Modelling flood damages under climate change conditions – a case study for Germany

Abstract

Abstract. The aim of the study is to analyze and discuss possible climate change impacts on flood damages in Germany. The study was initiated and supported by the German insurance sector whereby the main goal was to identify general climate-related trends in flood hazard and damages and to explore sensitivity of results to climate scenario uncertainty. The study makes use of climate scenarios regionalized for the main river basins in Germany. A hydrological model (SWIM) that had been calibrated and validated for the main river gauges, was applied to transform these scenarios into discharge for more than 5000 river reaches. Extreme value distribution has been fitted to the time series of river discharge to derive the flood frequency statistics. The hydrological results for each river reach have been linked using the flood statistics to related damage functions provided by the German Insurance Association, considering damages on buildings and small enterprises. The result is that, under the specific scenario conditions, a considerable increase in flood related losses can be expected in Germany in future, warmer, climate.

Cross‐scale intercomparison of climate change impacts simulated by regional and global hydrological models in eleven large river basins

“…While the focus here was on absolute changes in discharge, for many applications it might be sufficient to evaluate relative changes only (Schewe et al 2014), or in the case of floods or droughts to use extreme value statistics (Feyen et al 2012, Hattermann et al 2014, Gosling et al 2015). Figure A2 (Annex)…”

The determinants of private flood mitigation measures in Germany — Evidence from a nationwide survey

“…1 Climate change is expected to increase the economic damage due to riverine floods in Europe (Ciscar et al 2011;Feyen, Barredo, and Dankers 2009;Rojas, Feyen, and Watkiss 2013). For Germany, further analyses demonstrate similar trends (GDV 2011;Hattermann, Huang, et al 2013). For floods induced by heavy rain, the evidence of a future climate-change-induced increase of economic damage is less clear, but some authors suggest that there is already a significant upward trend in heavy rain events due to climatological drivers such as air temperature (Hattermann, Kundzewicz, et al 2013;IPCC 2013).…”

Brief Communication: An update of the article "Modelling flood damages under climate change conditions – a case study for Germany"

“…An increase in specific air humidity and intense precipitation, as well as in frequency of "wet" atmospheric circulation patterns, has also been reported for Germany (Hattermann et al, 2012). This is why the German Insurance Association has commissioned a study with the aim to estimate what flood damage would occur in individual river reaches of Germany under a warmer climate (published in Hattermann et al, 2014), solely considering the pure climate change impact and keeping socio-economic drivers constant. Only a limited number of regional climate projections were available for the impact study, and these projections were all driven by a single global circulation model (GCM), while different recent studies show that GCMs are often the largest source of uncertainty in impact modelling (cf.…”