Study On Population Health Risk Pattern And Future Trends Under Extreme Heat Stress In China

With global warming,extreme heat events frequently occur,and heat waves have had a significant impact on socio-economic development and population health,and have become one of the hot issues studied by scholars at home and abroad.Explore population health risks under extreme heat stress and their spatial distribution characteristics,and reasonably distinguish the dominant types of risk areas.At the same time,under the trend of future climate change,it can prevent high-temperature disasters,reduce the health risks of hightemperature populations,and improve the adaptability of social climate change to propose effective countermeasures.Through the disaster concept of “Extreme Heat DisasterPopulation Exposure-Vulnerability”,an analysis framework for the health risks of the extreme heat population is constructed,which provides a theoretical basis for the formulation of prevention and control plans in response to the risks brought by extreme heat to population health.This paper uses the daily maximum temperature,census data,and kilometer GDP data to analyze the temporal changes of extreme heat characteristics,extreme heat stress index,extreme heat population vulnerability,and extreme heat population health risk spatial distribution pattern of China's 2 km×2 km grid scale from 1961 to 2018,and divide the dominant type area.Using RCPs scenarios and GCM models,this paper predicted the spatiotemporal changes of China's extreme heat index in the future,combined with economic and population data in 2050 and 2100 under the SSPs path to predict the future spatial distribution pattern of extreme heat population health risks and divide the dominant types of regions.The main conclusions of this article are as follows:(1)From 1961 to 2018,extreme heat and heat wave events mainly occurred in southern China,especially in the southern and western regions of East China,while the north only occurred in Xinjiang.However,the extreme heat intensity in the north is much higher than the extreme heat intensity in the south.(2)From 1961 to 2018,the area where extreme heat caused harm to population health accounted for a relatively high proportion,and there was obvious spatial heterogeneity in the distribution characteristics.(1)The areas with high heat stress index accounted for 20.04%of the country's area,mainly distributed in the central and southern regions of China.In 2018,the population proportion and economic proportion of China's extreme heat stress index high-risk areas were 20.64% and 19.73% respectively;(2)The vulnerability of the extreme heat population gradually decreased from the southeast to the northwest,and the extreme heat population vulnerability index was higher and highest.Distributed in the central and southeast coastal areas of China.(3)The extreme heat population's health risk gradually decreases from the southeast to the northwest.The high-risk areas are mainly distributed in southern North China,Central China,Guanzhong,Urumqi,Xinjiang,and Liaoning,Shenyang,and Heilongjiang in the northeast.(4)The dominant population exposure areas are located in the central and southeast coastal areas of China and Urumqi,Xinjiang;the extreme heat stress areas are located at the junction of Sichuan and Chongqing,Hunan Province,the northwestern part of Jiangxi and Zhejiang;the vulnerable areas are located in the Pearl River Delta And the Yangtze River Delta region;while the extreme heat-vulnerability dominant area does not show the characteristics of agglomeration spatial distribution.(3)In the prediction of the extreme heat stress index under different scenarios,the proportion of the area of the extreme heat stress index above level 4 is ranked as follows: in 2050,RCP8.5(4.85%)> RCP4.5(3.90%)>RCP2.6(2.86%);In 2100,RCP8.5(15.52%)> RCP4.5(8.46%)> RCP2.6(4.48%),of which the area where the extreme heat stress index is at level5 under the RCP8.5 scenario is 2.2 times of the RCP4.5 scenario and 4.3 times of the RCP2.6scenario.(4)There are obvious temporal and spatial differences in the evolution of extreme heat population health risks under different scenarios.(1)In the RCP2.6?SSPs scenario combination,in 2050,China's extreme heat population health risk areas will be located in Henan Province;in 2100,China's extreme heat population health risk areas will be located in Henan,Anhui,southern Hebei,and Shandong Western and other regions.(2)In the RCP4.5?SSPs scenario combination,in 2050,extreme heat population health risk areas in China will be distributed in Henan and parts of Shanghai;in 2100,extreme heat population health risk areas in China will be distributed in Henan,Hubei,and Anhui,Southern Hebei,Western Shandong and other regions.(3)In the RCP8.5?SSPs scenario combination,in 2050,extreme heat population health risk areas in China will be distributed in Henan and parts of Shanghai;in 2100,China's extreme heat population health risk areas will be concentrated in Henan,Hubei,Anhui,southern Hebei,western Shandong,Guangdong and Guangxi.(5)The area of the dominant population exposure area is larger than other dominant types,mainly distributed in North China,Central China,Eastern and Western China,and northern Guangzhou.The dominant area of extreme heat stress is mainly distributed in central China.The vulnerable areas are distributed in northwestern Henan,Tianjin,and parts of Guangzhou.The dominant areas of extreme heat-vulnerability comprehensive influence are mainly distributed in parts of northwestern and southern parts of Henan.Among them,in the RCP8.5?SSPs scenario combination,the future high temperature population has the largest health risk area.(6)Responding to the risk of high temperature disasters should start from the perspective of mitigating high temperature heat waves and reducing the health risks of high temperature populations.Measures to alleviate high temperature and heat wave disasters are proposed at three levels: national policies,regional measures,and urban internal construction;to reduce the health risks of extreme heat populations,recommendations are mainly made from the three dimensions of extreme heat stress,vulnerability and population exposure.