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8/3/2019 Soil Erosion 1267447248 Phpapp01

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By: Cathlin Aseron, Rachelle Azcarraga and Pauline

Tomelden


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What is Erosion?

is a gravity driven process that moves solids

(sediment, soil, rock and other particles) in the

natural environment or their source and deposits

them elsewhere.


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Causes of Soil Erosion

WIND (Wind Erosion)

- Erosion caused by the winds of high velocity that more

likely occur in dry areas where soil is loose and

unprotected by vegetation. Because of this high velocity

of the wind, wind abrasion occurs. This is seen in

ventifacts, or rock fragments that have been cut and

polished by the sandblasting action of windblown

sediments. Loose rock particles that are blown away by

the wind can cause deflation. Example of this is the desert

pavement.


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WAVES

- Erosion produced by the waves and currents in the

ocean. Large waves pound the shore with tremendous

force, producing a hydraulic-lifting action that dislodges

large masses of coastal rocks. The blocks fall to the

ocean bottom, where they undergo more erosion along

with other wave-battered rock debris that hasaccumulated there. The sand and rock fragments grind

each other and scour the shore.


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WATER

- Steeper slope causes water to flow faster. When water flows

rapidly, more soil are carried away.

- Slow moving water carries fine particles. Fast moving water

carries stones, and even big rocks. As water flows, big rocks

strike other particles. The particles break into smaller pieces

and are carried away by water. Water eventually slows down

and large particles settle followed by sand. Fine particles are

deposited along the way. This is the way by which floods cause

erosion.


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GRAVITY

- When the rock is loosened by weathering it is

subject to erosion by gravity. Such erosion mayoccur slowly and imperceptibly, as soil creeps

downhill over a period of years; or it may occur

suddenly, as in a dangerous landslide. Down slope

movements of rock and soil caused by gravity are

knows as mass wasting.


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-As it moves material from higher elevations to lower elevations

where other eroding agents such as streams and glaciers can then

pick up the material and move it to even lower elevations.

- Mass-movement processes are always occurring continuously on

all slopes; some mass-movement processes act very slowly;

others occur very suddenly, often

with disastrous results such as

landslides.


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What can we do to prevent this?

Reforestation

is the planting of trees to replace those that were burnt or

cut.

trees reduce the amount of flowing water. Roots of trees

absorb water and hold the soil together. Leaves that fall on

the ground holds the soil.

Growing grass/ Planting Vegetables

grass and vegetables help prevent soil erosion.

Grass: it has thick roots that holds the particles of the soil. If

there is no grass, wind will carry the topsoil away.


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Contour Plowing and Terracing

Contour Plowing is cultivating along curve lines that go around the

hill at a fixed level. Contour Plowing slows down the runoff of soil

water from the land.

Terraces keep water from the hillside. The water is absorbed and

does not follow directly down hill. It also prevent soil from moving

down hill.

Planting trees around farmlands

farmers plant rows of trees(wind breakers) to surround

big areas of farmland. These trees protect the farm

from the wind that causes soil erosion.


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Strip Cropping

is the alternate planting of grasses and crops. It prevents

the top soil from being blown away by the wind or washed

away by rain. Grasses that remain after the crops are

harvested hold the soil together.


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QUESTIONS!


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NUMBER1

Enumerate 3 causes of Soil Erosion and 4

ways that we can prevent Soil Erosion. (Itshould come from the ones that we

discussed)

Gravity, Water, Waves, Wind

Reforestation, Planting

vegetables/growing grass, Contour Plowing

and Terracing, Planting trees around

farmlands, Strip Cropping


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NUMBER2

What is Strip Cropping?

It is the alternate planting of grasses andcrops.


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NUMBAR 3

Why can Contour Plowing help prevent Soil

Erosion?

It absorbs water, and it prevents the

water from going down hill.


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NUMBER4

Define Erosion in your own words.

It is when the solid particles such assediments, rocks and other particles in the

natural environment are deposited

elsewhere.


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NUMBER 5

Enumerate 2 causes of Soil Erosion, andexplain why it is a cause.

Wind: It occurs in dry places where soil is

loose and unprotected by vegetation. Water: Fast moving water can carry small

particles and even rocks, that can strike otherparticles too.

Waves: Large waves can pound the shoremaking it to break more particles.

Gravity: Mass-wasting Down slopemovements of rock and soil caused by gravity.


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NUMBER6

Enumerate 3 ways to prevent Soil Erosion

and explain why it is a way to prevent it. Reforestation, Contour Plowing,

Terracing, Strip Cropping, Planting

vegetables/Growing grass, Planting trees

around farmlands.


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NUMBER 7

Why is it necessary to plant trees around

ones farmland?

It protects the farm from the wind that

causes soil erosion.


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NUMBER 8

What is the difference between the two

causes of Soil Erosion? Waves and Water.

Waves pound shores with tremendous

force directly while, fast moving water carrybig rocks that strike other particles that

break down to smaller particles.


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NUMBER 9

Why is Gravity a cause of Soil Erosion?

Due to the heaviness of the soil, it can

easily be pulled down by gravity.

Change of climate


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NUMBER10

Give 3 ways that a student can do to

prevent Soil Erosion. Not picking flowers or plants, plant plants

in your garden, promote the importance of

preventing soil erosion

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