Water: Reasons for Water Constraint & Responses to Rising Demand for Water

Objectives Reasons for water constraints Responses to water constraints Case study: Singapore

Reasons for Water Constraint http://www.google.com.sg/imgres?q=lack+of+water&hl=en&sa=X&biw=1280&bih=622&tbm=isch&prmd=imvns&tbnid=YNnQ8tj7C_9iLM:&imgrefurl=http://www.world-crisis.com/analysis_comments/764_0 http://searchandhra.com/english/wp-content/uploads/2008/12/water-tanker-cartoon.jpg

Water Constraint Water supply is limited Water consumption (demand) is increasing Hence there is a water shortage

Factors affecting Water Supply Limited supply of fresh water Uneven distribution of fresh water Water pollution Factors affecting Water Demand Population growth Growth of agricultural Growth of industry Changes in lifestyle

Limited supply of fresh water Only 1 percent of total amount of water on earth is fresh water http://snr-1349.unl.edu/images/waterdist.gif

Uneven distribution of precipitation Low precipitation in areas such as North Africa and the Middle East results in the scarcity of water in these regions.

Water Pollution Man’s activities affect the quality of water Waste from factories and homes dumped in rivers Deforestation causes soil erosion, which pollutes rivers Sedimentation in stream

Citarum River – West Java, Indonesia

Reasons for the Rising Demand for Water Population growth Growth of agricultural Growth of industry Changes in lifestyle

Population Growth In the last 80 years Population increased by 3 times Water demand increased by 6 times http://m5.paperblog.com/i/8/83906/population-explosion-can-the-planet-cope-with-L-uupk9_.jpeg http://s3.hubimg.com/u/590578_f520.jpg http://phillips.blogs.com/photos/uncategorized/26_chinese_crowd.jpg

Growth of agriculture Increasing world need for food 69% of available freshwater used for irrigation, rearing livestock http://www.catskill-merino.com/images/gallery/ http://www.agricorner.com/wp-content/uploads/2011/12/irrigation

Growth of industries 15% of the earth’s freshwater is used in industries for : Cleaning machines Cooling machines As a raw material in the food, chemical and paper industries

Changes in lifestyle People have become more affluent Can afford modern appliances, eg washing machines, long baths, air conditioners This increases demand for water 15% of the world’s freshwater is used in household settings

Summary Factors affecting Water Supply Factors affecting Water Demand Limited supply of fresh water Uneven distribution of fresh water Water pollution Factors affecting Water Demand Population growth Growth of agricultural Growth of industry Changes in lifestyle

Responses to Rising Demand for Water Increasing price of water Increasing supply of water Conserving water

Increasing the Price of Water Water prices influence the use of water determined by government officials, water companies, environmental groups and interest groups of consumers Increasing price of water will slow down the rising demand for water.

Expensive water everywhere! Australia: http://www.abc.net.au/news/2010-07-15/water-to-get-more-scarce-more-expensive/905672 China: http://online.wsj.com/news/articles/SB10001424052702303870704579297410328066466

Increasing Water Supply Increase catchment areas International agreements Use of technology

Increasing catchment areas A catchment area is also known as a drainage basin. It is the area bounded by hills or mountains. Surface runoff collects in a catchment area and water is carried by a river and its tributaries to the sea.

Managing catchment areas Restrict logging activities and carry out reforestation programmes Initiate large water projects that help increase water supply eg. Three Gorges Dam project in Centre China

International Agreement

International Agreement Regional tensions and conflicts among nations can arise over the use of the shared water resource. Affected countries will suffer from inefficient use or decrease in water supply. International agreements help to settle or prevent cross-border disputes over water resources.

Examples of International Water Agreements Nile Basin Initiative: 9 African countries that the Nile River runs through Mekong River Commission: 4 SE Asian countries that the Mekong River runs through

Mekong River

Nile River – it’s so long I can’t show you the whole thing clearly!

Use of technology Desalination Recyling water (water reclamation)

Desalination A process that removes salts and other impurities from saltwater. 2 methods: Distillation Reverse osmosis

Distillation Seawater is heated – water vapour is collected and channeled into condensers Incoming seawater is used to cool condensers, on which water vapour will condense to form pure water Pure water is collected and used

Reverse Osmosis Seawater is pumped at high pressure through a special membrane In this process, dissolved salts are separated from the water This occurs because the membrane is very dense, and only allows water molecules to pass through it.

Water Reclamation Reclaiming water is the treatment of wastewater for reuse.

Water Conservation Water conservation can take place in domestic, industrial, commercial and agricultural sectors. Public education helps to reduce water wastage. Posters, booklets, flyers, programmes, events.

Water Conservation at Home

Water Conservation at Home

Case study: Water Supply in Singapore http://www.epa.gov/region07/kids/images/drnkwtr1.jpg

The Supply of and Demand for Water in Singapore The supply of water

The Supply of and Demand for Water in Singapore The demand for water Sources of water supply: Local water catchments Imported water Reclaimed water (NEWater) Desalination Water usage pattern in Singapore households

Ensuring a Sustainable Water Supply in Singapore Mandai Reservior Sarimbun Reservior Kranji Reservior Upper Seletar Reservior Lower Seletar Reservior Upper Pierce Reservior Lower Pierce Reservior Payan Reservior Jurong Lake Bedok Reservoir MacRitche Reservior Pandan Reservior Tengeh Reservior Local catchment areas

Water from our local catchment areas 14 reservoirs supply us with clean water. Half of Singapore’s total area is used as water catchments By 2009, the total catchment will be two-thirds of Singapore. The Reservoir Integration Scheme The Marina Barrage An artist’s impression of the Marina Barrage

Imported Water Water is Imported from Malaysia to supplement our water supply. Two agreements signed between Malaysia and Singapore in 1961 and 1962 are in force up to 2011 and 2061 respectively.

Reclaimed Water Through new technology to further treat the effluent water large volumes of used water has been reclaimed since 2002. NEWater is mainly used for industrial and commercial purposes with a small amount blended with reservoir water. With NEWater, Singapore’s water supply has become more sustainable.

Desalinated Water Construction of Singapore’s first desalination plant took place in 2004 and began to operate in 2005. It can supply 10% of our demand for water.

The Four National Taps Strategy Water conservation plan: Pricing water to reflect its strategic importance and scarcity Educating the public to use water efficiently Getting commercial and industrial premises to install water-saving devices Encouraging use of alternative sources Imposing fines on water wastage and unauthorised water usage.