Soil Erosion Types and Processes

Soil Erosion

• Soil erosion is the displacement of the upper layer of soil, a form of soil degradation caused by natural agents like water, ice, snow, air, plants, animals, and humans.
• It involves three phenomena: detachment of soil particles, transportation, and deposition.

Types of Soil Erosion

• There are two types of soil erosion: natural or geological soil erosion, and accelerated soil erosion.
• Natural soil erosion occurs steadily over a long time and is a normal soil-forming/soil weathering feature of any landscape.
• Accelerated soil erosion occurs due to disturbance in natural equilibrium by human and animal activities, leading to land mismanagement and destruction of forests.

Phases of Soil Erosion

• Detachment of soil particles
• Transportation of soil particles by wind, water, and gravity
• Deposition of soil particles

Permissible Soil Loss Limit

• The permissible soil loss limit is defined as the maximum rate of soil erosion that will permit a high level of crop productivity.
• The generally accepted permissible soil loss limit is 11.2 t/ha/yr.

Soil Erosion in India

• According to ICAR, more than 120 million hectares of land area in India are under various forms of land degradation, with 74 million hectares affected by water erosion.
• Water erosion alone contributes to 5334 million tonnes of soil loss every year, at a rate of 16.4 t/ha/yr.

Types of Water Erosion

• Splash erosion: the first stage of erosion, where raindrops hit bare soil, breaking up soil aggregates and causing individual soil particles to be splashed onto the soil surface.
• Sheet erosion: uniform removal of soil in thin layers by the forces of raindrops and overland flow.
• Rill erosion: detachment of soil particles by surface flow, resulting in small parallel channels called rills.
• Gully erosion: formation of deep wide channels when channelized runoff is sufficient in volume and velocity.
• Landslides: sliding down of large chunks of soil due to steep slopes.

Wind Erosion

• Wind erosion is a serious problem in areas where land is bare and devoid of vegetation.
• Wind erosion occurs in three stages: saltation, surface creep, and suspension.
• Saltation: the first stage of movement of soil particles in a series of jumps.
• Surface creep: rolling of coarse grains along the surface of the ground by wind.
• Suspension: floating of fine dust particles through the air, carried long distances by wind.

Learn about the different types of soil erosion, including natural and accelerated soil erosion, and the processes involved in soil degradation, such as detachment, transportation, and deposition.