Urban Flood Resilience Assessment of Prefecture-Level Cities in Yangtze River Delta

The frequent occurrence of flooding disasters threatens urban public safety and sustainable development, making enhancing urban ecological resilience crucial for flood prevention and disaster reduction. This study, focusing on the Yangtze River Delta urban agglomeration (YRD) in China, constructs an evaluation framework based on three subsystems: the hazard, disaster-formative environment, and exposure. Using the entropy weight method, Geographic Information Systems (GIS), along with spatial autocorrelation analysis, the spatial distribution and trend of resilience indices are obtained. Based on stepwise regression analysis, the factors influencing the resilience distribution are discussed. The results show an overall increase in resilience levels in the YRD urban agglomeration, reflecting improvements in the urban emergency response and recovery capabilities. However, significant differences exist between cities, with a trend of decreasing resilience from first-tier cities to surrounding areas. Among these, indicators such as per capita disposable income and the number of people covered by social insurance have a significant positive impact on resilience clustering, highlighting the key role of socioeconomic vitality in urban resilience. This study is of great significance for differentiated and scientific flood disaster management in urban agglomerations.