Hot Deserts

• Hot deserts are mainly found along the tropics
• Hot deserts


  • Sahel
  • Atacama
  • Gobi
  • Great Western
• Typical annual rainfall in hot deserts

  100-200 mm
• Challenges in hot deserts

  • Inaccessibility
  • Extreme temperatures
  • Water supply
• Adaptations of hot desert plants

  • Very long tap roots
  • Water storage in stem
  • Rapid life cycles
• Arid environments may have no rain for decades, have very little vegetation
• Semi-arid environments have a short reliable rainy season, seasonal grassland vegetation, and risk of desertification
• The highest average temperature in any month in a hot desert is 33°C
• The highest total precipitation in any month in a hot desert is 16 mm
• Diurnal temperature range


  The large difference between day and night temperatures in hot deserts due to lack of clouds
• Mineral extraction


  An economic activity in hot deserts
• Energy


  An economic activity in hot deserts, including both non-renewable (oil, coal) and renewable (solar, wind) sources
• Farming


  An economic activity in hot deserts, mainly subsistence and small-scale
• Tourism


  An economic activity in hot deserts, including desert festivals, camel safaris, and providing food/accommodation
• The Thar Desert is located along the India-Pakistan border, has sandy hills, mobile sand dunes, and sparse vegetation
• The Thar Desert has economic opportunities in mineral extraction, energy, agriculture, and tourism, but also challenges like climate, water shortages, and accessibility
• Xerophytic adaptations of desert plants

  • Spikes rather than leaves
  • Large fleshy stems
  • Thick waxy skin
  • Extensive root system
  • White upper surface
• Ephemeral adaptations of desert plants

  • Seeds may lie dormant for years
  • Plants grow quickly after rain
  • Flowers within a few days
• Desertification


  Process of semi-arid grasslands becoming degraded and drier, turning into desert
• Deforestation


  Cutting down or stripping trees, leading to soil erosion and reduced soil fertility
• Overgrazing


  Allowing livestock to graze on an area for too long, stripping vegetation and leading to soil erosion
• Overcultivation


  Intensive use of land to produce more food, exhausting the soil of nutrients
• Soil erosion


  Top layer of soil being blown or washed away due to lack of vegetation cover
• The Great Green Wall of Africa is a project across 11 countries in Northern Africa, started in 2010, to reduce desertification by planting a 15km wide strip of trees and shrubs