Construction of an Urban Cold Island Network Incorporating Three-Dimensional Building Morphology and the Local Wind Environment: A Case Study of the Central Urban Area of Hefei

Urban heat islands (UHIs)—one of the most severe environmental side effects of urbanization—can be effectively alleviated by blue–green spaces, whose shading and evaporative cooling generate localized cool islands with well-documented effectiveness. Taking the central urban area of Hefei as the study area, this study identified cold island core sources, cold island corridors, and cooling and heating nodes. The results indicated that: (1) the central and southern parts of the study area exhibited the highest building density and the most pronounced UHI effect; (2) 133 cold island core sources, totaling 196.36 km2 and accounting for 22% of the study area, were identified through morphological spatial pattern analysis (MSPA); and (3) 145 cold island corridors, 112 cooling nodes, and 23 heating nodes, together with the five areas of cooling-heating node overlap, were extracted using the Linkage Mapper toolbox to construct the cold island network. This network can provide a scientific basis for urban blue–green space planning and ventilation corridor regulation, and offers a transferable technical framework for UHI mitigation in comparable rapidly urbanizing regions.