Research on the Resilience and Impact Mechanism of Urban waterlogging in the Chengdu Chongqing Economic Circle Urban Agglomeration

Urban waterlogging resilience is one of the core indicators of urban sustainable development. This study is based on sample data from 16 prefecture-level cities within the Chengdu-Chongqing Economic Circle urban agglomeration from 2000 to 2023. Using ArcGIS and other software tools, the study employs methods such as the entropy weight method, the PSR model, and the spatial Durbin model to empirically analyze the spatiotemporal evolution and impact mechanisms of urban waterlogging resilience. The findings reveal the following: (1) From 2000 to 2023, the average resilience of urban agglomerations to waterlogging increased from 0.158 to 0.525, exhibiting a general upward trend characterized by "stable fluctuations and high-speed growth". Chengdu experienced the most significant increase, rising by a factor of 3.25, while Ya'an saw the smallest increase, with a factor of 1.07. (2) The resilience of urban waterlogging within the Chengdu-Chongqing Economic Circle exhibits a spatial pattern of "high in the east and west, low in the center". Both Chengdu and Chongqing have consistently remained in high-resilience areas, with surrounding cities gradually showing clustering trends. (3) The analysis of the driving mechanism reveals that per capita GDP exhibits a negative spillover effect, known as the "siphon effect," in economically adjacent areas, while the road network and drainage network show a positive synergistic effect; The monthly average rainfall generates a positive local effect by forcing facility upgrades; The effect of urban green space ratio and drainage network coefficient is constrained by spatial correlation and extreme scenarios. Based on this, the study proposes a path to strengthen the coupling of grey and green facilities and cross regional collaborative governance, providing theoretical support and scientific basis for the collaborative governance and resilience improvement of waterlogging in the Chengdu Chongqing urban agglomeration.