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.

WHY ARE

FLOW RESOURCES IMPORTANT?

FIGURE 7.1 Waterfall in the Mealy Mountains in Newfoundland and Labrador

I wonder how moving water can be turned into energy?

flow resource a resource that must be used up when and where it is found or it is lost

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aquifer underground layer of rock that can hold water

FIGURE 7.2 This map shows the amounts of water available per person every year around the world by country.

0˚

Equator

60˚ N

30˚ N

0˚

30˚ S

60˚ S

60˚ N

30˚ N

0˚

30˚ S

60˚ S

30˚ W60˚ W90˚ W150˚ W 120˚ W 30˚ E 60˚ E 90˚ E 120˚ E 150˚ E

0˚30˚ W60˚ W90˚ W150˚ W 120˚ W 30˚ E 60˚ E 90˚ E 120˚ E 150˚ E

Antarctic Circle

Arctic Circle

Tropic of Cancer

Tropic of Capricorn

ATLANTIC

OCEAN

PACIFIC

OCEAN

ARCTIC OCEAN

PACIFIC

OCEAN

INDIAN

OCEAN

2000 km0

N

C07-F01-GO7SB

Crowle Art Group/SP

5th pass

Geography 7 SB

0-17-659048-X

FN

CO

Pass

Approved

Not Approved

10 000 or more

4000–9999

1700–3999

1000–1699

500–999

0– 499

no data

Available Cubic Metresper Person per Year

WATER IS A BASIC NEEDWater 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 WATERAs 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?

Freshwater Resources Worldwide

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WATER FOOTPRINTIn 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.

WE NEED FRESH WATER FOR FOODEvery 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. FIGURE 7.3 Different quantities

of water are needed to produce different foods.

water footprint the amount of fresh water used, directly and indirectly, to produce goods and services

How Much Water Does It Take?

4650litres of waterto make 1 steak

litres of waterto grow 1/2 kg of wheat

650litres of waterto make 1/2 kg of bread

650

1000litres of waterto produce 1 L of milk

2500litres of waterto grow 1 kg of rice

2500litres of waterto make 1 burger

litres of waterto create 500 ml of pop

125

= 50 litres

90litres of waterto make 750 ml of tea

litres of waterto grow 1 apple

70

litres of waterto make 750 ml of coffee

840

How much water is used to grow the food that you like to eat?

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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.

STEP 1

STEP 2

STEP 3

Use the Internet to research interesting facts for each body of water in the chart above (Figure 7.4).

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?

HOW TO CREATE A SPATIAL JOURNAL

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 4

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.

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.

CREATING

SPATIAL JOURNALS

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AIR IS A BASIC NEEDIf 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 USThe 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.

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

troposphere 0–18 kmozone layer

stratosphere 18–50 kmmesosphere 50–85 km

thermosphere 85–600 km

exosphere 600–10 000 km

troposphere the layer of atmosphere closest to Earth

FIGURE 7.5 These are the layers of atmosphere.

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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.

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?

WIND PATTERNSLook 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.

WE NEED THE SUNThe 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 EARTHThe 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?

Think of some places that are windy. Why are these places windier than others?

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