Regulation on air temperature by residential area morphology: A case study in Xuzhou City, China.

Due to woodlands and farmlands being replaced by residential areas in cities, continuous urbanization resulting in frequent urban heat island effects, especially in summer when high temperature seriously threaten health and lives of citizens. Although scientists realized that reasonable residential area morphology could effectively regulate air temperature and improve microclimate, it is lack of air temperature regulation-oriented specifications and requirements on morphology of residential areas. In this study, we used three types of morphological parameters of 15 residential areas in Xuzhou City and air temperature data via field investigation to analyze air temperature regulation caused by residential area morphology. The results showed that key morphological parameters of residential areas were different in morning and afternoon. In morning, independent effects of mean building height, street aspect ratio, and complete aspect ratio contributed 15.4%, 7.3%, and 6.8%, while those of building density, sky view factor, and the ratio of building surface area to floor area were 21.1%, 23.1%, and 6.9% in afternoon, respectively. Threshold values of efficiency of morphological parameters of residential areas were different between morning and afternoon. There were significant correlations between some morphological parameters of residential area. The results could provide data support and methodological reference for residential areas design in Xuzhou and surrounding cities.