7Fell R. Landslide risk assessment and acceptable risk [ J]. Canadian Geotechnical Journal, 1994, 31 (2) : 261 - 272.
8Varnes, D. J. 1978. Slope movement types and processes [R]. In Landslides: analysis and control. Edited by R. L. Schuster and R. J. Krizek. National Research Council, Spe- cial Report 176, pp. 11 -33.
9Reid, S. G. 1989. Risk assessment research report[ RI. School of Civil and Mining Engineering, University of Syd- ney, Australia. pp. 1 -46.
10United States Bureau of ReclamationL S]. 1989. Policy and procedures for dam safety modification decision - making. U. S. Bureau of Reclamation. Denver, Colo.