Saline intrusion in the Ganges-Brahmaputra-Meghna megadelta
Saline intrusion in the Ganges-Brahmaputra-Meghna megadelta
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DOI：
10.1016/j.ecss.2021.107246
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发表时间：
2021-05
期刊：
影响因子：
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通讯作者：
L. Bricheno;J. Wolf;Yujuan Sun
中科院分区：
文献类型：
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作者：
L. Bricheno;J. Wolf;Yujuan Sun
在肥沃的恒河-雅鲁藏布江-梅克纳三角洲，跨越印度和孟加拉国的西孟加拉边界，淡水的供应对维持生计和保护生态系统至关重要。受大潮汐和变化很大的河流流量的控制，三角洲经历了河流盐度和盐的入侵，以及季风期间的季节性洪水。未来的气候变化预计将增加南亚的降雨量和GBM系统的河流流量。我们解决这个过程可能会联合收割机与海平面上升（SLR），以控制未来的河流盐度。利用一系列SLR和气候变化情景设计的模型实验，研究控制三角洲河流盐度的力量。一个灵活的网格建模方法使我们能够在广泛的时间和空间scales.In未来的预测之间的差距湿和旱季盐入侵加剧的影响。在未来，SLR将增加GBM三角洲的河流盐度。在旱季，这种影响因河流流量减少而恶化。在雨季，三角洲东部的季节性河流流量较大，可以缓解这种情况。中西部三角洲以盐下侵蚀为主，常年盐侵加剧，影响水资源和农业生产力。在水文循环加剧的背景下，这些结论具有类似的潮汐主导的三角洲，SLR可以增加潮差，从而加剧盐入侵的影响。
In the fertile Ganges-Brahmaputra-Meghna (GBM) delta, which spans the boundary from West Bengal in India and Bangladesh, the availability of freshwater is crucial to subsistence livelihoods and protected ecosystems. Controlled by large tides and widely variable river discharge, the delta experiences rising river salinity and salt intrusion, as well as seasonal flooding during the monsoon.Future climate change is projected to increase rainfall in South Asia and river discharge in the GBM system. We address how this process might combine with sea-level rise (SLR) to control future river salinity. Model experiments designed using a range of SLR and climate change scenarios are performed to investigate the forces controlling river salinity in the delta. A flexible mesh modelling approach allows us to investigate the impacts at a wide range of time and space scales.In future projections the disparity between wet and dry season salt intrusion intensifies. In the future, SLR acts to increase river salinity in the GBM delta. During the dry season, this effect is worsened by reduced river discharge. In the wet season, this can be mitigated in the eastern part of the delta by larger seasonal river flows. The central and western delta is dominated by SLR, leading to increased salt intrusion all year round, impacting on water resources and agricultural productivity. In the context of an intensifying hydrological cycle, these conclusions have implications for similar tide-dominated deltas, where SLR can increase tidal range, and therefore exacerbate salt intrusion.