Experiments on channel evolution caused by check-dam failure

Abstract

A 10 m long, 0.2 m wide flume was employed to simulate the channel bed evolution of check-dam failure. The experiment longitudinal profiles, the gradient of channel bed, head-cutting propagation distance and deposition length were compared with the theoretical solution derived from a sediment transport diffusion equation. In contrast with the theoretical solution, two different gradients were obtained upstream and downstream of the check-dam. The theoretical solution provides a good description of the changes upstream of the check-dam. The ratio of clear water depth to sediment moving layer thickness in the experiment was analyzed and showed that high concentration sediment laden flow was taken in the incipient of check-dam failure, which may be the reason why the experiment result was slightly different from the theoretical solution in the downstream of check-dam.