Heavy Precipitation and Floods
In the past 30 years, the frequency of heavy precipitation events increased globally, and projections of river floods indicate increases in the course of the century for most regions. Prominent recent extremes in Central Europe are the floods in the Elbe and Danube catchments in 2002, 2006, 2010 and 2013. In 2021, several European countries were affected by severe floods, most devastating in the German Eifel region. In Germany alone, more than 180 people lost their lives and damages exceeded €33 billon. In addition, a series of localized flash floods on small river catchments were triggered by convective storms in 2016 and 2017. Because of their enormous socioeconomic damages, a thorough understanding of the evolution and impacts of heavy precipitation and flood events is mandatory.
The event chain approach for investigating hydrological extremes aims at a better understanding of the evolution of high precipitation events and their interlinkage with the hydrological system. Three strands of event chains are the focus of MOSES campaigns:
- In the Atmosphere, both persistent frontal rains from slow moving cyclones and intense atmospheric convection can cause heavy precipitation events leading to severe flooding.
- On the land surface, flood risk is enhanced in catchments where heavy precipitation coincides with specific antecedent hydrological conditions, such as saturated soil and/or snowmelt or hydrophobic soils due to preceding droughts.
- Floods affect aquatic systems by a pulse-like mobilization of sediments, contaminants and nutrients, thus threatening the quality status of lakes, rivers and coastal environments.
Highly mobile and interoperable measuring systems are required to monitor the multiple and interconnected processes of the different environmental systems. Such a concerted observation campaign for heavy precipitation and flood events is illustrated in the block diagram.
The heavy precipitation and floods campaigns started in 2019 as part of the implementation period. They were conducted in the Müglitz Valley and in the Neckar Valley/Swabian Jura, both of which are German hotspot regions for convective storms, heavy precipitation events, and flash floods. From 2022 onwards, the campaigns are carried out as part of the MOSES operating phase.
Evolution and Impacts of Meteorological Extremes
Prof. Peter Knippertz, KIT | peter.knippertz@kit.edu
Dr. Andreas Wieser, KIT | andreas.wieser@kit.edu
Evolution and Impacts of Floods and Low Flows in Aquatic Systems
Prof. Dietrich Borchardt, UFZ | dietrich.borchardt@ufz.de
Dr. Norbert Kamjunke, UFZ | norbert.kamjunke@ufz.de
Prof. Philipp Fischer, AWI | philipp.fischer@awi.de