小浪底水库拦沙初期泥沙输移及河床变形研究

应用物理模型试验对小浪底水库运行初期的泥沙输移和河床变形进行了一系列的研究预测,结果表明水库运用初期基本上为异重流排沙;库区干流淤积形态为三角洲且不断向下游推进;支流淤积主要是干流倒灌的结果,在沟口可形成拦门沙;库水位大幅下降,干流河床将产生溯源冲刷和沿程冲刷,支流淤积面随之下降。水库投入运用以来的实测资料分析表明,尽管预报试验所采用的水沙条件与水库运用以来的实际情况不尽相同,但两者在输沙流态、淤积形态及变化趋势方面基本一致,从而证明了模型试验得出的结论是符合实际的。

Sediment transport and morphological changes of the Xiaolangdi Reservoir in early sediment impoundment period

Physical model tests were conducted to forecast the regime of the sediment transport and morphological changes of the Xiaolangdi Reservoir in the early sediment impoundment period.The experimental results show that the sediment transport in the early operation period took the mode of density current;in the main river channel sediment appeared in the form of delta deposition,which moved towards the dam;the deposition also occurred in the branches and gullies,especially when sand bar existed at the junctions due to the sediment-laden flow inversely running from the main river channel to the branches and gullies.When the reservoir water level sharply fell,headward erosion and bank erosion occurred in the main riverbed and the siltation area will be reduced in the branches and gullies. Although the model conditions in the experiments didn't fully agree with those of the prototype in the real case,the general agreement of the data measured in situ with those predicted in model has validated the rationality of experiment.