Effect of Grass Coverage on the Sediment Concentration in Overland Flow

Abstract

By scouring experiments, the changeable process and characteristics of sediment concentration in sloping surface with different coverage degrees and spatial locations of grass were studied. Five grass coverage degrees of 0, 30%, 50%, 70%, 90%, three spatial locations of grass (upslope, mid-slope, low-slope) and two water inflow rates of 3.2L/min, 5.2L/min were applied to a 0.5 by 4 m soil bed in scouring experiments. Results showed that the sediment concentration in overland flow obviously decreased with increasing grass coverage degree during the scouring experiments. When the grass coverage degree is over 30%, the grass can play obvious role in reducing the sediment concentration, and along with the increase of grass coverage degree the role became more and more obvious, particularly when the grass coverage degree reached to 70%. The spatial location of grass on the sloping surface has little effect on the sediment concentration in overland flow.