Interrelationship Between Erosion and Deposition in Curved Channel

Concave side meandering damages cities, agricultural land and hydraulic and other structures. These damages are the function of convex side sedimentation of river. The maximum height of sedimentation occurs in the zone of separation which creates the adverse longitudinal gradient in the sand bed as compared to that of the stream. The static sand bed on convex side continuously changes its friction; form and pressure drag forces responsible for increasing concave side depth of water and position of point of maximum depth at concave side. This is intensified with the increase in distance downstream. The inter-relationship between sedimentation and erosion in the case of the Ganga at Varanasi and in the laboratory flume having two 1800 consecutive bends of the reverse order is presented. It has been found that as the depth of sedimentation increases with the increase in distance downstream the depth of maximum erosion on the concave bank side increases and its location shifts closer to the bank. Thus, the maximum depth of erosion at concave side and its location from the concave bank corresponds to the maximum height of sand bed at convex side.