Spatial mismatch between heat exposure and cooling accessibility in the Middle Yangtze River Urban Agglomeration

Abstract

Abstract Urban heat risk is shaped not only by thermal intensity but also by whether cooling resources are spatially aligned with populations experiencing greater heat exposure. This study developed a spatial diagnostic framework to identify heat exposure–cooling accessibility mismatch across the built-up areas of 30 cities in the Middle Yangtze River Urban Agglomeration, China. Potential heat exposure was characterized using land surface temperature and population density, while potential cooling accessibility was quantified using a two-step floating catchment area method based on urban parks and water bodies. The results revealed pronounced spatial mismatch between heat exposure and cooling accessibility. High-exposure and low-accessibility areas were concentrated mainly in dense urban cores and transitional development zones, whereas higher cooling accessibility occurred more frequently near peripheral or waterfront blue–green resources. Cities with greater mean cooling accessibility did not necessarily exhibit more equitable spatial distributions, demonstrating that spatial configuration and proximity were as important as resource quantity. A leakage-controlled Random Forest (RF) model achieved an AUC of 0.747, while city-group cross-validation yielded a mean AUC of 0.744, indicating moderate and relatively stable cross-city discrimination. SHAP analysis identified impervious surface ratio, building density, and green-space ratio as the principal environmental predictors associated with mismatch probability. Priority screening further identified Level I and II zones covering 19.03% of the built-up analytical area, where high mismatch probability, limited cooling accessibility, and age-related vulnerability jointly occurred. The framework provides a potentially transferable approach for diagnosing exposure–cooling service mismatch and supporting context-specific urban climate adaptation planning.