Adaptability of Suspended Sediment Transport Model for Sandbar Migration Simulation

Adaptability of a nonequilibrium suspended sediment transport model to flow and morphological conditions was studied. Under dispersive and unsteady flow conditions, four sets of numerical simulations were conducted using a morphodynamic model. The flow fields were modeled using the Boussinesq equation and the bottom evolutions were modeled using the transport equation for the suspended load and the bed load formulae. Numerical simulations using a constant suspended parameter and variable bed load parameters within a multiple of reference values yielded very similar predictions. These similarities resulted from the adaptability of the suspended sediment transport model which considered the flow and morphological conditions; although the use of different values of bed load parameters resulted in different individual contributions to the bed load fluxes by the parameters, the suspended sediment model adjusted the suspended load flux and made total fluxes converged. The same results were observed in the bottom evolution rates. On the other hand, successful results could not be obtained in the opposite cases: with fixed bed load parameter and variable suspended load parameter.