Intense rainfall is defined as an unusually high amount of precipitation over a short period of time. In this case, an intense rainfall is an event during which more than 20 liters of precipitation per square meter fall in one day, which corresponds to a water column of 20 mm.
Intense rainfall can cause devastating floods locally, and this with very short warning times. If a large part of the precipitation cannot be absorbed by the ground, even harmless streams can very quickly turn into real torrents, overflowing their banks, and causing major destruction, as for example during the summer storm in Braunsbach in 2016 in Baden-Württemberg. Since the water does not immediately reach the receiving watercourses during such intense rainfall, areas outside the watercourses can also be endangered. In towns and villages, intense rainfall therefore causes flooding on roads, underpasses, underground parking lots, cellars, etc. In extreme cases, the rapid flow of water due to heavy rainfall can be life-threatening. In hilly terrain, in sloping areas, other dangers threaten: soil erosion, landslides, mudslides. Overall, the rapid flow of water is characterized by a high potential for destruction, as it also carries heavy objects such as cars, construction equipment, etc. and erodes and moves large amounts of debris.
NILS RIACH, NICOLAS SCHOLZE, RÜDIGER GLASER, SOPHIE ROY & BORIS STERN
Physische Geographie, Universität Freiburg i. Br.
Météo-France, Illkirch
GeoRhena, Département du Haut-Rhin, Colmar
This dossier consists of 4 maps on climate change in the tri-national Upper Rhine region and an accompanying text. The package contains 2 maps on the development of the number of intense rainfall days in the near future (2021-2050) and 2 maps for the distant future (2071-2100). For each of the two time horizons, two maps are also available: one map for a moderate climate change scenario (RCP4.5) and one map for the strong scenario (RCP8.5).
The full text of the report is available below in French and German.
