ABSTRACT: Rainfall-induced slope failures are common problems in steep residual soil slopes in the tropics.
The characteristics of water flow, pore-water pressure changes, and shear strength of soils are the main
parameters associated with slope stability analysis involving unsaturated soils which are directly affected by
the flux boundary condition (infiltration, evaporation) at the soil-atmosphere interface. Procedures for slope
stability analyses considering unsaturated-saturated soils as an integral system are presented. The paper also
highlights procedures and the importance of characterizing soil properties, flux boundary conditions, spatial
and temporal variability of pore-water pressures and instrumentation for slope stability assessment. It has also
been shown through examples how these procedures can be used to generate stability assessment charts for
local slopes under local environmental considerations