三峡水库运行后，上游来沙中大部分粗沙淤积于库尾，不仅减少了水库的有效库容，对库尾回水段的通航也将产生影响。为减少三峡库尾泥沙淤积，提出了一种新的水库减淤方式，即固定河段挖粗沙方案。该方案通过持续疏浚将入库粗沙大部分截留挖除，控制粗沙向上游延伸，可有效实现水库减淤。根据三峡库尾河道地形和淤积特点，提出了7种挖沙减淤方案，并采用一维非恒定流水沙数学模型，计算分析了不同挖沙方案的减淤效果，并对比提出推荐挖沙方案。%After the operation of Three Gorges Reservoir, most of the coarse sediment from upstream deposits in the tail area of the reservoir, reducing effective reservoir capacity and influencing the navigation. In order to reduce the deposition in the tail area of the reservoir, a new reservoir deposition reducing scheme is put forward, that is to dredge out the coarse sediment at fixed river reaches. By the continuously dredging, most of the in-coming coarse sediment can be trapped and excavated out, so as to con-trol the siltation stretching to the upstream and effectively reduce the reservoir siltation. We propose seven schemes according to topographic characteristics at different sedimentation locations. By one-dimensional unsteady flow-sediment mathematical mod-el, the sediment reducing effect of each scheme is analyzed and the optimal scheme is recommended.
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