中文摘要：

研究黄河下游河道的中、较粗泥沙冲淤效率与细泥沙含量和全沙含沙量的定量关系,据此得到不同细泥沙含量条件下,中、较粗泥沙在黄河下游河道不发生淤积的临界含沙量。同时,结合黄河干流水库的分组排沙比与全沙排沙比的关系,给出小浪底水库不同入库含沙量条件下,中、较粗泥沙在下游河道不发生淤积的水库排沙比。

英文摘要：

Owing to the main deposition of medium and coarse sediment in the lower waterway of Yellow River,a quantitative relationship among the erosion and deposit efficiency of medium and coarse sediment,the concentration of fine sediment and the concentration of entire sediment was obtained.On such a basis,the critical sediment concentration to avoid deposition of the medium and coarse sediment in the lower waterway of Yellow River under different fine sediment concentrations was yielded.Simultaneously,based on the relationship between grouping sediment releasing ratio and entire sediment releasing ratio,the sediment releasing ratio of Xiaolangdi Reservoir to avoid deposition of the medium and coarse sediment in the lower waterway of Yellow River under different inflow sediment concentrations was put forward.