Simulated erosion using soils from vegetated slopes in the Jiufeng Mountains, China

摘要

The effects of rainfall intensity, slope gradient and vegetation cover on the intensity of runoff and rate of soil erosion were examined with simulated rainfall. All five affected soil erosion in experimental soil boxes containing Vitex negundo var. heterophylla (VN), VN with litter (VN-L), Broussonetia papyrifera (BP), BP with litter (BP-L), and a control with bare land (BL). The presence of the vegetation and litter layers significantly reduced the rates of sediment yields, the mean rate of sediment yield values of BP-L, BP, VN-L, VN and BL were 2.873 g/min, 11.264 g/min, 4220 g/min, 16.781 g/min and 21.594 g/min, respectively. The mean rates of sediment yield increased linearly with increases of rainfall intensity and slope gradient, but not beyond a certain gradient. B. papyrifera reduced sediments by 6.24 and 25.55% more than V. negundo var. heterophylla with and without litter layers, respectively. The rate of sediment yield was positively and linearly correlated with runoff shear force, with rates increasing quickly in VN, and the critical runoff shear force of BP was 0.8282 N/m(2), and VN was 0.2098 N/m(2). The results of this study will help to determine appropriate methods for reducing soil erosion. (C) 2015 Elsevier B.V. All rights reserved.