Water erosion

Muhammad Nadeem Ashraf
Faculty of Agriculture, Rawalakot.

1. WATER EROSION

Muhammad Nadeem Ashraf
Student, Soil & Environmental Science
Faculty of Agriculture, Rawalakot

2. EROSION
“Removal of soil from its original position”
Or
“It is the process of detachment,
transportation & deposition of soil
materials from one place to another by
erusive agents”

3. Some Facts
A) Detachment.
B) Transportation.
C) Deposition.

4. Types of Erosion
In general there are two types of soil erosion.
1. Geological Erosion.
2. Accelerated Erosion.

5. Main causes of soil Erosion
1. Misuse of land.
2. Mismanagement of arable land.
3. Deforestation.
4. Poor soil & water management practices.

6. Agents of Erosion
1. Wind.
2. Water.
3. Temperature.
4. Biological Factors.

7. Classification of Erosion
(Depending upon the erosion causing factors )
A) Wind Erosion.
B) Water Erosion.

8. Water Erosion
“ It is the detachment, transportation & deposition
of soil particles by the force of water from one
place to another.”

Soil erosion by water is the result of rain
detaching & transporting of vulnerable soil,either
directly by means of rain splash or indirectly by
rill & gully erosion.

9. Forms of water erosion
A). Rain Splash Erosion:
Rain splash erosion is caused by the impact of
water striking the surface of soil.
It takes place in two steps.
1. As precipitation fills the pore spaces, loosening
& driving soil particles apart.
2. Impact of subsequent rain drops hitting the
surface, transporting particles to other area.

10. Rain splash erosion caused a dimpled like
appearance.

11. Sever rain splash erosion.

12. B) Sheet Erosion.
“ It is the uniform removal of soil in thin
layers in sloping land resulting from rain
splash erosion.”
surface runoff forms when the rainfall
intensity of a storm exceeds the infiltration
capacity of soil.

13. Sever sheet erosion on a field.

14. C) Rill Erosion.
It is caused by water concentrating into
innumerable, closely spaced small
channels. Left unchecked, rills can cut
vertically & horizontally and when joined
form gullies.

15. Rill erosion on a field.

16. Rill erosion on a field.

17. D) Gully Erosion.
Gullies are steep-sided trenches formed by
the coalescence of many rills.Once they are
started difficult to stop.
Stages of gully erosion.
Stage-1. Cutting top soil.
Stage-2. Enlargement of gullies.
Stage-3. Healing stage.
Stage-4. Stablization.

18. Gully Erosion.

19. Types of Gullies.
1. U-shaped.
2. V-shaped.

20. E) Stream Erosion.
When flow in gullies become permanent, it
is called a stream which may be permanent
or seasonal is called as stream erosion.

21. Stream erosion.

22. Factors affecting water Erosion
A) Climate.
1. Precipitation.
2. Temperature.
3. Wind.
4. Humidity.
5. Solar radiation.

23. B) Soil.
1. Physical properties of soil.
2. Vegetation cover.
3. Organic matter contents in soil.
4. Moisture contents of soil.
5. Soil density

C) Topography.