挟沙能力多值性及黄河下游多来多排特性分析——“黄河调水调沙的根据、效益与巨大潜力”之五

Analysis on Multi-Value of Sediment-Carrying Capacity and Characteristic of Desilting as Much as Coming in the Lower Yellow River

用大量实测资料表达了黄河下游多来多排的输沙特性，给出了数量范围，进而证实了多来多排是挟沙能力多值性的表现，并分析了多值性的定量结果。在采用抉沙能力多值性调整挟沙能力系数后，各种资料不同冲淤条件下挟沙能力的计算结果与实测值更为符合，相对误差为5％～9％。分析了多来多排的机理后认为：临界流速的非单值性是挟沙能力多值性的深层原因；从宏观上看，冲淤弱平衡是造成挟沙能力多值性的主要原因。最后论证了多来多排输沙特性是如何在调水调沙中应用的。

The paper shows the characteristic of desilting as much as coming in the lower Yellow River,gives the quantity and scope,proves desilting as much as coming is the characteristic of sediment carrying capacity and analyzes the quantitative result of multi-value by using a vast amount of observed data.After regulating the coefficient of sediment carrying capacity based the multi-value,the calculating results of the carrying capacity under the different scour and fill conditions more tally with the observed value and the relative error is 5%-9%.It deems after analyzing the mechanism of desilting as much as coming that non-uniqueness of critical velocity is the deep reason of multi-value of sediment carrying capacity and;viewing from macro point,the weak equilibrium of scour and fill is the main reason of causing multi-value of sediment carrying capacity.It finally proves how the application of the characteristic to the regulated discharge regime of the river.