A STUDY ON THE DEPENDENCE OF THE MIGRATION RATE OF BOTTOM SEDIMENT ON DIFFERENT EQUILIBRIUM BEACH PRROFILES

Abstract

The relation between the migration rate of sand and water particle velocities in the two phase flow of a solid-liquid involving suspended sediments in the surf zone has not been satisfactorily understood yet. This study presents the effects of the different equilibrium beach profiles on the temporal and spatial distribution of migration rate of suspended sediments in the two phase flow of a solid-liquid, where sediments at the flow bottom are suspended under breaking waves. As a result, we have found that the migration rate of sediments averaged over a wave period between Type I and Type II of the beach profiles change. Type I has showed larger flow velocities than Type II in the entire region, particularly under wave crests. The migration direction of sand particles in Type I is the same as that in Type II. Specially, the migration direction is shoreward near the wave crests and seaward near the wave troughs in both types.