Mapping Slope Failure Potential Using Fuzzy Sets

This paper documents a low-cost, qualitative evaluation scheme using a fuzzy set analysis for mapping slope failure potential (SFP). Four categories of factors affecting stability of natural slopes, i.e., geology, topography, meteorology, and environment, are considered. Each category involves two to five factors, and a total of 13 factors is used in the proposed evaluation scheme. A set of evaluation criteria was established for each adopted factor. In the proposed evaluation scheme, slope failure potential is assessed and recorded in linguistic terms based on the established criteria. The linguistic data or information obtained from the assessments is represented and processed using fuzzy sets. In this study, the analysis or computation involving fuzzy sets was performed using the Monte Carlo simulation technique. An SFP index to measure the slope failure potential is defined. Based on the computed SFP values for a large number of subareas or cells selected for an area studied, an SFP map can be developed. An example application is presented to demonstrate the method. The SFP map developed in the case study seems to be able to correctly predict the slope failure potential of the area studied.