通过物理模型试验，利用NDV对泄水闸下泄水流右侧区域的三维流速进行测量，重点分析尾坎下游主泄流区和回流区的的水流特性，研究水流对河床的影响，分析南津渡水库闸坝下游河床冲刷破坏的原因。试验研究表明，造成南津渡水库下游回流区河床冲刷的主要原因是流速的分布特点，而造成主泄流区河床冲刷的主要原因是下泄水流所携带的紊动能。

Through physical model experiment and considering the characteristic of the main discharge area and return flow zone, the authors mainly analysed the influence of flow characteristic on the river bed and the reason of scouring on downstream river bed of Nanjindu Reservoir. In this experiment, the NDV was used to measure three dimensional flow velocities in the right region. The results show that the characteristics of flow velocity distribution is the main reason that causes scouring in the return flow area of river bed while turbulent energy is the main reason that causes scouring in main discharge area of river-bed.