Why Is Australia Mostly Desert?
The climate in the Outback is dry, hot, with lots of duststorms and insects and little rain
- Normally, rain-bearing winds blow across the Pacific ocean towards Australia.
- Australia has a mountain range which borders the coast - it is called the Great Dividing Range.
- These mountains cause the air to rise and cool rapidly. This leads to condensation and then rain.
- As the air descends from the mountains, it is drier.
- This creates a 'rain shadow' and results in low rainfall in western areas.
- The further west the winds blow, the drier they are - so the driest areas are in Western Australia.
25 days of rain per year
El Nino is a reversal of normal air currents across the Pacific Ocean & Australia - it brings drought to Australia every 5-7 years.
Effects Blue=Short term Red=Long term
- Farm Incomes fall
- Abandoned Farms
- Rural Communities Destroyed
- Plant species die out (eucalypts)
- Rainfall to drop by 20-40% by 2070
- Exports dragged down due to drought
- 14% of birds & 25% of mammals could be extinct by 2100
- Winter crops failed, seeds sown but no rain to germinate
- Irrigation water reduced
- Dust storms water shortages
- Farmers lost 80% of income
- High temperatures, low rainfall
- Collapsed power lines
- Reduced soil fertility
- Contamination of water
- Destruction of land/property
- Ban housing in high risk areas
- Water Bombs
- Lack of rain/Overuse of underground water
- Overgrazing/Intensive farming/Bad farming practices (using too much fertiliser)
- Wetlands dry up
- Plants and animals die/Crop failure
- Increased bush fires
- Land degradation and desertification
- Property and job losses
- Food inflation/Water rationing
- Forcing some rivers to flow inland
- Reducing clearing of land
- Developing drought resistant (GM) crops
Soil can be so poor that people in villages cannot grow crops to provide food for themselves. Some causes are:
OVERGRAZING - Grassland is under pressure from the animals people keep.
DEFORESTATION - Trees are being cut down for fuel so soil isn't protected.
DEGRADATION - Farmers have to grow more food for more people so the soil is put under too much pressure.
- Local farmers have built diguettes in the Sahel region of Africa. A diguette is a line of stones, laid along the contours of sloping land. It slows down rainwater and gives it a chance to soak into the ground. The diguettes also trap soil which builds up behind the stones. Soil erosion is therefore reduced.
- In the village of Siguin Vousse almost everyone has improved crop yields and families now feed themselves. Over 400 villages in Burkina Faso have now built diguettes to help with farming.
Solutions: Artesian Water/Underground
- In driest parts of Australia people have adapted by building Artesian pumps which are used to extract ground water from deep underground
- This technology is important in an already dry climate that can suffer droughts
- Air pressure is used to force water out through a pump
- People have dugouts and houses underground, cut into solid rock where daytime heat and night-time cold are evened out
The Prairie Hotel, Parachilna
- The building is 1m below ground and cooled by surrounding rock
- Solar panels generate electricity for lighting and fans, no air conditioning needed
- Kitchen and bathroom water is recycled as 'grey water' for watering the gardens
Climate change could reduce African crop yields by 10% or more and 70% of the population in Africa relies on farming to make a living! How could Africa deal with this?
-Charities and voluntary organisations like Oxfam could help Africa to ADAPT to climate change.
- In Zambia, Oxfam has trained people to use conservation farming.
- Crop yields have been increased through a multi-cropping programme.
- This system involves the growing of several species all in the same area.
- As well as increased output this layered vegetation approach improves soil quality and reduces moisture loss.
- Work is evenly spread over the year.
- If one crop fails there are others, so no one starves and not all income is lost.
- Only small areas are dug or ploughed, so not risk of erosion.
- Moderate but constant farm work-good for weak who were otherwise unable
How Animals Have Adapted
Red Kangaroo-Largest marsupial
- It survives by hopping to find food in the sparsely vegetated desert. This is a fast, energy efficient form of travel.
- It feeds at dawn/dusk when the air is cooler and it sleeps during the heat of the day.
- It licks saliva onto its skin to aid the cooling process.
- It burrows into the soil to find cooler ground to stand and lay down on.
- To escape desert heat, digs burrows/hides in deep rock crevices. It emerges from these to hunt.
- It hibernates from May to August to avoid cold (Australia's winter is during this time!)
- It has low moisture needs and can obtain most from its prey.
The Bilby-A small marsupial
- It is nocturnal so it shelters from the daytime heat and avoids dehydration.
- It burrows for moister, cooler conditions.
- It has low moisture needs, obtaining enough from its food (mainly fungi and insects)
How Plants Have Adapted
- They store water in leaves, stems and roots.
- To survive, succulents can very quickly absorb large amounts of water.
- Their leaves and stems are waxy which makes them almost waterproof.
- Water loss during drought almost stops as they slow down their growth.
- Most have spines or are toxic to stop animals trying to get at the waer they store.
- During drought plants of this type shed leaves to prevent water loss through transpiration.
- Some have waxy leaves to prevent water loss.
- These sort of plants have large root systems to get at underground water.
- These plants have a rapid life cycle and die after seeding, and only survive one season
- Their seeds last for years and only start growing when soil moisture is high.
- Most start growing during Autumn - after any rainfall and before the cold sets in.
- The lifestyle can and has taught us a lot about adapting to extreme environments:
- There is a growing 'native foods' industry in Australia, including selling of fruits (bush tomatoes, desert limes), seeds, nuts, grubs (witchety grubs are eaten cooked or raw!) and meat (kangaroo, crocodile).
- Aborinal people are traditionally Hunter Gatherers - they find edible plants and animals.
- They have done this by building dams to catch fish, creating conditions that grubs can live in and using fire to drive out animals that they can then hunt
- They developed many crafts, music and arts which were primarily based on hunting (such as using boomerangs) or tribal celebrations (playing the didgeridoo).
Unfortunately many of their customs and stories were only spoken, never written, so valuable knowledge is being lost.
Threat Of Tourism
Uluru (Ayers Rock) is a massive tourist attraction. People visit because of the spectacular landscape and because they are interested in aboriginal culture.
PROBLEMS OF TOURISM
- Aboriginal culture can be exploited to provide entertainment. Paintings are produced to suit visitors' tastes, rather than express culture.
- Toursits may leave without learning a thing about aboriginal culture or beliefs. People come for the 'experience' (the sunset over Uluru). Some may even climb the rock, even though it's agaisnt Anangu beliefs to climb Uluru.
- The Anangu have no part in the management or development of the tourist resort where most people stay.
- Tour guides often ignore awkward aboriginal history - they don't want to let peole know about the bad things that have happened. E.g. 90% of aboriginals were slaughtered during the first 60 years of British rule
BENEFITS OF TOURISM
Provides jobs, brings money and raises cultural awareness
How Tourism Is Changing
- New Uluru Aboriginal Culture Centre
- Educates visitors about aboriginal people
- Displays photos/videos/spoken histories/aboriginal language learning/artefacts
- Aboriginal led guided outdoor walks about bush food
- Income goes to Anangu community
- 30 aboriginal people work in park
- Management dominated by aboriginal owners
Global agreements could MITIGATE (reduce) climate change by cutting emissions of CO2.
In 1997 the Kyoto Summit was held to cut greenhouse gas emissions by 5.2% by 2012
141 countries signed, but 181 had signed by 2008
How Life Is Changing
The aboriginal people of central Australia have experienced many changes over the past two years. In some ways there culture has been threatened by growing tourism (1) which some believe has exploited their culture, turning it into a ‘disney’ attraction (2). However, more recently, growing media coverage has led to a growing interest in traditional aboriginal foods (3) which has lead to the creation of employment opportunities in traditional farming and hunter/gathering (4). Tourism has also lead to improvements in transport and communication networks (5) which have brought remote aboriginal societies closer to ‘western’ civilization. These links have lead to products such as alcohol, tobacco, and drugs being used and the social problems associated. (6)
Lots now work in mining industry