PAPER 1: SECTION B: LIVING WORLD

7. DESERTIFICATION in the SAHEL REGION

Use your exercise book – this is REVISIONMissing work? Ask your teacher or borrow a book.

Tables will need to be made bigger – check before you print.

What is desertification?

Unscramble the word:

When P T I R D O U C V E __________________ land is turned into non-productive land.

Using the map below, describe the distribution ofa) Areas of existing desert

b) Areas at risk of desertification

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Watch this clip:https://www.bbc.com/bitesize/guides/znxsgk7/revision/4

Read the facts in the table and complete the column with the correct cause of desertification. Here are your choices:

Over cultivation (farming) Population growth Climate change Overgrazing

Cause of desertification

Facts about changes How this change has caused desertification

Drier conditions and unreliable rainfall now.On average, it now rains less than it did 50 years ago.

Fill in the gaps using these words:

dies exposed (visible) washedbakes roots wind

Population in the Sahel has gone from 30 million in 1950 to 1000 million now.

More people means:- Lots of trees

cleared to make room for farms and villages

- Lots of trees cut down for firewood and building

More people means more crops need to be grown which uses up the nutrients in the soil. Also, cash crops make money but are often water hungry plants like cotton.People are not allowed to move around now like they used to because of borders so animals stay in one place and eat all the vegetation.

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Strategies used to reduce the risk of desertification

Use a line (or colour) to match each example to the correct description and explanation.

Name of strategy

Examples Description of the strategy

How this strategy reduces desertification

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Stone lines and terraceshttps://www.youtube.com/watch?v=dO16g4LgBjI

Made out of cardboard and reflective material (like foil) and acts like an oven using heat from the sun.

This slows down run-off water down the slopes and allows rich sediment to build up behind it. There is less erosion and more water and nutrients for the crops.

Tree

pla

nting

The Great Green Wallhttps://www.youtube.com/watch?v=bdRDfXFjgZg

Low stone walls are built across slopes.

Uses the sun for energy instead of firewood so less trees are cut down. More trees means roots hold the soil together so less soil erosion happens.

Use

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Solar powered cookinghttps://www.youtube.com/watch?v=uY95ESUYK7Y

Band of vegetation 15 km wide and 7,500km long across 11 countries in the Sahel (Africa).

Leaves – decompose and improve the soil to encourage more growth.Canopy - increases humidity and shade so less watering is needed.Tree roots - holds water in the soil and binds the soil together to reduce soil erosion.

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