5Dawson E M, Roth W H, Drescher A. Slope stability analysis by strength reduction [J]. Geo technique, 1999,49(6):835- 840.
6Zhang X,Quine T A ,Walling D E. Soil erosion rates on sloping cultivated land on the Loess Plateau near Ansai, Shaanxi Province,China:An investigation using 137Cs and rill meas urements [J]. Hydrology Processes, 1998,12(1) :171-189.
7Zhang G S. Effect of straw and plastic film management under contrasting tillage practices on the physical properties of an erodible loess soil [J]. Soil & Tillage Research, 2008,98 (2): 113-119.
8Jacob W E,Rattan L. Tillage effects on physical properties of agricultural organic soils of north central Ohio [J]. Soil & Tillage Research,2008,98(2) :208-210.
9Liu B Y, Nearing M A, Shi P J, et al. Slope length effects on soil loss for steep slopes[J]. Soil Sci Soc of Am J,2000,64 (5) : 1759-1763.
10Nearing M A, Norton L D, Bulgakov D A, et al. Hydraulics and erosion in eroding rills [J]. Water Resources Research, 1997,33(4) :865-876.