Effects of near-surface soil water conditions on soil erosion process
ZHANG Yu-Bin-；Zheng-Fen-Chi
1.State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,CAS & MWR,712100,Yangling,Shaanxi;2.Graduate School of Chinese Academy of Sciences,100039,Beijing;3.College of Plant Science,Jilin University,130062,Changchun;4.College of Resources and Environment,Northwest A & F University,712100,Yangling,Shaanxi:China
Abstract：In this paper the effects of near-surface soil water conditions on soil erosion was studied,especially for water saturated soil,using rainfall simulation experiment.The results showed that difference of soil texture had great effects on soil infiltration,and runoff process.Under the same soil texture,as antecedent soil moisture increased,infiltration rate decreased and runoff intensity increased.With the increase of antecedent soil water content,the time of runoff occurrence brought forward,runoff discharge and soil loss increased.For Ansai Loess soil,runoff discharge from soil moisture saturated condition,75% of the saturated condition of soil moisture,and 50% of the saturated condition of soil moisture were 2.5,2.2,and 1.3 times higher respectively,than that from 25% of the saturated condition of soil moisture.As compared to 25% of the saturated condition of soil moisture,soil loss from soil moisture saturated condition,75% of the saturated condition of soil moisture,and 50% of the saturated condition of soil moisture were 50,25,and 1.3 times greater,respectively.For Yangling Loutu soil,runoff discharge from soil moisture saturated condition and 50% of the saturated condition of soil moisture were 1.1 and 1.0 times higher,than that from 25% of the saturated condition of soil moisture.As compared to 25% of the saturated condition of soil moisture,soil loss from soil moisture saturated condition and 50% of the saturated condition of soil moisture were 6.5 and 2.0 times greater,respectively.During rainfall process,as antecedent soil moisture increased,the time of rill erosion occurrence was earlier and rill erosion increased.
2007, Vol. 5 
