Fringe of hot deserts

• Desertification

  • Where the land, which was once fertile, becomes infertile/ unproductive
  • Drylands/ desert-fringe are areas usually on boarders of hot deserts. They are semi-arid
• Causes of desertification

  • Cimate change:
  • Increases temperature, decreases rainfall adn unstable weather conditions
  • Over-cultivation - repeated growing of crops:
  • Removes nuritents, the soil will become exhausted. Made worse by large-scale machinery
  • Over-garzing - Too many livestock in one area
  • Livestock eats too much vegetation - it can't grow back fast enough
  • Deforestation - Large scale removed of trees/vegetation
  • As vegetation is cut down, interception is reduced. Trees can't grow back enough
• Cycle of desertification

  • The amount of (natural) vegetation decreases (Most important)
  • Less plants means less interception and the soil is exposed to the hot sun
  • The sun bakes the soil dry and it cracks
  • Rainwater runs over the surface (increase surface runoff) then infiltrates down in the soil, wind can attack the soil
  • Soil is washed away or blown away by the wind - eroded
  • The soil is degraded and loses fertility and structures nutrients are removed
  • Soil is worn out/poor quality and its is harder to grow crops
• Reducing deforestation - Approriate technology

  • Solar stoves:
  • Solar stoves are appropriate technology which reduced the use of fuel wood for cooking
  • It sops people foraging fire wood, doesn't generate smoke, helps with respority diseases
  • Reduces deforestation
  • Magic stones/stone lines:
  • Poeple has built low stone walls along the contours of slopes
  • When rain water washes down the hill side, the walls trap water and soil
  • Cheap to build
  • The great green wall
  • A planned project to plant trees across Africa
  • Across 11 countries to prvent the desert spreading south
  • Stops the desert spreading south
• Reducind deforestation - Water and soil management

  • Drip Irrigation:
  • Saves water and fertiliser by allowing water to drip sowly directly onlt the root zone of the plants
  • Water is not wasted on the land between the plants
  • It is cheaper and more efficient than traditional methods
  • Reduces water waste as too much water can lead to high amounts of evaporation which can cause salinisation
  • Afforestation
  • Planting trees, provide fuel wood and building materials for the local people
  • Leaves allow for shade for animals as well as intercept water
  • Cheap, longterm solution
  • Holds the soil together duw to the roots, reduces soil erosion
  • Prevent wind-erosion