Water temperature is one of the key factors controlling aquatic ecosystems and influencing physical, chemical and biological processes. Detailed observations of spatial and temporal patterns in water temperature are important for assessing e.g. variations in thermal refugia, impacts of climate change and for developing appropriate management strategies. Freshwater  temperatures are still mostly analysed based on single point measurements, but these do not reflect the spatial thermal variability within waterbodies (i.e. stream and lake) and therefore could lack information on thermal refugia. 2-D images of freshwater temperature in varying spatial resolution are increasingly obtained by space- and airborne methods such as UAV (unmanned aircraft vehicles). While these UAV methods offer the necessary spatial resolution at the surface, they require in situ measurements to obtain absolute temperature values and don’t provide information on vertical thermal variability. Approaches that bridge this gap do exist (e.g. fibreoptic cables), but high demand on resources and high costs limit widespread use.

The aim of this work was to develop a low-cost, custom-build, fully flexible 3-D temperature sensor system that can be used for calibration and validation of thermal UAV observations, but also adds information on water temperature with depth. The design of our floating sensor system (with a maximum of 72 sensors) offers high flexibility in horizontal/vertical spacing and logging time intervals (ms to h). Here we present the first results of our prototype, which was calibrated using Solinst Leveloggers (accuracy ± 0.05ºC) and tested under various ambient conditions, both in the laboratory and in a lab-in-field experiment in a relatively shallow lake (maximum measurement depth of 1.50 m) in NE Scotland. We also evaluated the use of this system with UAV imagery at the lake.

The results show a quick response of the individual sensors to temperature changes and indicate suitability of the system for validating and calibrating thermal UAV images. For a set-up with 12 vertical arrays (6 sensors at different depths for each array) and arranged as a grid, preliminary data indicated the value for a 3-D approach as not all thermal patterns at depth were captured by surface measurements. Next, the transferability of the sensor system to a stream will be tested and applied to a stream water management case. Together with UAV thermal imagery, the new sensor system could have the potential for a wide range of research and management applications (e.g. thermal habitats, groundwater upwelling, infiltration of cooling water).

How to cite: Loerke, E., Wilkinson, M. E., Pohle, I., Drummond, D., and Geris, J.: A new low-cost approach to 3-D water temperature monitoring, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1120, https://doi.org/10.5194/egusphere-egu21-1120, 2021.

International attempts to limit greenhouse gas (GHG) concentrations, aimed at stabilizing human induced climate change, require a detailed understanding of the current and potential future role of forests to sequester carbon. Accurate, high frequency and reliable measurements are therefore vital in developing effective mitigation strategies and help to improve understanding of the other ecosystem services provided by forests which are valued by society. However, forests are typically located in remote, rural environments which can make regular access for surveyors and other forest scientists challenging and logistically difficult. In 2020, Forest Research worked in partnership with the UK government’s Department for Environment, Food and Rural Affairs (Defra) and Vodafone to explore how Internet of things (IoT) technology can be used to improve environmental and forest monitoring and to test its suitability at remote rural locations in the UK. A pilot study which ran at Forest Research’s two contrasting long-term carbon flux sites, Alice Holt (Hampshire) and Harwood (Northumberland) used IoT technology to measure and transmit high frequency growth and environmental data over the course on an entire growing season. Tree growth sensors (automated dendrometers) and a range of other environmental sensors (e.g. air temperature and  humidity, soil moisture) attached to the trees and in the soil (nine replicates per site), were connected to the Vodafone Narrowband-IoT (NB-IoT) network. Data was uploaded every 15 minutes to a Grafana based online web portal, providing researchers with near real time access to the data.  Here we present results from these two sites, details of the hardware used in these new devices and evaluation of their performance during this pilot study.

How to cite: Wilkinson, M., Bell, M., Baer, T., and Xenakis, G.: Measuring and monitoring trees and forests using a novel IoT approach, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-887, https://doi.org/10.5194/egusphere-egu21-887, 2021.

Over the past years, simple acoustic drop detectors have been developed for different objectives. The core of these detectors were standard piezoelectric elements. For some applications, such as simply counting drops, not much signal processing is needed. For other applications, however, such as measurement of drop energy, which would allow for estimation of drop sizes as well, careful signal processing is needed. For this purpose, we have developed a shield, or “Wing” that can be plugged into an Adafruit Feather (https://www.adafruit.com/feather), which we call DisdroWing. This board includes a high-end operational amplifier and a fast analogue to digital converter. With this board, the user can experiment and implement specific applications, such as rain/no rain detection, hail detection, or drop energy. The design of the DisdroWing is publicly available and can also be purchased fully assembled.

How to cite: van de Giesen, N., Hut, R., and van der Lubbe - Sanjuan, D.: Open source hardware for counting and measuring raindrops, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2289, https://doi.org/10.5194/egusphere-egu21-2289, 2021.

Off-the-shelf portable automatic water samplers, such as the 6712 full-size portable sampler (Teledyne ISCO, Lincoln, USA), are often used in remote locations to collect precipitation or streamwater for subsequent analysis of deuterium and oxygen-18.  The bottles inside these automatic samplers remain open during the full duration of sampler deployment and the collected water samples can thus be subjected to evaporation and vapor exchange.  Both processes are known to alter the isotope composition of the water sample, and thus the questions arise as to 1) how credible the isotope measurements from automatically collected water samples are and 2) how can these isotope effects in the automatic water sampler be reduced?

We evaluated these questions through laboratory and field experiments in which we quantified the change in isotope composition in the water samples with respect to ambient conditions (air temperature and relative humidity), storage duration, and sample volume.  We found that isotope fractionation in the water samples was substantial under very warm and dry condition, when sample volumes are small or when sample storage exceeded 10 days.  To address these problems, we have designed an evaporation protection method which modifies autosampler bottles using a syringe housing and silicone tube.  We performed paired experiments with open vs. evaporation-protected bottles in Teledyne ISCO 6712 full-size portable samplers to evaluate our design.  We could show that the evaporation protection successfully reduced isotope fractionation in the water samples for storage durations of up to 24 days and for a wide range of ambient conditions; e.g., while deuterium concentrations in the water samples in open bottles changed by ca. 3‰ under very warm and dry conditions, no isotope effect was measured in the bottles equipped with the evaporation protection. Because our design is very cost efficient it can easily be implemented to upgrade Teledyne ISCO’s 6712 full-size portable samplers or other similar devices for collecting more reliable isotope data.

How to cite: von Freyberg, J., Knapp, J. L. A., Rücker, A., Studer, B., Zappa, M., and Kirchner, J. W.: An easy-to-use, low-cost evaporation protection to collect more reliable stable water isotope data with Teledyne ISCO portable samplers, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2764, https://doi.org/10.5194/egusphere-egu21-2764, 2021.

Sewage overflows in headwater catchments are critical, mostly not well monitored point sources for many pollutants such as oxygen depleting substances, pharmaceuticals or heavy metals. The outlets are often located at places where no connection to the power grid is available, hence it is often necessary to provide deployed sensors or sampling devices with mobile power sources like car-batteries. In addition, autosamplers or on-line sensors are expensive devices. For these reasons, a proper monitoring strategy, including water quality parameters in these structures is often complicated to implement and from an economical point of view not reasonable. Therefore, we combined two low-budget DIY devices, a modified Zurich sequential sampler for time-discrete rainfall samples and Stream Temperature, Intermittency, and Conductivity loggers (STIC), to build a low-budget monitoring system being able to take time-discrete samples from sewage overflow. Our modified sampler collects 12 samples in a row, with variable volumes from 0.25 to 0.5 L. In each bottle a STIC was implemented. The STICs start to measure a conductivity higher than zero as soon as water starts to flow into the bottle. This allows for a clear assignment between sample and time. We called this sampler the Sewage Overflow Monitoring Sampler (SOMS).

Though the probe volume and the time period for sampling is strongly limited, concentration variations, including peak concentrations, in sewage overflows are expected to be measured right at the beginning of an event (first flush) and should be therefore covered by the sampler. First laboratory tests were successful. In the next step the monitoring system will be implemented on a field side.

Depending on the scientific question of the study, the SOMS can be complemented in the field by either another STIC logger or a pressure probe. The STIC logger is located at the bottom of the canal. This allows the detection of the duration of the overflow event. By installing a pressure probe the discharge can be approximated as long as gradient and the geometry of the canal is known.

How to cite: Spill, C., Ditzel, L., Brumm, N., Böhm, J., and Gassmann, M.: Low-Budget Sewage Overflow Monitoring, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8325, https://doi.org/10.5194/egusphere-egu21-8325, 2021.

Water vapour observations represent an important input e.g. for predicting mesoscale initiation of convective precipitation or estimating evapotranspiration. E-band commercial microwave links (CMLs), which are increasingly used in cellular backhaul, might be used as unintentional water vapour sensors accessible remotely from a network operation centre. E-band CMLs operate at frequencies between 71 and 86 GHz where water vapour causes substantial attenuation of electromagnetic waves. This attenuation can be related to water vapour density along a CML path, nevertheless, it has to be properly separated from other sources of attenuation, especially rainfall-induced attenuation, and wet antenna attenuation caused by wet surface of antenna radomes. Moreover, the relation between attenuation and water vapour density is also dependent on temperature (Fencl et al., 2020).

This contribution evaluates capability to estimate water vapour density on a 4.86 km long full-duplex CML being operated within cellular backhaul at frequencies 73.5 GHz and 83.5 GHz. Three rain gauges are deployed along its path, two of them being equipped with an air humidity sensor. The evaluation period is between August to December 2018. The results show that estimation of water vapour density is feasible when there is now rain and antenna radomes are dry, which is only about 50% of time. Estimated water vapour density during dry weather is highly correlated with humidity observations (r = 0.7). The highest correlations are observed during summer season (r = 0.9) and lowest during December (r = 0.3) when amplitude of water vapour fluctuations are small. In contrast, mean absolute error is highest during August (approx. 1 g/m³) and lowest in December (0.2 g/m³). Most of the outliers were encountered during October, probably due to multipath inferences occurring during clear-sky conditions.

Unintentional sensing of water vapour density with E-band CMLs is feasible by sufficiently (several kilometres) long CMLs. Currently, 20 % of new CML deployments are operated E-band. E-band CMLs might thus greatly increase continental coverage of water vapour ground observations.

Fencl, M., Dohnal, M., Valtr, P., Grabner, M. and Bareš, V.: Atmospheric observations with E-band microwave links – challenges and opportunities, Atmospheric Measurement Techniques, 13(12), 6559–6578, https://doi.org/10.5194/amt-13-6559-2020, 2020.

How to cite: Fencl, M. and Bares, V.: Water vapour monitoring with E-band microwave links of cellular backhaul, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8384, https://doi.org/10.5194/egusphere-egu21-8384, 2021.

Compared to horizontal components, the vertical components of ocean currents are generally very weak (a few mm/s) in all oceanic regions of the world. Due to their major role in the vertical distribution of physical and biogeochemical properties of sea water, their extended knowledge is of utmost importance for oceanographers. However, their in-situ measurement represents a real technical challenge, even using sophisticated instruments such as ADCPs.

As a complement to the ADCP method presented in another session (Comby et al.), we have developed an original alternative instrument, called the VVP (Vertical Velocity Profiler). It was inspired by several published works which exploit the difference between the real vertical speed Wr of a submarine glider (~dP/dt, from the onboard pressure sensor) and its theoretical vertical speed Wth extracted from a flight model. The oceanic vertical speed Woc is thus expressed by the simple difference Woc = Wr - Wth at any  point in the water column.

The very first prototype of the VVP consisted of a float and a friction disc, ballasted to sink at a very low speed (~ 0.1 m / s) and dragged down to the desired depth by a dead-weight which was automatically released after a suitable delay. The release system was developped in-house (patent filled in March 2020), based on a textured insert trapped in a volume of ice melting at controlled speed. Since then, the concept of the profiler has evolved considerably. The last design uses an electric thruster that drives the profiler down to a predefined setpoint depth. Once the depth is reached, the thruster is stopped and the profiler then rises slowly (~0.1 m/s) to the surface under the sole effect of its slightly positive buoyancy. The mechanical balance between buoyancy and hydrodynamic drag results in a constant vertical speed of ascent in water at rest. Any deviation from this constant speed is then interpreted as an oceanic  vertical velocity signal. This new design allows a very large number of consecutive profiles to be collected, the number of descent-ascent cycles and the setpoint depth being programmed and controlled using an ARDUINO microcontroller board. The selected Li-Io battery allows for several hours of continuous profiling.  When on surface, the profiler is currently located by a commercial GPS tracker integrated into the electronic case. The vertical velocity of the profiler is accurately measured at  high frequency (2Hz) thanks to the fast-response pressure sensor of the onboard RBR-CONCERTO autonomous CTD, which also measures the sea water density involved in  drag and buoyancy.

Trials both in deep pool and in the field are scheduled in spring 2021 in order to refine the prototype design and to definitely set the flight model parameters. This development benefits from CNES (Centre National d'Etudes Spatiales) financial support in the framework of the BIOSWOT international program.

How to cite: Fuda, J.-L., Barrillon, S., Doglioli, A., Petrenko, A., Gregori, G., Tzortzis, R., Comby, C., Thyssen, M., Lafont, M., Bhairy, N., Malengros, D., Guillemain, D., and Grenz, C.: A new approch for measuring ocean vertical velocities, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9371, https://doi.org/10.5194/egusphere-egu21-9371, 2021.

Measuring water transparency allows us to monitor the water body's environmental status. One parameter to estimate water transparency is the light diffuse attenuation coefficient (Kd). This coefficient is of particular interest in water quality monitoring programs.

The Kd describes the light extinction as function as the depth of downwelling irradiance, Ed. However, self-shading by the instrument itself can cause errors in Ed estimations. To avoid this effect, relative complex structures must be required to install the sensors that limit the vertical resolution of Ed measurements. Here we propose to use optical sensors in an annular-shape distribution to mitigate these limitations. For this, we introduce a new concept: the annular irradiance, Ea. We first compute the optimal angle to avoid self-shading while maximizing the light captured by the sensor. Second, we assess the robustness of the corresponding diffuse attenuation coefficient, Ka, in different scenarios of water types, solar angle and cloud coverage. Finally, we correlate Ka measurements with Kd at PAR region, and we derive empirical functions from translating Ka to Kd measurements.      

This new coefficient is the basis of the new generation of the KdUINO instrument  (Bardaji et al., 2016) as a KduSTICK, which estimates the near-surface light extinction coefficient based on Ka measurements. Since the design of the instrument avoids self-shading, the device is expected to be particularly useful in those underwater environments where high vertical Ed resolution is required.

Furthermore, instruments based on this light-sensing approach are much simpler to deploy and maintain, and it is possible to design low-cost and Do-It-Yourself (DIY) versions. All these features facilitate its use for non-academic users, making the KduSTICK an optimal instrument to be used in Citizen Science water quality monitoring programs.

How to cite: Rodero, C., Bardaji, R., Salvador, J., Olmedo, E., and Piera, J.: Underwater annular irradiance: New concept to measure the light diffuse attenuation coefficient through the KduSTICK, a Do-It-Yourself device, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9421, https://doi.org/10.5194/egusphere-egu21-9421, 2021.

Monitoring ephemeral and intermittent streams is a major challenge in hydrology. While direct field observations are best to detect spatial patterns of flow persistence, on site inspections are time and labor intensive and may be impractical in difficult-to-access environments. Motivated by latest advancements of digital cameras and computer vision techniques, in this work, we describe the development and application of a stage-camera system to monitor the water level in ungauged headwater streams. The system encompasses a consumer grade wildlife camera with near infrared (NIR) night vision capabilities and a white pole that serves as reference object in the collected images. Time-lapse imagery is processed through a computationally inexpensive algorithm featuring image quantization and binarization, and water level time series are filtered through a simple statistical scheme. The feasibility of the approach is demonstrated through a set of benchmark experiments performed in controlled and natural settings, characterized by an increased level of complexity. Maximum mean absolute errors between stage-camera and reference data are approximately equal to 2 cm in the worst scenario that corresponds to severe hydrometeorological conditions. Our preliminary results are encouraging and support the scalability of the stage camera in future implementations in a wide range of natural settings.

How to cite: Noto, S., Tauro, F., Petroselli, A., Apollonio, C., Botter, G., and Grimaldi, S.: Continuous water level monitoring using time-lapse imagery, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10906, https://doi.org/10.5194/egusphere-egu21-10906, 2021.

Fine sediment supply to floodplains and coastal areas is extremely important for nutrient transport, global biogeochemical cycles, water quality and pollution in riverine, coastal and marine ecosystems. Monitoring of suspended sediment in rivers with current sensors is challenging and expensive, and most monitoring setups are restricted to few single point measurements. To better understand the spatial heterogeneity of fine sediment production and transport in river systems there is a need for new smart water turbidity sensing that is multisite and at the same time accurate and affordable.

We developed an affordable but reasonably accurate turbidity sensor, that is suitable for distributed sensing with a multitude of sensors across catchments. Our turbidity sensor is much cheaper than existing options of comparable quality. It works by illuminating a sediment-laden water sample with an 860nm IR LED and detects the amount of light scattered at two different angles (with respect to the LED) using light-to-frequency converters. It also incudes an internal temperature sensor and data storage on an SD card. We are also planning to include a water pressure sensor, a GPS module, a more compact and durable design with a printed circuit board, and the option of remote data transmission via LoRa.

Here, we present the results of two experiments with the developed new sensor: (1) a calibration test using formazin (4000 NTU) dilutions to evaluate which detector angles work best in the 0-4000 NTU range, how ambient light affects the results, and if focusing lenses and high-pass filters increase the sensor’s accuracy; (2) a laboratory test with various sediment types and concentrations mixed in a large water tank to compare replicates of our sensors (six in total) to different commercially available turbidity probes. Our results show that a high accuracy in the 0-4000 NTU range can be achieved with our low cost, low power sensor.

The new turbidity sensor will allow us to localise sediment sources and sinks in catchments, i.e. where and when fine sediment is produced, transported and deposited across entire catchments. We will be able to observe the variability in suspended sediment fluxes in glacial streams (the development, expansion and collapse of subglacial channels), along river networks with different local sources (effect of tributary inputs and hillslope landslides), concentration variability due to flow-bed interactions (influence of river bed morphology and grain size), and asses the activation of erosion by rainfall across the multiple potential sediment sources of a catchment. The developed sensor will enable the development of distributed measurement setups, which hopefully can address many other complex challenges related to the spatially heterogeneous processes of sediment activation and transport. This project lays a foundation to explore water turbidity sensing in other global environmental applications in the future, such as soil erosion, sediment trapping behind dams, lake monitoring, and ecological studies.

How to cite: Molnar, P., Droujko, J., and Floriancic, M.: A Low-Cost Turbidity Sensor for Deployment in Rivers, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13337, https://doi.org/10.5194/egusphere-egu21-13337, 2021.

Streamflow measurement and prediction are important for proper water resources management. In this case, the water resources problem is drought in the Coastal Mountains of British Columbia, Canada, where a village is drawing drinking water from a mountain stream. Because of challenges with other flow measurement methods in streep turbulent streams, salt dilution gauging is the best way to measure streamflow, but it is labour intensive.

To advance progress towards the singularity, an intelligent automated salt dilution gauging system was deployed, and provides good results, but some disturbances occur due to the presence of a tributary and a drinking water intake. We show how this noise can be turned into signals and discuss a range of other signals that together provide input for the discharge record.

How to cite: Weijs, S. and Eugeni, S.: Bring the noise: Piecing together a discharge record from an automated salt dilution gauging setup and various other information sources, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14324, https://doi.org/10.5194/egusphere-egu21-14324, 2021.

Several studies have been carried out to evaluate image-based solutions for velocity measurement and discharge determination in river. However, these studies are limited because it is difficult to know the reference surface velocity field accurately. These data are usually extrapolated from measurement within the water column or integrated over a cross-section to determine the discharge to be compared with a reference, which is uncertain itself. Measurement uncertainties are difficult to quantify and cannot be neglected usually.

The only solution that arises to get a flow with a known surface velocity reference is synthetic imaging: we generate artificial images on which particles movements are known everywhere. However, these generators must allow a comparison between simulations and measurements for a wide range of conditions representative of the situations observed in the natural environment. Several Synthetic Image Generators have been designed for laboratory PIV but the generated images are made of white particles moving on a dark background. Such images are not representative of river applications with turbulence figures, foam, debris, sunlight effects but also some homogeneous areas with poor contrast where we can sometimes see the river bed through.

We propose a novel method to generate images from a synthetic river scene with accurate surface velocity references. It is based on the 3D computer graphics tool Blender which integrates a dedicated fluid simulation tool, Mantaflow. Blender allows many different configurations by playing on the modeling of the river, the surrounding objects, the textures and optical properties of the materials but also on the lighting and the camera settings and position. Mantaflow is then used to model and extract the characteristics (velocities, positions in time) of a flow that looks similar to real-life situations. The first synthetic videos obtained were used to study the sensitivity of the velocity results to the image-based velocimetry algorithm, its parameters and user choices.

How to cite: Bodart, G., Le Coz, J., Jodeau, M., and Hauet, A.: Generating videos of synthetic river flow for the evaluation of image-based techniques for surface velocity determination, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10778, https://doi.org/10.5194/egusphere-egu21-10778, 2021.

The work reported here builds upon a previous pilot study by the author on ANN-enhanced flow rating (Schmid, 2020), which explored the use of electrical conductivity (EC) in addition to stage to obtain ‘better’, i.e. more accurate and robust, estimates of streamflow. The inclusion of EC has an advantage, when the relationship of EC versus flow rate is not chemostatic in character. In the majority of cases, EC is, indeed, not chemostatic, but tends to decrease with increasing discharge (so-called dilution behaviour), as reported by e.g. Moatar et al. (2017), Weijs et al. (2013) and Tunqui Neira et al.(2020). This is also in line with this author’s experience.

The research presented here takes the neural network based approach one major step further and incorporates the temporal rate of change in stage and the direction of change in EC among the input variables (which, thus, comprise stage, EC, change in stage and direction of change in EC). Consequently, there are now 4 input variables in total employed as predictors of flow rate. Information on the temporal changes in both flow rate and EC helps the Artificial Neural Network (ANN) characterize hysteretic behaviour, with EC assuming different values for falling and rising flow rate, respectively, as described, for instance, by Singley et al. (2017).

The ANN employed is of the Multilayer Perceptron (MLP) type, with stage, EC, change in stage and direction of change in EC of the Mödling data set (Schmid, 2020) as input variables. Summarising the stream characteristics, the Mödling brook can be described as a small Austrian stream with a catchment of fairly mixed composition (forests, agricultural and urbanized areas). The relationship of EC versus flow reflects dilution behaviour. Neural network configuration 4-5-1 (the 4 input variables mentioned above, 5 hidden nodes and discharge as the single output) with learning rate 0.05 and momentum 0.15 was found to perform best, with testing average RMSE (root mean square error) of the scaled output after 100,000 epochs amounting to 0.0138 as compared to 0.0216 for the (best performing) 2-5-1 MLP with stage and EC as inputs only.    

References

Moatar, F., Abbott, B.W., Minaudo, C., Curie, F. and Pinay, G.: Elemental properties, hydrology, and biology interact to shape concentration-discharge curves for carbon, nutrients, sediment and major ions. Water Resources Res., 53, 1270-1287, 2017.

Schmid, B.H.: Enhanced flow rating using neural networks with water stage and electrical conductivity as predictors. EGU2020-1804, EGU General Assembly 2020.

Singley, J.G., Wlostowski, A.N., Bergstrom, A.J., Sokol, E.R., Torrens, C.L., Jaros, C., Wilson, C.,E., Hendrickson, P.J. and Gooseff, M.N.: Characterizing hyporheic exchange processes using high-frequency electrical conductivity-discharge relationships on subhourly to interannual timescales. Water Resources Res. 53, 4124-4141, 2017.

Tunqui Neira, J.M., Andréassian, V., Tallec, G. and Mouchel, J.-M.: A two-sided affine power scaling relationship to represent the concentration-discharge relationship. Hydrol. Earth Syst. Sci. 24, 1823-1830, 2020.

Weijs, S.V., Mutzner, R. and Parlange, M.B.: Could electrical conductivity replace water level in rating curves for alpine streams? Water Resources Research 49, 343-351, 2013.

How to cite: Schmid, B.: An improvement to the ANN-enhanced flow rating method, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-221, https://doi.org/10.5194/egusphere-egu21-221, 2021.

Highly intermittent rivers are widespread on the Tibetan Plateau and deeply impact the ecological stability and social development downstream. Due to the highly intermittent rivers are small, seasonal variated and heavy cloud covered on the Tibetan Plateau, their distribution location is still unknown at catchment scale currently. To address these challenges, a new method is proposed for extracting the cumulative distribution location of highly intermittent river from Sentinel-1 time series in an alpine catchment on the Tibetan Plateau. The proposed method first determines the proper time scale of extracting highly intermittent river, based on which the statistical features are calculated to amplify the difference between land covers. Subsequently, the synoptic cumulative distribution location is extracted through Random Forest model using the statistical features above as explanatory variables. And the precise result is generated by combining the synoptic result with critical flow accumulation area.  The highly intermittent river segments are derived and assessed in an alpine catchment of Lhasa River Basin. The results show that the the intra-annual time scale is sufficient for highly intermittent river extraction. And the proposed method can extract highly intermittent river cumulative distribution locations with total precision of 0.62, distance error median of 64.03 m, outperforming other existing river extraction method.

How to cite: Fei, J. and Liu, J.: Extracting the cumulative distribution location of highly intermittent river from Sentinel-1 time series in an alpine catchment on the Tibetan Plateau, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4040, https://doi.org/10.5194/egusphere-egu21-4040, 2021.

Splosh, gurgle, burble are all terms that can be used to describe how a river sounds as we stand on the bank. We have developed a new approach that uses the passive sound generated by a river, to gauge the current stage of the river, and generate (sono)hydrographs from the safety of the river bank. Our approach offers a cost-effective, power-efficient and flexible means to install flood monitors. We have developed a method of how to take the sound from around a river and translate it into a useful gauging tool without the need to listen to individual recordings. Using an internet of things approach we have developed a system of sound monitors that can be placed anywhere in the vicinity of a river. We aim to target the lesser studied parts of a river catchment, the headwaters, which are often data scarce environments. These environments are an opportunity to identify the real time responses of sub-catchments. The ultimate goal of our research is to enable community level flood monitoring, in areas that may be susceptible to river flooding, but are not yet actively gauged.

We hypothesise that the sound generated by a river is a direct response to the obstacles found within the channel and the turbulence they cause. Sound is generated by the increase of energy available in the channel, being transformed into sound energy through turbulence generating structures, i.e. boulders. Data gathered over a winter season from several rivers in the North East of England, during Storm Ciara and Dennis, has shown sound to be a reliable method for determining rapid changes in river stage and is comparable to what the official Environment Agency gauges measured. Through an innovative approach, we have begun to understand the limits on sound data and the calibration of sound to the channel properties. Utilising a 7.5 m wide flume at a white water course we have recreated controlled environments and simulated different discharges and their effect on sound.

Overall, we have found that sound is an opportunity to be taken to measure river stage in areas that are seldom studied. We have identified that sound works during extreme conditions, and being placed on the banks of the channel our monitors have a lower risk of being damaged during storm events and are easy and safe to install. We present the first means of using sound from a river to actively gauge a river and the full workflow from collection, analysis and dissemination of results.

How to cite: Osborne, W. A., Hodge, R., Love, G., Hawkin, P., and Hawkin, R.: Innovative method for gathering river stage data using only the sound of the water, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-136, https://doi.org/10.5194/egusphere-egu21-136, 2021.

Optical sensors coupled with image velocimetry techniques are becoming popular for river monitoring applications. In this context, new opportunities and challenges are growing for the research community aimed to: i) define standardized practices and methodologies; and ii) overcome some recognized uncertainty at the field scale. At this regard, the accuracy of image velocimetry techniques strongly depends on the occurrence and distribution of visible features on the water surface in consecutive frames. In a natural environment, the amount, spatial distribution and visibility of natural features on river surface are continuously challenging because of environmental factors and hydraulic conditions. The dimensionless seeding distribution index (SDI), recently introduced by Pizarro et al., 2020a,b and Dal Sasso et al., 2020, represents a metric based on seeding density and spatial distribution of tracers for identifying the best frame window (FW) during video footage. In this work, a methodology based on the SDI index was applied to different study cases with the Large Scale Particle Image Velocimetry (LSPIV) technique. Videos adopted are taken from the repository recently created by the COST Action Harmonious, which includes 13 case study across Europe and beyond for image velocimetry applications (Perks et al., 2020). The optimal frame window selection is based on two criteria: i) the maximization of the number of frames and ii) the minimization of SDI index. This methodology allowed an error reduction between 20 and 39% respect to the entire video configuration. This novel idea appears suitable for performing image velocimetry in natural settings where environmental and hydraulic conditions are extremely challenging and particularly useful for real-time observations from fixed river-gauged stations where an extended number of frames are usually recorded and analyzed.

References

Dal Sasso S.F., Pizarro A., Manfreda S., Metrics for the Quantification of Seeding Characteristics to Enhance Image Velocimetry Performance in Rivers. Remote Sensing, 12, 1789 (doi: 10.3390/rs12111789), 2020.

Perks M. T., Dal Sasso S. F., Hauet A., Jamieson E., Le Coz J., Pearce S., …Manfreda S, Towards harmonisation of image velocimetry techniques for river surface velocity observations. Earth System Science Data, https://doi.org/10.5194/essd-12-1545-2020, 12(3), 1545 – 1559, 2020.

Pizarro A., Dal Sasso S.F., Manfreda S., Refining image-velocimetry performances for streamflow monitoring: Seeding metrics to errors minimisation, Hydrological Processes, (doi: 10.1002/hyp.13919), 1-9, 2020.

Pizarro A., Dal Sasso S.F., Perks M. and Manfreda S., Identifying the optimal spatial distribution of tracers for optical sensing of stream surface flow, Hydrology and Earth System Sciences, 24, 5173–5185, (10.5194/hess-24-5173-2020), 2020.

How to cite: Dal Sasso, S. F., Pizarro, A., Pearce, S., Maddock, I., Perks, M. T., and Manfreda, S.: Seeding metrics for image velocimetry performances in rivers, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9229, https://doi.org/10.5194/egusphere-egu21-9229, 2021.

In recent years, technological advances have been observed in environmental monitoring field, leading to a rapid spread of innovative technologies overcoming many historical challenges. In river monitoring field the use of image-based techniques provides non-intrusive measurements ensuring the best safety conditions for operators. The most used optical methods are the Large-Scale Particle Image Velocimetry (LSPIV) and the Large-Scale Particle Tracking Velocimetry (LSPTV).

In LSPIV and LSPTV techniques a floating tracer is introduced on the water surface and its motion is recorded by commercial devices (e.g. digital cameras). Resulting videos are then processed by free and open source software which applies a statistical cross-correlation analysis to provide the instantaneous surface velocity field.

The aim of this work is to investigate the performance of the most widely used LSPIV software in estimating the surface velocity field taking into account the presence of turbulent structures. Indeed a typical feature of natural river is the presence of turbulent eddies which makes the tracer patterns above the water surface difficult to predict. The evaluation of tracer particle displacement is further complicated by the negative phenomenon of aggregation; it influences cross-correlation causing an incorrect estimation of the velocity vectors.

The study of the hydraulic turbulence of a natural river has been tackled from a numerical point of view. PANORMUS (Parallel Numerical Open-Source Model for Unsteady Flow Simulations) package (Napoli, 2011) has been used by adopting a LES (Large Eddy Simulation) scheme. PANORMUS is a numerical tool coded to solve the 3D momentum equations for incompressible flows (Navier-Stokes and Reynolds equations) using the Finite-Volume Method (FVM). The analyses were carried out on real cases modelled with PANORMUS-LES package. The hydraulic reconstructed domains are characterised by regular cross sections, accurately derived from real topographic survey campaigns, and low river-bed roughness (smooth concrete surface).

Synthetic sequences of tracer motion were derived from the hydraulic model and then processed by using LSPIV software.

The results of such numerical analyses have allowed an evaluation of LSPIV performance assessing the errors in terms of mean value of the surface velocity field and velocity along transverse transects.

How to cite: Alongi, F., Ciraolo, G., Napoli, E., Pumo, D., and Noto, L. V.: Large-Eddy Simulation in LSPIV techniques: the study of surface turbolence, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15468, https://doi.org/10.5194/egusphere-egu21-15468, 2021.

Water resources in Myanmar are increasingly affected by anthropogenic pressure and climate change related impacts. At the Inle Lake a unique village is located on the water in close proximity to intense fishing/farming activities. The nearby floating gardens provide invaluable resources for local communities, who are highly vulnerable to changes to water quality in the lake. Diversely, within the city of Yangon, the Kandawgyi lake is a popular recreational area which has become heavily affected by excessive algae proliferation. The deterioration of water quality Is likely caused by uncontrolled untreated wastewater, and poses a risk to the citizens. Finally, rivers such as the Pan Hlaing River, flow through industrial zones and collect waste water discharges.

Monitoring in these regions is scarce and limited to a few point-sampling locations. Local stakeholders lack adequate tools to monitor the needed parameters and are in need of reliable and updated baseline water quality data to support them in setting-up sustainable water management strategies. Tools such as aquatic drones and in-situ sensors are innovative ways of monitoring water quality and ecology that could contribute for effectively gathering valuable environmental data.

In this project, aquatic drones (both underwater and surface) were equipped with water quality sensors and cameras for low-cost and rapid assessment of surface water quality at high spatial resolution. The drones are able to navigate autonomously through way-points while collecting geo-referenced data. This study aims at field-testing of two affordable aquatic drones with sensors to map water quality parameters in different types of water systems (large lake, urban lake, river). This study reports the challenges encountered, and evaluates the resulting dataset/maps are in relation to the cost and value for the local stakeholders (ongoing research).

At the Inle Lake, results show varying concentrations of the different parameters that were measured. Low dissolved oxygen levels were found within the villages and underneath floating gardens, while chlorophyll-a and cyanobacteria levels were low across the whole lake. Underwater images show the presence of fish and provide insights into the aquatic ecosystems. At the Kandawgyi Lake, the generated water quality maps illustrate the spatial distribution of the different parameters, and two main areas of contamination could be identified (high algae content, low dissolved oxygen, high E-coli concentrations). At the Pan Hlaing river, the plotted data show degrading levels of dissolved oxygen concentrations, indicating potential effects caused by industry outlets.

The water quality maps that were generated with this data are very illustrative of the condition of the water bodies and the location of contaminations hotspots. The measurement process was accompanied by stakeholders and local universities, which contributed to stimulate capacity building and to create awareness for water quality related problems. As follow-up activities, these results will be used to draft a long-term water quality monitoring plan for local Myanmar students to continue collecting water quality data at these lakes. The detected issues are being discussed with local stakeholders, as well as the possibilities for establishing a larger scale monitoring campaign using this type of monitoring tools.

How to cite: Pedroso de Lima, R., Bogaard, T., and De Lange, R.: Mapping surface water quality in Myanmar using aquatic drones, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15531, https://doi.org/10.5194/egusphere-egu21-15531, 2021.

Soil hydraulic properties provide important information about soil behavior under unsaturated and saturated conditions. Often sampling of undisturbed soils is not possible and soil samples have to be repacked for laboratory analysis. The HYPROP® measuring system (METERgroup, Munich, Germany) is a convenient method for determination of soil water retention characteristics and unsaturated hydraulic conductivity of undisturbed soil samples. It measures the matric potential of the saturated and drying soil sample using two tensiometers placed at different depths. Although the tensiometers are based on a new design that theoretically withstands cavitation at higher tension values, they are still considered to operate in the low tension range. Since soil water retention properties in the low tension range are strongly influenced by soil structure and pore size distribution, we were interested in the changes in hydraulic properties when measured on disturbed and then repacked samples, and undisturbed soil samples. Therefore, we investigated the soil hydraulic properties of three different soil types using the evaporation method on undisturbed and repacked samples. The results provide important insights for the interpretation of the results when the collection of undisturbed samples is not possible, and for designing laboratory experiments with repacked soils.

How to cite: Pečan, U., Žvokelj, L., Ferlin, J., Zupanc, V., and Pintar, M.: Measurement of soil hydraulic properties of structured and repacked soils, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3985, https://doi.org/10.5194/egusphere-egu21-3985, 2021.

Near surface soil hydraulic conductivity is an essential parameter for various hydrological, geotechnical, and environmental-related studies. Currently, many instruments are in practice for evaluating this parameter, both in field, and laboratory. The rainfall simulator (RS) and mini disc infiltrometer (MDI) are two instruments used for the indirect estimation of hydraulic conductivity by many researchers and engineers. However, both the devices differ in their working philosophy and evaluation methodology. While the RS works by considering large soil volumes and providing a positive soil pressure, the MDI works for small sampled volumes and supply negative boundary head. Therefore, the two devices can result in varying estimates of hydraulic conductivity. In this study, a comparative assessment is carried out between the saturated hydraulic conductivity (K_s) estimates from the two instruments using laboratory experiments for two different soil textures (loam and sand). The infiltration results from the RS are analyzed using the Green-Ampt method, and from the MDI is analyzed using the Zhang's method followed by the Kutilek and Nielson method to produce K_s values. The K_s results from both the instruments are compared with the values obtained using the laboratory falling-head permeameter test. A one-way ANOVA and the Fisher’s Least Significant Difference (LSD) test as a posthoc test are carried out to analyze the statistical significance of the differences in the estimates of K_s by the two devices. The results showed that the two devices produced varying K_s results for both the soil textures, with the MDI mean values being one order higher than the RS mean. Compared with the permeameter values, the mean values from the RS were closer to the permeameter than the MDI. However, the ANOVA test and the Fisher’s LSD test reported that the variations between the two devices with that of the permeameter were not significant for both the soil textures. On the other hand, the RS and MDI variations were reported significant by the ANOVA and post hoc test.

How to cite: Naik, A. P. and Pekkat, S.: A Comparative assessment of estimated soil hydraulic conductivity from rainfall simulator and infiltrometer using laboratory repacked soil samples, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7099, https://doi.org/10.5194/egusphere-egu21-7099, 2021.

For decades, soil erosion has been a major environmental problem as it degrades the most productive soil layers, which threatens, among other things, food production worldwide. Although these effects have been known for a long time, there are still a variety of challenges to mitigating soil erosion in different ecosystems. As climate change progresses, the risk of soil loss increases, making the preparation of effective solutions very urgent. A current research focus is on the restoration of a protective soil cover following disturbances in the vegetation layer, e.g., through the reestablishment of biological soil crust communities. These are often dominated by bryophytes in humid climates. So far, several studies examined the general protective influence of bryophytes against soil erosion, however only few of them addressed how individual species affect specific erosion processes in detail.

To fill this research gap we investigated the impact of six moss species on soil erosion, percolation and carbon relocation by means of rainfall simulations. Therefore, we used topsoil substrate from four sites in the Schönbuch Nature Park in South Germany which covers different kinds of bedrock and varying soil texture and pH. Subsequently, they were sieved by 6.3 mm and filled into metal infiltration boxes (40 x 30 cm) up to a height of 6.5 cm. The moss species differ in origin (either collected in the field or cultivated in the lab) as well as growth form (pleurocarpous or acrocarpous). Rainfall simulations were performed for bare soil substrates, as well as for moss-covered soil substrates six months later and both in dry and wet conditions. Additionally, we conducted rainfall simulations with leaf and coniferous litter on bare soil substrates. During the simulations we monitored soil moisture in two position - 3 cm depth plus soil surface - with biocrust wetness probes (BWP) and quantified surface runoff, percolation and sediment discharge. Afterwards we determined carbon contents of the sediment and dissolved organic carbon in the liquid phase of runoff and percolated water.

While surface runoff was increased by 5% due to the litter cover compared to the bare soil substrate, sediment discharge decreased to 97%. Runoff rates could also be mitigated by 90 % as a result of the moss cover. Furthermore, due to the dense moss cover sediment rates were almost reduced to zero. Preliminary results show that there are differences between the moss species in terms of sediment discharge, but not in context with runoff. The analyses of carbon contents in surface runoff and the percolated water are still in progress, as is the evaluation of the BWP measurements. These outcomes will be presented at vEGU21.

How to cite: Gall, C., Grabherr, L., Nebel, M., Scholten, T., Thielen, S. M., and Seitz, S.: On the effect of different moss species on soil erosion, percolation and carbon relocation, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8389, https://doi.org/10.5194/egusphere-egu21-8389, 2021.

Carbon dioxide (CO₂) emissions from running waters represent a key component of the global carbon cycle. However, quantifying CO₂ fluxes across air-water boundaries remains challenging due to practical difficulties in the estimation of reach-scale standardized gas exchange velocities (k₆₀₀) and water equilibrium concentrations. Whereas craft-made floating chambers supplied by internal CO₂ sensors represent a promising technique to estimate CO₂ fluxes from rivers, the existing literature lacks of  rigorous  comparisons  among  differently  designed chambers and deployment techniques. Moreover, as of now the uncertainty of k₆₀₀ estimates from chamber data has not been evaluated.  Here, these issues were addressed analyzing the results of a flume experiment carried out in the Summer of 2019 in the Lunzer:::Rinnen - Experimental Facility (Austria). During the experiment, 100 runs were performed  using two different chamber designs (namely, a Standard Chamber and a Flexible Foil chamber with an external floating system and a flexible sealing) and two different deployment modes (drifting and anchored). The runs were performed using various combinations of discharge and channel slope, leading to variable turbulent kinetic energy dissipation rates (1.5 10^-3< ε < 1 10^-1 m² s^-3). Estimates of gas exchange velocities were in line with the existing literature (4 < k₆₀₀ < 32 m d^-1), with a general increase of k₆₀₀ for larger turbulent kinetic energy dissipation rates. The Flexible Foil chamber gave consistent k₆₀₀ patterns in response to changes in the slope and/or the flow rate. Moreover, Acoustic Doppler Velocimeter measurements indicated a limited increase of the turbulence induced by the Flexible Foil chamber on the flow field (22 % increase in ε, leading to a theoretical 5 % increase in k₆₀₀).
The  uncertainty  in  the  estimate  of  gas  exchange  velocities  was  then estimated  using  a  Generalized Likelihood Uncertainty Estimation (GLUE) procedure. Overall, uncertainty in k₆₀₀ was moderate to high, with enhanced uncertainty in high-energy setups. For the anchored mode, the standard deviations of k₆₀₀ were between 1.6 and 8.2 m d^-1, whereas significantly higher values were obtained in drifting mode. Interestingly, for the Standard Chamber the uncertainty was larger (+ 20 %) as compared to the Flexible Foil chamber.  Our study suggests that a Flexible Foil design and the anchored deployment might be useful techniques to enhance the robustness and the accuracy of CO₂ measurements in low-order streams. Furthermore, the study demonstrates the value of analytical and numerical tools in the identification of accurate estimations for gas exchange velocities.
These findings have important implications for improving estimates of greenhouse gas emissions and reaeration rates in running waters.

How to cite: Vingiani, F., Durighetto, N., Klaus, M., Schelker, J., Labasque, T., and Botter, G.: Evaluating stream CO2 outgassing via Drifting and Anchored flux chambers in a controlled flume experiment, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9177, https://doi.org/10.5194/egusphere-egu21-9177, 2021.

The continuous interaction between riparian vegetation and water has important effects on the hydraulics of a river, mainly onto the flood events propagation. Vegetation is a fundamental part of the river ecosystem, but its stage and growth need to be monitored and controlled, especially when the river passes through a densely urbanized area. In fact, vegetation obstructs the streamflow by reducing the hydraulic cross-section area and increasing the roughness of the floodplains and the relative flood risk.

In this study, experiments have been performed at the Fantoli Hydraulic Laboratory at Politecnico di Milano, to validate the methodologies that estimate the hydraulic roughness of vegetated river floodplains, starting from the vegetation properties such as size, density and elastic modulus of a case study. A model based on the mechanical properties of vegetation was used to identify the most suitable material to reproduce the dynamic behaviour of real vegetation on a laboratory scale. The tests were carried out for different spatial configurations of trees, densities and submerged conditions.

The analysis, in addition to relying on experimental work, involves the installation of six piezoresistive pressure sensors located both in the floodplains and in the main channel, to monitor head losses in a representative reach of the river under study. The field measurements allow validation of the approach used in laboratory tests.

How to cite: Herrera Gomez, L. V., Ravazzani, G., Ferri, M., and Mancini, M.: Hydraulic roughness estimation in vegetated floodplains, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14426, https://doi.org/10.5194/egusphere-egu21-14426, 2021.

The water storage in soil is a dynamic process that changes with soil, vegetation and climate properties. Water retention curves, that describe the relationship between the soil water content (θ) and the soil water potential (ψ), are used to model soil water flow and root water uptake by the plants. The overall objective of this study is to derive the retention curves of soils at two forested (Agia Marina, Platania) and two irrigated (Galata, Strakka) sites in Cyprus from in-situ soil moisture and soil water potential observations. 
The long-term (1980 – 2010) average annual rainfall at Strakka olive grove (255 m elevation), Agia Marina P. brutia forest (640 m), Galata peach orchard (784 m) and Platania P. brutia forest (1160 m) is 298, 425, 502 and 839 mm, respectively.  The average soil depth at Agia Marina is 14 cm, while at other sites it is around 1 m. We installed a total of 18 TEROS21 soil water potential sensors, 37 5TM and 19 SMT100 soil moisture sensors, at different soil depths at the four sites. 
Results from January 2019 to January 2021 show differences in the water retention curves of the four sites due to different soil textures. At the forested sites, θ reached wilting point at the summer period, indicating that trees extend their roots beyond the soil profile, to the bedrock in order to survive. At the irrigated sites, θ exceeds field capacity during irrigation, indicating over-irrigation. We found different water retention relations after rainfall and after irrigation, indicating that irrigation has an uneven spatial distribution. These findings suggest that the irrigation in these fields is not optimal and farmers may need to increase the number of irrigation drippers, while reducing the irrigation amount per dripper. From a monitoring perspective, increasing the number of sensors may give a better representation of the soil moisture conditions. 
The research has received financial support from the ERANETMED3 program, as part of the ISOMED project (Environmental Isotope Techniques for Water Flow Accounting), funded through the Cyprus Research and Innovation Foundation.

How to cite: Eliades, M., Bruggeman, A., Djuma, H., Siakou, M., Venetsanou, P., Zoumides, C., and Huebner, C.: Soil water dynamics in forested and irrigated sites in Cyprus , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14170, https://doi.org/10.5194/egusphere-egu21-14170, 2021.

Headwater streams are important for their hydrological function and for their significant contribution to the riverine ecosystems. Nevertheless their study has always been challenging because of the ephemeral and intermittent nature of those streams. Maps representing the active part of the river network are usually drawn after field surveys performed under different hydrologic conditions, which enable an objective evaluation of the temporal changes in the length of the active network. This method is useful to describe seasonal variations of the stream length, but has significant limitations when it comes to the description of event-based changes of the flowing network, provided that visual inspections of entire catchments are highly time-consuming. In this work, electrical resistance (ER) sensors were used to analyze event-based active network dynamics along some of the tributaries of an Alpine creek in northern Italy. Current intensity values were collected every 5 minutes by the sensors and a threshold electrical signal was identified to distinguish between wet and dry status of the reaches where the probes were placed. A statistical analysis revealed a good correlation among the mean current intensity recorded, the exceedance probability of the threshold and the persistency of the nodes. Data collected by the sensors were also interpolated in space along the network to obtain a sequence of maps of the active and dry parts of the stream network. From each map the wet length (L) of the watercourse was derived and linked to the corresponding discharge (Q) at the outlet of the catchment. Small and intense precipitation events had different effects on the variations of Q and L: the network length was found to be more sensitive than discharge to small precipitation inputs; relevant stream flow variations were instead observed only during significant events that originated the largest changes in the active network length.  This heterogeneous behaviour negatively affected the quality of the fitting of empirical discharges vs. wet length data through a power law model. Water presence sensors provide an opportunity to study in depth the spatiotemporal dynamics of the active length of intermittent streams and link such dynamics to the relevant hydrological drivers.

How to cite: Zanetti, F., Durighetto, N., Vingiani, F., and Botter, G.: Analysis of the active length dynamics on intermittent streams using water presence sensors, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8526, https://doi.org/10.5194/egusphere-egu21-8526, 2021.

To improve knowledge of hydrological and hydrogeological flow processes and their dependency on climate conditions it is becoming increasingly important to integrate sensors technology, independent observation methods, and new modeling techniques. Established isotope methods are usually regarded as a supplement and extension to classical hydrological investigation methods but are rarely included in soil water balance models. However, the combination could close knowledge gaps and thus lead to more precise and realistic predictions and therefore to better water management. Within the Wasserpfad project, a project of the Department of Civil Engineering at the TH Lübeck, soil moisture has been measured since May 2018. SMT100 soil moisture sensors from TRUEBNER GmbH are used at depths of 20, 40, 60, and 80 cm. Next to the station a 2m deep soil profile was taken in 2020, to estimate groundwater recharge using stable isotope equilibration methods and cryogenic extraction combined with soil water balance modeling. Vertical profiles of stable isotopes have been determined with a 10-cm resolution and measured with Tunable Diode Laser spectrometry. Percolation through the soil profile has been estimated based on the convolution of a seasonal input function using advection-dispersion transport models. Percolation rate estimate based on environmental isotope profiles results in 230 mm per year. Fitting of the advection-dispersion equation using a sinusoidal isotope input fitted to available time series provides an estimate of 255 mm per year. This difference is due to the dispersion effect on the isotope minima and maxima. The result of modeling the soil moisture data with a soil water balance model integrating the Richards equation for water transport and Penmen-Monteith based calculation of actual evaporation is used to verify the percolation rates. The analysis of soil moisture and isotope data by modeling provides a direct and efficient way to estimate the percolation rate. The combination of isotope methods with classical hydrological measuring techniques offers the possibility to verify results, to calibrate models, or to investigate the limits of isotope methods. Thus, flow processes can be predicted more reliably in the future.

How to cite: Krüger, N., Külls, C., and Kock, M.: Groundwater recharge estimates combining soil isotope profiles and classical soil water monitoring techniques, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9061, https://doi.org/10.5194/egusphere-egu21-9061, 2021.

Soil water content (SWC) dynamics can strongly influence catchment runoff generation processes. Knowledge about the amount and spatiotemporal distribution of SWC at the catchment scale can be useful for constraining and evaluating rainfall-runoff models.  While it is still challenging to obtain catchment scale-representative measurements of SWC, recent advances in cosmic ray neutron sensor (CRNS) technology have provided opportunities to obtain hectare scale data on SWC. Here we present a new method for obtaining spatially variable near-surface SWC by combining a high temporal resolution static CRNS sensor with ‘snapshot’ surveys using a portable CRNS. We also explored the role of these soil water storage data for catchment in rainfall-runoff generation models. We used ~4-years of near-surface SWC data from a static CRNS located in a humid mixed-agricultural catchment (~10km²) in Scotland. These data were complemented with at least three ‘snapshot’ portable CRNS surveys in each of the four main soil-land use (SLU) units in the catchment to produce SWC timeseries for each of these units. Two SLU units involved rotational crops under poorly or imperfectly draining mineral soils; one SLU unit typically supports livestock farming on freely draining mineral soils and the fourth, moorland on organic-rich soils.  While the moorland SLU unit on organic soils had the greatest difference in SWC dynamics under the static CRNS and other SLUs, we also found subtle SWC differences between mineral soil SLU units under different agricultural management. We then evaluated the additional information generated by the combined CRNS method in a rainfall-runoff model (HBV-light) calibration of dynamic catchment storage. For the purpose, we used areal weighted SLU SWC timeseries and compared the model calibration to that using the static CRNS alone. In this case, differences were marginal and model efficiencies similar, suggesting that static CRNS data from a landscape-representative location may be sufficient to inform rainfall-runoff model calibration at the catchment scale.  However, this may depend on model structure and the degree to which SWC dynamics vary within the landscape. This study demonstrated the potential of expanding the information value of permanently installed CRNS sensors using portable CRNS surveys in the context of humid mixed-agricultural environment, although testing in different environments would be required to evaluate wider applicability.

How to cite: Dimitrova Petrova, K., Rosolem, R., Soulsby, C., Wilkinson, M., Lilly, A., and Geris, J.: Combining static and portable Cosmic Ray Neutron Sensor (CRNS) data to assess catchment scale heterogeneity in soil water content and implications for runoff generation, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4751, https://doi.org/10.5194/egusphere-egu21-4751, 2021.

Monitoring and profiling the isotopic composition of soil water in combination with groundwater isotope hydrology are commonly used in studying flow and transport in soils as well as in estimating groundwater recharge. Establishing the isotopic composition of local precipitation is of essence. Towards this end and in facilitating the application of isotope hydrology in Troodos Fractured Aquifer (TFA), precipitation was monitored in 16 precipitation sampling stations, stretching from the shoreline up to 1725 m above m.s.l., from January of 2015 to December of 2017. A seasonal trend was discerned, with isotopically depleted rainfall occurring in December as opposed to the more enriched autumn and spring rainfall. Northern European air masses appear to prevail during the months of December to January during which d values tend to be on average above 25‰ whereas the more enriched rain with the lowest d values occurs in July. The averaged seasonal effect between 2015 and 2017 on δ18O, δ2H and d values are 4.53‰, 30.98‰ and 14.93‰, respectively. Cyprus’ Local Meteoric Water Line (LMWL) was found to be equal to δ2H = (6.58±0.13)*δ18O + (12.64±0.91) and a general decrease of 1.22‰ for δ2H and 0.20‰ for δ18O in precipitation was calculated per 100 m altitude.  Similar values have been found by other researchers for the region. These variations in the isotope composition of rainfall can be used to earmark seasonal input of recharge water and for deriving percolation rates from tracing their movement in the soil column.

How to cite: Christofi, C., Bruggeman, A., and Kuells, C.: The Isotopic Composition of Cyprus Precipitation. A Tool of Isotope Hydrology., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9210, https://doi.org/10.5194/egusphere-egu21-9210, 2021.

Groundwater dynamics play a crucial role in the spreading of a soil and groundwater contamination. However, there is still a big gap in the understanding of the groundwater flow dynamics. Heterogeneities and dynamics are often underestimated and therefore not taken into account. They are of crucial input for successful management and remediation measures. The bulk of the mass of mass often is transported through only a small layer or section within the aquifer and is in cases of seepage into surface water very dependent to rainfall and occurring tidal effects.

This study contains the use of novel real-time iFLUX sensors to map the groundwater flow dynamics over time. The sensors provide real-time data on groundwater flow rate and flow direction. The sensor probes consist of multiple bidirectional flow sensors that are superimposed. The probes can be installed directly in the subsoil, riverbed or monitoring well. The measurement setup is unique as it can perform measurements every second, ideal to map rapid changing flow conditions. The measurement range is between 0,5 and 500 cm per day.

We will present the measurement principles and technical aspects of the sensor, together with two case studies.

The first case study comprises the installation of iFLUX sensors in 4 different monitoring wells in a chlorinated solvent plume to map on the one hand the flow patterns in the plume, and on the other hand the flow dynamics that are influenced by the nearby popular trees. The foreseen remediation concept here is phytoremediation. The sensors were installed for a period of in total 4 weeks. Measurement frequency was 5 minutes. The flow profiles and time series will be presented together with the determined mass fluxes.

A second case study was performed on behalf of the remediation of a canal riverbed. Due to industrial production of tar and carbon black in the past, the soil and groundwater next to the small canal ‘De Lieve’ in Ghent, Belgium, got contaminated with aliphatic and (poly)aromatic hydrocarbons. The groundwater contaminants migrate to the canal, impact the surface water quality and cause an ecological risk. The seepage flow and mass fluxes of contaminants into the surface water were measured with the novel iFLUX streambed sensors, installed directly in the river sediment. A site conceptual model was drawn and dimensioned based on the sensor data. The remediation concept to tackle the inflowing pollution: a hydraulic conductive reactive mat on the riverbed that makes use of the natural draining function of the waterbody, the adsorption capacity of a natural or secondary adsorbent and a future habitat for micro-organisms that biodegrade contaminants. The reactive mats were successfully installed and based on the mass flux calculations a lifespan of at least 10 years is expected for the adsorption material.  

How to cite: Verreydt, G., Van Putte, N., De Kleyn, T., Cool, J., and Maiheu, B.: Innovative real-time sensing of flow dynamics in groundwater and sediments to map contaminant spreading, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13338, https://doi.org/10.5194/egusphere-egu21-13338, 2021.

Drainage below the root zone of irrigated crops and trees is often an unknown component of the water balance. This drainage water could recharge underlying aquifers and flow to streams and is not part of water consumed by crops, as used in water productivity computations. Drainage from fields with irrigation systems that wet only part of the soil is difficult to estimate. The objective of the research was to develop a water balance model with a dynamic wetted area for analyzing soil water balance components from daily soil moisture observations. The method was applied in an olive orchard in Cyprus, with approximately 35% canopy cover. Soil moisture sensors (SMT100, Truebner and 5TM, Decagon) were installed at six trees, at 10-, 20-, 40- and 60-cm depth, approximately 90 cm from the trunk of the tree. Soil moisture was recorded hourly. The trees were irrigated weekly, with a single spaghetti tube with a discharge rate of approximately 135 L/hr. Daily reference evapotranspiration was computed with the Penman-Monteith equation from meteorological observations recorded inside the orchard (WS500, Lufft). Rainfall was measured with a tipping bucket rain gauge (15189, Lambrecht).

The model computes a daily volumetric water balance for the canopy area of the tree. During the irrigation season, soil moisture observations were assumed to represent the soil volume wetted by irrigation. Drainage below the 70-cm root zone occurred when soil moisture exceeded the field capacity, as derived from hourly observations. A canopy-area crop coefficient (Kcc-max) was estimated for all irrigation days without drainage by minimizing the sum of the daily evapotranspiration in excess of the maximum evapotranspiration (Kcc-max ETo). This one-sided error was controlled by maintaining a positive difference between Kcc-max and Kcc the day after irrigation. Wetted areas were subsequently computed for all irrigation days without drainage. For irrigation days with soil moisture above field capacity, the wetted area was adjusted manually, such that drainage was smaller on the second day than on the irrigation day, using a Kcc-max for both days. During the May to November 2019 irrigation season, drainage was 8 mm over the field area, for a field capacity of 36%, a Kcc-max of 1.3, and an error of 16 mm. Assuming a field capacity of 38%, drainage was 3 mm over the field area, with a Kcc-max of 1.4, and an error of 17 mm. Overall, the model provided a quick and robust way of estimating the irrigation water balance components.

This research has received financial support from the ERANETMED3 program, as part of the ISOMED project (Environmental Isotope Techniques for Water Flow Accounting), funded through the Cyprus Research and Innovation Foundation.

How to cite: Bruggeman, A., Siakou, M., Eliades, M., Djuma, H., and Zoumides, C.: A daily water balance model with a dynamic wetted area for estimating drainage from soil moisture observations in an irrigated orchard, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14566, https://doi.org/10.5194/egusphere-egu21-14566, 2021.

Since the middle of the 20th century, urban-tourist development in tourist destinations on the Mediterranean coast has required the creation of complex water supply systems to guarantee a growing water demand. At present, the challenges posed by climate change around the management of water resources requires the implementation of adequate water policies and sustainable environmental solutions to foster the adaptation to a foreseeable future characterized by lower availability of conventional water resources and more recurrent and intense droughts. In this context, the link between the scientific field, the stakeholders from the tourism sector, and the decision-makers is vital to favor viable, effective, and consensual solutions that shift the focus from the objective of guarantee tourist water demand to a sustainability scenario from both an environmental, economic, and social point of view. Therefore, it is relevant to question whether there is a large gap between the actions and focus of attention in each of these three areas (scientific, decision-makers, and stakeholders). In other words, does scientific research related to water consumption by the tourism sector adequately respond to the knowledge needs required by stakeholders and decision-makers to achieve the aforementioned sustainability objectives? Through a literature review, this study addresses the main topics, methodologies, and results related to water consumption in hotels on the Spanish Mediterranean coast and their possible impact on the actions made by managers, decision-makers or stakeholders from the tourism sector. To evaluate the science-policy interface, it has also been made a policy review of the main laws, regulations, and plans developed by the different levels of public administration and other private entities in the tourism sector concerning water consumption in hotels, for the Benidorm case study, located in the southeast of Spain. To identify the measures implemented by stakeholders from the tourism sector to reduce water consumption and their vision about the challenges and barriers in this issue, we have taken into account the results of previous projects in which more than twenty surveys and interviews have been carried out to the hotel managers as well as to the Benidorm hotel association (HOSBEC). Likewise, to contextualize the results of these surveys and interviews, we have analyzed the raw water supply data provided by the entity in charge of this service, the Marina Baja Water Consortium, as well as billing and smart meter data from the hotels, provided by the company in charge of the local water supply service, Hidraqua. The results will make possible to highlight the links and differences found between the problems and research approaches raised from the scientific field, the regulations and plans proposed by the public administration and other private decision-makers and the actions and future challenges identified by the tourism sector in the city of Benidorm. The identification of the existing gaps between the three areas (scientists, policy-makers, and stakeholders) will be useful to reshape the agenda of future research and re-think the role of science when responding to managers and decision-makers’ requests on water management and tourism nexus.

How to cite: Villar-Navascués, R. A., Ricart, S., Rico-Amorós, A. M., and Hernández-Hernández, M.: Is scientific research on water-tourism nexus responding to the challenges identified by stakeholders and policy-makers? The case of Benidorm, Spain, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-11041, https://doi.org/10.5194/egusphere-egu21-11041, 2021.

Hydro-Meteorological Hazards (HMH) such as drought, floods and storm surge have always constituted a threat to social-ecological systems (SES) but, due to increasing uncertainties caused by climate and by rapidly changing socio-economic boundary conditions, it is necessary to step up effort to mitigate the risks. More attention should be devoted to understanding and managing the transition from traditional management regimes to more sustainable and resilient regimes that take into account environmental, technological, economic, institutional and cultural characteristics of river basins.

Since the 1990s many scholars, from both natural and social sciences, have urged to integrate knowledge and shed light on the functioning of the SESs in order to increase resilience to perturbances (Berkes and Folke 1998). As sustainability science is mainly a problem-driven and solution-oriented field that follows a transformational agenda (Lang 2012), it becomes evident that the nexus between environmental, political and institutional dimensions cannot be ignored to accelerate the path toward sustainability.  

There is consensus that the complex, non-linear and rather unpredictable nature of HMHs, exacerbated by climate change, should require a more adaptive (Armitage 2007), flexible and holistic (Holling 2002) management approach that can speed up and reinforce the learning loops to allow for more rapid assessment and implementation of the consequences of new insights and scientific evidence (Pahl Wostle 2007). Cooperation among a wide range of stakeholders with different knowledge, expertise and views is often indicated as a prerequisite to establish a resilient and adaptive water management regime (Olsson et al. 2004). These principles mainstreamed since the beginning of the 2000s and synthesized by concepts like “co-management”, “adaptive and integrated management”, or “adaptive co-management”, are the pillars of what is considered a paradigm shift in water management (Pahl Wostle and Nicola 2011) and have inspired institutional settings, policies, and practices.

However, the debate is still ongoing to determine at what stage of the transition we are in, whether the aforementioned principles have been adopted and translated into practices on a wide scale, and whether and how such practices have contributed to increasing the resilience of the SES. It will be critically examined the literature trying to identify the main trend of the last two decades. The review will be accompanied by the case-studies upon which theories have been built and tested.

How to cite: Mannocchi, M.: The transition toward resilient water management regimes: where are we now?, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13592, https://doi.org/10.5194/egusphere-egu21-13592, 2021.

Balancing socio-ecological systems among competing water demands is a difficult and complex task. Traditional approaches based on limited, linear growth optimization strategies overseen by command/control have partially failed to account for the inherent unpredictability and irreducible uncertainty affecting most water systems due to climate change. Governments and managers are increasingly faced with understanding driving-factors of major change processes affecting multifunctional systems. In the last decades, the shift to address the integrated management of water resources from a technocratic ‘‘top-down’’ to a more integrated ‘‘bottom-up’’ and participatory approach was motivated by the awareness that water challenges require integrated solutions and a socially legitimate planning process. Assuming water flows as physical, social, political, and symbolic matters, it is necessary to entwining these domains in specific configurations, in which key stakeholders and decision-makers could directly interact through social-learning. The literature on integrated water resources management highlights two important factors to achieve this goal: to deepen stakeholders’ perception and to ensure their participation as a mechanism of co-production of knowledge. Stakeholder Analysis and Governance Modelling approaches are providing useful knowledge about how to integrate social-learning in water management, making the invisible, visible. The first one aims to identify and categorize stakeholders according to competing water demands, while the second one determines interactions, synergies, overlapping discourses, expectations, and influences between stakeholders, including power-relationships. The HydroSocial Cycle (HSC) analysis combines both approaches as a framework to reinforce integrated water management by focusing on stakeholder analysis and collaborative governance. This method considers that water and society are (re)making each other so the nature and competing objectives of stakeholders involved in complex water systems may affect its sustainability and management. Using data collected from a qualitative questionnaire and applying descriptive statistics and matrices, the HSC deepens on interests, expectations, and power-influence relationships between stakeholders by addressing six main issues affecting decision-making processes: relevance, representativeness, recognition, performance, knowledge, and collaboration. The aim of this contribution is to outline this method from both theory and practice perspective by highlighting the benefits of including social sciences approaches in transdisciplinary research collaborations when testing water management strategies affecting competing and dynamic water systems.

How to cite: Ricart, S. and Castelletti, A.: The HydroSocial Cycle approach to deepen on socio-ecological systems analysis and water management, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-599, https://doi.org/10.5194/egusphere-egu21-599, 2021.

Stakeholder Participation is recognized in both flood risk governance research and praxis. It is argued to emphasize empowerment, equity, learning and trust among actors. Projects that fail to adequately understand stakeholder dynamics turn to have undesired results. We take a normative and instrumental approach to stakeholder analysis by categorizing and investigating stakeholder relationships. With the wide array of roles that different stakeholders play, it is important to adopt holistic approaches in engaging them. Our approach is three-tiered, aimed at integrating and enhancing stakeholder participation and involvement.

We present research on stakeholder identification, categorization and mapping within the ongoing PARADeS project on participatory assessment of flood-related disaster prevention in Ghana. We define stakeholders to include all formal governance institutions, NGOs, Public and Private Research Institutions as well as civil society and their organizations. As the general motivation of the project constitutes a combination of research, development, and institutional strengthening activities, the objective is to engage with the relevant stakeholders of flood-related disaster management in Ghana, collaboratively identify weaknesses in the flood risk management system and starting points for improving these systems. We thus, 1) undertook a network-based stakeholder analysis, and 2) developed a strategy for stakeholder integration and participation within the PARADeS project.

We elaborate a three-tiered aim of participation concept to be used within our Project where subsets of identified stakeholders serve different purposes: 1) To provide and coordinate access to other stakeholders for project work packages/partners, 2) To analyze stakeholder networks and their role for FRM in Ghana, and 3) To create co-ownership between project collaborators and target capacity building and multiplier effects to ensure long-lasting project output implementation and transfer of responsibility from the project to respective institutions in Ghana. First, we developed a matrix that helped us to identify and preliminarily categorize all stakeholders from a variety of sources following a multi-level governance approach. The categorization included but not limited to sectors of operation, political level, main functions of the stakeholders, and whether they were state/non-state or otherwise identified, their corresponding contact persons and different approaches in contacting them. Based on this, we performed a stakeholder mapping exercise which forms a basis for a Social Network Analysis to be done at a later time. The mapping exercise offers a vivid visualization of the stakeholders identified, their affiliations, sector and political level of operation, and is discussed and revalidated collaboratively with practitioners and policy actors.

In the further course of the project, the three-tiered approach to participation builds grounds for collaboration not only amongst scientists/researchers across disciplines but also among practitioners in the field of flood-related disaster risk management.

How to cite: Ziga-Abortta, F. R., Kruse, S., Höllermann, B., and Ntajal, J.: Stakeholder Participation in Flood-Related Disaster Risk Management in Ghana, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10819, https://doi.org/10.5194/egusphere-egu21-10819, 2021.

Introduction

The Horizon 2020 project FANFAR (www.fanfar.eu) aims to develop a Flood Early Warning Systems (FEWS) for West Africa. Prospective end-users of the FANFAR system include the hydrological services and emergency services of 17 countries in West Africa. Close involvement of end-users during the development phase can enhance effectiveness and usefulness of early warning systems (Reid, 2006). Therefore, FANFAR took a co-development approach between the consortium of developers and the end-users (Andersson, Ali, et al., 2020). Important vehicle for co-development are three workshops, organised over three years by the development consortium. Workshops were attended by one representative from hydrological services and one from emergency services from each country. The objectives of co-development included: tailoring to user- and context specific preferences and requirements, acquiring technical feedback on system components, enhancing user skills and capacity, building trust and ownership, enabling performance testing and enhancing system uptake.

Approach

Several strategies and interventions have been deployed to meet the objectives. Firstly, a Multi-Criteria Decision Analysis was conducted to establish the end-users’ primary objectives and system configurations to best meet these (Lienert, Andersson, & Silva Pinto, 2020). Furthermore, including the execution of regular surveys to explore user experiences with the system and receive technical feedback. Two different pen-and-paper surveys were taken during the both the second and third workshop sessions: (1) a survey exploring long-term and detailed information on usage, performance, preferences, obstacles and experience of using FANFAR and (2) a survey eliciting detailed technical feedback on separate system components. A third, shorter survey was conducted online on a monthly basis during the rainy season (May-October 2020) focussing on day-to-day operational usage and performance. Here, we summarise some main insights from these three types of surveys.

Outcomes

The data on user experience with the FANFAR system gathered during these interventions enabled the development team to improve the forecast system. For example, accuracy was identified as critical issue to improve. In response, the development team initiated several activities aimed at improving accuracy, including model calibration, catchment re-delineation, assimilation of local streamflow observations and EO data, and utilising alternative meteorological data (Andersson, Santos, et al., 2020).

There was an important discrepancy between the reported overwhelming intention to use FANFAR (82-93%) and the actual usage (28-46%). One reason could be related to the reported barrier posed by the initial state of the system, and the lack of accuracy mentioned above. Furthermore, priorities and resources might partly explain these numbers. However, these finding could be skewed by the changing composition of respondents between surveys, compromising their representativeness. Indeed, the user statistics of the online platform show a rise in visits. Finally, users seem to prioritise a functional system delivering daily predictions over a complex system with broad functionality.

Overall, our co-development has been a positive one. Participation has been strong and continuous, with an increasing number of organisations and their representatives partaking in workshops. In addition, participation outside the workshops (during the rainy season) was encouraging, particularly in the light of its voluntary nature.

References
Andersson, J., Ali, A., Arheimer, B., Crochemore, L., Gbobaniyi, B., Gustafsson, D., . . . Machefer, M. (2020). Flood forecasting and alerts in West Africa-experiences from co-developing a pre-operational system at regional scale. Paper presented at the EGU General Assembly Conference Abstracts.
Andersson, J., Santos, L., Isberg, K., Gustafsson, D., Musuuza, J., Minoungou, B., & Crochemore, L. (2020). Deliverable: D3.2 Report documenting and explaining the hydrological models. Retrieved from available at: https://fanfar.eu/resources/:
Lienert, J., Andersson, J., & Silva Pinto, F. (2020). Co-designing a flood forecasting and alert system in West Africa with decision-making methods: the transdisciplinary project FANFAR. Paper presented at the EGU General Assembly Conference Abstracts.
Reid, B. (2006). Global early warning systems for natural hazards: systematic and people-centred. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 364(1845), 2167-2182. doi:doi:10.1098/rsta.2006.1819

How to cite: Kuller, M., Andersson, J., and Lienert, J.: Systematic User Feedback to Co-develop a Flood Early Warning System in West Africa, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3136, https://doi.org/10.5194/egusphere-egu21-3136, 2021.

This research, conducted within the H2O-T2S project, is located in peri-urban areas of three cities in India: Pune, Hyderabad, Kolkata. Peri-urban areas are where the rural to urban transition is most visible. A key challenge for peri-urban areas is sustainable management of water resources. Peri-urban water resources in India are under threat from growing water demand and ineffective institutions. Interdisciplinary research of existing water-based livelihoods, household water use, and peri-urban institutions in these three regions shows that current urban transformations are unsustainable. Given the dynamic nature of peri-urban contexts, short and long-term vulnerabilities must be considered. An adaptation policy pathways approach can help peri-urban actors develop longer-term transformative plans. This study describes the design and execution of a participatory process to design context-specific pathways with peri-urban communities and governments in India.

This presentation outlines the key steps in our customized pathways approach for the peri-urban context. Due to the covid-19 pandemic, initial plans to implement these steps through a series of stakeholder workshops were replaced by remote pathways design using the Delphi method. We present a step-by-step methodology to engage peri-urban actors in the design of longer-term adaptive plans for water resources in the future. Results are presented for Hadia village (Kolkata), one of the three peri-urban case studies. It reveals the range of future normative scenarios developed for this village and a pathways schematic towards these scenarios.

Our results demonstrate the value of engaging local actors in the design of adaptive plans for peri-urban water resources. This study offers insights for ways to conduct transdisciplinary research even when face to face interactions are not feasible.

How to cite: Gomes, S. L., Luft, S., Chakraborty, S., Hermans, L. M., and Butsch, C.: Transdisciplinary Design of Adaptation Pathways in Peri-urban India: Planning for Water Needs in a Sustainable Urban Transition , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13276, https://doi.org/10.5194/egusphere-egu21-13276, 2021.

The question ‘how scale matters’ from experienced policy makers in adaptive water management motivated us to explore the issue. In search for climate resilience of brook catchments stakeholders collaborate. Those collaborations involve dynamic proximity, giving rise to innovative, creative solutions using natural hydrological and landscape processes. Dynamic proximity is known from innovation research in the field of high-tech regional economic development. The question is whether dynamic proximity among stakeholders influences success of joint knowledge production (JKP) processes as well. We focus on a more nature-tech context of regional economic development: creating nature-based solutions (NbS) to support climate resilience. The conceptual model to study the creative process of JKP combines the four dimensions of JKP with four forms of dynamic proximity. Along this matrix quotes of stakeholders were analysed from seven semi-structured interviews. At least one stakeholder in the process for the brook-restoration of the Aa (the Netherlands) was selected from industry, academia, government and non-profit organizations (following the ‘quadruple helix model’). Findings show that stakeholders who are versatile in using various forms of social, cognitive, institutional and geographical dynamic proximity in the process of JKP experience the process as more successful. Moreover, stakeholders overdoing the institutional or geographical aspects of proximity run into adverse effects, a mechanism recognized in economic geography as the proximity paradox. Furthermore, stakeholders are better supported when they use knowledge instruments, but only when keeping in mind the balance of forms of dynamic proximity. Findings were validated against two stakeholders’ experiences in another process for the Aa of Weerijs (the Netherlands). We suggest refining the model by adding two forms of dynamic proximity relating to interests and to resources, enabling a sharper focus on knowledge production under the heading of cognitive proximity. So, scale matters in such rural, natural processes. The perspective on proximity helps innovation, if proximity among stakeholders does not become too proximate. We have summarised findings in the form of a proximity tool, which is useful for optimizing the science-policy interface in regional adaptive water management.

How to cite: Brok, E., Floor, J., van Lamoen, F., and Lansu, A.: How scale matters in joint knowledge production for nature-based solutions. Dynamic proximity among stakeholders in climate adaptive water management for brook catchment Aa, the Netherlands, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8514, https://doi.org/10.5194/egusphere-egu21-8514, 2021.

Water is very important for human consumption, production and services and also for inspiration, recreation, landscapes, ecosystems and wild life. UN and EU policies highlights the interaction of historical scientific, economic, societal and environmental factors and the linkage of water policies with biodiversity protection and Climate Change adaptation.  According to the European Green Deal (2019), for a fair and prosperous society, with a modern, resource-efficient and competitive economy working across sectors and disciplines, will be needed, also involving local communities. Moreover Political and management processes may take benefits from specific participatory Tools.

The Emilia-Romagna Regional Agency for Prevention, Environment and Energy (Arpae) helps sustainability developing  actions for water protection, water use, flood management and education to sustainability.  

Arpae Hydrological Service (HS) supports flood management and water management, as also design and management of hydraulic structures, through the Flood Early Warning System FEWS and  the Drought Early Warning System DEWS. Arpae HS also collect and publish hydrological time series (water, solid transport) and stage-discharge equations.

Within FP7 Enhance (2017) multi risk analysis and Public Private Partnership (PPPs) experiences were supported by  modeling tools combining flood /earthquake/Climate Change scenarios in a densely populated, highly developed land reclamation territory. An Application of the System for Economic and Environmental Accounting for Water (UN SEEA -Water) was developed in 2017. Within Interreg Proline-CE (2019), the FEWS and DEWS Systems, respectively supporting the Flood Forecasting Center and the Observatory on Water Uses, were proposed as Best Management Practices (BMPs) for land and water management useful for drinking water protection. BMPs where tested through workshops, questionnaires,  meetings and technical visits, useful for dissemination and  stakeholders involvement. H2020 Clara was useful to experience co-design/co-development approaches, to explore market segments and business models for water knowledge and climate services, and to set dedicated Policy Briefs for Water and Climate Change Adaptation; Arpae HS developed a set of modeling services  (Clara PWA) related to water management, solid transport, water quality and habitat availability, useful to understand the  influenced of climate change and the needs and proposal coming from market and  the institutions. Interreg boDEREC-CE is a current project on pharmaceutical and personal care pollutants (PPCPs), aimed at developing tools and strategies for protection of drinking water, water ecosystems and public health from pollution, bacterial resistance, toxicity and pathogens.

Arpae HS through these experiences has gained awareness of the inter linkage of hydrology with other sectors (economy, Earth sciences, ICT, health, ecology, society) and of the importance of developing specific decision support tools maximizing stakeholder participation, societal dissemination, transparency, education to sustainability and experts involvement.

How to cite: Ricciardi, G., Allodi, A., Bordini, F., Branchi, M., Cogliandro, F., Comune, E., dell'Aquila, V., Del Longo, M., Nicolosi, G., Noberini, M., Pizzera, F., Tonelli, F., and Tugnoli, F.: Hydrology across disciplines: the experience of a Public Hydrological Service in Italy, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7288, https://doi.org/10.5194/egusphere-egu21-7288, 2021.

Spring floods have generated colossal damages to residential areas in the Province of Quebec, Canada, in 2017 and 2019. Government authorities need accurate modelling of the impact of theoretical floods in order to prioritize pre-disaster mitigation projects to reduce vulnerability. They also need accurate modelling of forecasted floods in order to direct emergency responses. 

We present a governmental-academic collaboration that aims at modelling flood impact for both theoretical and forecasted flooding events over all populated river reaches of meridional Quebec. The project, funded by the ministère de la Sécurité publique du Québec (Quebec ministry in charge of public security), consists in developing a diagnostic tool and methods to assess the risk and impacts of flooding. Tools under development are intended to be used primarily by policy makers. 

The project relies on water level data based on the hydrological regimes of nearly 25,000 km of rivers, on high-precision digital terrain models, and on a detailed database of building footprints and characterizations. It also relies on 24h and 48h forecasts of maximum flow for the subject rivers. The developed tools integrate large data sets and heterogeneous data sources and produce insightful metrics on the physical extent and costs of floods and on their impact on the population. The software also provides precise information about each building affected by rising water, including an estimated cost of the damages and impact on inhabitants.  

How to cite: Parent, A.-C., Fournier, F., Anctil, F., Morse, B., Baril-Boyer, J.-P., and Marceau, P.: Development of interactive diagnostic tools and metrics for the socio-economic consequences of floods, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8060, https://doi.org/10.5194/egusphere-egu21-8060, 2021.

Building the tools to speed up the policy design cycle: letting policy makers work with hydrologic models themselves through eWaterCycle

Hydrologists are important experts that policy makers rely on when making water related decisions. Through policy briefs, often including scenario simulations, policy makers are informed about the consequences their (intended) policies (or lack thereof) will have.

In drafting policy briefs, or choosing which scenario to run, scientists inevitably make political decisions, from obvious ones (how to weigh the importance of one land use type over another) to more hidden ones (using Kling-Gupta efficiency, which focuses more on low flow, to calibrate a model instead of Nash-sutcliffe efficiency, which focuses more on high flows). Ideally one wants to design the policymaker - scientist interaction such that most political decisions are made by the policymaker, without requiring her/him to become an expert hydrologist in the process. Any remaining (inevitable) decisions made by the hydrologist should be as transparent as possible.

The eWaterCyle hydrologic research platform facilitates this type of policy maker - hydrologists interaction. Within the platform experiments such as scenario runs are Jupyter notebooks that a governmental data-scientist can construct without having to be an expert in the hydrological models used: these are stored in (OPEN and FAIR) containers. Interactive web applications  can be easily built on top of these notebooks using widgets, to allow the ultimate political decision maker to explore a broader range of policy options, instead of having to choose from a view of pre-run scenarios. 

We will present a few examples of how the eWaterCycle hydrological research platform can be used to support water-relevant policy decision making.

How to cite: van de Giesen, N., Hut, R., and Drost, N. and the Netherlands eScience Centre: Building the tools to speed up the policy design cycle: letting policy makers work with hydrologic models themselves through eWaterCycle, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10056, https://doi.org/10.5194/egusphere-egu21-10056, 2021.

This work carries the social learning process out via Living Labs in order to construct a common vision on sustainable groundwater management. In this process, the scientific and local knowledge are integrated. This study is part of Sustain-COAST project co-funded by PRIMA programme. Stakeholders’ active engagement is realized via Living Labs, which are participatory actions that encourage the dialogue among private and public actors, create institutionalized space for discussion and vision sharing, and analyze the stakeholder-suggested mitigation options.

A stakeholder mapping took place, that is  the list of all the key groups, organizations, and people involved to water management in the study area. Further analysis was carried out to better understand stakeholders’ roles and perspectives, within the first Living Lab, organized in Malia. 55 stakeholders interacted gathered, including water users, policy makers, local and regional authorities, water management and supply associations, socio-ecological and cultural associations, NGOs, citizens, technicians, external experts, scientists.

Stakeholders got involved in social learning actions, knowing each other, expressed their motivations and expectations to participate in the first Living Lab and the project. Afterwards, a participatory session followed by implementing digital ICT tools (Mentimeter App.), which is an opinion survey technique that might improve societal awareness and stakeholders’ active engagement in water management. Afterwards, an interactive participatory map activity took place, which enabled the study site’s characterization according to key-stakeholders’ perception, knowledge, and expertise on water management issues in the area. Stakeholders collaborated in groups and filled maps of the study area with significant spatial data and information. Participants were asked to express their common vision on Malia in an entertaining puzzle activity.

The aforementioned interactive sessions enabled the extraction of the raised water issues in Malia as well as the suggestion of possible options . The need for sustainable and balanced development taking into account principles of law and equal accessibility for all was specifically noted by stakeholders. Stakeholders evaluated the Living Labs as an innovative interactive and interesting way of exchanging views among institutions and citizens, through participation and technological means. Living Labs are expected to provide significant information exchange among institutions and actors and provide realistic and socially acceptable suggestions for the local community.

Stakeholders are directly involved and motivated to maintain their active engagement in a long-lasting process via future Living Labs in Malia. Such actions increase governance capacity by addressing people’s skills in jointly decision-making and engaging stakeholders in a social learning process through participation. Actions that encourage dialogue among different actors and use innovative mediation techniques form the best options to improve and integrate water governance.

Keywords: Living Labs; Innovative governance; Water resources management; Stakeholder mapping; Social learning processes; Stakeholders’ engagement

The PRIMA programme is an Art.185 initiative supported and funded under Horizon 2020, the European Union’s Programme for Research and Innovation.

The project is funded by the General Secretariat for Research and Technology of the Ministry of Development and Investments under the PRIMA Programme. PRIMA is an Art.185 initiative supported and co-funded under Horizon 2020, the European Union’s Programme for Research and Innovation.

How to cite: Karatzas, G., Vozinaki, A.-E., Trichakis, I., Anyfanti, I., Stylianoydaki, C., Varouchakis, E., Goumas, C., Roggero, P. P., Mellah, T., Akrout, H., and Jomaa, S.: Living Labs towards sustainable groundwater management: case study in Malia, Crete, Greece, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7941, https://doi.org/10.5194/egusphere-egu21-7941, 2021.

Models calibrated on the past are often used to predict future hydrological behavior in a changing world, disregarding that hydrological systems, hence model parameters, will change as well. Even if we are aware of the non-stationarity of hydrological systems, we are impeded by our limited knowledge on how to meaningfully implement this in hydrological models. Yet, ecosystems are likely to adapt in response to climate change and other species might become dominant, both under natural and anthropogenic influence. The root-zone storage capacity of ecosystems is an important hydrological parameter, which ecosystems can adjust in response to climatic change. In this study, we propose a top-down approach, which directly uses projected climate data to estimate how vegetation adapts its root-zone storage capacity at the catchment-scale, in response to changes in magnitude and seasonality of hydro-climatic variables. In order to make reliable estimates of hydrological behavior of future ecosystems, we exchange space-for-time, whereby the Budyko characteristics of different dominant ecosystems in sub-catchments are used to simulate the behavior of potential future land-use change. We hypothesize that predicted changes of the hydrological response as a result of global warming are more pronounced when explicitly considering changes in the sub-surface system properties induced by vegetation adaptation to changing environmental conditions. We test our hypothesis in the Meuse basin in four scenarios designed to predict the hydrological response to +2°C global warming in comparison to current-day reference conditions using a process-based hydrological model with (1) a stationary system, i.e. no changes in the root-zone storage capacity of vegetation and historical land use, (2) an adapted root-zone storage capacity in response to a changing climate but with historical land use, and (3,4) an adapted root-zone storage capacity considering two hypothetical changes in land use from coniferous plantations/agriculture towards broadleaved forest and vice-versa. We found that the larger root-zone storage capacities (+33%) in response to a more pronounced seasonality with drier summers under +2°C global warming strongly alter seasonal patterns of the hydrological response, with an overall increase in mean annual evaporation (+4%), and a decrease in recharge (-6%) and streamflow (-7%), compared to predictions with a stationary system. Through the integration of a time-dynamic representation of changing vegetation properties in hydrological models, we address the 19^th Unsolved Problem in Hydrology (Blöschl et al., 2019) and move towards more reliable hydrological predictions under change.

Blöschl, G., Bierkens, M. F. P., Chambel, A., Cudennec, C., Destouni, G., Fiori, A., et al. (2019). Twenty-three unsolved problems in hydrology (UPH) – a community perspective. Hydrological Sciences Journal, 64(10), 1141–1158. https://doi.org/10.1080/02626667.2019.1620507

How to cite: Bouaziz, L., Aalbers, E., Weerts, A., Hegnauer, M., Buiteveld, H., Lammersen, R., Stam, J., Sprokkereef, E., Savenije, H., and Hrachowitz, M.: The importance of ecosystem adaptation on hydrological model predictions in response to climate change, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4058, https://doi.org/10.5194/egusphere-egu21-4058, 2021.

Ecosystem functioning of habitats at land-water interfaces, such as riparian forests and intertidal salt marshes or mangroves is predominantly driven by inundation. Whereas seasonality of ecological processes (i.e. phenology) and of hydrological extremes/events have been relatively well studied independently from each other their interdependence remains largely unknown. Filling this knowledge gap may become especially important in a changing climate as the timing of ecological and abiotic processes is already changing, often independently from each other. As these ecosystems are increasingly praised as Nature-based Solutions, predicting the ecosystem functioning of riparian forests and coastal wetlands under future climate change is crucial.

Here, we will highlight the importance of match and mismatch of ecological and hydrological processes through a range of experiments and field observations in coastal wetlands from the single seedling to the ecosystem level. For riparian floodplains of Europe, we will show how the temporal relationships between flooding and thermal growing season have already changed in past decades, with currently unknown consequences. Finally, we will showcase methodological advances in field monitoring to better study these timing effects and offer conceptual insights to identify tipping points of ecosystem change along land-water interfaces.

This presentation will focus on UPH ‘interfaces’ and ‘variability’.

How to cite: Balke, T., Vovides, A., Ladd, C., Basyuni, M., and Nilsson, C.: Effects of flood timing on vegetated riparian and coastal habitats in a changing climate, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3095, https://doi.org/10.5194/egusphere-egu21-3095, 2021.

The challenge of deciphering connections between groundwater systems and surface water bodies and by extension connections to hydroclimate represent major unsolved questions in the hydrology community. Within the UPH framework, under the Interfaces in hydrology theme, this includes aspects of both questions twelve and thirteen. In arid regions, disentangling these processes is an especially difficult challenge due to the large spatial and temporal scales over which these systems are integrated. Yet we must improve our understanding if we are to use water sustainably in these landscapes. In the dry Andes, very deep water tables develop groundwater flow paths with long transit times, often crossing topographic boundaries before emerging at basin floors. These factors combined with the complex evaporite stratigraphy in which surface and groundwaters interact make it quite difficult to close water budgets and quantify groundwater fluxes across hydrological boundaries. As a result, many fundamental questions about connections across these interfaces remain unresolved. This study presents a novel examination of processes controlling fluxes across critical boundaries (groundwater recharge, inter-catchment flow, and riparian/stream/aquifer exchange) by employing a comprehensive set of ~150 ³H samples from waters across the entire dry Andes paired with a large dataset (>1,500 samples) of ¹⁸O, ²H in water and dissolved major ions.

We present an integrated process-based conceptual framework describing the dominant controls on water compartment connections intrinsic to these arid mountain systems. The large range in mean transit times and the persistence of hydrologic features here allow for reliable delineation of multiple distinct source and flow path groupings. Repeat sampling over several years provides further constraints on connections between these compartments and the modern hydroclimate. Our results outline a few novel findings regarding the hydrological attributes of these environments: i) most of the water sustaining both the regional and local hydrological systems is old (0-10 % modern and 100-10000 yrs old) yet modern water (days-10 yrs old) is critical to sustaining many surface water bodies. ii) transit time distributions in specific water compartments (Groundwaters, Springs, Streams, Saline lagoons, and Vegas) are remarkably stable over time and show consistent patterns across the entire plateau; iii) the existence of surface water bodies and their connection to groundwater compartments is regulated by persistent hydrological features (regional flow paths, hydrogeology, fresh-saline interfaces); and iv) sharp divergence in mean residence and transit time of source waters occurs over very short spatial scales (<<1km).  By describing water age distributions and geochemical attributes of these features we define the dominant controls on several discrete water compartments and delineate clear distinctions between long-term average source waters and the decoupling of modern hydroclimate from the hydrologic system as a whole. This analysis represents a significant advancement in our understanding of controls on fluxes across boundaries in arid mountainous regions and freshwater-salt lagoon systems. An improved understanding of the primary controls on water source and transport will allow us to better protect communities and fragile ecosystems from the most damaging potential impacts of water extraction in these environments.

How to cite: Moran, B. J., Boutt, D. F., Munk, L. A., and Fisher, J. D.: Pronounced Water Age Partitioning Between Arid Andean Aquifers and Fresh-Saline Lagoon Systems, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13753, https://doi.org/10.5194/egusphere-egu21-13753, 2021.

Question #20 of the UPH aspires to disentangle and reduce model prediction uncertainty. One feasible approach is to first formulate the relationship between variability (of real-world hydrological processes and catchment characteristics) and uncertainty (of model components and variables), which links the UPH theme of “modelling methods” to “time variability and change” and “space variability and scaling”. Building on this premise, we explored the relationship between runoff generation hypotheses, derived from a large ensemble of catchment model simulations, and catchment characteristics (physiographic, climatic, and streamflow response characteristics) across a large sample of 221 Australian catchments. Using ensembles of 10⁶ runs of SIMHYD model for each catchment, runoff generation hypotheses were formulated based on the interaction of 3 runoff generating fluxes of SIMHYD, namely intensity-based, wetness-based, and slow responses. The hypotheses were derived from model runs with acceptable performance and sufficient parameter sampling. For model performance acceptability, we benchmarked Kling-Gupta Efficiency (KGE) skill score against the calendar day average observed flow, a catchment-specific and more informative benchmark than the conventional observed flow mean. The relative parameter sampling sufficiency was also defined based on the comparative efficacy of two common model parameterisation routines of Latin Hypercube Sampling and Shuffled Complex Evolution for each catchment. Across 186 catchments with acceptable catchment models, we examined the association of uncertain runoff generation hypotheses (i.e. ensemble of modeled runoff fluxes) with 22 catchment attributes. We used the Flux Mapping method (https://doi.org/10.1029/2018WR023750) to characterise the uncertainty of runoff generation hypotheses, and a range of daily and annual summary statistics to characterise catchment attributes. Among the metrics used, Spearman rank correlation coefficient (R_s) was the most informative metric to capture the functional connectivity of catchment attributes with the internal dynamics of model runoff fluxes, compared to linear Pearson correlation and distance correlation coefficients. We found that streamflow characteristics generally have the most important influence on runoff generation hypotheses, followed by climate and then physiographic attributes. Particularly, daily flow coefficient of variability (Qcv) and skewness (Q Skewness), followed by the same summary statistics of precipitation (Pcv and P Skewness), were most important. These four attributes are strongly correlated with one another, and represent the dynamics of the rainfall-runoff signal within a catchment system. A higher Pcv denotes a higher day-to-day variability in rainfall on the catchment, responded by a higher Qcv flow response. A higher variability in rainfall propagates through the catchment model and translates into a higher degree of equifinality in model runoff fluxes, which implies larger uncertainties of runoff generation hypotheses at catchment scale, and hence a greater challenge for reliable/realistic simulation and prediction of streamflow.

How to cite: Khatami, S., Fowler, K., Peel, M., Peterson, T. P., Western, A., and Kalantari, Z.: On the relationship between the variability of catchment hydroclimate and physiography, and the uncertainty of runoff generation hypotheses, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9888, https://doi.org/10.5194/egusphere-egu21-9888, 2021.

Environmental models, such as hydrological models or water quality models, are incorporate numerical algorithms that describe either empirically or physical-based the large variety of natural processes that govern the flow of water (or other variables) and its components. The purposes of these models range from improving our understanding of the principles of hydrological processes at a catchment scale to making predictions about how anthropogenic activities will influence future water resources. To be applicable, these models require calibration with observed output data, which is most often streamflow for hydrological models. Yet, the complex nature of hydrological processes, on the one hand, and the limited observed data to inform model parameters, on the other hand, evoke the unavoidable equifinality issue in the calibration of these models. This equifinality issue is expressed with the presence of several optimal model parameters that have different values but lead to similar model performance. One way of dealing with this issue is through providing a parameter ensemble with optimal solutions instead of a single parameter set, reported often as parametric model uncertainty.

However, this equifinality issue is far from being solved, as also highlighted by one of 23 Unsolved Problems in Hydrology (UPH). This is particularly the case if more variables than only streamflow are of interest. Our hypothesis is that using more than one dataset for calibrating any environmental model helps reducing the equifinality issue during model calibration and thus improves the identifiability of model parameters. In this review-based study, we present recent examples of hydrological (and water quality) models from literature that have been calibrated within a multiple dataset framework to reduce the equifinality issue. We demonstrate that a multi-dataset calibration yields a better model performance regardless of the complexity of the model. Finally, we show that coupling a multi-dataset model calibration with metaheuristics (such as Monte Carlo or Genetic Algorithm) can help reducing the equifinality of model parameters and improving the Pareto frontier. At the bottom of this study, we outline how such a multi-dataset calibration can lead to better model predictions and how it can help emerging water resources problems due to an emerging climate crisis.

This work contributes to one of the seven major themes of 23 UPH, i.e., Modelling methods. It paths a way forward towards reducing parameter uncertainty in hydrological predictions (UPH question #20) and thus towards improving modelling of hydrologic responses in the extrapolation phase, i.e., under changed catchment conditions (UPH question #19).

How to cite: Finger, D. C. and Sikorska-Senoner, A. E.: Towards improving the Pareto frontier in environmental models using multi-dataset calibrations coupled with metaheuristic methods, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-11996, https://doi.org/10.5194/egusphere-egu21-11996, 2021.

The wise selection of modeling approaches with an appropriate level of complexity for the study objectives is critical for robust inference. In this paper, the structure of a cost-performance grid designed for flood modeling is presented. The grid is developed to compare different flood modeling approaches of variable complexity and to guide on the proper selection of the couple data-model. The methodology involves defining metrics to quantify the three variables: data costs, model costs, and performance. Preliminarily, eighteen flood modeling applications in literature were arbitrarily selected and analyzed to guide on the implementation of the grid. The cost-performance diagram allows tracing a cost-performance curve and grouping applications in 4 zones corresponding to 4 modeling approaches (empirical and geomorphic, hydrological, hydraulic, and coupling). The grid is a tool to support the comparison, classification, and future selection of cost-effective modeling approaches. It is flexible and can be extrapolated to other modeling objectives.

How to cite: Hdeib, R., Moussa, R., Colin, F., and Abdallah, C.: A new cost-performance grid to compare different flood modelling approaches, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10310, https://doi.org/10.5194/egusphere-egu21-10310, 2021.

The uMngeni River Basin supports over six million people, providing water to South Africa’s third largest regional economy. A critical question facing stakeholders is how to sustain and enhance water security in the catchment for its inhabitants. The role of Ecological Infrastructure (EI) (the South African term for a suite of Nature Based Solutions and Green Infrastructure projects) in enhancing and sustaining water and sanitation delivery in the catchment has been the focus of a project that has explored the conceptual and philosophical basis for investing in EI over the past five years.

The overall aim of this project was to identify where and how investment into the protection and/or restoration of EI can be made to produce long-term and sustainable returns in terms of water security assurance. In short, the project aimed to guide catchment managers when deciding “what to do” in the catchment to secure a more sustainable water supply, and where it should be done. This seemingly simple question encompasses complexity in time and space, and reveals the connections between different biophysical, social, political, economic and governance systems in the catchment.

Through the study, we highlight that there is an interdependent and co-constitutive relationship between EI, society, and water security. In particular, by working in spaces where EI investment is taking place, it is evident that socio-economic, environmental and political relations in the catchment play a critical role in making EI investment possible, or not possible.

The study inherently addresses aspects of water quantity and quality, economics, societal interactions, and the governance of natural resources. It highlights that ensuring the availability and sustainable management of water resources requires both transdisciplinary and detailed biophysical, economic, social and development studies of both formal and informal socio-ecological systems, and that investing in human resources capacity to support these studies, is critical. In contrast to many projects which have identified this complexity, here, we move beyond identification and actively explore and explain these interactions and have synthesised these into ten lessons based on these experiences and analyses.

• 1 - People (human capital), the societies in which they live (societal capital), the constructed environment (built capital), and natural capital interact with, and shape each other
• 2 - Investing in Ecological Infrastructure enhances catchment water security
• 3 - Investing in Ecological Infrastructure or BuiIt/Grey infrastructure is not a binary choice
• 4 - Investing in Ecological Infrastructure is financially beneficial
• 5 - Understanding history, legacy and path dependencies is critical to shift thinking
• 6 - Understanding the governance system is fundamental
• 7 - Meaningful participatory processes are the key to transformation
• 8 - To be sustainable, investments in infrastructure need a concomitant investment in social and human capital
• 9 - Social learning, building transdisciplinarity and transformation takes time and effort
• 10 - Students provide new insights, bring energy and are multipliers

How to cite: Jewitt, G., Sutherland, C., Stuart-Hill, S., Taylor, J., Risko, S., Martell, P., and Browne, M.: Enhancing Water Security through Restoration and Maintenance of Ecological Infrastructure:  Lessons From the uMngeni River Basin, South Africa, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-11537, https://doi.org/10.5194/egusphere-egu21-11537, 2021.

Some of the main problems in hydrological sciences are related to how and why river flows change as a result of environmental change, and what are the corresponding implications for society. This has been described as the Panta Rhei context, which refers to the challenge of understanding and quantifying hydrological dynamics in a changing environment, i.e. under the influence of non-stationary effects. The river flow regime in a basin is the result of a complex aggregation process that has been studied by the scaling theory, which allows river basins to be classified as regulated or unregulated and to identify a critical threshold between these states. Regulation is defined here as the basin’s capacity to either dampen high flows or to enhance low flows. This capacity depends on how basins store and release water through time, which in turn depends on many processes that are highly dynamic and sensitive to environmental change. Here we focus on the Magdalena river basin in northwestern South America, which is the main basin for water and energy security in Colombia, and at the same time, it has been identified as one of the most vulnerable regions to be affected by climate change. Building upon some of our previous studies, here we use data analysis to study the evolution of regulation in the Magdalena basin for 1992-2015 based on the scaling theory for extreme flows. In contrast to most previous studies, here we focus on the scaling properties of events rather than on long term averages. We discuss possible relations between changes in the scaling properties and environmental factors such as climate variability, climate change, and land use/land cover change, as well as the potential implications for water security in the country. Our results show that, during the last few decades, the Magdalena river basin has maintained its capacity to regulate low flows (i.e. amplification) whereas it has been losing its capacity to regulate high flows (i.e. dampening), which could be associated with the occurrence of the extremes phases of  El Niño Southern Oscillation (ENSO) and anthropogenic effects, mainly deforestation. These results provide foundations for using the scaling laws as empirical tools for understanding temporal changes of hydrological regulation and simultaneously generate useful scientific evidence that allows stakeholders to take decisions related to water management in the Magdalena river basin in the context of environmental change.

How to cite: Marín, D. E., Salazar, J. F., and Posada-Marín, J. A.: Evidence of river flow regulation loss over time in the Magdalena river basin , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13716, https://doi.org/10.5194/egusphere-egu21-13716, 2021.

Abstract:

Budyko's conceptual framework is recognized in hydrology for its concise and accurate representation of long-term water and energy balances of watersheds. Based on the climate-environment coevolution, Budyko-type models capture the signature of environmental dynamics through climate. Many studies have shown a good correlation between the environmental parameter (u) of Budyko-type models and the vegetation coverage (M), but the analysis of the causal relationships between these two parameters has often received little attention. In this study, Convergent Cross Mapping, a causal discovery method, was applied to identify the causality between u and M from seven nested watersheds (areas ranging between 38 and 21,178 km²) of the Nakanbe River located in West African Sahel. The Budyko-type model developed by Chen and Sivapalan (2020) was forced with the climate data (precipitation, potential evapotranspiration, and actual evapotranspiration) to calculate u values for 11-years moving windows between 1977 and 2018. The vegetation coverage (M) was deduced from the Normalized Difference Vegetation Index. The results showed causal relationships between vegetation coverage and Budyko model parameter (convergence at a positive prediction skill) for all the watersheds. The causal influence detected is reciprocal (M influences u, and u influences M: M⇆u) for four of the seven watersheds studied. These results highlighted the existence and reciprocity of climate-environment interactions at different spatial scales.

Keywords:

Causal relationships, Budyko-type models, climate-environment interactions, Nakanbe River watersheds.

How to cite: Gbohoui, P. Y., Fowé, T., Paturel, J.-E., and Yacouba, H.: Exploring causal relationships between vegetation coverage and the environmental parameter of Budyko-type models in the Nakanbe nested watersheds in West African Sahel, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13542, https://doi.org/10.5194/egusphere-egu21-13542, 2021.

There has been increasing recognition that the global water crisis is due to lack of understanding of wider economic and socio-cultural perspectives, resulted from the intended and/or unintended consequences of co-evolution of coupled human-water systems. In light of such recognition, Panta Rhei Initiative (2013-2022) was proposed to focus on changes in both hydrology and society. Approaching end of this decade, it is time to synthesize the knowledge gained in our understanding of coevolution and prediction of coupled human-water systems. The synthesis will produce a book which includes five parts: (I) Motivation and Overview, (II) Theoretical Foundations and Methodological Approaches, (III) Synthesis of Work Done and Understanding Gained in Specific Application Areas, (IV) Panta Rhei Case Studies, (V) Grand Synthesis and Recommendations. This abstract will present a brief introduction of current progress of Panta Rhei Book.

How to cite: Tian, F., Wei, J., Sivapalan, M., and Bloeschl, G.: Coevolution and Prediction of Coupled Human-Water Systems: A Synthesis of Change in Hydrology and Society , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7670, https://doi.org/10.5194/egusphere-egu21-7670, 2021.

Coupled human water systems (CWHS) are distinctive in their diversity. Humans both affect and are affected by water across multiple, and sometimes interacting spatial, temporal, management and governance scales. These relationships pertain to multiple characteristics of both the human (e.g., culture, institutions, historical processes, power relations, and economic incentives) and water (e.g., abundance, scarcity, quality) components of CWHS. Changes in any of these characteristics might ripple through CWHSs to affect key societal outcomes, such as the distribution of hydrological risk and access to water and sanitation. The complexity of understanding and predicting hydrological and social changes lies in the fact that there are multiple, interwoven CHWS, each of which has been examined through a variety of disciplinary and theoretical perspectives. 
This chapter synthesizes existing CHWS frameworks across the social, environmental and engineering sciences. We first propose a typology for the CHWS themselves by identifying both their defining and differentiating characteristics. We then develop a typology for the frameworks used to study them, based on philosophical perspectives and methodological approaches. We then identify promising approaches (what “worked”) and outstanding gaps for future work on CHWS. Finally, we leverage the two previously defined typologies to propose a general structure around which to synthesize knowledge in the subsequent topical chapters of the book. 

How to cite: Müller, M. F., Rusca, M., Adams, E., Allaire, M., Blöschl, G., Cabello Villarejo, V., Dumas, M., Levy, M., Mukherjee, J., Rising, J., and Yu, D. J.: Theoretical frameworks for understanding and predicting changes in hydrology and society , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-11900, https://doi.org/10.5194/egusphere-egu21-11900, 2021.

Floods are concurrently natural and social phenomena. Though generally represented as “natural calamity” and described as ‘phenomena of an atmospheric, hydrological or oceanographic nature’, floods are strongly dependant on territorial as well as historicized dynamics and negotiations. Moreover, as floods offer aggravated threats in the Anthropocene, marked by unpredictable climatic perturbations, impacting marginalized communities inhabiting vulnerable landscapes, it is imperative to collectively understand human-flood systems to craft sustained solutions. Socio-hydrological contribution on human-floods system, building upon ‘complex web of interactions and feedback mechanisms between hydrological and social processes in settled floodplains’, can be considered a significant advancement from hardcore flood hydrology confined to risk analysis through geomorphological accounting of river systems. With the hydrological science as a background, while the methods of socio-hydrology often rely on quantitative or mathematical modeling approaches to represent the human-floods systems, hydro-social analysis, emanating from political ecology, explores power equations in water-society relationship. Though the hydro-social literature mainly dealt with political and social injustices around utilities in urban landscapes for a long time, recently, the thrust has shifted to study stakeholders’ controversies in river basin (co)management and governance. We are in the process of establishing a team of experts from the physical and social sciences who are asked to provide a synthesis of the existing methodological frameworks on coupled human-flood systems, within the Panta Rhei IAHS initiative. Our work identifies and lays out converging possibilities along multiple paradigms, finally proposing a strong case for “pluralistic floods research” (see Evers et al., 2017, https://doi.org/10.3390/w9120933). We argue that a robust understanding of the human-flood systems imbibing “pluralistic floods research” can meaningfully contribute to ongoing debates on flood risk governance, facilitating spatially-informed and historically-contingent interventions, beyond purely technical approaches.

How to cite: Viglione, A. and Mukherjee, J.: Human-flood systems: Why “pluralistic floods research” is a conceptual breakthrough?, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9163, https://doi.org/10.5194/egusphere-egu21-9163, 2021.

Dynamic interactions between humans and water have produced unanticipated feedbacks, leading to unsustainability. Current water management practices are unable to capture the relevant spatial and temporal detail of the processes that drive the coupled human-water system. Whereas natural and socioeconomic processes occur slowly, local communities and individuals rapidly respond to ensure supply-demand balance. In this context, agricultural human-water systems stand out, as roughly 70% of global water demand is for agricultural uses. Additionally, interactions between humans and agricultural water systems involve many actors and occur at multiple spatial and temporal scales. For example, farmers are influenced by risk perceptions, and decisions made at the farm level influence regional hydrologic and socioeconomic systems, such as degradation and depletion of water sources as well as prices of crops. Regional behaviors, in turn, affect national and international dynamics associated with crop production and trade of associated investments. On the other hand, global and national priorities can also percolate down to the regional and local levels, influencing farmer decision-making through policies and programs supporting production of certain crops and local investments. Over the last decade, relevant phenomena in the coupled agricultural human-water systems have been described, as the irrigation efficiency paradox, reservoir effect, and river basin closure. Along with the globalization in the food market, attempts have been taken to developing and applying benchmarks for water-efficient food production, focusing on water productivities, water footprints and yield gaps for agricultural products. Furthermore, significant advancements have been achieved by incorporating social dimensions of agricultural human-water systems behavior. Fusion of quantitative datasets via observations, remote sensing retrieval, and physically-based models has been explored. Advancements have also been made to capture qualitative or relatively intangible concepts of community values, norms, and behaviors, by interacting with stakeholders, identifying the most important elements of their environments, and incorporating these insights into socio-hydrological models. Based on what has been done during the IAHS Panta Rhei decade and what we have learned, and despite recent efforts towards a more comprehensive understanding of the effects of human interventions in agricultural systems, several challenges persist, of which we highlight: 1) Identification of the cross-scale causal effect on agricultural water uses; 2) Quantification of human behavior uncertainties shaped by social norms and cultural values; 3) Development of a high spatial and temporal resolution global dataset.

How to cite: Medeiros, P., Chen, X., Gunda, T., van Oel, P., Vico, G., Marston, L., O’Keeffe, J., Yang, E., Liu, S., Roobavannan, M., Gopalakrishnan, S., Gonzalez-Piedra, J. I., Castilla-Rho, J., Cudennec, C., and Sivapalan, M.: Agricultural human-water systems: challenges, advances, and knowledge gaps, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12873, https://doi.org/10.5194/egusphere-egu21-12873, 2021.

Transboundary rivers flow across political boundaries, requiring riparian countries to share a complex network of environmental, economic, political, social and security interdependencies. Transboundary river fluctuates in both space and time, and have multiple and conflicting demands on its uses, which have often resulted in tensions between riparian countries. Conflict and cooperation is thus an emergent phenomena of this co-evolved human-water systems. The choice of cooperative or conflictive behaviours from riparian countries is not only related to the nature of the water issue itself, but it attains more to the political, cultural, institutional, and socioeconomic conditions of the upstream and downstream countries involved. Understanding of the feedback mechanism is thus needed to be able to develop the understanding of how different actors cake to cooperation of conflict and knowledge to manage it effectively. As part of Panta Rhei Synthesis book, this study provides case study of transboundary human-water system by reviewing knowledge of conflict and cooperation dynamic from various disciplines, existing models and frameworks developed.  

How to cite: Wei, J. and Elshorbagy, A.: Transboundary human-water systems, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16494, https://doi.org/10.5194/egusphere-egu21-16494, 2021.

The U.S. Great Plains low-level jet (LLJ) is active on 26% and 62% of May-September days in the northern and southern Plains, respectively. Characterized by a diurnally-oscillating low-level wind maximum below 700 hPa, large vertical wind shear, and enhanced atmospheric moisture convergence, LLJs have been shown to fuel extreme wind- and precipitation generating mesoscale convective systems. Overall, they explain 30-50% of May-September precipitation in the Plains. The considerable societal impacts of LLJs, which span agriculture, severe weather, and wind energy, have long motivated meteorologist-led investigations into their dynamics and predictability. The sensitivity of LLJs to regional soil moisture gradients was established over thirty years ago. However, it was only recently that our work provided the first estimates of the added-value of satellite soil moisture data assimilation (DA) to LLJ forecasts.

In this presentation, we review and expand upon our previous analysis of 75 NASA Unified WRF LLJ case studies simulated with- and without weakly-coupled NASA Soil Moisture Active Passive (SMAP) soil moisture DA. Of the 75-jet cases, 43 are uncoupled LLJs and 32 are coupled LLJs. Their dynamical classification corresponds with the probable efficacy of land data assimilation. Cyclone-induced coupled LLJs, found in the warm sector of frontal systems, are strongly driven by synoptics and less likely to be influenced by land forcing. Conversely, uncoupled LLJs that occur during quiescent conditions of an anticyclonic high pressure ridge system are likely to be more strongly affected by terrain and soil moisture gradient-induced circulations.

It is shown that SMAP DA is generally more effective in uncoupled LLJ cases. However, significant SMAP DA-induced wind speed differences are noted for both LLJ types at their core and exit regions. Notably, the range of SMAP DA-induced wind speed differences between LLJs of the same class (i.e., uncoupled LLJs) is comparable to the range of differences between LLJs of different classes (i.e., coupled vs. uncoupled). Follow-on analyses presented here address the question of what differs between LLJs with small and large SMAP DA effects. Specifically, we explore attribution of event-scale differences in the added-value of SMAP DA to factors including SMAP spatial coverage, antecedent soil moisture, and the strength of synoptic forcing. Finally, a closer look is given to the verification of jet exit region SMAP DA-induced wind speed shifts using Rapid Refresh.

How to cite: Ferguson, C. R., Agrawal, S., and Bosart, L. F.: The importance of satellite soil moisture assimilation for low-level jet forecasts, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2862, https://doi.org/10.5194/egusphere-egu21-2862, 2021.

Land surface models are important tools to improve our understanding of interacting ecosystem processes, but their predictions are associated with uncertainties related to model forcings, parameters and process simplifications. As high-quality observations become more and more available, they can be used to constrain the uncertainty of land surface model predictions. In this study, we use data assimilation for the fusion of data into the Community Land Model 5.0 (CLM5). CLM5 simulates a broad variety of important land surface processes including moisture and energy partitioning, surface runoff, subsurface runoff, photosynthesis and carbon and nitrogen storage in vegetation and soil. Here, we focus on water movement in soils and related soil hydraulic parameters and assimilate in-situ soil moisture data into CLM5 to improve the estimate of model states and soil hydraulic parameters. To do this, we have coupled the Parallel Data Assimilation Framework (PDAF) with CLM5. This coupling is based on the online variant of PDAF, i.e., data assimilation occurs during simulation runtime in the main memory and not via input/output files. Online coupling requires modification of the model source code, but we aim to keep the modifications to the CLM5 code minimal so that maintenance of the ongoing CLM5 developments remains straightforward. To this end, our approach reuses the existing CLM5 ensemble mode with only necessary adjustments to connect the PDAF parallel communicators. Furthermore, we developed the coupling in the framework of the Terrestrial System Modeling Platform (TSMP). TSMP is a highly modular modeling system for the fully integrated soil-vegetation-atmosphere system. To illustrate the potential of this coupling, we use the ensemble Kalman Filter to perform simultaneous state and parameter updates in a forest headwater catchment.

How to cite: Strebel, L., Bogena, H., Vereecken, H., and Hendricks Franssen, H.-J.: Coupling the Community Land Model 5.0 with the Parallel Data Assimilation Framework, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-11805, https://doi.org/10.5194/egusphere-egu21-11805, 2021.

Land surface characteristics and processes may have complex interactions with the physical and dynamical processes of the atmosphere. However, adequate methods for systemically understanding individual processes of the nonlinearly coupled land-atmosphere continuum are still rare. Therefore, in this study, the age-weighted evaporation tagging approach of Wei et al. (2016) and the three-dimensional online atmospheric water budget analysis of Arnault et al. (2016) were implemented into the Weather Research and Forecast (WRF) model. In addition to the total and tagged atmospheric water states of matter, the latter approach was further extended for age-weighted tagged atmospheric water states of matter, thereby providing a prognostic equation of the residence time of state variables in the atmospheric water cycle. This extension allows to systematically quantify the fate of evaporated and transpired water in terms of magnitude, location, composition, and residence time. The extended WRF model was tested for a land use and land cover change study for the Poyang Lake basin, the largest freshwater lake in China. Two hypothetical scenarios, i.e., a dried-up lake and a forest restoration scenario, were simulated and then compared to a real-case control simulation using the original land-use data. The results of the basin-scale precipitation recycling in the context of evapotranspiration partitioning and the modified atmospheric water cycle due to both scenarios will be presented and discussed. We conclude that our newly developed modelling framework and the proposed analysis strategy have the potential to be applied for better understanding and quantifying the nonlinearly intertwined processes between the land and the atmosphere.

References:

Arnault, J., Knoche, R., Wei, J., & Kunstmann, H. (2016). Evaporation tagging and atmospheric water budget analysis with WRF: A regional precipitation recycling study for West Africa. Water Resources Research, 52(3), 1544–1567. https://doi.org/10.1002/2015WR017704

Wei, J., Knoche, R., & Kunstmann, H. (2016). Atmospheric residence times from transpiration and evaporation to precipitation: An age-weighted regional evaporation tagging approach. Journal of Geophysical Research: Atmospheres, 121(12), 6841–6862. https://doi.org/10.1002/2015JD024650

How to cite: Wei, J., Arnault, J., Zhang, Z., Laux, P., Fersch, B., Wagner, S., Dong, N., Yang, Q., Yang, C., Yu, Z., and Kunstmann, H.: How is the atmospheric residence time of evapotranspired water altered with a dried-up lake or a forest restoration scenario and what is the impact on precipiation?, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7368, https://doi.org/10.5194/egusphere-egu21-7368, 2021.

In the year 2018, Central Europe experienced a meteorological drought and a heatwave, which led to a subsequent evolution of a hydrological drought that is still detectable in subsurface water storage anomalies today. Most likely, the drought also led to significant changes in the energy balance between solar radiation, latent and sensible heat fluxes. In conjunction with water scarcity in the subsurface, these changes may lead to feedbacks that mitigate or enforce drought conditions in the context of land-atmosphere coupling. Understanding these feedbacks is of great interest, especially under various large-scale weather patterns that strongly influence the water and energy budgets over Europe at the interannual time scale. We improve our understanding by applying the Terrestrial Systems Modeling Platform (TSMP) over the 12km resolution pan-European CORDEX model domain simulating the water and energy cycles from the groundwater to the top of the atmosphere. TSMP couples a hydrological, land-surface and atmospheric model, facilitating studies of feedbacks between total water storage anomalies, the energy budget and atmospheric processes. To investigate the feedbacks, we performed TSMP ensemble simulations of three anomalously dry water years (September to August) over Central Europe. The ensembles were initialized with the surface and subsurface states of the end of August of the drought years 2011, 2018 and 2019 from an ERA-Interim driven climatology simulated continuously with TSMP from 1989 to 2019. Every ensemble consists of 22 members, each representing a full subsequent water year, sampled from ERA-Interim reanalysis meteorological boundary conditions from 1996 to 2019, thereby simulating the influence of drought conditions over a wide range of large-scale weather patterns that occurred in Europe since 1996. In addition, to illustrate the potential range of feedbacks we also ran idealized experiments with a completely dry or wet subsurface. The results show that drought conditions may have a significant impact on cloud water and solar radiation at interannual timescales. Effects in winter are negligible, while in summer, an impact of the drought conditions of the previous year on cloud water and solar radiation is detectable in all three ensembles. The results suggest that positive feedbacks between dry subsurface water storage anomalies and atmosphere processes are not negligible and may intensify drought conditions also at the interannual time scale.

How to cite: Hartick, C., Furusho-Percot, C., Goergen, K., and Kollet, S.: Exploring the mechanism behind successive droughts: Intensification of continental droughts due to positive feedbacks between subsurface water storage anomalies and atmospheric process, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8625, https://doi.org/10.5194/egusphere-egu21-8625, 2021.

Many observational and modelling studies have highlighted the important role that irrigation plays in the terrestrial hydrological and energy cycle. Land surface models are a key tool to study these interactions, underlining the importance of an accurate representation of irrigation in these models. However, most land surface models either ignore irrigation or represent it in a crude way. Here we improve and evaluate the implementation of irrigation in the Community Terrestrial Systems Model (CTSM), the land component of the Community Earth System Model (CESM). In this improvement, we consider three irrigation techniques (flood, sprinkler and drip), which differ in the amount and way of water applied. By combining global maps of the area equipped for irrigation with the distribution of different irrigation techniques, we represent the transient spatial distribution of irrigation techniques. Subsequently, we evaluate the performance of CTSM with the improved irrigation module. Three experiments are conducted: one with irrigation switched off, the second with the original irrigation module and the third with the improved irrigation module implemented. All three outputs are evaluated against observed or remotely sensed land surface energy fluxes and near-surface climate datasets. We anticipate that the results will reveal how our new irrigation schemes improve or reduce the performance of the land surface model.

How to cite: Yao, Y., Swenson, S., Lawrence, D., Lombardozzi, D., Vanderkelen, I., and Thiery, W.: Evaluation of the new irrigation implementation in CTSM, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4253, https://doi.org/10.5194/egusphere-egu21-4253, 2021.