Spatiotemporal Evolution and Driving Mechanisms of Urban Ecological Resilience in Southwest China: A Dual Framework of SDM and XGBoost–SHAP

Ecological resilience represents a region's fundamental capacity to withstand external disturbances and achieve sustainable development. As a typical ecologically fragile region in China and globally, Southwest China warrants particular attention in terms of understanding the spatiotemporal evolution and driving mechanisms of ecological resilience. Taking 47 cities in Southwest China as the study area,this study constructs an urban ecological resilience evaluation index system based on the "Pressure–State–Response–Innovation" framework. By integrating centroid migration analysis, standard deviation ellipse analysis, kernel density estimation, spatial autocorrelation analysis, the Spatial Durbin Model (SDM), and the XGBoost-SHAP model, the spatiotemporal evolution and driving factors of urban ecological resilience from 2005 to 2024 are systematically examined.The results indicate that: (1) During the study period, disparities in urban ecological resilience across Southwest China gradually widened, accompanied by pronounced regional differentiation. Kernel density estimation further reveals a clear polarization trend in urban ecological resilience. (2) The SDM results demonstrate that urban ecological resilience exhibits strong spatial dependence. For most driving factors, the indirect effects exceed the direct effects, suggesting that their influences are primarily transmitted through spatial spillover mechanisms. (3) The XGBoost-SHAP results reveal significant local threshold effects and interactive relationships among the driving factors of ecological resilience. (4) Significant interprovincial heterogeneity exists in the driving mechanisms of ecological resilience. These findings enrich the analytical framework for urban ecological resilience research and provide important scientific support for differentiated ecological governance and high-quality sustainable development in ecologically fragile regions.