基于CMIP6不同重现期的全球未来暴雨社会经济风险变化评估

Future global socioeconomic risk changes to rainstorms based on the different return periods of CMIP6

合理地评估极端降水在未来的风险大小及其相对于历史的变化有利于科学制定风险防范措施。论文基于耦合模式比较计划第六阶段(CMIP6)的共享社会经济路径(SSP)2-4.5中的24个全球气候模式的未来日降水模拟数据、ERA5再分析降水数据以及人口和国内生产总值(GDP)预测数据,评估了全球未来暴雨在4个重现期(5年、10年、20年、50年一遇)的社会经济风险及其相对于历史时期的变化。结果表明:(1)未来情景中大洋洲的暴雨强度最大,欧洲最小。随着重现期的增加,有暴雨发生的区域不断扩大,暴雨的强度也在不断增大。(2)不同重现期中欧洲和大洋洲的暴雨风险最小,亚洲和非洲的暴雨风险最大。(3)未来暴雨风险增加最明显的区域集中分布在亚洲的南部和东部沿海地区、非洲的中北部和东南部,以及北美洲的东部、西部和南部的沿海等地区;风险变化减少最明显的区域主要分布在欧洲中部和南部、非洲西北部和东部、南美洲的北部等地区。随着重现期的增长,风险变化表现为增加的栅格占比增加。(4)在10个风险变化显著的国家中,4个重现期下与风险变化相关程度最大的要素各有不同。俄罗斯的风险变化与暴雨强度变化的相关程度最大,美国、巴西、印度、墨西哥、刚果民主共和国、阿根廷、澳大利亚7个国家的风险变化与人口变化的相关程度最大,加拿大和中国的风险变化与GDP变化的相关程度最大。研究可为受极端降水影响区域的防灾减灾提供一定的理论支撑。

A reasonable assessment of the risk of extreme precipitation in the future and its changes relative to the past is conducive to the scientific formulation of risk prevention measures.Based on the future daily precipitation simulation data of 24 global climate models of the Shared Socioeconomic Pathways(SSP)2-4.5 in the sixth phase of the Coupled Model Intercomparison Program(CMIP6),the reanalysis precipitation data of ERA5,and the prediction of population and gross domestic product(GDP),this study evaluated the socioeconomic risk of future global rainstorms at four return periods(5 years,10 years,20 years,50 years)and their changes relative to historical periods.The main conclusions are as follows:1)Under the future scenarios,the rainstorm intensity in Oceania is the highest and that in Europe is the lowest.With the increase of the return period,the areas where rainstorms occur continue to expand,and the intensity of rainstorms is also projected to increase.2)At different return periods,the rainstorm risk in Europe and Oceania are the lowest,and that in Asia and Africa are the highest.3)The regions with the most obvious increase of rainstorm risk in the future are concentrated in the southern and eastern coastal areas of Asia,the central,northern,and southeastern areas of Africa,and the eastern,western,and southern coastal areas of North America.The regions with the most obvious risk reduction are mainly distributed in central and southern Europe,northwestern and eastern Africa,and northern South America.With the increase of the return period,the proportion of the grids with increased risk is projected to increase.4)The factors that are most related to risk changes at the four return periods differ in the10 countries with significant changes in risk.The risk change of Russia has the greatest correlation with the change of rainstorm intensity.The risk changes of the United States,Brazil,India,Mexico,the Democratic Republic of the Congo,Argentina,and Australia have the greatest correlation with the change of population.The risk changes of Canada and China have the greatest correlation with the change of GDP.The study can provide a certain theoretical support for disaster prevention and mitigation in areas affected by extreme precipitation.