SEC23 GEOG Chapt8 Water
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SEC23 GEOG Chapt8 Water

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WATER

WATER

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    SEC23 GEOG Chapt8 Water SEC23 GEOG Chapt8 Water Presentation Transcript

    • CHAPTER 8 Water Resources
    • Learning Outcomes
      • 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
    • Lead-in: Water Raiders (Suggested Answers)
      • The supply of water is limited in this village. It is likely that the village has only one water source, possibly a well, and water has to be rationed among the villagers. This is unlike in the modern city where clean water is readily available from pipes and taps. It could also be possible that a drought has occurred and the available water has to be rationed carefully.
      • Yes, this situation is possible in Singapore in the future. In the past, Singapore had experienced prolonged droughts and water rationing had taken place. In an event of a protracted dry spell, there may be water rationing.
    • Lead-in: An African Woman’s Journey
      • Extension Activity
      • 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. What do you think can be done to help solve the problem of water shortage in these places?
    • Water as a Scarce Resource
      • Much of the world’s water is used in households, industries and agriculture.
      • With the rapid growth in the world’s population and industrialisation, water consumption is increasing globally.
      • However, the amount of fresh water on the Earth available for human use remains limited.
      • This situation whereby there is a shortage of water to meet the needs of people is known as water constraint .
      • More than one-third of the world’s population live in countries that are facing water constraint.
    • Reasons for Water Constraint
      • Limited supply of fresh water
      • Only about one 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.
    • Reasons for Water Constraint
      • Limited supply of fresh water
      • Uneven distribution of fresh water
      • Some countries have an abundant supply of water, while others suffer from a lack of it.
      • For example, Canada has half a percent of the world’s population but has 20 percent of the world’s fresh water supply. However, China with 21 percent of the world’s people, has only seven percent of the world’s fresh water supply.
      • Uneven distribution of fresh water in the world may be due to differences 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.
    • Reasons for Water Constraint
      • Limited supply of fresh water
      • 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
    • Reasons for Water Constraint
      • Rising demand for water
      • 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.
    • Reasons for Water Constraint
      • Rising demand for water
      • 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).
    • Reasons for Water Constraint
      • Rising demand for water
      • 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.
    • Reasons for Water Constraint
      • Rising demand for water
      • 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.
      A jacuzzi A dish washer
    • Responses to Rising Demand for Water
      • Increasing the price of water
      • As a response to the rising demand for water, countries can increase the price of water to discourage people to use water unnecessarily.
      • But this may not be the best solution to deal with the rising demand for water.
      • The reason is that the rich will be able most likely be able to afford the price increase and continue to use the amount of water they desire. On the contrary, the price increase will disproportionately affect the poor.
    • Responses to Rising Demand for Water
      • Increasing the supply of water
      • The supply of water can be increased by increasing catchment areas, purchasing water from other countries through international agreements and the use of technology like water recycling and desalination.
      • Increase catchment areas
      • A catchment area refers to an area over which rain falls and is collected.
      • Increasing water catchment areas will increase the collection and supply of water.
      • An example of a catchment area is the Central Catchment area in Singapore. Nature reserves can also serve as catchment areas.
    • Responses to Rising Demand for Water
      • Increase catchment areas
      • Water in catchment areas is treated before it is supplied to homes and industries.
      • Increasing catchment areas also helps to keep the cost of water treatment down because rainwater is cleaner and easier to purify than used water or sea water.
      • Furthermore, more forests are also conserved when land is set aside for catchment areas. People can have access to nature and more recreational areas.
      • However, countries facing land constraint like Singapore may face difficulties in setting aside land for catchment areas as land is needed for roads, houses and industries.
      • In addition, 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.
    • Responses to Rising Demand for Water
      • International agreements
      • Water can also be obtained from other countries through international agreements. An 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, one in 1961 and another in 1962. The 1961 agreement expires in 2011 while the 1962 agreement expires in 2061.
      Special/Express stream only
    • Responses to Rising Demand for Water
      • International agreements
      • International water agreements may not be the best solution for obtaining water in the long-term as these 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.
      Special/Express stream only
    • Responses to Rising Demand for Water
      • Use of technology: Recycling water (Water reclamation)
      • Technology can be used to create new sources of water. 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.
    • Responses to Rising Demand for Water
      • Use of technology: Recycling water (Water reclamation)
      • At the start of the water reclamation process, used water from households and factories is channelled to water reclamation plants for treatment of impurities.
      • The end product is known as recycled water or reclaimed water .
      • The treated water can be treated further at industrial water works to produce industrial water. Industrial water is mainly used to wash and cool machinery in factories.
    • Responses to Rising Demand for Water
      • Use of technology: Recycling water (Water reclamation)
      • With the advancements in technology, used water can be treated to become clean drinkable water or potable water. An example is Singapore’s NEWater.
      • The process of water recycling goes through the stages of microfiltration, reverse osmosis and UV disinfection.
    • Responses to Rising Demand for Water
      • Use of technology: Recycling water (Water reclamation)
    • Responses to Rising Demand for Water
      • Use of technology: Desalination
      • In many dry regions of the world, or in places where water supply is contaminated, desalination is often used to convert sea water into drinkable water. An example is Saudi Arabia.
      • One method of desalination is distillation when water is boiled and the water vapour is collected and condensed into fresh water.
      • The distillation process is costly as it consumes a lot of energy.
      • A more recent method of desalination is reverse osmosis.
    • Responses to Rising Demand for Water
      • Use of technology: 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 accustomed 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.
    • Responses to Rising Demand for Water
      • Conserving water
      • Water conservation refers to the careful use of water resources to ensure that wastage is kept to a minimum.
      • Water conservation emphasises the saying ‘Prevention is better than cure’. It helps reduce the risk of future water shortages, delays the need to develop or upgrade facilities to increase water supply and helps households and industries save on water bills.
      • Public campaigns can be launched to educate the public about the merits of water conservation.
      • However, ‘habits die hard’ and getting people to change their lifestyles to conserve water may be a difficult task.
      • If everyone cooperates to conserve water, our precious water resources will be able to last longer.
    • Water Supply in Singapore
      • History of water constraint in Singapore
      • The problem of water constraint in Singapore is not new and can be attributed to the constraints of our physical environment and the loss of catchment areas.
      • The supply of fresh water in rivers and catchment areas does not satisfy all our water needs.
      Since the early 20th century, land has been cleared for housing industries in Singapore. However, the government has now recognised the importance of water catchment areas and has aside about half of Singapore’s land for this purpose.
    • 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.
    • Water Supply in Singapore
      • 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.
    • Water Supply in Singapore
      • Methods to increase water supply
      • To ensure that water will be sufficient in the future, the 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 , producing NEWater , and increasing supply of desalinated water .
    • Water Supply in Singapore
      • 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.
      Reservoirs in Singapore
    • Water Supply in Singapore
      • Tap 2: Imported water
      • Buying water from neighbouring countries is another way of increasing water supply.
      • Singapore currently has two water agreements with the Malaysian state of Johor. Both agreements expire in 2011 and 2061.
      • Buying water from other countries may not be the best solution to increasing water supply over the long-term as these agreements can expire and may not be renewed.
      • Therefore, it is important to be self-sufficient and obtain water from local sources.
    • Water Supply in Singapore
      • 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.
      • There are currently three NEWater plants in Singapore.
    • Water Supply in Singapore
      • 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
    • Water Supply in Singapore
      • Policies and campaigns to conserve water supply
      • Imposing water conservation tax to discourage excessive use of water. Households that use more water will pay higher taxes than those that use less.
      • Awareness of the importance of water conservation can be carried out through ‘Save Water’ campaigns, water conservation talks, and water rationing exercises.
      • For example, the PUB has devised the Water Efficiency Labelling Scheme (WELS) and annually give awards (Friends of Water) to individuals and organisations that contribute towards raising awareness about water conservation and water sustainability.
    • Water Supply in Singapore
      • 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.
    • Water Supply in Singapore
      • Is there enough for the future?
      • Domestic water use per person has declined from 172 litres per day in 1995 to 160 litres per day in 2005.
      • As our population and economy continue to grow, it may not be possible to sustain our water supply indefinitely.
      • Therefore, it is very important for us to conserve and value our precious water resources so that we can continue to enjoy it now and in the future.
    • Skills Builder: Suggested Answers
      • China’s water shortage can be attributed to drought, severe water pollution like the discharge of raw sewage into rivers and lakes which makes water unsafe for drinking, and inadequate access to clean drinking water.
      • Some effects of water constraint in China include decline in grain production due to drought, severe health problems such as cancer and deformity in humans caused by water pollution, and illnesses suffered by peasants from drinking poor quality water or water with fluorine above acceptable standards.
      • China can tackle the problem of water constraint by reducing water pollution, enforcing strict laws and regulations and building sewage and water treatment plants. ( Accept other plausible answers. )