Assessing future changes in Alpine flash floods using convection permitting climate models and high resolution distributed hydrological models
Abstract
Flash floods are damaging natural hazards which often occur in the European Alps. Precipitation patterns and intensity may change in a future climate affecting the occurrence and magnitude of flash floods.
We estimate the frequency and occurrence of flash floods in the Alpine region for the RCP 8.5 future climate scenario for the end-of-century and compared to simulations of their current frequency and occurrence. Convection-permitting climate models can simulate the short-duration limited extent intense precipitation which triggers flash floods (Ban et al., in review at Climate Dynamics 2019). We use a state-of-the-art high-resolution convection-permitting regional climate model (Unified Model UM; Berthou et al., 2018 Climate Dynamics) to drive high-resolution distributed hydrological models using an hourly timestamp (e.g. Imhoff et al., 2020 Water Resour. Res.) for three Alpine catchments; Adige, Upper Rhine and Rhone. Wflow_sbm distributed hydrological models forced with ERA-Interim driven UM simulation of the current climate were validated against streamflow observations. A datasets of historical flood occurrences (Paprotny et al., 2018, Earth Syst. Sci. Data) was used to validate if the models can accurately simulate the location of the flash floods and to determine the threshold for flash flooding. Initial results indicate an increase in flood flash frequency for the Rhine and Adige catchments, while a higher intensity per event is observed for all three regions for the future simulations.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMH226...08Z
- Keywords:
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- 1805 Computational hydrology;
- HYDROLOGY;
- 1817 Extreme events;
- HYDROLOGY;
- 1821 Floods;
- HYDROLOGY;
- 1847 Modeling;
- HYDROLOGY