A spatially distributed physically based slope stability model combined with a hydrological model is presented and applied to a 350-km2 area located in Dhading district, Nepal. Land slide safety factor maps are generated for five cases, including three steady state conditions assuming either completely dry soils, half saturated soils, or fully saturated soils, and two quasi-dynamic conditions, i.e. soil wetness resulting from storm events with, respectively a 2 or 25-year return period. For the quasidynamic cases, two methods are used, one based on accumulation of groundwater flow from upstream areas, and the other on accumulation of soil water from direct infiltration.
R. L. Ray Æ F. De Smedt