The Research on National Heat Vulnerability Assessment of China

Abstract

Background: At present, many countries and regions have conducted heat vulnerability assessment studies to effectively identify vulnerable areas and populations. In China, heat vulnerability assessments have been conducted in some areas, but there is a lack of coverage across many parts of the country. The impacts of heat vulnerability are still unknown for most areas in China. Objectives: We aim to establish a preliminary heat vulnerability index system in China. Based on the establishment of a nationwide county-scale heat vulnerability index, we assessed the spatial distribution of heat vulnerability in China. Methods: We used principal component analysis to reduce the dimension of heat vulnerability indicators. The heat vulnerability index of each county was calculated by a summation of the principal component scores of the corresponding districts and counties. In order to better intuitively understand the distribution of China's heat vulnerability index, we displayed the results of the index on a spatial map. Results: The average value of the heat vulnerability index is 13.84, with a median of 14, and a standard deviation of 1.77. The high vulnerability areas, defined with a heat vulnerability index value of16-22, include a total of 394 counties/districts. Low vulnerability areas, defined with a heat vulnerability index value of 5-13,include a total of 1061 counties/districts. The spatial pattern map of the heat vulnerability index indicates that there are many areas with low heat vulnerability in the southeastern coastal areas and central regions, and there are many areas with high heat vulnerability in the northeast and western regions. Conclusion: Geographic, urbanization, economic, and health factors are the primary influencing factors of China's heat vulnerability. Low-income groups, low-education groups, ethnic minorities, and the elderly are particularly vulnerable to the effects of heat in China.