WHY ARE
FLOW RESOURCES
IMPORTANT?
As you read in Chapter 5, flow resources include water, air, and sunlight.
Running water (Figure 7.1), wind, and sunlight are called flow resources
because they flow or move. Flow resources are neither renewable nor
non-renewable.
Flow resources are extremely important to us and to all living things.
Without them, there would be no life on Earth. We drink water. We need air
to breathe. Plants use sunlight to grow and support other life. As well, these
resources supply us with energy when they are “on the move.” For example,
we use the energy created by water when it flows as rivers, ocean currents,
and tides. We use the energy created by air when it moves as wind, and we
use the Sun’s energy as it arrives through the atmosphere as sunlight. We
must use the energy created by flow resources when and where it occurs.
Because flow resources are so important, we need to understand more
about what they are and how we can use them wisely and sustainably.
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UNIT 2: Our World’s Natural Resources: Use and Sustainability
flow resource a resource
that must be used up when
and where it is found or it
is lost
FIGURE 7.1 Waterfall in the
Mealy Mountains in Newfoundland
and Labrador
I wonder how moving
water can be turned
into energy?
NEL
WATER IS A BASIC NEED
Water is our most precious natural resource. It is a basic need for all living
organisms. As well, different water bodies, from oceans and rivers to
wetlands and lakes, are unique ecosystems for many plants and animals.
WHERE WE FIND FRESH WATER
As you read in Chapter 4, about 97 percent of the water on Earth is salt
water and about 3 percent is fresh water. However, we only have access to
about 1 percent of Earth’s fresh water. We need fresh water to survive. Some
countries have more fresh water than others (Figure 7.2).
A small percentage of fresh water is found in rivers and lakes. Most fresh
water, however, is groundwater, which is water under Earth’s surface. It is
stored underground in natural rock formations called aquifers. An aquifer
is an underground layer of rock, such as sandstone, that can hold water in
the spaces between the grains of sediment. Water from rain or melted snow
drains into the ground, moving downward until it reaches, and fills, the
aquifer.
The aquifer acts as a reservoir. Aquifers can supply water to wells or
springs. They range in size from several square kilometres to thousands of
square kilometres. They are important for millions of farmers worldwide
who use them to irrigate their fields and water their livestock. As well, they
are an important source of drinking water for over 2.5 billion people.
How do you
think the location of
water has influenced
where people live?
aquifer underground layer of
rock that can hold water
Freshwater Resources Worldwide
150˚ W 120˚ W 90˚ W 60˚ W 30˚ W 0˚ 30˚ E 60˚ E
ARCTIC OCEAN
90˚ E 120˚ E 150˚ E
Arctic Circle
60˚N
60˚N
30˚ N
0˚
Tropic of Cancer
ATLANTIC
PACIFIC
OCEAN
OCEAN
30˚N
PACIFIC
Equator
0˚
OCEAN
Available Cubic Metres
per Person per Year
INDIAN
OCEAN
Tropic of Capricorn
30˚10
S 000 or more
30˚ S
N
4000–9999
1700–3999
0
1000–1699
500–999
0–499
60˚ S
2000 km
60˚S
Antarctic Circle
no data
150˚ W 120˚ W 90˚ W 60˚ W 30˚ W
0˚
30˚ E 60˚ E
90˚ E 120˚ E 150˚ E
FIGURE 7.2 This map shows the amounts of water available per person
every year around the world by country.
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197
WATER FOOTPRINT
In Chapter 5, you learned about ecological footprints. Ecological footprints are a
calculation of the natural resources we use. The term water footprint describes
the amount of fresh water used by individuals, communities, or businesses. It is
useful to compare the water footprints of different countries. A country’s water
footprint tells us how much fresh water people in that country consume per
capita, or per person. It includes the amount of fresh water used to produce the
goods and services consumed by the people in a country.
Canada’s water footprint is 2333 m3/year. This is almost double the global
average of 1385 m3/year. The water footprint of Belize, in Central America, is
about one and a half times the global average. Why does the footprint differ
so much from country to country? People in each country use very different
amounts of water. This is because not every country has the same amount
of water available for use. Also, the water footprint depends on the climate
conditions in each country and the ways in which water is used to make
goods. It also depends on what products the people consume.
water footprint the amount
of fresh water used, directly
and indirectly, to produce
goods and services
WE NEED FRESH WATER FOR FOOD
Every day, people use fresh water for many reasons. About 10 percent of
the water we use is for daily tasks such as drinking, cooking, and washing.
Around 20 percent is used by industries to produce electricity and to
manufacture and transport products. Farmers use the most water—about
70 percent of water is used for agriculture and irrigation.
It’s not just plants that need water. Raising animals for meat uses a
great deal of water—more than we use for growing vegetables. Figure 7.3
demonstrates how much water it takes to produce different kinds of food.
How much water is
used to grow the food
that you like to eat?
FIGURE 7.3 Different quantities
of water are needed to produce
different foods.
How Much Water Does It Take?
70
litres of water
to grow 1 apple
90
125
650
650
litres of water
to make 750 ml of tea
litres of water
to create 500 ml of pop
litres of water
to grow 1/2 kg of wheat
litres of water
to make 1/2 kg of bread
840
1000
2500
2500
4650
litres of water
to make 750 ml of coffee
litres of water
to produce 1 L of milk
litres of water
to grow 1 kg of rice
litres of water
to make 1 burger
litres of water
to make 1 steak
= 50 litres
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UNIT 2: Our World’s Natural Resources: Use and Sustainability
NEL
CREATING
SPATIAL JOURNALS
Spatial journals combine different kinds of information with a map in order
to tell a story. Spatial journals tie information to specific locations. You can
display interesting facts, photos, and details such as specific coordinates
all in one place. The map on page 132 is an example of a spatial journal.
You can make a spatial journal using online mapping technologies such
as Google Earth. In the steps below, you will use Google Earth to create a
spatial journal.
Use the chart below to make a spatial journal comparing different
bodies of water.
Body of Water
Where?
What?
Dead Sea
31.52°N
35.48°E
lowest body of water in the world
mouth of the Amazon River
0.22°N
50.60°W
largest river by water flow in the world
Lake Gatun
9.20°N
79.88°W
part of the Panama Canal
Lake Titicaca
15.79°S
69.38°W
highest navigable lake in the world
FIGURE 7.4 This chart contains information you can use to make a spatial journal.
HOW TO CREATE A SPATIAL JOURNAL
Use the Internet to research interesting facts for
each body of water in the chart above (Figure 7.4).
STEP 1
STEP 2
You can now add information to your map by
using the Add Placemark icon. Add a label
(for example, “Dead Sea”) in the dialogue box.
Add an interesting fact to the dialogue box (for
example, elevation = -415 m). Save the dialogue
box by clicking OK.
STEP 3
STEP 4
NEL
Start Google Earth. Select one of the bodies of
water in Figure 7.4 and enter the coordinates, as
they are written in the table, into the search box.
Double-click on the map so that the map centres
on that location. What do you see?
You will now see the dialogue box you created in
the Table of Contents on the left. When you click
on it, you will notice a note pops up directly in the
correct location on the map. Repeat Steps 2 and 3
for the other entries on the chart.
CHAPTER 7: Flow Resources
199
AIR IS A BASIC NEED
troposphere the layer of
atmosphere closest to Earth
If you look at Figure 7.5, you can see that five layers of atmosphere surround
Earth. They are called the exosphere, thermosphere, mesosphere, stratosphere,
and troposphere. Each has a different range of temperatures. The layers of
atmosphere are made up of gases: 78 percent nitrogen, 21 percent oxygen, and
the remainder made up of other gases. They are held in place by Earth’s gravity.
The layer of atmosphere closest to Earth is the troposphere. It makes
up 75 percent of the atmosphere, even though it only extends from Earth’s
surface to between 6 to 18 km above Earth. Weather takes place in this thin
layer, as does most of life on Earth.
THE ATMOSPHERE PROTECTS US
stratosphere the second
layer of atmosphere above
Earth
ozone layer a region of ozone
gases high in the atmosphere
that protects us from
ultraviolet light
FIGURE 7.5 These are the layers of
atmosphere.
The gases in the atmosphere help to protect Earth. Without the atmosphere,
it would get so cold at night that we would freeze. The heat and light from
the Sun would be so intense it would burn us. Also, ultraviolet rays from the
Sun can harm trees, plants, and animals. They can cause skin cancer and
eye problems in people. In the stratosphere is a layer of ozone gas. The
ozone layer absorbs the harmful ultraviolet rays from the Sun.
We also need air to breathe. All living organisms require air. Animals
breathe in oxygen and breathe out carbon dioxide (CO2). Plants use nitrogen
and CO2 to produce their own food. Even microscopic bacteria use gases
found in the atmosphere to survive.
000 km
re 600–10
exosphe
00 km
phere 85–6
thermos
m
ere 50–85 k
mesosph
km
here 18–50
stratosp
yer
ozone la
ere 0–18 km
troposph
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UNIT 2: Our World’s Natural Resources: Use and Sustainability
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WIND PATTERNS
Look back to Figure 2.14 in Chapter 2, which shows the wind patterns
around the world. Some parts of the planet are more windy than others.
Areas where the high- and low-pressure areas are closer to each other are
windier. Coastal areas are windy because the land and the sea heat up at
different rates, causing differences in air pressure.
Think of some
places that are windy.
Why are these places
windier than others?
WE NEED THE SUN
The Sun is a giant sphere of gas with huge quantities of hydrogen under
pressure at its extremely hot core. The pressure and the hot temperatures
cause the hydrogen to convert to helium. This reaction releases an
enormous amount of energy. Some of this energy reaches Earth.
THE SUN SUPPORTS LIFE ON EARTH
The Sun provides us with heat and energy. Without the Sun, nothing could
live on Earth. It supplies light and heat, both of which can be transformed
into energy. Plants use the Sun’s energy to make their food. Through
photosynthesis, plants change water and CO2 into a kind of sugar,
which they use to grow. Plants also produce oxygen. Most animals
need oxygen, so they depend
on plants (Figure 7.6).
In this way, all living things
are linked together. At
each stage, some energy
is being used and some is
being stored.
The Sun’s energy passes
through the atmosphere and
heats Earth. In Chapter 2,
you read about how some
gases in the atmosphere
absorb energy from the Sun.
This greenhouse effect is an
important natural process
that keeps Earth warm
enough to support life.
FIGURE 7.6 Some mammals are
carnivores and eat meat. Herbivores,
such as this elk, only eat plants.
How do I rely on the Sun?
CHECK-IN
1. COMMUNICATE Create a poster that clearly shows
the differences between flow resources and
renewable resources.
2. FORMULATE QUESTIONS With a partner, formulate
some questions that would help you find out how
people use wind and sunlight. Create an annotated
illustration to respond to one of your questions.
NEL
3. SPATIAL SIGNIFICANCE Using Figure 7.2, which is the
Freshwater Resources Worldwide map, identify
one country in each category. For each country,
name and locate the capital city and find out
the population of the country. What additional
geographic factors would tell you more about the
availability of water in each place?
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201