The Urban Heat Island (UHI) effect poses a major challenge to climate adaptation in urban agglomerations. Most studies evaluate Surface Urban Heat Island Intensity (SUHII) within predefined extents, overlooking how management boundary delineation can guide mitigation across jurisdictions. This study proposes a UHI management boundary framework that integrates disaster risk and governance conditions, grounded in a multidimensional SUHII assessment, and applies it to China’s Guangdong-Hong Kong-Macao Greater Bay Area (GBA). An exponential decay model was employed to identify SUHII change points and track SUHII dynamics from 2010 to 2020, considering diurnal, anthropogenic, and natural factors. Results show a clear core-to-periphery decline, with stronger SUHII during the daytime than at nighttime, on weekdays than weekends, and in rainy months than in non-rainy months. A disaster risk index incorporating heat source and heat sensitivity indicators and a governance condition index covering ecological and social indicators was then constructed and coupled with SUHII. Composite rankings were used to delineate management zones, identifying 15 Priority, 23 Key, and 38 General Management zones. By moving beyond SUHII single-dimensional delineation, the framework highlights risk-condition synergy and provides spatiotemporal evidence to support coordinated climate action in urban agglomerations. The approach is scalable and can inform governance strategies worldwide.
Cai et al. (Sun,) studied this question.