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
Wat
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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
of a
ppro
pria
te
tech
nolo
gy
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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