GIS-based approach to estimate direct economic damages of fluvial flooding under various future scenarios: A case study of the Neckar river basin (Germany)

Sammanfattning: Fluvial floods can cause significant damages to inundated assets. The frequency and magnitude of fluvial floods are related to precipitation amounts, which are expected to change throughout the 21st century due to global warming. Alongside the hazard characteristics of fluvial flooding, flood damage potentials depend on flood exposure and flood vulnerability, which are also subject to change due to socio-economic development. In the context of continuously evolving damage-causing factors, methods to assess future changes in flood damage potential are increasingly asked for by decision-makers in flood risk management. This thesis project addresses this need by a) providing a GIS-based assessment framework, suitable to quantitatively estimate direct economic damages due to potential fluvial flooding under various future scenarios, and b) by testing the developed assessment framework in a case study in the Neckar river basin, which is located in the federal states of Baden- Wuerttemberg and Hesse in southern Germany. The developed framework is based on the findings of a scoping study on existing GIS-based flood damage assessment approaches. To account for uncertainties surrounding these future projections, a qualitative confidence estimation is introduced to reflect on the strength of knowledge underlying the framework- based flood damage assessment. The case study prognoses a significant increase in average annual flood damages in the study area throughout the 21st century. The increase in flood damage is primarily related to changes in flood exposure and flood vulnerability and to a smaller extent due to climate-related changes in the flood hazard.