Numerical Simulation to Study Abnormal Tidal Ranges Along the River Course in Huangmaohai Estuary

1-dimensional and 2-dimensional ECOMSED models are respectively used to calculate the nonlinear effect and the runoff effect on the tidal wave propagation in the Huangmaohe Estuary.As it is shown in the results from the calculation,1) the nonlinear effect on the tidal level becomes more obvious when it is at high water or at low water and also obvious in the further upstream area.2) The tidal range is increased with the distance further away from the sea,when the runoff flow becomes greater above a critical volume.3) The tidal energy converges at Yamen where the jet is located and the energy dissipation rate per unit area of the river cross-section is greatest.And the energy flux across the river cross section and the energy dissipation rate become decreased in the further upstream area.It is the joint action of the energy flux and the energy dissipation that makes the tidal range vary along the river course.4) Under certain boundary conditions of the tidal level and the rivel flow,the tidal energy and the energy dissipation depend upon both the over-all morphology in the estuary and the river course morphology so that the concrete hydrodynamic features are determinative.