Operationalizing social resilience for fluvial flood risk management systems in urban basin area by considering the uncertainty of physical and demographic characteristics

The conventional approach to River Basin Flood Management (RBFM) focuses on increasing the safety and security of drainage systems against heavy rainfalls. Recent floods in urban catchments have highlighted the need for a more resilient approach that also considers the floods consequences. Resilience of a RBFM system refers to a systems ability to withstand various precipitation events, reduce flood damage, and restore normal conditions. This study proposes a framework for selecting flood management options in a hierarchical system based on social resilience indicators, focusing on social aspects. In this study, behavior of RBFM systems in response and recovery from varying rainfall events defines the resilience. To operationalize the framework a set of social response, social recovery capacity, resistance point, and warning point-related indicators have been defined. A hierarchical fuzzy system has been developed to quantify the indicators, considering the uncertainties in social variables and avoiding dimensional incosistency. Using this approach in the Gorganrood river basin demonstrated the effectiveness of selected flood risk management options in terms of resilience, by considering various social resilience indicators, as compared with traditional decision-making methods. Comparing the response-recovery curves for different management options has highlighted the importance of defining different resilience indicators to determine the behavior of the RBFM system after performance failure. Finally, the results of this study suggest that the proposed indicators can be employed as decision-making criteria in selecting various management options based on the behavior of the river basin system under rainfall events with different return periods.