Impacts of climate change and socio-economic scenarios on flow and water quality of the Ganges, Brahmaputra and Meghna (GBM) river systems: low flow and flood statistics.
Impacts of climate change and socio-economic scenarios on flow and water quality of the Ganges, Brahmaputra and Meghna (GBM) river systems: low flow and flood statistics.
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DOI：
10.1039/c4em00619d
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发表时间：
2015-06
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影响因子：
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通讯作者：
P. Whitehead;Emily Barbour;M. Futter;S. Sarkar;H. Rodda;J. Caesar;D. Butterfield;Li Jin;Rajiv Sinha;Robert J. Nicholls;M. Salehin
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文献类型：
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作者：
P. Whitehead;Emily Barbour;M. Futter;S. Sarkar;H. Rodda;J. Caesar;D. Butterfield;Li Jin;Rajiv Sinha;Robert J. Nicholls;M. Salehin
气候变化和社会经济变化对全球河流流量和水质的潜在影响是一个关键的关注领域。恒河-布拉马普特拉河-梅克纳河（GBM）是世界上最大的河流流域之一，为6.5亿多人口提供服务，是印度和孟加拉国的重要关切，因为它为人民，农业，工业，保护和下游三角洲系统提供淡水。本文旨在评估未来的流量和水质变化，利用建模方法作为一种手段，在一个非常复杂的系统的评估。INCA-N模型已被应用于恒河、雅鲁藏布江和梅克纳河水系，以模拟在一系列未来气候条件下沿着的流量和水质。从17个扰动模式运行中选择了气象局哈德利中心全球和区域气候模式的三个模式实现，以评估气候的一系列潜在未来。此外，还使用社会经济情景对这些模型进行了评估，这些情景包括：（1）一切照旧的未来;（2）更可持续的未来;（3）不太可持续的未来。2050年代和2090年代的模型结果表明，在未来的气候条件下，季风流量将显著增加，洪水潜力将增强。据预测，随着干旱期的延长，低流量将下降，这可能对水和沉积物供应、灌溉农业和盐水入侵产生影响。相比之下，社会经济变化对流量的影响相对较小，但在低流量制度下，增加灌溉可能进一步减少水的供应。然而，如果在孟加拉国上游建造大规模的调水工程，则有可能减少流量，并将水从三角洲地区转移出去，这取决于调水的数量和时间。这可能对三角洲的盐水入侵、供水、农业和维持红树林等重要生态系统产生重大影响，并对该地区人民的生计产生严重影响。社会经济情景对水质产生重大影响，改变了输送到三角洲地区的营养通量。
The potential impacts of climate change and socio-economic change on flow and water quality in rivers worldwide is a key area of interest. The Ganges-Brahmaputra-Meghna (GBM) is one of the largest river basins in the world serving a population of over 650 million, and is of vital concern to India and Bangladesh as it provides fresh water for people, agriculture, industry, conservation and for the delta system downstream. This paper seeks to assess future changes in flow and water quality utilising a modelling approach as a means of assessment in a very complex system. The INCA-N model has been applied to the Ganges, Brahmaputra and Meghna river systems to simulate flow and water quality along the rivers under a range of future climate conditions. Three model realisations of the Met Office Hadley Centre global and regional climate models were selected from 17 perturbed model runs to evaluate a range of potential futures in climate. In addition, the models have also been evaluated using socio-economic scenarios, comprising (1) a business as usual future, (2) a more sustainable future, and (3) a less sustainable future. Model results for the 2050s and the 2090s indicate a significant increase in monsoon flows under the future climates, with enhanced flood potential. Low flows are predicted to fall with extended drought periods, which could have impacts on water and sediment supply, irrigated agriculture and saline intrusion. In contrast, the socio-economic changes had relatively little impact on flows, except under the low flow regimes where increased irrigation could further reduce water availability. However, should large scale water transfers upstream of Bangladesh be constructed, these have the potential to reduce flows and divert water away from the delta region depending on the volume and timing of the transfers. This could have significant implications for the delta in terms of saline intrusion, water supply, agriculture and maintaining crucial ecosystems such as the mangrove forests, with serious implications for people's livelihoods in the area. The socio-economic scenarios have a significant impact on water quality, altering nutrient fluxes being transported into the delta region.