Changing climate shifts timing of European floods

Günter Blöschl, Julia Hall, Juraj Parajka, Rui A P Perdigão, Bruno Merz, Berit Arheimer, Giuseppe T Aronica, Ardian Bilibashi, Ognjen Bonacci, Marco Borga, Ivan Čanjevac, Attilio Castellarin, Giovanni B Chirico, Pierluigi Claps, Károly Fiala, Natalia Frolova, Liudmyla Gorbachova, Ali Gül, Jamie Hannaford, Shaun Harrigan, Maria Kireeva, Andrea Kiss, Thomas R Kjeldsen, Silvia Kohnová, Jarkko J Koskela, Ondrej Ledvinka, Neil Macdonald, Maria Mavrova-Guirguinova, Luis Mediero, Ralf Merz, Peter Molnar, Alberto Montanari, Conor Murphy, Marzena Osuch, Valeryia Ovcharuk, Ivan Radevski, Magdalena Rogger, José L Salinas, Eric Sauquet, Mojca Šraj, Jan Szolgay, Alberto Viglione, Elena Volpi, Donna Wilson, Klodian Zaimi, Nenad Živković

A warming climate is expected to have an impact on the magnitude and timing of river floods; however, no consistent large-scale climate change signal in observed flood magnitudes has been identified so far. We analyzed the timing of river floods in Europe over the past five decades, using a pan-European database from 4262 observational hydrometric stations, and found clear patterns of change in flood timing. Warmer temperatures have led to earlier spring snowmelt floods throughout northeastern Europe; delayed winter storms associated with polar warming have led to later winter floods around the North Sea and some sectors of the Mediterranean coast; and earlier soil moisture maxima have led to earlier winter floods in western Europe. Our results highlight the existence of a clear climate signal in flood observations at the continental scale.