小浪底水库异重流对库区河床冲淤的影响

Effect of density currents in Xiaolangdi Reservoir on riverbed erosion and deposition

对小浪底水库异重流潜入位置、地形坡降、坝前水位及其库区河床地形的变化进行分析,结果表明:异重流的发生、运行及其消亡受制于地形的改变和进出库水沙量的影响;库区地形影响异重流的排沙效果,反过来异重流又塑造了库区地形.小浪底水库随着淤积三角洲顶点的不断向前推进,近坝段的比降变陡,有利于异重流排沙,可减少库区的泥沙淤积.

The density currents in Xiaolangdi Reservoir, the topographical gradient, the upstream water level as well as the change of riverbed topography in the reservoir area were analyzed. The results indicate that the occurrence, and disappearance of the density currents are dependant on the changes in topography and the amount of sediment and water The topography of the reservoir area has effect on the release of sediment by the density currents, and the density currents also have an effect on the topography. The advancing of the deposition delta vertex of the Xiaolangdi Reservoir and the steep slope near the dam aid the release of sediment by the density currents and the reduction of sediment deposition in the reservoir area.