FLOW AND BED TOPOGRAPHY CAUSED BY A SERIES OF VEGETATION ZONES ARRANGED ALTERNATELY ALONG THE CHANNEL SIDES

Abstract

Flow and bed evolution caused by a series of alternately arranged vegetation zones along the channel sides were investigated experimentally in the present paper. Because of the rise of water surface elevation just upstream the vegetation zone due to a sudden increase of local flow resistance, a secondary current is generated in the direction departing from the zone. And the locus of maximum velocity line is found to meander between each vegetation zone and its opposite side wall. The bed topography caused by this current in a movable channel is seen that a pair of both a deeply scoured portion and a deposited sand bar emerge in accordance with a generated flow field.