Experimental Study on Influence of Vegetation Coverage to Soil Infiltration and Runoff-Producing of the Loess Plateau Region

The paper studied the influence of the variations of vegetation coverage to the soil moisture content,slope infiltration and runoff production through field artificial simulated rainfall and provided support for revealing the mechanism of soil erosion and sediment production under the actions of vegetation. The outcomes show that a) under the different conditions of vegetation coverage,the soil moisture content of top soil before and after rainfall has great difference. The growth range will be increased along with the increase of vegetation coverage and the influence of rainfall to the soil moisture content of deep layer will be more remarkable along with the increase of vegetation coverage; b) the influence of vegetation cover to the initial infiltration rate and limiting infiltration rate is obvious. The higher the vegetation coverage is,the greater the limiting infiltration rate and the shorter time of achieving the statement of constant infiltration will be and; c) comparing with uncovering slopes,the slope with grass has notable effect of runoff reduction. The runoff-producing coefficient has the trend of reduction along with the increase of vegetation coverage. The reduction trend of the coefficient will be more notable when the vegetation coverage reaches to more than18%. But under the conditions of rainstorms,even if the vegetation coverage reaches to more than 50%,the time of runoff production is still shorter.