A supply-demand model of vegetation cooling for urban heatwave mitigation

The tradeoff between heatwave-induced human health risks and vegetation heat mitigation benefits is critical for mitigating heatwave hazards in urban regions. Currently, the heat risk study often focuses on the severity of heat risk to human health while the vegetation cooling is often ignored. Here, we proposed a new supply-demand matching model combining the vegetation cooling supply with the cooling demand induced by the high temperature. The cooling demand was assessed based on a heat exposure, population exposure, and heat vulnerability. The vegetation cooling supply was calculated by using a remote sensing-driven evapotranspiration (ET) model. Results showed: (1) The supply-demand matching model can identify cooling supply-demand mismatch zones in urban areas. (2) The vegetation ET model based on remote sensing can better represent the cooling benefits of vegetation compared to the vegetation abundance such as NDVI; (3) There was a special cluster of heat risk and cooling supply-demand mismatch in blocks of Beijing. The cooling supply and demand comparison model can inform vegetation-based intervention measures and urban planning guidelines for heat risk management.