LANDSLIDE SUSCEPTIBILTY ZONATION MAPPING USING GIS FOR IDUKKI REGION

Abstract

When weathering causes a rock to crumble and decay, the shabby material, wet with rain water, May float due to gravity.The phrase "land slippery" denotes to a rapid downhill slide movement of rock rubble. They may grow on any piece of ground if the soil, moisture, and slope conditions are rig ht. Landslides are an important part of the earth science activities on the surface of the planet and for happening of those when he condition of the soil is good and moisture contain is maintained and angle of slope must be maintained .Due to landslide failure of slopes, failure of earth surface and flow of mud, flow of boulders, can happened .the main factor of the movement is due to either earthquake which shakes the earth surface and movement of mass can happened and it could occur due to when deep excavation could have been made for the construction of various structures like buildings and it could happen because when the precipitation is heavy and its happening for long duration like what happened in Idukki in 2019. Water is not only the factor for landslide or movement of slope but weathering of rocks plays a predominant role in landslide .shear strength of the rocks is reduced due to weathering. Many researchers have found that the main reason is weight of building and their slope which act downwards due to gravity is one of the main reason for movement .to prevent the movement of mass some resisting force is applied which is in the opposite direction of friction angle and when the earthquake is for long duration the forces is automatically reduced for different kind of landslide the movement speed will be different its depend on the weight of the mass movement.