Soil Erosion, Types of Soil Erosion i.e. Wind and Water Erosion, Effects and Control Measures of Soil erosion

1. SOIL EROSION
Avin Kharel
IAAS, Lamjung Campus(TU)
4/13/2021
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2. Soil Erosion
 Wearing away of land surface by running water, wind, ice or other
geological agents including such processes as gravitational creep.
 Process of detachment and movement of soil particles or rocks from one
place to another by some agents including human being activities.
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3. Classification of Soil Erosion
Geological Erosion or Normal Erosion
Accelerated Erosion
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4. A. Water Erosion
-Erosion of soil caused by water
-Water acts as erosive agent (detachment & transport sediments)
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5. Process of Soil erosion by Water
Three-step process
• Detachment of particles from the soil mass
• Transportation of sediments (floating, rolling, dragging, splashing)
• Deposition
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6. Types of water erosion
 Raindrop Erosion/Splash Erosion
 Sheet Erosion
 Rill Erosion/ Micro-channel
 Gully Erosion
 Stream channel Erosion
 Landslide/ Slip Erosion
 Ravines
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7. Types of Water Erosion
 Raindrop/ Splash Erosion
-Direct impact of raindrop on bare soil
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8. Types of Water Erosion
 Sheet Erosion
-First stage of erosion
-Removes a thin covering of soil from large areas
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9. Types of Water Erosion
 Rill Erosion
-Second stage of erosion
-Minute finger shaped grooves over entire field
-Occurs if sheet erosion is unchecked
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10. Types of Water Erosion
 Gully Erosion
-Occurs if rill erosion is unchecked
-Wider and deeper channel of tiny grooves
-Cultivation become difficult
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11. Types of Water Erosion
 Ravines
-Deeper and wider gullies
-Formed after prolonged process of gully erosion
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12. Types of Water Erosion
 Landslide/Slip Erosion
-Sliding mass of soil due to steep slope
-Occurs when slope exceeds 20%
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13. Types of Water Erosion
 Stream bank Erosion
-Removal of soil either from stream bank or from channel bed
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15. Factors Affecting Water Erosion
Rainfall
Vegetation
Soil
Man and Beast
Slope of watershed
Topography
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16. Loses due to Water Erosion
Damage to soil
Soil Loss
Depletes water supplies
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17. Control Measures of Water Erosion
Strip cropping
Contour cultivation
Conservation tillage
Mulching
Cropping System
Use of chemicals(Polyvinyl alcohol-aggregate stability)
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Contour cultivation
Strip cropping

18. B. Wind Erosion
 Soil particles on the land surface are lifted and blown off as dust storms.
 Wind velocity, turbulence, shape and size of soil particles, soil structure,
texture, cohesiveness, bulk density and moisture play significant role in
wind erosion
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19. Mechanism of Wind Erosion
 Saltation
 Surface Creep/ Soil Creep
 Suspension
Surface Creep Saltation Suspension
Size Particles 0.5-1 mm 0.1-0.5 mm <0.1 mm
Proportion 5-25% 50-90% 3-38%
Affected Soil Coarse sand Medium sand Clay, silt and
humus, fine
sand
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Mechanism of Wind Erosion

21. Losses due to Wind Erosion
Drifting of dust particles
Damage to crop
Soil Loss
Socio-Economic effect
Air pollution
Removal of silt, clay and organic matter
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22. Control Measures
Reducing wind velocity at ground surface
Increasing size of soil aggregate
Keeping the soil moist
Trapping the saltation particles
Various oil or soil based emulsion
Organic Matter
Tillage
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23. Thank you
AVIN KHAREL
IAAS, LAMJUNG CAMPUS (TU)
EMAIL:aveenkharel005@gmail.com
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