More than two decades of post-disaster household surveys to improve flood risk management

Integrated flood risk management requires an extension from hazard to risk analysis and an involvement of various stakeholders including the general public. Since no standard protocols for collecting data about flood-affected societies are in place, post-disaster surveys have been initiated to gain information from affected residents and companies. Using the most damaging flood events that have occurred in Germany since 2000 as examples, the lecture will address how data collected from flood-affected people have been used a) to develop and improve loss models, b) to better understand how and why people adapt to flood risk, c) to evaluate how people respond to warnings, d) to provide insights into flood-related health impacts and e) to comprehend how people recover from flood impacts. Since flood processes in Germany between 2002 to 2024 differed considerably, it will be addressed how much the flood type – in particular slow-onset river flooding, flash floods and pluvial floods – influence impacts and coping mechanisms. Research outcomes have informed flood early warning systems, risk communication and recovery programs in Germany and beyond. However, surveying or interviewing flood-affected people might also put an additional burden on them. Hence, the lecture will discuss some ethical considerations about collecting data in (highly) affected areas as well as some pros and cons of cross-sectional versus longitudinal survey designs. Finally, transfer to other regions and hazards will be highlighted.