Experimental Study of Sediment Control at Wide Reaches

Abstract

It has been supposed that the oval shape reaches whose width changes from wide to narrow or from narrow to wide in mountain rivers control the sediment produced by landslides and debris flows. The sediment control function was investigated through the experiments with straight flumes and curved flumes. The experiments gave some interesting discoveries. Firstly, channel gradient has the greatest influence on sediment control. The occurrence of hydraulic jump also chages the sediment control at the wide reaches. When hydraulic jump is formed narrower outlet gives more sediment control. When excessive sediment is supplied to un equilibrium condition, sediment discharge does not increase quickly, and control sediment. Secondary flow is generated from the side walls to the center of the flume on the flume bed near the outlet, which score the bed along the walls and control sediment discharge. The sediment control effect at wide reaches in explained with a one-dimentional computer simulation to some extent.