“一带一路”区域极端高温事件与人口暴露度特征

Spatial-temporal patterns of population exposed to the extreme maximum temperature events in the Belt and Road regions

基于1979-2018年"一带一路"区域再分析数据集(ERA-Interim)夏季逐日最高气温和格网化的人口数据,选取日最高气温序列的95%分位数作为极端高温阈值,采用改进的强度-面积-持续时间(IAD)方法,辨识极端高温事件特征,并定量评估极端高温事件的人口暴露度。结果表明,1979-2018年"一带一路"区域夏季极端高温事件频次、强度和持续时间均呈上升趋势,年均值分别为11次、32.3℃和5.8 d,显著增加区域分布在中国东部、俄罗斯西部、中东欧地区;夏季极端高温事件多发于研究区偏北地区的哈萨克斯坦、中国新疆、俄罗斯中部等,但事件的强度高值区主要分布在西南部的埃及、沙特阿拉伯、巴基斯坦、印度等地,事件持续时间高值区集中分布在印度地区;1979-2018年夏季极端高温事件的年累计影响面积和人口暴露度均呈现上升趋势,近10年达到峰值。人口暴露度高值区主要分布在中国东部、印度大陆和黑海周边国家,且高暴露度范围不断扩大;人口暴露度变化的影响因素中,气候、人口、气候和人口综合因素的贡献率相当,但近10年气候因素的贡献率明显增加。建议加强高温等极端事件的监测、预警预报与区域合作研究,建立区域合作共同体,并培养和加强公众科学防灾减灾意识。

This paper investigates the extreme maximum temperature event characterization and the population exposure in the Belt and Road regions by using the maximum temperature form ERA-Interim reanalysis dataset and the gridded population dataset in the period from 1979 to 2018.The extreme maximum temperature threshold is determined based on the 95%quartile of the daily maximum temperature.The improved Intensity-Area-Duration(IAD)method is used to determine the extreme maximum temperature event characteristics and the quantitative assessment of the population exposure to these extreme events.It is shown that,in the Belt and Road area,the frequency,the intensity and the duration of the summer extreme maximum temperature events are increased in the 1979-2018 period.The significant increase area is distributed in eastern China,western Russia and Central Eastern Europe.In summer,the extreme maximum temperature events mostly occur in Kazakhstan,Xinjiang,and central Russia,generally,in the northern part of the study area.The intensity high value area is mainly distributed in Egypt,Saudi Arabia,Pakistan,India and other places in the southwest region whereas the duration high value area is concentrated in India mainly.During the study period,the yearly cumulative impact area and the population exposure to extreme temperature events show an upward trend,reaching the highest value in the past 10 years.Areas with the high population exposure are mainly distributed in eastern China,Indian continent and countries around the Black Sea and the areas with high population exposure are expanding.Among the influencing factors of the population exposure,the climate factor,the population factor,the interaction of the climate and population factors have a similar contribution rate,but the contribution rate of the climatic factors has increased significantly in the past 10 years.It is suggested to strengthen the research of monitoring,warning and forecast of the extreme maximum temperature events.