Studying the effect of sediment control structures of sill on sediment entrance into the intake with different angles

Using lateral intake is a method of floodwater diverting. In arid and semi-arid areas, floodwatercontains a large amount of sediment that will be carried in to the intakes and it causes a reduction inchannel conveyance. Sediment is almost transported into the intake and it is settled in the upstreamside of lateral channel. Sedimentation in this zone reduces the conveyance of lateral channel and itblocks the entrance of intake. There are several methods to reduce sediment transport into the intakethat one of them is noticed to the angle of lateral channel related to the flow direction in the mainchannel. Using the sediment control structures such as sill is the other approach. In the present study,CCHE2D model is used to simulate the results of a laboratory study that has been conducted in thepast. The laboratory study has been experimented in a flume approximately 17 m in length, 1.5 m inwidth and 7 m in depth. The intake connected to the flume has a width of 0.6 m, a length of 2.5 m withdifferent angles of 90, 75, 60 and 45 degrees to the flow main direction. The bed material was sandwith an average diameter of 1 mm that is casted in 20 cm thick on the bed of flume. The modelCCHE2D was applied once as a simple model and again a model with use of a sill with height of 3.5cm and 1 cm thickness at the entrance of intake, Range of tests was so that there was just movement ofbed load. Presence of sill structure has been approximately decreased 26 percent of the sedimententrance into the intake, whereas this figure for the tests was 30 percent. This indicates the ability ofCCHE2D model to predict the sill effect on sediment control.