A coupled heat–cold island network framework for urban heat island mitigation: a case study of Central Fuzhou

With the acceleration of global warming and urbanization, the urban heat island (UHI) effect has become a significant environmental problem affecting urban ecological security and residents' health. Current research primarily focuses on the independent effects of single cold or heat island systems, and strategies for mitigating the regional heat island effect remain incomplete. This study takes the central urban area of Fuzhou City as the research object and constructs a comprehensive analytical framework integrating the Patch-generating Land Use Simulation Model (PLUS), Morphological Spatial Pattern Analysis (MSPA) landscape pattern analysis, and Circuit Theory (CT). The results show that the area of high-temperature zones in the central urban area of Fuzhou City increased significantly from 2012 to 2022, while the area of cold islands continued to decrease significantly. The PLUS model predicts that the high-temperature zone will further spread outwards by 2027. 23 cold island sources and 14 heat island sources were identified, forming 57 cold island corridors and 30 heat island corridors. Furthermore, 32 cold island bottlenecks and 12 heat island bottlenecks, as well as 18 cold island barriers and 10 heat island barriers, were identified, clarifying the core role of key nodes in the conduction of cold and heat energy. Based on this, a collaborative strategy of "cold island protection-heat island blocking-cold and heat reconstruction" is proposed, constructing a multi-level temperature regulation system through the combined action of ecological corridors and regulating corridors. This study provides a new scientific path for mitigating the urban heat island effect and has important theoretical and practical significance for optimizing urban planning.