A new European coastal flood database for low–medium intensity events

Coastal flooding is recognized as one of the most devastating natural disasters, resulting in significant economic losses. Therefore, hazard assessment is crucial to support preparedness and response to such disasters. Toward this, flood map databases and catalogues are essential for the analysis of flood scenarios, and furthermore they can be integrated into disaster risk reduction studies. In this study and in the context of the European Coastal Flood Awareness System (ECFAS) project (GA 101004211), which aimed to propose the European Copernicus Coastal Flood Awareness System, a catalogue of flood maps was produced. The flood maps were generated from flood models developed with LISFLOOD-FP for defined coastal sectors along the entire European coastline. For each coastal sector, 15 synthetic scenarios were defined focusing on high-frequency events specific to the local area. These scenarios were constructed based on three distinct storm durations and five different total-water-level (TWL) peaks incorporating tide, mean sea level, surge and wave setup components. The flood model method was extensively validated against 12 test cases for which observed data were collated using satellite-derived flood maps and in situ flood markers. Half of the test cases represented well the flooding with hit scores higher than 80 %. The synthetic-scenario approach was assessed by comparing flood maps from real events and their closest identified scenarios, producing a good agreement and global skill scores higher than 70 %. Using the catalogue, flood scenarios across Europe were assessed, and the biggest flooding occurred in well-known low-lying areas. In addition, different sensitivities to the increase in the duration and TWL peak were noted. The storm duration impacts a few limited flood-prone areas such as the Dutch coast, for which the flooded area increases more than twice between 12 and 36 h storm scenarios. The influence of the TWL peak is more global, especially along the Mediterranean coast, for which the relative difference between a 2- and 20-year return period storm is around 80 %. Finally, at a European scale, the expansion of flood areas in relation to increases in TWL peaks demonstrated both positive and negative correlations with the presence of urban and wetland areas, respectively. This observation supports the concept of storm flood mitigation by wetlands.</p

Identification of local thresholds of TWL for triggering the European coastal flood awareness system, Deliverable 4.3 – Report on the identification of local thresholds of TWL for triggering coastal flooding - ECFAS project (GA 101004211). www.ecfas.eu

The European Copernicus Coastal Flood Awareness System (ECFAS) project will contribute to the evolution of the Copernicus Emergency Management Service (https://emergency.copernicus.eu/) by demonstrating the technical and operational feasibility of a European Coastal Flood Awareness System. Specifically, ECFAS will provide a much-needed solution to bolster coastal resilience to climate risk and reduce population and infrastructure exposure by monitoring and supporting disaster preparedness, two factors that are fundamental to damage prevention and recovery if a storm hits. The ECFAS Proof-of-Concept development will run from January 2021-December 2022. The ECFAS project is a collaboration between Scuola Universitaria Superiore IUSS di Pavia (Italy, ECFAS Coordinator), Mercator Ocean International (France), Planetek Hellas (Greece), Collecte Localisation Satellites (France), Consorzio Futuro in Ricerca (Italy), Universitat Politecnica de Valencia (Spain), University of the Aegean (Greece), and EurOcean (Portugal), and is funded by the European Commission H2020 Framework Programme within the call LC-SPACE-18-EO-2020 - Copernicus evolution: research activities in support of the evolution of the Copernicus services. This project has received funding from the European Union’s Horizon 2020 programme The deliverables will have restricted access at least until the end of ECFAS Description of the containing files inside the Dataset. The ECFAS Deliverable 4.3 - Report on the identification of local threshold of TWL for triggering coastal flooding aims to describe the methodology developed to identify local thresholds that will trigger the coastal flood mapping activity. To this end, it was necessary to identify both a total water level triggering threshold, used as a local reference to trigger the system in case of forecasted TWL exceedance, and a duration threshold, used to set the storm duration. In order to compute both thresholds, an Extreme Value Analysis (EVA) and a Duration Analysis (DA) were performed on the ECFAS combined hindcast. As the local TWL thresholds (triggering and duration) were identified using the ECFAS combined hindcast, and the system will instead be operative with the input of CMEMS forecast, a methodology was developed to establish a correction to be applied before integrating the thresholds into the warning system. The document also describes some limitations and possible future improvements of the employed methodology. The Deliverable 4.3 - Report on the identification of local thresholds of TWL for triggering coastal flooding is accompanied by an accessory data file. This file, named “ThresholdsFile.csv”, contains the values of the triggering and duration thresholds for all the ECFAS combined hindcast of TWL points and their coordinates. This ECFAS Thresholds is made available under the Open Database License: http://opendatacommons.org/licenses/odbl/1.0/. Any rights in individual contents of the database are licensed under the Database Contents License: http://opendatacommons.org/licenses/dbcl/1.0/. Disclaimer: ECFAS partners provide the data "as is" and "as available" without warranty of any kind. The ECFAS partners shall not be held liable resulting from the use of the information and data provided. This project has received funding from the Horizon 2020 research and innovation programme under grant agreement No. 10100421

A Pan-European high resolution storm surge hindcast

This contribution presents the high-resolution Pan-European storm surge (SSL) dataset, ANYEU-SSL, produced with the SCHISM circulation model. The dataset covers 40 years (1979–2018) of SSL data along the European coastline with 3-hour temporal resolution and has been extensively validated for the period spanning from 1979 to 2016, considering the whole time series, as well as for the extreme SSL values. Validation against tidal gauge data shows an average RMSE of 0.10 m, and RMSE below 0.12 m in 75% of the tidal gauges. Comparisons with satellite altimetry data show average RMSE of 0.07 m. SSL trends are estimated as an example of a potential application case of the dataset. The results indicate an overall latitudinal gradient in the trend of the extreme storm surge magnitude for the period 1979–2016. SSLs appear to increase in areas with latitudes &gt;50 °N and to decrease in the lower latitudes. Additionally, a seasonal variation of the extreme SSL, particularly strong in the northern areas, has been observed. The dataset is publicly available and aspires to provide the scientific community with an important data source for the study of storm surge phenomena and consequential impacts, either on large or local scales

Towards robust pan-European storm surge forecasting

Operational forecasting systems are important for disaster risk reduction. In this work we implement a coupled storm surge and tidal model on an unstructured grid over Europe towards the development of a pan-European Storm Surge Forecasting System (EU-SSF). The skill to predict tidal, surge and total water levels was evaluated based on measurements from 208 tidal gauge stations. Results show satisfactory performance for the two atmospheric forcing datasets tested, a High Resolution Forecast and ERA-INTERIM reanalysis, both provided by the European Center for Medium range Weather Forecast. For tidal predictions, the total RSS is equal to 0.197 m, lower than the values estimated by the global tidal model FES2004, and outperformed only by FES2012 (RSS = 0.05 m), which however is a product of data assimilation. Storm surge validation results show good predictive skill, with 0.04 m < RMSE < 0.21 m and %RMSE within 4%–22%. Coupling with tides results in improved storm surge level predictions, with RMSE reducing by up to 0.033 m. The areas benefiting most from the coupling are the North Sea and the English Channel, resulting in up to 2% reduction of the %RMSE. Increasing the resolution of atmospheric forcing also improves the predictive skill, leading to a reduction of RMSE up to 0.06 m in terms of the extremes, especially in shallow areas where wind is the main driver for surge production. We propose a setup for operational pan-European storm surge forecasting combining tidal levels from the FES2012 model and storm surge residuals from the EU-SSF setup which couples meteorological and astronomic tides

ECFAS Pan-EU Flood Catalogue, D5.4 – Pan-EU flood maps catalogue - ECFAS project (GA 101004211), https://www.ecfas.eu/

The European Copernicus Coastal Flood Awareness System (ECFAS) project will contribute to the evolution of the Copernicus Emergency Management Service (https://emergency.copernicus.eu/) by demonstrating the technical and operational feasibility of a European Coastal Flood Awareness System. Specifically, ECFAS will provide a much-needed solution to bolster coastal resilience to climate risk and reduce population and infrastructure exposure by monitoring and supporting disaster preparedness, two factors that are fundamental to damage prevention and recovery if a storm hits. The ECFAS Proof-of-Concept development will run from January 2021-December 2022. The ECFAS project is a collaboration between Scuola Universitaria Superiore IUSS di Pavia (Italy, ECFAS Coordinator), Mercator Ocean International (France), Planetek Hellas (Greece), Collecte Localisation Satellites (France), Consorzio Futuro in Ricerca (Italy), Universitat Politecnica de Valencia (Spain), University of the Aegean (Greece), and EurOcean (Portugal), and is funded by the European Commission H2020 Framework Programme within the call LC-SPACE-18-EO-2020 - Copernicus evolution: research activities in support of the evolution of the Copernicus services. This project has received funding from the European Union’s Horizon 2020 programme The deliverables will have restricted access at least until the end of ECFAS Description of the containing files inside the Dataset. The present database gathers flood and velocity maps for the European Union coast as well as their associated forcing parameters. The coast is divided into geographic regions embracing similar oceanographic conditions and subsequently into coastal sectors. The coastal sectors can be identified by its region index RXXX and its own index CSYYY. For each coastal sector, flood models were developed using the LISFLOOD-FP model with a grid resolution of 100 m. The flood model configuration follows the recommendation highlighted in ECFAS Deliverable D5.2 - Validated LISFLOOD-FP model for coastal areas. The flood and velocity maps are associated with synthetic storms that are characterised by a specific extreme water level and storm duration. These parameters were derived from Extreme Value Analyses performed on the ECFAS ANYEU-SSL hindcast (ECFAS D4.1 - Report on the calibration and validation of hindcasts and forecasts of TWL and D4.3 - Report on the identification of local thresholds of TWL for triggering coastal flooding). Five extreme water level values for each coastal point of the hindcast, and three durations (12, 24 and 36 h) were identified leading to 15 scenarios for each coastal sector. The flood and velocity maps are gathered into a NetCDF file for each coastal sector indicating the scenario parameters as attributes. In addition, the extreme water level values used for each coastal sector are contained in a complementary NetCDF file. The shapefile of the polygons defining the coastal sectors as defined for the catalogue implementation is included in the database. The Flood Catalogue is accompanied by a technical document describing methods, datasets, structure, format and content of the ECFAS Flood and Impact Catalogues: Duo, E., Le Gal, M., Souto Ceccon, P.E., Montes Pérez, J., 2022. Technical document on the ECFAS Flood and Impact Catalogue, D5.4 – Pan-EU flood maps catalogue - ECFAS project (GA 101004211). www.ecfas.eu The ECFAS Flood Catalogue was used to produce the associated ECFAS Pan-EU Impact Catalogue: Duo, E., Montes Pérez, J., Le Gal, M., Souto Ceccon, P.E., Cabrita, P., Fernández Montblanc, T., and Ciavola, P., 2022. ECFAS Pan-EU Impact Catalogue, D5.4 – Pan-EU flood maps catalogue - ECFAS project (GA 101004211). www.ecfas.eu [Data set]. Zenodo. https://doi.org/10.5281/zenodo.6778865 This ECFAS Flood Catalogue is made available under the Open Database License: http://opendatacommons.org/licenses/odbl/1.0/. Any rights in individual contents of the database are licensed under the Database Contents License: http://opendatacommons.org/licenses/dbcl/1.0/. *The size of the uncompressed dataset is 124 GB. Disclaimer: ECFAS partners provide the data "as is" and "as available" without warranty of any kind. The ECFAS partners shall not be held liable resulting from the use of the information and data provided. This project has received funding from the Horizon 2020 research and innovation programme under grant agreement No. 10100421

ECFAS Pan-EU Impact Catalogue, D5.4 – Pan-EU flood maps catalogue - ECFAS project (GA 101004211), www.ecfas.eu

&lt;p&gt;The European Copernicus Coastal Flood Awareness System (ECFAS) project aimed at contributing&nbsp;to the evolution of the Copernicus Emergency Management Service (https://emergency.copernicus.eu/)&nbsp;by demonstrating the technical and operational feasibility of a European Coastal Flood Awareness System. Specifically, ECFAS provides a much-needed solution to bolster coastal resilience to climate risk and reduce population and infrastructure exposure by monitoring and supporting disaster preparedness, two factors that are fundamental to damage prevention and recovery if a storm hits.&lt;/p&gt;&lt;p&gt;The ECFAS Proof-of-Concept development ran from January 2021 to December 2022. The ECFAS project was a collaboration between Scuola Universitaria Superiore IUSS di Pavia (Italy, ECFAS Coordinator), Mercator Ocean International (France), Planetek Hellas (Greece), Collecte Localisation Satellites (France), Consorzio Futuro in Ricerca (Italy), Universitat Politecnica de Valencia (Spain), University of the Aegean (Greece), and EurOcean (Portugal), and was funded by the &lt;strong&gt;European Commission H2020 Framework Programme&lt;/strong&gt; within the call LC-SPACE-18-EO-2020 - Copernicus evolution: research activities in support of the evolution of the Copernicus services.&nbsp;&lt;/p&gt;&lt;p&gt;&lt;i&gt;&lt;strong&gt;Description of the files contained in the Dataset.&lt;/strong&gt;&lt;/i&gt;&lt;/p&gt;&lt;p&gt;The ECFAS Pan-EU Impact Catalogue collects impact layers associated to the flood scenarios contained in the ECFAS Pan-EU Flood Catalogue. To produce the Flood Catalogue, the coast was divided into geographic regions embracing similar oceanographic conditions, and subsequently into coastal sectors. The coastal sectors can be identified by its region index RXXX and its own index CSYYY. Impacts associated to the flood maps were calculated following the approach described in the technical document of the ECFAS Deliverable 5.3 Algorithms for Impact Assessment (ECFAS Impact Tool; Duo et al., 2021). The ECFAS Impact Tool was adapted to assess the affected population, the damage to buildings, roads and railways and the exposure of a variety of other assets (e.g. agriculture, points of interest, etc.) for the flood scenarios included in the ECFAS Flood Catalogue.&lt;/p&gt;&lt;p&gt;The shapefile of the polygons defining the coastal sectors as defined for the catalogue implementation is included in the database.&lt;/p&gt;&lt;p&gt;The Impact Catalogue is accompanied by a technical document describing methods, datasets, structure, format and content of the ECFAS Flood and Impact Catalogues:&lt;/p&gt;&lt;p&gt;Duo, E., Le Gal, M., Souto Ceccon, P.E., Montes Pérez, J., 2022. Technical document on the ECFAS Flood and Impact Catalogue, D5.4 – Pan-EU flood maps catalogue - ECFAS project (GA 101004211). &lt;a href="http://www.ecfas.eu/"&gt;www.ecfas.eu&lt;/a&gt;&lt;/p&gt;&lt;p&gt;The ECFAS Pan-EU Flood Catalogue:&lt;/p&gt;&lt;p&gt;Le Gal, M., Fernández Montblanc, T., Montes Pérez, J., Duo, E., Souto Ceccon, P.E., Cabrita, P., &amp; Ciavola, P. (2022). ECFAS Pan-EU Flood Catalogue, D5.4 – Pan-EU flood maps catalogue - ECFAS project (GA 101004211), https://www.ecfas.eu/ (1.2) [Data set]. Zenodo. &lt;a href="https://doi.org/10.5281/zenodo.6935918&nbsp;"&gt;https://doi.org/10.5281/zenodo.6935918&nbsp;&lt;/a&gt;&lt;/p&gt;&lt;p&gt;The ECFAS Impact Tool:&lt;/p&gt;&lt;p&gt;Duo, E., Montes Pérez, J., and Souto-Ceccon, P.E. (2021). ECFAS Impact Tool, D5.3 – Algorithms for impact assessment - ECFAS project (GA 101004211), &lt;a href="http://www.ecfas.eu/"&gt;www.ecfas.eu&lt;/a&gt;, link: &lt;a href="https://doi.org/10.5281/zenodo.5809297"&gt;https://doi.org/10.5281/zenodo.5809297&lt;/a&gt;&lt;/p&gt;&lt;p&gt;This ECFAS &lt;strong&gt;Impact Catalogue&lt;/strong&gt; is made available under the &lt;strong&gt;Open Database License&lt;/strong&gt;: &lt;a href="http://opendatacommons.org/licenses/odbl/1.0/"&gt;http://opendatacommons.org/licenses/odbl/1.0/&lt;/a&gt;. Any rights in individual contents of the Impact Catalogue are licensed under the &lt;strong&gt;Open Database License&lt;/strong&gt;: &lt;a href="http://opendatacommons.org/licenses/dbcl/1.0/"&gt;http://opendatacommons.org/licenses/dbcl/1.0/&lt;/a&gt;.&lt;/p&gt;&lt;p&gt;The &lt;strong&gt;technical document&lt;/strong&gt; describing methods, datasets, structure, format and content of the ECFAS Flood and Impact Catalogues is made available under the &lt;strong&gt;Creative Commons Attribution 4.0 International License&lt;/strong&gt;.&lt;/p&gt;&lt;p&gt;*The size of the uncompressed dataset is 211 GB.&lt;/p&gt;&lt;p&gt;&lt;i&gt;&lt;strong&gt;Reference literature:&lt;/strong&gt;&lt;/i&gt;&lt;/p&gt;&lt;p&gt;&lt;i&gt;&lt;strong&gt;Duo, E., Montes, J., Le Gal, M., Fernández-Montblanc, T., Ciavola, P., and Armaroli, C.: Validated probabilistic approach to estimate flood direct impacts on the population and assets on European coastlines, Nat. Hazards Earth Syst. Sci. Discuss. [preprint], https://doi.org/10.5194/nhess-2023-197, in review, 2023.&lt;/strong&gt;&lt;/i&gt;&lt;/p&gt;&lt;p&gt;&lt;i&gt;&lt;strong&gt;Montes, J., Duo, E., Souto, P., Gastal, V., Grigoriadis, D., Le Gal, M., Fernández-Montblanc, T., Delbour, S., Ieronymidi, E., Armaroli, C., and Ciavola, P.: Evaluating coastal flood impacts at the EU-scale: the ECFAS approach, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11295, https://doi.org/10.5194/egusphere-egu22-11295, 2022.&lt;/strong&gt;&lt;/i&gt;&lt;/p&gt;&lt;p&gt;&lt;i&gt;&lt;strong&gt;Disclaimer:&lt;/strong&gt;&lt;/i&gt;&lt;/p&gt;&lt;p&gt;ECFAS partners provide the data "as is" and "as available" without warranty of any kind. The ECFAS partners shall not be held liable resulting from the use of the information and data provided.&lt;/p&gt;&lt;p&gt;This project has received funding from the Horizon 2020 research and innovation programme under grant agreement No. 101004211&lt;/p&gt;&lt;p&gt;&nbsp;&lt;/p&gt