Landslides related to Earth system
A landslide is the rapid sliding of large masses of bed rocks or regoliths. Groundwater increases the weight of the rock or the soil which contains it. Sometimes a mass of earth saturated with water slides down a hill slope causing landslides. There are many varieties of landslides depending on the mass, sliding and distance transversed by it. Those which move only through short distances are called “slumps”.
When millions of cubic of material moves through thousands of feet of distance, they are known as Rock slides. When under gravity rock material falls down from high ridges, rockfall occurs. A landslide covers a very wide range of gravity dominated processes that transport relatively. Dry earth materials down slope to lower ground, with displacement achieves by one or more mechanisms : falling, flowing and sliding.
The landslide hazard causes sever loss of life, injury damage to property, destruction of communication network and loss of precious soil and land. The occurence of land slides is declining all over the world. Due to greater scientific understanding and public awareness in many areas, the mounting pressure of population at the base of slopes, canyons and unstable borders of plateau have led to an increase in dangers due to landslides. Landslides are universal phenomena.
Factors responsible for landslide.
Landslides due to slumping may occur due to construction of settlement built on filled up land that suffers from poor compaction or engineering . In forests, timber harvesting may negatively affect slope stability. Tractors in general cause immense damage as run off follows the wheelings. Apart from the above mentioned forces the. causes of slope failure may be distinguished as :-
1. Immediate causes such as vibrations Earthquake tremors heavy precipitation and freezing and thawing.
2. Long term causes such as the slow and progressive steepening of the steps.
Effects of the landslides
Landslides produce great scars on the sides of mountains. Sometimes give a rippled shape to the hill side on account of mixed rock slumps on the back slope. Landslides and Rock slides are of frequent occurrence in many mountains. In 1957, such a huge landslide came down in Kashmir. Recently, a landslide in TehriGraham region occured due to cloud burst. Most of the mountains and land are falling down due to heavy rainfall mostly in soily region.