Water cycle and
our water needs
Activity 1
Desalination provides
an extra source of
water that doesn’t rely
on rain.
Summary
Using the diagrams provided, students identify
features of the water cycle and examine
changes in rainfall and temperature in Australia.
They then use this knowledge to think about
how we manage the natural water cycle to meet
our water needs.
Contents
1. Curriculum links
2. The water cycle
Resources
3. Changing patterns of rainfall
The activities are designed to work in
conjunction with Sydney Water’s desalination
plant virtual tour.
4. Our water needs
Curriculum links
Science
Year 7 – Science understanding
Earth and space sciences
Water is an important resource that cycles
through the environment (ACSSU222)
•
considering the water cycle in terms of
changes of state of water
•
investigating factors that influence the water
cycle in nature
•
exploring how human management of water
impacts on the water cycle.
ScOT catalogue terms: Water cycle
Geography
Year 7 – Environmental characteristics
Weather and water
“In Year 7 the focus is on weather and
water, including topics such as weather
and rainfall, the hydrologic cycle,
weather hazards (cyclones, storms,
droughts and floods), world water usage
and distribution, and water resource
management. This focus links with Year
7 science.”
Page 27
http://www.acara.edu.au/verve/_resources/Shap
e_of_the_Australian_Curriculum_Geography.pdf
Because of climate
change and population
growth we no longer
rely on water from
dams alone.
Water cycle and our
water needs
The water cycle
1. Based on your knowledge of the water cycle, label this
diagram using the text below.
Cloud formation
Groundwater
Surface runoff
Precipitation
Evaporation
Condensing water vapour
Oceans contribute
about 80% of total
water vapour
2. How do we manage the natural water cycle to meet our needs?
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3. What is the source of most of our drinking water?
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4. What are some of the benefits and problems that are associated with this water source?
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5. Name any ways of sourcing water that don’t rely on rainfall. Where does this water comes from?
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Changing patterns of rainfall
Australia is a country that has a wide variety of rainfall patterns. Examine the map below and answer the
following questions.
Map 1: Average annual rainfall between 1961 and 1990
Source: http://reg.bom.gov.au/cgi-bin/climate/change/averagemaps.cgi?map=rain&season=0112
Using Map 1 as a guide:
6. Name two Australian cities or towns that received an average of 2400 mm of rainfall or more a year
between 1961 and 1990. Describe their location (for example, inland or coastal) and type of natural
environment (for example: desert, rainforest, grassland, mountains, coastal).
a. ______________________________________________________________________________
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b. ______________________________________________________________________________
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7. Name two Australian cities or towns that received an average of 400 mm of rainfall or less a year
between 1961 and 1990. Describe their location (for example, inland or coastal) and type of natural
environment (for example: desert, rainforest, grassland, mountains, coastal).
a. ______________________________________________________________________________
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b. ______________________________________________________________________________
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The map below shows trends in total annual rainfall – changes observed over ten years from 1970 to
2010. The shading indicates how many mm more, or less, an area has received for each decade.
Map 2: Rainfall trends from 1970 to 2010
Source: http://reg.bom.gov.au/cgi-bin/climate/change/trendmaps.cgi?map=rain&area=aus&season=0112&period=1970
8. Mark Map 2 with the four cities or towns you identified in Map 1. Also identify where you live (if this
was already one of your four cities or towns, choose another location).
Using Map 2 as a guide:
9. Fill out the following chart:
Rainfall trends
City/town
Has it become drier
or wetter over the
past 40 years?
If this trend continues, how might
this affect the population?
10. When an area has become drier over a period of time, what are some of the ways people have tried
to deal with the problem?
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Our water needs
From 2001 to 2008, much of Australia was going through a drought.
This is a graph that shows a comparison between the water levels in the Sydney dam network and the
population of the area at the time.
Figure 1: Dam level and population growth
Using Figure 1 as a guide:
11. Explain what happened to water levels in Sydney’s dam network over the time shown in the graph.
How much did the levels change?
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12. Explain what happened to the population in the Sydney area over the time shown in the graph. How
much did it change?
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13. As the graph shows, when the dam levels started to drop, water was transferred from Tallowah Dam
into Sydney’s dam network. Why do you think this happened?
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14. The graph was created to explain the decision to build Sydney’s desalination plant. Looking at the
information presented in the graph, how does the graph explain the decision?
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