deserts

• Fennec foxes have large ears that dissipate heat and allow them to hear prey underground.
• what is the maximum rainfall in the desert?

  250mm
• dessert soils are thin sandy rocky soils that are very dry and have low nutrient content
• sagaro cactus are adapted to the dessert by having a thick waxy cuticle to reduce water loss
• sagaro cactus are adapted to the dessert by having pleated steam that expands to hold more water
• sagaro cactus are adapted to the dessert by having thorns instead of leaves (less surface area) to reduce water loss
• sagaro cactus can hold how much water?

  1000L
• velvichia plants are adapted to the dessert by having cracks in the leaves to absorb water more effectively
• velvichia plants are adapted to the dessert by having roots on the surface so it can absorb water before it evaporates
• velvichia plants are adapted to the dessert by having very long leaves therefor haveing a large surface area to catch dew from the fog the water then drips onto the soil and the shallow roots absorb the water
• desert holly is adapted to the dessert by having white salt covering the leaves so they reflect the sunlight of them
• desert holly is adapted to the dessert by having salt secreted from the soil and then the salt covers the leaves
• desert holly is adapted to the dessert by having the leaves face away from the sun durning the day so the water in the leaves don't evaporate
• Desertification

  The spread of desert conditions in arid regions due to human activities, drought or climate change
• Main causes of desertification

  • Population growth
  • Removal of wood
  • Overgrazing
  • Soil erosion
  • Climate change
• Population growth

  • Increasing population in some desert areas due to developments in mining and tourism, putting greater pressure on the environment for resources such as wood and water
• Removal of wood- cause of desertification

  • In developing countries, people use wood for cooking. As the population in desert areas increases, there is a greater need for fuel wood. When the land is cleared of trees, the roots of the trees no longer hold the soil together so it is more vulnerable to soil erosion
• Overgrazing- cause of desertification

  • An increasing population results in larger desert areas being farmed. Sheep, cattle and goats are overgrazing the vegetation, leaving the soil exposed to erosion
• Climate change- cause of desertification

  • The global climate is getting warmer. In desert regions conditions are not only getting warmer but drier too. On average there is less rain now in desert regions than there was 50 years ago
• Strategies to reduce desertification

  • Planting more trees
  • Improving the quality of the soil
  • Water management
• Planting more trees- strategies to reduce desertification

  The roots of trees hold the soil together and help to reduce soil erosion from wind and rain
• Improving the quality of the soil- strategies to reduce desertification

  Encouraging people to reduce the number of grazing animals and grow crops instead. The animal manure can be used to fertilise the crops grown. This type of farming is more sustainable
• Water management- strategies to reduce desertification

  Water can be stored in earth dams in the wet season and used to irrigate crops during the dry season. This is an example of using appropriate technology to manage water supplies in the desert environment
• Hot deserts provide opportunities for development but also cause challenges such as desertification
• sonaran desert (case study)

  • Located in south western arizona
  • Has the highest population density close to the desert
• Subsistence farmers

  People who only grow enough food to feed themselves and their family
• Development opportunities in the sonaran Desert

  • Mining
  • Energy generation
  • Farming
  • Tourism
• Multiplier effect

  A positive change in one area has a knock-on effect on other businesses
• Challenges of development in the sonorean Desert

  • Extreme temperatures
  • Water supply
  • Inaccessibility
• mining - - development opportunities

  • gold mines lots of job opportunities for locals
  • gold, silver , quartz and copper are mined here
  • 2.25m of gold extracted from gold road mine
• Energy - development opportunities

  • hoover dam (hydroelectric power) produced in Colorado river provides energy for 3 million people
  • sonaron solar project where 3 acres of desert is cleared and covered in solar panels which provides energy to 91,000 homes
  • both of these create job opportunities for locals
• farming - development opportunities

  • Arizona highest quality cotten due to little rinfall $500million per year
  • grain , wheat , melons , leafy greens all grown in desert
  • 70% of Arizonas water usage is for agriculture
  • takes 5283 gallons of water
• tourism - development opportunities

  las vegas - attracts people for gambling resturants and shops like the bellagio hotel and the strip

  grand canyon - attracts tourrrist which brings money into the economy (the sky walk)
• what city is the bellagio hotel found?

  lad vegas
• what is found in-front of the ballagio hotel that attracts tourist?

  Fountains
• what opportunities does the bellagio hotel bring to las Vegas?

  Tourism, employment, manergers , cooks , cleaners
• what about the grand canyon attracts people?

  the famous $sky walk$ which is a oval bridge that sticks out over the grand canyon with glass flooring to see how far down it goes
• what rule does the grand canyon?

  only 400 people allowed up at the canyon at a time to make sure it safe and everybody can enjoy it
• what is the strip in las vegas?

  a road of the city's best sights, gambling, restaurant's and shops.
• water - challenge of developing in sonoran desert

  • hoover dams water is being depleted by evaporation - evaporation levels are higher then ever before
  • water patrols to catch any leaks or people using it unsustainably like watering there grass
  • people are taking water out and not documenting it