Experimental Study on River Channel's Formation and Change Process of on the Surface of Delta Deposition

Abstract

Experimental study on river channels formation and change process with two different constant flows 2.45L/s and 4.9L/s that which come from mountains and into delta depositions surface, based on sediment supply 15.72kg/h at the water inlet. After 964h experiment, research on the study shows as follows: with 2.45L/s flow, on the surface of delta depositions forming process the channel appears as straight, braided, micro-bend and meandering form. The first formation processes of delta deposition are straight and braided river which appeared alternately every 50h on the surface. When time goes on the delta get longer and braided streams branch of the shunt decrease gradually, that made the channel appeared with slightly curved form. Combined with that flexural radius gets bigger because of the outer bank erosion of slightly curved channel backed off, finally the meandering channels presented. With 4.9L/s flow, the formation processes gave priority of braided river, which appeared every 15h cycle, following the aggravate of eroding in floodplain and scouring in main channel, the river pool board-shallow comes with the main-flow swing, the channel existed as slightly curved form, and appears two sides of deposition. Finally analysis and research the channel cross-section morphological and longitudinal slope. In conclusion, the delta depositions surface channel existed as micro-bend of no branch with single strands, under the constantly water and sediment conditions.