降雨引起的滑坡发生在陡峭的斜坡上，原因是水的渗入和随后的孔隙压力和土壤的抗剪强度变化。水是造成边坡破坏的主要因素之一，容易软化表面材料，降低强度，增加孔隙水压力和对边坡稳定性的影响。如果土壤处于不饱和状态，则是由于降雨入渗造成的。渗透通常通过计算一个无限大的斜坡的因素、安全或临界深度来解决。一些学者指出，自然坡度最严重的环境因素是持续的暴雨，这很容易导致滑坡的侵蚀和崩塌。与此同时，雨水的渗透会促进地下水位的升高，导致边坡失稳。侵蚀和孔隙水压力之间的区别是说明土壤侵蚀发生的层的去除土壤和孔隙水压力是描绘的永久写点这表明最小点的土壤能够成立.
地下水在边坡的副作用包括:水压力作用于垂直骨折,导致水平插入时,导致斜率向下推,孔隙水压力效应作用于浅层滑动面,它减少了有效应力和摩擦表面,地下水作用于薄膜矿物质特别是粘土矿物会产生润滑作用。然后它会导致滑动，它将改变土壤和岩石的物理和化学性质，使岩石和土壤退化，降低强度，最终影响坡的稳定性.
Rainfall induced landslides occur on steep slopes owing to water infiltration and subsequent changes in pore pressure and shear strength of the soil. Water is one of the main factors causing slope damage, and it is easy to soften the surface material and to reduce the strength, then increase the pore water pressure and the effects on the slope stability. If the soil is in the unsaturated state, the failure is due to rainfall infiltration. The infiltration typically addressed by calculating the factor, safety or critical depth for an infinite slope to seepage. Some scholars have pointed out that the most serious environmental factors to the natural slope are persistent rainstorms, which can easily lead the erosion and collapse of the slope. At the same time, the infiltration of rainwater will promote the elevation of groundwater level causing the instability of the slope. The distinction between the erosion and the pore water pressure is illustrated that soil erosion takes place by the removal of the layers of the soil and the pore water pressure is depicted to be the permanent writing point which indicates the minimal point at which the soil is able to hold water.
Adverse effects of groundwater on slopes include: water pressure acting on vertical fractures and resulting in horizontal thrusts, which lead the slope to be pushed downward, the pore water pressure effect acting on shallow sliding surfaces that it reduces the effective stress and friction of surface, the ground water acting on the sheeting minerals especially the clay minerals will produce the lubrication action. Then it will cause sliding and it will change the physical and chemical properties of soil and rock, making rock and soil deterioration, reducing strength and finally influencing the stability of the slope.