After the 2021 European Floods—Changes in Risk Perception, Protection, and Preparedness: A Local Case Study in Leverkusen

The 2021 European floods were among the most destructive in recent decades, highlighting the importance of understanding how disruptive events shape risk perception and preparedness across multiple hazards, especially under climate change. This study examines how this flood affected risk perception and preparedness among 584 residents in Leverkusen, a city in the Rhine catchment severely impacted by the event. Using a standardised survey, it tests a priori hypotheses derived from cross-over literature and Protection Motivation Theory (PMT), complemented by exploratory analyses of specific hazard pairs and preparedness behaviours. Results show that retrospectively reported risk perception increased across all assessed hazards after the flood, indicating clear crossover effects: experience with one hazard also influenced perceptions of other hazards, with direct heavy-rain experience affecting all hazards, and indirect experiences led to broader effects. Consistent with key elements of PMT, direct flood experience was the strongest indicator of protective installations, whereas indirect experience was mainly linked to higher knowledge about natural hazards and flood protection. Survey responses suggest higher perceived risk and knowledge after the 2021 flood, but changes in protection and behaviour remained limited. The study contributes to empirical evidence of cross-over effects in an urban, multi-hazard context several years after a major flood, where direct and indirect experiences shape perception and preparedness differently, highlighting the need for targeted communication to support adaptation after disruptive flood events.