soil erosion kvg
TRANSCRIPT
3rd semester
-Erosion.
CONTENTS
-Mechanics of erosion.
-Black Sunday
-Types of Erosion
- Agents of Erosion.
-Classification of Erosion.
-Water erosion and its types.
-Factors affecting water Erosion.
-Wind erosion.
- Methods of Soil conservation.
-How to conserve soil ?
The erosion termed indicates the meaning of
soil remove from one place and depositing them
to some another place.
“Removal of soil from its original position”
“It is the process of detachment,
transportation & deposition of soil materials
from one place to another by erosive agents”
Every year in India 16.5 tons/ha/year soil
erosion is occur by agents of erosion.
WHAT IS EROSION ?
Mechanics of erosion
A) Detachment.
B) Transportation.
C) Deposition.
Types of Erosion
In general there are two types of soil erosion.
1. Geological Erosion:-
It is caused by nature.
2. Accelerated Erosion:-
It is caused by human activities.
Agents of Erosion
1. Wind. - ERODIBILITY
2. Water. - EROSIVITY
3. Temperature.
4. Biological Factors.
Classification of Erosion
Depending upon the erosion causing
factors
A) Wind Erosion.
B) Water Erosion.
Types of water erosion:-
1.Rain splash erosion.
2.Sheet erosion.
3.Rill erosion.
4.Gully erosion.
5.Stream bank erosion.
Other forms of erosion:-
1.Glasical erosion.
2.Snow erosion.
3.Organic erosion.
4.Underground Erosion.
5.River erosion.
• 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.
Sometimes water flows as a sheet over
large areas down a slope. In such cases
the top soil is washed away. This is
known as sheet erosion.
Sheet Erosion
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.
• Gullies: The running water cuts
through the clayey soils and
makes deep channels as gullies.
Gully erosion
Stream Erosion.When flow in gullies become permanent,
it is called a stream which may be
permanent or seasonal is called as stream
erosion.
Factors affecting water Erosion
A) Climate.
1. Precipitation.
2. Temperature.
3. Wind.
4. Humidity.
5. Solar radiation.
B) Soil.
1. Physical properties of
soil.
2. Vegetation cover.
3. Organic matter
contents in soil.
4. Moisture contents of
soil.
5. Soil density.
It is the process in which removal of soil
particles moves one place to another place by
wind in known as wind erosion.
Wind erosion
Black Sunday
• April 14th,1935 black
Sunday was the worst
blizzard of the dust storm
with high speeds which
caused the most extensive
damage. It occurs in
United states in Boise city
at 5:15 PM. It is estimated
to have displaced 300
thousand tons of topsoil
from the Prairie area in the
US.
Methods of Soil conservation
• ii. Terrace Farming:
Steps can be cut out on
the slopes making
terraces. Terrace
cultivation restricts
erosion. Western and
central Himalayas have
well developed terrace
farming.
i. Contour Ploughing:
Ploughing along the
contour lines can
decelerate the flow of
water down the slopes. It
used in tea cultivation.
• iii. Strip Farming:
Large fields can be divided
into strips. Strips of grass
are left to grow between
the crops. This breaks up
the force of the wind.
• iv. Shelter Belts: Planting
lines of trees to create
shelter also works in a
similar way. Rows of such
trees are called shelter
belts. These shelter belts
have contributed
significantly to the
stabilization of sand dunes
and in stabilizing the desert
in western India.
Conservation of soil can be done several ways. Planting trees helps. Trees prevent erosion both with their roots and by blocking wind. Terracing is another good way to conserve soil. Terracing is leveled sections used for hilly farm lands. Tilling and plowing helps prepare soil for plants to grow, but it is promotes erosion, so finding ways to limit how much you till and plow will help.
- SOIL AND WATER CONSERVATION ENGINEERING BOOKBY . R.SURESH
- INTERNET