Author(s): Christoph Mudersbach; Jens Bender; Fabian Netzel
Linked Author(s):
Keywords: Discharge; Flood; Extreme value distribution; Design level
Abstract: Within this investigation, we focused on analyses of the discharge data of the gauge Neu Darchau (Elbe River) ,which is the most downstream discharge gauge of the Elbe River before it becomes an estuary. We followed the questions, if the discharge characteristics of the Elbe River have changed over the last decades and how much the design discharges (i. e. HQ100) are affected by the latest extreme events in 2002, 2006, 2011 and 2013. Hence, we conducted (i) an assessment of time-dependencies of the design discharge HQ100 by using extreme value statistics with both block maxima and peak-over-threshold approaches and (ii) an estimation of confidence levels for the time-dependent behavior of the design discharges by means of Monte-Carlo simulations using autoregressive models. For the sake of comparison we also did the same analyses for the gauge Cologne (Rhine River) ,whereas for this gauge only the final results are shown. For the gauge Neu Darchau many flood indicators move towards the upper confidence bands. The hydrological situation at the gauge Cologne differs from the one at the gauge Neu Darchau, since no severe flood events within the last 10-15 years occurred at the Rhine River. Thus, the HQ100 levels are not that unstable over the last years. However, the extreme floods in 1993 and 1995 had a large impact on the HQ100 levels.
Year: 2015