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CHAPTER 8 Water Resources

CHAPTER 8 Water Resources. What you will learn. to explain the reasons for water constraint to evaluate the effectiveness of different responses to increasing water supply to examine Singapore’s responses in overcoming the constraints of water supply. Water as a scarce resource.

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CHAPTER 8 Water Resources

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  1. CHAPTER 8Water Resources

  2. What you will learn • to explain the reasons for water constraint • to evaluate the effectiveness of different responses to increasing water supply • to examine Singapore’s responses in overcoming the constraints of water supply

  3. Water as a scarce resource Demand > Supply

  4. Water as a Scarce Resource Supply (Limited supply of freshwater) • Uneven distribution of freshwater • Water pollution Demand (Rising demand for water ) • Population growth • Growth of agriculture • Growth of Industries • Changes in lifestyle

  5. Water as a Scarce Resource Why water is a scarce resource? • Much of the world’s water is used in households, industries and agriculture. • Rapid growth in population and industrialisation = water consumption is increasing globally. • Limited amount of fresh water on the Earth • Water constraint • => The situation whereby there is a shortage of water to meet the needs of people is known as water constraint.

  6. At a glance…… • What would life be like in this country? • Why do you think the villagers need to travel and carry water?

  7. Reasons for water constraint • Limited supply of freshwater • Only about three percent of the water on the Earth is fresh water that is available for human consumption. • Fresh water is found in rivers, streams, lakes and underground aquifers.

  8. 1. Limited supply of freshwater a)Uneven distribution of fresh water • Some countries have abundant supply of water, while others suffer from a lack of it. For example: Canada and China • Difference in climate South America experiences a tropical equatorial climate and has the largest annual water runoff of any continent. 60 percent of its runoff flows through the Amazon River in remote and uninhabited areas. Amman, capital of Jordan, experiences a dry and arid climate.

  9. An African Woman’s Journey In some parts of Africa, people live very far away from their water sources. Getting water for daily needs like drinking, cooking and washing is very difficult. Women and girls have to travel very long distances daily to fetch water from a water source. In these places, water is very precious and scarce.

  10. An African Woman’s Journey What do you think can be done to help solve the problem of water shortage in these places?

  11. Limited supply of freshwater b) Water pollution • Human activities are increasingly polluting fresh water resources. • Humans have dumped untreated sewage from households and factories into rivers and lakes, causing them to be polluted and unfit for human use. A polluted river

  12. Reasons for water constraint 1) Limited supply of water 2) Rising demand for water

  13. 2) Rising demand for water a) Population growth • In the last 80 years, the world’s population has tripled while the world’s demand for water has increased by more than six-fold. • As the world’s population continues to grow, the available supply of fresh water has to be shared among more people. • This will exacerbate the problem of water constraint in many water-scarce countries

  14. 2) Rising demand for water b) Growth of agriculture • With the increase in the world’s population, there is a need to grow more food through agricultural activities. • Agricultural activities consume about 70 percent of the world’s fresh water supply. Fresh water is used to water crops and rear livestock. Globally, irrigation is the biggest user of water (70 percent), followed by industries (20 percent) and urban settlements (10 percent).

  15. 2) Rising demand for water C) Growth of industries • As industries grow, consumption of water increases. • Water is needed for manufacturing and daily operational processes in industries. • For example, water is used to make products, clean and cool machines. A power plant requires large amounts of water to cool its heated power generators. Water is needed to make products like paint.

  16. 2) Rising demand for water d) Changes in lifestyle • As a country develops, people become more affluent and can adopt modern lifestyles of convenience and comfort. • Adopting such lifestyles increases the demand for water.

  17. Responses to Rising Demand for Water

  18. Responses to Rising Demand for Water • Increasing the price of water • > demand for water = Increase the price of water = < discourage people to use water unnecessarily • Is this a GOOD choice?

  19. 2) Increasing the supply of water a) Increase catchment areas • A catchment area refers to an area over which rain falls and is collected. • > water catchment areas = > increase the collection and supply of water. • Example : Central Catchment area in Singapore and Nature reserves

  20. Central Catchment Area in Singapore Locate the areas : ____________

  21. Effectiveness of increase catchments areas • Safe for drinking because water in catchment areas is treated before it is supplied to homes and industries. • Keeps the cost of water treatment down • More forests are also conserved when land is set aside for catchment areas. People can have access to nature and more recreational areas. • Land constraint countries may face problem as land is needed for other uses • As rain is a natural occurrence, in an event of a dry spell like a drought, water levels in catchment areas may decline or the reservoirs may even dry up.

  22. b) International agreements • International agreement on water is an arrangement between two or more countries regarding the supply and use of water resources over a specific period of time. • When signing international agreements, countries negotiate the terms on the buying and sharing of water resources. • Singapore has signed two water agreements with Malaysia= 1961 ( expires in 2011) and 1962 (expires in 2061)

  23. Effectiveness of international agreement • Convenient way of obtaining water • Short term solution as water agreements can expire • When these agreements expire, there is no guarantee that countries will be able to negotiate for a new agreement and that they will have sufficient water to meet their needs • Therefore, it is important to be self-reliant and self sufficient.

  24. c) Use of technology: Recycling water (Water reclamation) • Technology refers to the knowledge, skills and tools that people use to meet their needs. • Recycling water or water reclamation and desalination are products of technology to increase the supply of water. • During water reclamation,impurities are removed from waste water through a treatment process.

  25. c) Use of technology: Recycling water (Water reclamation) Singapore’s NEWater.

  26. c) Use of technology: Desalination • Desalination-> process of removing salt from seawater • Methods: i) Distillation : when water is boiled  the water vapour is collected  condensed into fresh water. • The distillation process is costly as it consumes a lot of energy. • ii) Reverse Osmosis= recent tecnology of desalination

  27. c) Use of technology: Recycling water (Water reclamation)

  28. Effectiveness of the use of technology • Recycling water or water reclamation and desalination are still very costly and requires large amounts of energy. • Improvements in membrane technology may help reduce costs and increase the efficiency of water reclamation and desalination in the future. • Furthermore, people may not be used to drinking reclaimed or sea water as it tastes slightly different from water obtained from traditional sources. • In Singapore, for example, to resolve this problem, NEWater is piped into reservoirs before it is channelled to homes and industries

  29. 3) Conserving water • Water conservation careful use of water resources to ensure that wastage is kept to a minimum. • Public campaigns can be launched to educate the public about the merits of water conservation. • Is it effective?

  30. 3) Conserving water

  31. Water Supply in Singapore History of water constraint in Singapore Problems Constraints of our physical environment Loss of catchment areas due to massive clearance to make way for housing and development

  32. Water Supply in Singapore Growing demand for water • The growth of Singapore’s population and industry has increased the demand for water. • This demand is expected to rise further as the economy develops more high-tech manufacturing industries which require large amounts of clear water for their industrial processes. • Increasing wealth, growth in the economy and changes to our lifestyle have caused us to use water at an increasing rate.

  33. Water as a strategic resource • Water is very important to our survival as a nation. • Many of our households, industrial and business activities need water. • Without clean water, the health of our people will also be affected. • Therefore, if we do not manage our water supply well, it will increase our vulnerability which puts us in a weak or unfavourable position.

  34. Methods to increase water supply • Public Utilities Board (PUB) has implemented a strategy called the ‘Four National Taps Strategy’. • This strategy is targeted at increasing water supply through four methods: • Getting water from local catchment areas, • Buying imported water c) Producing NEWater d) Increasing supply of desalinated water.

  35. Tap 1: Water from local catchment areas • Over the years, reservoirs have been constructed to increase local catchment areas. There are now currently 14 water reservoirs in Singapore. • By 2009, with the completion of the Marina Barrage, Singapore’s total water catchment area will increase from half to two-thirds of the island. • In addition, stormwater collection ponds have been constructed in some housing estates to collect rainwater and channel them to various reservoirs.

  36. Local catchment areas in Singapore

  37. Tap 2: Imported water • Singapore currently has two water agreements with the Malaysian state of Johor. Both agreements expire in 2011 and 2061.

  38. Tap 3: NEWater • Advanced membrane technology in water reclamation can be used to treat used water to produce very high quality water known as NEWater. • It is supplied mainly to wafer fabrication plants, industrial estates and commercial buildings

  39. Tap 4: Desalinated water • Singapore’s first desalination plant started operations in Tuas in 2005. The plant uses the reverse osmosis method to treat sea water. • Although the cost of building and operating the plant is high, it can supply up to 10 percent of our demand for water. • The cost of desalination is expected to come down over time as technology improves and becomes more cost-efficient. Tuas desalination plant

  40. What can you do to conserve water?

  41. Policies and campaigns to conserve water supply Policies and campaigns to conserve water supply Below are some ways to conserve water: 1. Install water-saving devices. 2. Take shorter showers. 3. Turn the water tap off when soaping yourself or brushing your teeth. 4. Monitor your water bills and check for leaks regularly. 5. Do a full load of laundry at a time. 6. Wash your car with a pail of water, not a hose. 7. Don’t litter the drains and canals. 8. Enjoy our reservoirs but keep them pristine

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