Exploring the seasonal effects of urban morphology on land surface temperature in urban functional zones

Rapid urbanization intensifies the urban heat island (UHI) effect, leading to a multitude of urban challenges. It is important to conduct comprehensive research to understand the underlying mechanisms driving the UHI. Although previous studies have identified the significance of the effects of urban morphology on land surface temperature (LST), the variations in its effects on LST across seasons and different types of urban functional zone (UFZ) remains undefined. Therefore, we explored the seasonal effects of urban morphology, including landscape indicators, building morphology, and surface biophysical parameters, on LST in different types of UFZ by random forest (RF) regression model. Taking the central urban area of Guangzhou as an example, the results indicated that the impacts of urban morphology on LST were strongly dependent on the seasons and UFZs types. The effects of urban morphology on LST were similar across spring, autumn, and winter, with the building morphology showing substantial impacts in commercial and residential zones. In summer, the effects of surface biophysical parameters on LST were significant, especially in industrial, residential, and public service zones. In addition, warming and cooling factors varied across seasons and UFZs. Vegetation was the effective cooling factor during summer, with its fragmented and irregular distribution making a prominent cooling effect in commercial and residential zones, and its coverage crucial for reducing LST in industrial and public service zones. Building height was the dominant cooling factor in spring, autumn, and winter. We consider that these findings can enhance our understanding of the driving mechanism of UHI effect and offer precise references for urban planning in different seasons and UFZs to effectively mitigate the UHI effect.