Refined urban heat-risk governance zoning in megacities from a social–ecological perspective

With global warming and rapid urbanization, urban heat risk increasingly threatens public health and sustainable urban development. As urban heat risk is jointly shaped by built environments and socio-functional activities, it exhibits coupled social–ecological characteristics. Existing mitigation practices based on administrative units or single zoning schemes often fail to capture intra-urban risk disparities caused by morphology–function interactions. Taking Beijing as the study area, this study develops a fine-scale framework for heat-risk identification and governance zoning from a social–ecological interaction perspective by integrating a hazard–exposure–vulnerability-based heat-risk assessment, Local Climate Zone (LCZ)–Urban Functional Zone (UFZ) interaction units generated through spatial overlay, and block-based governance zoning incorporating LCZ composition, UFZ type, and heat-risk characteristics. The results show that: (1) heat risk in Beijing exhibits a concentric spatial pattern, declining from the central urban area to the periphery, with the risk level in the core area 2.75 times that in the ecological conservation area; (2) heat-risk differences among LCZs within the same UFZ are significant in more than 70% of pairwise comparisons and exceed UFZ-related differences within the same LCZ, indicating that LCZs more frequently differentiated heat-risk conditions within the same functional context; (3) compact high-rise residential areas and commercial and service areas contribute substantially to high heat risk, whereas industrial and transportation zones show marked variation across morphology–function combinations; and (4) based on the block-level mean heat-risk value, UFZ category, and LCZ composition, urban blocks were classified into five primary governance-zone types: commercial and service governance zones, residential governance zones, public administration and service governance zones, industrial governance zones, and transportation governance zones. This study reveals differentiated urban heat-risk patterns driven by the joint effects of urban morphology and function, providing a basis for targeted heat-risk governance and climate-adaptive planning in megacities.