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The hydrosphere
OBJECTIVES
1. To find out about the distribution of water in the
hydrosphere
5. To describe the water cycle
2. To learn about the properties of water
6. To identify uses of water and causes of water
pollution
3. To study the characteristics of sea water and fresh
water
7. To study the effects of temperature on
condensation
4. To learn about ocean movement: waves, currents
and tides
8. To learn how to control variables in
an experiment
CONTENTS
CONCEPTS
•
•
•
•
•
•
PROCEDURES
& KEY SKILLS
• Observing and interpreting pie charts, graphs and diagrams
• Interpreting and explaining natural cycles
• Conducting an experiment to determine how variables can be controlled
ATTITUDES
•
•
•
•
The origin and distribution of water
The properties of water and its importance for all living things
Characteristics of ocean and fresh water
The water cycle
Uses and quality of water
Water pollution
Valuing water as an indispensable resource to sustain life
Developing a positive attitude towards the need for sustainable water management
Valuing individual initiatives aimed at reducing water consumption
Appreciating the significance of the water cycle and reflecting on the problems caused
by human activity
COMPETENCES
Mathematical competence: understanding results expressed as percentages
(sections 1 and 3, pp. 97 and 99); representing information in different graphs
(section 1, p. 97).
Knowledge and interaction with the physical world: interpreting and reproducing
a diagram of the water cycle (section 5, p. 101; Activity 17, p. 104); understanding
how to control variables in an experiment (Hands on, p. 103).
Social competence and citizenship: taking steps to reduce water pollution
(Activity 9, p. 102; Activity 16, p. 104; Web task, unit 9, Student’s CD).
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VALUES
Protection of the Environment
Access to water for all is a challenge for both
industrialised and developing countries. Water
pollution, increased use of irrigation in agriculture and
increasingly frequent droughts pose a threat to world
water resources. In order to avoid waste, it is important
to educate people about responsible water
consumption. Simple measures such as putting two
bottles in the lavatory cistern can help save water.
EVALUATION CRITERIA
1. Can describe the distribution of water in the
hydrosphere
6. Can describe how water is used and how
to reduce water pollution
2. Can describe the properties of water
7. Can understand the effects of temperature
on condensation
3. Can describe the characteristics of sea water
and fresh water
4. Can explain movements of ocean waters
8. Can understand how to control variables in
an experiment
5. Can explain and illustrate the water cycle
INTERNET, BOOKS AND FILMS
Web links
Oceans and seas
United States geological survey
Incola Davies
http://water.usgs.gov/
Collection of books with stunning photographs
and well-written texts which lead to a world of
discoveries and entertaining projects.
Web page with reliable, impartial information about
different aspects of water use in the United States.
It includes factual maps, photos and an interactive
section.
Films
The climate: water
U.S. geological survey
BBC Science and Nature
http://ga.water.usgs.gov/edu/watercycle.html
Very complete and detailed explanation
of the water cycle.
Books
The sea around us
Rachel Carson
This book talks about the formation
of the Earth, the centuries of uninterrupted rain
which created the oceans, giant squid fighting
with sperm whales, and the powerful tides which
shift 100 billions tons of water daily into Fundy
Bay.
Congo: the river that swallows all rivers
BBC Documentary
Find out about the River Congo region and places
that where undiscovered until the last half of the XIX
century, for example, Lake Tanganika.
The Endurance
Director: G. Butler
The explorer Ernest Shackelton and his crew started
out on an expedition that would be crucial for the
history of exploration: the first on-foot journey though
the Antarctic.
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WORKSHEET 1
THE HYDROSPHERE
NAME:
CLASS:
DATE:
1 Complete the text about water to find the crossword answers. Find the hidden property of water
in the crossword.
8
Water in solid form is called, 1.
.
When water freezes it 6.
unlike other substances.
3
1
2
,
4
It is made up of one 2.
6
of hydrogen and two of 7.
5
.
7
Water molecules are attracted to other molecules.
This is called 3.
. Water
moderates the Earth’s climate by absorbing
4.
. It dissolves rock components
because it is a powerful 5.
. Our
planet looks blue from space because of all the water
in the 8.
The hidden property of water is
2
.
Complete the sentences with compound nouns from the box.
sea level
rock erosion
1.
water courses
water molecules
sea water
river valleys
are attracted to each other and to other
substances.
2.
contains dissolved gases and salts.
3. Tides are the periodic rise and fall of the
4. One of the results of wave action is
5. Streams and torrents are
6.
.
.
fed by rain.
are also created by the action of water as it erodes
rocky banks.
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WORKSHEET 2
THE HYDROSPHERE
NAME:
1
CLASS:
Match the questions and answers.
1. Where do glaciers originate?
2. What are wetlands?
3. How much of the water on Earth is fresh water?
4. What happens when water freezes?
5. What does water leave when it evaporates?
6. What does the temperature of sea water vary with?
a. Water located beneath the surface
of the ground
b. Areas of marshlands and swamps.
c. Mineral salt deposits.
d. On the surface of water.
e. It dilates.
f. Like rivers through the sea.
7. Where do waves occur?
g. On mountain tops.
8. What do ocean currents move like?
h. In lakes.
9. What is groundwater?
i. 3%.
10. Where is most surface fresh water located?
2
DATE:
j. Depth.
Put the words in order and write correct sentences.
1. Earth both and salt fresh water be found can on.
Both
2. Water covers of the but only is planet 68.7 % fresh water 3%
Water
3. in the atmosphere and in living things water 0.9 % of fresh is
0.9 %
4. 2 % surface water is human fresh consumption for fit of
2%
5. beneath groundwater Earth is fresh water located the surface of the
Groundwater
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WORKSHEET 3
THE HYDROSPHERE
NAME:
1
CLASS:
DATE:
Write these words associated with the processes of the water cycle in the correct columns.
rain
clouds
hail
groundwater
water vapour
from the leaves and stems of plants
from the hydrosphere to the atmosphere
rivers and streams
porous ground
snow
dew
The water cycle
Evaporation
Evapotranspiration
Condensation
Precipitation
Surface
run off
Infiltration
rain
2
3
Read the descriptions and identify the stages of the water cycle. Then put them in order.
a.
: The leaves and stems of plants release water into the atmosphere.
b.
: A lot of water also filters into the ground, especially in places where the ground
is porous.
c.
: Water passes from the hydrosphere to the atmosphere as it changes to a gas.
d.
: The water held in the clouds falls to the ground in the form of rain, snow or hail.
e.
: Clouds and dew are formed when water vapour changes to liquid.
f.
: Water on the surface of the Earth moves across the land and into rivers
and streams.
Answer the questions in pairs.
1. List different forms in which water can be found.
Lakes,
2. List four ways of saving water.
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WORKSHEET 4
THE HYDROSPHERE
NAME:
1
CLASS:
DATE:
Work in pairs. Take turns to read and classify the sentences. Write the numbers in the boxes.
Fresh water
Salt water
Properties of water
Uses of water
1
1. It is a powerful solvent which can dissolve many components of rock.
2. It is used in many industrial processes.
3. About 0.9% of it is found in the atmosphere and in living things.
4. It is used for human and animal consumption.
5. It contains dissolved salts, mainly in the form of chlorides
and sulphates.
6. At room temperature, it flows because its molecules move freely.
7. Groundwater accounts for 30.9 % of it.
8. Oil refineries consume enormous amounts of it.
9. It is poisonous if you drink too much, and can kill you within days.
10. It can also exist as a solid and a gas.
11. Only 0.3 % of it is found on the surface of the Earth.
12. The largest body of it is the Pacific Ocean.
2
Draw a picture to illustrate one of the above sentences.
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WORKSHEET 5
THE HYDROSPHERE
NAME:
CLASS:
DATE:
Tides
A tide is the regular rise and fall of the sea caused by the
gravitational attraction of the Moon and the Sun. Tides go
through the following stages: the water rises for several
hours, reaches its highest level and stops at high tide.
It then does the opposite, falling for several hours and
finally stopping at low tide. Then the process starts all
over again.
Around new and full moon, when the Sun, Moon and
Earth form a line (a condition known as syzygy), the tidal
pull due to the Sun reinforces the tidal pull of the Moon.
As a result, high tides are higher than average and low
tides are lower than average. This is called the spring
tide, or just ‘springs’. The name is not derived from the
season of spring, but from the verb meaning ‘to jump’.
When the Moon is in the first quarter or third quarter, the Sun and Moon are separated by 90°
(as seen from the Earth), and the Sun’s pull partially cancels out the pull of the Moon. As a result,
the range of high tide and low tide is less extreme. This is called the neap tide, or ‘neaps’. There is
an interval of about seven days between springs and neaps.
1
Complete each sentence with the correct information.
1. Tides are caused by
2. First, the water rises for several hours and stops at
3. When it reaches high tide, it starts to
, finally stopping at
4. During spring tides, the gravitational attraction of the Sun
5. During neap tides, the gravitational attraction of the Sun
2
Write a definition for the word syzygy.
3
Explain the terms ‘spring tide’ and ‘neap tide’.
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TEST 9
THE HYDROSPHERE
NAME:
1
CLASS:
DATE:
Circle the correct answer.
1. The largest amount of water on Earth is found (a) in the ground (b) at the Poles (c) in the oceans.
2. Only (a) 11 % (b) 2 % (c) 0·9 % of surface fresh water is found in rivers.
3. In swamps, the ground is (a) frozen all year long (b) inundated all year (c) inundated during the
summer months.
4. Water (a) absorbs heat in summer and emits heat in winter (b) absorbs heat all year round (c) absorbs
heat in winter and emits heat in summer.
5. When water freezes (a) its mass increases (b) its weight increases (c) its volume increases.
6. Ocean currents are produced by wind, differences in temperature and (a) erosion (b) differences
in salinity (c) the gravitational attraction of the Moon.
7. During evaporation, water passes from (a) the atmosphere to the hydrosphere (b) the hydrosphere
to the atmosphere (c) the surface of the Earth to under the ground.
8. When water condenses it forms clouds and (a) dew (b) rain (c) hail.
9. Sewage originates mainly in (a) towns and cities (b) the countryside (c) industrial areas.
10. In an experiment, when the variables for the participating elements are the same, we say that they are
(a) dependent (b) independent (c) controlled.
2
Read the text and answer the questions.
A precious resource
Water is a finite resource which cannot be created or synthesized. Your body loses 1.5 to 2 litres
of water through sweat, urine and respiration. You need to drink at least an equivalent amount of
fluids to replace it for the correct maintenance of the body’s systems.
If there are six thousand million people on Earth, twelve million cubic metres of fresh water are
needed every day just to provide enough drinking water for everyone! So, we should all try to reduce
water consumption by adopting simple everyday habits. For example, take showers instead of
baths, turn off the tap when brushing your teeth, fill dishwashers and washing machines before
using them. You can install water-saving devices in the shower head and lavatory cistern. If water
in your town was suddenly rationed, you would be amazed at how many things you can do with
a small amounts of it!
1. Why do we need to drink water?
2. How much water is needed on Earth each day?
3. Write three ways of saving domestic water.
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