从水沙条件探讨黄河下游上下河段冲淤调整关系

Investigation on the sedimentation relation between the upper and lower reaches from the flow-sediment combination in the lower Yellow River

在以往对黄河下游河道上段 (高村以上 )和下段 (高村到利津 )冲淤调整关系研究的基础上 ,通过 196 0～1999年 4 2 2场次洪水资料的统计分析 ,按三门峡水库不同运用期分析了上下段的冲淤关系 ,建立了上下段排沙比与水沙系数的关系 ,认为上下段冲淤关系随水沙搭配条件而变 :水流严重不饱和时上下段冲淤性质一致 ;轻度不饱和情况下上下段冲淤性质相反 ;水沙搭配基本平衡时上下段冲淤变化不大。根据上下段冲淤临界水沙系数关系绘制了上下段冲淤关系图 ,并首次按三黑小 (三门峡、黑石关、小董三站 )水沙搭配进行了定量分区 :上冲下淤、上淤下冲。

The paper summarized previous researches on the relation of channel formation between the upper and the lower reaches in the lower Yellow River from flow/sediment conditions, analyzed statistically the hydrological data of 422 floods from 1960 to 1999 and set up sediment transport equations for the upper and the lower river reaches. Then the critical conditions between scour and siltation for the upper and the lower river reaches are derived as a function of flow discharge and sediment concentration as shown in Fig.7, which indicates that the river channel would be scoured when flow is relatively clear, and filled when flow is relatively muddy. The upper and the lower reaches of the lower Yellow River would be scoured/silted simultaneously when the flow is badly unsaturated with sediment, the upper reach would be scoured and the lower reach would be silted when the inflow is relatively clear, the upper reach would be silted and the lower reach would be scoured when the inflow is relatively muddy.