OBSERVER: How the EU Space Programme supports flood preparedness—the role of the European Flood Awareness System (EFAS)
OBSERVER: How the EU Space Programme supports flood preparedness—the role of the European Flood Awareness System (EFAS)
evan
Wed, 29/01/2025 – 12:21
Floods remain one of the most complex and devastating natural hazards, impacting lives, infrastructure, and economies around the world. The increase in their frequency and magnitude due to climate change make the development and use of early warning systems (EWS)—capable of mitigating risks through advanced forecasting and preparedness mechanisms—more important than ever.
The EU is aware of and working towards these needs, with the EU Space Programme playing a key role in supporting flood preparedness and providing timely data and actionable insights for relevant national authorities—both in Europe and globally
As part of its activities, the EU Space Programme supports flood preparedness through several complementary initiatives. The Copernicus Sentinel satellites, in particular those included in the Sentinel-1 mission, provide near-real-time Earth Observation data used to map the extent of floods and to assess recovering areas.
The European Flood Awareness System (EFAS), which is part of the Copernicus Emergency Management Service (CEMS), is at the centre of the EU’s preparedness efforts. This Observer outlines its evolution, product portfolio, and contributions to improving flood preparedness in Europe while also highlighting emerging innovations and future developments within the system.
The flooded areas along the Polish-Czech border caused by Storm Boris are shown in red. The Copernicus Sentinel-1A radar satellite acquired this image on 15 September 2024. Credit: European Union, Copernicus Sentinel-1 data.
What is the European Flood Awareness System?
The catastrophic floods in the Elbe and Danube basins in 2002 prompted the creation of EFAS. The fragmented nature of flood warning systems at the time underscored the need for a transnational, coherent, and predictive framework. In response, the Joint Research Centre (JRC) of the European Commission started developing a unified, large-scale flood forecasting system. Following extensive testing and iterative refinements, EFAS became fully operational under the Copernicus Emergency Management Service in 2012.
EFAS bridges the gap between satellite technology and on-the-ground disaster management. It provides national and local authorities with a pan-European perspective by combining real-time satellite data, meteorological and hydrological models, and historical records. In doing so, the EU’s Flood Awareness System forecasts potential flood events days in advance, supporting countries in saving lives, protecting infrastructure, and minimising economic losses. The primary objectives of EFAS are fourfold:
- Anticipatory flood awareness: EFAS provides probabilistic flood risk forecasts with lead times of up to ten days to allow for proactive decision-making;
- Integration and support: EFAS complements existing national and regional forecasting systems by delivering a variety of added-value products, particularly for transboundary flood events;
- Transnational coordination: EFAS facilitates cooperative flood risk management among Member States by providing harmonised and spatially comprehensive forecasts;
- Emergency response readiness: EFAS supports the Directorate-General for European Civil Protection and Humanitarian Aid Operations (DG ECHO) through targeted information provision to the Emergency Response Coordination Centre (ERCC).
Overall, EFAS plays a key role in increasing flood preparedness and resilience in cooperation with a network of over 100 partners, including national hydrological services, civil protection agencies, and the European Commission’s ERCC.
How does EFAS Support Flood Preparedness and Early Warning Activities?
EFAS leverages a sophisticated, multi-layered operational architecture to deliver actionable flood predictions. Its functionality stems from advanced computational models, real-time observational data, and probabilistic forecasting methodologies, which together enable authorities to anticipate and prepare for imminent flood risks.
Probabilistic Forecasting Products
EFAS’ medium-range flood forecasts provide predictions up to 10 days in advance of a flood, giving emergency services valuable lead time to mobilise resources, evacuate populations, and strengthen protective measures.
Similarly, flash flood indicators pinpoint areas at immediate risk of rapid-onset floods, where early interventions can save lives. To complement these forecasting tools, EFAS also provides detailed hydrological outlooks—which assess the potential high river flows and floods in the coming months—and Flood Impact Forecasts to estimate the potential consequences of events on communities and infrastructure.
Together, these products form a comprehensive system that delivers seamless flood forecast information from the short-term to the seasonal scale. The forecasts are updated twice a day (except the seasonal outlooks) to ensure accuracy and timeliness, serving primarily as inputs for expert hydrological analysis at national and regional levels.
EFAS Notifications
EFAS’ notifications are a key element of the system. They serve as early warnings to alert authorities of potential flood risks. These notifications are categorised based on flood types, such as riverine floods or flash floods, and the probability of exceeding specific thresholds, such as 5-year or 20-year return periods.
Notifications are primarily directed to EFAS partners, which include national, regional, and local authorities with responsibilities in flood forecasting or management. Additionally, transboundary notifications are shared with neighbouring countries to facilitate coordinated responses across river basins. DG ECHO’s ERCC also receives notifications to support EU-level emergency planning and response efforts.
EFAS notifications are not aimed at warning the public, which is the responsibility of the relevant national authorities, but their purpose is to raise the attention of the relevant authorities of an upcoming flood event. Therefore, EFAS forecasts and notifications have a 30-day embargo period before being publicly accessible. They enable expert users to consult detailed forecasts via the EFAS map viewer to ensure informed decision-making in flood-prone areas.
EFAS Map Viewer
The EFAS map viewer is a centralised dissemination tool, providing interactive visualisations of forecasted flood extents, probabilities, and hydrological conditions. The platform enables partner authorities to explore detailed model outputs, facilitating nuanced evaluations of forecast reliability and uncertainty.
The European Flood Awareness System map viewer showing ’Medium-range forecast skill’ on 2 December 2024. Credit: European Union, Copernicus EMS, 2024.
How EFAS Supported the devastating floods in Central Europe in 2024
In September 2024, Central Europe was hit by a low-pressure storm called ‘Boris’, which brought record-breaking rainfall and caused widespread flooding in several European countries, including Austria, Czechia, Slovakia, Poland, Romania, and Hungary.
EFAS played a key role in alerting national authorities to the potential severity of the floods. On Monday 9 September, EFAS first highlighted the likelihood of severe flooding in Poland, Czechia, and Austria, with the first notification issued to Austria on the same day.
On Tuesday 10 September, EFAS began to issue more warnings of the expected floods, and by 12 September, forecasts showed that large areas of Central Europe were at risk of extreme flooding, with water levels in many places exceeding 20-year return period.
By Friday 13 September, just before the onset of the floods, EFAS had issued more than 100 notifications in Poland, Czechia, Austria, Hungary, Germany, Slovakia, Croatia, and Slovenia.
EFAS forecast and discharge hydrographs from 12 September where peak floods levels could exceed the 2-year (yellow), 5-year (red), and 20-year (purple) return period within a 10-day timespan. Credit: European Union, Copernicus EMS, 2024.
Innovations and future developments in EFAS
As the impacts of climate change intensify, the need for accurate and reliable flood early warning systems has never been greater. EFAS continues to evolve to meet this challenge, integrating cutting-edge technologies to deliver even more precise and actionable insights. At the same time, EFAS prioritises engagement with its partner network through targeted training, webinars, and collaborative workshops to ensure the system evolves in line with user needs and their operational challenges.
A major system release is planned for late 2025, incorporating new data and improvements in the hydrological model to increase accuracy and reliability of the forecasts. Improved flash flood prediction products, developed in collaboration with the EDERA Project, will refine short-term forecasting for smaller catchments. Seasonal products are also being updated to provide extended lead-time insights into hydrological trends to support longer-term risk management. In addition, progress in user accessibility is making EFAS tools more intuitive.
For the future, EFAS will continue to integrate new technologies and data such as Artificial Intelligence (AI) or the incorporation of products form the EU’s Destination Earth initiative, which are expected to further improve high-resolution climate and weather modelling.
Within the broader framework of the EU Space Programme, further developments are underway in relation to flood preparedness. For instance, the Galileo-based Early Warning Satellite System (EWSS) will use Galileo satellites’ advanced positioning capabilities to provide rapid and localised alerts and increase situational awareness during flood emergencies.
The European Flood Awareness System is a prime example of how the EU Space Programme translates satellite technology into tangible benefits for society. Together with other EU Space initiatives, EFAS plays a key role in addressing the challenges posed by climate change.
For more information on EFAS, its tools, and how it supports flood preparedness, visit the EFAS website.
Wed, 29/01/2025 – 12:00
