Abstract
Sedimentation process in the Joumine Reservoir located in the semi-arid area of North Tunisia was studied by numerical simulation. The major sediment component flowing into the reservoir is fine silt of about 5 μm in diameter, and the high SS water carried by floods generates high-turbid current along the reservoir bed. A vertical 2-D flow model was developed to simulate the high-turbid flow, and the model performance was verified by comparison with the data obtained from field measurements. The model reproduced the longitudinal profile of bed deformation for 23 years after the dam construction fairly well. The computation showed the unsteady sedimentation process, in which the small and middle scale floods result in sediment deposition in the upstream reach while the self-accelerating gravity current caused by the large scale floods picks up and transports the sediment downstream to the deepest area near the dam body.
