Hydrol. Earth Syst. Sci., 24, 1633–1648, 2020 https://doi.org/10.5194/hess-24-1633-2020 © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. The role of flood wave superposition in the severity of large floods Björn Guse1, Bruno Merz1,2, Luzie Wietzke1, Sophie Ullrich1, Alberto Viglione3,4, and Sergiy Vorogushyn1 1GFZ German Research Centre for Geosciences, Hydrology Section, Potsdam, Germany 2University of Potsdam, Institute for Environmental Sciences and Geography, Potsdam, Germany 3Vienna University of Technology, Institute of Hydraulic Engineering and Water Resources Management, Vienna, Austria 4Politecnico di Torino, Department of Environment, Land and Infrastructure Engineering (DIATI), Torino, Italy Correspondence: Björn Guse (
[email protected]) Received: 25 June 2019 – Discussion started: 9 July 2019 Revised: 31 January 2020 – Accepted: 10 February 2020 – Published: 6 April 2020 Abstract. The severity of floods is shaped not only by event- from alpine tributaries. Overall, we conclude that the super- and catchment-specific characteristics but also depends on position of flood waves is not the driving factor behind flood the river network configuration. At the confluence of rele- peak severity at the major confluences in Germany; however, vant tributaries with the main river, flood event character- a few confluences show the potential for strong flood magni- istics may change depending on the magnitude and tempo- fications if a temporal shift in flood waves was to occur. ral match of flood waves. This superposition of flood waves may potentially increase the flood severity downstream in the main river. However, this aspect has not been analysed for a large set of river confluences to date.