Performance of the flood warning system in Germany in July 2021 – insights from affected residents

Abstract

Abstract. In July 2021 intense rainfall caused devastating floods in western Europe and 184 fatalities in the German federal states of North Rhine-Westphalia (NW) and Rhineland-Palatinate (RP), calling into question their flood forecasting, warning and response system (FFWRS). Data from an online survey (n=1315) reveal that 35 % of the respondents from NW and 29 % from RP did not receive any warning. Of those who were warned, 85 % did not expect very severe flooding and 46 % reported a lack of situational knowledge on protective behaviour. Regression analysis reveals that this knowledge is influenced not only by gender and flood experience but also by the content and the source of the warning message. The results are complemented by analyses of media reports and official warnings that show shortcomings in providing adequate recommendations to people at risk. Still, the share of people who did not report any emergency response is low and comparable to other flood events. However, the perceived effectiveness of the protective behaviour was low and mainly compromised by high water levels and the perceived level of surprise about the flood magnitude. Good situational knowledge and a higher number of previously experienced floods were linked to performing more effective loss-reducing action. Dissemination of warnings, clearer communication of the expected flood magnitude and recommendations on adequate responses to a severe flood, particularly with regard to flash and pluvial floods, are seen as major entry points for improving the FFWRS in Germany.

Spatial counterfactuals to explore disastrous flooding

“…Widespread intensive rainfall led to flash floods in many small and medium sized catchments; many of them experienced their flood-of-record. The high number of fatalities and tremendous damage (in Germany alone: 191 fatalities; € 33 billion damage) confirm that flood risk management is not well prepared for exceptional floods (Thieken et al 2023).…”

Always on My Mind: Indications of Post-Traumatic Stress Disorder Among Those Affected by the 2021 Flood Event in the Ahr Valley, Germany

“…The only flooding in Germany that exceeded this number was the storm surge from 1962 along the North Sea coast (Paprotny et al 2018; Thieken et al 2023). One possible reason for the high death toll was that the flood forecasting, warning, and response system (FFWRS) failed in areas affected by quickly rising flash floods, particularly in the Ahr Valley, catching many people by surprise during the night (Thieken et al, 2023b;Fekete and Sandholz, 2021). At least 770 people were injured, and several had to be dramatically rescued or were reported missing for several days (Kron et al, 2022).…”

Explaining Changes in Threat Appraisal, Coping Appraisal, and Flood Risk-Reducing Behavior Using Panel Data From a Nation-Wide Survey in Germany

“…This risk landscape and devastating flood events, such as the recent one in Western Europe in July 2021 (Cornwall, 2021), which caused more than 180 flood victims and more than €30 billion of damage in Germany alone (Deutscher Bundestag, 2021; Thieken et al, 2023), emphasize the urgent need for an all-of-society engagement to reduce the societal burden of floods, as it is also requested by the Sendai Framework for Disaster Risk Reduction 2015 to 2030 (United Nations, 2015).…”