Study On Soil Erodibility Of Purple Soil Under Rainfall Simulator

Owing of various factors includes nature, human behavior, a wide range of soil erosion happened in the purple soil hilly land in the south of China has not only been a remarkable symbol of ecological environment degeneration but also been a main factor that limits the local economy development and the social improvement. The long-term researches and management practices have showed that deeply knowing and correctly evaluating the soil erodibility in one region are considered as a vital foundation for reasonably using and managing the soil resources as well as a main basis for selecting the appropriate soil and water conservation measures and preventing soil degradation. In this these, purple soil which has a high soil fertility in Chongqing served as the research subject. Based on the artificial rainfall Simulator test and the physicochemical properties tests of soil sample, the test methods of K value of soil erodibility, influential factors and fluctuation rule have been significantly discussed and the regression model of erodibility factor K which bases on the parameters of soil properties. This study has been done in order to deeply know the principle of soil erosion, the evaluation of soil erodibility and the forecast in water erosion. As a knotty point of soil erosion discipline in recent years, the research in this these is significant for eroded environment control measure in purple soil region and forecast in water erosion. The results showed as follows:(1) The intensity of rainfall simulator impacted the sedimentation indicator,and its transformation tendency had the same way with the transformation tendency of the rainfall intensity.After 21min of rainfall sedimentation statistics process mutaled,.and sediment yield ratio changed from 0.021Kg/min to 0.067Kg/min.We deemed that rill erosion tacked place on this moment.The splash erosion under different intensity of rainfall simulator made the surface of purple soil unstable, so the process of crust-demolition-crust rotated,which made the infiltration ratio of water be variation.It also impacted the process of runoff,and its outputs at 0.8mm/m².(2)The fabricate among rainfall kinetic energy E,max-rainfall intensity in 5min,10min,15min,30 min had significant linear correlation of soil erosion.The results showed that the rainfall erosivity factor R =∑ EI₅ was better suitable for our study.(3)Soil erodibility factor K was measured under field micro-plots and K-nomograph .We also...