Supply and demand analysis of urban thermal environments regulation services from an accessibility perspective: A coupled thermal risk and green space cooling assessment model

Urban Green Spaces (UGS) play a pivotal role in regulating the urban thermal environment, but the balance between the supply and demand for hot and cold spaces is often mismatched, leaving high-risk areas with inadequate cooling services. Oreover, due to population mobility and the complexity of spatial structures, the radiative effects between hot and cold spaces are often insufficiently considered. Therefore, this study proposed an accessibility-based framework for thermal environment assessment, which integrates thermal risks with the cooling benefits of green spaces, offering a comprehensive evaluation of urban heat conditions. Taking the central urban area of Fuzhou as a case study, the results demonstrate that Fuzhou's thermal environment risks are significant and worsening, with areas at level 4 and level 5 risk constituting 36.42 % of the city. The exposure to thermal risks has also increased, with high-exposure risk areas in 2023 rising by 4.67 % compared to 2008. In addition, the cooling service capacity has decreased, but overall cooling service accessibility is largely unaffected. In terms of the interaction between heat exposure and cooling accessibility, there is a significant spatial development inequality within the central city. This study provides a scientific basis for improving the urban thermal environment by identifying these problem areas and proposing appropriate spatial development strategies.