一、前言河岸侵蚀通常发生在河道弯曲处,在这些地方,由于流速的垂直梯度和水流曲度相互影响而产生一种通常所说的二次流或涡流。二次流的表面流速度快,向外运动,而底部流速度慢,向内运动,因而致使外岸近处河道变深,流速加大。河道变深会削弱河岸坡脚的支撑能力,加上冲击流速较大,结果河岸进入冲蚀阶段。 I. INTRODUCTION Riverine erosion usually occurs at the bend of a river where a so-called secondary flow or vortex is created due to the interaction of the vertical gradient in flow velocity and the flow curvature. The surface flow rate of the secondary flow is fast and outward, while the velocity of the bottom flow is slow and moves inwards. As a result, the depth of the outer waterway becomes deeper and the flow rate increases. The deepening of the river will weaken the supporting capacity of the foot of the river bank, and the larger the impact velocity, the river bank will enter the erosion stage.