Experimental Investigation of Sediment Entry to an Intake Installed at a Main Channel with Inclined Bank

A major problem with which most of the lateral intakes are faced is sedimentation and sediment delivery. This process causes many problems in irrigation systems such as reduction flow discharge capacity in irrigation canals and even threat of blockage of water during low water flow. Therefore an intake with higher flow discharge and low sediment delivery should be considered in the design. In previous research the same attention has not been given to the lateral intakes installed at trapezoidal canals, as for rectangular canals. The main goal of this study was to investigate sediment delivery to an intake from trapezoidal canal. Sediment tests were carried out for different hydraulic conditions at a 30 degree water intake installed at a main canal with inclined bank. It was found that the flow patterns at the upstream of the intake has been modified in such a way that more water from surface layers are diverted. Therefore less suspended sediment enters the intake. Also it was found that in all tests the amount of sediment enters the intake reaches its minimum value at Froude number between 0.35 to 0.4. For high friction coefficients, the rate of sediment entering the intake decreases as the flow ratio increases.