Study On Regulation For Tidal Estuary Inlet By Mathematical Simulation

The current flowing in estuary controlled by stream and tide is very complex. As one important composed part in estuary, bifurcated estuary has not only the commonness of estuary but also its characteristic. The regulation for bifurcated estuary is differ from that of single river, and the bifurcated river with conjoint water area are to be considered to systems analysis as whole. Based on the hydrodynamic analysis to the estuary, an general estuary inlet is proposed by bifurcated characteristic with single bifurcating and symmetrical distributing.The current flowing is simulated by the mathematical model after regulating or dredging in the estuary inlet. The calculation shows, a pair of spur dikes can only increase the flow velocity near area, but the flow direction and the re-circulation length are changed more than ever. The flow velocity could be improved in the regulated inlet by series spur dikes, and the flow direction's change is very little, but the infection to discharge ratio is more large. The dredging can increase the depth of regulated inlet directly, and the infection to discharge ratio is very little, but the flow velocity isn't improved evidently. Regulating increases the flow velocity in part of the estuary inlet, but dredging could improve the ability of crossing flow. When regulating and dredging applied coexistent, it has the advantage of regulating and dredging and makes some disadvantage weakened. The water flow is concentrated to main channel from river beach, and the flowing ability is improved after the river bed dredged. As a result, the method of regulating and dredging is one better way for the estuary inlet, with river bed deepened, changing on discharge ratio little and increasing to flow velocity clearly.