SPATIAL DISTRIBUTION OF CROSS-SHORE SEDIMENT TRANSPORT RATE FOR BERM FORMATION AND EROSION

摘要

A 2.5-year data set of beach profiles was used to examine the characteristics of berm shape and the spatial distributions of the cross-shore sediment transport rate for berm formation and erosion. The seaward distance, x, is normalized by the distance of the investigation area, X, which is from the maximum wave run-up position, x/X = 0.0, to the position where the standard deviation of the beach profile takes the lowest value seaward of the mean shoreline position, x/X= 1.0. Analysis of the data reveals that the landward sediment transport rate for the berm formation increases from xlX = 0.0 to 0.4 and reaches a constant value toward x/X = 1.0. As for berm erosion, the landward sediment transport rate peaks at x/X =0.10 and the sediment transport rate changes in the seaward direction at x/X = 0.20. From this position, the rate decreases until x/X= 0.60.