Mathematical Modeling of Sediment Deposition in Reservoirs

When a dam is constructed across a river basin to form a reservoir the velocity of the flow in the reservoir is reduced and the sediment transported by the river is deposited. These deposits accumulate to form deltas. Estimation of the amount and location of the sediment deposits is required for engineers in the design of dams. A mathematical model is developed for prediction of the delta formation in the reservoir by considering the river-reservoir system as a whole. The river is modeled by a single channel assuming one-dimensional flow phenomena are predominant, whereas a compound stream model approach is used to simulate the main river and the flood plains in the reservoir. The jet theory is incorporated in the mathematical model and the resulting flow field is used to route the sediment through the reservoir. The simulated bed profiles generated by the mathematical model compare well with measured data.