Revealing the Impact of Urban Morphology Evolution on the Urban Heat Island Effect in the Main Urban Area of Guangzhou: Insights from Local Climate Zones

Local Climate Zones (LCZs) provide a critical framework for analyzing how urban morphology influences the surface urban heat island (SUHI) effect. However, the spatiotemporal heterogeneity of the driving mechanisms of urban morphology in SUHI within LCZs under urban renewal remains insufficiently understood. In this study, estimated building heights for 2018, 2021, and 2024 in the main urban area of Guangzhou were used to generate LCZ maps using GIS-based methods. Land surface temperatures (LSTs) were retrieved to quantity the SUHI effect. The Geographical-XGBoost (G-XGBoost) model was applied to evaluate the impacts of urban morphology on SUHI. The results indicated the following: (1) Building height estimation errors range from 5.92 to 7.03 m, and incorporating building height data into LCZ classification enabled sensitive detection of urban evolution dynamics. (2) Built LCZ types accounted for the majority of the study area. Between 2018 and 2024, LCZ 3 decreased markedly, by 9.57%, and land cover LCZ types declined annually to 21.35%. (3) Low-level SUHII was predominant, while the proportion of high and extremely high levels of SUHII initially rose before declining to 16.62%. LCZ 2 and LCZ 3 exhibited the highest SUHII. (4) Pervious surface fraction (PSF) is generally regarded as the most important explanatory factor across LCZ types; however, LCZ 4 represents an exception where its importance significantly decreases. This study reveals the nonlinear impacts of urban morphology evolution on SUHI under the effect of the interaction between LCZs and urban renewal, supporting efforts to optimize urban microclimates and promote sustainable development.