G EO

GEOGRAPHY
Exp r e ss / N o r m al ( Acad e m i c)
L o w e r Se co n d ar y G e o g r ap h y Co u r s e b o o k ( B o o k O n e )

Coursebook Express / Normal (Academic)

GR A
PHY
Lower Secondary Geography Coursebook (Book One)
Express / Normal (Academic)

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 Lower Secondary Geography Coursebook (Book One)
Express / Normal (Academic)

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 © 2021 Curriculum Planning & Development Division
Ministry of Education, Singapore
51 Grange Road
Singapore 249564

Published by Marshall Cavendish Education

Times Centre, 1 New Industrial Road, Singapore 536196
Customer Service Hotline: (65) 6213 9688
E-mail: cs@mceducation.com
Website: www.mceducation.com

Marshall Cavendish is a registered trademark of Times Publishing Limited.

First published 2021

All rights reserved. No part of this publication may be reproduced, stored in

a retrieval system or transmitted, in any form or by any means, electronic,
mechanical, photocopying, recording or otherwise, without the prior
permission of the copyright owner. Any requests for permission should be
addressed to the Ministry of Education, Singapore.

ISBN 978-981-4643-52-8

Printed in Singapore

SecGeoEX_NA_Course1_Front Matter.indd 2 6/7/20 10:39 AM

 PREFACE
“We are all explorers. Even as tiny children we search out the limits of our world. A few years on,
our imagination stretches further fingers batting at a giddy plastic globe representing perhaps iii
the most ambitious idea possible, the world. Geography is a fundamental fascination. It is also a
core component of a good education.”

– What is Geography?, by Alastair Bonnett, Geography academic.

Have you ever wanted to explore and understand the environment around you? How forests develop,
how water is generated by the earth and how we make use of these resources? The Lower Secondary
Geography Coursebook is a resource that will assist you with this journey as you explore the wonder of
two main resources on Earth, namely, our water supply, tropical rainforests and mangroves. You will be
equipped with new lenses to view your world, as you are trained to ask the questions of “What is where?”
and “Why there?”. You will investigate the challenges that these resources face in being sustainable –
to provide for human beings in the long run. It is also then you will ultimately discover your motivation –
“Why you should care” – about this living, breathing, wondrous world that surrounds you.

We would like to thank the following academics for their valuable contributions to the development of
this coursebook.

Dr Daniel Friess
Dr Kalyani Chatterjea
Dr Kim Irvine
Dr Lin Weiqiang
Dr Pow Choon Piew
Dr Sorain Ramchunder
Dr Tricia Seow

We would also like to extend our gratitude and appreciation to the following schools and institutions for
their contribution in the development of this coursebook.

Broadrick Secondary School

Bukit Merah Secondary School
Catholic High School
Evergreen Secondary School
Meridian Secondary School
New Town Secondary School
North Vista Secondary School
Pasir Ris Crest Secondary School
Queenstown Secondary School
Unity Secondary School
Yuan Ching Secondary School
Zhenghua Secondary School
Department of Geography, Faculty of Arts and Social Sciences, National University of Singapore
Humanities & Social Studies Education Academic Group, National Institute of Education,
Nanyang Technological University

SecGeoEX_NA_Course1_Front Matter.indd 3 6/7/20 10:39 AM

 FEATURES CHAPTER

iv 2

INTRODUCTION
This coursebook takes you
on a journey of experience.

TO GEOGRAPHY
These key features help you
to orientate the content that has Each chapter
begins with the
Learning
been written for you. Outcomes
In this chapter, we will learn to:

learning outcomes.
• describe how geographers
study the world; and
• describe physical and built
environments.

A photograph showing built

environment in Singapore – Pang
Sua Pond in Bukit Panjang

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HOW DO TROPICAL FORESTS

WHAT IS THE ATMOSPHERE? CONTRIBUTE TO CARBON STORAGE?
The atmosphere is the layer of gases and tiny particles that
Rainforest and mangrove plants contribute to carbon storage when they absorb carbon
surrounds the earth. Some examples of gases that make up
dioxide from the atmosphere during photosynthesis. This helps to balance the amount of
the atmosphere are nitrogen, oxygen and carbon dioxide.
carbon dioxide being added to the atmosphere through natural processes like respiration
8 It is further divided five layers troposphere, 129
stratosphere, mesosphere, thermosphere and exosphere. and decomposition.

The condition of the atmosphere at a given time Carbon dioxide in the

and place is known as weather, which includes atmosphere is absorbed
temperature, humidity, rainfall and wind.
Water
through photosynthesis.

74 75

Geo-Fact
The atmosphere has many layers.
• troposphere: The lowest layer of Earth’s atmosphere. Most clouds,
precipitation and other weather elements occur within this layer.
What Relationship Does Water Have How Can Water Be • stratosphere: The layer of Earth’s atmosphere above the troposphere. Dead leaves and branches that
Within the stratosphere, temperature usually remains constant. The absorbed carbon dioxide fall to the ground add carbon
With the Environment and People? Managed Sustainably? • mesosphere: The layer of Earth’s atmosphere directly above the
is stored in solid form in to the soil.
stratosphere and below the thermosphere. Throughout the mesosphere,
the plants — in their leaves,
temperature decreases with height.
branches, stems and roots.
• thermosphere: The layer of Earth’s atmosphere above the mesosphere,
extending to the uttermost fringe of the atmosphere. In this layer,
temperature increases sharply in the lower thermosphere, then drops off
and holds steadily with increasing height.
How Do Variations In How Does Water How Do People How Do Human • Improve water quality • exosphere: The outermost layer of Earth’s atmosphere.
• Reduce water consumption
Precipitation Affect The Support River Use Water? Actions Lead to Water • Improve water technologies
Availability Of Water? Ecosystems? Pollution and Its • Import water
Associated Impact? km
0

The roots of the plants also produce soil carbon.

00
90

• Floods • Domestic
–1

• Droughts • Recreation km
0

0
70
70

• Agriculture
0–
>

• Industry Figure 6.2 A diagram showing how trees contribute to carbon storage
RE

8
E
P HE

Among the different types of natural vegetation, mangroves are one of the
ER

km most effective at storing carbon. It is estimated that on average, they store about
PH

80
S

0–
EXO

0 0 kilogrammes of carbon per square kilometre every year. This is significantly

OS

m higher than tropical rainforests, which store about 20 kilogrammes of carbon

RM

0k
5

–5
E

per square kilometre every year.

ER
THE

10
PH

km
–30
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As the soil in mangroves

E
OS

20 is waterlogged and poor in

HE

Questions for understanding

MES

0 km oxygen, there are few bacteria

SP

0–1
R
YE
TO

E available to break down the If there were no tropical forests to store carbon, what do you think
LA

carbon stored there. This

S T RA

would happen to the earth What makes you say so

POSPHE
OZONE

is why mangroves are so

Figure 1.2 A diagram showing layers of the atmosphere effective at storing carbon.
TRO

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Chapter overview Geo-fact Questions for

Introduces a summary of Explores interesting facts understanding
the key terms and concepts related to the concepts Pauses to check your
that you will learn in the and content of the chapter mastery of the content
chapter

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 ONE
water vapour
What Are the
Physical States 55
v
of Water?
water vapour

condensing

evaporating

Each chapter is divided into sub-sections

Water exists in solid, liquid and gaseous states.

SOLID liquid

that are indicated by guiding questions.

When it is hot, some of us may want a glass of iced water. The ice
that we see is water in its solid state. Under cold temperatures, water
water droplets freeze into ice. We can also see ice in snow, glaciers
and hail.
melting

Figure 3.1 A photograph showing Figure 3.2 A photograph showing

ice

solid
freezing

ONE TWO THREE

cars covered in snow in hailstones collected after
Bucharest, Romania a hailstorm

LIQUID Figure 3.3 A diagram showing

how water changes its
When we turn on the tap to get water, we see water in its liquid states through melting,
state. Water in its liquid state appears as water droplets. We can freezing, evaporating
also see water droplets when it rains, and in rivers or reservoirs. and condensing

GAS
When water boils, we see a cloud of mist that is made up of water droplets. What we cannot see is
steam, which is made up of water vapour. Water vapour is water in its gaseous state. Since evaporation
occurs all the time and at any temperature, water vapour is always in the air around us.

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Questions for reflection

60 m
WHAT ARE GLACIERS?
CHAPTER GLOSSARY
In what ways does the
physical environment
Glaciers are large masses of ice that rest on land To learn more about
affect humans? How do
or float in the sea. They are found in places where this chapter, check
humans affect the physical out this lesson on the
it snows throughout the year so that enough snow
environment? Singapore Student Features that plants have developed through evolution,
accumulates and hardens into ice. Glaciers move
How would you describe
slowly because they are very heavy. Learning Space.
go.gov.sg/lsg004
Adaptations which make them suited to their environment and help them
to survive
120
humans’ relationship with
the physical environment? 50 m
Figure 3.4 A map showing major glaciers around the world Plant roots that for at least part of the day are exposed to the air,
Aerial roots allowing the plant to breathe
Types of Water Stores
A R C T I C O C E A N
Greenland
in the World Annual rainfall The total amount of rainfall a place receives in a given year
Glacier

Ural Mountains
Saint Elias
Mountains Vatnajökull
96.5% Broad leaves Plant leaves that have a large surface area
Oceans
Alps Mountains 40 m
Caucasus Mountains
Glacier
Large roots that grow above the ground surface to provide
Buttress roots support to tall trees
Himalayan Mountains
A T L A N T I C
The thick and near-continuous layer formed by the tops of
O C E A N
Canopy layer rainforest trees of approximately the same height
P A C I F I C O C E A N
The average weather conditions of a place over a long period of
Climate
Mount Kilimanjaro
I N D I A N
30 m time, usually over 30 years
shorea
acuminata tree O C E A N Coast The boundary between the land and the sea
30–40 years to oil palm Andes
Mountains N
grow to maturity. 2–3 years to grow to
1.03% Thick and conical aerial roots that grow vertically upwards from
Up to 60 m tall. maturity. Up to 20 m tall. 1.7% Cone roots
Others beneath the soil surface
Glaciated area Southern Alps Mountains Glaciers
(swamps,
marshes,
0.76%
20 m S O U T H E R N O C E A N
Groundwater
atmosphere) Diversity The range of different things

0.002%
Antarctica 0.007% Rivers Drip tips The narrow, downward-pointing ends of leaves that allow
custard apple tree Lakes rainwater to flow off easily
5 years to grow to
maturity. Up to 10 m tall. 0.001% The layer formed by the tops of the tallest trees in the tropical
Soil moisture Emergent layer rainforest that rise above the canopy

10 m An imaginary line on the Earth’s surface that is of equal distance

Figure 3.6 A pie chart
showing the Equator from the North and South Poles it is defined as latitude 0 and
proportion of water divides the Earth into the northern and southern hemispheres
found in different
water stores
Evergreen Producing green leaves throughout the year

Figure 3.5 A photograph showing the Perito Moreno Glacier, Argentina Forest structure The vertical or horizontal arrangement of plants in a forest
0m

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ues ions or refle ion QR code Chapter glossary

Considers possible Links to a Singapore Refreshes your memory
implications of your Student Learning Space of the meaning of key
lifestyle on the world, and (SLS) lesson related to the terms so as to clarify your
possible actions you can chapter to extend your understanding of the
take to make a difference learning content

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 CONTENTS
CHAPTER 1
vi INTRODUCTION TO GEOGRAPHY 2
ONE What Is Physical Geography? 6
TWO What Is Human Geography? 11
THREE What Are Geographical Concepts? 13
FOUR What Is Geographical Inquiry? 21
CHAPTER GLOSSARY 24

CHAPTER 2
HOW CAN WE SUSTAINABLY
MANAGE NATURAL RESOURCES? 26
ONE What Is a Resource? 30
TWO What Is a Natural Resource? 34
THREE How Do People’s Views Affect
the Use of Natural Resources? 38
FOUR What Does Sustainable Use
of Natural Resources Mean? 40
FIVE How Can We Use Natural
Resources Sustainably? 42
CHAPTER GLOSSARY 48

CHAPTER 3
WATER AND ITS SPATIAL DISTRIBUTION 50
ONE What Are the Physical States
of Water? 55
TWO Where Is Water Found? 56
THREE What Is the Hydrological Cycle? 62
FOUR What Is Water Budget? 64
CHAPTER GLOSSARY 70

CHAPTER 4
SUSTAINABLE MANAGEMENT OF WATER 72
ONE How Do Variations in Precipitation
Affect the Availability of Water? 76
TWO How Does Water Support River
Ecosystems? 79
THREE How Do People Use Water? 80
FOUR How Do Human Actions Lead
to Water Pollution and Its
Associated Impact? 84
FIVE How Can Water Be Managed
Sustainably? 86
CHAPTER GLOSSARY 95

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 CHAPTER 5
SPATIAL DISTRIBUTION OF TROPICAL vii
RAINFORESTS 96
ONE What Is Natural Vegetation? 102
TWO What Is the Tropical Climate? 104
THREE What Are Tropical Rainforests
and Where Are They Found? 105
FOUR What Are the Characteristics of
Tropical Rainforests? 106
FIVE How Have Plants in Tropical
Rainforests Adapted to
Their Environment? 110
SIX What Are Mangroves and
Where Are They Found? 112
SEVEN What Are the Characteristics of
Mangroves? 114
EIGHT How Have Plants in Mangroves
Adapted to Their Environment? 116
CHAPTER GLOSSARY 120

CHAPTER 6
SUSTAINABLE MANAGEMENT OF TROPICAL
RAINFORESTS AND MANGROVES 124
ONE What Are the Environmental
Functions of Tropical Forests? 128
TWO How Are Tropical Forests Used
by People? 134
THREE What Are the Consequences of
Extracting Resources From
Tropical Forests? 141
FOUR How Can Tropical Forests Be
Managed Sustainably? 146
CHAPTER GLOSSARY 155

A R C T I C O C E A N
INDEX 156

158
Lake Baikal Lake Superior
Danu
be River Caspian
Sea
Lake
Balkhash
Great
Lakes
WORLD POLITICAL MAP
Mi River

Ri
llow ver
ssis

Ye
sippi

A T L A N T I C
Me

iver
Ga ze R
Yangt
kon

Riv nges

160
er
Nile River

O C E A N
gR

WORLD RELIEF MAP

iv e

P A C I F I C O C E A N
Lake Victoria
Amazon River

I N D I A N

ACKNOWLEDGMENTS 162
O C E A N

S O U T H E R N O C E A N

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 CHAPTER

INTROD
Learning
Outcomes
In this chapter, we will learn to:
TO GEO
• describe how geographers
study the world; and
• describe physical and built
environments.

A photograph showing the built

environment in Singapore –
Pang Sua Pond in Bukit Panjang

SecGeoEX_NA_Course1_Ch1_3rdpf.indd 2 06/07/20 6:06 PM

ODUCTION
EOGRAPHY

To learn more about

each chapter, check
out this overview of
all the Secondary 1
lessons available on
the Singapore Student go.gov.sg/lsg001
Learning Space.

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 Introduction to Geography
The word “geography” is made up of two parts: “geo-”, which refers to the
earth, and “-graphy”, which refers to description. Geography thus refers
4 to the study of the earth, which includes physical and built environments,
as well as the relationship that people have with both of these types of
environments. A person who studies this subject is known as a geographer.

As geography covers a wide range of topics, it is commonly organised into

two main branches:
• physical geography • human geography

What Is
Geography?

What Is Physical What Is Human

Geography? Geography?

Physical environment Built environment

• Atmosphere • Housing
• Hydrosphere • Transport systems
• Lithosphere
• Biosphere

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 5

How Do Geographers
Understand the World?

What Are What Is

Geographical Geographical
Concepts? Inquiry?

• Space • Pose geographical

• Place questions
• Environment • Conduct geographical
• Scale investigation

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 ONE
What Is Physical
6
Geography?
Physical geography is the branch of geography
that focuses on the study of the physical
environment. The physical environment consists
of all living and non-living things that are found
naturally, as well as the natural processes that
occur on the earth.

The physical environment has four components:

• atmosphere

• hydrosphere

• lithosphere

• biosphere

hydrosphere

SecGeoEX_NA_Course1_Ch1_3rdpf.indd 6 06/07/20 6:06 PM

 atmosphere 7

Figure 1.1 Photographs showing the

four components of the
physical environment

biosphere

lithosphere

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 WHAT IS THE ATMOSPHERE?
The atmosphere is the layer of gases and tiny particles that
surrounds the earth. Some examples of gases that make up
the atmosphere are nitrogen, oxygen and carbon dioxide.
8 It is further divided into five layers troposphere,
stratosphere, mesosphere, thermosphere and exosphere.

The condition of the atmosphere at a given time

and place is known as weather, which includes
temperature, humidity, rainfall and wind.

Geo-Fact
The atmosphere has many layers.
• troposphere: The lowest layer of the earth’s atmosphere. Most clouds,
precipitation and other weather elements occur within this layer.
• stratosphere: The layer of the earth’s atmosphere above the troposphere.
Within the stratosphere, temperature usually remains constant.
• mesosphere: The layer of the earth’s atmosphere directly above the
stratosphere and below the thermosphere. Throughout the mesosphere,
temperature decreases with height.
• thermosphere: The layer of the earth’s atmosphere above the mesosphere,
extending to the uttermost fringe of the atmosphere. In this layer,
temperature increases sharply in the lower thermosphere, then drops off
and holds steadily with increasing height.
• exosphere: The outermost layer of the earth’s atmosphere.

km
00
,0
90
–1

km
00

7 00
>7

–
re

80
phe

e
er

km
ph
exos

0
–8
os
rm

km
50

0
the

–5
er
ph

m
10

0k
os

3
e

0–
er
mes

ph

km
2

10
0–
tos

er
l ay
stra

troposphere
ozone

Figure 1.2 A diagram showing layers of the atmosphere

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 WHAT IS THE HYDROSPHERE?
The hydrosphere refers to all water found on the earth and in the atmosphere. It includes
water in its solid, liquid and gaseous states. The hydrological cycle enables water to move
continuously between the earth’s surface, the atmosphere and underground.
9

liquid and gas solid

Figure 1.3 Photographs showing various components of the hydrosphere

WHAT IS THE LITHOSPHERE?

The lithosphere is the solid layer of rocks that forms the earth’s surface. It can be up
to a few hundred kilometres in thickness. Magnificent landforms such as mountains
and valleys are created by the movement of large layers of rocks within the lithosphere.

Geo-Fact
Did you know that millions
of years ago, all land on the
earth was joined together
as a supercontinent known
as Pangaea? Over time,
movements within the
lithosphere caused Pangaea
to break up gradually, forming
the various continents that
are recognisable on a world
km map today.

Figure 1.4 A photograph showing rock formations of Hunts Mesa,

Arizona, USA

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 WHAT IS THE BIOSPHERE?
The biosphere refers to all living things on the earth, including plant and animal life, on land and in the
sea. It is dependent on the other components of the physical environment. For instance, plant growth
requires suitable temperature, rainfall and soil conditions.
10

Figure 1.5 A photograph showing wildlife and natural vegetation in Kilimanjaro National Park, Kenya

Figure 1.6 A photograph showing rich marine life in the Indian Ocean near the Maldives

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 TWO
What Is Human
Geography? 11

Human geography is the branch of Geography that involves the study of human life in the built
environment. The built environment is created through human-made changes to the physical
environment. It provides the setting for a variety of human activities and interactions among people.

The built environment has many aspects, such as:

• housing • transport systems

WHAT IS HOUSING?
Housing refers to structures or buildings developed by people to shelter themselves from the elements.
It can be temporary or permanent. An example of temporary housing is a tent in a campsite, while an
example of permanent housing is a block of Housing and Development oard (HD ) flats.

Figure 1.7 A photograph showing tents at a campsite in Figure 1.8 A photograph showing blocks of HD flats in
Pang Tong National Park, Thailand Sengkang, Singapore

Geo-Fact Did you know that nearly 80% of Singapore citizens and permanent residents live in
housing built by the government? As early as 1927, public housing in Singapore began to
be developed by the Singapore Improvement Trust. Then from 1960 onwards, the Housing
and Development Board (HDB) took over the responsibility of developing public housing.

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 WHAT ARE TRANSPORT SYSTEMS?
Transport systems refer to the equipment, infrastructure and networks that support the
movement of people and goods from one location to another. For instance, public buses,
Changi Airport and the Mass Rapid Transit (MRT) network form part of Singapore’s transport system.

12

Figure 1.9 A photograph showing aeroplanes docked at Figure 1.10 A photograph showing MRT trains on
Changi Airport, Singapore above-ground tracks, Singapore

Figure 1.11 A photograph showing container ships Figure 1.12 A photograph showing motor vehicles
berthed at Pasir Panjang port, Singapore along the Pan Island Expressway, Singapore

Questions for understanding

Are the following part of the physical environment or the built environment: beach; park; forest;
reservoir; vegetable farm; volcano? Why do you think so?

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 THREE
What Are
Geographical Concepts? 13

A geographical concept is an important idea

that geographers make use of to understand the
world. There are four key geographical concepts:

• space • environment

• place • scale

Figure 1.13 A diagram showing geographical

concepts, which are like special lenses
through which geographers view and
think about the world

WHAT IS SPACE?
Space refers to a physical area on the earth’s surface. Schools, shopping centres and parks are
found in different physical areas. Geographers may refer to them as spaces for learning, business
and recreation respectively.

Location is an idea that is closely related to space. It can be expressed using a set of coordinates,
which is based on a global system of imaginary horizontal and vertical lines known as latitude and
longitude respectively. For instance, Singapore’s location is 1° North 103° East.
North North
P ole P ole

7 5 °

6 0°
0°

4 5 °
1 5 °

Tro 3 0°
pic o 3 0° 1 8 0°
fC ancer 4 5 °
1 6 5 °
6 0° 1 5 0°
1 5 ° 7 5 ° 1 20° 1 3 5 °
9 0° 1 05 °
S ingapore S ingapore
E q u at E q u at
or or

Tro
pic o 1 5 °
fC apricorn

3 0°

4 5 °
6 0°
S ou th S ou th
P ole P ole

Figure 1.14 A diagram showing latitude on a globe Figure 1.15 A diagram showing longitude on a globe

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 The locations of individual geographical features, such as mountains or roads,
may be arranged across an area in a particular way. This is known as a spatial
pattern. Spatial patterns can be identified as linear or cluster.

14

Figure 1.16a A diagram showing linear pattern Figure 1.16b A diagram showing cluster pattern

Questions for understanding

Using the concept of space, some questions that geographers may explore include:

• Where is a particular feature located on the earth’s surface?

• What is the distance between two features?

• How are the features arranged in this area of study?

Geo-Fact

Did you know that the system of coordinates used to indicate

location was invented by a Greek mathematician and geographer
named Eratosthenes in the rd century CE He was also the first
person to accurately measure the circumference of the earth!

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 WHAT IS PLACE?
Place refers to an area of the earth’s surface that holds special meaning for people. For example, people
are likely to consider the neighbourhood they grew up in or the primary school they attended as special
places. As these places were settings for daily activities that they used to take part in, they would have
developed memories and feelings towards those places over time.

15

Figure 1.17 A photograph showing the Marina Floating Platform where a few National Day Parades were held is
a place special to Singaporeans

Geographers use the concept of place when studying

people’s relationships with the physical and built
environments. Some questions that might be asked include: Questions for reflection
• Who are the groups of people in this place?
What are some places which
• How do they view and feel about this place? What are hold special meaning for you?
some reasons for their views and feelings? Why are they significant to you

• How can this place be improved for the people?

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 WHAT IS ENVIRONMENT?
Environment refers to the physical and built environments, as well as the
processes that occur naturally or result from human actions. Geographers
are interested in studying the interactions between humans and the
physical or built environments. They are keen to find ways to minimise the
negative impacts of humans on these environments.
16

Pulau Ubin
Chek Jawa
Wetlands

Figure 1.18 A map of Pulau Ubin, Singapore

Situated at the south-eastern tip of Pulau Ubin, Chek Jawa

is a unique natural area that contains rich animal and plant
life. Boardwalks and viewing towers were constructed
to allow people to enjoy its natural beauty, as well as to
prevent them from damaging its fragile environment.

Geographers may ask these questions when they

apply the concept of environment: 1 kilometre
K ey
North B oardw alk I ntertidal area
• What are the attributes or
characteristics of the environment? P ath M angrove

B ou ndary C het Ja w a w etlands

• How and why is the environment

changing? What processes are
occurring here?

• What can be done to minimise

the impact of humans on the
environment?

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 WHAT IS SCALE?
Scale refers to the level of detail at which geographers 17
study something. There are three different types of scale
that geographers often use.

Map scale
Maps are diagrams that represent features of the physical
and built environments, such as rivers and cities. Map scale
is the relationship between a distance on a map and the
actual distance on the ground. It can be expressed as a
representative fraction or as a statement. For instance,
a 500-metre-long road may be represented as being
5 centimetres long on a map. The map scale in this case is
Figure 1.19 A photograph showing the thus “1:10,000” or “1 centimetre represents 100 metres”.
physical environment of
Chek Jawa, Singapore

EURO P E NORTH
ASIA AMERICA

A FRI CA

SO UT H
A ME RI CA
AUST RALIA

ANTA RCT ICA Scale 1: 170,000,000

5,000 km

Figure 1.20 A photograph Figure 1.21 A map showing continents of the world
showing constructed
boardwalk for people
to enjoy Chek Jawa
without destroying its
fragile environment,
Singapore

SecGeoEX_NA_Course1_Ch1_3rdpf.indd 17 07/07/20 2:10 PM

 Geo-Fact Contour lines refer
to lines found on a
1 0
0 map joining points
8 0
of equal height
6 0
4 0
above or below
4 0
4 0
sea level.

18 Upper Pierce
Rese rvo ir
20

4 0
4 0

B uk it Tim ah Hil l
1 6 1 6 5 m
0
1 4 1 6 0 6 0
0
1 4 0
4 0
1 2
0 B uk it Tim ah Nature Res erv e
1 0
0
1 00

1 20 8 0
1 2
8 0
6 0

6 0
4 0

8 0
0
1 0 6 0
6 0
4 0

8 0
6 0 8 0 4 0
4 0

6 0
4 0

8 0 1 millennium (1,000 years)

6 0
4 0
6 0 4 0 4 0
4 0
4 0 20

20
20
20

Figure 1.22 A topographic map showing the relief, vegetation and roads at
Bukit Timah Nature Reserve, Singapore 1 century (100 years)
5 00 metres
K ey
North C ontou r line

4 0 E lev ation in metres

Empress Esplanade
Lawn Bridge

1 decade (10 years)

Asian Jubilee
a de

Anderson Bridge
Civilisation Bridge
E s pl an
D r i ve

Museum
S

Empress The Fullerton

i n
Circ

Place Waterboat House

g
ular

p
a

o Merlion
Ro

r e Park
ad

No The Fullerton
d

So rth C R i
oa

Hong Lim u th a n v e r Hotel

o ad
eR

Ca al R
Park na
l R oad
idg

Maybank
on R

oa
Br

One d One
Chartered BOC
lert

George Street
uth

Fullerton
UOB UOB Bank
So

Ful

Pickering Plaza UOB Plaza Building

Tower 1 Plaza Tower 2 ad
Pic Operation Ro
ke ry
r i n Complex OCBC Royal One tte MYP HSBC
gS Ch u lia S Ba
tre Centre Phillip tre et Centre
e
Great Eastern t Royal Group One Singapore
Centre Building Land Tower Tung The Fullerton
ay

Raffles Centre Pavilion

u

Yueh Hai Ching Place

rQ

Temple Grand Bank of

ll y e

Building Singapore Oxley Change

Raffles
Ch @Raffles Alley M a r i n a
Co

Centre
Capital Capitaspring Place Clifford Pier
ur

(U/C) Park Clifford OUE

ch

Square Ma l ac c a S t r e Centre Link B a y

St

et
et

ree

The Arcade
re

Bharat OUE
St

Samsung Building Tower

ina

ay

Cr
e

Hub Ocean The Fullerton

t re

os
Ch

Qu

sS
Plus Republic Towers Bay Hotel
rS

tre Plaza
et
er

OUE
ye

China
ua

lly
kA

Bayfront
Q

Square Prudential
Co

e r
y
lo

Tower i l Stre e t ll Old Customs

Co
Te

1 year (12 months)

ec The Finlayson House
Manulife C Quadrant Green Clifford Pier Lighthouse
d

Tower One Marina

oa

Ascott Raffles Blvd

nR

Cr
os Place M
sS
ay
so

tre AIA ar
CapitaGreen ina
u
bin

et Tower
sQ

18 Bo The Promontory
1 week (7 days)
Ro

ule
ff l e

Telok Ayer Robinson One Raffles va

rd @Marina Bay
Ra

Green Quay

Figure 1.23 A street map of Raffles Place, Singapore

100 metres
Key
North
Building

SecGeoEX_NA_Course1_Ch1_3rdpf.indd 18 06/07/20 6:06 PM

 Geo-Fact Did you know that the earth is estimated to be around 4.6 billion years old?
The geologic time scale divides the earth’s history into intervals such as the
Jurassic Period, which lasted from about 200 to 145 million years ago and
was during the time when dinosaurs dominated the earth.

19

Time scale
Time scale is the period of time
during which something happens.
Geographers need to consider
time scale because processes and
changes in the physical and built
environments occur at a variety of
time scales, from seconds to weeks,
to decades and even to millennia.

1 month (30 days)

1 day

Figure 1.24 A diagram showing different time scales

SecGeoEX_NA_Course1_Ch1_3rdpf.indd 19 06/07/20 6:06 PM

 Geographic scale
Geographic scale is the spatial extent of something. It is often divided into the local, national,
regional and global scales. For example, a village or town centre is considered to be at the local
scale. The national scale includes the whole country, whereas the regional scale covers a group
of countries that are located close to one another, such as Southeast Asia. The global scale
refers to the entire world.

20 Geographers can study features or processes in the physical or built environments at one of
these geographic scales or even across several of them.

global

regional

national

local

Figure 1.25 A diagram showing local, national, regional and global scales

Geographers may ask these questions when they apply the concept of scale:

• Which areas are affected by this phenomenon?

• What timescale does this phenomenon operate on?

• Does this phenomenon occur at the individual, local or national level?

SecGeoEX_NA_Course1_Ch1_3rdpf.indd 20 06/07/20 6:06 PM

 FOUR
What Is Geographical
Inquiry? 21

Geographical inquiry is an approach that geographers take to understand the world. It involves:

• posing geographical questions; and • carrying out geographical investigation.

HOW DO GEOGRAPHERS POSE

GEOGRAPHICAL QUESTIONS?
The words who, what, where, when, why and how are commonly used to form questions. These question
words can be used together with the four key geographical concepts to pose geographical questions
about a phenomenon and any issue that it may cause. A phenomenon is a feature or situation that can
be observed to exist or happen in the physical or built
environments, such as a waterfall or traffic congestion.

WHO
– is being
affected by it?
– is trying to
HOW manage it?
– does it WHAT
occur? – is it?
– does it change – issues could it
over time? cause?
– can it be – should people
managed? do about it?

PHENOMENON

WHY
WHERE – does it occur?
– is it found? – does it affect
– is it causing people?
issues? – does it affect the
environment?

WHEN
– does it occur?
– does it cause
issues?

Figure 1.26 A diagram showing geographical

questions on a phenomenon

SecGeoEX_NA_Course1_Ch1_3rdpf.indd 21 06/07/20 6:06 PM

 HOW DO GEOGRAPHERS CONDUCT
A GEOGRAPHICAL INVESTIGATION?
A geographical investigation is a systematic study that is carried out to find possible
answers to the geographical questions posed. It consists of five different stages.

22

STAGE 1:
Framing the • Pose geographical questions to decide on the focus of the
geographical geographical investigation.
investigation

• Decide what types of primary and secondary data need to be

STAGE 2: collected in order to answer the geographical questions posed.
Collecting • Determine which methods will be used to collect required data to
data ensure accuracy and reliability of data.

STAGE 3: • Organise raw data collected, process and present them using maps,
Analysing and field sketches and suitable graphical representations such as tables
presenting and graphs.
data • Make sense of the data by identifying patterns or relationships.

STAGE 4:
• Provide evidence-based responses to the geographical questions
Drawing
posed at the start.
conclusions

Reflect on how Stages 1 to were carried out and evaluate data

STAGE 5: collection methods.
Reflecting
• Suggest ways to improve the investigation.
and taking
action • Propose ways to improve the relationship between the phenomenon
and people.

Figure 1.27 A diagram showing the five stages of a geographical investigation

SecGeoEX_NA_Course1_Ch1_3rdpf.indd 22 06/07/20 6:06 PM

 STAGE 1 STAGE 2
What? Interviews and
When?
Why? questionnaires

Who? Observation Use instruments

Where?
How? data to measure data
23

STAGE 3

STAGE 4 STAGE 5
How can we improve?

SecGeoEX_NA_Course1_Ch1_3rdpf.indd 23 06/07/20 6:06 PM

 CHAPTER GLOSSARY
Atmosphere The layer of gases and tiny particles that surrounds the earth

24 Biosphere All living things on the earth, including plant and animal life

The environment that is created through human-made changes to

Built environment the physical environment and provides the setting for a variety of
human activities and interactions among people

An important idea that geographers make use of to understand

Concept the world

A geographical concept that refers to the physical and built

Environment environments, as well as to the processes which occur naturally or
result from human actions

The study of the earth, which includes the physical and built
Geography environments, as well as the relationship that people have with
them

Geographer A person who studies the subject of Geography

Geographical A systematic study that is carried out to find possible answers to

investigation geographical questions posed

Geographic scale The spatial extent of something

The branch of Geography that involves the study of human life in

Human geography the built environment

All solid, liquid and gaseous water found on the earth’s surface,
Hydrosphere in the atmosphere and underground

Inquiry An approach that geographers take to understand the world

Issue A subject or problem that people are discussing

Latitude The angular distance of a place north or south of the Equator

Lithosphere The solid layer of rocks that forms the earth’s surface

SecGeoEX_NA_Course1_Ch1_3rdpf.indd 24 06/07/20 6:06 PM

 The exact position of something on the earth’s surface, expressed
Location as a set of coordinates

Longitude The angular distance of a place east or west of the Prime Meridian

The relationship between a distance on a map and the actual

Map scale distance on the ground, expressed as a representative fraction or
statement 25

The particular way in which individual geographical features are

Pattern arranged across an area

A feature or process that can be observed to exist or happen in the

Phenomenon physical or built environments

Physical All living and non-living things that are found naturally, as well as
environment the natural processes that occur on the earth

The branch of Geography that focusses on the study of the physical

Physical geography environment

Place An area of the earth’s surface that holds special meaning for people

Relationship The way in which two or more things are connected

Scale The level of detail at which something is studied by geographers

Space A physical area on the earth’s surface

Time scale The period of time during which something happens

NOTES

SecGeoEX_NA_Course1_Ch1_3rdpf.indd 25 06/07/20 6:06 PM

 CHAPTER

26

How Can W
Manage Na
Learning
Outcomes
In this chapter, we will learn to:
• describe the types of
natural resources; and
• describe the ways people
view and use natural
resources.

A photograph showing the

rainforest and deforestation
in the Amazon

SecGeoEX/NA_Course1_Ch2_PFPB.indd 26 7/7/20 11:16 AM

n We Sustainably
Natural Resources?

SecGeoEX/NA_Course1_Ch2_PFPB.indd 27 7/7/20 11:16 AM

 How Can We Sustainably
28

What Is a What Is a Natural

Resource? Resource?

How Do People How Are Natural

Identify Resources? Resources Classified

Culture Technology Renewable Non-renewable

SecGeoEX/NA_Course1_Ch2_PFPB.indd 28 7/7/20 11:16 AM

 Manage Natural Resources?
29

How Do What Does How Can We

People’s Sustainable Use Natural
Views Affect Use of Resources
the Use Natural Sustainably?
of Natural Resources
Resources? Mean?

Nature-centred Human-centred Conservation Technological

development

SecGeoEX/NA_Course1_Ch2_PFPB.indd 29 7/7/20 11:16 AM

 ONE
What Is a Resource?
30

A resource is a material that is identified by people that fulfils our needs for survival. Resources also
to be useful. When this material is made into enable tasks to be carried out.
a product, the product can be considered
a resource as well because it is useful too. We use metal and plastic to make products such
Resources can fulfil people’s needs and enhance as mobile phones and tablets. These products
their well-being. For example, food is a resource can be considered resources as they enhance

Reading Calling and online Browsing social

90% personal emails 79% messaging 71% media and networks

SecGeoEX/NA_Course1_Ch2_PFPB.indd 30 7/7/20 11:16 AM

 Questions for understanding

What are two or three resources that you and

your family use on a daily basis?

What are two or three resources which you

cannot do without? What are the reasons for
your choices? 31

our well-being and enable tasks to be carried out.

Mobile phones allow us to complete tasks such Figure 2.1 An infographic showing the percentage of
as sending text messages, planning journeys with people using their mobile phones for various
transport apps and searching for information activities, based on a 2017 Singapore study
on websites. of 1,000 people aged 18 to 69.

Responding to Reading the news

57% work or business 53% and sports updates

SecGeoEX/NA_Course1_Ch2_PFPB.indd 31 7/7/20 11:16 AM

 HOW DO PEOPLE IDENTIFY RESOURCES?
What is a resource to one
group of people might not be
for another group. Culture and
technology can shape how we S o u t h C h i n a S e a
decide if a material or an object
32 is useful to people.

Culture
Culture refers to the way of
SINGAPORE
life which a group of people
share. For example, the Penan B O R N E O
tribe are a group of hunters
and gatherers who live in the
tropical rainforests of Borneo,
an island to the east of
Singapore. Wood from trees is
used to build their houses and
as firewood. In comparison,
N

J a v a S e a
we use bricks, cement and steel
bars to construct our houses in 200 kilometres

Singapore. We also use gas or 200 miles

electricity for cooking. Based on

our lifestyles, we identify gas,
Tropical rainforest in Borneo, 2015
cement, steel bars and electricity
as resources. However, for the
Penan, who do not use these
Figure 2.2 A map showing the location of Borneo
items often, they may not even
consider them as resources.

Figure 2.3 Photographs showing how the Penan tribe uses wood from trees
to build houses and as firewood

SecGeoEX/NA_Course1_Ch2_PFPB.indd 32 7/7/20 11:16 AM

 Technology
Technology can influence people’s ability to identify resources. efore machines were invented,
animals were used for laborious work. In parts of Southeast Asia where rice is a major food
crop, rice farmers used to rely mainly on water buffaloes and simple tools to plough the fields
and till the land. Now, however, machinery such as power tillers and combine harvesters are
increasingly being used. Thus, water buffaloes are less likely to be seen as a valuable resource.

Figure 2.4 A photograph showing water buffaloes Figure 2.5 A photograph showing a sickle for harvesting
for ploughing

Figure 2.6 A photograph showing a tractor Figure 2.7 A photograph showing a combine harvester
for ploughing for harvesting

We now know that resources are identified when people find a use for them.
In the next section, we will learn more about natural resources in particular.

SecGeoEX/NA_Course1_Ch2_PFPB.indd 33 7/7/20 11:16 AM

 TWO
What Is a
34
Natural Resource?
Natural resources are useful materials
Questions for understanding
found on Earth. They are produced
by natural processes occurring in the
What are some products which you use daily?
physical environment. Water and solar
What are the natural resources used to make these
energy are examples of natural resources.
products? How are these natural resources obtained?

A PV cell is a specially-treated
1 wafer of silicon, sandwiched
1
between two thin contact
plates. When sunlight hits
the solar cell, solar energy
passes through the silicon
and an inverter to generate
electricity that we can use.

DC

AC

How Solar Energy Works

Every second, the Sun gives off about 400 trillion watts of solar
energy. A lot of the Sun’s energy is reflected back into space or
absorbed by the Earth’s atmosphere, but an average of 1,000 watts
of solar energy per square metre per hour still reaches the Earth’s
surface during peak times. Solar panels, or photovoltaic (PV) cells,
convert this solar energy into electricity.

SecGeoEX/NA_Course1_Ch2_PFPB.indd 34 7/7/20 11:16 AM

 HOW ARE NATURAL
RESOURCES CLASSIFIED?
Natural resources can be classified into two categories renewable and non-renewable.

Renewable 35
Renewable natural resources refer to materials that replenish naturally more or less within the same time
period when they are used. The availability of renewable resources, which refers to the amount that
exists, is considered to be unlimited. We may wonder why it is so. When a renewable natural resource
is used by people, its availability is reduced. At the same time, natural processes continually occur to
replenish the resource. Hence, its availability is increased again after some time.

Water and solar energy are also examples of renewable natural resources. Energy from the sun is
captured by solar cells, which convert it into electricity that we can use. As sunlight is received daily,
solar energy that is used up at the end of each day can be replenished the next day.

To learn more about

this chapter, check
out this lesson on the
Singapore Student
Learning Space.
go.gov.sg/lsg002

2
The electricity produced
2 is measured through the
meter and then fed into
the public electricity grid.

Figure 2.8 A diagram showing how solar energy is harnessed

SecGeoEX/NA_Course1_Ch2_PFPB.indd 35 7/7/20 11:16 AM

 Non-renewable Geo-Fact
Non-renewable natural resources refer to materials which
may or may not replenish naturally. If they are replenished,
The Earth provides people with many
then the natural processes occur very slowly and takes such
natural resources that can then be
a long time that it is beyond the period used. As such, the
turned into products. Here are three
availability is considered to be limited. of the most commonly mined minerals
36 from Africa and their uses:
An example is crude oil. As crude oil takes millions of years • quartz: used in the manufacturing of
to form, the rate of replenishment is too slow to increase its glass, paints and prism lenses etc.
availability in the near future. Crude oil is a dark and sticky • bauxite: commonly converted
liquid that is obtained by drilling into oil wells located on to aluminium and used in the
land or in the sea. We cannot use crude oil directly. Instead, manufacturing of automobiles,
it must be refined before it is useful to people. Petrol is one construction and packaging etc.
of the most common products obtained from crude oil. It is • cobalt: used in combination with
used to power motor engines in vehicles. As people extract other minerals in the manufacturing
crude oil from the Earth, its availability is reduced. of aircraft gas turbine engines and
cutting tools etc.

A few hundred million years ago, the remains of plants and Over many more millions
animals sank down to the ocean floor in large quantities of years, the layers of sand
and were gradually buried by layers of sand and silt. and silt turned into rock, and
buried the remains deeper
and deeper into the Earth.
This process subjected
the remains to enormous
pressure, and together with
thermal energy from the
Earth, converted the remains
into crude oil.

crude oil

SecGeoEX/NA_Course1_Ch2_PFPB.indd 36 7/7/20 11:16 AM

 Figure 2.6 A diagram showing the formation of crude oil

Questions for understanding

How would you classify the following natural resources? Give a reason for your choice.
37
Natural Resource Renewable / Non-renewable Reason

Coal

Fish

Wind

Figure 2.9 A diagram showing the formation of crude oil

Modern oil rigs drill deep

into the Earth to extract
the crude oil deposits.

oil drill
equipment

crude oil

SecGeoEX/NA_Course1_Ch2_PFPB.indd 37 7/7/20 11:16 AM

 THREE
How Do People’s
38 Views Affect the Use
of Natural Resources?
The use of natural resources is influenced by people’s views. This can be nature-centred or human-
centred. The Penan tribe mentioned earlier in this chapter relies on the forest to provide their daily
needs. They are likely to value the physical environment as important and precious. They will thus ensure
that it is not damaged by their activities. Other people may not share the same view as the Penan tribe.

NATURE-CENTRED
In the nature-centred view, the physical environment with its natural resources is seen as valuable in
itself. Everything that is naturally found in the physical environment, such as trees, animals, rivers and
mountains, is as important as humans. Therefore, the physical environment should be preserved,
meaning it should be protected and retained in its original state as far as possible. People’s use of the
physical environment should be minimised and even prohibited.

Although Singapore does not rely on forests to the same extent as the Penan tribe, Singapore
acknowledges the importance of preserving our native rainforest trees, plants and animals through the
creation of nature reserves. People cannot utilise the natural resources found in these areas. The cutting
down of trees or removal of plants and animals within these areas is against the law because such actions
can cause damage to the physical environment and the valuable resources within. We will learn more
about the Parks and Trees Act in Chapter 6.

Figure 2.10 Photographs showing the Central Catchment Nature Reserve and the Parks and Trees Act

Geo-Fact Fish is a good source of protein. Protein helps people to build bones and muscles.
As the world’s population increases and people are able to afford a better diet, demand
for fish has also increased. As a result, some species are overexploited, meaning they
are being fished at such high levels that their supply is likely to become non-renewable.
According to the Food and Agriculture Organisation of the United Nations, some of the
overexploited species in Asia are bluefin tuna, Indian mackerel and giant tiger prawn.

SecGeoEX/NA_Course1_Ch2_PFPB.indd 38 7/7/20 11:17 AM

 39

HUMAN-CENTRED
In the human-centred view, the physical environment is valuable because humans can obtain materials
from it for people’s use and benefit. People with this view are motivated to find ways to extract these
natural resources to enhance their personal well-being or to sell them in exchange for money.

However, extraction of natural resources can cause negative impacts on the availability of the resources
and the physical environment. If extraction occurs at a faster rate than natural renewal, the availability
of the natural resource will be depleted. Environmental degradation can occur too. In the example of
tropical rainforests, trees are habitats for animals and plants. When large areas of rainforests are cleared,
the survival of animals and plants will be threatened. Some may eventually become extinct. Also, the
roots of trees hold soil together. Without trees, soil can be easily washed into rivers, in turn affecting
aquatic life.

‛m not sure i that‛s

a goo i ea. ith so
many o us going own
to the mu ats an
catching creatures …
For our CCA camp during the we could damage the
holi ays, let‛s go to ulau bin. natural en ironment
e can bring the uniors Yeah, we can go down to
to explore Chek the mu ats an catch
awa. some creatures.
t‛ll be un

That
sounds like
a great
i ea

Figure 2.11 A comic strip showing students’ views toward natural resources

Questions for understanding It is possible that we share different views about the use of natural
resources as well as the importance of the physical environment
From the comic strip above, can from the people around us. Even so, we can be respectful towards
you identify the views held by each others’ views and be open to changing our minds as we learn more.
student? What makes you say that?

SecGeoEX/NA_Course1_Ch2_PFPB.indd 39 7/7/20 11:17 AM

 FOUR
What Does Sustainable
40 Use of Natural
Resources Mean?
Sustainable use of natural resources refers to actions
people can take to ensure that the natural resources
we have on Earth today continue to be available for
future generations.

When we extract natural resources from Earth in the

short term, that is over the next few years, we need
to be aware of the possible impact in the long term
for the next 10, 20, 30 or more years. We will then
be careful about the amount of natural resources
we are using now. We can also try to reduce the
environmental degradation that may occur.

If we are using some natural resources at a much

faster rate today than it can be naturally replenished
over time, what may happen in the future? Can
renewable natural resources become non-renewable?

The answer is yes. A renewable natural resource

can become non-renewable if we use it at a faster
rate than it can be naturally replenished. Hence,
its availability changes from unlimited to limited.
An example is tropical rainforests. Wood from tropical
rainforest trees is useful for many purposes such as
the manufacture of furniture and paper products.
To meet people’s demand for wood, trees are being
cut down at a much faster rate than it can be naturally
grown back. If this continues, there is a chance that
tropical rainforests may become non-renewable.
We will discover more about the characteristics and
uses of tropical rainforests in Chapter 6.

As for non-renewable resources, their availability

may fall to very low levels or even become depleted. kapok tree
When this happens, our future generations will not 20 years to grow to
be able to make use of them. They may have to seek maturity. Up to 50 m tall.
alternative resources. To avoid such a situation, we
can take actions towards sustainable use.

Figure 2.12 An infographic showing time taken for

rainforest trees to grow to maturity

SecGeoEX/NA_Course1_Ch2_PFPB.indd 40 7/7/20 11:17 AM

 Questions for reflection
60 m
In what ways does the
physical environment
affect humans? How do
humans affect the physical
environment?

How would you describe

humans’ relationship with
the physical environment? 50 m

40 m

30 m
shorea
acuminata tree
30–40 years to oil palm
grow to maturity. 2–3 years to grow to
Up to 60 m tall. maturity. Up to 20 m tall.

20 m

custard apple tree

5 years to grow to
maturity. Up to 10 m tall.

10 m

0m

SecGeoEX/NA_Course1_Ch2_PFPB.indd 41 7/7/20 11:17 AM

 FIVE
How Can We tons

15
travel
e.g. air travel, car fuel
14.50 tons

42 Use Natural
Resources home
e.g. electricity, water
11.97 tons

Sustainably?
Two things we can do to use natural resources
sustainably are to encourage conservation
10
and to develop technologies to manage our
environmental footprint.

CONSERVATION
Reduce
We can reduce our consumption of some
products, which in turn reduces the amount of
natural resources used. Natural resources are
required in the manufacturing processes of
most, if not all, the products we use daily. To
manufacture clothes, factories need electricity 5
and lights as well as water for the dyeing of
fabrics. Waste gases such as nitrogen oxide,
sulphur oxide and carbon dioxide are released
when diesel is burned to power machines.

Scientists developed the idea of environmental

footprint to enable people to measure the land
area that is required to make a product as well
as absorb the waste that is generated.

Products have different environmental

footprints. This indicator enables us to compare
between products, be more aware of our
impact on the physical environment and to make 0
decisions about our consumption. If we are
concerned about the sustainability of natural
resources, we can choose those products with a 1 ton 0 kg
smaller environmental footprint.

SecGeoEX/NA_Course1_Ch2_PFPB.indd 42 7/7/20 11:17 AM

 Reuse
Reusing a product or material reduces
the need to buy new or additional pieces.
For example, cardboard boxes can be
repurposed to store our household items.
In this way, we require less of natural
resources, such as wood from trees.
43

total 56.91 tons

services
food e.g. restaurants, Figure 2.14 A photograph showing used
e.g. fruit, meat laundry services tyres reused as planter pots
and vegetables 6.02 tons
7.00 tons goods
e.g. furniture,
clothing
6.79 tons

Figure 2.15 A photograph showing wooden

crates made into furniture

Figure 2.13 A diagram showing the carbon footprint of

an average American household, 2007
(Numbers are in carbon dioxide equivalent Figure 2.16 A photograph showing old plastic
per year) bottles reused for handicrafts

SecGeoEX/NA_Course1_Ch2_PFPB.indd 43 7/7/20 11:17 AM

 Recycle
Recycling turns used materials into new and useful ones. Common materials which are recycled include
glass, aluminium and paper. These materials are widely used in drinks packaging. Aluminium comes from
a mineral called bauxite, which must be chemically refined before use. Large amounts of electricity and
fossil fuels are required to manufacture this material. When we recycle aluminium drink cans, the material
can be reused. Overall, the need for bauxite can be reduced.
44 Processing aluminium from bauxite

1 The ore bauxite is mined

from the Earth, crushed
into manageable chunks
and sent to the refinery.

1 2
Recycling aluminium to reduce need for bauxite

1 Aluminium packaging
is collected for
recycling and taken
to a treatment plant.

1 2
Figure 2.17 Diagrams showing how aluminium is processed and recycled

Recover
You can also recover useful materials from
waste we produce. An example is food or
plant waste composting. These materials
are collected and stored in a container.
They are decomposed by bacteria and
fungi into nutrient-rich fertilisers. In this
way, you can reduce the amount of waste
that needs to be incinerated or disposed
of in landfills.

Figure 2.18 A diagram showing some facts about Pulau Semakau

SecGeoEX/NA_Course1_Ch2_PFPB.indd 44 7/7/20 11:17 AM

 Questions for Can you think of other examples of actions to reduce, reuse, recycle and recover?
understanding
Reduce

Reuse

Recycle

Recover 45

2 At the refinery, bauxite is 3 At the smelting factory,

ground into a fine powder and the aluminium oxide
refined to extract aluminium goes through chemical
oxide. The aluminium oxide is processing and electrolysis
then sent for smelting. to split it into aluminium
and oxygen. The resulting
aluminium is then cast into
blocks, ready to be used.

2 At the plant, the aluminium 3 The molten aluminium is then

is cleaned and sorted, then cast into blocks, ready to be
melted down into molten used again.
aluminium.

1st man-made offshore landfill, created out of sea space.

Home to more than 700 types of plants and animals, including several endangered species.

Only landfill in Singapore.

We send 200,000 tons of waste and ash to the landfill every year.
At this rate, the landfill will run out of space by about 2035.

SecGeoEX/NA_Course1_Ch2_PFPB.indd 45 7/7/20 11:17 AM

 TECHNOLOGICAL DEVELOPMENT
Technology can influence our ability to identify and make use of resources. Technological development
can lead to the discovery of more efficient uses of natural resources so that our environmental footprint
can be reduced.

Take solar power for example. The invention of the solar cell in the 1950s enabled us to turn sunlight into
46 electricity. At that time, the amount of electricity was enough to power small devices such as radios.
As research continued, scientists found ways to make solar cells smaller, cheaper and more efficient.
Today, solar cells can be found in many products, including cars. People can also buy or rent solar panels
on the rooftops of their homes to generate electricity.

Figure 2.19 A photograph showing solar panels on top of an HDB multi-storey carpark
in Clementi, Singapore

Figure 2.20 A photograph showing solar panels

on a stadium in Taiwan

SecGeoEX/NA_Course1_Ch2_PFPB.indd 46 7/7/20 11:17 AM

 47

Figure 2.21 A photograph showing floating solar panels in Thailand

Questions for reflection

Think back on an action you might have taken that has some impact on the physical
environment. In this case, how would you describe your view towards the physical environment?

What is one natural resource that is most important to you? What makes you choose it?

SecGeoEX/NA_Course1_Ch2_PFPB.indd 47 7/7/20 11:17 AM

 CHAPTER GLOSSARY
The management and use of a resource or an environment in a
Conservation responsible and efficient way
48

Consumption People’s use of resources due to decisions they make

Depletion The reduction in the availability of a natural resource

Environmental The negative consequences which occur in the physical

environment. Often, this is due to human actions.
degradation

Environmental A way of measuring the land area that is required to make a

footprint product for people’s use and to absorb the wastes produced

The removal of natural resource from its original location, usually

Extraction for people’s use

Human-centred A way of viewing the physical environment as useful because it

provides materials for people’s use and benefit
view

The materials which are found on Earth and are produced by

Natural resource natural processes occurring in the physical environment

Nature-centred A way of viewing the physical environment as being valuable in

view itself and not because of its usefulness to people

Describes the natural resources which replenish naturally over a

Non-renewable long time that is beyond the period it is used

The management of a resource or environment for protection and

Preservation retaining its original state as far as possible

Describes the natural resources that replenish naturally more or

Renewable less within the same time period that it is used

SecGeoEX/NA_Course1_Ch2_PFPB.indd 48 7/7/20 11:17 AM

 Short and The period of time during which something happens in relative
terms, e.g. Short term can be from seconds to weeks while long
long term term can be decades to even millennia

The use of natural materials in a way that ensures its supply

Sustainable use continues into the future 49

The use of scientific discovery and knowledge of inventions for

Technology practical purposes

A set of attitudes and beliefs towards something that is important

Value and precious, which can, in turn, affect people’s choices and
actions

Waste Unwanted or unusable materials

NOTES

SecGeoEX/NA_Course1_Ch2_PFPB.indd 49 7/7/20 11:17 AM

 CHAPTER

50

Learning
Outcomes
In this chapter, we will learn to:
SPATIAL D
• identify the physical states
of water;
• describe the distribution
of various water stores
using maps or schematic
diagrams;
• explain how the hydrological
cycle ensures a continuous
supply of water using
schematic diagrams; and
• explain water balance using
schematic diagrams.
(OPTIONAL FOR NORMAL
(ACADEMIC) STUDENTS)

A photograph showing people

kayaking at Kallang River

SecGeoEX/NA_Course1_Ch3_PFPB.indd 50 7/7/20 11:32 AM

DISTRIBUTION

SecGeoEX/NA_Course1_Ch3_PFPB.indd 51 7/7/20 11:32 AM

 Water and its
52

What Are the Where Is

Physical States Water Found?
of Water?

• Solid • What Are Water Stores? Input

• Liquid • What Are Oceans?
• Gas • What Are Glaciers?
• What Are Lakes?
• What Are Rivers? Precipitation
• What Is Soil?
• What Is Groundwater?

SecGeoEX/NA_Course1_Ch3_PFPB.indd 52 7/7/20 11:32 AM

 Spatial Distribution
53

What Is the What Is Water

Hydrological Budget?
Cycle?

Flows Output Water Balance

in a Catchment

Infiltration • Discharge into the sea • Water surplus

• Percolation • Evaporation Water deficit
• Surface runoff • Transpiration
Groundwater flow
Channel flow

SecGeoEX/NA_Course1_Ch3_PFPB.indd 53 7/7/20 11:32 AM

 54

Desperate for Water

The following is a true recount of a person living in a water-deprived area.

DAY ZERO
It’s 3.30 a.m. I have to wake up. The last time I woke up after 4 a.m., the city pipe was already
turned off. I hate walking along the dirt path to collect water so early in the morning. But I need
to fill my two buckets so that I can cook, drink and wash my clothes. It hasn’t rained in weeks.
I don’t know when the city government will cut off our water supply. Sometimes, the water I
collect is so green that I wonder if I can use it. I feel tired all the time, but I know I cannot be lazy.

Saving water is a must. I would bathe in a bucket, use the same water to wash my clothes, and
finally flush the toilet with it.

On days when there is not enough water, I don’t flush the toilet. Instead of a bath, I’d wet an old
shirt so I can pat myself clean. Once, I used leftover water to cook. I ended up vomiting for two
days. I wish I had starved instead.

I’m always thirsty. I’m always hungry. There’s not enough food since there isn’t enough water to
grow crops or rear animals. I pray for rain all the time. There were months when it rained a lot,
so we had lots of water to use. But now that the
rain has gone, our wells are dry.

I don’t understand why the government does not

To learn more about
give us clean water. I thought that there is a lot this chapter, check
of water on Earth. Where is it? Why can’t I get it? out this lesson on the
Please help me get it. Singapore Student
Learning Space.
go.gov.sg/lsg003

SecGeoEX/NA_Course1_Ch3_PFPB.indd 54 7/7/20 11:32 AM

 ONE
water vapour
What Are the
Physical States 55

of Water?
water vapour

condensing

evaporating
Water exists in solid, liquid and gaseous states.

SOLID liquid
When it is hot, some of us may want a glass of iced water. The ice
that we see is water in its solid state. Under cold temperatures, water
water droplets freeze into ice. We can also see ice in snow, glaciers
and hail.
melting

ice freezing

Figure 3.1 A photograph showing Figure 3.2 A photograph showing

solid
cars covered in snow in hailstones collected after
Bucharest, Romania a hailstorm

LIQUID Figure 3.3 A diagram showing

how water changes its
When we turn on the tap to get water, we see water in its liquid states through melting,
state. Water in its liquid state appears as water droplets. We can freezing, evaporating
also see water droplets when it rains, and in rivers or reservoirs. and condensing

GAS
When water boils, we see a cloud of mist that is made up of water droplets. What we cannot see is
steam, which is made up of water vapour. Water vapour is water in its gaseous state. Since evaporation
occurs all the time and at any temperature, water vapour is always in the air around us.

SecGeoEX/NA_Course1_Ch3_PFPB.indd 55 7/7/20 11:32 AM

 TWO
Where Is Water Found?
56

Water on Earth is most commonly found in water stores.

WHAT ARE A R C T I

WATER
STORES? Alps Mountains
Ural Mountains
Caucasus Mountains
Water stores are places where
water is contained in and can
be categorised as freshwater Himalayan Mountains
and saltwater stores. Glaciers,
rivers, lakes, groundwater and
soils contain freshwater, which
means that they contain water P A
with low amounts of salt that can
be used more readily. Oceans Mount Kilimanjaro
are saltwater stores, which means I N D I A N
that the ocean water has too
much salt to be used directly. O C E A N

Water stores are not evenly

distributed on the Earth’s Glaciated area
surface. However, water can
move from one store to another.
These movements are known as S O U T H E R N O C E A
flows. For example, glaciers may
melt and flow into rivers, which
eventually flow into oceans. Antarctica

Questions for WHAT ARE OCEANS?

understanding Oceans are large masses of water that are connected to one
another. There are five oceans in the world. The largest ocean is the
Where does the water in your Pacific Ocean, which is surrounded by countries in Asia, Oceania
water bottle come from? and the Americas. The second largest ocean is the Atlantic Ocean,
What are Singapore’s which separates countries in the Americas from Europe and Africa.
water stores? The third largest ocean is the Indian Ocean, which is surrounded by
countries in Asia, Africa and Oceania. Polar bears swim in the Arctic
Ocean, while penguins swim in the Southern Ocean.

SecGeoEX/NA_Course1_Ch3_PFPB.indd 56 7/7/20 11:32 AM

 WHAT ARE GLACIERS?
Glaciers are large masses of ice that rest on land To learn more about
or float in the sea. They are found in places where this chapter, check
it snows throughout the year so that enough snow out this lesson on the
accumulates and hardens into ice. Glaciers move Singapore Student
Learning Space.
slowly because they are very heavy. go.gov.sg/lsg004

Figure 3.4 A map showing major glaciers around the world

Types of Water Stores

A R C T I C O C E A N
Greenland
in the World
Glacier
Saint Elias
Mountains 96.5%
Vatnajökull
Glacier oceans

A T L A N T I C

O C E A N
P A C I F I C O C E A N

Andes
Mountains N
1.03%
1.7%
others
Southern Alps Mountains glaciers
(swamps,
marshes,
O C E A N 0.76% atmosphere)
groundwater
0.002%
a 0.007% rivers
lakes

0.001%
soil moisture

Figure 3.6 A pie chart

showing the
proportion of water
found in different
water stores

Figure 3.5 A photograph showing the Perito Moreno Glacier, Argentina

SecGeoEX/NA_Course1_Ch3_PFPB.indd 57 7/7/20 11:32 AM

 WHAT ARE LAKES?
Lakes are water bodies surrounded by land. Lakes may receive water from rain, snow or rivers.

58
WHAT ARE RIVERS?
Rivers are natural wide flows of freshwater across the land that store water temporarily
before water flows into another water body. They flow from places of higher elevation
to places of lower elevation as gravity pulls water downwards.

The river source marks the point where a river begins, while the river mouth marks
the place where a river flows into another water body. For example, allang River starts
from Lower Peirce Reservoir, and flows into the sea through Marina Channel. Therefore,
Lower Peirce Reservoir is the river source while Marina Channel is the river mouth.

Geo-Fact Did you know that the longest river in Singapore, the Kallang River,
is only 10 kilometres long? Compare this with the largest river in
the world, the Amazon River, which is 6,853 kilometres long!

Figure 3.7 A drawing of the Marina Catchment

river
Lower Peirce Reservoir

river source

SecGeoEX/NA_Course1_Ch3_PFPB.indd 58 7/7/20 11:32 AM

 Geo-Fact The Caspian Sea is named a sea due to its high salt content and vastness.
However, geographically, it is considered a saltwater lake because it is found
inland. It is the world’s largest lake, spanning about 371,000km2.

A R C T I C O C E A N

Lake Baikal Lake Superior

Danu Caspian Great
be River Lake Lakes
Sea Balkhash

Mi River
Ri
llow ver

ssis
Ye

sippi
A T L A N T I C
Me
iver
Ga ze R
Yangt
kon
Riv nges
er
Nile River

O C E A N
gR
iv e

P A C I F I C O C E A N
Lake Victoria
Amazon River

I N D I A N

O C E A N

S O U T H E R N O C E A N

Figure 3.8 A map showing lakes and rivers in the world

Geylang River

Kallang River

river mouth
Marina Reservoir

Marina Channel

Marina Barrage
Marina Bay

Singapore River

SecGeoEX/NA_Course1_Ch3_PFPB.indd 59 7/7/20 11:32 AM

 WHAT IS SOIL?
Soil refers to the loose topmost layer of Earth’s
surface where plants grow. This layer has different
names and contains different materials.
60
When it rains, water passes through the soil through
very small openings known as pores. Water that is
stored in the soil is known as soil moisture.

WHAT IS
GROUNDWATER?
Groundwater is found below the
surface of the Earth. Water
enters the ground through
pores in the soil due to gravity.
Groundwater forms when a part
of this water makes its way to
the rocks beneath, filling up the
pores and cracks of these rocks. well
Countries like China and India
use groundwater to grow crops,
while countries like Indonesia
and Thailand use groundwater
for household activities.

Geo-Fact

Currently, Singapore does

not make much use of its
groundwater. However,
Singapore’s Public Utilities
Board (PUB) has been
monitoring Singapore’s
groundwater levels through
sensors placed in wells to
better understand our ground
water for possible future uses.

Figure 3.9 A cross-section diagram

showing where soil
moisture and groundwater
can be found

SecGeoEX/NA_Course1_Ch3_PFPB.indd 60 7/7/20 11:33 AM

 Questions for
understanding

Have you seen

these weep holes
in Singapore?
What do you think weep holes
they are used for?

Figure 3.10 A photograph

showing weep
To learn more about holes in a
this chapter, check storm canal
out this lesson on the
Singapore Student
Learning Space.
go.gov.sg/lsg005

soil

moist soil

water table

groundwater

bedrock

SecGeoEX/NA_Course1_Ch3_PFPB.indd 61 7/7/20 11:33 AM

 THREE
What Is the
62 Hydrological Cycle?

Precipitation
1 Water falls as rain, or snow
if the air is cold enough.

Surface Runoff
3 Water flows from
highland and over
river source surface of the
ground and into
streams and rivers.

Groundwater
2 Water that seeps into tributaries
water
the ground may be table
absorbed by plants or
stored as ground water.
groun
dwate
r flow

Figure 3.11 A diagram showing the different

processes in the hydrological cycle

Questions for Is water a renewable or

understanding a non-renewable resource?
What makes you say that?

SecGeoEX/NA_Course1_Ch3_PFPB.indd 62 7/7/20 11:33 AM

 The hydrological cycle is a sequence of processes that occur to ensure that water is naturally replenished
on the Earth. Figure 3.11 shows the hydrological cycle of a catchment area. A catchment refers to an area
receiving water, and also contributes water to rivers. 63

Condensation
6 Warm moist air cools as
it rises. Water vapour
changes into water
droplets. Small droplets
combine to form bigger
droplets. Large amounts
of water droplets gather to
form clouds.

Transpiration
5 Plants give out water
vapour through their leaves.

river mouth
Evaporation
4 The Sun’s heat causes
water to evaporate. Water
changes into water vapour.

SecGeoEX/NA_Course1_Ch3_PFPB.indd 63 7/7/20 11:33 AM

 MAL
NOR
A L FO R TS
O P TI
ON U D EN
E M I C) S T
D
(ACA

FOUR
64
What Is Water Budget?
A water budget equation describes the flow of water in and out of a catchment area. In other words, the water
budget tell us how much water is available in an area.

Processes that increase the amount of water in a catchment are known as inputs, while processes that
decrease the amount of water in a catchment are known as outputs. When input is more than output, more
water is received than lost, and a catchment is likely to have more than enough water available. This is known
as water surplus. On the other hand, when output is more than input, more water is lost than received, and a
catchment is likely to have less water available than is enough. This is known as w er e i .

input input

output

Let’s try to think about input and

output in terms of a bathtub.
When you turn on the tap,
you are letting water into the
bathtub. Tap water is the input.
Amount of water Amount of water
What happens when you turn on
increases when input is the tap to its maximum and plug when input
more than output.
the drain? There will be a lot of
input but no output. Since there equals output.
is more input than output, there
is water surplus. The bathtub
starts to fill and may eventually
overflow

SecGeoEX/NA_Course1_Ch3_PFPB.indd 64 7/7/20 11:33 AM

 Geo-Fact Linggiu Reservoir

Did you know that

Singapore draws its water M A L A Y S I A
supply from the Linggiu
Reservoir in Johor,
Malaysia? This reservoir
almost ran out of water in
2017 because there was
not enough rain that year,
leading to water deficit.

SINGAPORE
N

Figure 3.12 A map showing Linggiu Reservoir

input

output
output

What happens when

you turn off the tap and
If you want the amount of water in
unplug the drain? There
the bathtub to remain the same,
will be a lot of output but
you can choose to turn off the tap
no input. Since there is
and plug the drain. There would be
more output than input,
no input and no output. You can
Amount of water there is water deficit.
also choose to turn on the tap and
decreases when input is Water in the bathtub
unplug the drain. As long as the tap

less
starts to drain and there
refills the same amount of water
that flows out through the drain,
than output. will eventually be no
water left in the bathtub!
there will still be enough water left
in the bathtub. When input matches
the output, there is no change in
the amount of water available.

Figure 3.13 A diagram showing the input and output of a bathtub

SecGeoEX/NA_Course1_Ch3_PFPB.indd 65 7/7/20 11:33 AM

 MAL
NOR
A L FO R TS
O P TI
ON U D EN
E M I C) S T
D
(ACA

66

Similarly, in order for a catchment to have enough water all the

time, its inputs and outputs need to be balanced.

Rain adds water to a catchment, so precipitation is an input.

On the other hand, surface runoff, evaporation and transpiration
decrease the amount of water in a catchment, so these processes
are outputs. These processes can be represented in a water
budget equation as shown below.

Input Output
Net =
change in storage
Precipitation - Surface runoff, evaporation, transpiration

output.
Water surplus occurs when input is more than
outp ut.
er e i occurs when input is less than

Since the amounts of inputs and outputs change throughout the

year, the amount of water stored within a catchment changes as
well. This is known as net change.

Questions for understanding

Based on the weather you are experiencing

now, do you think Singapore’s catchment
area is experiencing water surplus or water
deficit What makes you say so

SecGeoEX/NA_Course1_Ch3_PFPB.indd 66 7/7/20 11:33 AM

 67

To learn more about

this chapter, check
out this lesson on the
Singapore Student
Learning Space.
go.gov.sg/lsg006

Questions for reflection:

How does a water surplus or

water deficit affect your daily life

Why is it important to understand

the concept of water budget?

SecGeoEX/NA_Course1_Ch3_PFPB.indd 67 7/7/20 11:33 AM

 Thirsty for Water
Let‛s go to
68

It is the year 2061.

ow Look That‛s a
This is so cool high tech water cooler

Haha! Stop it!

Take that!

ay!
! Mayd
Mayday t alert!
n
Polluta

SecGeoEX/NA_Course1_Ch3_PFPB.indd 68 7/7/20 11:33 AM

 Let‛s turn on the
pestici e sprinkler an
69
ay! increase the amount
! Mayd
Mayday t alert!
n
Polluta

Oooh, no! ou are all arreste

hat problems will we ace i we

continue to use our water without
thinking about its impact on the
en ironment an others How can
you help to sol e these problems

SecGeoEX/NA_Course1_Ch3_PFPB.indd 69 7/7/20 11:33 AM

 CHAPTER GLOSSARY
70
Bedrock Solid rock in the ground that holds up the loose soil above

A catchment refers to an area receiving water, and also contributes water

Catchment to rivers

Condensation The process of changing from a gaseous state to a liquid state

Distribution The way in which people or things are spread out in a place

Evaporation The process of changing from a liquid state to a gaseous state

Flow The movement of water in various ways and mediums

Freshwater Water that has very little amount of salt

Gaseous A state that water exists in, in which its molecules are spaced far apart

Glacier A large mass of ice that moves slowly

Groundwater Water that collects below the surface of the Earth

Groundwater flow Very slow movement of water below Earth’s surface

The sequence of processes through which water passes from water

vapour in the atmosphere through precipitation on land or water
Hydrological cycle surfaces and ultimately back into the atmosphere as a result of
evaporation and transpiration

Infiltration The process in which water enters the ground or soil

Input When water enters a catchment area

A large area of water surrounded by land and not connected to the sea
Lake except by rivers or streams

A state that water exists in, in which its molecules are spaced more
Liquid closely than in the gaseous state, but are not placed in a fixed structure
as in the solid state

Natural process A series of changes that happens naturally

SecGeoEX/NA_Course1_Ch3_PFPB.indd 70 7/7/20 11:33 AM

 Net change The difference between the input and output of a system

A large mass of water that is connected to other similiar masses

Ocean of water

71
Output When water leaves a catchment area

Downward flow of water through soil into the groundwater due to

Percolation gravity

Physical state One of the conditions in which matter exists

Pore A very small hole on the surface of plants or rocks

Water that falls from the clouds towards the ground, especially as rain
Precipitation or snow

River A natural, wide flow of freshwater across land

River mouth The place where the river enters the ocean

River source The place where the river begins

Soil The loose topmost layer of Earth’s surface where plants grow

Soil moisture Water that is stored in the pores of the soil

A state that water exists in, in which molecules are arranged in a fixed,
Solid orderly manner and are closely spaced

Store/Storage A place where water is contained

Water that travels over the surface of the ground to reach streams and
Surface runoff rivers

Transpiration The process by which water is lost through the surface of a plant

When output is more than input, more water is lost than received and
Water deficit a catchment is likely to have less than enough water available

When input is more than output, more water is received than lost and
Water surplus a catchment is likely to have more than enough water available

SecGeoEX/NA_Course1_Ch3_PFPB.indd 71 7/7/20 11:33 AM

 CHAPTER

SUSTAIN
72

MANAGEMEN
Learning
Outcomes
In this chapter, we will learn to:
• describe how the availability of
water changes due to variations
in precipitation;
• describe how water supports
river ecosystems;
• describe how water is used by
people;
• explain how human actions
have led to water pollution
and its associated impact;
• explain the strategies taken
to sustainably manage water
resources in Singapore and
other countries; and
• evaluate the strategies taken
to sustainably manage water
resources in Singapore and
other countries.
(OPTIONAL FOR NORMAL
(ACADEMIC) STUDENTS)

A photograph showing the

Marina Barrage, Singapore

SecGeoEX_NA_Course1_Ch4_3rdpf.indd 72 06/07/20 7:47 PM

AINABLE
ENT OF WATER

SecGeoEX_NA_Course1_Ch4_3rdpf.indd 73 06/07/20 7:47 PM

 74
Water

What Relationship Does Water Have

With the Environment and People?

How Do Variations In How Does Water How Do People

Precipitation Affect The Support River Use Water?
Availability Of Water? Ecosystems?

• Floods • Domestic
• Droughts • Recreation
• Agriculture
• Industry

SecGeoEX_NA_Course1_Ch4_3rdpf.indd 74 06/07/20 7:47 PM

 75

How Can Water Be

Managed Sustainably?

How Do Human • Improve water quality

• Reduce water consumption
Actions Lead to Water • Improve water technologies
Pollution and Its • Import water
Associated Impact?

SecGeoEX_NA_Course1_Ch4_3rdpf.indd 75 06/07/20 7:47 PM

 ONE
How Do Variations in
76
Precipitation Affect the
Availability of Water?
The amount of precipitation that an area receives will determine how much water
is available. This may result in:

• floods • droughts

Figure 4.1 A photograph showing the flash floods experienced in the Philippines due to
heavy rainfall from Typhoon Tembin in December 2017

Figure 4.2 A photograph showing a drought in California, USA, from 2012 to 2016

SecGeoEX_NA_Course1_Ch4_3rdpf.indd 76 06/07/20 7:47 PM

 WHAT ARE FLOODS?
A floo is an overflow of a large amount of water onto what is
normally dry land. Flash floods and river floods are two common
types of flood.

Flash floods are caused by exceptionally heavy rainfall over a short

oo period of time. These floods often occur in dry areas where there is 77
not enough soil or vegetation to allow rainwater to infiltrate
the ground. Therefore, most of the rainwater that falls
onto the ground becomes surface runoff which
quickly floods low-lying areas.
An area receives a lot
1 of rain over a sustained
period of time.
River floods are typically caused by
sustained heavy rainfall, or
meltwater produced when
snow and ice start to melt in
spring. The large amounts
A large amount of of rainwater and meltwater
2 water enters the river. enter streams and
tributaries, which then flow
into rivers. The water level
in the rivers rises rapidly
and it eventually overflows
the banks, flooding the
surrounding areas.

The water level in the

3 river rises quickly and the
river overflows its banks.
Drought Figure 4.3 A diagram showing how
river floods are caused by
An area receives very excessive rainfall
1 little rain over a long
period of time.

There is too little rainwater

2 to replenish the river.

The water level in the

3 river drops gradually, until
it eventually runs dry. Figure 4.4 A diagram showing how
droughts are caused by
lack of rainfall over a
prolonged period of time

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 WHAT ARE DROUGHTS?
A rou is a long period of little or no rainfall in a specific area. Droughts may
last for months or even years, causing areas to become drier than normal. There
may not be enough water available to replenish the amount used for human
activities or lost through evaporation and transpiration. As a result, water stores
such as reservoirs and groundwater will start to dry up.
78

Questions for understanding

The photographs below are taken in the same country. Why is it possible for floods and droughts to
occur in the same country?

Figure 4.5 A photograph showing people watching the rescue process in a flooded area

Figure 4.6 A photograph showing a farmer pointing to a drought-affected land

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 TWO
How Does Water Support
River Ecosystems? 79

Precipitation provides a regular supply of water to rivers so that organisms can live in it.
In other words, water supports the river ecosystem, which refers to the community of
plants and animals found in rivers that interact with one another.

A food chain shows the relationships among organisms as energy is transferred through
food. Predators gain the energy they need to survive by eating their prey.

At the bottom of the food chain are aquatic plants known as phytoplankton. They
obtain energy from sunlight through photosynthesis and release oxygen into the water.
Zooplankton, or small aquatic animals, feed on phytoplankton. Insects feed on
zooplankton and in turn, the insects are eaten by fish. Humans are at the top of the
food chain.

sunlight

human

phytoplankton
large fish
zooplankton

small fish

aquatic insects

Figure 4.7 A diagram showing

an aquatic ecosystem

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 THREE
How Do People Use Water?
80 domestic
11%
People use water for the following purposes:
19%
• domestic • recreation industry
70%
• agriculture • industry
agriculture

Figure 4.8 How water was used globally in 2016

HOW IS WATER
according to the Food and Agriculture
Organisation of the United Nations

USED FOR DOMESTIC PURPOSES?

Using water for household activities is known as omes i
use of water. In Singapore, water used in the shower,
in the kitchen and for flushing, account for the highest Questions for reflection
percentages of water used domestically. In 2017, each
Singaporean consumed an average of 143 litres of water How much water do you use? Calculate
per day for domestic activities. PUB, Singapore’s National your water footprint using this online
Water Agency, hopes to lower this amount to 130 litres of calculator: https://www.watercalculator.org/.
water per day by 2030.

HOW IS WATER USED FOR RECREATION?

Water also enables people to carry out certain recreational activities. This is known as recreational
use of water. Water sports such as canoeing, sailing and sport fishing are highly dependent on water
conditions as well as water quality.

Figure 4.9 A photograph showing canoeists at the Figure 4.10 A photograph showing a man fishing at
Kallang Water Sports Centre, Singapore Lower Peirce Reservoir, Singapore

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 HOW IS WATER USED
FOR AGRICULTURE?
Agriculture accounts for the largest use of water worldwide. Water is used to grow crops and
rear animals for human consumption. Different animal and plant products require different
amounts of water. For example, among plant products, the production of nuts requires more 81
water than the production of vegetables or fruits. Among animal products, the production of beef
requires a much higher amount of water compared to the production of chicken and pork.

ro u i re s o w er use per i o r m pro u e

Beef 15,414
Nuts 9,063
Goat meat/Mutton 8,763

Pork 5,988

Butter 5,553

Chicken 4,325

Pulses (e.g. chickpea) 4,055

Eggs 3,265

Oil crops (e.g. soybean) 2,364

Cereals (e.g. rice) 1,644
Milk 1,020
Fruits 962
Starchy roots (e.g. potato) 387

Vegetables 322

Sugar crops (e.g. sugar cane) 197

Figure 4.11 A graph showing the amount of water used to produce different plant and animal products in
2010 according to the UNESCO-IHE Institute for Water Education

To learn more about

this chapter, check
out this lesson on the
Singapore Student
Learning Space.
go.gov.sg/lsg007

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 HOW IS WATER USED
82 FOR INDUSTRY?
Many in us ries require water to function. Water is used to cool equipment
in factories and power plants because they generate a lot of heat when they
operate. Water is also used to generate electricity when it passes through
turbines installed in dams.

power house
power transmission cables transformer

dam

storage reservoir
storage reservoir

Figure 4.12 A diagram showing how hydroelectricity

is generated

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 In addition, water is used as a cleaning agent in wafer fabrication, which
is the process of creating components for the electrical circuitry found
in computers and mobile phones.

Geo-Fact
83
Did you know that
some of the world’s
largest wafer fabrication
companies like Intel and
Micron operate factories
in Singapore, where
NEWater is used in the
manufacturing process?
This is because NEWater
contains very few
impurities.

Figure 4.13 A photograph showing a loading robot in a

wafer fabrication semiconductor plant

Geo-Fact

Did you know that

the water quality of
generator Singapore’s reservoirs
is monitored every
day? The Smart Water
Assessment Network
(SWAN) consists of
robotic swans which are
actually water quality
monitoring devices.
They are used by PUB to
collect water quality data
in real time.

Figure 4.14 A photograph showing a SWAN

turbine
robot monitoring water quality in
Marina Reservoir, Singapore

downstream outlet

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 FOUR
How Do Human Actions
84
Lead to Water Pollution
and Its Associated Impact?
Human activities often cause water pollution for various reasons. Some people
may conveniently throw rubbish into drains, and factories may release toxic
chemicals in the sea to save costs. Some countries may not have proper systems
to treat wastewater, while others may have accumulated so much waste that their
landfills have started to leak.

Water pollution occurs when harmful substances enter water bodies and cause
water quality to fall. The amount of water that is clean enough to use is thus
reduced. One third of rivers in Africa and Asia are already affected by water
pollution, even though they are a source of water for millions of people.

Water pollution poses a threat to aquatic ecosystems. Pollutants like pesticides

and lead kill plants and poison animals that feed on them. Besides, excess
fertilisers from farms that get washed into rivers by rain provide additional
nutrients for algae to grow rapidly. When the algae eventually die, they are
decomposed by bacteria, which take in oxygen during the process. As a result,
less oxygen remains in the water, causing fish and other aquatic animals to die.

Figure 4.15 A photograph showing dead fish lying on the shores of the Ypacarai Lake,
Paraguay, due to pollution in its waters

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 The Rhine is the most important river in Western Europe. It originates in
Switzerland and flows through Germany, France and the Netherlands before
entering the North Sea. The river had been seriously polluted since the 1950s.
A toxic chemical spill in 1986 worsened the situation, when large amounts of
pesticides were released into the river. Many fish died and some species
went extinct.

After this disaster, the governments of Switzerland, Germany and France 85

decided to work together to manage pollution in the Rhine. Monitoring
stations were installed along the river, enabling water quality to be measured
continuously every six minutes. Industries found responsible for polluting the
river were also fined. Since then, water quality in the Rhine has seen
significant improvement.

owres

Figure 4.16 A photograph showing dead eel that had to be collected

from the Rhine after the 1986 chemical spill disaster

To learn more about

this chapter, check
out this lesson on the
Singapore Student
Learning Space.
go.gov.sg/lsg008

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 FIVE
How Can Water
86
Be Managed
Sustainably?
Given the limited amount of clean freshwater available on the earth, countries
around the world have attempted to manage their water resources by:

• improving water quality • reducing water consumption

• improving water technologies • importing water

These management strategies help to ensure that there is an adequate

supply of water for human activities in both the short term as well as in the
long term.

HOW DO COUNTRIES IMPROVE

WATER QUALITY?
Water quality is determined by considering factors like temperature, amount
of dissolved oxygen, turbidity and pH. These factors affect how well aquatic
plants can grow, as well as the range of aquatic animals that can survive.
Countries often implement laws to maintain or improve water quality.

For example, under Singapore’s Environmental Protection and Management

(Trade Effluent) Regulations, industries are not allowed to release wastewater
into water bodies without permission from the National Environment Agency
(NEA).

WASTEWATER RELEASED BY INDUSTRIES INTO

WATER BODIES CANNOT CONTAIN:
pesticides, fungicides,
herbicides, insecticides, radioactive material
rodenticides or fumigants

refuse, garbage, sawdust,

petroleum or other
timber, human or animal
inflammable solvents
waste or solid matter

Figure 4.17 A diagram showing pollutants that are banned from wastewater

SecGeoEX_NA_Course1_Ch4_3rdpf.indd 86 06/07/20 7:48 PM

 Questions for
understanding

How would you

rate the water
quality in the
water body
shown? How do
you think the
water quality has
been managed?

Figure 4.18 A photograph showing Upper Seletar Reservoir, Singapore

In order to cope with water shortages, China has aimed to clean up polluted rivers so
that more clean water is available for agriculture and industry.

In January 2018, the government implemented a revised version of the Water Pollution
Prevention and Control Law. Officials who achieve the clean water standards are
rewarded, while those who do not meet the standards face fines and loss of promotion
opportunities. The new law also requires cities with only one water source to set up
emergency and back-up water resources.

Figure 4.19 A photograph of debris and garbage polluting the Xixiang River in Shenzhen,
China

SecGeoEX_NA_Course1_Ch4_3rdpf.indd 87 06/07/20 7:48 PM

 HOW DO COUNTRIES REDUCE
WATER CONSUMPTION?
The amount of water used is known as water consumption. Water consumption tends
to increase as a country’s population grows, since more water is needed to grow food
and manufacture goods for people. Although water is a renewable resource, it can
88
run out if it is used faster than it can be replenished naturally. This is why countries try
to reduce water consumption by encouraging people to conserve water.

Since 2007, PUB has presented Watermark Awards to organisations which have
introduced water conservation strategies. Some of these strategies include placing
message cards to encourage hotel guests to reuse towels instead of sending them to
the laundry every day, as well as getting students to track their household water bills.
PUB also encourages people to save water through social media platforms.

Pending permission from copyright owner

owres

Figure 4.20 A social media post showing a water conservation message from PUB

SecGeoEX_NA_Course1_Ch4_3rdpf.indd 88 06/07/20 7:48 PM

 South Africa is a popular tourist destination known for its safari parks and
scenic landscapes. However, the country’s dry climate makes it prone to
droughts. This has led businesses to introduce new practices to reduce water
consumption while still continuing to attract tourists to the country.

From 2018 to 2019, South Africa experienced a drought. During the drought,
some restaurants started harvesting water from their air-conditioning units
to mop the floor, while certain hotels reused wastewater from showers and 89
basins to flush toilets. Golf clubs were encouraged to grow native plants and
harvest water for irrigation. A tourism marketing campaign with the hashtag
#WaterWiseTourism was even launched to raise awareness of the need to
conserve water among tourists and businesses.

owres

Figure 4.21 A poster showing tourists water conservation strategies

SecGeoEX_NA_Course1_Ch4_3rdpf.indd 89 06/07/20 7:48 PM

 Geo-Fact Did you know that you can reduce
90 the amount of water for brushing
teeth by as much as 24 times
if you use a mug compared to
leaving the tap running? Following
the five simple tips shown below
will help you to save up to 140
litres of water every day!

Pending permission from copyright owner

Part 1
Intake Screening

Sea

Intake
Screens

mechanical
filtration
Figure 4.22 A poster showing five simple water-saving tips

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 HOW DO COUNTRIES
IMPROVE WATER
TECHNOLOGIES?
Countries are increasingly using technology to 91
develop new ways of generating and conserving water.

Although Singapore is an island surrounded by the

sea, seawater cannot be used directly because of
its high salt content. However, Singapore is able
to convert seawater to fresh water for use through
desalination. This process involves lowering the salt
content of seawater to a level that is acceptable for
use by industries and households. Technology allows
desalination to take place quickly and on a large scale.

As of 2020, Singapore has five desalination plants.

The Keppel Marina East Desalination Plant is one
of the world’s first large-scale desalination plants
that can treat both seawater and fresh water in one
place. Desalination is projected to meet up to 30% of
Singapore’s water demand by 2060.

Part 2 Part 3
Pre-treatment Reverse Osmosis
(Ultrafiltration)

Pending permission from copyright owner Fresh

Water

Ultrafiltration Seawater Reverse Low Pressure Reverse

Membranes Osmosis System Osmosis System

Remove
minerals
• impurities
• microorganisms
• bacteria fluoride
reverse
osmosis unit

Pre-treated Seawater
Figure 4.23 A diagram showing how Singapore desalinates water
Fresh Water

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 The USA is one of the top oil-producing countries in the world.
For instance, Kern County, located in the southwestern part of
the USA, produces thousands of barrels of oil every day. However,
in order to produce a single barrel of oil, nearly 400 litres of
wastewater is generated. Kern County has to spend millions of
dollars to treat such wastewater before it can be discharged.

92 Fortunately, the county is experimenting with the use of artificial

intelligence to treat wastewater. A machine first analyses how
polluted the wastewater is, and then suggests the most effective
method to treat it. With this technology, oil producers can recycle
up to 1.6 million litres of water per day while reducing costs.

membranes

Figure 4.24 A photograph showing an artificial intelligence-powered

machine used in the treatment of wastewater

HOW DO COUNTRIES
IMPORT WATER?
In regions where water is relatively scarce, countries are
likely to prioritise the protection of their water resources and
conflicts between countries may arise over the sharing of water
resources. In other parts of the world, however, countries
which have relatively abundant water resources may allow their
neighbours to import water from them.

Questions for reflection

How do you think water will be produced and

saved in the future? Will clean water come
from a robot? Can a machine cut off your
water supply if you use too much water?

SecGeoEX_NA_Course1_Ch4_3rdpf.indd 92 06/07/20 7:48 PM

 To date, only two agreements on Singapore’s import of water from Malaysia remain. These
agreements will expire in 2061. By then, Singapore aims to rely on other management strategies to
ensure that it can produce enough water on its own to meet its people’s needs.

M A L A Y S I A

93
1962
Linggiu
Reservoir
20 km

S a yo
ng R i v
Semangar Sungai Johor
Operated by
agreement
North

er
Singapore’s PUB
J oh
or • Expires in 2061
R iv K ey
er Kota Tinggi
• Singapore can draw 250 million
W ater treatment plant

gallons of water from the Johor

U rb an area

River every day.

• Singapore pays rent at a standard
SINGAPORE rate and 3 sen per 1,000 gallons
of raw water drawn.
• Singapore provides Johor with
treated water every day, up to 2%
of raw water drawn.
• Singapore charges Johor 50 cents
per 1,000 gallons of treated water.

1961
agreement
• Singapore paid an annual rent of 5 ringgit
per acre and 3 sen per 1,000 gallons of raw
water drawn. 1990
agreement
• Singapore provided Johor with treated water
every day, up to 12% of raw water drawn. • Expires in 2061
• Singapore charged Johor 50 cents per • Singapore can draw 250 million
1,000 gallons of treated water. gallons of water from the Johor
River every day.
• Singapore pays rent at a standard
rate and 3 sen per 1,000 gallons
of raw water drawn.
• Singapore provides Johor with
treated water every day, up to 2%
of raw water drawn.
• Singapore will continue to draw
water from the Johor River.

To learn more about

this chapter, check Figure 4.25 A diagram showing water agreements
out this lesson on the between Singapore and Malaysia over
Singapore Student the years
Learning Space. go.gov.sg/lsg009

SecGeoEX_NA_Course1_Ch4_3rdpf.indd 93 06/07/20 7:48 PM

 Kuwait is another country that imports water due to its dry climate. In 2017, a contract was
signed between Serbia and Kuwait for Kuwait to receive three million litres of water.

Kuwait’s groundwater had run dry since the 1970s. On the other hand, Serbia has about
300 mineral springs and 25 factories for water processing, allowing it to deliver quality
mineral water to Kuwait.

94

Figure 4.26 A photograph of the Krupaj Spring in Serbia

Questions for understanding

How would you evaluate the effectiveness of the To learn more about
different strategies to manage water resources this chapter, check
sustainably? Since each strategy has its advantages out this lesson on the
Singapore Student
and disadvantages, you should consider whether each
Learning Space.
strategy:
go.gov.sg/lsg010
• helps to ensure an adequate supply of water in the
short term or in the long term?
• has any social, economic or environmental impacts?
• affects individuals, the community, the country,
the region or the world?

SecGeoEX_NA_Course1_Ch4_3rdpf.indd 94 06/07/20 7:48 PM

 CHAPTER GLOSSARY
The practice of cultivating land for the growing of crops or
Agriculture rearing animals to provide food and other products

Consumption The amount of a particular resource that is used by people 95

(Consume)

Domestic Related to household activities

Drought A long period of little or no rainfall in a specific area

The community of plants and animals that interact with one

Ecosystem another found in an area

An overflow of a large amount of water onto what is normally

Flood dry land

Import To bring in a good or service from another country for sale

Industry The production of goods in factories

Long term A time scale of decades or more

Management (Manage) The practice of handling or controlling things

The introduction of harmful substances into the physical

Pollution (Pollute) environment

The biological, chemical and physical characteristics of

Quality a substance

The amount of liquid precipitation that falls within a particular

Rainfall area during a specific time

Recreation
Activities done for enjoyment during a person’s free time
(Recreational activities)

Short term A time scale of a few years, months or less

Supply The amount of something that is available for people to use

The equipment and machinery that have been developed

Technology using scientific knowledge

Threat A person, object or issue that is likely to cause danger

SecGeoEX_NA_Course1_Ch4_3rdpf.indd 95 06/07/20 7:48 PM

 CHAPTER

96

SPATIAL D
OF TROPICAL RAINF

Learning
Outcomes
In this chapter, we will learn to:
• describe the characteristics
of tropical rainforests and
mangroves;
• describe the distribution
of tropical rainforests and
mangroves;
• describe the conditions
for the growth of tropical
rainforests and mangroves;
• explain the adaptations
of tropical rainforests and
mangroves;
(OPTIONAL FOR NORMAL
(ACADEMIC) STUDENTS) and
• compare the adaptations
between tropical rainforests
and mangroves.
(OPTIONAL FOR NORMAL
(ACADEMIC) STUDENTS)

A photograph showing a living

root bridge in Cherrapunji, India

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DISTRIBUTION
INFORESTS AND MANGROVES

To learn more about

this chapter, check
out this lesson on the
Singapore Student
Learning Space.
go.gov.sg/lsg011

SecGeoEX_NA_Course1_Ch5_3pfB.indd 97 06/07/20 5:23 PM

 Spatial Distribution of Tropical
98

What Is the Tropical Climate?

• High mean annual temperature
• High annual rainfall

Tropical Rainforests

What Are Tropical What Are the How Have

Rainforests and Where Characteristics of Plants in Tropical
Are They Found? Tropical Rainforests? Rainforests
Adapted to Their
Environment?

• Places with tropical climate • Evergreen

• Broad leaves
• Close to the Equator • Large variety of plant
• Waxy leaves
species
• Drip tips
• Vertical structure
• Buttress roots
- Emergent layer
- Canopy layer
- Undergrowth layer

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al Rainforests and Mangroves
99

Mangroves

What Are What Are the How Have Plants

Mangroves Characteristics of in Mangroves
and Where Are Mangroves? Adapted to Their
They Found? Environment?

• Water with higher salinity • Limited variety of • Salt-secreting leaves

• Coastal areas plant species • Salt-excluding roots
• River mouths • Relatively uniform • Aerial roots
• Sheltered environments height - Pencil roots
• Horizontal zonation - Cone roots
- Prop roots
- Knee-bend roots

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 100

Journey into the Wild

The following is a post of a teenager’s excursion into a tropical rainforest.

“It’s a 90-kilometre trek through the forest from here. See you in a few days’ time!” The boatman
grins and waves at us as his tiny wooden boat drifts away from the water’s edge.

After years of living in the big city, the thought of spending our vacation exploring the largest forest in
this part of the world, ust like the famous pioneers of old, excites my friends and me. Now, two flights
and an overnight boat ride later, we are finally about to embark on our adventure.

I turn around to see a towering mass of trees the height of apartment blocks looming above my head.
The air, still and heavy with moisture after a sudden downpour, is filled with the screeching of birds and
insects. Beads of sweat trickle slowly down my back like fat beetles. I feel my boots sink slightly into the
bright, orangey mud beneath me.

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 101

Suddenly, I am not as excited as I had imagined I would be.

“Let’s get going or we’ll never reach the campsite by nightfall!” exclaims my friend enthusiastically as
he signals to us to follow behind. I trudge into the thick vegetation, trying my best to avoid tripping
over the twisted roots spreading across the ground and getting entangled with the vines dangling
from the branches above.

We stop for a much-needed break after several

hours of finding our way through this seemingly To learn more about
endless sea of green. Out of nowhere, a sudden this chapter, check
rustling of leaves and crackling of fallen twigs catch out this lesson on the
our attention. We freeze for a moment. Tigers have Singapore Student
Learning Space.
recently been spotted in this area.
go.gov.sg/lsg011

SecGeoEX_NA_Course1_Ch5_3pfB.indd 101 06/07/20 5:23 PM

 ONE
What Is Natural Vegetation?
102

lowres

temperate
grassland

lowres

Tropic of
Cancer
temperate
deciduous
forest

Equator
lowres

Tropic of Capricorn

mediterranean
SINGAPORE
forest

lowres

tropical
rainforest

Figure 5.1 A world map showing the global distribution of different types
of natural vegetation

2000 km
SecGeoEX_NA_Course1_Ch5_3pfB.indd 102
K ey 06/07/20 5:23 PM
 Questions for understanding
Natural vegetation refers to plant life which covers particular
parts of the world’s land areas and develops without human
Are the types of natural vegetation
interference. Several different types of natural vegetation found in places close to the Equator
exist, but each of them can be found only in certain parts the same or different from those
of the world. This is because the climate of a given location found in places far away from the
determines the type of natural vegetation found there. Equator? Why do you think this is so?
103

tundra

temperate
coniferous forest

desert

tropical
grassland

SecGeoEX_NA_Course1_Ch5_3pfB.indd 103 06/07/20 5:23 PM

 TWO
What Is the Tropical
104
Climate?
Climate refers to the average weather conditions of a place over a long period of time, usually more
than 30 years. The climate experienced by many areas found within the tropics, the part of the world
located in between the Tropic of Cancer and the Tropic of Capricorn, is correspondingly known as
the tropical climate.

Mean Rainfall
350.0 Mean Temperature 35.0

300.0 30.0

Mean Temperature (c˚)

Mean Rainfall (mm)

250.0 25.0

200.0 20.0

150.0 15.0

100.0 10.0

50.0 5.0

0.0 0.0
J F M A M J J A S O N D

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Mean Rainfall (mm) 234.6 112.8 170.3 154.8 171.2 130.7 154.4 148.9 156.5 154.6 258.5 318.6
Mean Temperature (OC) 26.5 27.1 27.5 28.0 28.3 28.3 27.9 27.9 27.6 27.6 27.0 26.4

Figure 5.2 Graphs showing the average monthly rainfall and temperature in Singapore, which experiences
the tropical climate
The tropical climate is also characterised by high annual rainfall of about 2,000
millimetres on average, but can go up to as high as 4,500 millimetres. There is Questions for
rainfall throughout the year. There is no month in which rainfall is very low or understanding
absent. In addition, temperatures are high throughout the year.
What does weather refer
Natural vegetation such as tropical rainforests and mangroves are found in such to? How is it similar to or
a climate type. Mangroves are found along narrow strips of the world’s coasts, different from climate?
and are concentrated largely within the tropics. In fact, approximately
70 per cent of the coastlines in the tropics are covered by mangroves.

SecGeoEX_NA_Course1_Ch5_3pfB.indd 104 06/07/20 5:23 PM

 THREE
What Are Tropical
Rainforests and Where 105

Are They Found?

The tropical rainforest is the main type of natural vegetation found in parts of the world which
experience the tropical climate. Tropical rainforests can be found in Central and South America,
West and Central Africa, as well as South and Southeast Asia. Most of these regions are located
very close to the Equator.

EUROPE N ORT H
ASIA
A M E R IC A
Tropic of
Cancer

AFRICA

Equator

SO U T H
AMER IC A
Tropic of Capricorn
A U S TR A L I A

SINGAPORE

Legend
Tropical rainforests

A N TA R C TI C A

Figure 5.3 A map showing the global distribution of tropical rainforests, which are largely concentrated
within the tropics
2000 km

North
To learn more about
Geo-Fact Did you know that the Amazon this chapter, check
is the largest continuous tropical out this lesson on
rainforest area in the world? It the Singapore
Student Learning
covers an area of about 6 million
Space. go.gov.sg/lsg012
square kilometres and is located in
the northern part of South America.

SecGeoEX_NA_Course1_Ch5_3pfB.indd 105 06/07/20 5:23 PM

 FOUR
What Are the
106 Characteristics of
Tropical Rainforests?
Plants require sunlight and water, among other things, in order to survive and grow.
Areas that experience the tropical climate receive abundant sunlight and high rainfall
throughout the year, making them very suitable for plant growth.

As a result, the vast majority of tropical rainforest plants are evergreen. This means
that they do not shed all of their leaves at particular times of the year. In fact, tropical
rainforest plants continuously grow new leaves to replace older ones that die and
fall off, thus maintaining a constantly green appearance. This is unlike the trees of
temperate deciduous forests in Europe and North America, for example, which shed
their leaves before each winter season to conserve water.

Figure 5.4 A photograph showing a tropical rainforest in Khao Yai National Park, Thailand

SecGeoEX_NA_Course1_Ch5_3pfB.indd 106 06/07/20 5:23 PM

 The suitable climatic conditions also explain why Geo-Fact
tropical rainforests contain a very large variety
of plant species, more than any other type of Did you know that Tampines, one of the first
ecosystem in the world. Furthermore, no particular residential towns set up in Singapore, is named
rainforest plant species is significantly more after the Tempinis tree? This tree grew in
than others. This means that a person can walk abundance in this housing estate in the past.
hundreds of metres inside a tropical rainforest
without finding more than one tree that belongs to
107
the same species.

Tembusu tree Tempinis tree

Tempinis fruit

Tembusu fruit Tembusu flower Tempinis flower

Figure 5.5 Photographs showing common rainforest plants in Singapore

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 The intense competition for sunlight among
tropical rainforest plants causes them to grow
as tall as possible. However, not all plants
can grow to the same height. This gives the
tropical rainforest a distinct vertical forest
structure, comprising three main layers:
• emergent • canopy • undergrowth
108

The tallest trees in the tropical rainforest

are able to grow to 30 metres or more in
height. The crowns of these trees form the
emergent layer.

Most tropical rainforest trees grow to about

20–30 metres in height. Because they grow
very close to one another, their crowns
interlock to form a thick and near-continuous
mass of branches and leaves. This is known as
the canopy layer. It prevents 97–98 per cent
of the sunlight that the top of the tropical
rainforest receives from passing through to
reach the forest floor.

The undergrowth layer is found beneath the

canopy layer. Very little sunlight is able to
reach this layer. Thus, not many plants are able
to grow here, except smaller ones that are
able to grow in the shade and the seedlings of
taller trees.

The amount of vegetation growing near the

ground surface is thus relatively sparse, except
where there are gaps in the canopy, such as
near riverbanks or where a canopy tree has
fallen down.

When gaps in the canopy appear, a lot of

sunlight is able to reach the undergrowth
layer. Certain species of undergrowth plants
are able to take advantage of this situation
by growing upwards very quickly and filling
these gaps.

Geo-Fact

Did you know that although the Amazon

rainforest covers an area only half the size
of Europe, it is home to around 80,000
different plant species, compared to only
20,000 in Europe?

Figure 5.6 A diagram showing the three-layered

vertical structure of tropical rainforests

SecGeoEX_NA_Course1_Ch5_3pfB.indd 108 06/07/20 5:24 PM

 To learn more about
Geo-Fact this chapter, check
out this lesson
Did you know that the large amount of water vapour on the Singapore
released from tropical rainforest trees through Student Learning
Space. go.gov.sg/lsg013
transpiration into the atmosphere contributes to the high
rainfall received?

50 m 109

Emergent layer 40 m

30 m

Canopy layer

20 m

Undergrowth layer
10 m

0m

SecGeoEX_NA_Course1_Ch5_3pfB.indd 109 06/07/20 5:24 PM

 MAL
NOR
A L FO R TS
O P TI
ON U D EN
E M I C) S T
D
(ACA

FIVE
110
How Have Plants in
Tropical Rainforests
Adapted to Their
Environment?
Individual tropical rainforest plants have developed special features or
adaptations in order to cope with the intense competition for sunlight and
high rainfall, including:
• broad leaves • waxy leaves • drip tips • buttress roots

The leaves of most tropical rainforest plants are broad, which means that they
have a large surface area. This enables the plant to absorb as much sunlight as
possible in order to make food for its own survival and growth.

Often, the leaves are also waxy, which gives their surfaces a glossy appearance.
This helps the plant to reduce the amount of water vapour that it loses to the
atmosphere through transpiration as a result of the high temperatures in the
tropical rainforest.

Some tropical rainforest plants have leaves which have small, narrow tips that
point downwards. These drip tips, together with the leaves’ waxy texture,
allow rainwater that falls onto them to flow off easily. Given the frequent heavy
rainfall that occurs in the tropical rainforest, this is important as it helps the
leaves to dry quickly and thus prevents the growth of fungi or bacteria on them.

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 111

Figure 5.7 A photograph showing a

rainforest plant with waxy leaves
that have drip tips

Tropical rainforest trees that grow

to great heights in order to reach
for as much sunlight as possible
usually have buttress roots to keep
them upright and prevent them from
toppling over. While the roots of
most plants are found underground,
buttress roots are special because
they can grow up to five metres
above the ground surface.

Such tropical rainforest trees also

require the support provided by
buttress roots because the rest
of their roots do not extend very
lowres deep beneath the ground surface.
Nutrients are concentrated in the
topmost layer of rainforest soils as
they are released when dead leaves
and branches that have fallen onto
the ground surface decompose.
Tropical rainforest trees thus tend
to have shallow underground roots
so that they can absorb nutrients as
quickly as possible.
Figure 5.8 A photograph showing
buttress roots of
a rainforest tree

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 SIX
What Are Mangroves and
112 Where Are They Found?
Mangrove forests are a unique type of natural
vegetation that is often found along or very
close to the coast. They are made up of a
group of plant species known as mangroves,
which are able to grow in water that has a
higher salinity compared to fresh water.

Although mangrove plants are able to grow in

freshwater areas as well, they grow better in
areas where water salinity is higher due to the
lack of competition from other types of plants EU R O P E
which are unable to grow in such conditions. ASIA

Tropic of
Cancer

AFRICA

Equator

Tropic of Capricorn

SINGAPORE

Legend
M angrov es

Figure 5.9 A photograph showing Figure 5.10 A map showing the global distribution of
mangroves in Thailand mangroves

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 Most of the areas where mangrove forests are located experience the tropical climate. This is
because mangrove plants are unable to withstand freezing conditions, and grow best where
the average air and water temperatures do not fall below 20 °C. They are unable to survive in
places very far north or south of the tropics as a result.
113
Mangrove plants also require calm water conditions so that their seedlings are able to
take root and grow without getting washed away by strong waves. Calm water conditions
encourage the accumulation of fine sediments containing nutrients, which mangrove plants
require to sustain their growth. Hence, mangrove forests are usually found only in sheltered.
environments along or very close to the coast, such as shallow river mouths or behind islands

N O RT H
ASIA AMERICA

SOUTH
AMERICA
AUSTR A L I A

SINGAPORE

AN TA R C T I CA

2000 km

North
SecGeoEX_NA_Course1_Ch5_3pfB.indd 113 06/07/20 5:24 PM
 SEVEN
What Are the
114 Characteristics of
Mangroves?
Like tropical rainforest plants, mangrove plants are also evergreen. However, mangrove forests have a
much lower diversity of plant species compared to tropical rainforests. They are typically dominated
by only a few plant species. For instance, while nearly 1,000 tree species can be found within the small
tropical rainforest in Bukit Timah Nature Reserve, there are only a total of 60–70 mangrove tree species
worldwide. Not many plant species have evolved to survive in waters of higher salinity.

Lower-lying parts of the coast, which are close to the low

1 tide level, are flooded for longer periods of time by the tide
compared to areas which are further inland and closer to
the high tide level. Mangrove plant species that are able to
tolerate higher salinity levels and longer periods of flooding
are thus found closest to the low tide level.

In Southeast Asian mangrove

2 forests, such groups of species
typically include Sonneratia
and Avicennia.

Figure 5.11 A diagram showing the

horizontal zonation of
mangroves
Sonneratia 2 Avicennia

High tide level

1 Low tide level

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 The density of trees in a mangrove forest tends to be
significantly lower than in a tropical rainforest, resulting Questions for understanding
in less competition for sunlight. Because the coastal
environment is difficult for plants to survive in, mangrove Which group of mangrove plant
plants thus need to obtain as much energy from the Sun species is more likely to be able to
as possible. They cannot tolerate shaded conditions, survive in water of higher salinity,
unlike those plants which can survive in the relatively dark Rhizophora or Bruguiera? Why do
undergrowth layer of tropical rainforests. As a result, you say so? 115
mangrove plants are relatively uniform in terms of height.

Nevertheless, some species of mangrove plants are

able to survive in water of higher salinity and withstand
longer periods of flooding by the tide compared to other
species. Because of this, mangrove forests tend to exhibit
a horizontal zonation that is largely determined by the
high and low tide levels. Zonation refers to the distribution
of plants in specific areas according to certain parameters,
each characterised by its dominant species.

On the other hand, other groups of

3 species which are not as tolerant of
these conditions, such as Rhizophora and
Bruguiera, are usually found closer to the
high tide level instead, where the duration
of flooding by the tide is shorter.

Rhizophora Bruguiera
3

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 MAL
NOR
A L FO R TS
O P TI
ON U D EN
E M I C) S T
D
(ACA

EIGHT
116
How Have Plants in
Mangroves Adapted to
Their Environment?
Mangrove plants have developed various adaptations to help them survive in the saline water of the
coastal environment, including:

• salt-secreting leaves • salt-excluding roots • aerial roots

Many living things, including humans,

are unable to survive on salty water.
However, certain groups of
mangrove species, such as Avicennia,
have salt-secreting leaves that
enable them to remove salt from
the saline water that their roots
have absorbed. As the concentrated
salt solution secreted by the leaves
evaporates, salt crystals are left
behind on the leaf surfaces, and are
subsequently removed by rain or
wind.

Other groups of mangrove species

like Sonneratia are unable to secrete
salt through their leaves. Instead,
they deposit excess salt in older
leaves which they eventually shed.
The removal of salt in this manner
helps to prevent salt from building
up within the plant.

Figure 5.12 A photograph showing a mangrove plant

with salt crystals on its leaves

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 There are also some mangrove species which deny the intake of salt content using their roots.
These salt-excluding species take in water through their roots which prevent salt from entering.
An example is the Bruguiera.

The soil found in the coastal environment is flooded The aerial roots of Avicennia and Sonneratia
for several hours of the day by the tide. As a result, grow vertically upwards from the main roots
not only is it waterlogged and very poor in oxygen, that are found just below the soil surface.
it is also soft and unstable. Mangrove plants have 117
developed special types of aerial roots that help The roots of Avicennia are known as pencil
them to adapt to these soil conditions. roots due to their slender appearance.
They can grow up to 20 centimetres tall.
Although the aerial roots of different mangrove plant
species differ from one another in terms of appearance,
they all serve similar functions. Firstly, they all grow
partially above the soil surface, which enables them
to take in oxygen directly from the air when they are
exposed during low tide. This helps them to survive
in the oxygen-poor soil. Secondly, the roots help to
anchor the mangrove plants to the soft soil, thus
preventing them from being uprooted and washed
away by strong waves.

The roots of Sonneratia

are thicker and are known
as cone roots due to
their conical appearance.
They can grow up to
1.5 metres tall.

Rhizophora have curved prop

roots that grow from the trunk and
lower branches toward the ground.
They help the plant breathe and
provide it with support as they
form a broader base around it.

Bruguiera have
knee-bend roots, To learn more about
which bend upwards this chapter, check
to emerge above the out this lesson on the
soil surface before Singapore Student
bending downwards Learning Space.
go.gov.sg/lsg014
into the soil at regular
intervals.

Figure 5.13 Photographs showing the various types of aerial roots of different groups of
mangrove plant species

SecGeoEX_NA_Course1_Ch5_3pfB.indd 117 06/07/20 5:24 PM

 Forest in Peril
Today, we are going on a
118 guided tour of the forest by
one of the indigenous people.

The forest provides us with Wow! I never knew there

many benefits. The plants are so many plants with such
provide us with food and some amazing medicinal properties!
even have medicinal properties. The forest is truly amazing!
We also hunt animals for food.

All of a sudden ...

Hey guys, what‛s

that over there?

G !
A N BANG!
B !
N G
BA

SecGeoEX_NA_Course1_Ch5_3pfB.indd 118 06/07/20 5:24 PM

 Hey! Stop right there!

119

Oh no, it looks
like we‛re too late.

Are you alright? Look, there‛s a

huge fire raging
over there!

Why would anyone

set fire to a place
as beautiful as this?

What can we do
to protect the
rainforests?

How can we use

resources in
rainforests more
sustainably?

SecGeoEX_NA_Course1_Ch5_3pfB.indd 119 06/07/20 5:24 PM

 CHAPTER GLOSSARY
Features that plants have developed through evolution,
Adaptations which make them suited to their environment and help them
to survive
120

Plant roots that for at least part of the day are exposed to the air,
Aerial roots allowing the plant to breathe

Annual rainfall The total amount of rainfall a place receives in a given year

Broad leaves Plant leaves that have a large surface area

Large roots that grow above the ground surface to provide

Buttress roots support to tall trees

The thick and near-continuous layer formed by the tops of

Canopy layer rainforest trees of approximately the same height

The average weather conditions of a place over a long period of

Climate time, usually over 30 years

Coast The boundary between the land and the sea

Thick and conical aerial roots that grow vertically upwards from
Cone roots beneath the soil surface

Diversity The range of different things

The narrow, downward-pointing ends of leaves that allow

Drip tips rainwater to flow off easily

The layer formed by the tops of the tallest trees in the tropical
Emergent layer rainforest that rise above the canopy

An imaginary line on the Earth’s surface that is of equal distance

Equator from the North and South Poles it is defined as latitude 0 and
divides the Earth into the northern and southern hemispheres

Evergreen Producing green leaves throughout the year

Forest structure The vertical or horizontal arrangement of plants in a forest

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 Aerial roots that bend upwards to emerge above the surface
Knee-bend roots before bending downwards into the soil at regular intervals

A group of plant species that are able to grow in water that has a
Mangroves higher concentration of salt compared to freshwater

Mean annual
The average of the mean monthly temperatures in a given year 121
temperature
Plant life that covers particular parts of the world’s land
Natural vegetation areas and develops without human interference

Slender aerial roots that grow vertically upwards from beneath

Pencil roots the soil surface

Curved aerial roots that grow from the trunk and lower branches
Prop roots towards the ground

Salinity The amount of salt dissolved in water

Salt-excluding Types of mangroves where water is taken up by the roots and salt
species is excluded

Salt-secreting
Leaves that are capable of expelling excess salt from a plant
leaves
Organic or inorganic particles, typically mud and sand, that are
Sediments deposited by natural processes

Sheltered Coastal locations that are protected from strong waves and
environments currents

The rising and falling of the sea level that usually occurs twice a
Tide day due to the gravitational pull of the Moon and Sun

An imaginary line on the Earth’s surface that is 23.5°

Tropic of Cancer north of the Equator (i.e. latitude 23.5°N)

An imaginary line on the Earth’s surface that is 23.5°

Tropic of Capricorn south of the Equator (i.e. latitude 23.5°S)

Tropical climate The climate that many areas located within the Tropics experience

A type of natural vegetation found in many areas that experience

Tropical rainforest the tropical climate

The bottom-most layer of the tropical rainforest comprising small

Undergrowth layer shrubs and seedlings of taller trees

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 Plant leaves with a glossy texture that reduces the amount of water
Waxy leaves vapour lost through transpiration and enables rainwater to flow off
easily

The distribution of plants into specific zones, each of which is

Zonation characterised by a dominant plant species

122

NOTES

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 123

SecGeoEX_NA_Course1_Ch5_3pfB.indd 123 06/07/20 5:24 PM

 CHAPTER

SUSTAINABLE
124

OF TROPICAL RAINF

Learning
Outcomes
In this chapter, we will learn to
describe the environmental
functions of tropical rainforests
and mangroves
describe how tropical
rainforests and mangroves are
used by people
describe the impact of
extracting resources from
tropical rainforests and
mangroves on the physical
environment
explain the strategies taken to
sustainably manage tropical
rainforests and mangroves in
Singapore and other countries
and
• evaluate the strategies taken
to sustainably manage tropical
rainforests and mangroves in
Singapore and other countries.
(OPTIONAL FOR NORMAL
(ACADEMIC) STUDENTS)

A photograph showing a
mangrove restoration pro ect in
Southeast Asia

SecGeoEX_NA_Course1_Ch6_3pfB.indd 124 06/07/20 5:26 PM

BLE MANAGEMENT
INFORESTS AND MANGROVES

SecGeoEX_NA_Course1_Ch6_3pfB.indd 125 06/07/20 5:26 PM

 Sustainable Management of
126

What Relationships Do Tropical Forests

What Are the How Are

Environmental Tropical Forests
Functions of Used by People
Tropical Forests

Generate oxygen Place of habitation

Contribute to carbon storage Place for recreation
Provide habitats for diverse Source of food
animal life Source of raw materials
Provide protection from soil
erosion
Provide protection from
coastal erosion

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 Tropical Rainforests and Mangroves
127

Have With the Environment and People?

What Are the How Can

Consequences Tropical Forests
of Extracting e Managed
Resources From Sustainably
Tropical Forests

Deforestation Establish protected areas

• Enhanced Promote public education
greenhouse effect Regulate forestry activities
• Rehabilitate disturbed areas

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 ONE
What Are the
128
Environmental Functions
of Tropical Forests?
Tropical forests, which comprise tropical rainforests Geo-Fact Did you know that although
and mangroves, are important to the physical tropical rainforests cover less
environment because they perform the following than 10 of the earth’s land
functions surface at present, they are
actually responsible for producing
• generate oxygen
as much as 0 of all the oxygen in
the atmosphere
contribute to carbon storage

provide habitats for diverse animal life

provide protection from soil erosion

provide protection from coastal erosion food for sunlight

animals

HOW DO TROPICAL
FORESTS GENERATE
OXYGEN? oxygen carbon dioxide
Tropical forests support the survival of many
organisms in the physical environment because of
their ability to generate oxygen. Rainforest and
mangrove plants carry out oxygen generation
through photosynthesis, the process in which
they absorb carbon dioxide, water and sunlight to
produce food for their own survival and growth.
Furthermore, they are capable of producing oxygen
throughout the year as they are evergreen.

nutrients
Figure 6.1 A diagram showing how trees water
generate oxygen

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 HOW DO TROPICAL FORESTS
CONTRIBUTE TO CARBON STORAGE?
Rainforest and mangrove plants contribute to carbon storage when they absorb carbon
dioxide from the atmosphere during photosynthesis. This helps to balance the amount of
carbon dioxide being added to the atmosphere through natural processes like respiration
129
and decomposition.

Carbon dioxide in the

atmosphere is absorbed
through photosynthesis.

Dead leaves and branches that

The absorbed carbon dioxide fall to the ground add carbon
is stored in solid form in to the soil.
the plants — in their leaves,
branches, stems and roots.

The roots of the plants also produce soil carbon.

Figure 6.2 A diagram showing how trees contribute to carbon storage

Among the different types of natural vegetation, mangroves are one of the
most effective at storing carbon. It is estimated that on average, they store about
0 0 kilogrammes of carbon per square kilometre every year. This is significantly
higher than tropical rainforests, which store about 20 kilogrammes of carbon
per square kilometre every year.

As the soil in mangroves

is waterlogged and poor in Questions for understanding
oxygen, there are few bacteria
available to break down the If there were no tropical forests to store carbon, what do you think
carbon stored there. This would happen to the earth What makes you say so
is why mangroves are so
effective at storing carbon.

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 HOW ARE TROPICAL FORESTS
HABITATS FOR DIVERSE ANIMAL LIFE?
Tropical forests are rich in biodiversity. Their warm climate and the abundance of water and
food sources all year round make them very suitable habitats for a wide variety of animals.
130
Tropical rainforests

In the Amazon rainforest alone:

There are Over Scientists believe that

300 over 2 million

more than
types
1,000 of mammals, reptiles
species of insects may also be found.

species of freshwater and amphibians have Only a small fraction of these has
fish and birds. been discovered to date. ever been collected and named.

Malayan tapir

poison dart frog

blue-throated toucanet

piranha

Yacare caiman

Figure 6.3 Photographs showing examples of animals found in tropical rainforests

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 Mangroves
The dead leaves and branches that fall from mangrove egret
plants are broken down by bacteria into tiny particles
which fishes, shrimps and crabs feed on. These smaller
animals are in turn eaten by larger predators such as
otters, crocodiles and even tigers, which can be found in
the mangrove forests of angladesh and India. 131

Mangroves also serve as breeding grounds for young

fish, as their dense root networks provide shelter from
larger predators. The branches of mangroves also
provide nesting sites for many species of birds, such as
pelicans, herons, egrets and spoonbills.

er r b

heron
pelican

mudskipper

snapper
otter

Figure 6.4 Photographs showing examples of animals found in mangrovess

SecGeoEX_NA_Course1_Ch6_3pfB.indd 131 06/07/20 5:27 PM

 HOW DO TROPICAL RAINFORESTS
HELP PREVENT SOIL EROSION?
Tropical areas regularly experience heavy rainfall, which is likely to cause soil erosion.
Rainforest plants can help to prevent this from happening as they provide a protective
covering over the ground surface.
132

Falling raindrops
1 hit the soil with
considerable force,
causing soil particles
to become detached.

The loosened soil particles are easily

3 washed away by flowing water,
resulting in severe soil erosion.

There is little infiltration and

2 percolation of rainwater
into the soil, leading to high
surface runoff.

Figure 6.5 A diagram showing how soil erosion occurs when protective cover is not present

HOW DO MANGROVES HELP

PREVENT COASTAL EROSION?
Mangroves play an important role in protecting coastal areas from erosion as they help to
reduce the power of strong waves and storms.

Loose sediments are

1 easily washed away by 2 Strong waves do not lose
much energy as they
waves, currents and tides. travel towards the coast.

Significant coastal erosion

3 occurs when waves hit
the coast with force.

Figure 6.6 A diagram showing how coastal erosion occurs without mangrove protection

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 Questions for understanding

Do soil erosion and coastal erosion affect humans

What makes you say so

133
The leaves, branches and
1 stems of rainforest plants slow
down falling raindrops before
they reach the ground.

Raindrops hit
3 the soil with
less force.

The overall
5 soil erosion by
flowing water
is minimised.

The roots of rainforest More rainwater can

4 plants also bind the 2 infiltrate and percolate
soil together, making into the soil, thus
it harder to erode. reducing surface runoff.

The dense root

1 systems of
mangrove plants
help to trap and
stabilise loose
The waves lose a sediments on
4 significant amount of the coast.
energy, thus reducing
coastal erosion.
Sediments are
The roots, trunks and 2 less likely to be
3 branches of mangrove washed away by
plants cause friction with waves, currents
waves hitting the coast. and tides.

SecGeoEX_NA_Course1_Ch6_3pfB.indd 133 06/07/20 5:27 PM

 TWO
How Are
134
Tropical Forests
Used by People?
Tropical forests are useful to people because they provide a

place for habitation place for recreation

source of food source of raw materials

HOW ARE TROPICAL Figure 6.8 A photograph showing

orowai tribespeople

FORESTS USED
making use of material
found in the forest

FOR HABITATION?
Although many people today live in towns and cities,
there are still several million people around the world
who continue to live in tropical forests. Many of them are
considered the original inhabitants of the areas where
they live, which is why they are often known as indigenous
people. They depend on the physical environment to meet
their basic needs, such as food, water, shelter and clothing.

Figure 6.7 A photograph showing the dwellings of the

Figure 6.9 A photograph showing a
orowai tribe in New Guinea, Indonesia
Moken person fishing along
the coasts of mangrove
forests in Thailand

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 The orowai tribe, which lives on the island of New Guinea in Indonesia, is an example of people who
inhabit tropical rainforests.

135
Papua
Korowai tribe

200 km

I N D O N E S I A
1 , 000 km New Guinea

North

Figure 6.10 A map showing the region of New Guinea where the orowai tribespeople inhabit

The Moken people inhabit the mangroves along the coasts of southern Myanmar and Thailand.
They hunt for fish in the mangroves as a source of food they also trade fish for rice and other basic necessities.
Mangroves also provide the Moken people with construction material to build the traditional houseboats or
temporary huts which they live in.

5 00 km

North

MYANM AR

THAILAND

Bay of Gulf of
Martaban
Bengal
Andaman
Sea

Moken people

200 km

Figure 6.11 A map showing the region in Asia where the Moken people inhabit

SecGeoEX_NA_Course1_Ch6_3pfB.indd 135 06/07/20 5:27 PM

 HOW ARE TROPICAL
FORESTS USED FOR
RECREATION?
136
Tropical forests are recreational sites for people who live in
towns and cities to get close to nature. Trekking, camping
and birdwatching are some common activities that people
take part in while visiting tropical forests.

Researchers have found that visiting forests has been found

to have a positive effect on people’s health. The natural
sights, smells and sounds of the forest have a calming
effect on people, which helps to give them a sense of
well-being. isiting forests for recreation is also a way for
people to exercise and to lead an active lifestyle.

Figure 6.12 A photograph showing tourists on an elevated

wooden bridge over a tropical forest canopy in
Phuket, Thailand

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 HOW DO TROPICAL FORESTS
PROVIDE A SOURCE OF FOOD?
Many common types of food come from plants that grow in tropical forests.
Examples of these include fruits like bananas and mangoes, vegetables like
cucumbers and eggplants, nuts like razil nuts and cashew nuts, as well as
137
spices like pepper and cinnamon. Some popular desserts are made using
ingredients from tropical forest plants, such as the nipah palm, whose seeds
are found in ice kacang, and the cacao tree, whose seeds are used to make
chocolate.

mangoes

nipah palm seeds

eggplants in ice kacang
cashew nuts

bananas

cocoa pod and beans

cinnamon sticks and powder

Figure 6.13 Photographs showing common types

of food that originate from tropical
rainforests and mangroves

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 Apart from harvesting many different types of edible plants from the tropical forests where
they live, indigenous people also often hunt wild animals such as fish, deer and wild birds
for food. This manner of obtaining food for survival is known as hunting and gathering.

138

Figure 6.14 Photographs showing Mentawi tribesmen hunting and cooking in West Sumatra, Indonesia

In more developed societies, hunting and gathering is not able to provide sufficient food to feed large
numbers of people. This is why mangroves in some coastal areas have been converted into farms that
rear fish, as well as shellfish like prawns and clams, for sale to customers in towns and cities. This is known
as aquaculture.

Figure 6.15 A photograph showing an oyster farm in the mangroves of Chanthaburi, Thailand

SecGeoEX_NA_Course1_Ch6_3pfB.indd 138 06/07/20 5:27 PM

 HOW DO
TROPICAL ebony

FORESTS
PROVIDE 139

A SOURCE
OF RAW
MATERIALS? mahogany

Tropical forests are best

known for being valuable
sources of wood for
building or carpentry.
The wood of certain types of
rainforest trees, such as teak,
mahogany and rosewood,
are particularly valued for
their strength, durability and
colour. Many different kinds
of products are made from rosewood
them, including flooring,
doors, furniture and even
musical instruments.

Wood obtained from

mangrove trees is used
to build houses, etties
and boats. It is also used
directly as fuelwood or
turned into charcoal for
cooking and heating.
In Indonesia and Malaysia,
mangrove trees are cut
down to produce paper
products. teak

Figure 6.16 A diagram showing different types of

tropical hardwoods

SecGeoEX_NA_Course1_Ch6_3pfB.indd 139 06/07/20 5:27 PM

 In some parts of the world, metals and minerals, such as iron and diamonds, can be found
in the ground beneath tropical rainforests. These raw materials are very valuable because
they can be used to make a wide variety of products, such as copper for pipes or gold for
computer microchips.

The process through which metals and minerals are obtained from below ground is known
as mining. The tropical rainforest is first cleared completely by burning or bulldozing.
140 Heavy machinery is then used to dig into the ground to extract these raw materials.

Figure 6.17 A photograph showing a tropical rainforest area that was cleared for coal mining in
East alimantan, Indonesia

Geo-Fact

Did you know that the

Cara s mine, which is located To learn more about this
in northern razil, is one of chapter, check out this
the world’s largest mines lesson on the Singapore
It is estimated to contain Student Learning Space.
approximately 1 billion tons
go.gov.sg/lsg015
of iron ore, as well as gold,
manganese, copper and nickel.
Parts of the Amazon rainforest
were cleared to establish it.

SecGeoEX_NA_Course1_Ch6_3pfB.indd 140 06/07/20 5:27 PM

 THREE
What Are the
Consequences of 141

Extracting Resources
From Tropical Forests?
The resources provided by tropical forests, such as wood and
oxygen, are often considered renewable resources as they are
replenished when the trees and plants grow back. However,
cutting down tropical forests faster than they are able to regrow
risks making these resources non-renewable. Such unsustainable
extraction of resources from tropical forests has two serious
consequences

• deforestation enhanced greenhouse effect

WHAT IS DEFORESTATION?
The permanent removal of tropical forests is known as
deforestation. It may occur due to the unsustainable
cutting down of trees for their wood. Other human
activities like mining, agriculture and aquaculture also
contribute to deforestation as they require very large
areas of tropical forests to be cleared before they can Geo-Fact Did you know that
be carried out. The tropical forest vegetation is prevented the setting up of
from regenerating as the cleared land is converted by oil palm plantations
humans into mines, plantations, ranches or fish farms. across Southeast Asia,
South America and
Even if tropical forest vegetation manages to re-establish Africa has resulted in
itself on a piece of deforested land that people have about 1 ,000 square
abandoned, it will still lack the biodiversity of a tropical kilometres of tropical
forest that has been untouched by humans. Scientists have rainforests being cut
estimated that it may take as long as 1,000 years for the down This is nearly
biodiversity of a re-established tropical forest to reach the equal to the area of
same level as an untouched one. Peninsular Malaysia.

SecGeoEX_NA_Course1_Ch6_3pfB.indd 141 06/07/20 5:27 PM

 The Amazon rainforest in South America contains one third of the earth’s
remaining tropical rainforest. It has lost more than 11 of its original
extent. Deforestation is on the rise in countries like razil, where 0 of methane
the Amazon rainforest is located. If deforestation does not slow down,
up to of the 1 ,000 tree species found in the Amazon rainforest
are likely to face extinction, along with thousands of different species of
CH4
animals that live in the rainforests.
142 Brazil
Indonesia
Sudan
Myanmar
Democratic Republic of Congo
Zambia
Nigeria
Tanzania
Mexico
Zimbabwe
Venezuela
Australia
Bolivia
Philippines
Ecuador
Central & South America
Honduras
Southeast Asia
Paraguay
Africa
Cambodia
Oceania
Argentina
Cameroon
0 50 100 150 200 250 300 350 400 450
Deforested Area (km2)

Figure 6.18 A bar graph showing the loss of tropical rainforest in various
countries from 1 0 200

According to some estimates, over of the world’s mangroves have

already been destroyed due to coastal development and the expansion
of aquaculture. Certain countries in Asia, such as angladesh and the
Philippines, have lost a significant amount of their mangroves.

80,000
1980
2005
70,000
Mangrove forest area (km2)

60,000

50,000
The greenhouse
40,000 4 effect causes the
interior of the
30,000
greenhouse to
20,000 be warmer than
the outside.
10,000

0
Africa Asia North America South America Oceania

Figure 6.19 A bar graph showing the mangrove area in different regions of the
world in 1 0 as compared to 200

SecGeoEX_NA_Course1_Ch6_3pfB.indd 142 06/07/20 5:27 PM

 carbon dioxide
WHAT IS THE ENHANCED
CO2 GREENHOUSE EFFECT?
The earth’s atmosphere behaves in a similar way to a greenhouse.
Certain gases in the atmosphere, such as carbon dioxide, nitrous
oxide and methane, are capable of trapping heat, ust like the 143
glass roof and walls of a greenhouse. This is why they are known
nitrous oxide
as greenhouse gases. Greenhouse gases help to keep the earth’s
surface warm at an average temperature of 1 C. Without them,
N2O the average temperature of the earth’s surface would be much
colder at 1 C.

Figure 6.20 A diagram showing

greenhouse gases

A greenhouse is a glass structure

1 that is used to grow plants in
regulated climatic conditions. Sunlight is able to enter
2 the greenhouse through
its transparent glass roof
and walls, thus warming the
inside of the greenhouse.

Heat inside the

3 greenhouse
cannot
escape to the
surroundings
because the
glass traps it.

Figure 6.21 A diagram showing how the

greenhouse effect occurs

SecGeoEX_NA_Course1_Ch6_3pfB.indd 143 06/07/20 5:27 PM

 Carbon dioxide is one of the most important greenhouse gases found naturally in the earth’s atmosphere.
It is released into the atmosphere when living things respire and decompose. Tropical forest plants help to
prevent the build-up of carbon dioxide in the atmosphere as they absorb this gas during photosynthesis.

Deforestation is believed to be responsible for approximately 20 of the total amount of carbon dioxide
being added to the atmosphere as a result of human activities. This is firstly because the burning or cutting
down of tropical forest plants causes carbon that is stored in the plants and soil to be released as carbon
144 dioxide. Secondly, there are fewer plants left behind to absorb the increased amount of carbon dioxide from
the atmosphere. These lead to the enhanced greenhouse effect.

Figure 6.22 A diagram showing the difference between the natural greenhouse effect (left) and
the enhanced greenhouse effect (right)

Natural greenhouse effect Enhanced greenhouse effect

Sunlight passes through the

1 atmosphere and reaches the
earth’s surface.

Not all of this heat is able

3 to escape into outer space.
Less heat is able to
Some of it is trapped by
greenhouse gases in the
5 escape into outer space.
atmosphere.

CO2
CO2
CO2
CO2
CO2

CO2
CO2

CO2
Mor
in the

CO2
in th
e gre

Greater amounts of
4
ere

carbon dioxide and

Greenhouse gases

e atmo
atmosph

The earth’s surface absorbs

enhous

other greenhouse gases

2 this light energy and warms in the atmosphere trap
up, releasing heat. more heat released by
sphere

the earth’s surface.

e gases

SecGeoEX_NA_Course1_Ch6_3pfB.indd 144 06/07/20 5:27 PM

 In 1880,
carbon dioxide

formed 0.029% of the atmosphere.

Now, it forms over 0.04% of the

145

atmosphere, and continues to increase.

CO2

This has caused the average global 2020

temperature to rise by
0.8 °C since 1880. 1880

If more carbon dioxide continues to be

released into the atmosphere by human
activities such as deforestation, the
average global temperature will rise by a
further 1–4 °C by 2100.

400

Atmospheric Carbon Dioxide Concentration

The temperature
6 of the earth’s 14.8
surface increases. 380
Average Global Temperature (°C)

360
14.5
340
(ppm)
14.2
320
CO2
300
13.9 CO2 concentration
280
CO2
re gr

To learn more
13.6 260
about this chapter,
eenho

check out this 1880 1900 1920 1940 1960 1980 2000
lesson on the Year
Singapore Student
use gases

Learning Space. go.gov.sg/lsg016 Figure 6.23 A graph showing the increase in the amount of
atmospheric carbon dioxide from 1 0-2010. The blue
bars represent the years colder than the global average
temperature and the red bars represent the years
warmer than the global average temperature.

SecGeoEX_NA_Course1_Ch6_3pfB.indd 145 06/07/20 5:27 PM

 FOUR
How Can Tropical Forests
146
Be Managed Sustainably?
Different countries have attempted to manage their tropical forests in a sustainable manner by

establishing regulating rehabilitating promoting

protected areas forestry activities disturbed areas public education

HOW DO COUNTRIES ESTABLISH

PROTECTED AREAS?
A common strategy to conserve remaining tropical forests is to set them aside as protected areas.
Although the level of human activity that is allowed within protected areas varies from country to country,
it is generally very restricted in order to prevent plant and animal life from being negatively affected.

Governments usually put laws in place to ensure that people do not damage these protected areas, such
as by illegally cutting down trees or poaching exotic animals. People who break these laws can be fined
heavily or sent to ail. The effectiveness of establishing protected areas depends on strong enforcement
of these laws, which is sometimes a challenge in less developed countries due to lack of funding.

Figure 6.24 A photograph showing the Nam Ha Figure 6.25 A photograph showing a signboard at
National Protected Area, the first national ukit Timah Nature Reserve in Singapore
park of Laos and an ASEAN national listing regulations for visitors to the park
heritage site

SecGeoEX_NA_Course1_Ch6_3pfB.indd 146 06/07/20 5:28 PM

 Singapore has a total of four protected areas, known as nature reserves, which together cover
an area of nearly square kilometres. They are the ukit Timah and Central Catchment Nature
Reserves, which have been protected since 1 1, as well as the Sungei uloh Wetland Reserve
and Labrador Nature Reserve, which were established in 2002. The law which provides for the
planting, maintenance and conservation of trees and plants within Singapore’s nature reserves is
known as the Parks and Trees Act (200 ).

147

Sungei Buloh Central Catchment

Wetland Reserve Nature Reserve

Bukit Timah Nature Reserve Labrador Nature Reserve

Figure 6.26 A map showing the locations of Singapore’s four nature reserves

SecGeoEX_NA_Course1_Ch6_3pfB.indd 147 06/07/20 5:28 PM

 In other countries, protected areas
may be known as national parks or
biosphere reserves. Some of them
cover very large areas, up to several
times the size of Singapore There are
biosphere reserves spread across
120 countries worldwide.
148
Located in the northern part of Sumatra
island, Indonesia, the Gunung Leuser
iosphere Reserve covers nearly
11,000 square kilometres of tropical
rainforest, which is equivalent to over
1 times Singapore’s land area. It is
home to more than ,000 plant species
and a wide variety of animals such as
orangutans, tigers and elephants.
Figure 6.27 A photograph showing the Gunung Leuser
iosphere Reserve

Gunung Leuser
Biosphere
Reserve

Sumatra
INDIAN
OCEAN

5 00 km

SINGAPORE

I N D O N E S I A

1 000 km

North

Figure 6.28 A map showing the location of Gunung Leuser iosphere Reserve in ukit Lawang, Sumatra, Indonesia

SecGeoEX_NA_Course1_Ch6_3pfB.indd 148 06/07/20 5:28 PM

 HOW DO COUNTRIES REGULATE
FORESTRY ACTIVITIES?
It is often very difficult for a country’s government to set aside all of its remaining
tropical forests as protected areas. This is because of the high economic value of
resource extraction activities, which provide many people with obs and enable the
149
country to earn money from selling the resources overseas. The careful regulation
or control of resource extraction is thus a way to strike a balance between obtaining
economic benefits from tropical forests and conserving them.

Controlled logging is an example of how resource extraction from tropical forests

can be regulated.

Companies are allowed to

1 cut down only older trees 2 The overall amount of
damage to the forest
or a particular species
is reduced as the other
of trees which are
plants are left untouched.
economically
valuable.

This method is
5 practised in countries
such as Malaysia.

The forest is able to

3 recover relatively quickly as
younger trees have more
space and sunlight to grow.

Over a time period of

4 several decades, a forest
can be selectively logged,
given time to regrow, and
then logged once again.

Figure 6.29 A diagram showing the first method

of controlled logging

SecGeoEX_NA_Course1_Ch6_3pfB.indd 149 06/07/20 5:28 PM

 150

Companies are only

1 allowed to cut down small
patches of forest each time.

All the trees and plants in

2 a given patch are cleared.

This method is practised

5 in countries like Colombia.

Patches that have regenerated

4 sufficiently can be logged
again after a number of years.

The patch is small enough

3 to allow the vegetation to
regrow quickly from the
surrounding untouched forest.

Figure 6.30 A diagram showing the second method of controlled logging

SecGeoEX_NA_Course1_Ch6_3pfB.indd 150 06/07/20 5:28 PM

 HOW DO COUNTRIES
REHABILITATE
DISTURBED AREAS?
The diversity of plant and animal species in 151
deforested areas is usually much lower compared
to the original tropical forest. Forest rehabilitation
usually aims to re-introduce at least some of the plant
and animal species which were originally found there.

Reforestation helps to rehabilitate a deforested

area through the planting of new trees. Sometimes,
tree species which are not native to the area may be
planted because they are able to grow more easily
and quickly compared to the original native species.

In Singapore, rehabilitation of mangrove forests

has been carried out on Pulau Semakau, a small
island which was partially converted into an offshore
landfill in 1 . Although
attempts were made to
minimise the deforestation
of natural mangroves
during the construction
of the landfill, about
0.1 square kilometres
of mangrove forest was
cut down eventually.
The Ministry of the
Environment and Water
Resources assisted in
the rehabilitation of the
deforested areas by
replanting a large number
of mangrove seedlings.
Some of these seedlings
managed to survive and
have now grown into a
large and dense mangrove
forest. Similar efforts are
ongoing on Pulau Tekong
and Pulau Ubin.

Figure 6.31 A photograph showing mangrove reforestation efforts in Sungei uloh, Singapore

SecGeoEX_NA_Course1_Ch6_3pfB.indd 151 06/07/20 5:28 PM

 In Trombetas, northern razil, large areas of tropical rainforest that were deforested for mining have been
rehabilitated since the 1 0s. Saplings of different native tree species are grown in a nursery from seeds
that were collected from the surrounding rainforest. These saplings are then replanted in the disused
mining sites. Soil that was removed during mining is also replaced, in order to ensure the survival and
growth of the saplings.

152

Figure 6.32 A nursery in razil with seedlings for reforestation

HOW DO COUNTRIES PROMOTE

PUBLIC EDUCATION?
A lot of the deforestation occurring around the world today is due to people’s
consumption of products made from resources obtained either directly or indirectly
from tropical forests. However, many people are unaware that they depend on
tropical forests for a wide variety of resources, or that they are partly responsible
for deforestation. In Singapore, for example, the products that people buy in
supermarkets may link them to deforestation in other parts of the world, such as
Indonesia or razil.

Public education is, therefore, an important strategy in attempting to reduce

deforestation and to encourage the sustainable extraction of resources from tropical
forests. If people know the importance of tropical forests and understand why
they are under threat, they will be more likely to play a part in helping to reduce
deforestation. For instance, they may decide to buy only wooden products which
have been sourced from sustainably-managed forests, or to recycle waste paper.

SecGeoEX_NA_Course1_Ch6_3pfB.indd 152 06/07/20 5:28 PM

 In Singapore, both the government and non-governmental organisations (NGOs) help to raise
people’s awareness of tropical forests.

The National Parks oard (NParks) regularly organises exhibitions, festivals, talks and workshops
which people can take part in to learn more about tropical forests. It also publishes information
along walking and cycling trails across Singapore, such as the TreeTop Walk in the Central
Catchment Nature Reserve. People who visit these trails are able to en oy and appreciate
Singapore’s tropical forests at their own time and pace. 153

NGOs such as Nature Society (Singapore) organise guided walks and tours to places such as
Pulau Ubin and Mandai mangrove forest. Those who take part are able to find out about the rich
plant and animal life in Singapore’s tropical forests.

Figure 6.33 A photograph showing a group To learn more about

of hikers on a birdwatching trip this chapter, check
in ran i marshes, Singapore out this lesson
on the Singapore
Student Learning
Space. go.gov.sg/lsg017

SecGeoEX_NA_Course1_Ch6_3pfB.indd 153 06/07/20 5:28 PM

 In other parts of the world, tropical forests are popular tourist attractions. They help to attract many
foreign tourists who are interested in wildlife spotting, birdwatching and photography, or who may simply
be curious about the physical environment of the tropics. Local tour guides can help to educate tourists
about the value of tropical forests. Furthermore, the income that is generated from tourism will encourage
governments to conserve the forests so that more tourists will be encouraged to visit.

Nyungwe National Park in Rwanda contains one of Africa’s oldest rainforests. The diverse wildlife found
154 here, such as chimpanzees and baboons, is helping to attract increasing numbers of foreign tourists to
visit the country.

A F R I C A

Figure 6.34 A photograph showing a

tourist visiting Nyungwe
National Park, Rwanda 5 0 km

RWANDA
Nyaungwe
National Park
North

5 00 km

Figure 6.35 A photograph showing Figure 6.36 A map showing the location of Nyungwe National
a young chimpanzee in Park in Rwanda
Nyungwe National Park,
Rwanda

To learn more about this

Questions for understanding chapter, check out this
lesson on the Singapore
What are the advantages and disadvantages of various Student Learning Space.
strategies to manage tropical forests sustainably go.gov.sg/lsg018
How effective are these strategies

SecGeoEX_NA_Course1_Ch6_3pfB.indd 154 06/07/20 5:28 PM

 CHAPTER GLOSSARY
Biodiversity The range of plant and animal species found within an ecosystem

An area comprising land, coastal and or marine ecosystems,

Biosphere reserve which is used sustainably and in harmony with the conservation 155
of biodiversity

Carbon storage The accumulation of carbon in solid forms

Conservation The protection of something of environmental importance from

(Conserve) damage or destruction

Controlled logging The cutting down of trees for wood in a restricted manner

Deforestation The permanent removal of natural vegetation from an area

Enhanced The increase in the average temperature of the earth’s surface

due to the presence of more greenhouse gases in the atmosphere
greenhouse effect trapping heat

The wearing away of the land surface by natural agents such as

Erosion (Erode) water and wind

Extraction (Extract) The act of obtaining or removing something from a place

Gases that contribute to the greenhouse effect by absorbing heat

Greenhouse gases and preventing it from escaping into outer space

Habitats Places that support different communities of organisms

Habitation The act of living in a particular place

A large natural area set aside to protect the ecosystems as well as

National park the plant and animal species that are characteristic of that area

Oxygen generation The production of oxygen through the process of photosynthesis

Photosynthesis The process through which green plants produce their own food
(Photosynthesise)
The process of raising people’s awareness and understanding
Public education of something

Materials that are still in their natural state, before being

Raw materials processed or manufactured into finished products

Reforestation
The process of replanting a deforested area with new trees
(Reforest)

SecGeoEX_NA_Course1_Ch6_3pfB.indd 155 06/07/20 5:28 PM

 INDEX
A F
156 adaptation 96, 110, 116, 120 flood 74, 77, 95
aerial root 99, 116, 117, 120, 121 flow 53, 56, 58, 62, 64, 65, 70, 71
agriculture 74, 80, 81, 87, 95 food chain 79
annual rainfall 98, 104, 120 forest structure 108, 120
atmosphere 4, 6, 7, 8, 9, 24 forestry 127, 146, 149
availability (of water) 35 freshwater 56, 58, 70, 71

B G
bedrock 61, 70 gaseous 55, 70
biodiversity 130, 141, 155 geography 4, 6, 11, 24, 25
biosphere 4, 6, 7, 10, 24 geographer 2, 4, 5, 13, 14, 15, 16, 17, 19, 20, 21,
biosphere reserve 148, 155 22, 24, 25
broad leaves 98, 110, 120 geographical investigation 5, 21, 22, 24
built environment 2, 4, 11, 12, 15, 16, 17, 19, 20, 21, 24, geographic scale 20, 24
25 glacier 52, 55, 56, 57, 70
buttress roots 98, 110, 111, 120 global scale 20
greenhouse gases 143, 144, 155

C groundwater
groundwater flow
52, 53, 56, 57, 60, 61, 62, 70, 71
53, 62, 70
canopy 98, 108, 120, 136
carbon storage 126, 128, 129, 155
catchment 53, 58, 63, 64, 66, 70, 71 H
climate 103, 120, 121, 130 habitat 126, 128, 130, 155
cluster 14 habitation 126, 134, 155
coast 104, 112, 113, 114, 120, 132, 134, 135 human geography 4, 11, 24
concept 5, 13, 14, 15, 16, 20, 21, 24 hydrosphere 4, 6, 9, 24
condensation 63, 70 hydrological cycle 9, 50, 53, 62, 63, 70
cone root 99, 117, 120
conservation (conserve)
consumption (consume)
106, 146, 147, 149, 154, 155
42, 48, 75, 80, 81, 86, 88, 89, 95
I
ice 55, 57, 70
contour lines 18
impact 39, 40, 42, 47, 69
controlled logging 149, 150, 155
import 75, 86, 92, 93, 94, 95
coordinates 13, 14, 25
industry 74, 80, 82, 87, 95
infiltration 53, 70
D infrastructure 12
deforestation 127, 141, 142, 144, 145, 151, 152, 155 input 52, 64, 65, 66, 70, 71
distribution 50, 53, 56, 70, 96, 97, 98, 102, 105, inquiry 5, 21, 24
115, 122 issue 21, 24
diversity 114, 120, 130, 141, 151, 155
domestic
drip-tips
74, 80, 95
98, 110, 111, 120
K
knee-bend roots 99, 117, 121
drought 74, 76, 77, 78, 89, 95

E L
lake 52, 56, 57, 58, 59, 70
ecosystem 72, 74, 79, 84, 95
latitude 13, 24, 120, 121
emergent layer 98, 108, 109, 120
layer 98, 108, 109, 111, 115, 120, 121
enhanced greenhouse effect 127, 141, 143, 144, 155
linear 14
environment 4, 5, 13, 16, 24
liquid 36, 52, 55, 70
equator 98, 102, 103, 105, 112, 120, 121
lithosphere 4, 6, 7, 8, 9, 24
erosion (erode) 126, 128, 132, 133, 155
local scale 20
evaporation 53, 55, 63, 66, 70
location 13, 14, 25
evergreen 98, 106, 114, 120, 128
longitude 13, 25
extraction (extract) 124, 127, 140, 141, 149, 152, 155
long term 40, 49, 86, 94, 95

SecGeoEX_NA_Course1_Index.indd 156 29/6/20 8:47 AM

 M S
management (manage) 26, 29, 42, 44, 48, 72, 75, 85, 86, 87, salinity 99, 112, 114, 115, 121
93, 94, 95 salt-excluding species 99, 116, 117, 121
mangrove 96, 97, 99, 104, 112, 113, 114, 115, salt-secreting leaves 99, 116, 121
116, 117, 121, 124, 127, 128, 129, 131, scale 5, 13, 17, 25
132, 133, 134, 135, 137, 138, 139, secondary data 22
142, 151, 153
map scale 17, 25
sediments 113, 121, 132, 133 157
sheltered environment 99, 113, 121
mean annual temperature 98, 104, 121
short term 40, 49, 86, 94, 95
mesosphere 8
soil 52, 56, 57, 60, 61, 70, 71
soil moisture 57, 60, 71
N solid 52, 55, 71
national park 106, 146, 148, 154, 155 space 5, 13, 14, 25
national scale 20 spatial pattern 14
natural process 34, 35, 36 store (storage) 50, 52, 56, 57, 58, 60, 62, 66, 71
natural vegetation 102, 103, 105, 112, 121, 155 stratosphere 8
net change 66, 71 supply 38, 49, 50, 54, 65, 79, 86, 92, 94, 95
surface runoff 53, 62, 66, 71, 77

O sustainable (sustainability) 28, 29, 40, 42, 49

ocean 52, 56, 57, 59, 71

output 53, 64, 65, 66, 71 T
oxygen generation 128, 155 technology 28, 32, 33, 42, 46, 49, 91, 92, 95
ozone layer 8 threat 39, 84, 95
thermosphere 8

P tide
time scale
114, 115, 117, 121, 132, 133
19, 20, 25
pattern 14, 22, 25
transpiration 53, 63, 66, 70, 71
pencil root 99, 117, 121
troposphere 8
percolation 53, 71
transport 4, 11, 45
phenomenon 20, 21, 22, 25
tributaries 77
photosynthesis 128, 129, 144, 155
Tropic of Cancer 13, 102, 104, 105, 112, 121
(photosynthesise)
Tropic of Capricorn 13, 102, 104, 105, 112, 121
physical environment 2, 4, 6, 7, 10, 11, 12, 15, 16, 17, 19, 20,
21, 24, 25 tropical climate 98, 104, 105, 106, 113
physical geography 4, 6, 25 tropical rainforest 96, 98, 99, 100, 105, 106, 107, 108,
109, 110, 114, 115, 120, 121, 124, 127,
physical state 50, 52, 55, 71
128, 129, 130, 132, 135, 137, 139,
place 5, 8, 13, 15, 25 140, 141, 142, 148, 152
pollution (pollute) 50, 52, 55, 71, 72, 75, 84, 85, 86, 87,
92, 95
pore 60, 71 U
precipitation 52, 62, 66, 70, 71 undergrowth layer 98, 108, 115, 121
primary data 22
prop root
public education
99, 117, 121
127, 146, 152, 156
W
water deficit 53, 64, 65, 66, 67, 71
water surplus 53, 64, 66, 67, 71
Q water vapour 55, 63, 70
quality 75, 80, 83, 84, 85, 86, 87, 94, 95 waxy leaf 98, 110, 111, 122

R Z
rainfall 76, 77, 95 zonation 99, 114, 115, 122
raw material(s) 126, 134, 139, 140, 156
recreation (recreational 74, 80, 95, 126, 134, 136
activities)
reforestation (reforest) 151, 156
relationship 4, 15, 17, 22, 24, 25
regional scale 20
river 50, 52, 55, 56, 57, 58, 59, 62, 63, 70,
71
river mouth 58, 59, 63, 71, 99, 113
river source 58, 62, 71

SecGeoEX_NA_Course1_Index.indd 157 29/6/20 8:47 AM

 ACKNOWLEDGEMENTS
We are grateful to the following for permission to reproduce copyright materials:

162 Cover: Abstract mountain landscape © Login/Shutterstock.com.

Chapter 1: p.2–3 Pang Sua Pond © Ministry of Education, Singapore; p.6–7 Fig 1.1 ID 112514990 © Jarosław Janczuk/Dreamstime.com; p.6 Fig 1.1 ID
91136879 © Lequint/Dreamstime.com; p.7 Fig 1.1 ID 61204489 © Ravindran Smith/Dreamstime.com, Fig 1.1 ID 150583856 © Lowlihjeng/Dreamstime.
com; p.8 Fig 1.2 Planet Earth © NASA; p.9 Fig 1.3 ID 12920241 © Adinabulina/Dreamstime.com, Fig 1.3 ID 164570400 © Irinachayko/Dreamstime.
com, Fig 1.4 Hunts Mesa © Valentyna Zhukova/123rf.com; p.10 Fig 1.5 ID 74336215 © Pavel Vorech/Dreamstime.com, Fig 1.6 Marine life © Andrey
Armyagov/123rf.com; p.11 Fig 1.7 Campsite © Vasin Leenanuruksa/123rf.com, Fig 1.8 HDB flats © andrewblue/123rf.com; p.12 Fig 1.9 ID 141205380 ©
Dven77/Dreamstime.com, Fig 1.10 ID 22293640 © Tanteckken/Dreamstime.com, Fig 1.11 Pasir Panjang port © Asia File/Alamy Stock Photo, Fig 1.12 ID
114324084 © Jimmytst/Dreamstime.com; p.15 Fig 1.17 Marina Floating Platform NDP © Jordan Tan/123rf.com; p.16–17 Fig 1.19 ID 73461774 © Jimmytst/
Dreamstime.com; p.17 Fig 1.20 Chek Jawa boardwalk © Hanjo Hellmann/Shutterstock.com.

Chapter 2: p.26–27 Deforestation in Amazon © luoman/iStock.com; p.32 Fig 2.3 Penan tribal house © Andrew Garton/https://commons.wikimedia.
org/wiki/File:Long_Kerong_(5101752612).jpg/CC BY-SA 2.0, Penan kitchen © Andrew Garton/https://commons.wikimedia.org/wiki/File:Fireplace_in_a_
typical_house_in_Long_Kerong.jpg/CC BY 2.5; p.33 Fig 2.4 ID 29164832 © Aleksandar Todorovic/Dreamstime.com, Fig 2.5 ID 111031126 © Airubon/
Dreamstime.com, Fig 2.6 ID 6250832 © Horst Kanzek/Dreamstime.com, Fig 2.7 ID 64601134 © Tawatchai Prakobkit/Dreamstime.com; p.38 Fig 2.10
MacRitchie Treetop Walk © Marshall Cavendish Education, Fig 2.10 Parks and Trees Act; p.42–43 Fig 2.13 Data for carbon footprint diagram © Christopher
M Jones, PhD, Director, CoolClimate Network, Program Chair, Behaviour Energy and Climate Change Conference, University of California, Berkeley,
Berkeley, CA 94720-3050, USA; p.43 Fig 2.14 ID 55641433 © Phanuwatn/Dreamstime.com, Fig 2.15 ID 75101144 © Alfred Hofer/Dreamstime.com,
Fig 2.16 ID 133447963 © Nonthawan Pisessith/Dreamstime.com; p.46 Fig 2.19 ID 83354781 © Jimmytst/Dreamstime.com, Fig 2.20 Building with
intergrated solar panels © Peellden/https://commons.wikimedia.org/wiki/File:WorkdGame2009_Stadium_completed.jpg/CC BY-SA 3.0; p.47 Fig 2.21
©ID 27017278 © Cyberjade/Dreamstime.com.

Chapter 3: p.50–51 ID 95355572 © Tea/Dreamstime.com; p.55 Fig 3.1 ID 12920241 © Adinabulina/Dreamstime.com, Fig 3.2 Hailstones © Suzanne
Tucker/Shutterstock.com; p.56–57 Fig 3.5 ID 34200769 © Woo Bing Siew/Dreamstime.com; p.61 Weep holes © Marshall Cavendish Education.

Chapter 4: p.72–73 Marina Barrage © komushiru/Shutterstock.com; p.76 Fig 4.1 Typhoon Tembin © FERDINANDH CABRERA/AFP via Getty Images,
Fig 4.2 California drought © Photo by Justin Sullivan/Getty Images; p.78 Fig 4.5 Flood © AJP/Shutterstock.com, Fig 4.6 ID 93669954 © Dreamstime
Agency/Dreamstime.com; p.80 Fig 4.9 © ID 4142542 © Lawrence Wee/Dreamstime.com, Fig 4.10 Fishing at Lower Peirce Reservoir © Win Suseno/
Shutterstock.com; p.83 Fig 4.13 Semicondutor plant photo by Christoph Schmidt/picture alliance via Getty Images, Fig 4.14 SWAN robot ©
Photographer: Manu Ignatius, Subnero PTE LTD, Singapore; p.84–85 Turtle eating plastic © Romolo Tavani/123rf.com; p.84 Fig 4.15 Ypacarai Lake
pollution © NORBERTO DUARTE/AFP via Getty Images; p.85 Fig 4.16 Dead eel in the Rhine © Keystone; p.87 Fig 4.18 Upper Seletar Reservoir © Derek
Teo/Shutterstock.com, Fig 4.19 ID 70481509 © Waihs/Dreamstime.com; p.88 Fig 4.20 Social media post © PUB; p.89 Fig 4.21 Water wise poster ©
Nelson Mandela Bay Tourism; p.90 Fig 4.22 Water-saving tips © PUB; p.90–91 Fig 4.23 Desalination process © PUB; p.91 Boy © tinna2727/123rf.com; p.92
Fig 4.24 AI-powered machine © Courtesy of IntelliFlux Controls Inc; p.94 Fig 4.26 © Tijana Drndarski/Shutterstock.com.

Chapter 5: p.96–97 ID49497890 © Michal Knitl/Dreamstime.com; p.102 Temperate grassland © zqmai/123rf.com, Temperate deciduous forest © Geraldas
Galinauskas/123rf.com, ID 22171417 © Albertoloyo/Dreamstime.com, Tropical forest © Pablo Hidalgo/123rf.com; p.103 Tundra © Marina Vdovkina/123rf.
com, ID 163756840 © Svetlana Buzmakova/Dreamstime.com, Desert © Matyas Rehak/123rf.com, Tropical grassland © czekma13/123rf.com; p.106
Fig 5.4 Tropical rainforest in Khao Yai National Park © Khongchum/123rf.com; p.107 Fig 5.5 Tembusu tree © Flora&FaunaWeb, National Parks Board (Tee
Swee Ping), Tembusu fruit © Flora&FaunaWeb, National Parks Board (Tee Swee Ping), Tembusu flower © Flora&FaunaWeb, National Parks Board (Ang
Wee Foong), Tempinis tree © Flora&FaunaWeb, National Parks Board (Boo Chih Min), Tempinis fruit © Flora&FaunaWeb, National Parks Board (Ang
Wee Foong), Tempinis flower © Flora&FaunaWeb, National Parks Board (Ang Wee Foong); p.111 Fig 5.7 Waxy leaves © Chumrit Tejasen/Shutterstock.
com, Fig 5.8 Buttress roots © Damian Pankowiec/Shutterstock.com; p.112 Fig 5.9 Mangrove forest in Thailand © somchai rakin/123rf.com; p.116 Fig 5.12
Salt crystals on leaf © Denis Marec/Shutterstock.com; p.117 Fig 5.13 Avicennia roots © Chad Zuber/123rf.com, Sonneratia roots © Charlie_Palmares/
Shutterstock.com, Rhizophora roots © NUNNICHA SUPAGRIT/123rf.com, Bruguiera roots © Dale Lorna Jacobsen/Shutterstock.com.

Chapter 6: p.124–125 Mangrove reforestation project © Pratan Saetang/Shutterstock.com; p.130 Fig 6.3 Tapir © Panthat Sitdatviradee/123rf.com,
Caiman © anagram1/123rf.com, Frog © dirkercken/123rf.com, Toucanet © Ondrej Prosicky/123rf.com, Piranha © Andrea Izzotti/123rf.com; p.131 Fig 6.4
Crabs © Heri Mardinal/123rf.com, Egret © Dave Montreuil/123rf.com, Pelican © ammit/123rf.com, Mudskipper © chaninaryamuang/123rf.com, Heron
© Brian Lasenby/123rf.com, ID 130591470 © Phillip Lowe/Dreamstime.com, Otter © frankfichtmueller/123rf.com; p.134 Fig 6.7 Tribe dwellings © Sergey
Uryadnikov/Shutterstock.com, Fig 6.8 Korowai tribespeople © Sergey Uryadnikov/Shutterstock.com, Fig 6.10 Moken person fishing © Justine Evans/
Alamy Stock Photo, Fishing boats © fototrips/Shutterstock.com; p.136 Fig 6.12 ID 125812124 © Nuvisage/Dreamstime.com; p.137 Fig 6.13 Cashew nuts
© karandaev/123rf.com, Mangoes © Iamsumang/123rf.com, Eggplants © Maksym Narodenko/123rf.com, ID 71309750 © Jun Yu Foo/Dreamstime.com,
Cocoa pod © sirichai asawalapsakul/123rf.com, Cinnamon sticks © Mohammed Anwarul Kabir Choudhury/123rf.com, Bananas © Sarot Chamnankit/123rf.
com; p.138 Fig 6.14 Forest background © lakhesis/123rf.com, Mentawi tribesman hunting © Andrey Gudkov/123rf.com, Mentawi tribesman cooking
©Andrey Gudkov/123rf.com, Fig 6.15 ID 148095672 © Siam Pukkato/Dreamstime.com; p.139 Fig 6.16 Teak © kiatdumrong/123rf.com, Rosewood ©
Khuntnop Asawachiwantorngul/123rf.com, Ebony © Kim Takhyzh-Sviridov/123rf.com, Mahogany © mironovak/123rf.com; p.140 Fig 6.17 Cleared rainforest
area © Andrey Radchenko/123rf.com; p.146 Fig 6.24 ID 127284283 © Mortenhuebbe/Dreamstime.com, Fig 6.25 ID 52706255 © Jimmytst/Dreamstime.
com; p.147 Fig 6.26 ID 55005192 © Jimmytst/Dreamstime.com, ID 54681909 © Jimmytst/Dreamstime.com, ID 124093590 © Deming9120/Dreamstime.
com, Labrador © EQRoy/Shutterstock.com; p.148 Fig 6.27 Gunung Leuser © dennisvdw/istockphoto.com; p.151 Fig 6.31 Mangrove reforestation ©
National Parks Board; p.152 Fig 6.32 Nursery with seedlings © Alf Ribeiro/Shutterstock.com; p.152–153 Fig 6.33 ID 142428277 © Jimmytst/Dreamstime.
com; p.154 Fig 6.34 Tourist visting park © Tetyana Dotsenko/Shutterstock.com, Fig 6.35 ID 146902604 © Atosan/Dreamstime.com

SecGeoEX_NA_Course1_Acknowledgement.indd 162 9/7/20 9:39 AM

 GEOGRAPHY
Aligned with th e new syllab u s , th is c o u rs e b o o k is writte n u s in g th e a p p r o a c h o f
G eogr ap h ical Inquiry, in vitin g y o u to e x p lo re a n d in v e s tig a te im p o rta n t p h e n o m e n a
and issu e s in o u r enviro n ment. I t is d e s ig n e d to ig n ite y o u r c u rio s ity, a n d d e v e l o p

Exp r e ss / N o r m al ( Acad e m i c)
L o w e r Se co n d ar y G e o g r ap h y Co u r s e b o o k ( B o o k O n e )
geogr aph ical thin kin g to ask cru c ia l g e o g ra p h ic a l q u e s tio n s re g a rd in g is s u e s a b o u t y o u r
envi r onment in a mean ingfu l a n d c ritic a l m a n n e r. Yo u will u n d e rs ta n d th e g e o g r a p h i c a l
concept s o f space, place , sca le a n d e n v iro n m e n t. Yo u will le a rn a b o u t t h e p h y s i c a l
pr ocesses th at co n tribute to th e fo rm a tio n s th a t m a k e u p th e la n d s c a p e s o n E a r t h . Yo u
w i l l j our ney thro u g h the in ter a c tio n s b e twe e n th e p h y s ic a l a n d b u ilt e n v i r o n m e n t i n
r elat ion to h u man activitie s. Mo s t im p o rta n tly, y o u will d e v e lo p th e a wa re n e s s o f t h e
need f or sustainab ility in u tilis in g re s o u rc e s fo r d e v e lo p m e n t.

SecGeoEX_NA_Course1_Cover.indd 1 14/7/20 8:57 AM