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Topic 4-Lesson 1

Topic 4-Lesson 1. Australia’s Aquatic Past. Introduction.

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Topic 4-Lesson 1

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  1. Topic 4-Lesson 1 Australia’s Aquatic Past

  2. Introduction • We already know that Australia is very old. We have a rock record going back 4.1 billion years. In that time Australia has undergone changes. The Continent has build up over time in a west to east direction and most of the rocks formed in aquatic environments as sediments settled at the bottom of lakes, lagoons and seas.

  3. Activity • Complete activity 3.12 pg 102 Prelim Spotlight Text

  4. Water Pollutants • Pollutants are any substance that is harmful to the environment or life. Water pollutants are categorised into the following types: • Oxygen-demanding • Pathogens • Synthetic organic compounds • Nutrients • Inorganic chemicals • Sediments • Radioactive • Thermal discharge

  5. Oxygen-Demanding Substances • Organic material that is not completely decomposed. As this material enters a body of water is continues to decompose and use up oxygen from the water. This reduces the levels of dissolved oxygen for plants and animals. Examples of this is untreated sewage and dead animals.

  6. Pathogens • These are organisms that can cause disease if found in water bodies. In 1998 protozoan parasites Giardia and Cryptosporidium contaminated Sydney’s water supply. These organisms can cause intestinal cramping and diarrhoea. These waterborne diseases are common in Third World countries and can kill you. Cholera and typhoid are examples that are fatal.

  7. Synthetic Organic Compounds • These are human manufactured chemicals made mostly of carbon and hydrogen. Petroleum is the most common type which floats on top of the water and prevents light penetration and covers shorelines. This type of pollution can blind, poison and drown fish, birds and other animals.

  8. Nutrients • These are natural or synthetic substances that promote plant growth. These typically contain nitrogen and or phosphorus. Examples include manure, humus, detergents and fertilisers. This type of pollution can promote the growth of non native plants and algal blooms.

  9. Inorganic Chemicals • These can be pesticides and herbicides or substances released by industrial processes. They can interfere with normal functions of individual organisms or entire ecosystems. In humans this type of pollution can cause cancer, skin disease, organ failure and disorders of the nervous system, immune system and reproductive system. An example of this is heavy metals released by industry.

  10. Sediments • Water in natural environments is usually quite clear. Erosion transports sediments into rivers and streams making them murky. During floods this naturally happens however due to land clearing more sediments are washed into rivers and streams. This can clog the gills of fish, block the suns rays and interfere with gases dissolved in the water.

  11. Radioactive Substances • This is currently a problem in some Northern Hemisphere locations who use nuclear reactors to generate electricity. Radiation damages DNA and results in mutations and diseases. Australia’s uranium mines pose the most likely source of low level radioactive contamination.

  12. Thermal Discharge • Some industries use water as a coolant and release the waste water into lakes, streams and rivers. This waste water is free of pollutants but is hot or warm and can kill plants and animals. We know hot water holds less dissolved gas so it can suffocate fish and plants.

  13. Sources of water pollution • The main sources of water pollution includes sewage, agriculture, industrial waste and garbage. Water is arguably out most vital natural resource and it’s important to protect and conserve our water supplies. • How can you protect waterways?

  14. Activity • Read ‘How you can protect waterways’ section of Prelim Spotlight Text page 105. • Discuss Table 3.3 pg 106 Prelim Spotlight Text • Discuss Activity 3.15 (Students need to complete for homework)

  15. Review • Pollutants are any substance that is harmful to the environment or life. Water pollutants are categorised into the following types: • Oxygen-demanding • Pathogens • Synthetic organic compounds • Nutrients • Inorganic chemicals • Sediments • Radioactive • Thermal discharge

  16. Homework Read pages 101-105 Prelim Spotlight Text Update electronic vocabulary Complete Activity 3.15 pg 107 Prelim Spotlight Text Complete DOT Point 4.1-4.2

  17. Topic 4-Lesson 2 Australia’s Aquatic Past

  18. Review • Pollutants are any substance that is harmful to the environment or life. Water pollutants are categorised into the following types: • Oxygen-demanding • Pathogens • Synthetic organic compounds • Nutrients • Inorganic chemicals • Sediments • Radioactive • Thermal discharge

  19. Water Recycling • The ideal situation for water use would be to have two water supplies. One for drinking and one for all other uses. It’s very expensive to produce water safe for human consumption and according to Sydney Water, more than half the treated water is used for washing and watering gardens.

  20. Water Recycling • Water authorities in Australia are moving towards water recycling to try and reduce water consumption. Recycled water (non-potable water) is not suitable for drinking, cooking or bathing but can be used more than once for other things.

  21. Water Recycling • Consumers would have to add an additional set of pipes for the non-potable water which would initially be expensive but the recycled water would be cost about 1/3 the price of potable water.

  22. Water Recycling • In 2001 the sewage treatment plant at Rose Hill in Sydney’s north west was the first to produce non-potable water for public use. They chose to do it here because it was a new development area. The cost of laying a non-potable set of pipes at the same time as the potable set was not a great deal more. • Do you think this should be mandatory for all future development sites?

  23. Benefits of Conservation and Recycling • Reducing water bills • Less chance of water restrictions • Reducing the need for new dams • Recycled water contains more nitrates and phosphates which would reduce the need for fertilisers on lawns and gardens • Reduces discharge of nutrient-laden water into rivers • Saves drinking water • Reduces the impact of urban development on waterways

  24. Ground water • Ground water represents a large component of the global fresh water. It’s the larges reservoir for drinking water and is therefore an important natural resource that needs to be managed carefully.

  25. Ground Water • Ground water is held within the pores of saturated rocks and sediments below the surface. It comes from rain soaking through the soil and into underlying rocks where it slowly makes its way down hill due to the force of gravity.

  26. Ground Water • The movement of ground water is influenced by the types of rocks is encounters. For example, porous rocks like sandstone act like reservoirs for ground water. Non-porous rocks like shales act as barriers. See Figure 3.31 Prelim Spotlight Text pg 110.

  27. Ground Water • The top layer of groundwater is called the water table. This varies in depth depending on the geology and precipitation of an area. If conditions are right, this water can exit the ground and form natural lakes, springs, swamps and rivers. Groundwater can sustain a river system during dry periods.

  28. Problems with Ground Water • The quality of ground water is naturally variable. Some aquifers release water that is very clear and has few dissolved minerals while others can be murky and saline.

  29. Problems with Ground Water • Saltwater intrusion and pollution can negatively affect ground water. Saltwater intrusion happens when we remove water from Aquifers and salty water then fills this space.

  30. Problems with Ground Water • Pollution of ground water is a serious problem. Most pollutants move through groundwater slower than water. If safe practices are not in place for everyone, ground water can be polluted by a number of activities. • Waste disposal • Agriculture • Chemical, petroleum and transport • Mining

  31. Problems with Ground Water • The treatment of polluted ground water is expensive and time consuming. One way this is done is pumping the water to the surface, treating it, and then pumping it back into the aquifer.

  32. Review • The ideal situation for water use would be to have two water supplies. One for drinking and one for all other uses. • Ground water represents a large component of the global fresh water. It’s the larges reservoir for drinking water and is therefore an important natural resource that needs to be managed carefully. • The movement of ground water is influenced by the types of rocks is encounters. • Saltwater intrusion and pollution can negatively affect ground water. • The treatment of polluted ground water is expensive and time consuming.

  33. Homework Read pages 108-112 Prelim Spotlight Text Update electronic vocabulary Complete ‘To Think About’ Prelim Spotlight Text pg 113 Complete DOT Point 4.3-4.5

  34. Topic 4-Lesson 3 Quiz

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