EGU23-4281, updated on 30 Nov 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Hourly model simulation to improve the estimation of extreme floods in small catchments in Western Germany

Li Han1, Björn Guse1, Dung Nguyen1, Oldrich Rakovec2, Xiaoxiang Guan1, Sergiy Vorogushyn1, Luis Samaniego2, and Bruno Merz1
Li Han et al.
  • 1German Research Centre for Geosciences (GFZ), Section Hydrology, Potsdam, Germany
  • 2Helmholtz Centre for Environmental Research (UFZ), Department Computational Hydrosystems, Leipzig, Germany

The July 2021 flood in Western Germany is one of the most severe flood events in small-scale catchments during the past decades. It has led to life loss and severe damage in the Ahr, Erft, and Rur basins. The BMBF-funded joint project KAHR ( deals with the effects of this flood and develops scientific knowledge to assist the reconstruction process. To analyze past floods and develop future flood management strategies, there is a need for small-scale flood modeling with finer spatial-temporal resolution in this area. Based on the derived simulated floods, we can investigate the spatiotemporal patterns of extreme weather and associated meteorological and hydrological conditions that could lead to similar or more significant flood events.

This study uses the mesoscale hydrological model mHM at hourly resolution for three small catchments Ahr, Erft, and Rur. This is one of the first applications of mHM forced with hourly meteorological forcing data and should enable more accurate processes and representation of such extreme floods. In a further step, a regional weather generator and a disaggregation procedure are applied to generate 10,000 years of synthetic hourly meteorological data for the Ahr, Erft, and Rur catchments. These data are used to create long time series of discharge with the calibrated mHM model. This enables the investigation of extreme floods and the assessment of flood risk under future climate conditions.

How to cite: Han, L., Guse, B., Nguyen, D., Rakovec, O., Guan, X., Vorogushyn, S., Samaniego, L., and Merz, B.: Hourly model simulation to improve the estimation of extreme floods in small catchments in Western Germany, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-4281,, 2023.