Mass movements can have devastating effects on the infrastructure and human activities. A landslide is a dynamic geomorphic process during which the loose material on the surface moves downslope under the infuence of gravity. Besides the rainfall can increase the amount of water into the slope surface which can trigger the landslides. Human beings can also trigger landslides by activities such as construction, farming practices and mining.

Landslides are a common form of slope erosion in areas of stream incision and of tectonic uplift. Landslides are responsible for forming the initial slope upon which other processes can then operate. Landslides usually occur after a heavy rainstorm. In a saturated soil, the water has the effect of floating the soil, since the weight of the soil and subsequently the friction is decreased at the failure plane.

   Stop and Think!

What are the effects of landslides on human activities? What are the likely effects of the process shown in the pictures below?