Study of the effect of various scenarios of the sediment ‎control on banks in the vicinity of lateral intake ‎entrance

One of the main goals in diverting water in rivers is to provide required water ‎with a minimum of sediments, which is usually met through installation of sediment control structures with different ‎arrangements to significantly decrease the sediment that enters the intake.In addition to sediment control,serious ‎attention should also be paid to impact of these structures and sediment control scenarios on the riverbank and ‎other relevant facilities located in vicinity of intake entrance. Using a laboratory scale canal,equipped with ‎recirculating sediment and included a 90◦lateral intake and a bed moving because of dunes movement, the effects of ‎these structures including sill,dike, and submerged vanes on the banks in the vicinity of intake entrance was ‎experimentally investigated at four different sediment control scenarios and different discharge ratio. In order to ‎accurately evaluate the scour near banks, after dynamic equilibrium was achieved at the bed due to continuous ‎changes of its elevation in these conditions,scour time series analysis was performed at upstream and downstream ‎points near the intake, along the banks on either sides of main canal.results show that different behaviors are ‎observed near intake due to various factors influencing the flow. While, in range of discharge ratios studied dike increases depth and length of scour zone at intake downstream by an average of about72%and‎‎34%, respectively, vanes reduces length of zone by37% and at discharge ratio of0.12, an ‎increase of about 66% in depth of scour zone is observed, while at discharge ratio of0.18, a decrease of‎‎24% in depth of zone occurs.‎