Understanding Flood Fatalities: Reevaluating Flood Risk Management

Résumé fourni par la source

Abstract Extraordinary flooding in July 2021 claimed 224 lives in Germany and Belgium, an unprecedented number in recent decades in both countries. To better understand the underlying causes, individual circumstances of all fatalities were analyzed based on official documents and interviews with family members. A high fraction of 58% of fatalities occurred outside officially mapped flood hazard zones suggesting that existing flood maps do not sufficiently convey risk to the public. In addition, fatal pathways reveal deficiencies in warning, evacuation and response behavior. 66% of the 131 people who died indoors were caught by surprise in basement apartments (i.e., apartments accessed by walking down from the ground floor) or more often on the ground and upper floors of their homes, suggesting that these buildings should have been evacuated in time. 22% died in basements, mostly while mitigating damage, checking pumps or starting cleanup, pointing toward deficiencies in communicating safe behavior during flooding. The circumstances of outdoor deaths (93 out of 224) are less clear, but demonstrate the risks of being outdoors during a flood, even in places that are usually considered safe, for example, bridges. Despite regional differences, our results suggest to clearly communicate appropriate behaviors in warning messages. Evacuation needs to take place in areas where moderate to high water levels are expected, particularly where ground‐level apartments are likely to be flooded. Special attention should be paid to the safety of elderly people, who were significantly overrepresented among the fatalities. Finally, the European Floods Directive and its implementation need to better address worst‐case scenarios in hazard mapping, risk management, and communication.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.