Flood Adaptation under Climate Change with the European Socio-Hydrological Model

European riverine and coastal floodplains are highly managed systems, where different human actions can both increase or decrease flood risk. For instance, the “levee effect” could reduce the effectiveness of structural flood protection by encouraging exposure growth and lack of individual precaution, increasing impacts when a severe flood eventually overwhelms the dikes. On the other hand, frequent flooding has been shown to reduce vulnerability through adoption of local precautionary measures (“adaptation effect”). Current European projections of future flood risk under climate change do not consider these types of effects and other dynamic interactions in floodplains. Though such feedbacks could be captured by socio-hydrological models, those have been so far limited to small case studies due to lack of data. The aim of this project is to develop a European Socio-Hydrological Model (EuroSoHo) to quantify past and future flood risk dynamics across the continent. This probabilistic, system dynamics model will be calibrated on historical (1950–2025) data on flood occurrence, their impacts (fatalities, population affected, economic loss), floodplain exposure changes, and large-scale flood prevention schemes across more than 1400 regions in 42 European countries. The model will incorporate multiple socio-hydrological parameters (e.g. awareness, preparedness, reactiveness or risk aversion), quantifying the historical baseline of the society’s reaction to floods. EuroSoHo will then be able to project the future evolution (2026–2100) of the human-water system in Europe under the expected changes of both hydroclimatic and socioeconomic forcing. The system-wide positive and negative effects of improving dikes, extending individual preparedness, restrictions on exposure growth, and relocation will be quantified with EuroSoHo. The results will indicate which combination of adaptation strategies would be most effective in each region given their local-scale costs and benefits