Three-dimensional numerical simulation of tidal current and residual current at Daya Bay

Abstract

A three-dimensional shelf sea model(HAMSOM) is employed to simulate the tide,tidal current and residual current at the Daya Bay.The computed results agree well with the observed ones.The co-tidal chart,tidal nature,tidal ellipses of the main component and residual current are given.It is shown that the tide at the Daya Bay is mainly irregular semidiurnal.The horizontal tidal flow reciprocates obviously in the south-north direction.The flow speed of ebb tide is greater than that of flood tide.The maximum flow velocity of M2 tide component is 25.3 cm·s-1.The flow is affected by the topography,with the larger flow speed occurring at the narrow area among the mainland,the Dalajia island and the Huangmaoshan island and the smaller one near the coast.The horizontal velocity changes little vertically.As the residual current within the bay is relatively small in summer,the self-purification capacity of this sea area is weak;whereas it is stronger in winter with the stronger current fields.