Prefecture-level health risk assessment for hot extremes in China

Evaluating prefecture-level health risks for hot extremes is the core of localized adaptation measures to mitigate negative heat-related impacts. Here, by applying the heat hazard-human exposure-social vulnerability framework, we assessed the prefecture-level health risk for summertime hot extremes in China, with multisource data from 329 prefecture units. Regions suffering very high and high levels of health risk were observed in several main basins and plains, including the Turpan Basin, the North China Plain, the middle-lower Yangtze River Plain, the Pearl River Delta, the Chengdu Plain, and the Wei River Valley. Health risk structures were identified, and 72 prefecture units (22%) were found in the risk zone of Hh-He-Hv (high heat hazard, high human exposure, and high social vulnerability), of which 44% of sites were distributed in the North China Plain and must be prioritized for adaptation. The risk components of human exposure were the main drivers of health risk and its spatial heterogeneity. For the southeastern region, social vulnerability plays a more significant role than heat hazard. Four types of social vulnerability were summarized and will be useful for targeted adaptation plans. The assessment process will be insightful and can be applied in other countries or on a global scale.