The impacts of climate change on river flood risk at the global scale
The impacts of climate change on river flood risk at the global scale
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DOI：
10.1007/s10584-014-1084-5
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发表时间：
2016-02-01
期刊：
影响因子：
4.8
通讯作者：
Gosling, Simon N.
中科院分区：
文献类型：
--
作者：
Arnell, Nigel W.;Gosling, Simon N.
本文对气候变化对全球河流洪水风险的影响进行了评估。它的基础是以0.5x0.5度的网格分辨率估计洪水频率关系，使用一个全球水文模型，其中包括从21个气候模型得出的气候情景，以及对未来人口的预测。计算了洪水风险的四个指标：洪峰的大小和重现期的变化、洪水易发人口和农田在洪水频率发生重大变化时的变化，以及基于频率曲线和一般洪水损害函数相结合的区域洪水风险的通用度量。根据一个气候模型、排放量和社会经济情景(HadCM3和SRES A1b)，到2050年，当前的百年一遇的洪水发生频率将至少是全球40%的两倍，大约4.5亿易发洪水的人和43万公里(2)易发洪水的农田将面临加倍的洪水频率，在没有气候变化的情况下，全球洪水风险将比2050年的风险增加约187%。存在很强的区域变异性(最不利的影响将发生在亚洲)，不同气候模型之间存在相当大的变异性。2050年，在SRES A1b下的21个气候模型中，增加暴露的范围是3100万至4.5亿人和59000至43万公里(2)的农田，风险变化在-9%至+376%之间。文中介绍了全球平均地表温度变化对全球洪灾的影响，以及全球平均地表温度变化与全球洪灾影响之间的关系。这项分析有一些需要注意的地方：它只基于一个全球水文模型，气候情景是使用模式尺度构建的，精确的影响对定义和应用中的一些假设很敏感。
This paper presents an assessment of the implications of climate change for global river flood risk. It is based on the estimation of flood frequency relationships at a grid resolution of 0.5x0.5 degrees, using a global hydrological model with climate scenarios derived from 21 climate models, together with projections of future population. Four indicators of the flood hazard are calculated; change in the magnitude and return period of flood peaks, flood-prone population and cropland exposed to substantial change in flood frequency, and a generalised measure of regional flood risk based on combining frequency curves with generic flood damage functions. Under one climate model, emissions and socioeconomic scenario (HadCM3 and SRES A1b), in 2050 the current 100-year flood would occur at least twice as frequently across 40% of the globe, approximately 450 million flood-prone people and 430 thousand km(2) of flood-prone cropland would be exposed to a doubling of flood frequency, and global flood risk would increase by approximately 187% over the risk in 2050 in the absence of climate change. There is strong regional variability (most adverse impacts would be in Asia), and considerable variability between climate models. In 2050, the range in increased exposure across 21 climate models under SRES A1b is 31-450 million people and 59 to 430 thousand km(2) of cropland, and the change in risk varies between -9 and +376%. The paper presents impacts by region, and also presents relationships between change in global mean surface temperature and impacts on the global flood hazard. There are a number of caveats with the analysis; it is based on one global hydrological model only, the climate scenarios are constructed using pattern-scaling, and the precise impacts are sensitive to some of the assumptions in the definition and application.