Wednesday, 3 October 2007
Geography Chapter: Water ResourcesY
Water Resources
Water as a Scarce Resource
-there's a limited supply of fresh water on earth
-but we need it for hoseholds, industries and agriculture
-with the rapid growth of industrialisation, the global rate of water consumption is increasing
Water Constraints
It is a situation whereby there is a shortage of water to meet the needs of people. More than one-third of the world's population live in countries facing water constraint.
Reasons:
1.Limited supply of fresh water
-only about 1% of the earth's water is fresh water that is available for consumption
-fresh water is found in lakes, streams, rivers and underground aquifers
Uneven distribution
-some countries have abundant supply of fresh water while others suffer from a lack of it
-uneven distribution may be due to the differences in climate
e.g. Canada has half a percent of the world's population but has 20% of the world's fresh water supply.
Whereas China with 21% of the world's population has only only 7% of the world's fresh water supply.
Water pollution
-human activities are increasingly polluting fresh water resources
-humans dump untreated sewage from households and factories into water bodies, causing them to be polluted and unfit for human use
2.Rising demand for water
-further contributes to the problem of water constraint
Population growth
-the world's population has tripled in the last 80 years, causing the world's demand for water to increase more than 6 times more than it was before
-more people = same amount of supply have to be shared by more people
-this will exacerbate the water constraint problems in many water-scarce countries
Growth of agriculture
-population growth = need to grow more food through agricultural activities
-agricultural activities consume about 70%of the world's fresh water supply as fresh water is used to water crops and rear livestock
Growth of industries
-growth of industries = consumption of water increases
-because water is needed for manufacturing and operational processes in industries like cleaning and cooling of machines
Changes in lifestyle
-more countries are developed, people become more affluent and can adopt to modern lifestyles of convenience and comfort
-such lifestyles increases the demand of water
e.g. using a dish washer to wash dishes requires more water, enjoying comfort in a jacuzzi bath
Responses to Rising Demand
1. Increasing the price of water
-to discourage the use of water unnecessarily
-may not be the best solution as the rich can still afford and continue to use the amount they desire; whereas the price increase will disproportionately affect the poor
2.Increasing the supply of water
Increase catchment areas
-catchment area refers to an area which rainfall is collected
-increase the supply and collection of water
e.g. Singapore's Central Catchment area and Nature reserves. (examples of catchment areas)
-water in catchement area is treated before being supplied to industries and households
-helps to keep cost of water treatment low as rainwater is cleaner and easier to purify than sea water
-forests are also conserved when land is set aside for catchment areas. people can have more acces to nature and more recreational areas
BUT
-countries facing land constraint like Singapore may have difficulty setting aside land for catchment areas as land is needed for roads, houses and industries
-rain is a natural occurrence; if there's a drought, water levels in catchment areas may decline and reservoirs may even dry up
International agreement
-water can be obtained by other countries through international agreement
-when signing such agreements, countries negotiate the terms on the buying and sharing of water resources
-Singapore has signed 2 water agreements with Malaysia: 1961 agreement (expires in 2011) and the 1962 agreement (expires in 2061)
-may not be the best solution as agreements may expire and there is no guarantee that the other country has sufficient water to meet their own needs
Use of technology
->Recycling water (or water reclamation)<-
->impurities are removed from waste water through a treatment process
->with advancement in technology, used water can be treated to clean and drinkable water or portable water (e.g. NEWater, read it up on page 128 of Geog txtbk)
=>Desalination<=
=>used in many dry regions of the world, or in places where water supply is contaminated,this process is used to convert sea water into drinkable water (e.g. Saudi Arabia)
=>desalination is actually distillation of sea water
=>it is costly and comsume a lot of energy
Use of technology is very costly and requires large amounts of energy. Improvements in membrane technology (NEWater) may help to reduce costs and increase efficiency of water reclamation and desalination in future. Moreover, people may not like the processed waste water as it taste slightly different from traditioanally-obtained water. The Singapore government resolve this problem by piping NEWater into reservoirs before channelling it to homes and industries.
Conserving water
-to use water carefully and ensuring wastage is kept to a minimum
-emphasises on "Prevention is better than cure"
-helps reduce risk of future water shortages
-delays the need to upgrade facilities to increase water supply
-helps household and industries save on water bills (tell mummy this!)
-public campaigns can be launched to educate the public about the merits of water conservation
-it may be diificult to change people's lifestyle, but if everyone cooperates, our precious water resources will be able to last longer
*Read Case Study on Singapore from page 131 to 136 of Geog txtbk, it'll help when you need to state examples, also easier for you to relate as you're living in Singapore!