuania) 1983-2009. Releases from NPP radiocarbon accumulated in local biosphere by photosynthesis, including terrestrial and aquatic media, as INPP used Lake Drūkšiai as a cooling pond

Temporal variation of 14C in lake ecosystem was examined by analyzing measured radiocarbon concentration of the organic compounds (Alkali soluble-AS) and alkali insoluble-AIS) derived from the layers of the Drūkšiai lake bottom sediments. The lake sediment cores were sampled in 2013 and 2019, sliced to 1 cm layers and 14C concentration was measured of every layer. AS and AIS organic fractions of sediment samples were extracted by using the acid-base-acid method.

Tree ring cores were collected from Pinus Sylvestris pines around the Ignalina NPP site at different directions and distances. Cellulose extraction was performed with BABAB (base-acid-base-acid-bleach) procedure, and all samples were graphitized and measured by a single state accelerator mass spectrometry at Vilnius Radiocarbon facility. Tree rings 14C concentration analysis provides atmospheric radiocarbon concentration in locations around the nuclear object. This analysis provides an opportunity to evaluate the impact of a nuclear object on water and terrestrial ecosystems.

The results showed a pronounced increase of 14C above background up to 17.8 pMC in the tree rings during INPP exploitation as well during decommission (since 2010) periods. According to the recorded data in 2004-2017 of the local Ignalina NPP meteorological station, the prevailing wind direction was towards the North and East during warm and light time periods. The radiocarbon released from the INPP stack dilutes when it travels in a downwind direction from the INPP. However, even 6.6 km away from the INPP, the impact of the power plant is still clearly visible. By using our created Gaussian dispersion model, the estimated annual emissions of 14C activity from the Ignalina NPP to the air vary from year to year. When only the 1st INPP reactor Unit was operating in 1985-1987, average emissions were 1.2 TBq/year. Emissions almost doubled to 2.1 TBq/year in 1988, when the 2nd Unit became operational. Later, emission levels increased. It could be explained by the large amount of 14C accumulating in the graphite of the RBMK reactor and its gradual release.

14C concentration profile analysis of the lake bottom sediments core revealed a significant impact of the Ignalina NPP on the Drūkšiai lake ecosystem. An increase of 14C concentration in the layers of bottom sediments by 80 pMC in the AS fraction and only by 9 pMC in the AIS fraction was observed, corresponding to the period about years of 1998-2003. The maximum peak in AS of 189 pMC was reached approximately in 2001, followed by gradual lake recovery. This radiocarbon peak in the lake represents a large single one-time pollution release. The critical period was in 2000s when maintenance works of the reactors were performed.

How to cite: Maceika, E., Barisevičiūtė, R., Juodis, L., Pabedinskas, A., Ežerinskis, Ž., Šapolaitė, J., Butkus, L., and Remeikis, V.: Retrospective assessment of 14C aquatic and atmospheric releases from Ignalina Nuclear Power Plant due to exploitation of two RBMK-1500 type reactors, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11502, https://doi.org/10.5194/egusphere-egu22-11502, 2022.

GI3.1 – Analogue Planetary Research and Instruments

EGU22-10308 | Presentations | GI3.1

Callio Spacelab - An underground laboratory for future exploration and analogue missions in Finland

Jari Joutsenvaara, Marko Holma, Ilkka Hynynen, Ossi Kotavaara, and Julia Puputti

An isolated but highly connected underground mine can be used as an analogue environment for the astronauts operating without sight to the home planet and with limited connectivity to the psychologically-important “home”. Similarly to the real-world space mission, the Earth-bound analogue mission can be run with limited resources, i.e., just enough for the duration of the mission. Such a location is available in Pyhäjärvi, Finland.

The conceptualisation of the use of the Pyhäsalmi mine as an analogue environment for space missions started in 2017 with an idea of a Marscape environment to be developed in the old part of the mine. The 1.4-km-deep base metal mine is ending its underground ore extraction (zinc, copper and pyrite as main products) in 2022. The concept is branded as Callio SpaceLab 1, and it has been developed by the Univerisity of Oulu, Finland, in cooperation with international partners. The Callio SpaceLab is part of the underground research centre Callio Lab 2, and it is one of the strategic research infrastructures of the University of Oulu.

The mine is located within a volcanogenic massive sulphide (VMS) deposit 3, with known mineralisation reaching a depth of 1.4 km. Deep overpressured ancient water-conducting fracture zones have occasionally been intersected by drilling. Water of this kind is accessible through a high-pressure valve system, making further analyses possible, especially from the astrobiological point of view.

The vast tunnel network with more than 100 km of tunnels, old main levels and operational areas give room for any activities ranging from technological testing to having analogue astronauts in total isolation. With the optical baseline and copper and wireless access, personnel and monitoring activities are possible through a 1+GB on-site internet connection, from the surface or securely through a VPN access. Moreover, there are two underground, hydroponic greenhouses built at the 660 m level. These can be used for analogue missions. The well-known geology gives many possibilities for scientific drilling, on-site analysis, and possibly in-situ resource utilisation.

The multidisciplinary University of Oulu has turned its eye to the stars. Many earthbound research topics are being evaluated from the space exploration viewpoint. These include mining technologies and processes 4, such as free crushing and comminution 5, dry beneficiation, digital construction, and geophysical methodologies.

We will present the possibilities brought by the Callio SpaceLab environment to the selected earthbound research topics and applications of space exploration.

1) Joutsenvaara, J. et al. The deep underground Callio SpaceLab, Finland - Sustainable living, sustaining life. EGUGA EGU21-14129 (2021).

2) Jalas, P. et al. Callio Lab, a new deep Underground Laboratory in the Pyhäsalmi mine. in Journal of Physics: Conference Series vol. 888 (2017).

3) Mäki, T. et al The Vihanti-Pyhäsalmi VMS Belt. in Mineral Deposits of Finland 507–530 (Elsevier Inc., 2015). doi:10.1016/B978-0-12-410438-9.00020-0.

4) Oulu Mining School University of Oulu. https://www.oulu.fi/en/university/faculties-and-units/faculty-technology/oulu-mining-school.

5) Hugger crusher. University of Oulu (2020).

 

How to cite: Joutsenvaara, J., Holma, M., Hynynen, I., Kotavaara, O., and Puputti, J.: Callio Spacelab - An underground laboratory for future exploration and analogue missions in Finland, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10308, https://doi.org/10.5194/egusphere-egu22-10308, 2022.

Data from martian rovers and martian meteorites suggest the presence of ore minerals on Mars (eg. pyrite, chalcopyrite, pentlandite). Three spectrometers: CRISM (The Compact Reconnaissance Imaging Spectrometer for Mars; spectral range 0.4-3.9 µm) onboard Mars Reconnaissance Orbiter (MRO), OMEGA (Observatoire pour la Mineralogie, l'Eau, les Glaces et l; Activité, 0.4 - 5.1 µm ) and PFS (Planetary Fourier Spectrometer, 1.3-45.0 µm) onboard Mars Express (MEX) operate in near infrared (NIR) spectrum and provide information on the mineral composition of Mars but none of them is yet capable to efficiently identify sulfides. Detecting sulfide ore deposits is difficult in NIR due to spectral interferences with silicates. Due to the limited in-situ measurements by the Opportunity, Spirit, Curiosity, and Perseverance rovers, Mars mineralogical studies must be supported by studies of terrestrial analogs. One example is the Rio Tinto area in Andalusia, Spain, which hosts the largest known volcanogenic massive sulfide deposits on Earth. In this area, we analyzed satellite images in the infrared spectrum (ASTER, Landsat 8). We will compare these results to mineralogical data we will retrieve in the field during envisaged geological mapping in Spring 2022. By establishing our test field for remote sensing of sulfide deposits in a PFA site on Earth, we will be able to determine abundance thresholds for the detection of major sulfide phases on Mars and identify their key spectral features. Our results will help in 1) more efficient use of the current NIR Martian spectrometers to detect ore minerals, 2) designing new space instruments optimized for ore detection to include in future missions to Mars such as one developed at the Institute of Geological Sciences and the Space Research Centre of the Polish Academy of Sciences called MIRORES (Martian far-IR ORE Spectrometer).

Acknowledgments: The presented research are supported by National Science Centre of Poland project OPUS19 no. 2020/37/B/ST10/01420 and Europlanet2024-research infrastructure grant no. 20-EPN2-020.

How to cite: Ciazela, M., Ciazela, J., Pieterek, B., and Marciniak, D.: The use of infrared remote sensing to prospect ore deposits on Mars. Preliminary results from a planetary field analog in the Rio Tinto mining area in Spain, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10325, https://doi.org/10.5194/egusphere-egu22-10325, 2022.

EGU22-6113 | Presentations | GI3.1

EuroMoonMars Etna Campaign 2021: Logistics and Mission Protocol

Leander Schlarmann, Anouk Ehreiser, Kevin McGrath, Gary Brady, Chirayu Mohan, Hannah Reilly, Patrycja Lakomiec, Gaia De Palma, Christoph Hönes, Yke Rusticus, Bernard Foing, and Armin Wedler

The EuroMoonMars Etna campaign (EMM-Etna) took place on Mt. Etna in Sicily between the 6th and 11th of July 2021. The scouting campaign was organised by ten students of the International Lunar Exploration Working Group (ILEWG) EuroMoonMars program [1-3] in preparation for the DLR ARCHES (Autonomous Robotic Networks to Help Modern Societies) campaign and the ExoMars launch in 2022. During the ARCHES campaign on Mt. Etna in the summer of 2022, a team of robotics engineers will test various moon landing scenarios to show the capabilities of heterogeneous, autonomous, and interconnected robotic systems [4]. For the EMM-Etna campaign, the team simulated the landing of the REMMI Rover [5] on Mt. Etna as a Mars-analogue site, using a 360-degree remote-controlled camera holder to replicate a panoramic camera. Furthermore, samples were collected and analysed using an Ocean Optics UV-Vis-NIR spectrometer, a Field Raman, and a portable microscope. When working with a team of scientists and engineers the planning and organisation of the campaign are vital. Therefore, every crew member had their distinctive role during the mission, starting from being responsible for individual instruments or the outreach during the campaign to roles such as planner and data officer. Additionally, a mission protocol for the operational steps of the landing of the rover in the volcanic environment was implemented to assure smooth operation in the field.

References:

[1]          https://moonbasealliance.com/ilewg

[2]          https://euromoonmars.space/

[3]          H. Reilly et al. "Instruments Operations, Science and Innovation in Expedition Support: EuroMoonMars-Etna campaign 2021", European Planetary Science Congress 2021, online, 13–24 Sep 2021, EPSC2021-848, https://doi.org/10.5194/epsc2021-848, 2021.

[4]          M. J. Schuster et al. "The ARCHES Space-Analogue Demonstration Mission: Towards Heterogeneous Teams of Autonomous Robots for Collaborative Scientific Sampling in Planetary Exploration", IEEE Robotics and Automation Letters 5.4 (2020): 5315-5322.

[5]          C. Mohan et al. "Rover testing for lunar science and innovation", European Planetary Science Congress 2021, online, 13–24 Sep 2021, EPSC2021-850, https://doi.org/10.5194/epsc2021-850, 2021.

 

How to cite: Schlarmann, L., Ehreiser, A., McGrath, K., Brady, G., Mohan, C., Reilly, H., Lakomiec, P., De Palma, G., Hönes, C., Rusticus, Y., Foing, B., and Wedler, A.: EuroMoonMars Etna Campaign 2021: Logistics and Mission Protocol, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6113, https://doi.org/10.5194/egusphere-egu22-6113, 2022.

EGU22-611 | Presentations | GI3.1

First results and Lessons Learned of CHILL-ICE 2021 Field Campaign

Marc Heemskerk, Charlotte Pouwels, Thor Atli Fanndal, Sabrina Kerber, Árni B. Stefánsson, Esther Konijnenberg, Jaap Elstgeest, and Benedetta Cattani

During the summer of 2021, the first CHILL-ICE analogue campaign was held in and around the Stefánshellir Lava tube in the Hallmundarhraun lava field, in the West of Iceland. Here we present some of the campaign results of the two analogue missions that made up this research campaign.

After initial EuroMoonMars campagns in 2018 and 2020, the project group, named CHILL-ICE (Construction of a Habitat Inside a Lunar-analogue Lavatube - Iceland) was founded. More than 30 young researchers, students, and collaborators from 16 countries, worked closely together and two short analogue astronaut missions were held. These missions were the main goal of this campaign, where in the future also a stronger focus on the robot-human interfaces and exploration of subsurface cave systems is planned.