A PHASE-RESOLVING CROSS-SHORE SEDIMENT TRANSPORT MODEL FOR BEACH PROFILE EVOLUTION

A phase-resolving wave transformation module is combined with an intra -wave sediment transport module to calculate the on-/offshore sediment transport rates. The wave module is based on the Boussinesq equations extended into the surf zone. The vertical variation of the mean under tow and the intra-wave sediment concentrations are calculated. The net sediment transport rates are calculated, and the equation for conserv ation of sediment is solved to predict the beach profile evolution, Th e results of the present paper showed that the undertow contribution t o the sediment transport rates is not dominating in all parts of the s urf zone, even for eroding beaches, suggesting that other contribution s should not be neglected. The present model also showed that for the same offshore wave energy the time series of the oscillatory motion is important and that the effect of wave groups cannot be disregarded. ( C) 1997 Elsevier Science B.V.