Reducing the Vulnerability of Societies to Water Related Risks at the Basin Scale (Proceedings of the third International Symposium on Integrated Water Resources Management, Bochum, Germany, September 2006). IAHS Publ. 317, 2007, 319–324.

Estimation of trends in rainfall extremes as important input parameters for flood risk assessment

SUSANNE BACHNER, ALICE KAPALA & CLEMENS SIMMER

Meteorological Institute, University of Bonn, Auf dem Hügel 20, D-53121 Bonn, Germany

s.bachner@uni-bonn.de

Abstract Different statistical characteristics of daily precipitation and discharge data covering the 20th century are investigated with regard to their long term behaviour. Trend analysis, extreme value statistics and wavelet analysis are used in order to examine different aspects of the temporal variability of precipitation characteristics. There is a tendency of increasing extremes in both rainfall and runoff, but this is only valid for a few stations and precipitation indices. Common temporal scales of variability in both parameters are detected by applying cross wavelet spectra with complex phase relations.

Key words daily precipitation and discharge data; extremes; Germany; return values; trend and wavelet analysis