Case Study: Desertification in the Sahel region
What: Desertification Why (Physical Causes):
When: 2004 onwards  Rains are lighter and more
erratic than before- 25 day
Where: Sahel region
Why (Human Causes):
o Poor farming methods
o Land clearance using slash
rainy season has now ceased
and burn.
(specifically Mali and
 3 month wet seasons
o Overgrazing.
Niger)
unpredictable.
o Lack of nutrients in the soil.
Reduction of evapoo Taking too much groundwater
transpiration of plants (due to
(over abstraction)
deforestation) so reduced
o Not allowing land to rest.
water in the water cycle.
oPloughing up and down
 Increase of continental air
slopes.
travelling to region which has
o Deforestation- extinct forest
lack of moisture.
in Niger by 1981.
Perennials - A plant which has a life cycle which lasts more than two years.
Effects:
Social:
Economic:
Environmental:
Political:
GD 2014
Affects over 1 billion worldwide- links to poverty and locals trying to live
off the land to survive. Severe drought in Mali and Niger in 2004 with a
plague of locusts destroying crops. 3.3 million residents (800,00
children) at risk from food shortage. 17,000 malnourished children.
24000 die in Africa each day from hunger.
$42 billion lost to desertification each year.
Residents harvest 1/7 of the land that they used to (lower yields of
crops). Farmers do not allow fields to rest- after harvest the soil is left
bare and is susceptible to wind erosion and leaching. 250,000 hectares
are being lost each year in Niger about the same size as Luxembourg.
The countries most affected by desertification are often, economically,
the least equipped to solve the problems associated with it.
Government provided £500,000 on diet and nutrition. Conflict over land
use and farming techniques- especially with Yacouba Sawadogo.
Desertification is a type of land
degradation in which a relatively
dry land region becomes
increasingly arid, typically losing
its bodies of water as well as
vegetation and wildlife.
Responses:
• The Great Green Wall of
trees- developed by Africa
Union to reduce
desertification.
• Plant perennial plants to
anchor soil creating colloids
(large lumps of soil)
resistant to erosion.
• Bunds- reduced soil
erosion and increase rain
infiltration.
• National Action
Programme (NAP) to
reverse problem.
• UNICEF emergency aid for
14,000 malnourished
children.
• Yacouba Sawadogo Zai
techniques (see Googleplay)
Exam questions:
GD 2014
What does desertification mean?
[1]
Look at the map above.
Describe the location of the Sahel.
[3]
Describe the distribution of other regions at risk of
desertification.
[4]
Describe and explain ways that desertification can be
reverse sustainably. You may wish to use diagrams and
case study examples in your answer.
[6]
Using evidence from Figure 2, compare rainfall patterns
in the Sahel before 1965 with the period 1965 to 1995.
[4]
What is meant by the term ‘drainage basin’?
[1]
Study the diagram.
Name one store and one flow on the diagram.
[2]
Describe TWO routes by which rainfall may enter the
stream.
[2]
Suggest and explain TWO way in which human activity
can change the water cycle.
[4]
Describe and explain ways that water can be conserved
sustainable. You may wish to use diagrams and case
study examples in your answer.
[5]
CASE STUDY: An area that has undergone desertification.
i.
Name and locate an event.
ii. Describe the human and physical causes that has created
the problem of desertification.
iii. Explain the affects to people and the environment. [8]
CASE STUDY: An environment that has been used in an
unsustainable way.
i.
Name and locate an event.
ii. Describe how people or organisations have affected the
environment.
iii. Explain why this is unsustainable.
[8]