Maps of potential coastal flood zones on the Arcachon lagoon for crisis management support

This communication presents the decision support tool developed by the BRGM on the Arcachon Lagoon for the Departmental Flooding Referent of Gironde (RDI33). It is a cartographic atlas of marine flooding scenarios (on the 10 coastal municipalities of the lagoon) composed of a set of theoretical but realistic weather-sea conditions. The scenarios, built using a statistical analysis of forcing conditions (wind, waves, surge) and numerical modelling of onshore flooding, represent a wide range of events, from annual to exceptional. Thanks to a dedicated digital application, this atlas allows the duty manager of RDI33 to interpret and translate the operational coastal forecasts of Meteo-France into potentially inundated areas on land by operating by analogy with the scenarios of the database. Beyond the atlas, the database produced for the RDI33 will be used as part of the ANR ORACLES project to develop artificial intelligence models capable of producing ensemble forecasts in (near) real time.