Sheet erosion or also commonly known as sheet wash can be defined as the washing off the soil surface in thin layers as a result of rainfall. Soil erosion occurs in a wide area mostly in the coastal and flood-prone areas. It has also been found in hillslopes and beaches. The amount of damage caused by sheet erosion mainly depends on the amount of rainfall and force of the wind.
Here, we have provided a piece of detailed information on which explain sheet erosion and the major causes of sheet erosion.
The sheet erosion definition provided by us will thus help the students be familiar with the process of erosion and can also be referred for their exam preparation.
Types of Sheet Erosion
The occurrence of sheet flow or erosion in flood-prone areas and coastal plains have become common these days. Any form of irregularity and unevenness may be more prone to sheet erosion. Sheet erosion is commonly found in unconsolidated soils such as bare grounds, newly ploughed soils and beaches.
Some of the major types of sheet erosion that takes place every year are - Rill Erosion, Gully Erosion and Streambank Erosion. Among all the four types of erosion, sheet and rill erosion causes more damage to the soil.
Rill Erosion and Gully Erosion
Rills can be defined as the drainage lines which are shallow and are not more than 30 cm deep. They are often formed in sunken water lands and depressions and commonly cause erosion in lands with loose soils. For example, agricultural soils, newly cultivated soils and overgrazed soils. Rill erosion is an intermediate stage between sheet and gully erosion and can be reduced by decreasing the water speed and volume with the help of contour drains and grassed waterways. Removal of these Rills can be made easy by the process of farm machinery.
Gully erosion, on the other hand, causes lesser soil erosion but may contribute to a greater loss of soil leading to collapsing of sidewalls if the rill erosion is not controlled properly on time. These gullies can be defined as channels that are deeper than 30cm which are formed as a result of small water flow.
Streambank erosion can be defined as the type of sheet erosion that leads to the loss of soil from the river banks and causes the degradation of banks along the side of the rivers and stream. This type of erosion occurs when a high speed or current of water washes away the land after heavy rainfall.
Major Causes of Sheet Erosion
A major portion of agricultural land and vegetation gets eroded every year due to this soil erosion process. Sheet flow or sheet erosion has become common now-a-days in most of the coastal and hilly areas. As such it not only causes damage to the land but also hampers the cultivation process. Some of the major causes of erosion are discussed below:
Annual flood has been on top causes of soil erosion every year. The areas that experience heavy rainfall and fall under flood-prone areas are more susceptible to sheet erosion.
The thickness of the raindrops and wind force also plays a major role in sheet erosion. The pressure applied on the ground due to the falling raindrops, causes the thin layers of soil to wash away easily with the rain.
Uneven or loose soils are more prone to erosion. We must make sure that the cultivated lands are not too loose, as it gives rise to rill erosion and gully erosion. The damages caused by sheet and gully erosion are huge leading to sidewall collapsing and agricultural loss.
A large amount of deforestation has also resulted in the loss of soil due to sheet erosion. Since, trees hold a high water holding capacity, cutting down of trees results in loosening of the soil and waterlogging. As such, the layers of the soil can be easily washed away by rain.
Therefore, sheet erosion has been a major problem in India today and has greatly affected the cultivation and agriculture of the country. A huge amount of crop lands are affected every year by the sheet erosion process resulting in loss of vegetation. Hence, this article on sheet erosion has been provided to help them get a clearer concept on sheet erosion meaning and causes.