The removal of soil at a greater rate than its replacement by natural agencies (water, wind etc.) is known as soil erosion.
Type of Soil Erosion –
- Wind erosion
- Sheet erosion
- Rill erosion
- Gully erosion
Winds carry away vast quantity of fine soil particles and sand from deserts and spread it over adjoining cultivated land and thus destroy their fertility. This type of erosion is known as wind erosion.
It takes place in and around all desert regions of the world.
In India, over one lakh kilometers of land is under Thar Desert, spread over parts of Gujarat, Haryana, Punjab and Rajasthan states. These areas are subject to intense wind erosion.
Water when moves as a sheet takes away thin layers of soil. This type of erosion is called sheet erosion. Such type of erosion is most common along the river beds and areas affected by floods. In the long run, the soil is completely exhausted due to removal of top soil and becomes infertile.
The removal of surface material usually soil, by the action of running water. The processes create numerous tiny channels (rills) a few centimeters in depth, most of which carry water only during storms.
When water moves as a channel down the slope, it scoops out the soil and forms gullies which gradually multiply and in the long run spread over a wide area. This type of erosion is called gully erosion.
The land thus dissected is called bad lands or ravines.
In our country, the two rivers Chambal and Yamuna are famous for their ravines in U.P. and M.P. states.
The controlling factors in the last two types of erosion are the velocity and amount of surface run off, the erodability of the soil, nature of slope, the texture and structure of the soil, nature of precipitation and vegetation cover.
The speed and frequency of winds or dust storms and vegetation cover are the controlling factors in wind erosion. Seawaves are responsible for eroding soils along the coasts formed by weak rocks such as limestone etc. This type of erosion is wide spread along Kerala coasts.
Substantial soil erosion is also caused by changing river channels and snowfall specially in river basins and hilly regions.
The removal of soil material naturally or by human action is called soil erosion.
Bibliography : NIOS Geography Book
Reference : http://www.nios.ac.in