Research On Risk Assessment Of Extreme High Temperature Disasters In China

In recent years,Working Group I(WG I)and Working Group II(WG II)of the Sixth Assessment Report on Climate Change(AR6)of the United Nations Intergovernmental Panel on Climate Change(IPCC)have successively pointed out that the global trend of obvious warming and a significant increase in the intensity and frequency of high temperature are widely affecting nature and human society,leading to losses and damages and posing serious and irreversible risks.In order to clarify the changing characteristics of high temperature risk,this paper analyzes the high temperature risk in China and the degree of influence of its internal factors based on meteorological data,demographic data,and socioeconomic data,using the high temperature risk evaluation index system and evaluation model and risk contribution model,and clarifies the risk-causing types at the municipal scale in China.The GFDL-ESM4 model is also used to make scenario predictions of China’s future high temperature risk.The results of the study are as follows.(1)From 1961 to 2020,the intensity of high temperature and the number of high temperature days in China showed a fluctuating upward trend,with the most obvious performance in the southeast and northwest;the city with the highest risk was Turpan City(0.5),the city with the highest exposure was Shenzhen City(1),and the city with the highest vulnerability was Dalian City(1.87).The high temperature risk distribution in China has obvious clustering characteristics,and the high-risk areas are mainly distributed in the southeast and northwest regions of China,and the urban high temperature risk values are located between 0.00 and 0.50,among which Yuxi,Turpan,Hangzhou,and Nanchang have higher high temperature risks;hazard makes the risk higher,while vulnerability makes the risk lower;Turpan is the city with the highest hazard contribution(81.69%)to risk,Shenzhen is the exposed-causing city with the largest exposure contribution(77.22%),and Pingliang is the vulnerable-causing city with the largest vulnerability contribution(83.02%).(2)In 2015-2074,the highest intensity of high temperature is distributed in Xinjiang Turpan City,South China,and East China,and the average of the highest intensity of high temperature in all emission scenarios is 272875℃,with an overall obvious warming trend,with an average annual increase of 11.232℃,and the largest growth rate in the ssp585 scenario.2035-2054 compared to 2015-2034 The areas with the largest warming are mainly around the northeast and north China,with the largest national increase of 7829.12°C.The main warming area in 2055-2074 compared to 2035-2054 is the Tibetan region,with an increase in high temperature intensity of 8285.95-11203.16°C.In the monthly traces,the high temperature intensity is at the maximum in July,and the high temperature intensity is small from October to April.(3)From 2015 to 2074,the highest frequency of high temperature is distributed in Tulufan city,Xinjiang,southwest and east China,with the average maximum high temperature frequency under all scenarios of 119.046 days highest frequency under ssp585 in the same period.The overall average annual high temperature frequency in China shows a clear trend of increasing by 160.30 times per year on average,with the largest growth rate under ssp585.2035-2054 shows the largest increase in high temperature frequency over2015-2034 in southern Hebei,western Shandong,northeastern Henan,western Xinjiang Bayin State,eastern Hotan,and southeastern Aksu,reaching 6.27-10.78 days.2055-2074 compared to 2035-2054,the largest increase in Sichuan Bazhong,southern Guangyuan,eastern Dazhou,Guang’an,Nanchong,Suining,Xinjiang Turpan,Hami,Bayin State,southern Aksu,northern Hotan,and eastern Kashgar,reaching 6.06-11.34 days.High tempera greatest in July,followed by August and June,and less frequently from September to May.