Advancing our understanding of human-water dynamics through empirical findings on households' flood adaptation behavior in Hue, Vietnam

Communities around the globe are at substantial risk of being threatened by hydrological extremes, particularly by floods. Adapting to exacerbating flood risks is hence of utmost importance to safeguard people’s wellbeing. Households are critical for flood risk adaptation as their actions have proved effective and efficient in diminishing risks. At the same time, past flood experiences, as well as risk and adaptation capability perceptions are often considered important factors driving household adaptation. These linkages suggest complex human-water system dynamics, characterized by positive, i.e. reinforcing, and negative, i.e. hampering, feedback between household behavior and flood risks and impacts alike. Empirical evidence on this complex interaction is mixed, indicating diverting effects, and findings are predominately derived from case studies in the Global North. Therefore, additional data - particularly from the Global South - is needed to advance understanding of the complex human-water dynamics.

Building on this knowledge gap, our study presents insights into human-water dynamics from the highly flood-prone city of Hue in Central Vietnam. Drawing on a household survey (n=550) and follow-up semi-structured household interviews (n=30), we apply descriptive statistics, logistic regression, and qualitative content analysis to assess patterns and interlinkages of household flood adaptation behavior, past flood experiences, perceived future flood risks, and perceived adaptation capabilities.

Our results suggest that past flood experiences significantly shape households' flood risk perception. Interestingly, households that have been affected by floods in the past reported a higher perceived likelihood of being affected again in the future while their perceived future impact severity did not differ from non-affected households. In general, the perceived severity of flood impacts is assessed significantly lower than the perceived likelihood of impacts. This finding relates to an attitude of “living with the floods”, which strongly builds on the belief that floods cannot be avoided, but that people have always managed to cope with flood impacts. Therefore, risk perception generally only has a moderate effect on households' adaptation intention, although low levels of risk perception can act as a central barrier to future adaptation for some households. In contrast, perceived adaptation capabilities, particularly households' self-efficacy beliefs, have a strong effect on adaptation intention. While low self-efficacy, often driven by contextual factors including old age, poor health, or the lack of financial resources, acts as a significant barrier to adaptation, social networks were found to increase self-efficacy, thereby boosting adaptation intention.

In conclusion, our results decipher central human-water interlinkages and thereby provide vital hints for improved risk management and adaptation. For example, risk awareness-building campaigns should not be limited to increasing risk perception but also aim at strengthening perceived adaptation capabilities, such as through skills and knowledge building, to more effectively nudge households’ adaptation intention.