EGU24-6222, updated on 08 Mar 2024
https://doi.org/10.5194/egusphere-egu24-6222
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Warming climate will alter the characteristics and generation processes of European floods

Larisa Tarasova1, Bodo Ahrens2, Günter Blöschl3, Rohini Kumar4, Mostafa Hamouda2,5, Oldrich Rakovec4,6, and Ralf Merz1
Larisa Tarasova et al.
  • 1Department Catchment Hydrology, Helmholtz Centre for Environmental Research - UFZ, Halle, Germany
  • 2Institute for Atmospheric and Environmental Sciences, Goethe-University Frankfurt-am-Main, Frankfurt-am-Main, Germany
  • 3Institute of Hydraulic Engineering and Water Resources Management, Vienna University of Technology, Vienna, Austria
  • 4Department Computational Hydrosystems, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
  • 5Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
  • 6Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Prague-Suchdol, Czech Republic

Under ongoing climate change, the projected increase in the magnitude of extreme precipitation is expected to intensify the magnitudes of future river floods. However, the disparate past changes in the latter, suggest that changing flood generation processes modulate the sensitivity of streamflow response to changing precipitation.

Here we examine how flood generation processes will change in Europe until the end of the 21st century under high emission scenario (SSP585) using the climatic forcing (i.e., precipitation, temperature) from CMIP6 EC-EARTH3-Veg simulation (Döscher et al., 2022) dynamically downscaled using the atmosphere-ocean coupled regional climate system model COSMO-NEMO-TRIP (Primo et al., 2019) within the extended EURO-CORDEX domain at the spatial resolution of 0.11° and corresponding hydrological simulations (i.e., streamflow, soil moisture, snow water equivalent) using mesoscale Hydrological Model (mHM). Using this information, we classify the annual maximum floods into rainfall events that occurred on dry or wet soils, a mixture of rainfall and snowmelt, and pure snowmelt events. We evaluate the reliability of our modeling system by comparing the frequency of these flood generation processes and characteristics of annual floods for the historical period 1960-2010 using classified flood observations in 1353 European catchments (Tarasova et al., 2023).

We find that under exacerbating climate change the frequency of occurrence of flood generation processes in Europe will change considerably by the end of the century. Interestingly, the pace of change in the magnitude, runoff coefficients and time scales of floods differs considerably for floods generated by different processes, emphasizing an important role that these processes play in modulating climate change signal and shedding a light on the variable hazard that flood events generated by different processes pose in a warming climate.

 

Döscher et al. The EC-Earth3 Earth system model for the Coupled Model Intercomparison Project 6. Geoscientific Model Development 15, 7 (2022). https://doi.org/10.5194/gmd-15-2973-2022

Primo et al. A regional atmosphere–ocean climate system model (CCLMv5.0clm7-NEMOv3.3-NEMOv3.6) over Europe including three marginal seas: on its stability and performance. Geoscientific Model Development 12, 12 (2019). https://doi.org/10.5194/gmd-12-5077-2019

Tarasova et al. Shifts in flood generation processes exacerbate regional flood anomalies in Europe. Commun Earth Environ 4, 49 (2023). https://doi.org/10.1038/s43247-023-00714-8

How to cite: Tarasova, L., Ahrens, B., Blöschl, G., Kumar, R., Hamouda, M., Rakovec, O., and Merz, R.: Warming climate will alter the characteristics and generation processes of European floods, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6222, https://doi.org/10.5194/egusphere-egu24-6222, 2024.