s1 ge slides - water

Water Supply

Chapter 4(Textbook pg 120-175)

Uses of Water

Domestic use

(8%)

- Consumption- Hygiene- Amenity

Economic use

Industrial sector /

manufacturing(22%)

Water is used for the manufacture, maintenance &

cooling of generators

Tourism industry

Agriculture(70%)

Water is used for growing crops (eg. rice, rubber, coffee

& cotton)

Water FootprintThe total volume of water (in

cm3) used to produce the goods and services for a person in a year.

With your partner…Within one minute, let’s try the question on the bottom of page 129 of your textbook

Not everybody has access to clean water

Over 1 billion people in the world do not have enough clean water to drink and this number is predicted to increase

Why are there countries with

water shortages?

The Hydrological Cycle

Isn’t water a renewable resource?

TranspirationPrecipita

tion

Infiltration

Groundwater flow

Evaporation

Surface

runoff

Condensation

Sea / Ocean

Land

surface

_____________________

________

_____________

_________

___________

_

__________

Sea / Ocean

Land

surface

Water ShortageWater usage > supply

Eg. New Delhi in India faces water shortage due to the country’s growing populationDemand

(in peak summer months)

But city only gets…

4.35 million m3 a day

3.22 million m3 a day

Water Shortage

Imagine you live in New Delhi. You have to queue up at a water tanker everyday to

obtain your daily supply of water for drinking and

bathing…How would you feel?

Why are there water shortages?Most of earth’s water is in the oceans

(97.2%), which is too salty to use or drinkOnly 2.8% of earth’s water is freshwater

To understand why are there water shortages…First, let’s look at

the distribution of water on earth

Ocean

Ice caps, glaciers, rivers &

lakes

Ground

water

Ocean

Ocean water is replenished by precipitation and rivers that flow into

the oceans

Groundwate

r

• People mostly use surface freshwater because it is easier to access than groundwater

• People are increasingly drawing from groundwater in places where there is insufficient surface fresh water

Land surface 2) Some rainwater infiltrates the ground

1) Rain falls on the ground

3) Water then fills up the empty spaces and cracks. 4) Water is thus stored in the ground as groundwater.

Underlying rocks and soil particles

Land surface 2) Some rainwater ________the ground

1) Rain falls on the ground

3) Water then fills up the _____________ & _______. 4) Water is thus stored in the ground as ____________.

Underlying rocks and soil particles

Groundwate

r

• Many countries use groundwater for irrigation

• Most abundant supply of groundwater is found in South America and Africa


lakes

Ice cap: A thick, continuous mass of ice which covers large areas of land

Glacier: A body of ice that moves down a slope

due to gravity. It forms when snow accumulates and is compacted to

form ice


lakes

Almost 69% of the earth’s freshwater is trapped in ice caps

and glaciers. But they are usually far from

where people stay and are hence inaccessible


lakes

River: • A large natural stream of fresh water flowing along a

definite course into another water body• Source may be a lake, spring or melting glacier• As the river flows downstream, precipitation,

groundwater and other smaller streams (tributaries) add to the flow

• The end of a river is its mouth where it flows into another body of water such as a lake or the ocean


lakes

The Great Lakes of North America is the largest group of freshwater lakes on earth


lakes

Lakes:• A body of water occupying a hollow in the earth’s

surface

Let’s try the question on pg 140!

Locations with water shortage

Distribution of water on earth

Ocean


lakes

Groundwater

• Most of earth’s water is in the oceans, BUT IT IS TOO SALTY TO USE OR DRINK

• Almost 69% of the earth’s freshwater is trapped in ice caps and glaciers, BUT THEY ARE USUALLY INACCESSIBLE FOR PEOPLE TO USE THEM

• LESS EASY TO ACCESS • People are increasingly

drawing from groundwater in places where there is insufficient surface fresh water

The amount of fresh water available to a country varies tremendously worldwide

Fresh water availability of a country =

Country’s total water resources (cm3) Total population

Fresh water availability

This tells you whether or not the country is experiencing water shortage

Locations with water shortageThere are different levels of fresh water availability:

Water securityWater vulnerabilityWater stressWater scarcity

Locations with water shortageWater security

When a country has adequate and sustainable fresh water for human consumption and use more than 2,500 m3 per capita per year

Locations with water shortageWater vulnerability

If fresh water availability is between 1,701 and 2,500 m3

Locations with water shortageWater stress

If fresh water availability is between 1,001 and 1,700 m3

Locations with water shortageWater scarcity

When fresh water availability falls below 1,000 m3

Checklist Recap on last lesson: Uses of water Water footprint

Locations with water shortage

Let’s zoom in and look at

Africa!

Water shortage

Due to natural factors

Many countries in Northern Africa cannot meet their current water demand because of - Low rainfall- Hot and dry climate ( higher evaporation rates reduced infiltration smaller groundwater supply)

Due to human activities

- Over diversion of water away from the sea- Large scale irrigation projects

Irrigation

projects on the

Mekong river

Water shortage (due to natural factors)Eg1. Africa

• Northern Africa is one of the driest areas in the world

• Rainfall is low and unreliable (NATURAL factor)

Eg2. Uzbekistan• Due to increasing

demand for crops, the increase in irrigation (HUMAN activity) led to decreasing supply of water

Water shortage (due to human activities)

Eg2. Uzbekistan


Since 1950s: People have diverted water from the rivers that flow into the Aral Sea to large-scale irrigation projects for crops such as rice and cotton

Eg2. Uzbekistan


By early 1980s: Aral Sea’s water supply was completely cut off and Aral Sea began to shrink drastically

Eg2. Uzbekistan


By 2006: Aral Sea had dried up to almost 10% of its original size as the Aral Sea is a closed lake and it has no outlet

Eg2. Uzbekistan


Over time: Remaining water in the sea has become salt water and thus less suitable for drinking

Eg2. Uzbekistan


Eg. UzbekistanBy the time you get married and start a family, perhaps in

2030, how do you think the Aral Sea would look like?

Why water shortage occurs

Demand factors

Rapid population growthLeads to need for increased food production & increase in household consumption this increases the demand for water.- But water supply cannot keep up with such increasing demands.

Affluent lifestylesWith more money, people start to- Consume more water-intensive meat, goods and appliances- Use more water for ornamental & leisure purposes

Supply factors

Seasonal rainfall

Water pollution

Why water shortage occurs

________ factors

Rapid population growthLeads to need for increased food production & increase in household consumption this increases the demand for water.- But water supply _____ ________________ such increasing demands.

Affluent lifestylesWith more money, people start to- Consume more _________________ meat, goods and appliances- Use more water for ______________ & ________purposes

________ factors

_______rainfall

Water _______

Ornamental purposes

Seasonal rainfall

How can Singapore avoid water shortage

Chapter 4(Textbook pg 156-170)

What do you think this quote is trying to tell us?

We never know the worth of water till the well is dry. Thomas Fuller,

Writer

Water is a scarce and precious resource in Singapore

Our population: 5.31 million peopleOur land size: 715.8 km2

Our total annual rainfall: 2357.8 mm

SG is densely

populated! (many

pple living in the same area!)

High!But we have too little land to

capture rainfall for use by Singaporeans & our

industries!

Plus, SG has no natural aquifers or lakes, and little land to collect water…

BUT, with the use of technology, Singapore has found ways to overcome our water shortage!

Today, Singapore is a world leader in sustainable water resource management. What does

sustainable mean?

Sustainable water resource management

Planning and distributing water resources in a way that they will not be depleted.

Ensuring that there will be minimal damage to the environment in the process of using or recycling water.

Water Resource Management in SG

Causes of water

shortageDemand factors• Higher

water consumption

Supply factors• Reduced

clean water supply

Managing our water resources

Reduce water consumption• 1) Making people pay for

water• 2) Public education

Increase water supply• 3) Local catchment water• 4) Import water• 5) NEWater• 6) Desalinated water

PUB conservation• 7) Protect our waterways


Reduce water demand by reducing water consumption: 1) Pricing of water

What is it? The water conservation tax is a pricing system where an additional amount of money is charged based on total water consumption.

U-Save rebate:This rebate helps to offset the utility bills for lower-income families.



Water is being priced higher when the

consumption amount is greater

• It thus encourages people to reduce their water consumption because the more water they use, the higher the tax rate.



Advantages:

• Water pricing allows people to be more mindful of their water consumption.

• It reflects the cost of producing clean water,

• thus people can appreciate the value of clean water.



Disadvantages:

• For industries that use a lot of water, water pricing increases their total cost of production.

• Water pricing may not affect those who can afford the higher price.

• Thus, they may continue to use any amount of water they want.


Reduce water demand by reducing water consumption: 2) Public education

PUB started the Water Efficiency Labelling Scheme to allow consumers to make informed choices when purchasing household products (encourages them to buy water-efficient products).Ticks indicate the water efficiency level of a product (more ticks more efficient)



In the PUB’s water-saving kit, there is a set of thimbles that can be placed on taps to allow residents to control the rate of water flow from their taps.



Advantages:

• Public education can teach many people about the importance of water in their lives.

• It has the potential to make lasting positive changes in people’s water use habits.


Reduce water demand by reducing water consumption:

Disadvantages:

• It takes time to change people’s behavior.

• Its success depends on whether people want to change their behavior. Some people may ignore the advices given.

2) Public education

Surface catchments provide ½ of

the country’s

water needs


Increase water supply 3) Local catchment water

How? Rainwater collected in rivers, streams, drains, canals and stormwater collection ponds is channeled to reservoirs where it is stored.

Local catchment (the Marina Barrage)

Marina reservoirAlexandra canal

Marina reservoir

Alexandra canal

ABC program @ Alexandra Canal

ABC program @ Alexandra Canal


Advantages:

• Local catchment takes advantage of Singapore’s high rainfall.

• Local catchment areas can also be recreational places.



Disadvantages:

• Land used for local catchment implies less land is available for other uses such as housing and industry.

• When there is little rainfall or a drought, local catchment areas are ineffective.



Increase water supply 4) Import water

How? Pipelines were built to transport water from Johor to Singapore.

SGcan be totally

self-sufficient

Agreements signed

with Johor

Importing water into Singapore

1961

20111962 2061

Launch of NEWater2003

Desalinated water2005


Advantages:

• Importing water does not require land and hence frees up land for other uses.

• It is a cheaper source of water than desalinated water/NEWater



Disadvantages:

• Imported water may not be enough to meet water demands.

• Water agreements eventually expire and there is no guarantees of future agreements



Increase water supply 5) NEWater

How does it work? • Used water may be treated to become

drinking water

• Result of clever planning and technology where fresh water can be used more than once

• Used water becomes a new source of water

PUB NEWater Treatment Process

http://www.pub.gov.sg/LongTermWaterPlans/wfall_3rdtapa.html

http://www.pub.gov.sg/LongTermWaterPlans/wfall_3rdtapa.html

Uses of NEWat

er

Industrial use

Blended with

reservoir water

Bottled drinking water


Advantages:

• NEWater is not dependent on rainfall because it is produced from used water

• Ultra-pure and of high quality, which the wafer fabrication industry in Singapore has found suitable for their use



Disadvantages:

• It is expensive to produce.

• The public may not be receptive to this new technology of obtaining water from used water.

• psychological barrier towards NEWater



Increase water supply 6) Desalinated water

What is it? • Desalination removes dissolved salts and

other minerals from water.

1. Step 1: Seawater goes through a pre-treatment process where suspended particles are removed

2. Step 2: Reverse osmosis technology is employed

3. Step 3: The desalinated water is blended with treated water before it is supplied to homes and industries

This plant can

produce 136,000

m3 of desalinated

water daily!

Every day, each

Singaporean uses on

average 155 litres of water


Advantages:

• Desalinated water is not dependent on rainfall and can be used to supplement water supply during a long dry spell.

• It is attractive since Singapore is surrounded by a limitless supply of seawater.



Disadvantages:

• It is very expensive to produce as the production is energy-intensive.

• Large amounts of chemicals and salt solutions are produced during the desalination process. If they are improperly disposed into the oceans, it may result in pollution.



Managing our water resourcesReduce water consumption• 1) Making people pay for water• 2) Public education

Increase water supply• 3) Local catchment water• 4) Import water• 5) NEWater• 6) Desalinated water

PUB conservation• 7) Protect our waterways


Conserve through protecting water resources7) PUB and Singaporeans

How? • Everyone has a part to play in

conserving water and keeping waterways clean in Singapore

• We can each help by keeping drains and canals in our catchment areas clean

• Protection of waterways is only possible when the community values water



Active, Beautiful, Clean Waters (ABC Waters) programme• Parks have been built near water

bodies for all to enjoy• Selected reservoirs and rivers have

been opened for various recreational activities and water sports such as kayaking, wakeboarding, rowing and sailing



‘Friends of Waters’

programme



ABC Waters Learning Trail


Advantages:

• Protecting waterways is a cost-effective method to ensure clean water.



Disadvantages:

• Its success depends on effective public education and cooperation of everybody.


WATER IS ESSENTIAL FOR LIVING.

There is an urgent need to protect our world’s water resources to ensure that they

do not run out and that everybody can get clean, fresh water.

All of us have a role to play in conserving and valuing our water resources while we

enjoy using it.We can share what we have learnt with

family and friends, practise good water-saving habits and keep the waterways

clean.

COMMON TEST

When? Week 8Topic? Water supply & Geographical skills

s1 ge slides - water

Education