Three Dimensional Numerical Modeling of Cohesive Sediment Transport in a Shallow Oxbow Lake

This paper presents the development and application of a three-dimensional numerical model for simulating the cohesive sediment transport in water bodies where both currents and wind-driven waves are important. The model was verified by a simple test case with an analytical solution (nonconservative tracer in a prismatic channel with uniform flow) and applied to Deep Hollow Lake, a small oxbow lake in Leflore County, Mississippi. The model produced predictions within 2% of the analytical solution. The bottom shear stresses induced by currents and waves were calculated, and the processes of resuspension, deposition and settling were considered. The primary forces associated with sediment transport were caused by wind-induced currents and waves. Simulated sediment concentrations were compared with limited field observations available, with generally good agreement. Simulated concentrations for a scenario with wind-driven waves were about one to three times greater than for a simulation without wind-wave processes.