in this we will discus about that how soil erosion occurs..? what are the causes that cause the soil erosion..?? what are the agents of soil erosion..? what are the prevention that helps to prevent the soil erosion ..? what are the principles to conserve the soil erosion.... hope this will help you guys alot...

1. By
Ayesha Azam

2. i. What is soil erosion.?
ii. How it occurs..?
iii. Causes of soil erosion
iv. Agents of soil erosion
v. Erosion by water
vi. Prevention
vii. Conservation principles

3. WHAT IS SOIL EROSION
• Soil erosion is the displacement of the upper layer of
soil; it is a form of soil degradation.
• Soil erosion is a natural process, it becomes a
problem when human activity causes it to occur
much faster than under natural conditions

4. CONT.…
• When a rain drop hits soil that is not protected by a cover of
vegetation and where there are no roots to bind the soil, it has the
impact of bullet
• Soil particles are loosened, washed down the slope of the land and
either end up in the valley or are washed away out to sea by streams
and rivers
• Erosion removes the topsoil of the land first, once this nutrient rich
layer is gone, few plants will grow in the soil again
• Without soil and plants land becomes desert like and unable to
support life..

5. WHEN SOIL EROSION OCCUR..?
• Soil erosion occurs when upper layers of soil are removed from their original
location in the process that is either slow and goes unnoticed for long periods of time
or can be sudden and cause immediate damage
• For example
• Appearance of a rill in the middle of a crop field after heavy rain

6. EXAMPLE OF RILL EROSION

7. CAUSES OF SOIL EROSION
• Overgrazing
• Absence of natural vegetation
• Very less clay content in the soil
• Steep slopes of the land

8. AGENTS OF SOIL EROSION
• Followings are the agents of soil erosion
• Wind
• Saltation
• Suspension
• Surface creep
• Water
• Sheet erosion
• Rill erosion
• Gully erosion
• Slip erosion
• Stream bank erosion

9. SHEET EROSION
Sheet erosion is the movement of soil from rain drop splash and runoff water
It typically occurs evenly over a uniform slope and goes unnoticed until most of the
productive topsoil has been lost
Deposition of the eroded soil occurs at the bottom of the slope or in low areas.

10. RILL EROSION
• The sheet erosion is carried out by very small definable channels
called interrills
• Raindrops detach every layer of soil particles through splash and
detached particles are than carried through interrills by a thin layer
of overland lateral flow
• When the process of soil erosion and deposition through interrills is
prolonged the interrills are widened leading to formation of small
channels called rills

12. GULLY EROSION
• Rills are usually smaller in size and depth. They can be
destroyed by tillage operation.
• Whereashen the rainfall is very heavy, deeper cavities or
gullies are formed, which may be U or V shaped.
• The accumulation of water in narrow cuts (rills) which
removes the soil to considerable depth, these cuts can be
several feet deep.

15. SLIP EROSION
• This occurs due to heavy rainfall on slopes of hills and mountains.
• Slip erosion is also know as landslide.
• When earthquakes occur on areas with steep slopes, many times the soil slips
causing landslides.

16. SLIP EROSION

17. STREAM BANK EROSION
• During the rainy season, when
fast running streams take a
turn in some other direction,
they cut the soil and make caves
in the bank.
• Stream bank erosion is common
along rivers, streams and drains
where banks have been eroded,
sloughed or undercut.

18. STREAM BANK EROSION

19. HOW TO CONTROL SOIL EROSION..??
1- Permanent Vegetation 6- Conserve wetlands
2- No tillage and gardening 7- Grow plants with rich humus
3- Cover Crops 8- Avoid overgrazing
4- Spil erosion control banking 9- use contour ploughing
5- Reduce water runoff 10- Afforestation

20. PRINCIPLES OF SOIL CONSERVATION
• Protection of soil from impact of rain drops
• To slow down the water from concentrating and moving down the
slope in a narrow path,
• To slow down the water movement when it flows along the slope,
• To encourage more water to enter into the soil
• To increase the size of soil particles,

21. CONT.
• Reduction in the wind velocity near the ground by growing vegetation cover, ridging
the land etc. and
• To grow the strips of stubble or other vegetation cover which might catch and hold
the moving particles of soil.

22. IMPORTANCE OF PLANTS IN CONTROLLING
SOIL EROSION
Plants provide protective cover on the land and prevent and prevent soil erosion
• Plants slows dpwn water as it flows over the land and this allows much of the rain
to soak into the ground
• Plants roots hold the soil in position and prevent it from being washed away
• Plants break the impact of a raindrop before it hits the soil thus, reducing its ability
to erode
• Plants in wetland and on the banks of rivers are of particular importance as they
slows down the flow of the water and their roots bind the soil thus, preventing
erosion

23. EFFECTS OF SOIL EROSION
• Soil erosion can deplete the fertility of the soil thereby making the soil unsuitable for
the growing of crops and vegetables.
• Soil erosion can lead to siltation. Siltation is the process whereby a water body gets
polluted as a result of the natural or artificial dumping of things such as mineral
particles, sand, mud, soil, etc into it.
• Loss of top soil
• Soil erosion can uproot certain types of plants – especially shallow-rooted plants. This
happens as a result of the process of the soil erosion eating away at the soil around
the plants or crops. If the plants do not have deep roots, then the process of soil
erosion can cause them to get uprooted whenever the weather becomes windy.

24. CONT.
• Soil erosion can cause significant alteration to the natural shape of
the land. For example, it can make huge valleys to occur on plain
lands.
• Long term erosion
• Soil erosion can also negatively affect the income of farmers. This
happens as a result of the soil losing its fertility and leading to poor
yields. When this happens, farmers’ income reduce drastically because
the soil can no longer properly support the growth of plants.
• Soil acidity level increase