Key areas and measures to mitigate heat exposure risk in highly urbanized city: A case study of Beijing, China

As an effective measure to mitigate the negative effects of heat-related risks on human health, improving the urban environment requires space and financial resources. It is necessary to identify the key areas to mitigate heat-related risk to balance mitigation efficiency and planning feasibility. This study proposes a framework to identify key areas from a network perspective based on heat exposure risk identification and green infrastructure construction. Two networks, a heat exposure spreading network and a green infrastructure network, were constructed using morphological spatial pattern analysis and circuit theory based on population density and remote sensing image data. Beijing, as a highly urbanized city, was chosen as the case study. For key areas, we proposed environmental improvement measures, and the effectiveness of these measures was confirmed by ENVI-met simulations. The results show that there are 294 key areas that could split high heat exposure patches, block high heat exposure patch connections, and control the spread of high heat exposure patches. Increasing greenery coverage by increasing street tree greening, parking lot greening, urban forest construction, and urban park construction can reduce regional temperatures by 0.18-5.34 degrees C. This study provides an approach to mitigate heat-related risk in highly urbanized cities.