Operational forecasting and warning systems for natural hazards: challenges and innovations

This interactive session aims to bridge the gap between science and practice in operational forecasting for different water-related natural hazards. Operational (early) warning systems are the result of progress and innovations in the science of forecasting. New opportunities have risen in physically based modelling, coupling meteorological and hydrological forecasts, ensemble forecasting, impact-based forecasting and real time control. Often, the sharing of knowledge and experience about developments are limited to the particular field (e.g. flood forecasting or landslide warnings) for which the operational system is used.
The focus of this session will be on bringing the expertise from different fields together as well as exploring differences, similarities, problems and solutions between forecasting systems for varying natural hazards. Real-world case studies of system implementations - configured at local, regional and national scales - will be presented, including trans-boundary issues. An operational warning system can include, for example, monitoring of data, analysing data, making forecasts, giving warning signals and suggesting response measures.
Contributions are welcome from both scientists and practitioners who are involved in developing operational forecasting and/or management systems for water-related natural or man-made hazards, such as flood, drought, tsunami, landslide, hurricane, hydropower, pollution etc.

Co-organized by NH9
Convener: Céline Cattoën-Gilbert | Co-conveners: Michael Cranston, Femke Davids, Ilias Pechlivanidis
vPICO presentations
| Thu, 29 Apr, 09:00–10:30 (CEST)

vPICO presentations: Thu, 29 Apr

Chairpersons: Céline Cattoën-Gilbert, Michael Cranston, Ilias Pechlivanidis
Arianna Onate-Paladines, Bart van Osnabrugge, Jan Verkade, and Albrecht Weerts

Hydrological forecasting systems represent an important decision-making tool for water and risk management. In this context, there is increasing development and implementation of such systems worldwide, which are commonly tailor-made: designed and configured according to the information and hydrological models available for a specific location and/or extent to answer to precise needs. Therefore, the concepts of setup automation and replicability of configuration of such systems are often overlooked, especially when they follow a model-centric approach.

However, in a global forecasting context such as the one adopted by Deltares’ GLOFFIS (den Toom et al. 2020), the automation of hydrological forecasting systems’ set up becomes an essential part for the development, as it enables the fast forward and constant addition of local specialized models where available in the system on a global extent, as well as by using local regional weather forecasts, reanalysis models or satellite data as forcing to produce estimates of various hydrological parameters, instead of focusing on a single model or NWP source.

In that sense, a prototype of a configuration production system for GLOFFIS was developed, which comprises two main components: (1) an external relational database holding the information regarding the set of hydrological models to be incorporated and weather data products used and, (2) a set of python scripts, that query the database and generate the configuration XML files needed for the system (as GLOFFIS is based on Delft-FEWS) to accomplish an automated deployment.

This new approach for system’s configuration boosts the potential related to system maintenance, expansion, and replicability, which could be beneficial not only when developing large hydrological forecasting systems, but also for local systems developed using Delft-FEWS, as well as to encourage the distribution of forecasting systems worldwide.



den Toom, M., Verkade, J., Weerts, A., and Schotmeijer, G.-J.: Development of the Deltares global fluvial flood forecast system, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-22344, https://doi.org/10.5194/egusphere-egu2020-22344, 2020.

How to cite: Onate-Paladines, A., van Osnabrugge, B., Verkade, J., and Weerts, A.: Deployment automation of hydrological forecasting systems on a global scale., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3011, https://doi.org/10.5194/egusphere-egu21-3011, 2021.

Georgios Boumis, Bart van Osnabrugge, and Jan Verkade

Operational near real-time flood forecasting relies heavily on adequate spatial interpolation of precipitation forcing which bears a huge impact on the accuracy of hydrologic forecasts. In this study, the generalized REGNIE (genRE) interpolation technique is examined. The genRE approach was shown to enhance the traditional Inverse Distance Weighting (IDW) method with information from existing observed climatological precipitation data sets (Van Osnabrugge, 2017). The successful application of the genRE method with a re-analysis precipitation data set, expands the applicability of the method as detailed re-analysis data sets become more prevalent while high density observation networks remain scarce.

Here, the approach is extended to use climatological precipitation data from the Met Éireann’s Re-Analysis (MÉRA). Investigations are carried out using hourly precipitation accumulations for two major flood events induced by Atlantic storms in the Suir River Basin, Ireland. Alongside genRE, the following techniques are comparatively explored: Inverse Distance Weighting (IDW), Ordinary Kriging (OK) and Regression Kriging (RK). Cross-validation is applied in order to compare the different interpolation methods, while spatial maps and correlation coefficients are utilized for assessing the skill of the interpolators to emulate the climatology of MÉRA. In the process, a preliminary intercomparison between the observed precipitation and MÉRA precipitation for the two events is also made.

In a statistical sense, cross-validation results verify that genRE performs slightly better than all three interpolation techniques for both events studied. Overall, OK is found to be the most inadequate approach, specifically in terms of preserving the original variance in observed precipitation. MÉRA manages to reproduce the temporal variations of observations in a good manner for both events, whereas it displays less skill when considering spatial variations especially where topography has a major influence. Finally, genRE outperforms all other interpolators in mimicking the climatological conditions of MÉRA for both events.


Van Osnabrugge, B., Weerts, A.H. and Uijlenhoet, R., 2017. genRE: A method to extend gridded precipitation climatology data sets in near real-time for hydrological forecasting purposes. Water Resources Research, 53(11), pp.9284-9303.

How to cite: Boumis, G., van Osnabrugge, B., and Verkade, J.: Application of the "genRE" approach to spatial interpolation of precipitation gauge data for the Suir River Basin, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-520, https://doi.org/10.5194/egusphere-egu21-520, 2021.

Alexia Tsouni, Haris Kontoes, Themistocles Herekakis, Stavroula Sigourou, and Theodora Perrou

Flood has become the most frequent and deadliest type of disaster by far, responsible for the 43.5% of deaths in 2019. What is more, the number of flood events has extremely increased during the last decade (2000-2019), compared to the previous one (1980-1999) (CRED 2020). Therefore, policy and decision makers, more than ever, need efficient flood monitoring tools in order to facilitate their work towards increasing disaster resilience, especially in the urban and peri-urban areas, where most of the population and critical infrastructure are located. For this purpose, the FloodHub system has been developed by the Center of Earth Observation and Satellite Remote Sensing BEYOND, at the National Observatory of Athens, in the framework of the EuroGEO Disaster Resilience Action Group, supported by on-going actions (SMURBS / ERA-PLANET and Excelsior H2020 projects and the sponsor Hellenic Petroleum S.A.). The innovation of the system lies in the integration of different data sources, so as to deliver a reliable flood early warning system, and an operational awareness picture of the crisis every 5’ to the relevant authorities, namely on three levels: municipality, region, and national civil protection. FloodHub allows the near-real-time ingestion and assimilation of hydrometeorological measurements from in-situ telemetric stations, Sentinels data, and crowdsourced data, in a multi-source data fusion concept, using sophisticated hydrologic and hydraulic modelling and statistical regression techniques. It offers increased reliability through a continuous validation and optimization of results, automation in assimilating flood modeling in real time, computational efficiency, openness, flexibility, scalability, transferability, and the speed to meet rapid awareness during the crisis. Therefore, FloodHub is a useful tool in the hands of the relevant authorities and key stakeholders, contributing to an effective flood risk and crisis management. This is in line with the requirements for the implementation of the EU Floods Directive 2007/60/EC, the Sendai Framework for Disaster Risk Reduction, the UN SDGs, as well as the GEO’s Societal Benefit Areas.

How to cite: Tsouni, A., Kontoes, H., Herekakis, T., Sigourou, S., and Perrou, T.: The innovation of the FloodHub system for a reliable flood early warning and crisis management, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8894, https://doi.org/10.5194/egusphere-egu21-8894, 2021.

Eoin Burke

The Berkel catchment in the east of the Netherlands and western Germany is an area with a long history of river flooding. Flooding in the area is caused by a combination of fast responding hydrological characteristics in the upper catchment and impermeable glacial till in the shallow sub-surface. In the past, flood mitigation in the Berkel catchment involved straightening river channels, minimising vegetation growth in the watercourse and an extensive weir network to control water flow. The changing climate and an integral approach to water management demand a modern, robust approach to mitigating flood damage in the Berkel catchment. As a result, an operational flood forecasting system (Delft-FEWS) which utilises recently developed hydrologic rainfall-runoff models and state of the art data assimilation (DA) methods has been developed. This system generates 7-day discharge forecasts at hourly intervals using meteorologic forecast and local discharge observations.

The lowland rainfall-runoff model, WALRUS (Brauer et al., 2014) is implemented to generate discharge forecasts. The WALRUS model set-up has been designed and calibrated in a semi-distributed layout to ensure the spatial and temporal elements of discharge peaks are captured. Importantly, this flood forecasting system has adopted recent advancements in DA to strengthen the accuracy of flood forecasts. Specifically, the DA method used in this system follows the work by Sun et al. (2020). The DA allows the model to be updated using field observations at 5 locations in the catchment, available in near real-time. Reforecasting illustrates the advantages of using rainfall-runoff models that capture the specific hydrologic characteristics of a catchment as well as the benefit of using advanced DA methods in flood forecasting.



Brauer, C. C., Teuling, A. J., Torfs, P. J. J. F., & Uijlenhoet, R. (2014). The Wageningen Lowland Runoff Simulator (WALRUS): a lumped rainfall–runoff model for catchments with shallow groundwater. Geoscientific model development, 7(5).

Sun, Y., Bao, W., Valk, K., Brauer, C. C., Sumihar, J., & Weerts, A. H. (2020). Improving forecast skill of lowland hydrological models using ensemble Kalman filter and unscented Kalman filter. Water Resources Research, 56(8), e2020WR027468.

How to cite: Burke, E.: Applying ensemble Kalman Filtering to improve operational flood forecasting for the Berkel catchment (Eastern Netherlands), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10549, https://doi.org/10.5194/egusphere-egu21-10549, 2021.

Adhithiyan Neduncheran, Annalina Lombardi, Barbara Tomassetti, Marco Verdecchia, and Valentina Colaiuda

An extreme weather event hit the coastal city of Chennai, India, in November-December 2015 causing severe damage to infrastructure worth billions of dollars, people’s lives and their livelihood. Nearby districts to Chennai, such as Cuddalore, Kancheepuram and Tiruvallur were also affected by rainfall over 300mm during the first week of December. This was caused by the unusual wind surges in the troposphere providing favorable environmental conditions for the extensive rainfall and the formation of a deep depression in the Bay of Bengal on 30 November 2015, which was blocked by Eastern Ghats that inhibited the movement of the synoptic system. Electricity and telecommunication lines were suspended and some hospitals were shut down for a few days. It brought the whole city into a state of emergency and National Disaster Rescue Force were deployed in an effort to take care of the evacuation of people.

In this work, we present the estimation of the hydrological stress caused by the extreme rainfall event in Chennai and the nearby river basins during the course of this northeastern monsoon event in India. The hydrological stress is given through the application of Best Discharge based Drainage (BDD)  Index, calculated by the CETEMPS Hydrological Model (CHyM). Hydrological simulation is carried out by forcing the model with the 3-hourly NASA IMERG 0.1x0.1 grid precipitation dataset. Preliminary results show a spatial coherence between the hydrological stress detected by the index and the most impacted river segments, due to heavy precipitation. The application of hydrological stress indices is helpful for forecasting fluvial floods in the river network with minimum calibration requirements, providing a useful tool for warning the respective authorities for minimal losses due to natural calamities.

How to cite: Neduncheran, A., Lombardi, A., Tomassetti, B., Verdecchia, M., and Colaiuda, V.: The Chennai flood (India): preliminary results using CETEMPS Hydrological Model (CHyM) stress index, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9786, https://doi.org/10.5194/egusphere-egu21-9786, 2021.

Martijn Kwant, Frederique de Groen, Margreet van Marle, Arjen Haag, and Herman Haaksma

Traditional flood risk studies often focus on direct economic impact, such as property damage or agricultural loss. However, the impact of floods is not limited to these direct damages. In fact societal costs and/or cascading effects are often much higher than the direct impact of floods. Cascading effects, such as access to healthcare and infrastructure accessibility are vital components for efficient emergency response management. This requires methodologies to quickly analyze the impact of large-scale floods on infrastructure networks.


In this case study, the use of satellite-based flood maps are examined in combination with network criticality in the Mandalay region in central Myanmar. This region was severely affected by flooding after heavy monsoon rains in 2019. Many regions in the world are affected by this type of floods every year, resulting in large scale evacuations and limited access to health care. During these type of events, the transportation network is a crucial part for emergency response, as it is used for the delivery of goods, evacuation and deployment of emergency hospitals.


The core of this study is a methodology to assess near real-time flood extents based on Sentinel-1 satellite imagery and the impact on network criticality. These tools were used to analyze the redundancy of the infrastructure network and quantify cascading impacts of flood hazards such as road accessibility and access to medical services. The methodology shows potential for operational use by linking with flood early warning systems (e.g. Delft-FEWS) enabling impact-based forecasting.

How to cite: Kwant, M., de Groen, F., van Marle, M., Haag, A., and Haaksma, H.: Near Real-Time Flood Impact Analysis on Road Networks, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16545, https://doi.org/10.5194/egusphere-egu21-16545, 2021.

Miguel Arestegui, Miluska Ordoñez, Abel Cisneros, Giorgio Madueño, Cinthia Almeida, Vannia Aliaga, Nelson Quispe, Carlos Millán, Waldo Lavado, Samuel Huaman, and Jeremy Phillips

Debris flow, locally known as huaycos, impact the east part of the metropolitan city of Lima, capital of Peru. However, after many extreme events such as the one related to the 2017 “Coastal Niño” or the one in 1987, there is a lack of historical data and sufficiently accurate monitoring systems.


The fact that this area is densely populated presents obvious challenges, from social and physical perspectives, but also some opportunities. We present our experience using open source & low cost rain gauges on previously unmonitored microwatershed, as part of a broader watershed-level monitoring system enhancement by SENAMHI (National Meteorological and Hydrological Service). We also present our experience on linking monitoring systems, debris flow modelling and community based risk management towards developing operational EWS.

How to cite: Arestegui, M., Ordoñez, M., Cisneros, A., Madueño, G., Almeida, C., Aliaga, V., Quispe, N., Millán, C., Lavado, W., Huaman, S., and Phillips, J.: Using open source & low cost rain gauges to support debris flow real-time monitoring in Lima, Peru, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16546, https://doi.org/10.5194/egusphere-egu21-16546, 2021.

Husain Najafi, Stephan Thober, Oldrich Rakovec, Pallav Kumar Shrestha, and Luis Samaniego-Eguiguren

Helmholtz Centres are developing a research infrastructure in Germany to investigate the interactions of short-term events and long-term trends across Earth compartments under the Modular Observation Solutions for Earth System initiate (MOSES- https://www.ufz.de/moses/). A near-real time hydroclimate forecasting system at sub-seasonal to seasonal time range (HS2S) is developed for MOSES to provide tailored information for early warning of extreme events. 

Here, we introduce two components of the HS2S which benefits from operational forecasts provided by the European Center for Medium-range Weather Forecast (ECMWF). The first component is weekly averaged forecasts of two atmospheric variables (total precipitation and maximum air temperature) which are bias corrected using a trend-preserving approach. The second component is German hydrological forecasting system. We use the mesoscale Hydrological Model (mHM- https://www.ufz.de/mhm) for generating hydrological initial conditions and ensemble forecasting. The same approach by German Drought Monitor (www.ufz.de/duerremonitor) is applied to interpolate near-real time in-situ observations from the German Meteorological Service (DWD) into 1-km grids. Then 51 real-time atmospheric daily ensemble forecasts from ECMWF ensemble extended product are bias corrected to generate of soil moisture and streamflow forecasts up to 30-day in advance. By post-processing mHM ensemble forecasts, an overview of drought conditions for the next 30-days horizon is disseminated online over Germany (https://www.ufz.de/moses/index.php?en=47304). Hydroclimate forecast are updated operationally twice a week to support MOSES event-driven campaigns for flood, drought and heat waves and to understand the predictability and skill of near-real time hydroclimate forecasts in Central Europe based on the state-of-the-art models and tools.  

How to cite: Najafi, H., Thober, S., Rakovec, O., Shrestha, P. K., and Samaniego-Eguiguren, L.: German Near-Real Time Ensemble Hydroclimate Forecasting System, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16397, https://doi.org/10.5194/egusphere-egu21-16397, 2021.

Angelos Alamanos, Alec Rolston, and Suzanne Linnane

During the summer of 2020, five bathing sites in Ireland were closed for the full season because of bad water quality, and 12 more received warnings and closed temporarily. Wastewater and sewage discharges, and Stormwater Overflows (SWOs) were the main causes. Although SWOs are not regarded as a management priority, they contributed to almost every bathing site’s closure, sharpening other existing issues. In this study, the precipitation in Ireland was analysed to inform a national stakeholder forum (An Fóram Uisce/The Water Forum), which provides guidance on water management to the national government, and the national water utility on the rainfall-driven SWOs issues. A correlation analysis of the observations of the closest meteorological stations of each bathing site is presented, showing that there are significant variances across the country, and each area (bathing site) must be examined separately. The Greater Dublin Area (GDA)’s precipitation was then further analysed because eight bathing sites in the GDA are facing SWO problems. Daily, monthly, and annual timeseries (10 years) were studied for peaks, trends, and seasonality. A daily forecast was performed for 1-year, using five techniques, starting from the simplest to the more complex: Seasonal naïve, Seasonal ARIMA, Holt-Winters Seasonal Exponential Smoothing, Non-seasonal ARIMA using seasonality as an exogenous covariate, and Christiano-Fitzgerald filtering. The peculiarities of the observed GDA’s precipitation timeseries are further highlighted through monthly, seasonal, and annual analyses. The trends showed that more extreme events (higher peaks) occurred over the last 30-20 years, thus, a brief extreme analysis was carried out using 120-year daily precipitation data. The Generalised Extreme Value (GEV) distribution was fitted to the historic precipitation using the L-moments method, and was compared to other theoretical distributions, commenting on their goodness of fit. Additionally, by comparing the historic data of temperature and rainfall from all the stations, with the respective reported projections of the future climate change scenarios, all stations we found to have already faced greater ranges than the predicted (e.g. the GDA has already experienced 45% higher temperature than forecast by the worst-case climate change predictions). Overall, the analysis indicates that water quality deterioration from SWOs caused by heavy rainfall events is forecast to become more frequent in the future. Consequently, managing authorities need to pay more attention to SWOs, instead of continuing to consider them as an occasional problem impacting water quality. This is the first study in the country approaching the issue of bathing water quality from the perspective of precipitation analysis. Very few similar rainfall analyses have been carried out in Ireland, thus this work has also a significant added value to the Irish climate literature.

How to cite: Alamanos, A., Rolston, A., and Linnane, S.: Irish bathing sites closures and Stormwater Overflows: Precipitation forecasts, extremes analysis, and comparison with climate change projections, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5350, https://doi.org/10.5194/egusphere-egu21-5350, 2021.

Yuan-Yuan (Annie) Chang, Konrad Bogner, Massimiliano Zappa, Daniela I.V. Domeisen, and Christian M. Grams

Across the globe, there has been an increasing interest in improving the predictability of weekly to monthly (sub-seasonal) hydro-meteorological forecasts as they play a valuable role in medium- to long-term planning in many sectors such as agriculture, navigation, hydro-power production, and hazard warnings. A Precipitation-Runoff-Evapotranspiration HRU model (PREVAH) has been previously set up with raw metrological forcing of 51 ensemble members and 32 days lead time taken from the operational European Centre for Medium-Range Weather Forecasts (ECMWF) extended-range forecast. The PREVAH model is used to generate hydrological forecasts for the study area, which consists of 300 catchments covering approximately the entire area of Switzerland. The primary goal of this study is to improve the quality of the categorical forecast of weekly mean total discharge in a catchment laying in the lower, normal, or upper tercile of the climatological distribution at a monthly horizon. Therefore, we explore the approach to post-process PREVAH outputs using machine learning algorithm Gaussian process. Weather regime (WR) data, based on 500 hPa geopotential height in the Atlantic-European region are used as an added feature to further enhance the post-processing performance.

By comparing the overall accuracy and the ranked probability skill score of the post-processed forecasts with the ones of raw forecasts we show that the proposed post-processing techniques are able to improve the forecast skill. The degree of improvement varies by catchment, lead time and variable. The benefit of the added WR data is not consistent across the study area but most promising in high altitude catchments with steep slopes. Among the seven types of WRs, the majority of the corrections are observed when either a European blocking or a Scandinavian blocking is forecasted as the dominant weather regime. By applying a “best practice” to each individual catchment, that is the processing technique with the highest accuracy among the different proposed techniques, a median accuracy of 0.65 (improved from a value of 0.53 with no processing technique) can be achieved at 4-week lead time. Due to the small data size, the conclusions should be considered preliminary, but this study highlights the potential of improving the skill of sub-seasonal hydro-meteorological forecasts utilizing weather regime data and machine learning in a real-time deployable setup.

How to cite: Chang, Y.-Y. (., Bogner, K., Zappa, M., Domeisen, D. I. V., and Grams, C. M.: Improving Sub-Seasonal Hydrological Forecasts in Switzerland: An Exploratory Study of Post-Processing Techniques by Using Machine Learning and Weather Regime Diagnostics, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2244, https://doi.org/10.5194/egusphere-egu21-2244, 2021.

Elisabeth Vogel, Julien Lerat, Robert Pipunic, Andrew J. Frost, Morwenna Griffiths, and Debra Hudson

Hydrological extremes, including droughts or floods, can have devastating effects on many aspects of human societies and the natural environment (IPCC, 2012). Seasonal ensemble forecasts of hydrological indicators could help adapt to and increase the resilience towards hydroclimatic variability and extremes by providing the opportunity to optimise decisions in advance and prepare for potentially harmful events. The ability to forecast hydrological variables several months ahead would be beneficial for many sectors, including agriculture, water management, bushfire risk assessments, emergency services and infrastructure.

The Bureau of Meteorology has developed a high-resolution national seasonal ensemble forecasting system for soil moisture, evapotranspiration and runoff across Australia, using a gridded water balance model (AWRA-L) forced with downscaled and calibrated seasonal climate forecasts from the Bureau’s ACCESS-S1 system.

In this presentation, we evaluate the hydrological forecasts relative to a historical reference simulation forced with observed climate inputs using hindcasts for the period 1990-2012. The forecasts were evaluated in terms of deterministic skill using the ensemble mean as well as probabilistically, assessing the accuracy and reliability of the forecast ensemble, with a specific focus on forecasts of hydrological extremes. Additionally, we assess the performance of the hindcast for selected use cases, particularly focusing on agriculture and water management, focusing on the Australian wheatbelt and major urban and rural water supply catchments.

Overall, we conclude that the forecasting system shows sufficient skill for a wide range of applications and regions. We outline limitations of the presented system and highlight potential future research directions.

How to cite: Vogel, E., Lerat, J., Pipunic, R., Frost, A. J., Griffiths, M., and Hudson, D.: Seasonal hydrological forecasts for Australia – applications in agriculture and water management, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15026, https://doi.org/10.5194/egusphere-egu21-15026, 2021.

François Bourgin, François Tilmant, Anne-Lise Véron, François Besson, Didier François, Matthieu Le Lay, Pierre Nicolle, Charles Perrin, Fabienne Rousset, Dominique Thiéry, Jean-Marie Willemet, Claire Magand, and Mathilde Morel

Low-flow forecasting can help to improve water management at places where a number of uses can be affected by diminishing water supply from rivers. Several French institutes (INRAE, BRGM, EDF, Lorraine University and Météo-France) have been collaborating to set up an operational platform, called PREMHYCE, for low-flow forecasting at the national scale, in cooperation with operational services. PREMHYCE includes five hydrological models and low-flow forecasts can be issued up to 90 days ahead for more than 800 basins. Several input scenarios are considered: ECMWF 14-days ensemble forecasts, ensemble streamflow prediction (ESP) using historical climatic data, and a no precipitation scenario. Outputs from the different hydrological models are combined into a multi-model approach to improve robustness of the forecasts. The tool provides text files and graphical representation of forecasted low-flows, as well as key low-flow indicators, such as the probabilities of being under low-flow thresholds provided by operational services. The presentation will show the main characteristics of this operational forecast platform, its latest developments and the results on the recent low-flow periods.

How to cite: Bourgin, F., Tilmant, F., Véron, A.-L., Besson, F., François, D., Le Lay, M., Nicolle, P., Perrin, C., Rousset, F., Thiéry, D., Willemet, J.-M., Magand, C., and Morel, M.: Low-flow forecasting in France: update on the latest developments of the PREMHYCE operational forecast platform, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2856, https://doi.org/10.5194/egusphere-egu21-2856, 2021.

Massimiliano Zappa, Luzi Bernhard, Manuela I. Brunner, Konrad Bogner, Katharina Liechti, Florian Lustenberger, Christoph Spirig, Irmi Seidl, and Manfred Staehli

Up to 2003, a collective memory on severe drought-events in Switzerland has been pretty much inexistent. There has been no targeted research on hydrological drought and no early detection instrument was available for guiding decision makers. Research within the framework of the National Research Program 61 (www.nrp61.ch) “Sustainable Water Use” (2010-2013) provided the cornerstones for prototyping the early drought detection platform www.drought.ch. In June 2013, the platform was launched and provided useful information during two severe drought events in 2015 and 2018. At the same time, awareness about future increases in the frequency of such events has been confirmed by several studies considering future streamflow projections. Drought and water scarcity are now found on the list of the most threatening hazards for Switzerland. Several political initiatives call for increased efforts in the deployment of a national early warning system for critical droughts. This led to the proposition, that www.drought.ch should be integrated as the main tool for official national drought warnings in Switzerland.

This contribution summarizes the 10-year process of developing the drought warning system drought.ch from technology readiness level 1 (TRL 1, “basic principles observed”) to TRL 8 (“system complete and qualified”). TRL1 started in 2010 with a two-stage dialogue with stakeholders from different sectors including national administration, hydropower, forestry, agriculture, and river navigation. TRL 3 (“experimental proof of concept”) began in 2013. Over the years, the initial focus on drought-specific monitoring of precipitation, streamflow, lake levels, groundwater levels, soil moisture deficit, snow resources, and dryness in forests and stream temperatures has been expanded to advanced countrywide sub-seasonal ensemble prediction of drought-parameters. The last major upgrade was the deployment of monthly forecasts (issued twice a week) during the extreme summer drought in 2018. Analyses of public drought perception after the 2018 event demonstrated that TRL 8 has been achieved, i.e. that the drought platform is useful.


How to cite: Zappa, M., Bernhard, L., Brunner, M. I., Bogner, K., Liechti, K., Lustenberger, F., Spirig, C., Seidl, I., and Staehli, M.: www.drought.ch – A 10-year span from technology readiness level 1 to 8, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5471, https://doi.org/10.5194/egusphere-egu21-5471, 2021.

Chiara Proietti, Alessandro Annunziato, Pamela Probst, Stefano Paris, and Thomas Peter

To improve preparedness and response in case of large-scale disasters, the international humanitarian community needs to understand the anticipated impact of an event as soon as possible in order to take informed operational decisions. The European Commission’s Joint Research Centre (JRC), DG ECHO, and the United Nations’ OCHA and UNOSAT launched the Global Disaster Alert and Coordination System (www.GDACS.org) in 2002-03 as cooperation platform to provide early disaster warning and coordination services to humanitarian actors. After more than 15 years, GDACS has around 30k registered users among humanitarian organisations at global level.

At the beginning, one of GDACS’s main tasks was the dissemination of automatic alerts for earthquakes, tsunamis and tropical cyclones; today, the system has been augmented to include also floods, droughts and volcanoes, and it will soon include forest fires.  Alerts are sent to the international humanitarian community to ensure timely warning in severe events that are expected to require international assistance. Alert levels are determined by automated algorithms without, or with very limited, human intervention, using automatic real-time data-feeds from various scientific institutes or the JRC’s own systems.

From 2020, because of the potential impact of the COVID-19 emergency on international preparedness and response activities, the COVID-19 situation in affected countries is now also monitored by the system, providing real time information updates on the website. This new feature allows to consider in the planning of the emergency response, the severity of the outbreak in the affected countries.

This contribution presents the challenges and outcomes of combining science-based information from different independent systems into a single Multi-Hazard Early Warning System and introduces new functionalities that were recently developed to address the new challenges related to the COVID-19 emergency.

How to cite: Proietti, C., Annunziato, A., Probst, P., Paris, S., and Peter, T.: Integration of operational Multi-Hazard Early Warning Systems and COVID-19 data for the humanitarian community, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15647, https://doi.org/10.5194/egusphere-egu21-15647, 2021.

Marion Sutton, Jacques Stum, and Claire Dufau

Unprecedented massive landings of Sargassum are regularly registered since 2011 along the shorelines of the Caribbean Sea, Gulf of Mexico and West Africa. Algae arrive from the open sea as large rafts (tenths of km) after drifting over long distances in the Central Atlantic NERR, and accumulating in consolidation areas in the Brazil retroflexion current and probably the Gulf of Guinea. Washing-ashore has tremendous negative impacts on local populations, coastal marine ecosystems and the economy sector, especially tourism and fisheries that are severely affected.

CLS has been developing a Sargassum algae monitoring and operational forecasting service (SAMTool) based on optical satellite sensors technologies and ocean-surface drift modelling. This service intends to provide support on decision-making to governmental and non-governmental agencies involved in monitoring, evaluating, mitigating or tackling the recurrent Sargassum environmental issue: Meteorological Offices, Coast Guards, Navies, Port Authorities, Marine Park managers, scientists, NGOs, Touristic and Fisheries organisations, etc.

With the support of ESA, a pool of nearly 40 end-users from several Caribbean islands and neighboring countries: Mexico, Belize, Aruba, Curacao, Bonaire, French Antilles, Barbados, Jamaica, Dominican Republic, Sint Maarten, Trinidad & Tobago, Antigua & Barbuda, were able to use the service from April 2019 to October 2020, and gave a general very positive feedback in terms of usefulness, operationality, and forecast quality of the  service.

In the frame of the H2020 e-shape project, CLS is testing the deployment of the service on a cloud infrastructure and exploring the DIAS capabilities to enhance the system and allow seasonal prediction. Further works are on-going to implement a new sargassum detection index algorithm to reduce false alarms and to explore the added-value of using SAR satellite data. The use of a cloud infrastructure in e-shape will allowed the computation of a reanalysis of sargassum detection at 300-m resolution  on Sentinel-3 data and will extent the computing capacity of the drift model to predict the Sargassum arrival months in advance.

The presentation will focus on the scientific and technical results of the seasonal approach developed in e-shape.

How to cite: Sutton, M., Stum, J., and Dufau, C.: Sargassum Monitoring –  Sargassum Detection in the Tropical Atlantic for Operational and Seasonal Planning , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12695, https://doi.org/10.5194/egusphere-egu21-12695, 2021.

Anna Kampouri, Vassilis Amiridis, Stavros Solomos, Anna Gialitaki, Eleni Marinou, Christos Spyrou, Aristeidis K. Georgoulias, Dimitris Akritidis, Nikolaos Papagiannopoulos, Lucia Mona, Simona Scollo, Ioannis Pytharoulis, Theodore Karacostas, and Prodromos Zanis

In the last years, several Etna eruption events are documented, forming lava flows and explosive activity. The Pilot EO4D_ash – Earth observation data for detection, discrimination & distribution (4D) of volcanic ash of the e-shape project provides the PANhellenic GEophysical observatory of Antikythera (PANGEA) of the National Observatory of Athens (NOA), in Greece with near-real-time alerts from Etna volcano eruptions. These alerts are used in the PANGEA station to monitor and reveal the presence of volcanic particles above the area the days following an eruption, also the station is supported by a volcanic particle monitoring and forecasting warning system. In this work, we investigate the volcano eruption between 30 May and 6 June 2019 which affected the southern parts of Greece and reaching the Antikythera station. Due to the prevailing meteorological conditions, volcanic particles and gases followed an easterly direction and were dispersed towards Greece. FLEXPART dispersion model simulations confirm the volcanic plume transport from Etna towards PANGEA, mixing also with co-existing desert dust particles. Model simulations are evaluated with PollyXT lidar measurements performed at PANGEA and satellite-based SO2 observations from the TROPOspheric Monitoring Instrument onboard the Sentinel-5 Precursor (TROPOMI/S5P). This is the first time that Etna volcanic products are monitored at the Antikythera station, in Greece with implications for the investigation of their role in the Mediterranean weather and climate.

Acknowledgments: We acknowledge the support by EU H2020 E-shape project (Grant Agreement n. 820852). Also, this research was supported by data and services obtained from the PANhellenic Geophysical Observatory of Antikythera (PANGEA) of the National Observatory of Athens (NOA), Greece, and by the project “PANhellenic infrastructure for Atmospheric Composition and climatE change” (MIS 5021516) which is implemented under the Action “Reinforcement of the Research and Innovation Infrastructure”, funded by the Operational Programme "Competitiveness, Entrepreneurship and Innovation" (NSRF 2014-2020) and co-financed by Greece and the European Union (European Regional Development Fund). NOA team acknowledges the support of the Stavros Niarchos Foundation (SNF).

How to cite: Kampouri, A., Amiridis, V., Solomos, S., Gialitaki, A., Marinou, E., Spyrou, C., Georgoulias, A. K., Akritidis, D., Papagiannopoulos, N., Mona, L., Scollo, S., Pytharoulis, I., Karacostas, T., and Zanis, P.: Investigation of volcanic emissions in Antikythera PANGEA station using near-real-time alerts, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13213, https://doi.org/10.5194/egusphere-egu21-13213, 2021.