Abstract

At present, soil erosion is one of the global disasters, which seriously threatens the existence and development of human being. The Loess Plateau of China is a famous critical soil loss area in the world. This paper comparatively analyzes the influence of vegetation coverage on runoff production and sediment yield on bare sloping land and sloping land covered by typical vegetations (Platycladus orientalis, Pinus tabulaeformis Carr and Acer truncatum Bunge) on the Loess Plateau. Artificial rainfall simulating in a laboratory and a self-designed soil channels with adjustable gradients are used to provide the experimental data. The results show that the arbor tree is not the major determinant of soil erosion compared to the gradient. If the rainfall intensity is known, the gradient of a slope determines the scale of the runoff, the power of the runoff on the slope, and the sediment yield on the slope. The slope is one of the major determinants of slope erosion. When the gradient is quite big, the role of litters should be emphasized. This is because litters reduce the splash erosion of rainfall drops and the flush erosion of the runoff on the slope, thereby reduce soil erosion to a minimum possible level.

Keywords: Loess Plateau; vegetation coverage; sloping land, runoff production and sediment yield