sahel desert case study - desertification

What are the current impacts of desertification on ecosystems?

* loss of nutrients due to overexploitation leaving soils undernourished = biodiversity is reduced
* loss of topsoil, most nutritious layer due to increasing exposure to wind and rain
* salinity on top of soil sue to overuse of irrigation
* depleating water sources meaning plants and animals die
* vegetation dies so animals have to migrate to areas to support life.
* reduced carbon sequestration creating climate change.

what type of feedback loop is the process of desertification and biodiversity in deserts?

* positive

desertification means there is less carbon sequestration in plants

this results in climate change

this increases storm events and droughts

this creates soil erosion causing loss of nutrients

this causes biodiversity loss

decreased plant and soil organisms

what are the current impacts of desertification on humans?

* lack of water - hygiene issues and spread of disease = dependance on aid programs
* loss of vegetation decreases food productivity = abandoning settlements and migrating
* dust clouds = effect air quality and cause respiratory issues
* food insecurity and starvation (disease and high death rates)
* depleted grasslands = people cannot sustain farmlands

where is the Sahel located?

• belt of land with a semi-arid climate, south of the Sahara desert

• across Africa from the atlantic ocean to the Arabian sea

• runs through countries such as chad, nigeria and Senegal

What is the background to the Sahel region?

* depend on natural resources for economic and social needs greatly (landlocked)
* 2/3 of people live rurally = rely on agriculture
* resources of the region are decreasing rapidly
* air and water pollution, deforestation, loss of soil, and decline in biodiversity prevelant
* poverty throughout

why is the sahel region vulnerable to desertification?

• long spans of time with little-no rain (average 8 months of the year are dry)

• climate change worsening droughts

• soil is overused and infertile due to overgrazing and use of agriculture - no crop rotation or time for the nutrients to recover

• extreme poverty humanitarian crisis

how has population increased desertification in the Sahel desert?

* estimated population of 260 million in the region
* this is estimated to double every 20 years. increasing population is faster and greater than the increase in food production putting more pressure on the land.
* increasing population also means more water is needed.

how is the fuelwood crisis effecting the sahel desert?

* most people rely on wood for cooking
* people rarely eat uncooked food and often food that has been cooked for long periods.
* this means land has been stripped of trees with some species going extinct
* not sustainable

how are overgrazing and overcultivation adding to desertification?

* number of livestock grows with the size of the population
* this as lead to overgrazing and reduction on soils protective cover of vegetation.
* animals resort to eating roots to plants will not recover = exposing soil to erosion
* increasing population = more land for agriculture - slash and burn to clear natural vegetation
* over irrigation can lead to salinisation of the soil due to high evaporation rates

what are the ongoing problems in the sahel region?

* civil wars in south sudan
* prevent aid reaching the area and causing mass migration to refugee camps.
* population growth exceeding food supplies

why can there be issues in the sahel region with combating desertification?

* political instability
* poverty
* cycle of poverty is hard to get out of

what are the 4 critical issues about the Sahel regions hunger?

* decades of underinvestment in rural areas
* wars and political conflicts, leads to refugees and instability
* HIV/Aids depriving families
* unchecked population growth

what are the coping methods for desertification in the Sahel region?

* sustainable farming methods
* using more fuel efficient wood stoves
* stone bunds
* ‘green wall’

how are locals using sustainable farming to help desertification?

• drought resistant high yeilding crops can be used. 1973 countries in sahel region to form an alliance to combat drought CILSS in solutions

• farmers plant trees to help bind the soil together and reduce erosion of fertile topsoil

• drought resistant trees are used

• they also create terraces on hills meaning water does not run off onto slopes keeping soil fertile

how are people in the Sahel combatting the problem of a shortage of firewood?

* using more wood efficient wood stoves that are both affordable and easy to use
* this reduces trips that nee to be made to collect wood and allowing tree growth
* also using less wood creates less smoke reducing the effects on people lungs

how are stone bunds used to help with desertification?

* low lying, pile-like, walls that form a barrier to slow down runoff allowing water to seep into the soil
* this helps with building a layer of soil and manure particles, rich in nutrients

what is the great green wall project?

african led project to grow trees across the width of the region. when finished this will be the largest living structure in the world. it started in 2007 annd hhas provided many jobs such as flood security and planting jobs.

what tree is being used to construct the great green wall?

acacia trees

how many countries will the great green wall span across?

11

how wide is the great green wall

15km

what have the efforts in senegal been to the great green wall

* have planted 11 million trees
* locals state that they can be changes to soil health
* previously dry wells have replenished
* has created a new economy

what are the benefits of the great green wall?

* soil moisture, nutrients and overall health
* increased humidity of areas
* leaves provide compost
* offers shade so less need for watering
* tree roots hold water inn the soil
* jobs for men and women

how much is the great green wall project predicted to cost in total?

$8 billion

what are some of the potential problems with the great green wall?

* many trees have been planted in areas with nobody to be able to maintain them
* in the early days of the project nearly 80% of trees dies in two months of them being planted
* insufficient funds mean the project it behind schedule for its 2030 deadline.
* political instability in some regions may mean efforts are inconsistent across the project and unable to be maintained

who initiated the great green wall project?

the African union

What is the population density like in the sahel region?

* population density overall is low ranging from 85 - less than 7 people per square kilometer
* only a small proportion of the land is suitable for agriculture.
* highest population densities relative to cultivable land are 633 people per square kilometer