Experimental Study On Erosion Rule Of Distrucbed Sandy Soil By Simulated Rainfall

This article used research method of simulated rainfall and slope variable steel tanks, according to the high sandy soil areas in Jiangsu Province, studied water erosion rule of disturbed sandy soil under different slope, different rainfall intensity, different rainfall amount. and different vegetation coverage conditions, research has made some progress to provide evidence of piled up way and protective measures of the disturbed sandy soil. The main results are as follows:(1)Sediment concentration increased rapidly in the beginning stage of rainfall, then reduced quickly. Sediment concentration reaches stable in the later rainfall stage under rainfall intensity of 50mm/h and 65mm/h, in the rainfall intensity of 80mm/h, rill erosion has happened in the later rainfall stage, appeared the sediment concentration increased.(2)With increasing of slope, the runoff increases. There is a critical erosion slope between erosion amount of sandy soil and slope gradient, with increasing of slope gradientl, the erosion amount increases when the slope gradient lower than critical erosion slope, when the slope gradient higher than critical erosion slope, with increasing of slope gradientl, the erosion amount decreases. When RI lower then 80mm/h, the critical erosion slope is between 20°and 26.5°;when RI higher then 80mm/h, the critical erosion slope is more then 26.5°(3)When the rainfall amount equal, runoff amount increased as the rainfall intensity increased, as the rainfall intensity increased, the precipitation infiltration amount decreased. With the rainfall intensity increase, increasing amount of runoff also increase. Runoff volume and soil erosion amount have linear positive correlation with rainfall amount. Soil erosion amount have linear positive correlation with runoff volume.(4) Rainfall intensity has impact to soil erosion pattern, soil erosion intensity(soil loss amount and runoff volume will enhance when rainfall intensity increase.Along with the increasing of rainfall intensity, the soil erosion amount and increasing rate of erosion soil increased. The increase amplitude of total sediment concentration has a positive correlation with the slope. The increase amplitude of total sediment concentration increase with the rainfall intensity increase, show that intensity of erosion will increase as the rainfall intensity increase.(5) Vegetation can greatly reduce runoff and soil erosion. Among different plants, those plants which have bigger aerial parts, wider blades, more developed roots can reduce runoff and soil erosion better.