Detachment and movement of soil material by the action of wind is known as wind erosion. Wind erosion is a common cause of land degradation in the arid and semi arid

1. Wind Erosion
By: Shahab Ud Din, Tariq Abdullah
To: Dr. Ashraf
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2. C o n t e n t s
 D e f i n i t i o n
 E f f e c t s o f w i n d e r o s i o n
 C o n t r i b u t i n g f a c t o r s
 M e c h a n i s m
 T y p e s o f e r o s i o n
 C o n t r o l m e a s u r e s
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3. “
”
Detachment and movement
of soil material by the action
of wind
WIND ERO SIO N
Wind erosion is a common cause of land
degradation in the arid and semi arid
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4. E f f e c t s o f w i n d e r o s i o n
 S o i l f e r t i l i t y
 E x p o s e d e n s e c l a y s u b s o i l s
 S a n d b l a s t i n g
 A i r p o l l u t i o n
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5. Soil fertility
 Soil fertility is reduced because of the loss of the plant nutrients that are
concentrated on fine soil particles and organic matter in the topsoil. This
reduces the soils capacity to support productive pastures and sustain
biodiversity.
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6. Expose dense clay subsoils
 The erosion of light-textured topsoil can expose dense clay subsoils.
 These smooth and bare areas, called claypans or scalds can cover
hundreds or even thousands of hectares.
 They are difficult to revegetate due to the lack of topsoil, low permeability
and their often saline nature.
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7. Sandblasting
 Sand grains transported by strong winds can damage vegetation in their
path by sandblasting.
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8. Air pollution
 Air pollution caused by fine particles in suspension can affect people's
health and cause other problems.
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9. C o n t r i b u t i n g f a c t o r s
 Wind speed & duration
 Soil properties
 Land surface factors
 Overgrazing by livestock
 Periods of drought
 breakdown of the biological soil crust
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10. Wind speed & duration
 Wind speed of which have develop the relationship with the rate of soil
erosion caused by the action of wind
 The wind speed required for erosion depends on the size, weight and
wetness of the soil particles.
 The wind is about 16km/h at a hight of 30cm above the land, required for
significant erosion to occur.
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11. Soil properties
 Wind erosion is inversely proportional to structural stability.
 As structural stability increases, chances of wind erosion decreases.
 As OM increases structural stability increases, thus decrease in wind erosion
 As SOIL MOISTURE increases structural stability increases, thus decrease in
wind erosion
 Among all, sandy texture having lower structural stability.
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12. Land surface factor
 Improves the roughness of land decrease wind erosion
 Presence of vegetative cover decrease wind erosion
 In flat topography, more air flow, so more wind erosion
 In contour topography, less air flow, so low wind erosion
 More tree plantation, results in lower wind speed and hence, low wind
erosion.
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13. Overgrazing by livestock
 Overgrazing by livestock is a prime cause of wind erosion.
 Grazing pressure can also occur from kangaroos and wallabies, as well as
feral animals such as rabbits, goats and camels
 Wind erosion occurs due to loss of vegetative cover.
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14. Periods of drought
 Periods of drought associated with a negative impacts
 provide the highest levels of wind erosion activity
 Dominant in arid to Sami-arid conditions, due to low rainfall
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15. Breakdown of the biological soil crust
 The breakdown of the biological soil crust, which is a characteristic of
many arid zone soils, makes soils susceptible to wind erosion.
 This living crust incorporates algae, lichens, mosses and liverworts and
protects the soil from all forms of soil erosion.
 Crust cover can take many years to recover once damaged
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16. M e c h a n i c s o f w i n d e r o s i o n
 The loss of soil movement involves two processes.
 Detachment
 Transportation
 The lifting and abrasive action of wind results in detachment of tiny soil
grains which apart. When the wind is laden with soil particles, however, its
abrasive action is greatly increased.
 The impact of these rapid moving grains dislodges other particles from soil
aggregates
 The transportation of the particles once they are dislodged take place in
several ways
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17. Abrasion process
The basic mechanics of wind erosion
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18. Types of erosion
 Saltation
 Surface creep
 Suspension
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19. Saltation
 The bouncing or jumping of soil particles by the action of wind is known as
saltation.
 The soil particles having the diameter 0.05mm to 0.5mm are moved as
saltation
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20. Surface creep
 It is rolling or sliding of soil particles along the soil surface by the action of
wind
 Soil particles having diameter 0.5mm to 2mm are detached and moved
by surface creep.
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21. Suspension
 The floating of small particles n the air and there movement by the air.
 Particle size is less than 0.05mm
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23. C o n t r o l m e a s u r e s
 Wind breaks
 Vegetative cover
 Mulching
 Cropping system
 Soil moisture conservation
 Tillage operations
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24. Wind breaks
 Any barrier placed perpendicular to direction of wind will help to reduce
wind speed near ground level and consequently reduces wind erosion
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25. Vegetative cover
 It protect the soil against direct striking by wind.
 So, vegetative cover reduce the wind speed and reduce the wind erosion
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26. Mulching
 Mulching of soil organic or synthetic material i.e. sugar straw and polethine
sheet, reduce wind erosion by protecting against the direct striking the
wind.
 It also conserve moisture.
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27. Cropping system
 It should be such that soil should not be fellow at any time.
 Shallow and deep rooted crops should be cultivated
 Which improves soil structure and reduce the rate of wind erosion.
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28. Soil moisture conservation
 It helps to improves the biological activities in the soil,
 Leading to an improve in soil structure
 Thus may reduce the rate of wind erosion.
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29. Tillage operations
 Tillage operations should be perpendicular to the direction of wind.
 Which helps to reduce wind speed and consequently wind erosion.
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30. Shahab Ud Din
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31. Any Question
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32. Thank you
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