Evaluation analysis and strategy selection in urban flood resilience based on EWM-TOPSIS method and graph model

In the background of rapid population growth and rapid urbanization, extreme floods have brought great challenges to urban construction and development, and have aroused research interest to better understand the role of urban flood resilience (UFR) in mitigating the damage caused by floods. However, most of the existing research on UFR mainly focuses on analyzing the UFR level and its main influencing factors, but rarely involves the strategy selection of stakeholders after evaluation and analysis of UFR. To fill this gap, this study, taking Shanghai as an example, applies the hybrid entropy weight method (EWM)-TOPSIS model to develop an index based measurement to compare and evaluate UFR, and then uses the grey relational analysis (GRA) to find out the main factors affecting UFR. The results showed that the UFR level in Shanghai significantly increased by 39.34% from 2000 to 2020, but the natural resilience showed a fluctuating downward trend. The factors that affect UFR are highly correlated with economic development. The results provide scientific theoretical guidance for the construction of resilient cities. Then, decision makers (DMs) from different departments are involved in the construction and promotion of UFR, and they tend to pay more attention to the factors that are beneficial to them. Based on this, this situation inevitably causes the promotion of UFR in real life to become a conflict problem. Thus, the fuzzy graph model can be used to model and analyze tripartite conflict problems in UFR, and the fuzzy stability analysis represents that state s4 is the optimal solution of conflicts, which can promote each involver to follow the rules and regulations for constructing the UFR for Shanghai in spirit.