Project 1 - Hydrology of extraordinary floods – event analysis

Svenja Fischer, Andreas Schumann und Philipp Bühler
Institute of Hydrology and Water Resources Management, Ruhr-University Bochum

The subproject 1 “Hydrology of extraordinary floods – event analysis” examines how extreme floods are generated, which factors affect their peaks, volumes and shapes and how these factors interact with each other. In this context a detailed analysis of extreme flood events in different regions is conducted. For this purpose, the largest floods in selected river basins in Germany and Austria are analysed in regards to flood generating processes and the interaction between these processes. Particular consideration is given to precipitation, soil moisture and the interaction with runoff generation and the routing of the flood waves. The subproject consists of two phases. In the first phase, regional flood events of the mesoscale river basins were selected and analysed. New methodologies for the separation of flood events and a new flood typology based on the hydrograph have been developed. With this basis, new statistical models have been applied that take into account the different flood types and consider these jointly in a mixture distribution. In the second phase the results of the first phase are automated. Moreover, a detailed analysis of the impact of flood superposition and the differences of this for flood types is performed. Here, statistical-deterministic models are developed that are able to simulate different downstream scenarios, taking into account flood type, flood superposition and rainfall distribution.

References

Fischer, S.: A seasonal mixed-POT model to estimate high flood quantiles from different event types and seasons. Journal of Applied Statistics, 45 (15), 2831-2847, https://doi.org/10.1080/02664763.2018.1441385, 2018.
Fischer, S., and Schumann, A.: A distribution-free ordinal classification of floods based on moments. Hydrological Sciences Journal, Hydrological Sciences Journal 63 (11), 1605-1618, https://doi.org/10.1080/02626667.2018.1525614, 2018
Fischer, S., and Schumann, A.: Spatio-temporal consideration of the impact of flood types on flood statistics. Stochastic Environmental Research and Risk Assessment, https://doi.org/10.1007/s00477-019-01690-2, 2019
Fischer, S., Schumann, A., and Bühler, P.: Timescale-based flood typing to estimate temporal changes in flood frequencies. Hydrological Sciences Journal 64 (15), 1867-1892, https://doi.org/10.1080/02626667.2019.1679376, 2019
Oppel, H., and Fischer, S.: A new unsupervised learning method to assess clusters of temporal distribution of rainfall and their coherence with flood types. Water Resources Research, 56, e2019WR026511. https://doi.org/10.1029/2019WR026511, 2020.