A review on mechanism of rainwater in triggering landslide

Landslide could be evaluated as a very serious issue in tropical countries due to its hazardous impact on lives and properties. One of the factors influencing to the development of landslides is the rainfall infiltration which is considered as a major triggering factor. It decreases the matric suction, increases the pore-water pressure and causes the groundwater table to rise. This paper is reviewing the mechanism of rainfall induced slope failure, the effect of rainfall infiltration, soil suction and the rise of groundwater table on slope stability. The results show high rainfall intensity infiltrates initially in a higher rate than soil permeability and develops a perched water table which induces shallow landslide. While, low rainfall intensity for a longer period is more dangerous than heavy rain for a short period. It increases the saturation of the soil and causes the matric suction to dissipate and this triggers landslide. Moreover, the review reveals that the factor of safety increases when the initial soil suction at the ground surface is high. The rise of groundwater increases the pore-water pressure and soften the slope-forming material and leads to landslide.