HS – Hydrological Sciences

HS1.1.1 – The MacGyver session for innovative and/or self made tools to observe the geosphere

EGU21-1120 | vPICO presentations | HS1.1.1

A new low-cost approach to 3-D water temperature monitoring

Eva Loerke, Mark E. Wilkinson, Ina Pohle, David Drummond, and Josie Geris

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,, 2021.

EGU21-1530 | vPICO presentations | HS1.1.1

An Imaging Capable, Low Cost IoT Node for River Flood Phenomena

Evangelos Skoubris and George Hloupis

Among all natural disasters, river floods are becoming increasingly frequent. They present high risk and their impact can be fairly destructive and of strong economic, health, and social importance. Key tools to avoid their catastrophic results are the Early Warning Systems (EWS). An EWS usually monitors various physical quantities through a specific hardware, and produce data which after certain processing can detect and estimate the level of the risk.

In the current work we present the concept, the design, the application, and some preliminary data regarding a low cost imaging node, part of an EWS aimed for river floods. This EWS consists of various sensing nodes which are mainly equipped with water presence detectors, water level meters, water temperature sensors, along with the necessary networking capability. The novelty of this new node design is that it utilizes a VGA resolution camera which captures still images of a view of interest. The latter can be for example an implementation prone to defects in case of flood, such as a river basin level road crossing, or a bridge. The images can also provide constant monitoring of the river basin state, i.e. to detect the presence of any unwanted objects (waste or other natural & artificial bring materials). Through image processing the images can even provide some coarse data, i.e. water level measurements by utilizing vertical stripped rods within the field of view of the camera.

The ability to have a camera usually counteracts the IoT characteristics of an electronic device. Nevertheless, in this design the IoT character of the node was not constrained. The nodes have extended power autonomy (several months via Li-Ion battery, optionally solar rechargeable), present a small size, each node is network independent using GSM and LoRaWAN technology. The data usage is minimized by uploading only 2 QVGA images per day in normal operation (can be increased to a maximum of 48 VGA images per day, if required). In case of risk detection the node also supports the actuation of a local warning sign.

How to cite: Skoubris, E. and Hloupis, G.: An Imaging Capable, Low Cost IoT Node for River Flood Phenomena, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1530,, 2021.

EGU21-887 | vPICO presentations | HS1.1.1

Measuring and monitoring trees and forests using a novel IoT approach

Matthew Wilkinson, Michael Bell, Thomas Baer, and Georgios Xenakis

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,, 2021.

EGU21-2289 | vPICO presentations | HS1.1.1

Open source hardware for counting and measuring raindrops

Nick van de Giesen, Rolf Hut, and Dirk van der Lubbe - Sanjuan

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 (, 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,, 2021.

EGU21-2764 | vPICO presentations | HS1.1.1

An easy-to-use, low-cost evaporation protection to collect more reliable stable water isotope data with Teledyne ISCO portable samplers

Jana von Freyberg, Julia L. A. Knapp, Andrea Rücker, Bjørn Studer, Massimiliano Zappa, and James W. Kirchner

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,, 2021.

EGU21-8325 | vPICO presentations | HS1.1.1

Low-Budget Sewage Overflow Monitoring

Caroline Spill, Lukas Ditzel, Nora Brumm, Julia Böhm, and Matthias Gassmann

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,, 2021.

EGU21-8384 | vPICO presentations | HS1.1.1

Water vapour monitoring with E-band microwave links of cellular backhaul

Martin Fencl and Vojtech Bares

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,, 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,, 2021.

EGU21-9371 | vPICO presentations | HS1.1.1

A new approch for measuring ocean vertical velocities

Jean-Luc Fuda, Stéphanie Barrillon, Andrea Doglioli, Anne Petrenko, Gerald Gregori, Roxanne Tzortzis, Caroline Comby, Melilotus Thyssen, Michel Lafont, Nagib Bhairy, Denis Malengros, Dorian Guillemain, and Chistian Grenz

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,, 2021.

EGU21-9421 | vPICO presentations | HS1.1.1

Underwater annular irradiance: New concept to measure the light diffuse attenuation coefficient through the KduSTICK, a Do-It-Yourself device

Carlos Rodero, Raul Bardaji, Joaquin Salvador, Estrella Olmedo, and Jaume Piera

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,, 2021.

EGU21-10906 | vPICO presentations | HS1.1.1

Continuous water level monitoring using time-lapse imagery

Simone Noto, Flavia Tauro, Andrea Petroselli, Ciro Apollonio, Gianluca Botter, and Salvatore Grimaldi

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,, 2021.

EGU21-13082 | vPICO presentations | HS1.1.1

Improving the efficiency of HYPROP by controlling temperature and air flow

Ioannis Daliakopoulos, Dimitrios Papadimitriou, and Thrassyvoulos Manios

Soil water characteristic curve (SWCC) is a critical relationship with application in drainage, irrigation, soil physical behavior, and modeling water and nutrient transport. However, constructing the SWCC is tedious, time consuming, and often inaccurate. Recently, METER Group, Inc. (USA) introduced the HYPROP2© measurement system which allows semi-automated direct measurements of water retention and conductivity pairs over a relatively wide range of pressure head values using the Extended Evaporation Method (EEM) (Schindler et al., 2010). Nevertheless, even with HYPROP, depending on soil type, measurement of the characteristic curve under ambient conditions requires from 2 (clay) to 10 days (peat and sand) (Schindler et al., 2010). To expedite the method, here we propose a modification of HYPROP that facilitates consistent temperature and air flow around and over the soil sample ring to ensure constant evaporation from the soil sample. The prototype regulates soil sample temperature using two 5X10 cm heating pads (SparkFun Electronics, USA) insulated with glass fiber belt around the sample ring. Air flow is regulated by a blushless 40x40x10 mm fan (SparkFun Electronics, USA) mounted over the HYPROP apparatus. Temperature and fan speed are regulated by a DC step down module based on the LM2596 Simple Switcher® Power Converter (Texas Instruments, USA). All parts are 5 VDC and can be conveniently powered by USB. Here we compare the time required for HYPROP to estimate the SWCC curve for two hydroponic substrates (cocodust and perlite) and show that the resulting curve is identical, while the time required to process the sample is significantly reduced. These results, as well as extensive testing conducted by Daliakopoulos et al. (2020) and Papadimitriou et al. (2020) show that the HYPROP method can greatly benefit in terms of efficiency from including a similar system to control the evaporation rate.


Daliakopoulos, I.Ν., Papadimitriou, D., Matsoukas, T., Zotos, N., Moysiadis, H., Anastasopoulos, K., Mavrogiannis, I., Manios, T., 2020. Development and Preliminary Results from the Testbed Infrastructure of the DRIP Project. Proceedings 30, 64.

Papadimitriou, D., Kontaxakis, E., Daliakopoulos, I., Manios, T., Savvas, D., 2020. Effect of N:K Ratio and Electrical Conductivity of Nutrient Solution on Growth and Yield of Hydroponically Grown Golden Thistle (Scolymus hispanicus L.). Proceedings 30, 87.

Schindler, U., Durner, W., von Unold, G., Mueller, L., Wieland, R., 2010. The evaporation method: Extending the measurement range of soil hydraulic properties using the air-entry pressure of the ceramic cup. J. Plant Nutr. Soil Sci.


This research has been co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship, and Innovation, under the call RESEARCH-CREATE-INNOVATE (project codes: T1EDK-03372, Τ1EDK-04171)

How to cite: Daliakopoulos, I., Papadimitriou, D., and Manios, T.: Improving the efficiency of HYPROP by controlling temperature and air flow, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13082,, 2021.

EGU21-13142 | vPICO presentations | HS1.1.1

Automated high resolution rain water sampler for stable water isotope monitoring 

Christoff Andermann, Markus Reich, Torsten Queißer, Bijay Puri, Oliver Rach, Niels Hovius, and Dirk Sachse

With global change, one of the largest short-term threats to our societies comes from changes in the hydro-meteorological cycle: droughts, flooding and potentially increasing extreme rain events may have far greater direct impact on humans than rising temperatures alone. These changes often have sever consequences and widespread impact on society and ecosystems, yet they are difficult to track, trace and measure in order to fully understand the underlying process of delivering moisture and recharging water reservoirs. Only through the comprehensive monitoring of precipitation waters in space and time can we improve our process understanding and better predict the direction and magnitude of future hydro-meteorological changes, in particular on regional spatial scales. However, no commercial automated sampling solution exists, which fulfills the quality criteria for sophisticated hydrochemical water analysis.

Here, we present an new developed automatic precipitation water sampler for stable water isotope analysis of precipitation. The device is designed to be highly autonomous and robust for campaign deployment in harsh remote areas and fulfills the high demands on sampling and storage for isotope analysis (i.e. sealing of samples from atmospheric influences, no contamination and preservation of the sample material). The sampling device is portable, has low power consumption and a real-time adaptable sampling protocol strategy, and can be maintained at distance without any need to visit the location. Furthermore, the obtained water samples are not restricted to isotope analysis but can be used for any type of environmental water analysis. The current configuration can obtain 165 discrete rainwater samples with a minimum timely resolution of 5min or volume wise 2mm of rainfall.

The device was tested in several evaluation and benchmarking cycles. First lab tests with dyed waters and waters with strongly differing isotopic signature demonstrate that the device can obtain, store and conserve samples without cross contamination over long periods of time. The device has been tested so far under several conditions, e.g. heavy summer thunderstorms with more than 50mm/24h of rainfall, sustained winter rainfall and in cold conditions involving melting of snow. Furthermore, we run a benchmark test with several devices in parallel. Finally, in October 2020, we had installed six devices, in collaboration with Germany's National Meteorological Service (Deutscher Wetterdienst DWD), in a South-West to North-East transect across the Harz mountains in Germany. The transect covers ~ 100km distance along the main orographic gradient.

This automated rainwater sampler provides an economic and sophisticated technological solution for monitoring moisture pathways and water transfer processes with the analytical quality of laboratory standard measurements on a new level of temporal and spatial resolution.

How to cite: Andermann, C., Reich, M., Queißer, T., Puri, B., Rach, O., Hovius, N., and Sachse, D.: Automated high resolution rain water sampler for stable water isotope monitoring , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13142,, 2021.

EGU21-13337 | vPICO presentations | HS1.1.1

A Low-Cost Turbidity Sensor for Deployment in Rivers

Peter Molnar, Jessica Droujko, and Marius Floriancic

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,, 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,, 2021.

EGU21-16254 | vPICO presentations | HS1.1.1

OpenDroneMap360, an affordable DIY open-source hardware and software workflow for 3D point clouds and terrain models

Hessel Winsemius, Stephen Mather, Ivan Gayton, and Iddy Chazua

The state of the art in terrain data generation is Light Detection And Ranging (LiDAR). LiDAR is usually deployed through manned or unmanned aerial vehicles. As typical payloads are high, an aircraft with LiDAR needs to be significant in size. Therefore, LiDAR is currently only done by specialized companies with expensive equipment, and cannot be deployed by local service providers in low income countries, despite the plethora of use cases for its data.


A promising avenue to replace LiDAR is photogrammetry. It can be applied with much lighter and more affordable aircrafts and its use to provide extensive terrain datasets is steadily increasing. The scalable open-source software OpenDroneMap allows for extending datasets to very large amounts. Photogrammetry however, cannot penetrate vegetation, and (as is the case with LiDAR) does not resolve ground terrain in obscured areas such as dense urban areas with narrow alleys.


That is why we are developing OpenDroneMap360, a free and open-source DIY hardware-software camera-ball platform for collection of high quality photos with any carrier you can think of. This can be a self-built drone, a backpack rig or another setup we haven’t considered yet, equipped with enough lenses to discover any ground that you can think of. Our current hardware offers a backpack rig with a total of 7 lenses and contains a parts list, 3D-printable hull, connection scheme, software deployment and a Sphinx manual how to build, deploy and operate the rig. The technology contains raspberry pi cameras connected to raspberry pi zeros for each lens, a Ardusimple u-blox ZED-F9P GNSS chipset, a raspberry pi4 to instruct the cameras, collect GPS positions, and perform file and data management, and a LiPo battery solution. The entire setup is available on


How to cite: Winsemius, H., Mather, S., Gayton, I., and Chazua, I.: OpenDroneMap360, an affordable DIY open-source hardware and software workflow for 3D point clouds and terrain models, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16254,, 2021.

HS1.1.2 – Advances in river monitoring and modelling for a climate emergency: data-scarce environments, real-time approaches, inter-comparison of innovative and classical frameworks, uncertainties, harmonisation of methods and good practices

EGU21-10778 | vPICO presentations | HS1.1.2

Generating videos of synthetic river flow for the evaluation of image-based techniques for surface velocity determination

Guillaume Bodart, Jérôme Le Coz, Magali Jodeau, and Alexandre Hauet

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,, 2021.

EGU21-221 | vPICO presentations | HS1.1.2

An improvement to the ANN-enhanced flow rating method

Bernhard Schmid

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.    



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,, 2021.

EGU21-1558 | vPICO presentations | HS1.1.2

The use of a 3rd U/S or D/S sensor in Salt Dilution Flow Measurements

Gabe Sentlinger

Salt Dilution flow measurement is relatively accurate and easy way to measure flow in turbulent waterways.  However, it’s accuracy and precision are governed by the Signal to Noise (SNR) Ratio, which can be very low in urban, sub-urban, and rural waterways due to a highly variable BackGround specific Electrical Conductivity (BG ECT) signal.  Conventionally, more salt is added to the waterway to overcome the noise in the BG ECT.  The “noise” is a combination of random noise, which is amplified by the typically high BGECT (>500 uS/cm), but also lower frequency noise that changes on the same time scale as the salt breakthrough curve.  To compensate for the changing BG ECT, we have employed a 3rd UpStream (U/S) probe to track the BG ECT, along with algorithms to transform the signal in 3 domains: magnitude (ECT offset), time (transit time of pulse), and frequency (to compensate for storage in the waterway).  Additionally, we have tested the use of a 3rd DownStream (D/S) probe to measure cross-channel variance when mixing is not complete in order to achieve a reasonable flow estimate.  Results are compared and discussed.

How to cite: Sentlinger, G.: The use of a 3rd U/S or D/S sensor in Salt Dilution Flow Measurements, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1558,, 2021.

EGU21-5902 | vPICO presentations | HS1.1.2 | Highlight

`Flowonthego' - flow tracking technology on your smartphone 

Jonathan Higham and Andrew Plater

Over the past few years, smartphone devices have become so powerful that in your pocket, not only do you have a device which can communicate with people across the world, the sheer power of these devices has now also brought a new frontier in scientific measurements. In this presentation, we present our smartphone app 'flowonthego', a technology which allows users to determine flow velocities, in almost real-time, from simple video footage. The instantaneous velocity fields are calculated by solving the Lucas-Kanade solutions to the optical flow equations and tracking naturally occurring features. The app also harnesses the potential of augmented reality, making calibration reference and the need tape measures a thing of the past. Furthermore, the app also packs an arsenal of post-processing tools in which users can understand basic statistics. From preliminary our studies we have found 'flowonthego' is able to match the statistics of commonly used ADCP's while also providing instantaneous full vector fields allowing users to better understand dynamical processing. 

How to cite: Higham, J. and Plater, A.: `Flowonthego' - flow tracking technology on your smartphone , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5902,, 2021.

EGU21-2116 | vPICO presentations | HS1.1.2 | Highlight

The Video Globe Challenge 2020, a video streamgauging race during the Covid-19 lockdown

Jérôme Le Coz, Alexandre Hauet, and Aurélien Despax

The strict lockdown imposed by the Covid-19 health crisis motivated the French-speaking hydrometry network Groupe Doppler Hydrométrie (GDH) to organise a new type of hydrometric intercomparison, based on video gauging. Between 15 April and 10 May 2020, the Video Globe Challenge 2020 was run in 8 stages corresponding to 8 videos taken from the ground (5 cases) or from a drone (3 cases), each coming with a reference discharge measurement (6 ADCP gauging, 1 dilution gauging, 1 calibration curve). These eight cases present various flows, measurement conditions and operating difficulties. The data were provided by EDF, DREAL Auvergne-Rhône-Alpes, NVE (Norway) and DNRME Queensland (Mark Randall, Australia).

For each stage, around 25 competitors participated by submitting their discharge result, their surface velocity coefficient (a.k.a alpha) estimate and their parameters, with the hope of getting as close as possible to the reference discharge. Several velocimetry techniques and software tools were used: from visual spotting and manual processing, in Flowsnap (Tenevia), Excel or Barème, to specialised software, mainly Fudaa-LSPIV (EDF/INRAE) but also SSIVSuite (Photrack), PIVlab, and Opyf (EPFL/INRIA, local optical flow). The general classification (smaller sum of percentage deviations to discharge references), points classification (smaller sum of ranks), sniper classification (best visual velocimetry) and young rider classification (for students) awarded the yellow, green, polka dot and white jerseys, respectively.

The Challenge 2020 has been rich in lessons, notably by illustrating several important sources of error for video gauging and the possible parries that the user can deploy (or not...). The exercise was as useful for training and coaching the participants (often beginners) as it was for identifying the improvements to be expected in procedures and software. The results highlight some operator-related error sources which need to be minimized by developing more guided or automated parameter settings, and more robust velocimetry algorithms. They also illustrate the typical uncertainty levels of such measurements.

The cultural aspects were not left out, revealing historical facts and hydrometry-related feats about the rivers visited, e.g. Julius Caesar wading the river to join the druids in the sanctuary of Seranos, Viking Stør Åne the Blue breaking the ice cover to prevent rating shift, or Sir Herbert inventor of the anti-crocodile waders. The official history of hydrometry conceals many unsuspected mysteries that have yet to be revealed...

How to cite: Le Coz, J., Hauet, A., and Despax, A.: The Video Globe Challenge 2020, a video streamgauging race during the Covid-19 lockdown, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2116,, 2021.

EGU21-10330 | vPICO presentations | HS1.1.2

Estimating the hydrodynamic and morphodynamic characteristics using Entropy theory at the confluence of Negro and Solimões Rivers

Farhad Bahmanpouri, Silvia Barbetta, Carlo Gualtieri, Marco Ianniruberto, Naziano Filizola, Donatella Termini, and Tommaso Moramarco

When two mega rivers merge the mixing of two flows results in a highly complex three-dimensional flow structure in an area known as the confluence hydrodynamic zone. In the confluence zone, substantial changes occur to the hydrodynamic and morphodynamic features which are of significant interest for researchers. The confluence of the Negro and Solimões Rivers, as one of the largest river junctions on Earth, is the study area of the present research. During the EU-funded Project “Clim-Amazon” (2011-2015), velocity data were collected using an ADCP vessel operating under high and low flow conditions in different locations at that confluence (Gualtieri et al., 2019). By applying the Entropy theory developed by Chiu (1988) for natural channels and simplified by Moramarco et al. (2014), the two-dimensional velocity distribution, as well as depth-averaged velocity, were calculated at the different transects along the confluence zone, using only the surface velocities observation. The estimated data yielded 6.6% and 6.9% error percentage for the discharge data related to high and low flow conditions, respectively, and 8.4% and 8.3% error percentage for the velocity data related to high and low flow conditions, respectively. Regardless of the flow condition, these preliminary results also suggest the potential points at the confluence zone for the maximum local scouring. The findings of the current research highlighted the potential of Entropy theory to estimate the flow characteristics at the large river’s confluence, just starting from the measure of surface velocities. This is of considerable interest for monitoring high flows using no-contact technology, when ADCP or other contact equipment cannot be used for the safety of operators and risks for equipment loss.


Keywords: Amazon River, Negro/Solimões Confluence, Entropy Theory, Velocity Distribution, Local Scouring


Gualtieri, C., Ianniruberto, M., Filizola, N. (2019). On the mixing of rivers with a difference in density: the case of the Negro/Solimões confluence, Brazil. Journal of Hydrology, 578(11), November 2019, 124029,

Chiu, C. L. (1988). “Entropy and 2-D velocity distribution in open channels”. Journal of Hydrologic Engineering, ASCE, 114(7), 738-756

Moramarco, T., Saltalippi, C., Singh, V.P. (2004). “Estimation of mean velocity in natural channels based on Chiu’s velocity distribution equation”. Journal of Hydrologic Engineering, ASCE, 9 (1), pp. 42-50

How to cite: Bahmanpouri, F., Barbetta, S., Gualtieri, C., Ianniruberto, M., Filizola, N., Termini, D., and Moramarco, T.: Estimating the hydrodynamic and morphodynamic characteristics using Entropy theory at the confluence of Negro and Solimões Rivers, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10330,, 2021.

EGU21-14199 | vPICO presentations | HS1.1.2

Satellite altimeter to estimate discharge of the Ganga River

Atul Kumar Rai and Kumar Gaurav

We use satellite altimeter data to estimate average monthly discharge at seven different locations in the middle and lower parts of the Ganga River. We have obtained the water level from different satellite altimeter mission ERS-2 (1995 - 2007), Envisat (2002 - 2010), and Jason-2 (2008 - 2017) through publicly available databases Hydroweb and DAHITI. To make the water level comparable with the gauge stations, we applied the datum and offset correction to the altimetry datasets. The corrected water level data well accord with the ground measurements with RMSE values in a range between (22 - 71) cm. 

We then established stage-discharge rating curves from the water-level derived from satellite altimeter and the corresponding discharge measured at the nearest gauge station. We use these rating curves to estimate discharge of the Ganga River in the middle (Kachla bridge, Kanpur, Shahzadpur, Prayagraj and Mirzapur) and lower (Azmabad and Farakka) reaches from the water-level from satellite altimeter. Our estimates of discharge compare with the monthly average discharge recorded at the nearest ground station.

We observed that the uncertainty in the discharge estimate is relatively high in the middle than the lower reaches of the Ganga River. This is probably associated with the low discharge and shallow flow depth of the Ganga River in the middle reaches as compare to the high flow depth and discharge in the lower reaches. Overall performance analysis of statistical parameters (NSE, RSR, PBIAS, and R2), suggests that except for the Kanpur station, our estimates of discharge can be categories into "good" to "satisfactory".

How to cite: Rai, A. K. and Gaurav, K.: Satellite altimeter to estimate discharge of the Ganga River, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14199,, 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,, 2021.

EGU21-136 | vPICO presentations | HS1.1.2

Innovative method for gathering river stage data using only the sound of the water

William Alexander Osborne, Rebecca Hodge, Gordon Love, Peter Hawkin, and Ruth Hawkin

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,, 2021.

EGU21-7513 | vPICO presentations | HS1.1.2

Understanding Toxic Floods - Develop monitoring strategies for affected areas

Catrina Brüll, Holger Schüttrumpf, and Henner Hollert

Floods are natural inundations affecting rivers, lakes, coasts and the open sea. Due to anthropogenic impacts those floods can be modified with pollutants. The pollutants are then transported or dislocated during flood events and can then harm humans and life, society and other. The main objective of the project is to understand the complex and non‐linear processes, effects and long‐term impacts of “Toxic Floods” including the various influences of changing natural and anthropogenic boundary conditions from past to future.

As water/environmental engineers we aim to understand flood-related dispersion of contaminants and contaminated sediment. Therefore, we have a deep look at processes concerning sediment transport, fate and load during flood events. In a further step, it is aimed to describe and quantify the anthropogenic impact in floodplains and medium size river catchments. This knowledge will help to simulate toxic floods and define different scenarios and their effect on the environment.

In collaboration with an interdisciplinary team we can synthesize all outcomes and will be able to develop e.g. smart flood monitoring plans.[CB1] 

How to cite: Brüll, C., Schüttrumpf, H., and Hollert, H.: Understanding Toxic Floods - Develop monitoring strategies for affected areas, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7513,, 2021.

EGU21-8897 | vPICO presentations | HS1.1.2 | Highlight

A Continuous Data Production Approach to Flow Estimation in Canada

Francois Rainville, Alain Pietroniro, Andre Bouchard, Amber Brown, and Douglas Stiff

The world has entered an era of immense water-related threats due to climate warming and human actions.  Changing precipitation patterns, reducing snowpack, accelerating glacial melt, intensifying floods and droughts have made the need for timely hydrometric information indispensable. Climate change thus introduced requirements for adaptive management and timely water resource information at the municipal, regional and national levels. Over the last 10 years, it became evident that demands from users had moved towards best available hydrometric data in near real-time.  As with most hydrometric services around the world, the WSC was a legacy and archive-driven organization that published approved data on an annual basis.  Real-time data was an after-thought simply equated with the application of rating curves onto telemetry water levels, while hydrographers remained focused on approving data months after the facts. To address this challenge, the Meteorological Service of Canada‘s National Hydrological Services, and specifically the Water Survey of Canada (WSC) has developed a near real-time continuous data production system to meet the evolving needs of stakeholders.  To meet this challenge, WSC developed solutions where data would be improved as field-measurements were being acquired. Corrections to data and rating curves are applied within hours of field discharge measurements, allowing for near-real time publication of corrected discharge information.  Moreover, station conditions and performance are constantly monitored with “eyes-on-data” production tools that allow the program to optimize its field visits, costs and data publication. These tools were developed in-house to enable effective network time-management while communicating important information with partner agencies.  This was made possible with a cloud-based hydrometric data production system and modern telecommunications tools.  As a result of this work, the improved near real-time data became the catalyst to revamp a multi-decade approach to final data approval. This improved overall efficiency and is now leading to less delays in the approved data production cycle.  This paper describes the design and implementation of the continuous data production system adopted at WSC and highlights some of the benefits noted since program implementation. This paper also identifies future investments that could help the sustainability of this new system in the long term.

How to cite: Rainville, F., Pietroniro, A., Bouchard, A., Brown, A., and Stiff, D.: A Continuous Data Production Approach to Flow Estimation in Canada, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8897,, 2021.

EGU21-9229 | vPICO presentations | HS1.1.2

Seeding metrics for image velocimetry performances in rivers

Silvano Fortunato Dal Sasso, Alonso Pizarro, Sophie Pearce, Ian Maddock, Matthew T. Perks, and Salvatore Manfreda

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.



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,, 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,, 2021.

EGU21-10378 | vPICO presentations | HS1.1.2

GIS-based multicriteria decision analysis for the environmental assessment of the Pesqueria River in Northeast Mexico, using UAS and multi-spectral imagery 

Diana Laura Mireles Soria, Fabiola Doracely Yépez Rincón, Nelly Lucero Ramírez Serrato, Maria Gabriela Ortiz Martínez, Adrián Leonardo Ferriño Fierro, and Victor Hugo Guerra Cobián

Urbanization is the dominant force shaping social, economic, and environmental life in the 21 century. Urban areas will become essential to achieve the Sustainable Development Goals (SDGs) established by the United Nations in their 2030 Agenda. Local governments must identify the vulnerable ecosystems to make cities inclusive, safe, and resilient (SDG 11). In Latin America, urban rivers are vulnerable ecosystems, negatively impacted by rapid urbanization. Furthermore, detailed geospatial information of urban rivers is not updated frequently, therefore available data doesn’t reflect changes occurring due to rapid urban development processes affecting the quality of water, sediments, or vegetation health. This research uses a GIS-based multicriteria decision analysis (GIS-MCDA) for the environmental assessment of the Pesqueria River as a decision tool to facilitate mitigation focused strategies. The developed method has used the pixel to pixel data from socio-economical, environmental, topographical, geological, and hydrological factors affecting the environmental health of urban rivers. Census data, geological formation or soil type were obtained from official information; reflectance indices and vegetation height were obtained using aerial photogrammetry with near-infrared and red bands; terrain and hydrological analysis used digital elevation models derived from LIDAR; land cover was created using a SENTINEL 2 image; and water quality data was obtained from field sampled raised and analyzed with traditional laboratory analysis of Chemical Oxygen Demand and validated also with official data. Results implied the generation of the thematic maps with ranges from 1 (very low quality) to 5 (very high quality) according to the environmental quality assessment. For the GIS-MCDA, the values of each map were converted to the same scale, each criterion was weighted in function of its importance according to the literature review and the objective of this research, and there were aggregated by the way of a lineal combination. The result is a map that shows the level of mitigation or conservation priority along the river. This map can offer information to the stakeholders in a relatively short time and accelerate the actions aimed to protect the quality of this important urban ecosystem. 

How to cite: Mireles Soria, D. L., Yépez Rincón, F. D., Ramírez Serrato, N. L., Ortiz Martínez, M. G., Ferriño Fierro, A. L., and Guerra Cobián, V. H.: GIS-based multicriteria decision analysis for the environmental assessment of the Pesqueria River in Northeast Mexico, using UAS and multi-spectral imagery , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10378,, 2021.

EGU21-15468 | vPICO presentations | HS1.1.2

Large-Eddy Simulation in LSPIV techniques: the study of surface turbolence

Francesco Alongi, Giuseppe Ciraolo, Enrico Napoli, Dario Pumo, and Leonardo V. Noto

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,, 2021.

EGU21-15531 | vPICO presentations | HS1.1.2

Mapping surface water quality in Myanmar using aquatic drones

Rui Pedroso de Lima, Thom Bogaard, and Robbert De Lange

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,, 2021.

EGU21-7134 | vPICO presentations | HS1.1.2 | Highlight

Riverscape-scale airborne TIR assessment of weirs and riparian cover effects on lowland river temperature 

Baptiste Marteau, André Chandesris, Flavie Cernesson, Kristell Michel, Lise Vaudor, and Hervé Piégay

The development of Airborne Infrared Thermal sensing (TIR) is an example of how technological advancements and the field that they focus on have fostered one another. The pace at which global change is occurring has fed the demand for better understanding of the thermal behaviour of rivers. In turn, the improvement of remote sensing and data processing techniques has provided researchers and managers with new tools to apprehend such aspects at ever larger scales. Still, recent studies have mostly focussed on rivers showing little human alteration, with a particular interest on groundwater–surface water interactions. Lowland streams are scarcely considered when it comes to the study of temperature despite their widespread occurrence, their relatively high degree of disturbance and the risks that they face in the light of temperature rising following climate change. Some of these streams already display critically high maximum summer temperatures and their state is likely to worsen in the future, putting all compartments of biota at risk.

The aims of this project were twofold. We first tested the applicability of airborne TIR to study lowland, slow-flowing stream reaches draining agricultural catchments, some of which being particularly narrow and sinuous. We then sought to understand the role of different environmental factors, observed in such context, on driving river temperature during the warmest days of the year. A number of anthropogenic actions such as clear-cutting of riparian trees, stream rectification and the construction of weirs are likely to influence the longitudinal temperature profile of such streams. By choosing rivers with no or limited groundwater inputs, we were able to quantify the relative role of each of the three tested factors and identify stream sections showing critically high maximum temperature over the summer.

A final step was proposed to upscale these results in order to identify sections of streams showing high risks of reaching critically high summer temperature at a regional network scale. To do so, we used a combination of high resolution land-cover data, digital elevation models and other existing databases (e.g. national inventory of weirs). Identification of the risks in relation with the relative contribution of the different factors is key to process-based river management. This type of output is valuable to river basin managers and decision makers as it can be used to implement targeted restoration initiatives or remediation actions in areas where these have higher chances of being effective.

How to cite: Marteau, B., Chandesris, A., Cernesson, F., Michel, K., Vaudor, L., and Piégay, H.: Riverscape-scale airborne TIR assessment of weirs and riparian cover effects on lowland river temperature , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7134,, 2021.

We present a velocimetry method, which we refer to as Infrared Quantitative Velocimetry (IR-QIV), that uses images of thermal patterns, captured in the infrared, on the surface of rivers or other water bodies, to calculate the time-resolved instantaneous two-dimensional surface velocity field. The method works in all natural light conditions (day or night), and under most weather conditions, by tracking thermal patterns in the surface of the water, and is therefore suitable for a large range of flows and environments. The method, is a form of remote sensing and has significant advantages over traditional (visible-light) PIV (Particle Image Velocimetry) or LSPIV (Large Scale PIV) methods for non-contact measurement of water surface velocity field, as it requires no particle 'seeding' or contact with the water. 

Measurements of instantaneous water flow velocity, from which turbulence metrics are calculated, are important for advancing the understanding of river hydrodynamics beyond fundamentals such as discharge and mean velocity. However, most velocity measurement methods used in the field are capable of measuring at a point, or along a transect, but not over a two-dimensional area. Additionally, tools such as ADCPs generally require temporal and spatial averaging, and therefore can not resolve instantaneous velocities.

Image-based velocimetry methods, including IR-QIV and LSPIV, measure at the surface of the water and over a large area. However, methods that utilize visible-light imagery, such as LSPIV, require external illumination at night, and are challenged by the relatively homogeneous appearance of the water surface, often requiring either naturally occurring, or added 'seeding' particles, that are advected by the flow. Due the intermittent availability of seeding or surface texture, spatial or temporal averaging is often required, limiting the technique to mean velocity measurements.

These limitations do not apply to IR-QIV since under natural conditions a rich texture of temperature differences exist at the surface of the water due to spatially heterogeneous air/water heat exchange. IR-QIV is capable of calculating the instantaneous velocity at high accuracy and resolution, in space and time (centimeter scale, several Hz), over large areas—up to thousands of square meters. The instantaneous velocity measurements can be used to calculate metrics of turbulence to inform applications such as the study of river and other surface water dynamics; small-scale hydrodynamics near flow features such as water diversions, junctions, obstacles, and river bends; fishery management; gas transfer measurement; non-contact estimation of bathymetry, discharge and bed stress, and more.

We present instantaneous velocity and turbulence metrics measured at sites in the Sacramento River, (California, USA,) made using IR-QIV. Additionally, we discuss issues related to uncertainty analysis in velocimetry techniques using oblique camera viewing angles, and pattern tracking in images containing gradients of intensity (not discrete particles), as well as effects of camera noise. These considerations are relevant to all types of large scale image-based velocimetry, regardless of wavelength of image collection (visible-light or IR), and can be used to inform and improve measurements from both fixed and mobile platforms such, as UASs.

How to cite: Schweitzer, S. and Cowen, E.: Large-Scale, Accurate, High Resolution, Measurements of River Surface Velocity and Turbulence Metrics Using Thermal Infrared Images, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13623,, 2021.

EGU21-9825 | vPICO presentations | HS1.1.2

Machine Learning Based Surface Velocimetry

Saber Ansari, Colin D. Rennie, Elizabeth C. Jamieson, Ousmane Seidou, and Shawn P. Clark

Streamflow measurement is of great importance in hydrological research, water management and water infrastructure design. Traditional measurement methods typically employ intrusive techniques, and under certain conditions, obtaining accurate streamflow data with these techniques can be challenging because of safety concerns, especially in some critical circumstances, such as during flood flows. The advent of new instrumentation and technologies, and in particular advances in digital imagery, has led to the emergence of non-intrusive novel image-based technologies that can be used to estimate surface velocity, which in turn can be used to estimate streamflow. Image based technologies, most of which are based on correlation between consecutive images, have the potential for remote and on demand measurements and can provide data when the application of other traditional methods are not possible, reliable or safe. In this study, we present a novel machine learning based optical flow algorithm for streamflow surface velocimetry estimation. The developed algorithm is tested in different flow conditions and using drone and fixed photogrammetry. This method appears to outperform all the other available image-based surface velocimetry approaches (i.e. correlation based and classical optical flow methods). Moreover, this method requires the least user involvement for velocity estimation and thus reduces the impact or arbitrary choices linked to user expertise.

How to cite: Ansari, S., Rennie, C. D., Jamieson, E. C., Seidou, O., and Clark, S. P.: Machine Learning Based Surface Velocimetry, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9825,, 2021.

EGU21-5880 | vPICO presentations | HS1.1.2

OpenRiverCam, open-source operational discharge monitoring with low-cost cameras

Hessel Winsemius, Frank Annor, Rick Hagenaars, Wim Luxemburg, Gijs Van den Munckhoff, Paul Heeskens, Jacquiline Dominic, Pascal Waniha, Yahaya Mahamudu, Halima Abdallah, Ge Verver, and Nick Van de Giesen

River flow observations are notoriously difficult to sustain. A site’s setup,operation and maintenance requires expensive equipment, repetitive field work, and physical contact of instruments and people with water. These issues compounded with the fact that rivers may change their course and behaviour in time, and sites are mostly bound to river crossings such as bridges, make equipment susceptible to theft and vandalism. Over the last decade, several contributors in science have pioneered the use of computer vision methods such as Particle Image Velocimetry, Particle Tracking Velocimetry, and Dense Optical Flow to measure stream velocities, and interpret river flow from short movie snapshots. This has resulted in research oriented software such as FUDAA-LSPIV and a limited set of proprietary software aimed for operational use.

In this contribution we will share and demonstrate the first version of OpenRiverCam, a new fully open-source, user-friendly, low cost and sustainable web-software stack with API to establish and maintain river rating curves (relationships  between geometry and river discharge) in small to medium sized streams based on the aforementioned computer vision methods. The software is co-designed with practitioners from The Netherlands (Waterboard Limburg and KNMI) and Tanzania (Wami - Ruvu Basin Authority and TMA) with the principle that organizations should be able to establish and maintain operational flow monitoring sites and networks at low costs. We demonstrate it through operational feeds from two first sites (Geul River, Limburg - The Netherlands and Chuo Kikuu - Dar es Salaam, Tanzania). 

The software stack will allow a practitioner in hydrology to monitor discharge and maintain a rating curve at low cost with simple yet robust equipment. The required set-up contains a permanent camera providing a view of the river surface and a permanent staff gauge for water level readings. Occasionally a bathymetric survey of the river’s cross section is required that can be performed with standard surveying equipment. The open source software stack is available at no costs and contains a separate python library for processing in case a researcher wishes to use the stack. The software operates with a web-client that connects to a locally or globally deployable server stack (laptop,  desktop, local server or cloud) with database, front-end server and workers, so that scalability is warranted. Other than existing software, OpenRiverCam offers: adding and maintenance of sites and cameras; automated retrieval and processing of movies and rating curve analysis, all in a fully open-source code base. The software can therefore be operated with local people, local devices and open software at any scale leading to job creation and locally sustainable services for National Meteorological and Hydrological Services (NMHS) and their service providers. We plan to extend the software with operational water level measurements and possibly other relevant environmental parameters such as sediment deposit segmentation.

How to cite: Winsemius, H., Annor, F., Hagenaars, R., Luxemburg, W., Van den Munckhoff, G., Heeskens, P., Dominic, J., Waniha, P., Mahamudu, Y., Abdallah, H., Verver, G., and Van de Giesen, N.: OpenRiverCam, open-source operational discharge monitoring with low-cost cameras, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5880,, 2021.

EGU21-14276 | vPICO presentations | HS1.1.2 | Highlight

Hydromorphological monitoring of individual river reaches with UAV-data – image-based measurement of bathymetry and flow velocity

Anette Eltner, László Bertalan, and Eliisa Lotsari

Unmanned Aerial Vehicles (UAV) have become a commonly used measurement tool in geomorphology due to their affordable cost, flexibility, and ease of use. They are regularly used in fluvial geomorphology, among other fields, because the high spatiotemporal resolution of UAV data makes it possible to assess the continuum rather than relying on single samples.

In this study, UAV data are used to hydro-morphologically describe three different river reaches of lengths between 150 and 1000 m. Specifically, the surface flow velocity and bathymetry of the rivers were reconstructed. The flow velocities were calculated using the Particle Tracking Velocimetry (PTV) method applied to UAV video sequences. In addition, UAV-based imagery was acquired to perform 3D reconstruction above and below the water surface using SfM (Structure from Motion) photogrammetry, taking into account refraction effects as well as frame processing to increase the visibility of underwater features. Reference data for flow velocities were generated at selected positions using current meters as well as ADCP (Acoustic Doppler Current Profiler) readings. The image-based calculated bathymetry was compared with RTK-GNSS sampling depth measurements and also ADCP data.

The developed workflow enables rapid and regular measurement of hydrological and morphological data of river channels. This ultimately enables multi-temporal assessment and significantly improves hydro-morphodynamic modelling, in particular their calibration.

How to cite: Eltner, A., Bertalan, L., and Lotsari, E.: Hydromorphological monitoring of individual river reaches with UAV-data – image-based measurement of bathymetry and flow velocity, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14276,, 2021.

HS1.1.5 – Experimental hydrology and hydraulics in Geosciences

During the last decades, more and more researchers have concentrated their work on the study of overland flow and associated transport processes: new developments, innovative techniques and breakthroughs are being presented year after year, which is noteworthy. Whilst experimental hydrology has played an important role in many of these studies, it is not always acknowledged the main difficulties, limitations, challenges, but also advantages and opportunities in this study approach.


Bearing on personal involvement in three decades of experimental work in surface hydrology that contributed to improve our understanding of several hydrological processes (e.g. overland flow, sediment transport, rill and interrill erosion, infiltration), this presentation addresses shortly main issues related to the experimental part of that work, conducted in two continents. The work used experimental setups that focused mainly in the study of rainfall-runoff, overland flow and associated transport processes, namely water erosion. Experiments were conducted in natural, agricultural and urban surfaces, both in disturbed and undisturbed conditions or samples. Special attention has been given to mulching, wind-driven rain, and on the use of thermal tracers. The input in field-based studies was natural rainfall, whereas simulated rainfall simulators and/or run-on have been applied within laboratory-based experiments. In fact, the adaptability of rainfall simulators to different temporal and spatial scales allowed many experimental designs to suit specific research objectives.


This presentation highlights the inherent problems and difficulties in conducting studies to encompass such diverse situations as observed in natural and human-modified surfaces. However, the main objective is to stimulate the discussion and enhance understanding of the requirements of experimental research, both in the laboratory and in the field, since that can contribute to achieve further clarifications in surface hydrology. For example, runoff responses of urban, rural and periurban areas are still not well understood. Experimental research is also essential in multidisciplinary approaches aiming at further improving our knowledge on transports associated with runoff (e.g. litter, virus, microbial contaminants, emerging chemicals found in pharmaceuticals, personal care products, pesticides, industrial and household products, surfactants, metals).

How to cite: de Lima, J. L. M. P.: How useful is experimental hydrology in understanding overland flow and associated transport processes?, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12934,, 2021.

EGU21-3985 | vPICO presentations | HS1.1.5

Measurement of soil hydraulic properties of structured and repacked soils

Urša Pečan, Luka Žvokelj, Jure Ferlin, Vesna Zupanc, and Marina Pintar

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,, 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 (Ks) 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 Ks values. The Ks 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 Ks by the two devices. The results showed that the two devices produced varying Ks 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,, 2021.

EGU21-8389 | vPICO presentations | HS1.1.5

On the effect of different moss species on soil erosion, percolation and carbon relocation

Corinna Gall, Lena Grabherr, Martin Nebel, Thomas Scholten, Sonja M. Thielen, and Steffen Seitz

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,, 2021.

EGU21-9177 | vPICO presentations | HS1.1.5

Evaluating stream CO2 outgassing via Drifting and Anchored flux chambers in a controlled flume experiment

Filippo Vingiani, Nicola Durighetto, Marcus Klaus, Jakob Schelker, Thierry Labasque, and Gianluca Botter

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,, 2021.

EGU21-14426 | vPICO presentations | HS1.1.5

Hydraulic roughness estimation in vegetated floodplains

Lisdey Veronica Herrera Gomez, Giovanni Ravazzani, Michele Ferri, and Marco Mancini

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,, 2021.

EGU21-5400 | vPICO presentations | HS1.1.5

A physical model demonstrating critical zone structure and flow processes in headwaters

Xuhui Shen, Jintao Liu, Wanjie Wang, Xiaole Han, Jie Zhang, and Guofang Li

Equipped with complex terrain structure, physical models provide an alternative way in understanding and modeling how critical zone shapes hydrologic processes in headwaters for research and education in hydrology. However, this type of physical models is limited by frustrating rain-erosion or gully-erosion. Herein, in order to replace the real-world backfilling soil, we drew on the experience of normal concrete workmanship and adjusted the raw material’s proportion for three times. And it is found that saturated hydraulic conductivity (SHC) and field moisture capacity (FMC) are both well correlated with bulk density (BD) for the developed materials in three cases. Thereby, based on the strongest correlation (R2=0.75) between SHC and BD, two-layer alternative soil has been designed through altering BD in the physical model with complex terrain. The SHC values of alternative soil are close to that of the natural soil while the FMC values are far lower. Additionally, the non-uniform scaling of bedrock terrain was applied for the convenience of teaching and construction by zooming out a steep 0.31-ha zero-order basin 130 times horizontally and 30 times vertically. And multiple observation items, including free water level, temperature and humidity of soil, as well as outflow could provide potential opportunity to explore the role of single or combined critical zone’s element in modulating streamflow. We’d like to share this effective tool to facilitate the development of critical zone science and enrich experimental teaching methods.

How to cite: Shen, X., Liu, J., Wang, W., Han, X., Zhang, J., and Li, G.: A physical model demonstrating critical zone structure and flow processes in headwaters, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5400,, 2021.

EGU21-13721 | vPICO presentations | HS1.1.5

Using computer vision to monitor varying water levels: an exploratory laboratory experience

Jorge Isidoro, Ricardo Martins, and João de Lima

Monitoring water levels is fundamental in a variety of fields within geosciences, hydraulics, and hydrology. Examples of this can be found in the field in rivers, reservoirs, or surface runoff while, at a much lower scale, in the laboratory, e.g., open channel flow. This is an area of ​​great complexity, due to the large diversity of spatial and temporal scales of hydraulic systems and phenomena such as the non-linearity of fluid mechanics, sediment or pollutant transport, turbulence, the interactions between water and solid surfaces (natural or artificial), or atmospheric boundary conditions. The last decade has brought important advances in techniques associated with the acquisition and analysis of images, techniques encompassed in what is currently called “computer vision”.

In this work, a methodology based on image treatment and segmentation techniques was developed, which allows the detection of the free flow water surface over time in laboratory conditions using simple video equipment.

The objective of this work was to develop and validate an algorithm for detecting the free water surface with high temporal resolution. Other specific objectives were: (i) to validate the algorithm against measurements in a steady-state flow; (ii) to test the algorithm for accentuated oscillations of the free surface resulting from different bed geometries, slope, and discharge; and (iii) to assert the feasibility of the systematic use of non-specialized and inexpensive video equipment as a level measuring device, without compromising its accuracy.

All laboratory work took place at the Laboratory of Hydraulics, Water Resources and Environment of the Department of Civil Engineering of the Faculty of Sciences and Technology of the University of Coimbra. The channel has dimensions of 4.00m × 0.15m (L×W) and the slope is adjustable. Water is supplied to the channel, in a closed circuit, from a reservoir by means of a pump and piping system, and the flow controlled by a ball valve. The algorithm developed for detecting the free surface is based on the acquisition, treatment, analysis, and segmentation of images. MATLAB® was used to code functions to recognize the edges present in an image by the image intensity gradient as well as the best-defined segment present in the image, which, in this case, corresponds to the free water surface.

How to cite: Isidoro, J., Martins, R., and de Lima, J.: Using computer vision to monitor varying water levels: an exploratory laboratory experience, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13721,, 2021.

EGU21-14170 | vPICO presentations | HS1.1.5

Soil water dynamics in forested and irrigated sites in Cyprus 

Marinos Eliades, Adriana Bruggeman, Hakan Djuma, Melpomeni Siakou, Panagiota Venetsanou, Christos Zoumides, and Christof Huebner

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,, 2021.

EGU21-2616 | vPICO presentations | HS1.1.5

Water flow mechanisms and unproductive water losses in rice-based cropping systems in the humid tropics

Amani Mahindawansha, Philipp Kraft, Christoph Külls, and Lutz Breuer

In rice production areas in the world, increasing water scarcity is a major problem. Among the water saving techniques, integrating water saving non-flooded crops into the flooded rice system during the dry season is one of the promising water-saving approaches. Therefore, there is a necessity to improve the understanding of the water flow dynamics and losses in crop rotational systems under different climatic conditions in irrigated agricultural fields. That understanding can be used to lower the water requirements to build more efficient water management systems. We experimentally investigated the water flow processes and water losses by introducing non-flooded crops during the dry season (dry rice and maize) followed by flooded rice in the wet season and compared this to flooded rice in both seasons. We measured stable isotopes of water (δ2H and δ18O) in extracted soil water and liquid samples (Groundwater, ponded surface water, rainwater, and irrigation water). The Craig–Gordon equation was applied to estimate the fraction of evaporation losses. Results reveal that the soil isotopic profile patterns reflect the soil water transport processes and differ depending on the irrigation frequencies and crop diversification. Matrix flow and slow soil water infiltration, soil evaporation, and preferential flow via desiccation cracks were identified as the main water flow mechanisms in the irrigated fields. During the dry season, the evaporation effect on soil water is higher and water losses decreased from the beginning towards the end of the seasons. However, greater unproductive water losses were estimated during the wet season compared to the dry season. Finally, the results suggested that introducing dry seasonal crops to the crop rotation system for reducing the unproductive water losses is a good alternative method.


How to cite: Mahindawansha, A., Kraft, P., Külls, C., and Breuer, L.: Water flow mechanisms and unproductive water losses in rice-based cropping systems in the humid tropics, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2616,, 2021.

Water temperature, a crucial environmental factor, has a direct impact on almost all ecological and biogeochemical processes. The hydrological and thermal regimes in the Yangtze River have changed greatly due to the constructions of the Three Gorges Reservoir (TGR). To quantify the impact of TGR on the water temperature regime, we present a regression-modeling framework to reconstruct the temporal pattern of flow and temperature variation along the middle reach of the river in the absence of the TGR. By comparing reconstructed water temperatures to observed water temperature for the post-impounded period, the influence of impoundment on water temperature was estimated. Results show that TGR has had a greater impact on water temperature than natural changes in air temperature and discharge. The reservoir acts as a source of cold water in spring, summer and autumn and a warm source in winter. The results of this study illustrate the pronounced effect of the TGR on the temperature regime of the Yangtze River. We hope this study could provide a scientific reference for ecological operation of TGR facing biological conservation.

Note: This study has been published in Journal of Hydrology (Tao, Y., Wang, Y., Rhoads, B., Wang, D., Ni, L. and Wu, J., 2020. Quantifying the impacts of the Three Gorges Reservoir on water temperature in the middle reach of the Yangtze River. Journal of Hydrology. 582.).

How to cite: Tao, Y., Wang, Y., and Wang, D.: Analysis on impacts of the Three Gorges Reservoir on water temperature in the middle reach of the Yangtze River, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3613,, 2021.

EGU21-8526 | vPICO presentations | HS1.1.5

Analysis of the active length dynamics on intermittent streams using water presence sensors

Francesca Zanetti, Nicola Durighetto, Filippo Vingiani, and Gianluca Botter

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,, 2021.

EGU21-9061 | vPICO presentations | HS1.1.5

Groundwater recharge estimates combining soil isotope profiles and classical soil water monitoring techniques

Nina Krüger, Christoph Külls, and Marcel Kock

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,, 2021.

EGU21-4751 | vPICO presentations | HS1.1.5 | Highlight

Combining static and portable Cosmic Ray Neutron Sensor (CRNS) data to assess catchment scale heterogeneity in soil water content and implications for runoff generation

Katya Dimitrova Petrova, Rafael Rosolem, Chris Soulsby, Mark Wilkinson, Allan Lilly, and Josie Geris

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,, 2021.

EGU21-9210 | vPICO presentations | HS1.1.5

The Isotopic Composition of Cyprus Precipitation. A Tool of Isotope Hydrology.

Christos Christofi, Adriana Bruggeman, and Christoph Kuells

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,, 2021.

EGU21-13338 | vPICO presentations | HS1.1.5 | Highlight

Innovative real-time sensing of flow dynamics in groundwater and sediments to map contaminant spreading

Goedele Verreydt, Niels Van Putte, Timothy De Kleyn, Joris Cool, and Bino Maiheu

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,, 2021.

EGU21-14566 | vPICO presentations | HS1.1.5

A daily water balance model with a dynamic wetted area for estimating drainage from soil moisture observations in an irrigated orchard

Adriana Bruggeman, Melpo Siakou, Marinos Eliades, Hakan Djuma, and Christos Zoumides

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,, 2021.

HS1.2.1 – Role of hydrology in policy, society and interdisciplinary collaborations: across disciplines and beyond scientists

EGU21-227 | vPICO presentations | HS1.2.1 | Highlight

The construction of reference conditions under the EU Water Framework Directive

Tobias Krueger and James Linton

With this contribution we connect to the 3rd theme of the session, ‘hydrology as practiced within society’. Based on our recent article Linton & Krueger (2020), we demonstrate how the reference conditions and subsequent water quality targets under the EU Water Framework Directive (WFD) do not exist ‘out there’, waiting to be discovered, but are outcomes of complex negotiations between hydrological, ecological, technical and socio-political realities.

Treating reference conditions and targets as naturally given, as WFD implementation does at least implicitly, upholds a false sense of authority that obscures the manifold choices in the creation of the reference conditions while denying the people charged with implementing the targets or having to live with the resulting water quality an influence over those choices.

We argue that the concept of reference conditions must be abandoned in a world were water everywhere bears the traces of human presence. Instead, water quality targets should be set openly, location-specific and involving those for whom water quality is a matter of concern. We will give examples from other jurisdictions where such an approach is established practice.


Linton, J. and Krueger, T. (2020), The Ontological Fallacy of the Water Framework Directive: Implications and Alternatives. Water Alternatives, 13(3): 513-533.

How to cite: Krueger, T. and Linton, J.: The construction of reference conditions under the EU Water Framework Directive, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-227,, 2021.

EGU21-8778 | vPICO presentations | HS1.2.1 | Highlight

Structuring the water quality policy problem: Applying Q-methodology to explore perspectives in hydrology, government, and community

Schuyler Houser, Reza Pramana, and Maurits Ertsen

Recognizing the interrelatedness of water management and conceptual value of IWRM, many water resource governance systems are shifting from hierarchical arrangements towards more collaborative and participative networks. Increasing calls for participation recognize the value of drawing on social, political-administrative, and other kinds of knowledge in addition to technical water expertise. Participatory mandates, coordination bodies, and science-policy networks have emerged to facilitate knowledge integration, promote adaptive capacity, and align organizations in poly-centric systems.

Since the maintenance and effectiveness of such arrangements are contingent on trust and alignment rather than command and control, and since diverse stakeholders are engaged to co-produce knowledge, collaborators must grapple with identifying shared goals, developing knowledge management strategies to organize inputs, and attaining early progress to promote ongoing cooperation. But guidance is limited with respect to how such integrative aims are to be accomplished.

This research explores how systematic (but not necessarily convergent) problem structuring can support the forming, reordering, and cohering of water resource networks, especially when a complex issue – in this case, water quality management – rises to prominence on the policy agenda. In the early stages of a water quality project in the Brantas River Basin, Indonesia, stakeholder discussions suggested divergent conceptualizations of water quality and ideas about what conditions ‘matter’. Thus, instead of taking hydrological data as the starting point, this research first asks: What Brantas River(s) are we talking about, and why? Q-methodology is used to identify alternative perspectives on water quality held by a diverse set of stakeholders, including hydrologists. The analysis explores which aspects of the policy problem are consistent, which are contested, and whether problems indicated by hydrological science overlap, conflict, or cohere with those perceived by other stakeholders.

The research posits that, if scientists, engineers, decision-makers, community leaders, and other participants can appreciate areas of convergence and divergence regarding the water quality problem itself, they can lay groundwork for knowledge co-production; recognize opportunities for cooperation; better locate science in the problem space; and identify potential early wins to secure commitment. The research also asks to what extent consensus in problem structuring is necessary, or whether it is sufficient to identify strategies that are acceptable to different ontological viewpoints.

How to cite: Houser, S., Pramana, R., and Ertsen, M.: Structuring the water quality policy problem: Applying Q-methodology to explore perspectives in hydrology, government, and community, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8778,, 2021.

Since 2018, the “European Union Water Initiative Plus for Eastern Partnership (EaP) Countries (EUWI+)” has been providing significant assistance in the development of a number of pilot projects focused on the phased implementation of the main provisions of the EU Water Framework Directive (WFD) related to groundwater monitoring in the Republic of Belarus. The implementation began with the identification (delineation) of groundwater bodies, their characterization, assessment and improvement of groundwater monitoring networks and several groundwater investigations in order to collect the necessary data to assess groundwater risk and status. Just recently, transboundary cooperation with Ukraine, resulted in the identification of common transboundary groundwater corridors and the proposal of a monitoring network for transboundary groundwater.

The next logical step in the implementation of the WFD is the assessment of the quantitative and qualitative groundwater status, which confirms whether the environmental objectives of the WFD for groundwater have been achieved. Thus, in 2020, a draft methodology for assessing the groundwater status in the Republic of Belarus in accordance with the principles of the WFD was developed.

The elaborated draft methodology defines criteria for the assessment of groundwater quantitative and qualitative status (“good” and “poor”) and the assessment of the risk (“at risk” and “not at risk”) whether the environmental objectives of the WFD cannot be achieved. The criteria consider all relevant and related national legislation and legal provisions which are in force and the assessments follow step-by-step implementation procedures.

A preliminary testing of the proposed methodology and a list of open issues that need to be solved complete the work.

The proposed methodological approach is a first attempt and needs to be thoroughly tested with available groundwater monitoring data in the coming months, both for groundwater bodies with dense monitoring networks and groundwater bodies with limited groundwater monitoring, Finally, the approach needs to be intensively discussed at national level before being implemented into national legislation.

How to cite: Vasniova, O., Biarozka, O., Scheidleder, A., and Humer, F.: Proposed methodology for the assessment of groundwater chemical and quantitative status in the Republic of Belarus (in accordance with the principles of the EU Water Framework Directive), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4102,, 2021.

EGU21-11041 | vPICO presentations | HS1.2.1 | Highlight

Is scientific research on water-tourism nexus responding to the challenges identified by stakeholders and policy-makers? The case of Benidorm, Spain

Rubén A. Villar-Navascués, Sandra Ricart, Antonio M. Rico-Amorós, and María Hernández-Hernández

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,, 2021.

EGU21-13592 | vPICO presentations | HS1.2.1

The transition toward resilient water management regimes: where are we now?

Matteo Mannocchi

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,, 2021.

EGU21-599 | vPICO presentations | HS1.2.1

The HydroSocial Cycle approach to deepen on socio-ecological systems analysis and water management

Sandra Ricart and Andrea Castelletti

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,, 2021.

Knowledge has been shown to be more effectively implemented in practice when produced in collaboration between researchers and other stakeholders as the co-produced knowledge is more likely to be accepted and found relevant. Knowledge co-production processes have however been found guilty of depoliticizing and hiding political struggles to the end of reinforcing existing unequal power relations and prevent broad societal transformation from taking place. From this perspective, knowledge co-production can come into conflict with participatory governance that focuses on the empowerment and capacity building of actors, social justice and advocacy. In this presentation I take a closer look at this conflictual perspective and propose a research focus on knowledge practices for exploring and analyzing participatory governance options for flood risk management (FRM) and disaster risk reduction (DRR). I do this by exemplifying and presenting a research design developed within the newly started PARADeS-project.

The PARADeS-project is a research project led by German research institutions in close collaboration with partners in Ghana and with the overall aim to contribute to enhancing Ghana’s national flood risk and disaster management strategy. Co-production of knowledge is foreseen to take place in several workshops including collaborative modelling, scenario- and policy back-casting exercises. One of the planned project outputs is a concept of participatory governance in FRM and DRR based on the findings from a stakeholder analysis, a policy network analysis and a participatory assessment of different policy options.

In this project context a research focus on stakeholders’ knowledge practices can be used to inform and improve the participatory governance concept and facilitate its implementation process. Knowledge is used by stakeholders as a powerful resource in suggesting certain policy options and convincing others of their necessity. Knowledge practices entail how actors use knowledge to argue, convince and make decisions. Through knowledge practices, stakeholders decide what knowledge to base decisions on and how to convince others of their position using that knowledge. What knowledge becomes accepted as legitimate in such interactions - often deliberative settings - can be decisive for the acceptability of any policy option. It is therefore important to study not only the different types of stakeholders and technical options for FRM and DRR, but the interaction between stakeholders and how they use information and co-create knowledge - the knowledge practices.

Within the presentation I discuss the proposed research design for how to study knowledge practices and how to make use of these findings when going from research project and co-production of knowledge to a concept of participatory governance in flood risk management and disaster risk reduction in Ghana.

How to cite: Wallin, I.: From co-production of knowledge to a participatory governance concept: a research design focusing on knowledge practices in flood risk management and disaster risk reduction, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15643,, 2021.

EGU21-10819 | vPICO presentations | HS1.2.1

Stakeholder Participation in Flood-Related Disaster Risk Management in Ghana

Fafali Roy Ziga-Abortta, Sylvia Kruse, Britta Höllermann, and Joshua Ntajal

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,, 2021.

EGU21-3136 | vPICO presentations | HS1.2.1

Systematic User Feedback to Co-develop a Flood Early Warning System in West Africa

Martijn Kuller, Jafet Andersson, and Judit Lienert


The Horizon 2020 project FANFAR ( 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.


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.


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.

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:
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,, 2021.

EGU21-13276 | vPICO presentations | HS1.2.1

Transdisciplinary Design of Adaptation Pathways in Peri-urban India: Planning for Water Needs in a Sustainable Urban Transition 

Sharlene L. Gomes, Sarah Luft, Shreya Chakraborty, Leon M. Hermans, and Carsten Butsch

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,, 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,, 2021.

EGU21-7288 | vPICO presentations | HS1.2.1

Hydrology across disciplines: the experience of a Public Hydrological Service in Italy

Giuseppe Ricciardi, Alessandro Allodi, Fabio Bordini, Monica Branchi, Francesco Cogliandro, Elisa Comune, Valentina dell'Aquila, Mauro Del Longo, Giuseppe Nicolosi, Mauro Noberini, Filippo Pizzera, Fabrizio Tonelli, and Franca Tugnoli

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,, 2021.

EGU21-5609 | vPICO presentations | HS1.2.1

How are guaranties of quality forged and assessed in flood risk modelling ?

Remi Barbier and Isabelle Charpentier

Models and simulations have become essential elements of water management in catchments (Chong, 2019). This raises the question of confidence in the models. We are interested in the criteria used to judge their quality and the way in which the uncertainties inherent to modelling are taken into account and explained throughout the process. 

Our communication is based on the results of one interdisciplinary research project on modelling developed in the framework of Flood Risk Prevention Plans (FRPP). In a nutshell, FRPPs are regulatory documents elaborated under the responsibility of the State. They are then imposed to local urban planning regulations. Their elaboration is based on the modelling of the flood hazard.

We formulate the problem of trust from the perspective of the State services. The latter entrust consulting firms with the implementation of hazard modeling, which (generally) benefit from a strong asymmetry of skills in their favour. Based on a survey conducted in several government departments, we analyze the practice of ordering, piloting and validating these models. The question posed is the following: "how are guaranties of quality and suitability forged and assessed in flood risk modelling?" We review the different stages of the process, from the writting of the specifications to the final validation of the results, including the multiple interactions throughout the work.  



How to cite: Barbier, R. and Charpentier, I.: How are guaranties of quality forged and assessed in flood risk modelling ?, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5609,, 2021.