Mathematical Modelling of Long-term Sedimentation of Reservoirs

This paper describes the use of a two dimensional (2DH) hydrodynamic model to simulate sedimentation at three case study reservoirs: Elandsdrift and Darlington Dams in South Africa and the proposed polihali Dam in Lesotho. These reservoirs were selected since they are narrow and shallow, wide and shallow, and narrow and deep, respectively, to demonstrate the application of the model for different shapes and sizes of reservoirs. The model simulates the cohesive sediment coupled with the hydrodynamics. The model was calibrated successfully against field sediment deposition data on two reservoirs. Long-term simulations were also carried out up to 100 years at Polihali dam.