RCP4.5情景下中国人口对高温暴露度预估研究

Future population exposure to high temperature in China under RCP4.5 scenario

基于CMIP5的逐日最高温度模拟资料、GGI情景数据库逐年代人口数据,在RCP4.5情景下,以对应栅格高温日数与人口数量的乘积作为人口对高温的暴露度指标,通过多模式集合平均预估未来中国人口对不同强度高温的暴露度变化。结果表明:相比于基准时段(1981-2010年),中国人口对高温和强危害性高温的暴露度从2021-2040年开始明显增加,至2081-2100年暴露度分别增加了5.7倍和17.5倍;除了中国西部部分地区外,全国大部地区人群均受高温的影响,在21世纪中后期中东部大部人口对高温的暴露度超过10.0×106人?d;相比基准时段,随着年代的增长,中国人口对强危害性高温的暴露度在范围和强度上均有明显增加;2081-2100年,人口对高温和强危害性高温的暴露度增幅减缓。从气象地理区域上看,未来各时段人口对高温、强危害性高温的暴露度均有一定程度增加,但增加明显的区域主要集中在华北、黄淮、江南和江淮地区,华南地区对强危害性高温的暴露度增幅较小。高温日数变化对全国人口对高温暴露度的变化所产生的作用最明显。多模式集合的预估结果可以为防控未来高温风险提供重要的参考价值。

Based on daily maximum temperature data of CMIP5 models from NASA under RCP4.5 scenario and decadal population data of GGI database from IIASA under SRES B2 scenario, taking the multiplication of mean high temperature days and population of corresponding period as the index of population exposure to high temperature and heavy high temperature, 21 models were integrated to predict future population exposure to high temperature in China. Compared with baseline （1981-2010）, mean population exposure to high temperature and heavy high temperature will increase significantly and reach about 6.7 and 18.5 times separately in the period of 2081-2100. For regional scale, except for west China, most people in central-east China and north China are affected by high temperature. Population exposure to high temperature will exceed 40 ~ 106 person＇day during 2041-2060, 2061-2080, 2081-2100 in the central-east China. Before 2081, population exposure to high temperature will increase significantly in each period but drop in 2081-2100. Similarly, future population exposure to heavy high temperature will increase at the range and intensity with the period developing under RCP4.5 scenario, with population exposure to heavy high temperature only in central China expanding to the north and centraleast China. Beijing, Tianjin, north Hebei, northeast Henan, east Hubei and west Hunan are the major districts with a high increment of population exposure to heavy high temperature in periods. As for climatic region, increment of future population exposure to high and extremely high temperature will differ in periods and are mainly found in the Huang-Huai region, North China, and regions south of the Yangtze River. The small increment for population exposure to extremely high temperature exists in South China. Through analysis of factors affecting exposure, variation of high temperature is the main one, followed by interaction of high temperature and population, variation of population. Our results can provide a better understanding of people＇s exposure to high temperature and help for the policy formation of disaster management.