Morphological Spatial Clustering of High-density Central Areas and Their Coupling Relationship with Thermal Environment——A Case Study of the Wuyi Road Hatchback in Changsha

Abstract Intense urban development and high urban density cause the thermal environment in urban centers to deteriorate continuously, affecting the living environment quality. In this study, 707.49 hectares of land in the central area of Changsha were divided into 121 plots. 11 microclimate-related morphological indicators were comprehensively selected, and the K-means method was used to cluster the plots. Then, the relationship between morphological clusters and the thermal environment was explored by simulating the thermal environment of the study area using Envi-met. First, five spatial types were found to characterize the area: High-rise-High-volume-Low-density-Low-green; Middle-rise-High-volume-High-density-Low-green; Low-rise-Low-volume-High-green; Medium-volume-High-density-Low-green; and Low-rise-Low-volume-Low-density-High-green. Second, the Sky View Factor, the Area-weighted Building Shape Index, the Building Windward-surface Density, the Building Density, and the Building Average Volume significantly affect the thermal environment. Third, Cluster 3 had the highest average air temperature (Ta), followed by Clusters 2 and 1, and Clusters 4 and 5 had relatively low Ta. The spatial vitality index and building otherness in Cluster 1; the area-weighted building shape index and average building volume in Cluster 2; green space coverage in Cluster 3; floor area ratio in Cluster 4; spatial vitality index, building average volume, and height in Cluster 5 had greater influences on Ta. Fourthly, simply increasing the area of green space cannot maximize the cooling effect of green spaces. Instead, constructing an equalized greening network can better regulate the thermal environment. Fifthly, the results provides a scientific basis for the design and the regulation of urban centers.