Green space configuration strategies shape heat exposure mitigation patterns in Chinese cities

Climate change and urbanization have exacerbated extreme heat events, increasing the risk of heat exposure among urban residents. Urban vegetation is widely recognized as an important nature-based solution for mitigating urban warming and reducing heat risk. However, the heat exposure mitigation potential of different green space configuration strategies and their spatial heterogeneity across diverse urban environments remain insufficiently evaluated. This study systematically analyzed the spatiotemporal evolution and scale-dependent variations in vegetation and heat exposure across 303 Chinese cities from 2000 to 2024, and quantitatively evaluated the mitigation potential of four green space configuration strategies for urban heat exposure under a unified greening increment constraint by developing a temperature-based urban heat exposure assessment framework. The results indicate that urban vegetation dynamics and high-temperature evolution in China exhibit significant spatiotemporal heterogeneity, with high-density urban agglomerations showing higher heat exposure intensity and stronger spatial clustering. Under a unified greening increment constraint, different green space configuration strategies reduce population-weighted heat exposure by 5.4%–18.3%. The mitigation effects not only exhibit a stable performance gradient but also shift high-mitigation areas from a locally dispersed pattern to clustering within urban agglomerations. This study reveals differences in heat exposure mitigation among various green space configuration strategies, providing quantitative evidence for urban green space optimization and climate adaptation under resource constraints.