OBSERVER: Towards a European Copernicus Coastal Flood Awareness System: the ECFAS project

OBSERVER: Towards a European Copernicus Coastal Flood Awareness System: the ECFAS project

OBSERVER: Towards a European Copernicus Coastal Flood Awareness System: the ECFAS project
nee@spacetec.p…

Thu, 13/10/2022 – 11:05

Coastal flooding is becoming one of the most threatening natural hazards in Europe. The exposed population is very large, with 50 million EU citizens living in low-elevation coastal zones at less than 10 m above mean sea level. Today, economic losses are estimated to be Euro 1.4 billion per year[1]. Coastal flood awareness systems exist for some countries in Europe, but very few have flood warning and assessment capabilities.

The H2020 European Project, “A proof of concept for the implementation of a European Copernicus Coastal Flood Awareness System”, (www.ecfas.eu) is coordinated by the University School for Advanced Studies (IUSS) in Pavia, Italy. ECFAS contributes to the development of tools and products for the evolution of the Copernicus Emergency Management Service (CEMS). While CEMS’ European Flood Awareness System (EFAS) currently includes early warning for riverine and flash floods, it does not yet include a specific coastal marine flood component. ECFAS builds on the CEMS framework to demonstrate the technical feasibility of a coastal flood awareness system and coast-targeted mapping products for CEMS Rapid Mapping as well as Risk and Recovery Mapping activities.

A user and policy driven approach

The ECFAS approach includes the involvement of several actors both in the implementation process and in the evaluation phase of the final outcomes. From the beginning of the project, end-users from different EU regions were engaged in order to collect their needs and requirements for a coastal Early Warning System (EWS). They represent different organisations and institutions, including public entities, private companies, civil protection agencies, universities and research centres.

An analysis of user requirements revealed the importance and relevance of ECFAS activities for the assessment, warning and management of coastal flood risk. User inputs were also used to guide the implementation process of the different products and tools. This engagement was boosted thanks to the involvement of the Copernicus User Forum from different countries and of the Entrusted Entities of the relevant Copernicus Services.

At the same time, an analytical overview of fast evolving international and European policies and legislation pertaining to the assessment and reduction of the coastal flood risk was completed. The overview reveals that the policy and legal regime for coastal flood risk reduction, prevention, response, management and recovery has been significantly strengthened in recent years, and creates various relevant obligations for EU Member States. In addition to policy imperatives arising from the global agendas on Sustainable Development, Disaster Risk Reduction and Climate Change, there are EU policy and legal instruments, including the 2021 EU Climate Change Adaptation Strategy, the 2021 EU Climate Law, the EU Action Plan for the Sendai Framework for Disaster Risk Reduction, and the Floods Directive (2007/60/EC) which require flood-risk assessment, management and response measures as well as related tools, data and services, including early warning services.

The ECFAS project is composed of several modules that are relevant for the emergency management cycle, including the prevention, preparedness, response and recovery phases. To this end, the already existing information provided by different Copernicus Services was used extensively as an essential set of information for the project implementation, such as those provided by the Land Monitoring (e.g., the Coastal Zone layer), Marine Environment Monitoring, Climate Change (e.g., ERA5 atmospheric forcing) and Emergency Management Services (e.g., EFAS framework, mapping products, etc.). In addition, radar altimetry data, in situ data, and mid- to very high-resolution satellite imagery were exploited in developing the different components of the system.

Hazard and impact of coastal storms

ECFAS provides up to 5-day forecasts of the total water level (TWL) for coastal points spaced 2.5 km along the European coastline using a numerical modelling approach developed within the project and in the Copernicus Marine Environment Monitoring Service (CMEMS). The TWL includes contributions from ocean circulation, steric sea level changes, tides, storm surges and wave setup.

For each coastal point, ECFAS has also identified TWL thresholds that can trigger coastal flooding. A one-year return period TWL is used to activate the system, while other thresholds indicative of longer return periods are used as references to design representative extreme scenarios. Using the 100 m resolution LISFLOOD-FP numerical model, pan-EU flood depths and velocity maps were produced for various extreme TWL scenarios along coastal sectors of ~100 km alongshore length (Figure 1).

In addition to flood maps, potential impacts induced by coastal floods were quantified. The impact layers generated include an evaluation of the exposed population, the potential damage to built-up structures and infrastructures, and other exposed elements such as, e.g., ecosystems and other Land Use categories (Figure 2).

Figure 1: Comparison between A) the modelled flood map for Xaver Storm (December 2013) in Norfolk (UK), using CMEMS forecast and B) the one modelled for a ~20-year return period extreme Total Water Level and 24-hours storm duration. The satellite-based observed flood extent is from the SPOT 5 satellite image of 06/12/2013 made available by CNES within the framework of the Spot World Heritage Program (background source: Map data ©2022 Google).Figure 2: Example of impact layers simulated for the Emma storm event (March 2018) in the city of Cádiz (Spain) (background source: Map data ©2022 Google).

Coastal erosion induced by storms: a coast-targeted mapping product

In order to evaluate the impact of storms in terms of beach erosion, ECFAS has implemented a semi-automatic algorithm for mapping the shoreline position from high- and medium- resolution multispectral satellite images from Sentinel-2 and Landsat. The erosion impact is considered essential to improve the products made available by the Copernicus Emergency Management Service with an improved mapping of the impact of extreme events (Figure 3).

The ultimate integration of all the products is performed in the ECFAS platform. The platform is not yet an operational tool, but it represents the ECFAS proof-of-concept aimed at demonstrating the technical and operational feasibility of the system. The platform runs on the WEkEO DIAS and can be used by users to retrieve information, forecasts, flood maps, impact maps, etc. End-users are currently co-evaluating the platform and suggested improvements will be integrated in the final system to be released in mid-November 2022.

Figure 3: Impact of the Gloria Storm (January 2020) in the area of the Ebro delta, Spain. Mapping of flooded area from Orthophoto of Catalunya 10 cm (Institut Cartogràfic i Geológic de Catalunya (ICGC), under a CC BY 4.0 license) and high-resolution satellite images SPOT 7 © Airbus DS (2020), provided under COPERNICUS by the European Union and ESA, all rights reserved. Background image ESRI World Imagery © Esri, DigitalGlobe, GeoEye, i-cubed, USDA FSA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community. Elaboration carried out by CLS (https://www.cls.fr/en/) for the ECFAS project (www.ecfas.eu)

A roadmap for integration into CEMS

One of the main outcomes of the project will be a roadmap in the form of a programmatic document which describes the main outcomes of the project and how its outcomes could potentially be integrated into CEMS. In addition, the roadmap will include an evaluation of the improvements required before an integration into CEMS operational products can be proposed, together with an analysis of limitations of the approach. User needs have highlighted the importance of developing an EWS and mapping products for coastal areas within the Copernicus framework which could become a supporting tool for the information systems of local and regional authoritities or provide useful information in areas where such systems are not available.

ECFAS has received funding from the European Union’s Horizon 2020 programme under Grant Agreement No 101004211. It is financed under the call LC-SPACE-18-EO-2020 Copernicus evolution: Research activities in support of the evolution of the Copernicus services. It started on 1st January 2021 and will end on 31st December 2022 (24 months). It involves eight partners from five European countries. The implementing consortium includes the University School for Advanced Studies IUSS (project coordinator, Italy), University of the Aegean (Greece), Mercator Ocean International (France), Planetek Hellas (Greece), Universitat Politècnica de València (Spain), Consorzio Futuro in Ricerca (Italy), Collecte Localisation Satellites (France), Eurocean (Portugal).

[1] Vousdoukas, M. I., Mentaschi, L., Hinkel, J., Ward, P. J., Mongelli, I., Ciscar, J. C., & Feyen, L. (2020). Economic motivation for raising coastal flood defences in Europe. Nature communications, 11, 2119. https://doi.org/10.1038/s41467-020-15665-3

Thu, 13/10/2022 – 12:00

Read More