Exploring the spatiotemporal evolution patterns of Urban Heat Island with a network-based approach

Exploring the development patterns of surface urban heat island (SUHI) has become crucial for formulating corresponding excess heat mitigation measures. However, there is currently a lack of analysis on the importance and interactions of different SUHI patches. This paper proposes a simple and effective method for measuring SUHI patterns, revealing the development patterns and growth trends of SUHI through spatial integration and interaction network construction. The results show that the values of nodes and edges in the SUHI network have continuously increased from 2005 to 2020, with an increase of the average importance index of nodes and the average interaction intensity of edges in the three regions by 40.2% and 23.6%, respectively. Moreover, the development pattern of SUHI exhibits a distinct unimodal characteristic. When the merging speed of SUHI patches exceeds the speed of new patch emergence, the total number of patches will decrease. The method proposed in this study demonstrates strong applicability across the three urban agglomerations and can be extended to other regions. The SUHI network enables the practical and efficient excess heat mitigation of heat island effects through the management (disruption) of key nodes. The corresponding heat island development hypothesis also enriches the theoretical understanding of heat island development.