黄河水沙关系协调度与骨干水库的调节作用

提出了水沙关系协调度的概念,认为黄河协调的水沙关系是指长时段内维持下游河道(主槽)不淤或微淤的水沙搭配过程。黄河下游冲淤平衡临界来沙系数是0.01 kg·s/m6,采用来沙系数和冲淤平衡临界来沙系数相对关系建立了黄河水沙关系协调度表达式。当水沙关系协调度大于1,说明某断面来沙系数大于河道冲淤平衡临界来沙系数,河道呈现淤积状态,水沙关系不协调;反之,当水沙关系协调度小于1,说明水沙关系协调,且数值越小说明协调程度越高。小浪底水库拦沙和调水调沙提高了水沙关系协调程度,减轻了下游河道淤积,但是小浪底水库拦沙库容淤满后,黄河下游的水沙关系会变为不协调,河道仍将处于淤积状态。

Coordination degree of water-sediment relationship of the Yellow River and regulating effect of the backbone reservoir

The concept of coordination degree of water-sediment relationship is put forward in this paper, which indicates that the coordinated water-sediment relationship of the Yellow River refers to maintaining the balance of sediment transport in the Lower Yellow River for a long period. An expression of the coordination degree of the water-sediment relationship of the Yellow River was established by the ratio of the incoming sediment coefficient and critical incoming sediment coefficient, and the critical incoming sediment coefficient of the lower Yellow River is 0.01kg·s/m⁶. When the coordination degree is greater than 1, it means that the incoming sediment coefficient is greater than the critical incoming sediment coefficient, and the water-sediment relationship is uncoordinated and the channel will be in a silting state. Conversely, when the coordination degree is less than 1, the water-sediment relationship is coordinated. The smaller the value is,the more coordinated the water-sediment relationship is. The sediment trap and the water-sediment regulation of the Xiaolangdi Reservoir have played a significant role in coordinating the water-sediment relationship and reduced siltation in the Lower Yellow River. However,after the reservoir siltation capacity completely consumed,the water-sediment relationship in the Lower Yellow River will become uncoordinated and the main channel will recover silting.