a) Sheet erosion: Removal of soils in thin layer

b) Rill erosion: Advance stage of sheet erosion removal of soils from small and shallow channels.

c) Gully erosion: Advance stage of rill erosion.

• Gullies are formed when many rill erosion joined (>30 cm depth).
• It is widely accepted that there is a great deal of mass wasting of soils in the Himalayas which natural induced.
• Ramsay (1986) reviewed the soil losses from the different types of and concluded that erosion is unlikely to be serious on forestland with a small amount of cover.
• It is likely to serous where the land had been converted to grassland and heavily overgrazed. In those cases, the rate of soil loss resulting from uncontrolled de-vegetation and severe gulling was several times higher than any other forest.
• Normally, there is 3 million kg of soil included up to 30 cm depth in one hectare of land (root zone depth).
• 5 to 10 tones of soil is removed from every hectares of well managed land area every year.
• The consequences of soil erosion are severe and clear which national economy in many ways.

Brian Carson (1985) mentioned the following effect of soil erosion.

a) Erosion loosed top-soils from the cultivated and grazing land as a result of which soil fertility declines and reducing productive capacity of the affected land.

b) Landslides cause serious destruction of land, irrigation systems, roads and foot trials.

c) Erosion brings sediment loads to the river which reduces storage capacity of reservoir, siltation of irrigation channels and damaged the water controlled structures and often changes the course of river.