Catchment Name and Location: River Ahr catchment in Rhineland-Palatinate in Germany.
Flash Floods: Extreme flash floods occred in 1804, 1910 and in 2021 in the river Ahr catchment. The extreme flash flood disaster in 2021 basd on a >24 hours extreme rainfall event in the whole large catchment (~900 km2) catchment with deep valleys leads to huge damages and ~180 death people. The event was mainly triggered by an extreme weather scenario as well as on top by climate change impact (higher temperature → higher air humidity → increasing rainfall insensitivity and probability -> high short term regional torrential rainfall).
Charaecteristics: Besides the data uncertainty (e.g. measurement instrument were destroyed, rainfall radar data resolution is still too coarse in comparison to 1m DEM availability) also water pollution from human infrastructure (e.g. oil tanks, sewer systems, treatment plants burst/destroyed) occurs. Even this was an actual extreme disaster, similarity is existing to other local disasters such as the flood at river Weißeritz 2002 in Saxonia. This event and the case study catchment is representative by its characteristics for catchments of rivers in the lower mountainous region (“Mittelgebirge”) in Germany but also Belgium, France, Czechia, Poland, Slovakia and others in this part of Europe.
Flash Floods: Extreme flash floods occred in 1804, 1910 and in 2021 in the river Ahr catchment. The extreme flash flood disaster in 2021 basd on a >24 hours extreme rainfall event in the whole large catchment (~900 km2) catchment with deep valleys leads to huge damages and ~180 death people. The event was mainly triggered by an extreme weather scenario as well as on top by climate change impact (higher temperature → higher air humidity → increasing rainfall insensitivity and probability -> high short term regional torrential rainfall).
Charaecteristics: Besides the data uncertainty (e.g. measurement instrument were destroyed, rainfall radar data resolution is still too coarse in comparison to 1m DEM availability) also water pollution from human infrastructure (e.g. oil tanks, sewer systems, treatment plants burst/destroyed) occurs. Even this was an actual extreme disaster, similarity is existing to other local disasters such as the flood at river Weißeritz 2002 in Saxonia. This event and the case study catchment is representative by its characteristics for catchments of rivers in the lower mountainous region (“Mittelgebirge”) in Germany but also Belgium, France, Czechia, Poland, Slovakia and others in this part of Europe.
Flooding in Altenburg (Altenahr), Rhineland-Palatinate, Germany (source: Wikipedia).
