Deserts

• What is a hot desert?


  An area which receives less than 250mm of rainfall per year.
• Where are deserts located?

  Most deserts are located 30 North and South of the equator, between the tropics of Cancer and Capricorn
• Why is the climate so hot and dry?

  Atmospheric circulation means a persistent band of high air pressure remains over the area, creating a lack of rain.
• What is the temperature like at night in hot deserts?

  Cold often below freezing
• What are desert soils like?

  Usually very shallow and a coarse texture as the soil isn't very fertile
• How is the cactus adapted to the hot desert?

  -Spikes to protect themselves from animals -Thick, waxy skin to reduce to reduce transpiration-Can expand to hold more water when it rains-Large root system jut below the surface so when it rains they can absorb as much as possible -seeds stay dormant for years but germinate quickly when it rains
• How is a camel adapted to the desert?

  -Long eyelashes to keep sand out their eyes-Hump which contains fat which can be transferred into energy -Lose little water in urine and are able to drink 46l in one session, this helps with the lack of water in a desert-Padded feet for traveling large distances
• Where is the Thar Desert located?

  The Thar Desert is North West of India and South East to Pakistan. It is 27 North of the Tropic of Cancer
• Thar Desert opportunities-Mineral extract

  The removal of solid minerals such as Feldspar and Kadin which can be used in industry. Limestone and marble are quarried which are used in construction. This helps the Thar Desert socially and economically as it provides trade and jobs benefiting the local community.
• Thar Desert opportunities - Tourism


  The Thar desert National Park and attracts thousand of tourists each year due to it's impressive landscape.Tourism creates a multiplier effect as it means the local community can get jobs as tour guides as well as allow services such as accommodation to be set up.Camel safaris, festival in Jaisalmer.
• Thar desert opportunities - Energy

  Long hours of sunshine provide an opportunity for solar panels. Additionally, the Thar desert has 75 wind turbines to provide electricity to populated areas. These renewable energy source are sustainable and don't contribute to global warming.
• Thar desert opportunities - farming

  Irrigation - Channeling water from rivers and streams have made commercial farming possible in the arid desert conditions. This provides large scale trade bring more job and money into the area
• Thar desert challenges - Extreme temperatures

  Average temperature is 27.3-This makes working outside, especially for farmers very hard-High evaporation rates lead to water shortages affecting human, animals and plants.
• Thar desert challenges - Very low rainfall


  total annual rainfall is very low-This has a social impact as water is not only used for drinking but also cooking, washing for example-It means locals have to travel far to find water-Farming, subsistence and commercial is difficult as crops and livestock need water
• Thar Desert challenges - Inaccessibility

  Extreme temperatures have resulted in a poor road network. High temperatures melt the road and wind blows sand over them.-This makes trade difficult-If someone gets ill than they have to travel miles to get to a hospital
• What is desertification?


  the process by which fertile land becomes desert.
• Desertification causes -Overgrazing

  As population increases, more land is being used for commercial or subsistence farming. This means there is a greater demand for crops and money making the soil exposed to erosion.
• Which areas are at most risk of desertification?

  Areas which are already on the boundaries of a deserts.
• What is over cultivation?

  where the intensive growing of crops exhausts the soil leaving it barren
• Desertification causes - Population growth

  Desert population is increasing putting more pressure on environmental resources such as wood and water.This causes more trees and vegetation to be cut down leaving the soil exposed to the wind and sun.
• What is irrigation?

  Water from underground sources or from rivers can canals can be sprayed onto crops or used to flood fields.
• What is salinisation?

  It is when water containing salt is evaporated from the soil. Due to the hot temperatures the water is evaporated off the surface but the salt remains. Having salt on the soil means crops and plants die.
• Desertification strategies - tree planting

  Planting trees means there are more roots holding the soil together. Additionally it provides shade meaning less nutrients die in the extreme temperatures. They also absorb carbon dioxide mean they aren't contributing to climate change.
• Desertification strategies - tree planting example

  Acacia trees i the Thar Desert.The Grren Wall in Africa-this reduces soil erosion-trees improve the soil, give protection, enable more crops to be grown
• Thar Desert challenges - water supply

  Traditional drinking water for people and animals is stored in ponds.-Water in ponds can become easily affected with disease and dirt however due to the lack of water people drink it.No hospitals if people get ill from the water meaning death is common
• Desertification causes -Removal of wood

  In developing countries, people use wood for cooking. With deserts becoming more populated more wood is needed.However, if there are fewer trees, than there are less roots holding the soil together as well as less shade from the tree making the soil more vulnerable to erosion.
• Desertification causes - Climate change

  As the worlds atmosphere is warming at a quicker rate due to human activities. Desert climates are becoming more extreme as they get hotter and drier.
• Desertification strategies -Magic stones


  Laying stones along the contours of the land, traps rainwater when it falls. These stones slow down run off water and allow it to be absorbed into the ground. This results in less soil erosion and more water for the crops.