LATERAL BED-LOAD TRANSPORT AND SORTING NEAR VEGETATION ZONE ALONG SIDE WALL

Abstract

In fluvial stream with vegetation zone along side wall, low frequency fluctuation of transverse velocity brings alternate lateral bed-load transport. Since the bed shear stress near vegetation zone changes rapidly in the transverse direction, net lateral bed-load remain after the average of one period of fluctuation. It causes longitudinal sand ridge formation; furthermore it accompanies a longitudinal sorting in case of graded materials. In this paper, flume experiment is conducted to demonstrate the above phenomena, and they are explained by using of the model of non-equilibrium bed-load transport.