Association between Three-Dimensional Built Environment and Urban Air Temperature: Seasonal and Temporal Differences

Climate change and the urban heat island phenomenon are increasingly important issues in urban thermal environments. However, there is a lack of research on the relationship between three-dimensional built environments and air temperature. Therefore, the purpose of this study is to provide policy suggestions that could be used to improve urban thermal environments by analyzing the effect of the three-dimensional built environment of an urban space on the urban air temperature according to changes in time (i.e., season, time of day). Using data from 236 automatic weather stations (AWSs) in Seoul, Korea, this study focused on three-dimensional built environmental variables and land use variables that affect air temperature in terms of season and time. The analysis results indicate that the sky view factor and porosity were lower in urban areas, with higher sky view factor and porosity values associated with lower air temperature. This study also indicates that surface roughness is higher in urban areas, with higher surface roughness associated with higher air temperature. These results suggest that urban design practices should consider the three-dimensional built environment when planning urban development and urban regeneration projects in order to improve the urban thermal environment.