Changes in runoff-sediment reduction benefit of slope land as influenced by use of grass strips

Abstract

The dynamic of different grass strips width effects on runoff-sediment reduction benefit are not clearly understood. Thus, we aim to determine the optimum grass strips width on runoff-sediment reduction benefits on inceptisols slopes. In this work, using a soil flume as a carrier, we analyzed the influences of flow rate and grass strips width on runoff and sediment yield, as well as determined the optimum grass strips width on runoff and sediment reduction benefit through simulated scouring experiments under different flow rates (4, 6 and 8 L/min) and grass strips widths (0.50, 0.75 and 1.00 m). The results showed that 1) the runoff coefficient increases binomial with increasing scouring time, and the runoff and sediment yield of grass strips were much lower than those of bare soil under a given flow rate. 2) Compared to the bare slope, the mean runoff and sediment reduction benefits of the average grass strips width were 27.20% and 43.66%, respectively. 3) The 1.00 m grass strips width had a great runoff-sediment benefit for controlling the soil erosion, and the runoff-sediment reduction benefit was more sensitive to changes in grass strips width than to flow rate. Therefore, we can conclude that the 1.00 m grass strips width was the optimal grass strips width for reducing the runoff and sediment yield. These results have theoretical and practical significance for preventing water and soil loss on purple soil sloping farmland.