This study investigated the relationship between soil water content and electrical conductivity to construct a model of the shear strength of shallow landslides with electrical conductivity as the primary variable. The Babaoliao landslide site in Chiayi County, Taiwan, was selected as a case study. First, based on in-situ electrical conductivity
measurements and hydrological parameters, the study modeled the correlation between electrical conductivity and hydrological parameters. Next, the study extended the shear strength model to unsaturated soils to correlate the
shear strength model with matric suction and electrical conductivity. For empirical validation of the proposed model,this study adopted a finite-element numerical model and used the local factor of safety to assess slope stability. Slope stability analysis revealed that the shear strength of the landslide was consistent with observed variations in the local safety factor, indicating that the shear strength model with electrical conductivity as the primary variable established in this study can serve as a useful alternative to conventional hydrological assessments of landslide stability. The model proposed in this study was further extended to analyze the hydraulic properties of the unsaturated soil of the Babaliao landslide.
Key Words: shallow landslides, soil hydraulic properties, electrical conductivity, slope stability.