Impacts of Three Gorges Reservoir on the sedimentation regimes in the downstream-linked two largest Chinese freshwater lakes.
Impacts of Three Gorges Reservoir on the sedimentation regimes in the downstream-linked two largest Chinese freshwater lakes.
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DOI：
10.1038/srep35396
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发表时间：
2016-10-17
影响因子：
4.6
通讯作者：
Li X
中科院分区：
文献类型：
--
作者：
Zhou Y;Jeppesen E;Li J;Zhang Y;Zhang X;Li X
我们研究了三峡水库 (TGR) 对下游连接的两个最大的中国淡水湖洞庭湖和鄱阳湖沉积状况的影响。结果表明，2003年6月至2014年12月期间，三峡库中滞留泥沙量达1.73 × 109 t，导致枝城的悬浮泥沙量减少145.9 × 106 t yr−1，使从长江到洞庭湖的泥沙流量减少16.8 × 106 t yr−1，这部分解释了TGR后洞庭湖沉积量减少了13.4 × 106 t yr−1。此外，三峡工程还导致鄱阳湖出口湖口多年平均水位下降0.5±0.3米，加速了鄱阳湖悬浮泥沙的外排。据估计，三峡工程后鄱阳湖的沉积量减少了 6.3 × 106 t yr−1。我们估计，三峡库区的月平均泥沙浓度低于0.60 kg m−3，将导致洞庭湖和鄱阳湖的侵蚀。更好地监管 TGR 可能会延长这两个正在消失的大型湖泊的预期寿命。
We studied the impacts of Three Gorges Reservoir (TGR) on the sedimentation regimes in the downstream-linked two largest Chinese freshwater lakes, Lake Dongting and Lake Poyang. Our results indicate that up to 1.73 × 109 t sediment was retained in TGR from June 2003 to December 2014. This resulted in a 145.9 × 106 t yr−1 decline in the suspended sediment load at Zhicheng and a 16.8 × 106 t yr−1 lower sediment flow from Yangtze River to Lake Dongting, which partially explains the 13.4 × 106 t yr−1 lower sedimentation in Lake Dongting during the post-TGR period. Furthermore, TGR resulted in a 0.5 ± 0.3 m reduction of the multi-year mean water level at the Lake Poyang outlet Hukou, accelerating the suspended sediment export discharge from the lake. The reduced sedimentation in Lake Poyang during the post-TGR period was estimated to 6.3 × 106 t yr−1. We estimate that a monthly mean concentration of sediment flow from TGR below 0.60 kg m−3 will lead to erosion in Lake Dongting and Lake Poyang. Better regulation of TGR may extend the life expectancy of the two vanishing large lakes.