2005~2017年中国热浪事件及人口暴露水平趋势

Trend of heatwave events and population exposure levels in China from 2005 to 2017

目的探讨2005~2017年中国热浪事件时空趋势及人口暴露水平。方法基于中国2901个区县在2005~2017年期间的逐日日均温再分析数据集,采用相对温度阈值定义方法,统计分析中国热浪事件发生区县数、发生频次、热浪日总天数与单次事件平均持续天数的时空分布特征,并结合中国人口数据计算人口加权热浪日暴露水平。结果 2005~2017年热浪事件在中国的影响呈整体增加趋势,其中2010年、2013年、2016年与2017年热浪事件整体影响较大;热浪事件在长江流域沿线省份的人口暴露水平较其他地区更高,其中上海市的年均人口加权热浪日暴露水平最高,其次是浙江省。结论中国热浪事件在时间上呈现上升趋势,在空间上呈扩张趋势,并以长江流域为热浪事件的人口暴露集中区域。

Objective To explore the temporal and spatial trends of heatwave events and population exposure levels in China from 2005 to 2017. Methods The daily average temperature reanalysis data set of 2,901 districts and counties in China from 2005 to 2017 were assessed with relative threshold definition to analyze the number of districts and counties where heatwave events occurred,frequency of occurrence,total heatwave days,and spatial and temporal distribution characteristics of average duration of a single event. The population-weighted heatwave daily exposure was calculated based on national population data. Results From 2005 to 2017,the impact of heatwave events in China showed an increasing trend. The heatwave events in 2010,2013,2016 and 2017 had the largest overall impact. Population exposure to heatwave events was higher in provinces along the Yangtze River Basin than in other regions,with Shanghai having the highest average annual population-weighted heatwave daily exposure,followed by Zhejiang Province. Conclusion China’s heatwave events showan upward trend in time and an expanding trend in space,and the Yangtze River Basin is the population exposure area of heat wave events.