Modelling the role of multiple risk attitudes in implementing adaptation measures to reduce drought and flood losses

•Different risk attitudes have a strong influence on social awareness, preparedness, and consequent drought and flood losses.•The impacts of a hydrological extreme can be exacerbated by the adaptation actions taken to cope with the opposite extreme.•Co-existence of social groups with different risk attitudes influences the implementation of collective adaptation actions. Human activities have increasingly affected hydrological processes in many river basins worldwide leading to changes in the severity of droughts and floods. A number of modelling studies have used system dynamic models to represent the complex dynamics generated by the interplays between the social and physical systems. Yet, attitudes towards drought and flood risk leading to the implementation of individual and collective adaptation measures are not included in current system dynamics modelling approaches. To address this gap, we developed a system dynamic model to represent the dynamics between human societies, decision-making processes, adaptation measures, and hydrological extremes. The model accounts for a society characterized by the co-existence of four types of risk attitudes and management responses: risk-neglecting, risk-controlling, risk-downplaying, and risk-monitoring. Our findings show that the presence of a prevalent social group with a certain risk attitude has a strong influence on the awareness, preparedness, and consequent losses of the other social groups. On the other hand, the homogenous presence of social groups with diverse risk attitudes leads to higher drought and flood losses due to the unsustainable water use of risk-neglecting and risk-downplaying groups. Finally, our results highlight that societies characterized by high heterogeneity in risk-attitudes tend to implement less collective measures, opting instead for individual measures by specific social groups. This emphasizes the importance of accounting for different social groups when modelling human-water dynamics to promote an integrated risk management and design more sustainable and resilient future adaptation pathways.