Transcript the causes of desertification

What are the challenges of living in a hot desert environment?
Work as a team to write down as many challenges you feel
living in the desert would present you with…….
Extreme
temperatures
Unreliable water
supply
Lack of
communication
links
https://www.youtube.com/watch?v=oUS-qV-__EA
What is the impact of these challenges?
Expert
Heads
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•
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Soil erosion & drought
Over grazing
Salinisation
Over cultivation
 You are responsible for
reading and summarising
the information into a
paragraph to share with
your team.
 Ensure you include all the
details and key words
 Form well structured
sentences that make
sense.
 You have 5 minutes to
complete this task.
Soil erosion and drought
Soil erosion
This is a problem which affects many areas. When the soil is
left bare, the wind can pick up speed due to the flat land and
blow away the unprotected soil.
The effects of drought in Africa
• The soil is exposed and vulnerable to erosion as a result of
the removal of vegetation and overgrazing.
• Trees, which provide protection from the wind and rain,
are removed to be used as fuel.
• Nomadic tribes are not wandering as much with their
cattle, which puts pressure on the land where they settle.
• When soil is blown away the land becomes useless for
grazing and crops and causes desertification. This is a
problem in the Sahel region of Africa. This problem is
worsened when restrictions are placed on the movement
of nomadic tribes.
Overgrazing
• In the desert there is not enough vegetation (plants) to
support the cattle that are grazing with the tribes or
commercial cattle ranches (businesses). This means that
the cattle eat every last bit of greenery they can find,
including the root. If the root is eaten the plant will never
grow again and therefore cannot replenish itself. In the
future there will be less and less vegetation for the cattle to
graze on and less fuel for use in fires for the tribes.
• Overgrazing will leave the soil open to erosion.
Over-cultivation
• Cultivation means to work the land-mostly for growing
crops.
• With so little land that is suitable for cultivation (growing
crops) in the desert, areas that are used tend to be overcultivated.
• This leaves the soil leached (drained) of nutrients
(goodness) and unfit to grow further crops in the future.
Salinisation
Salinisation occurs when the water in soils evaporates in high
temperatures, drawing salts from the soil to the surface.
These salts are toxic to many plants and make the land
unusable. This has consequences such as low yields, poor
profits and even starvation. Irrigation of land - when water is
brought to land that is naturally dry - can cause salinisation on
desert margins.
It is not just physical geography which is affected when
humans use desert environments. Culturally, when tourists
and new migrants come in culture may be diluted or new
languages picked up
https://www.youtube.com/watch?v=D1s9KYrNI1g
Soil erosion and drought
Over-cultivation
Overgrazing
Challenges of
the hot desert
Salinisation