Spatially explicit assessment of the heat-related health risk in the Yangtze River Delta, China, using multisource remote sensing and socioeconomic data

Abstract

With frequent extreme heat events (EHEs), rapid urbanization, and uneven social development, comprehensive assessment of heat-related health risks is important for tolerating hot weather. This paper proposed a quantitative method for assessing heat-related health risks at the grid scale. A combination of multisource remote sensing and socio-economic data was utilized to develop an integrated heat health risk index (HRI) considering three dimensions of heat hazards, exposure, and vulnerability in the Yangtze River Delta (YRD), China. Compensating for the limitations of land surface temperature (LST) and station data, daily air temperatures were retrieved to calculate heat hazard index. Gridded population density data were developed using nighttime light data to calculate the exposure index. By combining them and other indicators, an HRI map of the YRD was developed. Furthermore, the spatial heterogeneity and dominant factors of the heat health risk were examined. The results showed that 13.2 % of the areas in the YRD were in high and medium high risk, while 58.6 % were in low and medium low risk. The high-risk areas were primarily concentrated in the Shanghai-Hangzhou Bay urban agglomeration, suggesting synergy between increased exposure and hazards in these metropolitan areas. The high-risk areas were predominantly dominated by hazard/exposure (H-E) and exposure/vulnerability (E-V), accounting for 27.2 % and 21.9 % of the YRD's total area respectively. This study contributes to the identification of areas vulnerable to heat stress and provides references for optimizing heat risk management strategies.