Spatiotemporal evolution patterns of urban heat island and its relationship with urbanization in Guangdong-Hong Kong-Macao greater bay area of China from 2000 to 2020

The unprecedented wave of urbanization has led to the development of the urban heat island (UHI) effect in the Guangdong-Hong Kong-Macao greater bay area (GBA) of China. In this study, the spatiotemporal evolution patterns of UHI and its relationship with the urban expansion of the GBA from 2000 to 2020 were explored. First, the space–time cube model and emerging hot spot analysis were applied to identify the spatiotemporal patterns of UHIs. Second, centroid movement analysis, spatial coupling analysis, and a geographical detector model were applied to quantify the relationship between UHIs and urban expansion. Results found that urban expansion was strongly influenced and highly coupled with the UHI change in the GBA. The main hot spot patterns, intensifying hot spot, persistent hot spot, and sporadic hot spot were distributed in the GBA center. Importantly, three intensifying hot spot areas were detected at the junctions of several major cities, where the increases in land surface temperature and urban expansion were spatially consistent. It is recommended that urban planning should consider the fragile thermal environment in highly urbanized areas. This study provides a novel spatiotemporal analytical framework for monitoring the long-time series of changes in the surface environment of cities.