ABSTRACT
64In order to cover the crop water requirements, the canals are operated to transfer the desired amount of water to the field canals by using the flow control structures like gates and weirs. In this chapter the impact of gate operation and selection of gates on the deposition of non-cohesive sediment is examined. The Delft3D model is used to simulate the effects of different scenarios regarding gate operation and the location of the gate that is opened. The model results showed that the gate selection affects not only hydraulic parameters but also morphological parameters. It was found that opening the gates closer to the offtake resulted in less sediment deposition at the entrance of the branch canal as compared to opening the gates further away. Gate selection can be used as tool in sediment management. By alternating the opening of different gates sediments which are already deposited by opening one gate can be eroded when another gate is operated, thus minimizing the additional cost of sediment removal. The use of Delft3D proved beneficial as the selection of different gates leads to asymmetric sediment deposition patterns which would be missed when using a 1D model.
