Author(s): Chang-Lae Jang
Linked Author(s): Chang-Lae Jang
Keywords: Riparian vegetation; Sediment sorting; Geomorphic change; Mixed sediment
Abstract: The study investigates the changes of channel and sediment sorting in the bed with vegetation. The sediment channel is irregular, and the amount of the sediment discharge decreases as the vegetation density increases. The bed elevation changes irregularly, and the sediment particle diameter on the river bed surface decreases due to vegetation. With the increase in the vegetation density, the dimensionless median particle diameter on the river bed surface decreases. The sediment is captured by the vegetation zone or deposited due to the boundary layer flow between the vegetation zone and the main flow. The changes of the flow in the vegetation zone result in an irregular distribution of sediment particle diameters on the surface layer. As the dimensionless median particle diameter of the river bed sediment decreases, the shield effect also proportionally decreases. With the increase of the vegetation density, the shield effect on the river bed's surface layer increases, which is consistent with the decrease of the sediment discharge at the downstream end of the experimental channel.
Year: 2020