Landslides occur when the stability of the slope changes from a stable to an unstable condition. A change in the stability of a slope can be caused by a number of factors, acting together or alone. Natural causes of landslides include:
groundwater (pore water) pressure acting to destabilize the slope
Loss or absence of vertical vegetative structure, soil nutrients, and soil structure (e.g. after a wildfire(e.g.fire in forests etc.lasting for 3–4 days)
erosion of the toe of a slope by rivers or ocean waves
weakening of a slope through saturation by snow melt, glaciers melting, or heavy rains
earthquakes adding loads to barely stable slope
earthquake-caused liquefaction destabilizing slopes
volcanic eruptions