小浪底—陶城铺河段河床沙波的模型分析

Analysis of Riverbed Sand Wave in the Physical Model of Xiaolangdi-Taochengpu Reach

对小浪底—陶城铺河段模型河床的沙波尺寸进行了量测统计,分析了模型试验条件下不同水沙条件、不同河段床面沙波的分布特征和沙波形态变化规律。结果表明:沙波尺寸自上游向下游逐渐减小,洪水对河床沙波形态的塑造比较均匀,连续性比较好,沙波尺度也较小;经过持续小水后,沙波形态变得比较离散,沙波的尺度也比较大;弯道河段的沙波尺度较过渡直河段偏大一些,河湾不同部位的沙波尺度变化不大;河道来水条件和河床比降、床沙中径等因素对河床沙波的形成及几何形态特征具有明显影响。

The size of riverbed sand wave of the physical model was measured to analyze sandwave distribution characteristics and sandwave evolvement in different sections of the lower Yellow River on different water and sediment conditions in the model experiment.The results show that：the size of the sand wave is decrescent from the upriver to downriver,the sandwave form is smaller,more even and successional on the condition of small current than in the flood;the sand wave size is bigger in the curve channel than in the straight;the size is changeless in the different part of the same river bend;the form and the shape characteristic of sand wave are affected observably by the water condition gradient and grain size and so on.