1.Institute of Mountain Hazards and Environment,CAS & MWR,610041,Chengdu;2.State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Institute of Soil and Water Conservation,CAS & MWR,712100,Yangling,Shaanxi;3.Graduate School,CAS,100039,Beijing:China
Abstract：To establish a standard for preventing soil erosion on cultivated land,soil scientists in USA proposed firstly the concept of Soil Loss Tolerance,then the concept has been applied for evaluating soil erosion risk in a watershed or a region.The concept of soil loss tolerance has been widely used over the world as well as in China.As progressing of researches in soil erosion and relevant subjects,particularly,global changes,the appearing of concepts of sustainable development and rivers health,the shortages of "soil loss tolerance" in scientific concept as well as in practice have gradually appeared.In this paper,the history of the soil loss tolerance is briefly introduced,then the shortages of the term are discussed,finally the concept of reasonable soil loss is introduced and the principle and methods for determining its standard are proposed.
2007, Vol. 5 
