MODELING ESTUARIAL COHESIVE SEDIMENT TRANSPORT

Abstract

Cohesive sediment related problems in estuaries include shoaling in navigable waterways and water pollution. A two-dimensional, depth averaged, finite element cohesive sediment transport model, CSTM-H, has been developed and may be used to assist in predicting the fate of sorbed pollutants and the frequency and quantity of dredging required to maintain navigable depths. Algorithms which describe the transport processes of redispersion, resuspenslon, dispersive transport, settling, deposition, bed formation and bed consolidation are incorporated in CSTM-H. The Galerkin weighted residual method is used to solve the advection-dispersion equation with appropriate source/sink terms at each time step for the nodal suspended sediment concentrations. The model yields stable and converging solutions. Verification was carried out against a series of erosion-deposition experiments in the laboratory using kaolinite and a natural mud as sediment. A model application under prototype conditions is described.