Process?Based Flood Risk Assessment for Germany

Large-scale flood risk assessments are crucial for decision making, especially with respect to new defense schemes, adaptation planning and estimating insurance premiums. We apply the process-based Regional Flood Model (RFM) simulate a 5000-year event catalog all major catchments in Germany derive curves based on losses per economic sector. The RFM uses continuous process simulation including multisite, multivariate weather generator, hydrological model considering heterogeneous catchment processes, coupled 1D–2D hydrodynamic dike overtopping hinterland storage, spatially explicit sector-wise exposure data empirical multi-variable loss models calibrated Germany. For components, uncertainties estimated. estimate median Expected Annual Damage (EAD) Value at Risk 99.5% confidence be €0.529 bn €8.865 bn, respectively. commercial sector dominates by making about 60% of total risk, followed residential agriculture gets affected small return period floods only contributes less than 3% risk. overall EAD is comparable other large-scale estimates. However, estimation specific periods substantially improved. spatial consistency estimates avoids large overestimation rare events that common homogeneous periods. Thus, process-based, consistent assessment an important step forward will serve as benchmark future German-wide assessments.