Numerical Modelling of Delta Migration and Density Current Motion in a Reservoir

A fully three-dimensional numerical model was used to simulate different reservoir sedimentation processes simultaneously. Delta migration, density current movement, bore formation, underwater jump, and the associated velocity field in the reservoir were investigated. The model was validated by comparing measured and simulated concentration profiles and bed level changes. The plunging effect, turbidity current movement, and the formation of a muddy pond were simulated with a high temporal resolution to capture these fast processes in detail. In addition, the results were compared with empirically developed velocity and concentration profiles of turbidity currents. The results from the three-dimensional numerical model show an accurate replication of the observed distribution of flow velocities, suspended sediment concentrations, and deposition patterns. This study opens a frontier for the application of three-dimensional numerical models in simulating several mechanisms in reservoir sedimentation (delta migration and density currents), which may occur simultaneously. This also enables the investigation of these complex transport phenomena with high temporal resolution.