Abstract: Alongshore sediment transport rate is usually produced by sediment carrying capacity of waves and alongshore current velocities based on energy principle.For general sandy coast with steep slope and narrow wave breaking zone,tidal current in the breaking zone is often ignored since it is much smaller than alongshore current.On the sandy-silty coast,which has gentle slopes,nearshore wave height and breaking depth are large and make relative wide breaking zone during storm surge,while nearshore tidal currents...