Spatiotemporal differentiation and influencing factors of urban water supply system resilience in the Yangtze River Delta urban agglomeration

Because of the ever-increasing impact of climate change and human activities, urban water supply systems encounter multifaceted challenges in providing sustainable services under various uncertainties. Urban water supply system resilience (UWSSR) refers to the ability of a water supply system to maintain its functional stability and adapt to changes. This study aims to analyze the spatial and temporal differences of UWSSR characteristics in the Yangtze River Delta urban agglomeration of China, as well as the contributing factors. Twelve indicators are selected to establish the evaluation framework, and the composite index is calculated using the coefficient of variation method. The spatial agglomeration and distribution characteristics are discussed based on spatial correlation analysis. The results show that (i) UWSSR does not improve significantly with time because it is mainly constrained by the extent of water resources. (ii) UWSSR has a significant spatial correlation for most years, but the spatial agglomeration pattern is not significant. (iii) UWSSR is positively influenced by public services and negatively influenced by public regulation and the level of urbanization during two successive stages. The variables whose regression coefficients changed during these stages are per capita gross domestic product, public financial resources, level of industrialization, public investment in water supply facilities, and public investment in science and technology. This means that the impact of these variables on resilience inverted from promotion to inhibition or from inhibition to promotion. Therefore, this study provides a reliable framework to evaluate the status of UWSSR and its driving factors, which can support effective management practices.