Spatiotemporal Evolution of Urban Heat Islands and Optimization of Spatial Network Construction in the Central Urban Area of Fuzhou City, China

Although accelerated urbanization has led to economic prosperity, it has also resulted in urban heat island effects. Therefore, identifying methods of using limited urban spaces to alleviate heat islands has become an urgent issue. In this study, we assessed the spatiotemporal evolution of urban heat islands within the central urban area of Fuzhou City, China from 2010 to 2019. This assessment was based on a morphological spatial pattern analysis (MSPA) model and an urban thermal environment spatial network constructed using the minimum cumulative resistance (MCR) model. Optimization measures for the spatial network were proposed to provide a theoretical basis for alleviating urban heat islands. The results show that the heat island area within the study area gradually increased while that of urban cold island area gradually decreased. The core area was the largest of the urban heat island patch landscape elements with a significant impact on other landscape elements, and represented an important factor underlying urban heat island network stability. The thermal environment network revealed a total of 197 thermal environment corridors and 93 heat island sources. These locations were then optimized according to the current land use, which maximized the potential of 1599.83 ha. Optimization based on current land use led to an increase in climate resilience, with effective measures showing reduction in thermal environment spatial network structure and function, contributing to the mitigation of urban heat island. These findings support the use of current land use patterns during urban heat island mitigation measure planning, thus providing an important reference basis for alleviating urban heat island effects.