中文摘要：

在系统分析黄河小浪底水库2002年9月异重流小流量排沙期水沙演进、河床冲淤与沿程引水引沙情况的基础上，采用非恒定流准二维水沙数学模型，计算分析了下游沿程引水对河道演变的影响．计算结果表明，虽然异重流排出的悬沙组成很细，但由于流量不大，水流仍处于超饱和输沙状态；洪水期两岸的引水量占与水库下泄水量的比例很大，大量泥沙被引到堤外，与不引水相比较，河道淤积减少．

英文摘要：

Based on the systematical analysis of water and sediment routing during small stratified flow sediment transportation, riverbed scour and silting evolution and situation of water and sediment diversion along the river in Xiaolangdi Reservoir on the Yellow River in September of 2002, the unsteady flow quasi-2D numerical model is adopted to calculate and analyze the influence of lower Yellow River water diversion along the channel on river evolution. The calculating result shows that suspended sediment transported by the stratified flow is with small radius, however, according to the small flux, the flow is still in state of over-saturation sediment transport; the proportion of water diversion in lower river accounts for a large part of reservoir sluice capacity, and large quantity of sediment is induced outside of bank, which decreases the silt compared with non-water diversion.