Soil Erosion is one of the major problems faced by many countries. A major part of the total land available to us is lost due to cultivation, while a large gets depreciated every year due to Water Erosion and Wind Erosion. Soil Erosion is a natural process of soil depreciation. It depreciates the quality, structure, salinization, and organic matters of the soil. Topsoil has the highest quantity of organic components, composed of mineral particles, water, air, etc. Due to Soil Erosion, the topsoil gets eroded and removed among all other layers of the soil. 

Soil erosion composes of three parts- detachment, movement, and deposition. Detachment is when the topsoil is detached from the other layers of the soil. Movement is the process of the topsoil moving into another region. And, Deposition is the outcome of Movement- where the topsoil deposits itself after movement. 

One must keep in mind that Soil Erosion is not always Natural, sometimes it is the result of human degradation of forests, mismanagement, etc. 

Water Erosion

Soil Erosion of Water is mainly caused by Rainfall, which is natural. However, it has two sources, namely, raindrops and surface flow of water. Raindrops fall from the sky, hence, this source is a vertical source of water erosion. While, the surface flow flows horizontally- causing the topsoil to move and deposit in another region. However, the raindrops detach, move, and deposit the topsoil into another region. Soil Erosion in this form has various forms. These forms are: 

• Rill Erosion: Rill Erosions channel the detachment and movement of the topsoil, and smoothen out the raindrop glow onto the ground. 
• Splash Erosion: Splash Erosion is the process in which the soil particles get removed because of Rain Drops.
• Gully Erosion: Gully Erosions are the form of soil erosion in which Gullies emerge in the grounds due to the heavy rainfall, speedy flow of water on the ground. Gullies are so deep in the surface level that they can divide the piece of land into different portions. 
• Ravines Erosion: Ravines Erosion is the upgraded version of Gully Erosion. It is deeper than the Gullies formed due to heavy rainfall, the speedy flow of water on the ground. 
• Slip Erosion: Slip Erosions are common in places with high altitude mountains and heavy rainfall, causing sloppy lands. The ultimate effect of these forms of erosion is an Earthquake or very heavy rainfall. 
• Stream Bank Erosion: Stream Bank Erosion takes place when the water stream changes its direction and cuts the soil, making caves in the swollen river banks.

Wind Erosion

The arid and semi-arid regions are the most commonly affected regions of Erosion by Wind. These regions commonly do not have any kind of vegetation and the velocity of the wind is also high. Wind Erosion happens in such a way that the displaced soil forms a dune. This happens due to the high velocity of the wind in the region. The formation of these dunes makes the ground unfavourable for farming and cultivation. 

The erosion of soil due to wind causes three different types of movement of Soil. These are-

• Suspension: The movement or transportation of tiny dust particles in the air is known as Suspension. These tiny particles are often smaller than 0.1 millimetres in diameter. 
• Saltation: When the soil moves in a series of small bounces by the Wind then it is known as Saltation. This is the most common form of Soil Erosion by Wind. These collusion particles are 0.1 to 0.5 millimetres in diameter. 
• Surface Creep: Due to the pressure that creates during Saltation, the huge soil particles slide and rolls along the surface, known as Surface Creep. These heavy particles are 0.5 to 3.0 millimetres in diameter.

Mechanical Control

There are various ways of mechanical control of Soil Erosion. These ways include Graded Bunds, Bench Terracing, Trenches, among others. 

• Graded Bunds: These bunds are constructed in areas having heavy to average annual rainfall with 2 to 6 per cent sloping in its structure. These bunds have embankments built in the lower end of the channel through which the soil evacuates. 
• Bench Terracing: This method consists of the building of step fields along contours with half-filling and cutting. It is the most popular method used. These are built-in lands with sloping between 16 to 33 per cent. 

Trenches: These are adopted regions having heavy rainfall and slopping of more than 33 per cent. In the trench side of the bunds, various kinds of plantation in done.

Conclusion

As we know Soil and Water are two of the most important elements of survival. These elements govern various processes of life on Earth. The soil fertility is also maintained by a balance between these two elements. However, in this mechanism of soil erosion pdf, we have come across ways in which the quality and quantity of soil in a region is impacted by Water and Wind. Therefore, Soil Erosion is one of the major problems faced by many countries. It is a natural and sometimes human-made process of depreciation of Soil. Hence, the Conservation of Soil is a very important practice to increase the production outcome.