Abstract: In an attempt to study the infiltration law and its effect on the stability of shallow landslide induced by rainfall, the volumetric water content and matric suction at different depths of Gufenping landslide in Nanjiang County and its adjacent areas were measured. The dynamic changes of water content and matric suction in slope under rainfall condition were examined in association with real-time rainfall data. Moreover, the slope stability was calculated by using an infinite slope model. Results revealed that the initial volumetric water content at monitoring point 2^#, which is located in the adjacent of landslide, decreased as depth increased; the initial volumetric water content at monitoring point 1^#, however, augmented as the point went deeper due to a groove on the bedrock surface of the scarp of landslide. In rainfall condition, the volumetric water content at the bedrock surface responded the most rapidly in the presence of a favorable seepage channel. In the meantime, the factor of safety reduced with the increase of depth, with the most dangerous sliding surface along the bedrock surface. Nevertheless, the factor of safety is larger than 1, indicating that the landslide is still stable at present. The research results are expected to provide a scientific basis for the forecasting, risk assessment and disaster management of shallow landslides.

Key words: shallow soil landslide, rainfall, monitoring, infiltration law, infinite slope model, stability analysis