Case Study 9
A case study of an area suffering from desertification: causes, effects, management
Name: The Sahel Region, Northern Africa (countries include Senegal, Burkina Faso, Sudan and Niger). It is a belt that runs
across Northern Africa south of the Sahara Desert. The region is semi-arid with low bushes and shrubs as vegetation.
Inhabitants have a traditional Nomadic lifestyle herding cattle and moving to where there is water / vegetation.
Natural
Causes
Causes: Ultimately desertification happens because of vegetation being lost and soil becoming exposed. Vegetation dies /
is removed for a number of reasons. Once it has gone the soil becomes exposed and is more likely to erode and dry out
further allowing the spread of the desert.
Description
Explanation
Climate change means
temperatures are getting
warmer
Unreliable / below
average rainfall in the
region
Increases evaporation from the soil which dries out and becomes unusable. Less moisture in the
soil means less being evaporated and so less condensation means less rainfall to add moisture
to the soil. Vegetation dies out and soil is exposed.
Less rainfall means vegetation dies out and soil becomes exposed. Rainfall is unreliable and in
some years does not come at all leading to drought (severe water shortage) and as a result
desertification.
Human causes are mainly linked to an increased population in the area which has resulted in poor land use and the farming of land too
much so that it cannot recover. An increase the population caused by reduced death rates has meant a demand for more food and
resources such as water and land.
Description
Explanation
Overfarming – the same
land has been used too often
and the soil cannot recover.
Some land has been farmed
that is unsuitable for farming
and so has been damaged.
When land is not allowed to recover the soil loses structure and nutrients making it more
vulnerable to erosion from wind and any rain that may fall.
The land loses all nutrients from being over farmed and so eventually nothing can grow. This
means desertification is more likely as there is no protection from the weather and land
begins to turn to dust.
Human Causes
Overgrazing - the
destruction of the protective
vegetation cover by having
too many animals grazing
upon it.
Irrigation - the artificial
watering of land and crops.
Usually in areas where the
land is dry. Water is taken by
diverting natural water
courses leaving other areas
short of water and more
prone to drought and
desertification.
Deforestation - the
complete clearance of
forested land.
The growing population of
the Sahel region has led to
increased demand for
firewood and building
materials.
The increased population in the area results in an increased number of cattle being herded
on the same land.
The increase in numbers mean local people move around less so the same land is
repeatedly grazed and all protective vegetation is removed. This leaves it open to erosion
and dust.
The damaged and unprotected land turns to dust and becomes useless for farming crops or
cattle.
Water can also be sourced by pumping it from underground stores. This lowers the level of
the water table meaning that tree roots can no longer reach it and therefore die off.
The lack of tree and vegetation cover in regions with a dry climate leaves areas prone to
erosion and therefore desertification.
The removal of water supplies for other farmers’ herds of cattle means there is more pressure
on other sources and land will be more likely to be over grazed as well.
Trees have been removed in large numbers which decreases the amount of transpiration in
the region. This leads to less rainfall and an increased likelihood of drought and
desertification.
Once all the trees have been cleared there is also a shortage of fuel wood. This results in
locals burning manure instead which means less fertiliser and the degradation of the soil.
This results in less vegetation cover and more erosion over time.
Some areas of forest have also been cleared to make room for crops to be gown but as the
soil has no protection this does not last longs as nutrients are used and soil is exposed.
Summary to show the different causes of desertification and how they
link to a decline / loss of vegetation.
Effects: Desertification affects bot the natural environment and the population that is living there.
Effect
So what?
Soil erosion becomes a key process so…
The hot sun leaves exposed soil baked and cracked
so…
Plant and animals species die out so…
Dry soil and sand means an increase ins and storms
so…
Local population cannot find enough water or food for
cattle so…
Local population have no food or water so…
Without food or water many people migrate to cities
so…
If an entire country is suffering from drought and
desertification people may be forced to leave so…
…soil is washed away and no crops or vegetation can
grow.
…any rains that fall cannot infiltrate and may cause
flash floods.
…there is a loss of biodiversity (less variety of plants
and animals).
…any surviving vegetation and crops are smothered
and die.
…crops and cattle die leaving less food for the
population.
…may struggle to survive and lead to famine, causing
death on a large scale.
…informal settlements and shanty towns become more
crowded and overpopulated.
…they will have to take refuge in another country and
become a refugee reliant on aid.
Environmental?
Human? Both?
Both
Both
Environmental
Both
Human
Human
Human
Human
Management / Solutions:
Strategy
Magic
Stones
Description
Why it works / benefits
Building piles of stones that
are placed across the slope
which stops surface water
from quickly running away
and eroding the soil. The
collected water has time to
sink into the dry soil.
Better Wood
Burning
Stoves
Supplying families with clay
stoves that are efficient and use
less wood for each cook.
Reduces the amount of smoke
inhaled by the user as well.
Eg Upesi stove in Kenya
Rainwater
Harvesting
Collecting rainwater during the
wet season so that it can be
used through the dry periods.
Use trenches and metal roofs to
collect water
- Run-off is slowed by the stones and gives more time for infiltration.
- Allows soil moisture to recharge and makes the soil better able to grow
crops.
- Stones also trap any soil that has been eroded meaning there is better
crop growing potential.
- Cheap to build as they only need manpower and stones that are already
there.
- Effective on a small scale as they have shown to increase the amount
grown on the land by 50%.
- Reduces the demand for wood as less needed each time
- Less deforestation for fuel and an improvement in the health of the
women in rural villages.
- Stoves use clay from local riverbeds and so are cheap and easy to
make – they cost the same as a chicken.
- Communities are also encouraged to take fuel wood only from branches
of trees rather than chopping the tree down so that there is still some
protection.
- Do not have an impact on the surrounding water levels and are cheap
and easy to maintain they are usually sustainable.
- Allows crops to survive dry periods as there is a supply of water for
irrigation.
Planting
trees
Returning land to vegetation
through replanting of trees.
Projects have been funded by
international money to stop the
spread of desertification
- Trees protect the soil from wind and rain and the tree roots help to bind
soil and prevent erosion.
- Trees improve the nutrients in the soil so other crops can grow
- Shade also allows other crops to grow providing food for local communities
- Tree leaves provide shade and intercept rain water meaning more will
infiltrate the soil.
- They are a cheap and long term solution to the problem.
- If managed carefully the trees could be a source of fuel wood and
building material in the future.
Examples
The Acacia Project, Senegal
The Great Green Wall, The
Sahel
Changing
Farming
Methods
Crops:
- Use a wider variety of crops
- Use higher yield varieties (so
you get more from 1 plant).
- Use drought resistant crops
which survive the dry conditions
Grazing Animals:
- Reduce the numbers grazing
the land
- Enclose the herds so only
small areas used
Combined:
- Encouraged to grow crops and
herd cattle in same areas
Internationally funded project to plant Acacia Gum trees in dry areas of Senegel
Locals provided with seeds, tools (eg tractors) and training to plant the trees
- Project has:
- Prevented soil erosion / spread of desertification
- Provides nutrients in the soil for other vegetation / crops to grow
- Removes CO2 from the atmosphere, benefitting climate change
- Provides food for cattle
- Trees can be harvested for Gum Acacia which can be sold and the
money invested in community development eg millet mill / schools
- Made it easier for locals to feed their families
- It is a strip of trees and bushes that is 15km wide by 8000km long across the
north of Africa just south of the Sahara desert.
- It aims to limit desertification.
- Funding has come from international organisations and governments.
- The advantages include: stopping desertification and soil erosion, providing
water and creating habitats.
- Also provides an energy source and food to support the local economic
development.
- Variety helps to bind the soil together and prevents erosion.
- Also helps to return nutrients to the soil.
- Better supplies of food through periods of drought so people less likely
to suffer from drought.
- Soil can regenerate and recover if managed carefully.
- Land not over grazed so can recover and maintain herds for a longer
period
- Smaller area of land affected and so less land at risk of desertification.
- Manure from cattle can improve soil nutrients and make growing crops
more successful.
Global Perspectives: The global community has to respond and react to issues linked to desertification and drought. This
can be emergency aid and longer term development projects
Example: Mali and Niger drought, 2005:
2004 saw these countries hit by severe drought and a plague of locusts. This meant the crops / harvest failed and led to
severe food shortages and famine in 2005. This left 3.3 million people (800,000 children) at risk from a serious food shortage.
Emergency Aid:
- UNICEF spent an extra US$ 270,000 to treat 14,000 malnourished children for six months.
- UNICEF needed over US$1 million of further funds to feed malnourished children with therapeutic food – a
peanut-butter-based food.
- UNICEF also needed the extra funds to purchase 641 tonnes of cereal to restock 65 cereal banks.
Long Term Development Aid:
- Oxfam and other NGOs (charities not linked to governments) support projects to increase
education for the nomadic farmers, especially the girls. Because:
- these are the poorest members of society
- they have been discriminated against
- more boys than girls attend primary school
- women and girls have less status.
- Governments invest money in Sahel countries to improve the diet and nutrition of the
populations.
- 245 cereal banks were opened in UNICEF’s intervention zones to make staple grains (millet and
sorghum) available. Before harvest, when food supplies are low and hunger increases, cereal
banks loan food to mothers. After harvest, the women repay their loans in cash or grain.
- UNICEF supports 300 women’s groups that promote exclusive breastfeeding and monitor
children’s growth in the villages. Women with malnourished children receive loans of goats to
enrich their families’ diets with milk and cheese.
- Twice a year, vitamin A supplements are provided to all children under the age of five years.
- Supplementary feeding centres receive therapeutic food for severely malnourished children.
The aim of UNICEF’s emergency aid was to prevent the starvation and death of children because of the food
shortage. The aim of UNICEF’s development aid is focused on improving nutrition for children and mothers over
the long term so that their general health is gradually improved.