Page 227 - New Medley 5 Semester 2

SOIL EROSION

e loss of topsoil by fast blowing wind or owing water is called soil erosion.
Factors Causing Soil Erosion
e main factors that cause soil erosion are wind, water and some human activities.

Soil Erosion by Wind

Strong winds carry away the topsoil very easily. Erosion

due to wind is the greatest in dry areas and where the
land is not covered by plants or has less vegetation.

Erosion by Water

Heavy rain or running water washes away the topsoil
causing soil erosion. Heavy soil erosion occurs in hilly Soil erosion by wind

areas because river water ows faster on the slopes

and takes the fertile soil away. On reaching the plains,

the river slows down and this soil settles down at the

bottom of the river. is is called silting.
e plants hold the soil particles together. Let us

prove it by an activity. Soil erosion by water

• Hands-on Learning
S E
L
Activity Self-Management
To show that plants prevent soil erosion
Take two trays. Place a patch of soil covered with grass
in one tray and fill another tray with soil. Tilt both the

trays by placing a log of wood under one side. Pour
equal amount of water from the upper side of both the
trays. What do you observe?

Water flowing down the soil with rooted plants has very
less or no soil whereas it washes away soil which is without plants.

Soil Erosion due to Human Activities

 To meet the demand of wood, man has been cutting down the trees in forests.
It leads to deforestation which is one of the major causes of soil erosion.

When trees are cut down, soil becomes loose and gets carried away easily.

 Overgrazing by animals in a particular area makes the land dry and barren.
is too results in soil erosion.

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