Individual flood risk adaptation in Germany: exploring the role of different types of flooding

Abstract. The influence of different flood types, i.e., fluvial, flash, and urban pluvial floods, on whether and how flood-affected people prepare for flooding is unclear but might be relevant for effective risk communication. Survey data from more than 3000 households affected by different types of flooding in Germany have been investigated and revealed the influence of flood type on adaptive behavior. Descriptive statistics, Kruskal–Wallis tests, and single-factor analysis of variance (ANOVA) have been used to identify differences and similarities between respondents. Linear regressions have been used to identify factors that influence households' adaptive behavior in the context of fluvial, pluvial, and flash flooding. Most respondents were motivated to protect themselves, but there were flood-type-specific differences in the factors influencing an adaptive response. Those affected by fluvial events had most often implemented measures before the last flooding and had experienced flooding before but frequently showed signs of maladaptive thinking. Those affected by flash flooding showed less confidence in the effectiveness of measures but were less likely to rate their costs as too high and were most likely to implement measures after the event. Regardless of the type of flooding, the perception of the effectiveness of adaptive measures and a positive perception of personal responsibility were found to be crucial for motivating those affected to protect themselves. These two key elements can be strengthened by offering financial support for adaptive measures. Communication on a municipality level enhances residents' sense of personal responsibility. Hence, communication and management strategies need to involve municipalities and should be tailored to the locally relevant flood type.