The European Socio-Hydrological Model: concept, methods and challenges

Flood risk is shaped by societal processes, such as “levee effect” and “adaptation effect”. Even though such feedbacks can now be captured by quantitative socio-hydrological models, they have been limited to small case studies due to lack of data. The aim of the European Socio-Hydrological Model (EuroSoHo) is to quantify past and future flood risk dynamics across the continent considering the spatially and temporarily varying human-water feedbacks.

This contribution presents the conceptual framework, outlines methodologies underlying the model, indicates how the necessary data will be obtained and what challenges will need to be addressed in further research. EuroSoHo will be a probabilistic, system dynamics model calibrated using a vast array of historical data covering years 1950-2025. Information from the HANZE (Historical Analysis of Natural HaZards in Europe) database will provide dates, locations and impacts (fatalities, population affected, economic loss) of floods, as well as their hydrological intensity in more than 1400 regions in 42 countries. Dedicated data collection of floodplain exposure changes and flood protection levels will further support establishing values of socio-hydrological parameters (e.g. preparedness, awareness, reactiveness or risk aversion) individually for each region within a uniform framework.

Based on the historical developments of human-water feedbacks, EuroSoHo will be applied to projections of future climate and socioeconomic pathways to estimate the actual changes in future flood risk until 2100. Further, EuroSoHo will quantify the costs and benefits of improving dikes, extending individual preparedness, restrictions on exposure growth, and relocation considering their system-wide positive and negative effects. The results will indicate which combination of adaptation strategies would be most effective under the uncertainty of future climate and socioeconomic developments as well as the unknowable timing of hydrological extremes.