变化环境下中国东南沿海致灾气旋及其人口暴露度研究

Hazard-inducing tropical cyclones and exposed population in southeast China coast

本文基于气象观测站的逐日气压、风速和降水量确定致灾气旋阈值,结合区域气候模式COSMO-CLM(CCLM)输出,研究中国东南沿海地区2021—2050年RCP2.6、4.5、8.5情景下致灾气旋的时空变化特征。并采用人口-发展-环境分析模型(PDE),预测共享社会经济路径SSP2下东南沿海地区人口发展趋势,揭示了致灾气旋人口暴露度演变。研究表明:(1)RCP2.6情景,东南沿海地区平均每年发生致灾气旋6.3次,风速和降水量较基准期(1986—2005年)分别增加9%和15%,72%区域致灾气旋人口暴露度有所增加。暴露在超基准期最大影响面积和最强风速下的致灾气旋人口分别增加2.1亿和0.1亿。(2)RCP4.5情景,致灾气旋年均发生7次,风速和降水量较基准期分别上升16%和32%,89%地区致灾气旋暴露人口增加。暴露在超基准期最大影响面积和最强风速下的致灾气旋人口分别增加2.6亿和0.5亿。(3)RCP8.5情景,致灾气旋年均发生5.8次,风速和降水量较基准期分别增加32%和50%,65%区域致灾气旋暴露人口度有所增加。暴露在超基准期最大影响面积和最强风速下的致灾气旋人口分别增加5.7亿和1.9亿。(4)相比RCP2.6,RCP8.5情景致灾气旋风速和降水量高出23%和35%,暴露于超基准期最大影响面积和最强风速的致灾气旋人口分别多3.6亿和1.8亿。控制温室气体浓度对降低致灾气旋的不利影响具有重要意义。

The threshold of hazard-inducing tropical cyclone in southeastern China coast is determined based on daily air pressure,wind speed and precipitation data from observational meteorological stations.Output of regional climate model COSMO-CLM(CCLM)is used to analyze the characteristics and spatial-temporal distribution of hazard-inducing tropical cyclones in 2021-2050 under RCP2.6,4.5,8.5 scenarios,respectively.We also project the population change in the southeast coast under the shared socioeconomic pathways(SSP2)by using the Population-Development-Environment Model(PDE),and then reveal the evolution of population exposure to hazard-inducing tropical cyclones.Results show that:(1)under RCP2.6 scenario,hazard-inducing tropical cyclones will occur 6.3 times per year,with increase of average wind speed and precipitation by 9%and 15%,and increase of population exposure at 72%of southeast China than 1986-2005.Population exposed to stronger than historical hazard-inducing tropical cyclones in 1986-2005,which has the maximum affected area and highest wind speed,will increase by 210 million and 10 million,respectively.(2)Hazard-inducing tropical cyclones are projected to occur 7 times per year under RCP4.5 scenario,with increase of wind speed and precipitation by 16%and 32%than 1986-2005.Meanwhile,population exposure of the 89%region will increase.Population exposed to stronger than historical events with maximum coverage and highest wind speed will increase by 260 million and 50 million,respectively.(3)Under RCP8.5 scenario,frequency of hazard-inducing tropical cyclones will be 5.8 times per year,and their wind speed and precipitation will increase by 32%and 50%with relative to reference period,and population exposure increase in 65%of the region.Population exposed to stronger than historical events with maximum coverage and highest wind speed will increase by 570 million and 190 million,respectively.(4)Wind speed and precipitation will increase by 23%and 35%under RCP8.5 scenario with relative to RCP2.6.Population exposed to stronger than historical events with maximum coverage and highest wind speed will increase by 360 million and 180 million respectively.Controlling of greenhouse gases is meaningful to reduce the adverse effects of hazard-inducing tropical cyclones.