Sediment Trapping from Hyperconcentrated Flow as Affected by Grass Filter Strips

Abstract

To evaluate the effect of vegetative filter strips on sediment trapping, the spatial distribution of deposited sediment, and the size distribution of deposited particles from hyperconcentrated flows, a simulated grass filter strip experiment was conducted with plastic grass using an adjustable slope steel flume. The simulated vegetation cover was 36%, and the inflow sediment concentrations applied were 147, 238, 320, and 429 kg m−3. The sediment concentration in the outflow, and the sediment particle size were determined. The results showed that the grass filter strips trapped most of the sediment from inflow at low sediment concentration. The deposition efficiency decreased with increasing sediment concentration, being 55.2% and 15.7% in the 147 and 429 kg m−3 sediment treatments, respectively. Most of the deposited sediments were distributed in the upper flume. In addition, the grass filter strips mainly trapped the coarse sediment (particle size > 10 μm).