Revealing the impacts of 3D urban morphology on surface temperature considering geometry heterogeneity, component contribution, and scale effect

Abstract

3D urban morphology profoundly alters the urban thermal environment by reshaping the local heat flux and surface energy balance. However, the impacts of geometry heterogeneity of buildings, component contribution, and scale effect of 3D urban morphology on surface temperature remain largely unknown. To address these issues, this study employed ENVI-met to simulated the thermal environment of 117 heterogenous urban scenes and estimated the impacts of 3D urban morphology indicators. These scenes were parametrically generated with a range of building height (BH), size (BS) and interval (BI) in order to construct a controllable and heterogenous sample set of 3D urban morphology. The results indicate that (1) Sky view factor (SVF), aspect ratio (AR), and floor area ratio (FAR) cause smaller building geometry heterogeneity losses than other indicators at a fine scale; (2) The contribution of 3D urban morphology indicators to the floor, wall and roof temperature differs, with a ratio of about 43.84 %, 49.01 %, 7.15 %; (3) Scale effect significantly affect the contribution of urban 3D morphological indicators to surface temperature, yet exert minimal influence on the performance in characterizing building geometry. These results reveal the interaction regularity between 3D urban morphology and surface temperature, and provide a valuable reference for multi-scale simulation of urban surface temperature.