Urbanization induced Urban Canopy Parameters enhance the heatwave intensity: A case study of Beijing

Abstract

Urban morphology, characterized by Urban Canopy Parameters (UCPs), significantly impacts the local climate. Presently, due to the absence of long-term UCP datasets, their effects on urban climate modeling have not been comprehensively analyzed, especially under a complicated urbanization background. Therefore, we developed a dataset of UCPs for Beijing from 1985 to 2023 annually to characterize the spatial heterogeneity of urban land surface induced by urbanization. After that, using the Weather Research and Forecasting coupled with single layer urban canopy model (WRF-SLUCM), we conducted high-resolution numerical simulations with different UCPs under diverse urbanization stages (UCP1985 and UCP2023) in Beijing during a heatwave episode in June 2023. The developed UCPs indicated significant spatiotemporal changes in Beijing's urban morphology, particularly in the suburbs. Different UCPs were associated with distinct trends, while there were strong positive correlations between UCPs with similar physical meanings. Additionally, the simulation results of the WRF model with UCP2023 showed that the average temperature increased 3.10 °C at nighttime, compared to UCP1985. Meanwhile, the phenomenon of warming in suburban was more significant than in urban and rural regions. The variations in 3D characteristics of urban morphology played an important role in clearly depicting the urban thermal environment. Our results offer a new approach to revealing the nexus between urban morphology and urban climate, showing great potential to promote sustainable urban planning and management.