Field measurements of on-offshore sediment transport rate in the swash zone

Using a vertical array of four streamer-type traps, the on-offshore sand transport rate was measured in the swash zone on a natural beach, The vertical distribution of the onshore transport rate showed that the maximum occurs in the bottom layer and that the rate gradually decreases with distance from the bed. The corresponding distribution for the offshore transport rate also indicated that the transport was concentrated in the bottom layer with an even sharper decrease in the rate going upwards. The total onshore and offshore transport rate integrated in the vertical direction were proportional to the second power of the onshore and offshore current velocity, respectively.