EFFECT OF STOPPING FLOW IN ONE BRANCH OF BIFURCATED TIDAL ESTUARY ON HYDRODYNAMIC SEDIMENT ENVIRONMENT

Taking stopping flow in the South Branch of Oujiang Estuary as an example, tidal current and sediment problems related to stopping flow in one bifurcated branch of a complex tidal estuary are studied in this paper. A numerical model of tidal current and sediment movement under the combined action of wave and current are set up with irregular triangular grid. The model is verified with in situ data, and the results show that the calculated water elevations at 19 stations, currents, suspended sediment at 19 vertical lines and seabed evolution are all in good agreement with measured data. This numerical model is applied in the tidal current and sediment movement simulations in stopping flow transport through the South Branch of the Oujiang Estuary and the feasibility to cut off the flow in the South Branch of the Oujiang Estuary is demonstrated by numerical simulation experiments. The results show that flow cutoff in the South Branch by heightening the present submerged dyke is technically feasible as far as its impact on hydrodynamic sediment environment is concerned.