Modeling impacts of climate change on freshwater availability in Africa
Modeling impacts of climate change on freshwater availability in Africa
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DOI：
10.1016/j.jhydrol.2012.12.016
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发表时间：
2013-02-14
影响因子：
6.4
通讯作者：
Yang, Hong
中科院分区：
文献类型：
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作者：
Faramarzi, Monireh;Abbaspour, Karim C.;Yang, Hong
本研究分析了2020-2040年气候变化对非洲次流域淡水供应的影响。在IPCC的四种排放情景下，五个全球环流模型（GCMs）的未来气候预测被输入到现有的SWAT水文模型中，以预测对整个非洲大陆水资源不同组成部分的影响。根据气候研究中心的观测资料，将gcm按0.5度网格空间分辨率进行了缩尺处理，以表示局地气候条件。结果表明，非洲作为一个整体，水资源的平均总量有可能增加。对于个别子流域和国家，差异很大。尽管模拟结果的不确定性较高，但我们发现，在许多地区/国家，大多数气候情景预测的水资源变化方向相同，这表明预测结果的置信度相对较高。对干旱天数及其发生频率的评估表明，未来干旱事件及其持续时间将会增加。总体而言，干旱地区对水资源影响的不确定性高于湿润地区。这给干旱地区的农业带来了额外的挑战，这些地区缺水已经很严重，而灌溉对于稳定和增加粮食生产将变得更加重要。(C) 2012 Elsevier B.V.版权所有
This study analyzes the impact of climate change on freshwater availability in Africa at the subbasin level for the period of 2020-2040. Future climate projections from five global circulation models (GCMs) under the four IPCC emission scenarios were fed into an existing SWAT hydrological model to project the impact on different components of water resources across the African continent. The GCMs have been down-scaled based on observed data of Climate Research Unit to represent local climate conditions at 0.5 degrees grid spatial resolution. The results show that for Africa as a whole, the mean total quantity of water resources is likely to increase. For individual subbasins and countries, variations are substantial. Although uncertainties are high in the simulated results, we found that in many regions/countries, most of the climate scenarios projected the same direction of changes in water resources, suggesting a relatively high confidence in the projections. The assessment of the number of dry days and the frequency of their occurrences suggests an increase in the drought events and their duration in the future. Overall, the dry regions have higher uncertainties than the wet regions in the projected impacts on water resources. This poses additional challenge to the agriculture in dry regions where water shortage is already severe while irrigation is expected to become more important to stabilize and increase food production. (C) 2012 Elsevier B.V. All rights reserved.