In this paper, combining the Geographic Information System (GIS) spatial analysis function with an improved Hovland''s 3D slope stability analysis model, a new GIS based 3D deterministic model is developed. Assumed the initial slip as ellipsoid, the 3D critical slip surface in the 3D slope stability analysis is performed by the means of a minimization of the 3D safety factor by using Monte Carlo random simulation. In the analysis program that is programmed by Microsoft Visual Basic (VB) and GIS components, taking the advantage of GIS spatial function, the input data for random selected .slips stability analysis can be easily processed and managed; the results can be easily showed and reclassified too on the spatial map.
It is rational to use three-dimensional (3D) deterministic model to study slope stability because all slope failures have a three-dimensional geometry, which varies in space even along short distance. In the recent years, Geographic Information System (GIS), with its excellent spatial data process ability has attracted great attention in natural disasters assessment. GIS is a system of hardware, software for data capture, input, manipulation, transformation, visualization, combination, query, analysis, modeling and output. GIS provides strong functions in spatially distributed data processing and analyzing. At same time, using GIS can easily and effectively perform the analysis of slope stability if a GIS based geotechnical analysis model can be used.