Extreme Environments What are hot deserts like? Physical features Barchan Dunes Hot Deserts Cross section There are lots of different types of Sand Dune. They will differ according to the strength/direction of the wind, amount of vegetation, amount and type of sand. As the sand is loose, many types of sand dunes will migrate (move), due to the wind. Sand dunes mostly form when there is an obstacle – the sand builds around the obstacle – e.g. vegetation Prevailing Wind Sand deposited 38

Extreme Environments What are hot deserts like? Physical features Barchan Dunes Hot Deserts A Barchan Dune has a particular shape. It is a crescent shape with ‘horns’ pointing downwind. The upwind slope is approx 34 0 & the downwind slope is approx Barchan dunes occur where there’s a limited supply of sand, therefore they may by up to 100m apart. They form around an obstruction. The obstruction causes the wind to lose speed & then deposits, which causes a greater obstruction & more material is deposited. They will move over time 39

Extreme Environments How do people use hot deserts? Oil and Gas Hot Deserts General  Beneath the Sahara are layers of sedimentary rock. Oil and gas is trapped beneath after is was formed from the remains of microscopic organisms millions of years ago. Positives  Exporting oil and gas can make a lot of money for countries. Negatives  The money isn’t distributed equally in the country & companies are often owned by overseas companies. Oilfield drilling rig It is very expensive to find oil and gas. Many of the larger, easy to find oil wells have now been used up. Transport oil and gas through pipelines is very expensive. Oil & gas are non-renewable resources – one day they’ll run out & burning these releases CO 2. 40

Tourism Many people find deserts to be fascinating and like the idea of visiting a desert. There are many tour companies that offer desert holidays, catering for different experiences – e.g. self drive, buggies, Bedouin tents/camel treks. Extreme Environments How do people use hot deserts? Tourism intro Hot Deserts Positives People are able to find out about different cultures. Some money from tourism will go to locals. Negatives Some areas may have delicate environments which could be damaged by tourism. Some tours companies are foreign owned, meaning that not all money goes to the locals. 41

Extreme Environments How do people use hot deserts? Tourism examples Hot Deserts 41

Extreme Environments How do people use hot deserts? Tourism examples Hot Deserts 41 You need to know:  examples of different activities.  The scale of each activity  The impact upon the environments (+ or -)  The impact upon different groups of people (+ or -)

Extreme Environments How do people use hot deserts? Agriculture Hot Deserts In deserts, there is lots of flat, cheap land which makes it ideal for agriculture. Of course, water is needed for crops to grow. This can either come from irrigation channels which take water from rivers, or from well which takes water from under- ground aquifers (water holding rocks). Positives – allows greater areas of desert to be used. Creates employment e.g Egyptian potato farming Negatives – River levels affects, aquifers will run out of water. Lots of chemicals are needed to feed the plants, as desert sand/soil has v few nutrients. Desert Agriculture Irrigation channel Water pumped up from aquifer 42

The Bedouin The Bedouin are pastoral (raise animals) nomads (they move around from place to place). They overcome problems in the following ways: Water – They plan routes from water source to another. Also, use other indicators such as lines of plants and insects to find hidden underground water. Transport – Bedouins traditionally use camels as transport as they are able to carry large loads. Extreme Environments How do people use Hot Deserts? Hot Deserts Lighting a fire Clothing - They traditionally wear woollen, loose fitting clothes, from their animals. These insulate against the heat of the day & provide warmth at night. Covering their bodies means that the amount of sweating is reduced, therefore reducing dehydration. Shelter–They need to be able to carry their shelter with them & pack up quickly. Their tents are made from Goat hair cloth as it is warm & waterproof. They are long/narrow allowing breeze to blow 43

Extreme Environments How do people use Hot Deserts? Hot Deserts 43 The Bedouin are mostly located in the Arabian Peninsula. The largest group is in Saudi Arabia. There culture is under threat due to:  Country boundaries. Many countries such as Israel and Jordan have strict border controls which stop the Bedouin from travelling  Climate Change. A number of ‘dry years’ have meant that grazing lands have become barren  Political systems. Some countries do not recognise the Bedouin unless they are permanent residents  Toursim. Some bedouin routes have been developed for tourists.  Clash of cultures

Extreme Environments How do people use Hot Deserts? Hot Deserts 43 Their culture is under threat due to:  Country boundaries. Many countries such as Israel & Jordan have strict border controls which stop the Bedouin from travelling  Climate Change. A number of ‘dry years’ have meant that grazing lands have become barren  Political systems. Some countries do not recognise the Bedouin unless they are permanent residents  Tourism. Some Bedouin routes have been developed for tourists – creating a conflict  Clash of cultures. Increased global communication have meant that many Bedouin have chosen to live in cities meaning that traditions are not passed through the generations

Desertification This is the process by which land turns into desert. After a ‘dry period’ land will often recover. Desertification is when the land is so damaged that it can’t recover. The damage can be caused by physical (Natural) processes, or by Human (due to people) processes One of the areas at risk of desertification is the Sahel, in Africa. It is on the southern edge of the Sahara. It is an area where some farming occurs & is mainly grassland Extreme Environments What Challenges do hot deserts pose? Desertification 1 Hot Deserts 44

Desertification - Physical Causes:  Less Rainfall – Overall, there has been a reduction in the amount of rain for the Sahel over the last few years  Less Reliable Rainfall – Also, the rain is less reliable – it may be many years before its rains properly in an area  Higher Temps–This increases the amount of moisture/water lots through evaporation & transpiration (water from plants) Desertification - Human Causes:  Irrigation–water for growing crops is quickly evaporated, salt in the water is left on the ground=unsuitable for future farming  Over grazing – Herds of animals eat lots of vegetation. Too many animals means that the vegetation cannot recover  Over farming – Soil can’t recover from lots of farming. It loses it nutrients and loss of vegetation means that it blows away.  More people - Many people in the Sahel use firewood. More people means too much may be collected-plants cannot recover. Extreme Environments What Challenges do hot deserts pose? Desertification 2 Hot Deserts 45

Desertification – Some possible solutions Afforestation – replanting trees in areas where they’ve been cut down. Reduce the amount of urbanisation is ‘fringe’ areas close to the edge of deserts. Change farming techniques so that less water is extracted from the ground. Reduce the amount of over cultivation to allow the ground to recover Extreme Environments What Challenges do hot deserts pose? Desertification 3 Hot Deserts 46

Some of the other challenges that Hot Deserts Pose:  Drought – This is caused by lack of water of a long period of times causes drought - Crops may fail.  Famine – This is caused by drought. Large numbers of people are not able to access food/water.  Cultures – Over time, cultures change. The Bedouin for example, find it more and more difficult to maintain their traditional way of life. Many cultures have dies out. This is sometimes due to desertification, there are not enough resources to support the Bedouin. Extreme Environments What Challenges do hot deserts pose? Hot Deserts 47