Demand of urban green space cool islands based on heat island pattern: A case study of Chaoyang District of Beijing

Abstract

Urban green space is often used as an effective measure to mitigate urban heat island (UHI) effect through their cooling effect. Although abundant studies have observed the cool island phenomenon of urban green space, few studies estimated cool island demand in the context of urban heat island. This study built an empirical model of cool island demand on the basis of urban heat island spatial pattern, and estimated the demand level and configuration requirement of green space for UHI mitigation. The results indicate that in 2017, there existed about 6522 hm2 of heat islands with land surface temperature exceeding 40℃ in Chaoyang District. The number of urban heat island patches reached 619, concentrated in the southern part of Chaoyang District. The area of heat islands greatly increased from the western to the eastern part of the city. Approximately 6154 hm2 of cool islands were needed for the mitigation of the urban heat island effect. The area of high demand region for cool islands was 1054 hm2, distributed in Balizhuang of Chaoyang District. The moderate demand region reached 2021 hm2, located in Shuangjing, Jinsong, and Panjiayuan. The remaining 3079 hm2 belonged to the low demand region for cool islands, scattered in the district. In planned ecological land, urban green space cool island demand region should meet the requirement of greening area, community structure, and vegetation configuration, whereas the cool island demand area in the planned construction land should improve and utilize the cooling effect of adjacent green spaces.