Green Science and Environment 7 Final (2076)

Fig.f. Economic Development

Various natural resources are used for operating various developmental
activities. For example, soil, stone, etc. are used to construct roads, buildings,
etc. Similarly, various natural resources are used as raw materials to produce
various goods in the factories or industries. Water resources are used to produce
hydroelectricity. All these activities conducted for physical development are
the sources of economic development also. Thus, natural resources have a
great importance for economic development of a country.

Conservation of Natural Resources

Human beings use various natural resources for their livelihood. In the
absence of natural resources, the lives of human beings and other living
beings are not possible. The rational use of natural resources is essential.
Misuse or abuse of natural resources invites environmental degradation
resulting in environmental imbalance. Thus, it is necessary to conserve various
types of natural resources available in nature to maintain balance in natural
environment. In this connection, brief description of some natural resources
with their importance and ways of conservation is presented.

Water Resources

There are various water resources
on the earth. They are surface water,
underground water, rain water, etc.
The sources of water found on the
earth are called water resources.
Water is a very essential natural
resource for all living beings for
their survival. Similarly, water is
useful for various purposes like 21.5
irrigating, washing, cleaning, etc.
besides drinking. Living beings ranging from microorganisms to large animals
along with all types of plants cannot survive without water. Thus, water is a
very important natural resource for all living beings.

Various types of water bodies like lake, pond, river, etc. are available on the
earth surface. The water found in such bodies is called surface water. It is
collected on the earth by rain. Surface water evaporates due to the heat of the
sun. The sources of water found under the earth surface are called sources
of underground water. Underground water is pulled on the earth surface for
various purposes. The water obtained from precipitation (rain) is called rain

GREEN Science and Environment Book-7 251

water. Rain water is very essential for both animals and plants. Our country is
rich in water resources. Various types of water resources like rivers, streams,
ponds, lakes, wetlands, watersheds, fountains, etc. are abundant in Nepal.

Importance of Water Resources

Various types of water resources are the main sources of water on the earth.
These water sources are essential for all living beings for their survival.
Similarly, water is equally important for various activities like washing,
cleaning, irrigating, industrial work, transportation, recreation, etc. The
importance of water is given in the following points.

1. Water is an essential component for all living beings for their survival.
Animals drink water and green plants need water to prepare their food
during photosynthesis. Thus, water resources are important for the survival
of all living beings.

2. Water resource are important for household works like cleaning, washing,
cooking, bathing, etc.

3. Water resources are essential for irrigating agricultural farms.

4. Water resources are important for tourism industry. Boating, rafting,
swimming, rowing, etc. are water related sports of tourism industry.

5. The major source of renewable energy, hydroelectricity is generated from
water resources.

6. Various means of transportation like boat, ship, motor boat, etc. are operated
on water.

7. Water resources are essential to conserve wildlife and vegetation.

8. Hydroelectricity generated from water resources is used to operate various
means of transportation like cable car, trolly bus, train, electric car, etc.

9. Water is used in industries, factories, construction areas, etc. for various
purposes. For example, water is used to construct buildings, bridges, etc.
Similarly, water is essential for producing thermoelectric power, refining oil,
extracting natural gas, etc. in the factories and industries.

10. Water resources are very much helpful for maintaining environment
balance by helping the survival of both animals and plants in their natural
environment.

11. Water resources are the habitats of various aquatic animals and plants.

252 GREEN Science and Environment Book-7

Fig.Conservation of Water Resources

Water resource is one of the important natural resources that provide water
to all living beings and non-living things. It is necessary to conserve various
water resources for the existence of both plants and animals in the earth. Water
resources should be conserved to meet the need of increasing population at
present. Similarly, it is necessary to protect habitats of both aquatic animals
and plants to maintain environment balance. The overuse and unmanaged use
of water should be avoided. Likewise, water resources should not be polluted.
Conservation of forests is essential to conserve water resources.

Activity 2

Make a visit to a nearby water resource area in your locality to study about the
water resource. Make a short note on importance and ways of conservation
of that water resource on the basis of your study.

Watershed

A watershed refers to the entire
region draining into a river, river
system or other water bodies. It is an
area of land that contains a common
set of streams and rivers that all
drain into a larger body of water.
In such area surface water from
rain or melting snow converges
to a single point. Thus, the area
around various water resources is a 21.6
watershed. In Kathmandu valley, the water collected in Shivapuri-Nagarjun
area is an example of watershed. This watershed is source of water of Bagmati
and Bishnumati rivers in Kathmandu. Similarly, the area around Phewatal in
Pokhara is Phewatal watersed. In Kulekhani, human made lake is formed for
collecting water from Kulekhani watershed. Likewise, Gandaki, Koshi and
Karnali are big watershed of our country. There are many small watersheds
in Nepal.

Importance of Watershed

Watersheds are sources of water required for various purposes. The importance
of watershed is pointed out below.

1. Watersheds fulfill the requirement of water for animals and plants of the
watershed located areas.

GREEN Science and Environment Book-7 253

2. Watersheds conserve forests and vegetation of the watershed area.

3. Watersheds protect agricultural lands and help increase agricultural
productivity.

4. Watersheds maintain the system of environmental balance and also conserve
environmental balance.

5. Watersheds provide habitats to various animals and plants.

Conservation of Watersheds

Watersheds are good sources of water required for various purposes. It is
necessary to conserve watershed to conserve source of water essential for both
animals and plants. But, watersheds are in crisis due to the massive exploitation
of land and forest resources to fulfill the needs of increasing population.
Conserving watersheds is essential to conserve natural environment.
Afforestation, planting grass, management in farming, etc. can be done to
conserve watersheds. Similarly, awareness programmes related to importance
and conservation of water should be conducted for awareness to conserve
watersheds.

Wetland

A land area which is saturated with

water permanently or seasonally,

is called wet land. It is the link

between land and water. Swamp,

marsh, blog, etc. are some of the

common names of different types of

wetlands. According to the nature Fig.

and type of wetland, it may be filled

mostly with moss, grasses, herbs, 21.7
shrubs, trees, etc. Marshes and

ponds, the edge of a lake or ocean, low-lying areas that frequently flood are

examples of wetlands. Generally, wetlands are common in the Terai region.

The water bodies having a water level less than 6 m are defined as wetlands.

According to the study of IUCN, there are 163 wetlands in the Terai region of
Nepal. Similarly, 164 wetlands are in the Hilly region and 78 wetlands are in
the Mountain region. The Koshi Tappu Wildlife Reserve is the first wetland
enlisted as the Ramsar site in 1987 AD. There are many ponds, lakes, swamps,
glaciers, marshes, etc. in our country. Both natural and artificial wetlands are
found in Nepal. Thus, Nepal is rich in wetlands.

254 GREEN Science and Environment Book-7

Importance of wetlands

Wetlands are the sources of water essential for both animals and plants. The
importance of wetlands is pointed out below.
1. Wetlands are suitable habitats for birds.

2. Wetlands provide water for agricultural activities.

3. Wetlands help in maintaining environmental balance.

4. Wetlands provide habitats to different kinds of creatures.

5. Wetlands are good water resources for human beings.

6. Wetlands are used for fish farming.

7. Wetlands help in water-tourism.

8. Wetlands are important for conservation of biodiversity.

9. Wetlands help in controlling soil erosion and flood.

Conservation of Wetlands

Various activities of human beings adversely affect wetlands. Such activities
are expanding residential areas, extending farming lands by drying water of
wetlands, excessive use of water from the wetlands, polluting wetlands by
throwing garbages and agricultural byproducts, etc. Thus, it is essential to
conserve wetlands in order to conserve natural source of water.

Various efforts have been made at the national and international level to
conserve wetlands. An international conference was held in the city of Ramsar
of Iran in 1971 AD. It rectified an accord regarding conserving wetlands.
Many wetlands of Nepal have been enlisted as the wetlands of international
importance. Such wetlands are the Koshi Tappu Wildlife Reserve, Bis Hajari
Lake of Chitwan, Ghodaghodi Lake of Kailali, etc. It is necessary to conserve
wetlands to maintain natural ecosystem, to conserve biodiversity and for
community development. It is necessary to stop misuse and overuse of water
of wetlands. Wetlands can be conserved by stopping expansion of farming
land and residential areas by drying wetlands. Similarly, we should not pollute
wetlands by throwing garbages, industrial byproducts, etc. in wetlands.
Likewise, various programmes regarding the importance of wetlands should
be conducted to generate awareness among people in order to conserve
wetlands.

GREEN Science and Environment Book-7 255

Fig.Activity 3
Make a visit to a nearby wetland in your locality and prepare a short
description by addressing the following questions.
1. What is the importance of the wetland of your study area?
2. What are the problems of the area that may harm wetlands?
3. What may be the ways of conserving the wetland of the study area?

Fundamental Components of Environment

We can see various types of living beings and non-living things around
us. The totality of these, all kinds of living beings and non-living things, is
environment. Living beings include all types of animals and plants. Soil, water,
air, land, sunlight, humidity, etc. are non-living things. Thus, environment is
the physical and biological world where living beings exist and non-living
things remain with continuous interaction. The components of environment
are broadly categorised into biotic components and abiotic components. All
animals and plants are biotic components of environment. Similarly, water,
air, soil, rainfall, sunlight, etc. are abiotic components of environment. In this
connection, the fundamental components of environment are described below
briefly.

21.8

Abiotic Components of Environment

The non-living components like soil, air, water, rainfall, sunlight, etc. are the
abiotic components of environment. The fundamental abiotic components of
environment are water, air and soil. A brief description of these components is
presented below.

Water

Water is one of the fundamental abiotic components of environment. It is
essential for the survival of all living beings. It is a compound formed by
combination of hydrogen and oxygen. A water molecule contains two atoms

256 GREEN Science and Environment Book-7

Fig.of hydrogen and one atom of oxygen. Water can be found on the earth surface
and under the earth surface. Various types of water bodies like river, streams,
ponds, lakes, wetlands, watersheds, etc. are the sources of water. Two thirds
parts of the earth is occupied by water bodies.
Sources of water are broadly classified into surface water, under ground water
and rain water. There should be proper balance among these three sources of
water. Surface water evaporates due to the heat of the Sun. It takes the form of
cloud in the sky and falls in the earth in the form of rain. This rain is the form
of rain fall. It is the source of surface water and underground water.
We use surface water and underground water for various purposes like
drinking, washing, cleaning, irrigating, transportation, industrial activities,
etc. Underground water can be taken on the earth surface by digging well,
through water pump, etc. Rain water is suitable for agricultural activities.
Excessive use of water resources adversely affects environmental balance.
Polluted water due to mixing of various types of industrial byproducts and
other substances is harmful for both animals and plants. Thus, water resources
should be conserved in order to maintain environmental balance.

21.9

Air

Air is one of the fundamental abiotic components of environment. It is a
mixture of various gases. It consists of 78% nitrogen, 21% oxygen and 1% other
gases. The other gases include carbon dioxide, helium, neon, etc. The earth is
surrounded by a layer of air. This layer is called atmosphere. Besides, humidity
and dust particles are also found in air.
Air is a basic life component for both animals and plants. Both plants and
animals take oxygen in and throw carbon dioxide out during respiration. Green
plants need carbon dioxide during photosynthesis. Oxygen is the byproduct
of photosynthesis. In this way, there is a regular flow of carbon dioxide and
oxygen in the environment. It is necessary to maintain the balance of carbon
dioxide and oxygen in the environment for the survival of both animals and

GREEN Science and Environment Book-7 257

Fig.plants. There might be shortage of oxygen in the environment on decreasing
green plants. Absence of oxygen results in difficulty in survival of animals.
The imbalance in the amount of gases in environment results in air pollution.
Air pollution is harmful for both animals and plants.

The increment in carbon dioxide, sulphur dioxide, nitric oxide, etc. causes
air pollution. Similarly, the gas emitted from foul and decayed materials also
pollutes air. Thus, it is necessary to reduce consumption of petroleum products
in industries and vehicles to conserve air. Similarly, afforestation should be
done to maintain proper balance among various gases. We can conserve
natural environment by conserving air of atmosphere.

Land

Among various fundamental
abiotic components of environment,
land is one of them. Land is the
combination of soil and rocks. Land
is very essential for both animals
and plants. Almost all living beings
get food and habitat from the land.
Terrestrial plants grow on land,
animals get their food from land
and all land animals including 21.10
human beings live on land. Thus, land is very important for all living beings.
It is essential to conserve land to maintain environmental balance. Various
activities of human beings adversely affect natural condition of land. Excessive
use of insecticides and pesticides pollute soil. Polluted soil is harmful for both
animals and plants. Polluted soil is not suitable for agricultural activities.
Similarly, polluted soil pollutes water bodies. Ultimately, it creates problems
in natural environment necessarily for maintaining the ecosystem. Therefore,
it is necessary to conserve land in order to conserve natural environment and
maintain environmental balance.

Biotic Components of Environment

Various living beings (microorganisms, animals and plants) are biotic
components of environment. The living beings of an environment are called
biotic components of environment. The biotic components of an environment
are broadly classified into producers, consumers and decomposers. These are
the fundamental biotic elements of environment. The brief description of these
components is presented below.

258 GREEN Science and Environment Book-7

Producers Fig. Fig.

Green plants of the environment
can prepare their own food by using
solar energy, carbon dioxide and
water. These are called producers
since they can produce their
food. The process by which green
plants prepare their food is called
photosynthesis. Thus, green plants
are producers. Producers are also
called autotrophs since they have 21.11
the ability to prepare their food.

Consumers

A large section of living beings in environment depends upon plants directly or
indirectly for their food. These living beings are consumers. The living beings
which depend on producers for their food are called consumers. Consumers
have not the ability to prepare their food on their own. Human beings, animals
like goat, cow, sheep, dog, tiger, etc. are all consumers. Consumers are broadly
categorized into primary consumers, secondary consumers and teritiary
consumers.

1. Primary Consumers

The consumers that feed on green
plants only are called primary
consumers. In other words, primary

consumers directly depend on

green plants for their food. For

example, cow, goat, deer, sheep, etc.

Primary consumers are also called

herbivores since they feed on plants 21.12
only.

2. Secondary Consumers

The consumers that feed on primary consumers are called secondary
consumers. Secondary consumers directly depends on animals, but indirectly
depend on plants. For example, dog, cat, fox, etc.

GREEN Science and Environment Book-7 259

Fig. Fig.3. Tertiary Consumers
The consumers that feed on
primary consumers and secondary
consumers are called tertiary
consumers. For example, tiger, lion,
leopard, kingfisher, hawk, etc. The
animals which feed on flesh only
are called carnivores. Likewise, the
animals that feed on both animals
and plants are called omnivores.
Tiger, lion, etc. are carnivores and 21.13
man, dog, bear, etc, are omnivores.

Decomposers

The biotic components of
environment that break down
the remains of dead animals and
plants are called decomposers.
For example, bacteria, fungi,
etc. They decompose dead and
deacying bodies into simple
substances by acting upon them.
Decomposers produce nutrients 21.14
from biodegradable materials that
are essential for the growth of green plants in environment.

Activity 4

Make a list of any 12 biotic components found around you and classify them
under producers, consumers and decomposers. Also, classify consumers
under primary consumers, secondary consumers and tertiary consumers.

Role of Human Beings in Environmental Balance

Human beings are rational animals of environment. They have great role in
conserving environment and maintaining environment balance. The activities
of human beings that adversely affect natural environment are the major
causes of environmental imbalance. Thus, human beings have a great role
in maintaining environmental balance. Human beings use various natural
resources like water, land, plants, minerals, etc. for various purposes. Hazard
and excessive use of such natural resources is the major cause of degradation

260 GREEN Science and Environment Book-7

in environment. The planned and rational use of natural resources help in
maintaining natural environment. Similarly, various activities of human
beings pollute natural environment. Excessive use of petroleum products in
industries, factories, vehicles, etc. pollutes air around us. Polluted air is harmful
for both plants and animals. Therefore, human beings should play a great
role to conserve the atmosphere by reducing excessive use of petrol, diesel,
coal, etc. that are responsible for polluting natural environment resulting
in environmental imbalance. Similarly, the modification in landforms for
agricultural activities may be the cause of soil erosion, flood, landslides, etc.
Thus, human beings should play a great role to conserve natural landforms
by rational use of soil and land. The natural environment including all biotic
and abiotic components can be preserved by plantation, stopping pollution in
different levels and using natural resources in well planned manner rationally.

Impact of Human Activities on Environment

Human beings use various natural resources from environment to meet their
needs. Thus, they modify natural environment. The modification in physical
and biological environment is the great cause of environmental degradation.
The major impacts of human activities on environment are pointed out below.

i. Various human activities pollute air, water, soil, etc. of natural environment.
It is the major cause of environment degradation.

ii. Excessive use of natural resources creates environmental imbalance and
degradation in natural environment.

iii. Deforestation for expanding residential area and cultivating land is the cause
of environmental imbalance and degradation by inviting natural disasters.

iv. The use of insecticides and pesticides for agricultural activities pollutes various
components of environment. It creates imbalance in natural environment and
degrades natural environment.

v. Destruction of water resources like watersheds, wetlands, ponds, etc. causes
environmental imbalance since it destructs natural habitats of various plants
and animals.

Effects of Environment Degradation on Human Beings

Environmental degradation has adverse effect on the overall natural
environmental condition including the abiotic and biotic components. The
adverse effects of environmental degradation on human beings are pointed
out below.

i. Degradation in suitable climatic condition for human beings.

GREEN Science and Environment Book-7 261

ii. Possibility of various natural disasters like flood, soil erosion, landslide, etc.
iii. Outbreaking of various fatal diseases like cholera, malaria, etc.
iv. Scarcity of fresh air and water required for survival of human beings.
v. Problems in human health due to air pollution, water pollution, noise

pollution and soil pollution.
vi. Degradation in agricultural productivity.
vii. Destruction of water resources and decline in wildlife.
viii. Degradation in natural ecosystem and natural environment essential for

human beings.

Role of Human Beings in Conserving Environment

Among all components of environment, human beings are wise and rational
animals. They can conserve environment by various ways. Some of the ways
that can be adopted to conserve environment are given below:
i. Wise and rational use of natural resources.
ii. Reduction in harmful gases released from vehicles, factories, industries, etc.
iii. Proper disposal of waste materials to stop air pollution, water pollution, soil

pollution, etc.
iv. Rational and wise use of chemical fertilizers, insecticides, pesticides, etc. for

agricultural activities.
v. Conservation of various water resources like lakes, rivers, ponds, watershed,

wetlands, etc.
vi. Construction of various infrastructures like roads, bridges, buildings, etc.

rationally and scientifically.
vii. Stopping poaching of wild animals for various purposes.
viii. Discouraging deforestation and encouraging afforestation.
ix. Conducting awareness programmes regarding the conservation of natural

environment to maintain environment balance.

Activity 5
Conduct an awareness programme regarding the conservation of environment
around your school.

262 GREEN Science and Environment Book-7

Key Concepts

1. Natural resources refer to the resources that are available in natural
environment.

2. Natural resources provide suitable environment for all living beings for
their life in the environment.

3. The natural resources like solar energy, wind energy, tidal energy, etc. have
never-ending supply. These are perpetual natural resources.

4. The natural resources that can be used repeatedly by creating them again
and again and do not deplete from the environment are called renewable
resources.

5. Non-renewable natural resources refer to the resources that cannot be used
again and again and get exhausted after their use.

6. Various natural resources found in nature are the sources of food for living
beings.

7. Misuse or abuse of natural resources invites environmental degradation
resulting in environmental imbalance.

8. The sources of water found on the earth are called water resources.

9. Various types of water resources like rivers, streams, ponds, lakes, wetlands,
watersheds, fountains, etc. are abundant in Nepal.

10. Water is equally important for various activities like washing, cleaning,
irrigating, industrial work, transportation, recreation, etc.

11. Water resource is one of the important natural resources that provide water
to all living beings and non-living things. It is necessary to conserve various
water resources for the existence of both plants and animals on the earth.

12. A watershed refers to the entire region draining into a river, river system or
other water bodies.

13. Watersheds fulfill the requirement of water for animals and plants of the
watersheds located areas.

14. Watersheds are good sources of water required for various purposes. It is
necessary to conserve watershed to conserve source of water essential for
both animals and plants.

15. A land area which is saturated with water permanently or seasonally is
called wet land.

16. The water bodies having a water level of less than 6 m are defined as
wetlands.

GREEN Science and Environment Book-7 263

17. Environment is the physical and biological world where living beings exist
and non-living things remain with continuous interaction.

18. The non-living components like soil, air, water, rainfall, sunlight, etc. are the
abiotic components of environment.

19. Air is a basic life component for both animals and plants. Both plants and
animals take oxygen in and throw carbon dioxide out during respiration.

20. Afforestation should be done to maintain proper balance among various
gases. We can conserve natural environment by conserving air of atmosphere.

21. The living beings of an environment are called biotic components of
environment.

22. The process by which green plants prepare their food is called photosynthesis.
23. The living beings which depend on producers for their food are called

consumers.
24. The consumers that feed on green plants only are called primary consumers.
25. The consumers that feed on primary consumers and secondary consumers

are called tertiary consumers.
26. The biotic components of environment that break down the remains of dead

animals and plants are called decomposers.
27. The activities of human beings that adversely affect natural environment

are the major causes of environmental imbalance.
28. The modification in physical and biological environment is the great cause

of environmental degradation.
29. The use of insecticides and pesticides for agricultural activities pollutes

various components of environment. It creates imbalance in natural
environment and degrades natural environment.

Exercise

1. Tick (√) the correct statement and cross (×) the incorrect one.

a. Perpetual resources are limited in nature.

b. Forest is the habitat of wild animals

c. Watersheds and wetlands are resources of water.

264 GREEN Science and Environment Book-7

d. Soil, water, air, etc. are abiotic components.

e. Tertiary consumers directly depend on plants for their food.

2. Fill in the blanks using appropriate words.
a. Both living beings and ...................... are natural resources.
b. Non-renewable resources are ......................in nature.
c. ...................... resource is essential for aquatic-tourism.
d. A land area saturated with water is called ......................
e. Components of environment are broadly categorized into ......................
and abiotic components.

3. Answer the following questions:
a. What is environment? What does balance in environment mean?
b. Define natural resources with any three examples.
c. What are perpetual resources? Give any four examples.
d. What does habitat of animals and plants mean?
e. Define water resources with examples.
f. Why is it necessary to conserve water resources?
g. What are watersheds? Why are they important?
h. Name any three fundamental abiotic components of environment.
i. What is meant by biotic components of environment? Give any two
examples.
j. Define producers with examples.
k. What are decomposers? Why are they important?

4. Differentiate between:
a. Renewable resources and Non-renewable resources
b. Watersheds and Wetlands
c. Biotic components and Abiotic components
d. Primary consumers and Secondary consumers

GREEN Science and Environment Book-7 265

5. Write short notes on:
a. Water resources
b. Consumers
c. Importance of air
d. Environment degradation

6. Explain the importance of natural resources in a brief paragraph.
7. Mention any five importance of water resources.
8. How can we conserve water resources? Explain in detail.
9. Why are watersheds and wetlands important? How can we conserve

them?
10. Describe the importance of soil and air for living beings.
11. Prepare a flow chart to show fundamental components of environment.

Give any two examples for each category.
12. Describe the role of human beings to maintain environmental balance.
13. List any five impacts of human activities on environment.
14. What are the effects of environmental degradation on human beings?

Mention any five major ones.
15. How can human beings conserve natural environment? Enumerate any

five major ways.

266 GREEN Science and Environment Book-7

Environmental
UNIT Degradation and Its

22 Conservation

Weighting Distribution (Approximate) Teaching periods : 5 Marks (in %): 1

Before You Begin

Environment is the totality of physical and biological world around us. The
major aspects of environment are natural, biological, social and cultural. The
disturbance in any aspect of the environment is the cause of environmental
degradation. Environmental degradation refers to the deterioration in any aspect
of the environment due to human activities that have adverse effects on natural
environmental degradation. Destruction of natural resources, pollution of various
components of environment, destruction of natural habitats of animals and plants,
excessive use of natural resources, depletion in cultural heritages, etc. are the major
causes of environmental degradation. Environmental degradation invites various
natural disasters like flood, landslides, earthquake, volcano, etc. It is necessary to
maintain natural environment by conserving various components of environment.

Learning Objectives Syllabus

After completing the study of this unit, students will be • Introduction to environmental
able to: degradation and its causes

i. introduce environmental degradation and tell • Deforestation, its causes and effects
the causes of environmental degradation. • Urbanization and Industrialization
• Effects of destruction of natural
ii. mention the causes of deforestation.
resources on vegetation, animals, birds,
iii. tell the effects of deforestation. water resources, fuel, air, land and
minerals.
iv. describe urbanization and industrialization. • Introduction to natural disasters
(earthquake and volcano), their causes,
v. explain the effects of destruction of natural effects and preventive measures
resources on vegetation, animals and birds. • Environmental sanitation
• Efforts on environmental conservation
vi. describe water resources, fuel, air, land, (awareness, integrated conservation
minerals. effort, public participation, afforestation)
conservation of wildlife and vegetation,
vii. introduce natural disasters (earthquake, environmental sanitation, conservation
volcano). and promotion of cultural heritages)
• Government Agencies involved in
viii. define environmental sanitation and tell the Environmental Conservation (Ministry
ways of environmental sanitation. of Science and Technology and
Environment) and Ministry of Forests
ix. explain the efforts that can be made for and Soil Conservation)
environmental conservation.

x. describe various governmental agencies
involved in environmental conservation.

Glossary: A dictionary of scientific/technical terms

degradation : the damage or disturbance in any aspect of something
conservation : a careful preservation and protection of something, planned management
monument
canopy of natural resources to prevent exploitation, destruction, etc.
pathogenic : a building, column, statue, etc.
: a layer that spreads over an area like a roof
: related to things that cause diseases

GREEN Science and Environment Book-7 267

Fig.Environmental Degradation and Its Conservation

Causes of Environmental Degradation

There are various causes of environmental degradation. Basically, various
human activities like deforestation, urbanization, industrialization, etc. are
the major causes of environmental degradation. A brief description of these
human activities with their causes and their effects in natural environment is
presented below.

Deforestation

Forest is a very important natural
resource. It provides food and
habitat to animals including human
beings. Human beings obtain
various materials from forest that
are used for various purposes like
construction, making furniture,
etc. Forest is the home for wild
animals. Both wild animals and
domesticated animals get fed from 22.1
forest. Different human activities
are responsible for destruction of forest. The act of clearing forest for various
purposes like excessive use of forest timber for construction work, expansion
of agricultural land and residential area, etc. is called deforestation. The major
causes of deforestation are given below.

Causes of Deforestation

i. Expansion of cultivating land and residential area by clearing forest
hapazardly.

ii. Unplanned and unmanaged grazing and extension of pastureland.

iii. Forest fire and wild fire.

iv. Expansion of unmanaged industrialization.

v. Migration of people in unplanned manner

vi. Rapid growth in construction works leading to overuse of timber

vii. Using firewood as major source of fuel

viii. Natural disasters like soil erosion, landslides, flood, etc.

268 GREEN Science and Environment Book-7

Fig.Effects of Deforestation

The major effects of deforestation is environmental imbalance. Forest plays a
prominent role to create natural environment. It maintains balance between
carbon dioxide and oxygen. It results in environmental balance required
for both animals and plants. Also, forest maintains proper water cycle.
Deforestation has various adverse effects on natural environment which are
mentioned below.

i. Imbalance between carbon dioxide and oxygen by reducing the amount of
oxygen and increasing amount of carbon dioxide in environment.

ii. Climate change and global warning.

iii. Disturbance in natural water cycle.

iv. Destruction of habitats of wildlife

v. Loss in medicinal herbs and timber

vi. Extinction of various rare plants and animals

vii. Reduction in fertility of soil

viii. Possibility of various natural disasters like soil erosion, landsides, floods, etc.

ix. Adverse effect in agricultural system due to climate change, acid rain, draught,
scarcity of water, natural disasters, etc.

Thus, it is necessary to conserve forest resources by afforestation, conducting
awareness programmes, conserving forest plants, grass land and pasture
land, utilizing forest resources wisely, stopping forest fire and prohibiting
haphazard clearing of forests.

Urbanization

Urbanization is the process of
expanding residential areas or
establishing cities or towns by
construction of large buildings
in search of modern facilities. At
present, people migrate to city areas
in search of various facilities like
employment, education, health, etc.
It causes over population which is
the cause of over pressure and over 22.2
use of natural resources like water,
air, etc. Ultimately, excessive use of natural resources results in environmental

GREEN Science and Environment Book-7 269

degradation. Similarly, various types of pollutions like air pollution, water
pollution, land pollution, etc. are responsible for environmental degradation
in urban areas. Unmanaged and unplanned urbanization is the major cause
of environment degradation in recent days. People have established cities
and markets in farming lands in the process of urbanization. Deforestation
is the major cause of air pollution, water pollution, etc. It also invites natural
disasters like soil erosion, landslides, floods, etc. Increasing use of vehicles
and rapid growth of industrialization in human residential areas also pollute
natural environment essential for animals and plants. Ultimately, it degrades
the whole natural environment and disturbs environmental balance. Thus, it
is necessary to control unmanaged and unplanned urbanization in order to
conserve environment.

Industrialization

Industrialization is one of the

major causes of environmental

degradation. The rapid growth

in industries, factories, etc.

is industrialization. With the

advancement in science and

technologies, many industries and Fig.

factories are in operation to meet

the various demands of people. 22.3

Industries and factories are essential for economic development of the nation.
But, unplanned and unmanaged rapid growth in industrialization causes
environmental degradation. More natural resources as raw materials are
needed to operate industries. It creates over pressure on natural resources.
Over pressure on natural resources result in degradation of natural
environment. Similarly, the byproducts, sewage, wastage, gases, etc. emitted
from industries pollute environmental components like air, water, soil, etc.
Sound produced from industries or factories is the cause of sound pollution.
Inorganic components like plastics produced from industries pollute land.
Thus, unmanaged industrialization degrades natural environment and hence,
it is necessary to control rapid growth of unplanned industrialization in order
to conserve environment.

Activity 1

Make a visit to an industry or a factory in your locality and study its adverse
effects on environment of the surrounding area. Prepare a short note on the
basis of your study.

270 GREEN Science and Environment Book-7

Fig.Effects of Degradation of Natural Resources

Various living beings and non-living things are natural resources. These
resources are wildlife, vegetation, air, water, soil, minerals, fossil fuel. All living
beings depend on natural resources for their survival and to fulfill their various
needs. Air and water are life components of all kinds of animals and plants
since they cannot survive in the absence of these components. But, excessive
and unmanaged use of natural resources is the major cause of degradation and
depletion of natural resources. At present, increasing population, rapid growth
in urbamzation and industrialization, excessive use of natural resources are
the major causes of creating over pressure on natural resources. Thus, natural
resources are being degraded and destroyed day by day. The degradation and
destruction of natural resources results in environmental degradation and
imbalance among various components of environment. Both biotic and abiotic
components of environment get affected adversely due to the environmental
degradation created by degradation of natural resources. Vegetation, animals
and birds, water resources, air, land, minerals, etc. are adversely affected by
unmanaged human activities.

Vegetation

The totality of all kinds of plants
like trees in the forest, fruit plants,
vegetables, crops, grasses, etc. is
called vegetation. Vegetation is one
of the important natural resources
that provides food and shelter to
all animals. It also provides various
materials to human beings to
conduct various construction works
and to produce various goods from
industries. The excessive use of 22.4
vegetation resource without caring
for its role in environmental balance creates various problems in natural
environment. The major effects of destruction or depletion of vegetation are
given below.

i. Reduction in amount of oxygen and increase of carbon dioxide in atmosphere.

ii. Destruction of rare and expensive plants and medicinal herbs.

iii. Extinction of rare wildlife due to destruction of their habitats.

GREEN Science and Environment Book-7 271

Fig.iv. Disturbance in natural water cycle, drought, acid rain, scanty rain, etc.

v. Occurrence of various natural disasters like soil erosion, landslides, flood, etc.

vi. Adverse effects in agricultural system

vii. Desertification due to disturbance in water cycle.

Thus, it is essential to conserve vegetation to maintain environmental balance
by conserving various components of vegetation.

Animals and Birds

Animals and birds are important
biotic components of environment.
They have great role in maintaing
environmental balance and
ecosystem in nature. Human beings
depend on animals and birds for
various purposes. Human beings
obtain food from animals and birds. 22.5
They tame various animals and
birds like cow, goat, buffalo, poultry, etc. for their benefit. Wild animals and
birds play vital role in maintaining environmental balance. Environmental
degradation results in destruction of various animals and birds due to the
destruction of their habitats. Imbalance in environment creates unfavourable
environment for animals and birds. As a result, there is reduction in the number
of wild animals and birds and it results in imbalance in natural ecosystem.
Imbalance in natural ecosystem is the major cause of disturbance in the food
chain of animals.

Destruction of vegetation results in reduction of herbivores. The number of
carnivores decreases due to the crisis of food in absence of herbivores. In this
way, environmental degradation is the major cause of extinction of various
species of animals and birds due to destruction of their food and habitat.

Activity 2

Make a study of vegetation and various animals and birds in your locality.
Compare the condition of these aspects in the past and present by taking
information from your elders. Prepare a brief report on the basis of your
study by taking the support of your subject teacher.

272 GREEN Science and Environment Book-7

Fig.Water Resource

Water resource is one of the vital
component of environment. Water
bodies like rivers, lakes, ponds,
streams, etc. are major sources of
water required for various purposes
such as drinking, irrigating, cleaning
and washing, industrialization, etc.
Water is essential for agricultural 22.6
activities like livestock farming, fishery, etc. Similarly, we use water resources to
produce hydroelectricity and operate various industries. The excessive use of
water resource without management is the major cause of degradation of water
resources. Various activities of human beings are responsible for destructing
and polluting water resources. Deforestation, excessive use of insecticides and
pesticides for agricultural activities, throwing waste materials, in the water
sources, etc. cause water pollution.

Generally, water resources of city and urban areas are adversely affected by
human activities. Pollution of water resources results in degradation in natural
property of water, destruction of aquatic animals due to pollution in their
habitat, depletion of vegetation due to polluted water, etc. Ultimately, it creates
crisis in fresh and suitable water needed for the survival of animals and plants.
Polluted water is the major cause of outbreaking of various diseases of animals
and plants. Thus, it is essential to conserve water resources in order to maintain
natural condition of water resources for the conservation of environment.

Air

Air is a life component for all living beings as they need air to breathe. Living
beings take in oxygen and throw out carbon dioxide during respiration.
Animals and plants need fresh oxygen for respiration. But, various human
activities are responsible for polluting air. Thus particles and smoke emitted
from various industries and vehicles pollute air of the atmosphere. Polluted
air adversely affects all living beings. Polluted air is also responsible for
outbreaking of various diseases. Pollution in air is also results in degradation
of cultural heritages like statues, inscriptions, monuments, etc. The harmful
gases like sulphur dioxide, nitrous oxide, etc. released from industries and
factories are responsible for acid rain. Acid rain degrades agricultural crops
and other vegetation. Moreover, pollution in air degrades overall natural
quality of environment. Therefore, it is essential to conserve natural condition
of air in order to conserve our environment.

GREEN Science and Environment Book-7 273

Fuel

Fuel is very essential for human beings. It is used to operate various industries,
factories, vehicles, etc. More than that fuel is essential to cook food. Human,
beings use fossil fuel like petrol, diesel, kerosene, coal, etc. But, the sources
of fossil fuels are limited in nature. In this situation, alternative sources of
energy are essential to use in place of fossil fuel. Sunlight is the perpetual
source of energy. Green plants use solar energy to prepare their food. Human
beings use various forest products to fulfil their domestic and industrial needs.
People use firewood as the major source of fuel to cook food. Over pressure on
forests results in environmental degradation. At the same time, degradation in
environment is responsible for destruction of vegetation. It ultimately invites
energy crises. Moreover, destruction of forests is the major cause of various
natural disasters like landslides, soil erosion, flood, etc. It is necessary to use
fossil fuel wisely and economically to conserve environment.

Land

All living beings and non-living things exist on land. Land is the common
home for all animals and plants. Moreover it provides food to all living
beings. The natural condition of soil is very essential for its beneficial use.
But, various human activities like industrialization, use of insecticides and
pesticides, unmanaged agriculture, etc. are responsible for degradation of soil.
Soil pollution ultimately leads to environmental degradation. Water pollution,
air pollution, unmanaged industrialization, deforestation, etc. are the major
causes of land pollution. Thus, environmental degradation is responsible for
degrading the natural quality of land.

Minerals

Minerals are non-renewable natural resources that have great importance for
human beings. The metals, non-metals and their compounds found under the
earth surface are all minerals. Human beings use minerals for various purposes
like extracting gases, metals, fuels, etc. needed for industrialization. Over and
unwise use of minerals results in crisis of these resources. Therefore, it is essential
to use minerals wisely and economically to preserve them for future generations.

Natural Disasters

The extreme and sudden events caused by environmental factors that
affects living beings and damage property are called natural disasters. Some
examples of natural disasters are landslides, flood, earthquake, volcanic

274 GREEN Science and Environment Book-7

Fig. Fig.eruption, hurricanes, tornadoes,
tsunamis, etc. They occur in nature
and human beings cannot stop
the occurrance of these disasters.
But, they can be minimized by
maintaining environmental balance
and conservation of environment.
In this connection, introduction
to earthquake and volcano is
presented with their causes, effects 22.7
and preventive measures.

Earthquake

Earthquake is one of the dangerous
natural disasters that may claim
lives of livings beings and cause
destruction of property. The shaking
of the earth surface resulting from
the sudden release of energy in the
earth's crust is called earthquake.
It is also called quake or tremor or
temblor. Earthquake occurs due to
the vibration of the earth's surface 22.8
that may be left and right or up and down. Nepal is the most sensitive zone
for earthquake. There is the history of many devastating earthquakes in Nepal.
The most devastating earthquakes that occured in Nepal are earthquakes
of 1990 BS (8.3 Richter scale), earthquake of 2045 BS (6.6 Richter scale) and
earthquake of 2072 BS (7.6 Richter scale). These earthquakes claimed many
lives and property.

Causes of earthquake

The major causes of earthquakes are given below:

a. The movement of tectonic plates situated beneath the earth's surface is the
cause of earthquake.

b. Earthquake occurs due to volcanic eruption.

c. Contraction and relaxation of rocks beneath the earth crust results in
earthquake.

d. Explosions during the extraction of minerals under the earth crust is the cause
of earthquake.

GREEN Science and Environment Book-7 275

Fig.Effects of earthquake
a. Earthquake destroys lives and properties.

b. It causes natural disasters like soil erosion, landslide, volcanic eruption, flood,
tsunami, etc.

c. It changes natural structure of land.

d. It degrades environment by polluting land, water and air.

e. It may cause fire by short-circuiting and breaking gas pipelines.

f. It destroys habitats of animals and plants.

g. It destroys water resources.

Preventive measures of earthquake
Earthquake cannot be controlled, but harmful effects of earthquake can be
minimized by the following ways:

a. By constructing strong physical infrastructures like houses, buildings, bridges,
etc.

b. By protecting ourselves in safe and open places during earthquake.

c. By staying away from weak walls, electric poles, tall trees, etc. during
earthquake.

d. By protecting our head under strong support like door frame, table, etc.

e. By switching off electricity to prevent from catching fire during earthquake.

f. By generating awareness programmes regarding in preventive safety
measures of earthquake.

Volcano

A volcano is a rupture in earth's
crust where molten lava, hot ash and
gases from below the earth's crust
escape into the air. The majority of
volcanoes are formed when two of
the earth's plates meet and collide.
Generally, volcanoes occur on the
ocean floor. High temperature of
magma and high pressure on it is
the major cause of volcano. The 22.9
mantle of the earth contains very hot magma (2500°C) and magma always
tries to flow upward due to very high pressure. When hot molten magma gets

276 GREEN Science and Environment Book-7

cracks or weak earth crust, it escapes from it resulting in volcanic eruption.
Volcano is also one of the dangerous natural disasters which may cause great
devastation of lives and properties of the surrounding area.

Causes of Volcano
The major causes of volcano are given below:

a. Shifting of tectonic plates creates cracks on the earth crust and over pressurized
hot molten magma gets outlet through these cracks causing volcanic eruption.

b. The water entering the mantle through the cracks on the earth crust evaporates
and creates pressure. The molten magma flows upwards due to over pressure
and escapes through cracks causing eruption.

Effect of Volcano
The effects of a volcanic eruption are given below.

a. It brings changes in topography (land structure).

b. It claims lives and properties.

c. It damages vegetation and agricultural lands.

d. It causes air pollution, land pollution and water pollution due to the emission
of various materials like ash, gases, etc.

e. It causes tsunami if volcanic eruption occurs near the sea.

f. If causes climate change by adding dust and smoke in the atmosphere.

Activity 3

Make a study of the natural disaster that occurred in your locality and note
down the causes and effects of that disaster. Also, share it with your friends
in your classroom.

Environmental Sanitation

The process of creating clean, healthy and balanced environment around
us is called environmental sanitation. Environmental sanitation is essential
to maintain congenial environment for both animals and plants. Also, it
is necessary to minimize various natural disasters and conserve different
components (air, water, soil, etc.) of the environment. The major way of
environmental sanitation is to control pollutants of environment. Proper
management and disposal of waste materials is essential to control pollution
in environment. Biodegradable and non-biodegradable wastes should
be managed properly in order to keep environment clean and healthy.

GREEN Science and Environment Book-7 277

The most effective technique of maintaining environmental sanitation is
reducing, reusing and recycling of waste materials.

Reduce

Reduction in use of various materials results in production of less waste. Less
waste can be managed easily to maintain environmental sanitation.

Reuse

Reuse of waste materials is one of the effective methods of environmental
sanitation. In this method, biodegradable wastes can be decomposed to
prepare organic manure. Organic manure can be used for organic farming.
Similarly, non-biodegradable wastes can be reused by modifying them into
various items required in our daily life.

Recycle

There are various materials which can be recycled to use them again. Such
materials are papers, plastics, metals, glasses, etc. These materials can be
recycled in factories to prepare various items that can be used again and
again. Recycling of waste materials helps maintain environmental sanitation
by controlling pollution in environment.

Activity 4

Make a list of biodegradable and non-biodegrable materials available in your
surroundings. Discuss the methods of reusing and recycling these materials
among your friends in your classroom.

Efforts on Environmental Conservation

Environment can be conserved by conserving and promoting its various
components. Human being are responsible for conserving environment since
various activities of human beings result in environmental degradation. Also,
human is a wise animal with rationality. Various efforts can be made to save
natural environment with its various biotic and abiotic components. It is our
responsibility to conserve environment for us and our future generations.
Some of the ways that can be adopted for environmental conservation are
generating public awareness, afforestation and protecting forest, wise use
of natural resources environmental sanitation, protection and promotion of
cultural heritages, etc. The brief description of these efforts is presented below.

278 GREEN Science and Environment Book-7

a. Generating Public Awareness

Public awareness is one of the most effective methods of conserving
environment. All people should have knowledge about the importance
of environment for the existence of all living beings and non-living things.
Conserving environment is possible by the effort of all human beings who use
components of environment for various purposes. It is necessary to generate
various awareness programmes in different level to make people aware
about conserving environment. Generally, it is essential to conduct various
awareness programmes related to conservation of environment in local levels.
Environmental education is necessary to make people aware about protecting
and conserving environment.

b. Public Participation

It is not possible to conserve environment by individual effort or effort of few
people. More and more people should be involved in conserving environment.
Thus, it is essential to increase public participation so that it becomes
responsibility of all people to conserve our environment.

c. Integrated Conservation Programmes

The concept of integrated development is one of the effective efforts for
conserving environment. Various developmental works like road construction,
water supply, electrification, etc. can be conducted together by conserving
environmental components. It is helpful to reduce pollution in environment.

d. Conservation of Vegetation and Afforestation

Vegetation is one of the important components of environment responsible
for maintaining environmental balance. It is necessary to conserve vegetation
by conserving forest. Similarly, it is necessary to increase the area of forest by
planting trees in barren and unused land. Green forest helps in maintaining
environmental balance by maintaining water cycle and balance between
oxygen and carbon dioxide.

Environmental Sanitation

There is more pressure on natural resources due to the growth in population.
People use various components of environment and create more waste
materials in environment. Overuse of natural resources and creation of
waste materials results in environmental degradation. Thus, it is necessary to
maintain environmental sanitation to conserve environment. The following
efforts can be made in the local level for environmental sanitation.

GREEN Science and Environment Book-7 279

i. Keeping home and surrounding clean and healthy
ii. Proper management and disposal of waste materials
iii. Conservation of natural resources like water, land, air, vegetation, wildlife,

etc.
iv. Reducing fossil fuels and increasing alternative sources of energy like solar

energy, bio gas, etc.
v. Conducting sanitation and awareness programmes

Protection and Promotion of Cultural Heritages

Cultural heritages are important components of environment. Nepal is rich in
cultural heritage. But, pollution in different levels is responsible for degradation
of cultural heritages. Depletion of cultural heritages results in environmental
degradation. Thus, it is essential to make various efforts in the local level to
conserve and promote various cultural heritages to conserve environment.

Activity 5

Make a list of efforts that have been made in your locality to conserve various
components of environment. Also, discuss it in your classroom.

Government Agencies Involved in Environmental Conservation

Various government agencies are involving in conservation of environment.
Such agencies are ministry of Science, Technology and Environment, Ministry
of Forests and Soil Conservation, Ministry of Education, various departments
related to forest, soil, water, wildlife, etc. They have been conducting various
programmes to control population, reduce pollution, maintain environmental
sanitation, generate public awareness, etc. In this context, a description of the
Ministry of Science, Technology and Environment, and Ministry of Forest and
Soil Conservation is provided.

Ministry of Science, Technology and Environment

The Ministry of Science, Technology and Environment is responsible for
making necessary efforts to conserve environment by managing environmental
problems. It has set certain goals regarding conserving and promoting
environment and acts accordingly. The goals and functions of Ministry of
Science, Technology and Environment are given below:

280 GREEN Science and Environment Book-7

Main Goals

i. To preserve and promote various traditional indigenous technologies of our
country.

ii. To conserve various natural resources like air, water, soil, etc.

iii. To conserve and promote natural and cultural environment for maintaining
environmental balance.

iv. To conduct various research and awareness programmes related to science,
technology and environmental conservation.

v. To encourage people for working in the field of environmental conservation.

Major Function

i. The Ministry of Science, Technology and Environment prepares and
implements various policies, strategies, plans, etc. related to environmental
conservation.

ii. It encourages and develops manpower required to work in the field of
environmental conservation.

iii. It frames and implements pollution control directives.

iv. It conducts various research programmes related to conserving environment.

v. It monitors local, national and international agencies working in the field of
science, technology and environment.

vi. It generates awareness related to environmental conservation and conducts
conferences, seminars, meetings, etc.

vii. It disseminates various information related to environmental conservation
through different electronic media like radio, television, websites and non-
electronic media like newspapers, leaflets, pamphlets, posters, etc.

Ministry of Forest and Soil Conservation

The Ministry of Forest and Soil Conservation has responsibility for conserving
and promoting various resources like land, forest, water, wildlife, vegetation,
etc. The goals and functions of the Ministry of Forest and Soil Conservation
are given below.

Main Goals

i. To prepare and implement polices and strategies for conserving and managing
forests

ii. To conserve vegetation and wildlife

GREEN Science and Environment Book-7 281

iii. To prepare and implement polices for land conservation

iv. To conserve water resources like rivers, watersheds, wetlands, etc.

v. To make polices for wise use of forest products.

vi. To make directives for using valuable medicinal plants and herbs.

Major Functions

i. The Ministry of Forest and Soil Conservation frames various polices, directives,
acts, laws, etc. related to conservation of forest and soil and implement them.

ii. It monitors and evaluates various activities related to forests and soil
conservation.

iii. It conducts research programmes regarding conservation of land, forest
vegetation, etc.

iv. It coordinates with various agencies of different levels working in the field of
forest and soil conservation.

v. It conserves and promotes natural ecosystem.

vi. It prepares and implements national policy regarding soil and forest
conservation.

vii. It conducts various awareness programmes related to conserving natural
resources through electronic and non-electronic media.

Project Work

Make an internet search for finding main goals and major function of the
Ministry of Science, Technology and Environment in the field of environmental
conservation . Prepare a short report on the basis of your research and present
in your classroom.

Key Concepts

1. The disturbance in any aspect of the environment is the cause of environmental
degradation. Environmental degradation refers to the deterioration in any
aspect of environment due to human activities that have adverse effects on
natural environmental degradation.

2. Human beings obtain various materials from forest that are used for various
purposes like construction, making furniture, etc.

3. The act of clearing forest for various purposes like excessive use of forest
timber for construction work, expansion of agricultural land and residential
area, etc. is called deforestation.

282 GREEN Science and Environment Book-7

4. It is necessary to conserve forest resources by afforestation, conducting
awareness programmes, conserving forest plants, grass land and pasture
land, utilizing forest resources wisely, stopping forest fire and prohibiting
haphazard clearing of forest.

5. Urbanization is the process of expanding residential areas or establishing
cities or towns by construction of large buildings in search of modern
facilities.

6. Unmanaged and unplanned urbanization is the major cause of environment
degradation in recent days.

7. The rapid growth in industries, factories, etc. is industrialization.

8. Unmanaged industrialization degrades natural environment and hence, it
is necessary to control rapid growth of unplanned industrialization in order
to conserve environment.

9. All living beings depend on natural resources for their survival and to fulfill
their various needs.

10. The degradation and destruction of natural resources results in
environmental degradation and imbalance among various components of
environment.

11. The totality of all kinds of plants like trees in the forest, fruit plants,
vegetables, crops, grasses, etc. is called vegetation.

12. Environmental degradation is the major cause of extinction of various
species of animals and birds due to destruction of their food and habitat.

13. Deforestation, excessive use of insecticides and pesticides for agricultural
activities, throwing waste materials, in the water sources, etc. causes water
pollution.

14. Water pollution, air pollution, unmanaged industrialization, deforestation,
etc. are the major causes of land pollution.

15. The extreme and sudden events caused by environmental factors that affects
living beings and damage property are called natural disasters.

16. The shaking of the earth surface resulting from the sudden release of energy
in the earth's crust is called earthquake.

17. A volcano is a rupture in earth's crust where molten lava, hot ash and gases
from below the earth's crust escape into the air.

18. High temperature of magma and high pressure on it is the major cause of
volcano.

GREEN Science and Environment Book-7 283

19. The process of creating clean, healthy and balanced environment around us
is called environmental sanitation.

20. The most effective technique of maintaining environmental sanitation is
reducing, reusing and recycling of waste materials.

21. Some of the ways that can be adopted for environmental conservation are
generating public awareness, afforestation and protecting forest, wise use
of natural resources, environmental sanitation, protection and promotion of
cultural heritages, etc.

Exercise

1. Tick (√) the correct statement and cross (×) the incorrect one.
a. The physical world around us is the only environment.

b. Migration of people in unplanned manner causes deforestation.

c. Extinction of various rare plants and animals is the effect of
afforestation.

d. Human activities are responsible for natural disasters.

e. Recycling of waste materials is one of the effective techniques of
environment sanitation.

2. Fill in the blanks using appropriate words.
a. The major effect of deforestation is environment ......................
b. Rapid urbanization causes ...................... pressure on natural resources.
c. Emission of harmful gases from industries is the major cause of
...................... pollution.
d. The ...................... of the earth surface is called earthquake.
e. The Ministry of Science, Technology and Environment is a ......................
agency involved in environment conservation.

3. Answer the following questions:
a. What do you mean by environmental degradation?
b. What is deforestation?

284 GREEN Science and Environment Book-7

c. What is urbanization?
d. Define natural disasters with three examples.
e. What is a tremor? How does it occur?
f. What do you mean by volcanic eruption? What is its major cause?
g. Define environmental sanitation.
h. Differentiate between 'reduce' and 'reuse' of materials.
i. What is public participation? Why is it necessary for environmental

conservation?
j. Name any two government agencies working in the field of

environmental conservation.

4. Write short notes on: b. Vegetation
a. Industrialization d. Fuel
c. Animals and Birds f. Recycle
e. Volcano

5. Mention any five causes of deforestation.

6. How are water resources and air adversely affected by environmental
degradation?

7. Mention any four causes of earthquake. How can we adopt safety
measures during earthquake? Explain briefly.

8. "Natural disasters cannot be controlled totally but we can minimize
their effects." Justify this statement with suitable examples.

9. "Reduce, Reuse and Recycle are the effective techniques of maintaining
environmental sanitation." Explain this statement with appropriate
examples.

10. Mention any five local efforts that have been made to conserve
environment. Explain any one of them briefly.

11. Mention the main goal of the Ministry of Science, Technology and
Environment in the field of conserving environment in the context of
our country.

12. What are the major functions of the Ministry of Forests and Soil
Conservation in Nepal?

GREEN Science and Environment Book-7 285

Environment
UNIT and Sustainable

23 Development

Weighting Distribution (Approximate) Teaching periods : 5 Marks (in %): 1

Before You Begin

The totality of biotic and abiotic components around us is environment.
Environment is the natural world around us where plants and animals
live. Environment consists of physical world as well as biological world.
The earth is the common habitat for all plants and animals. Living
beings get air, water, food, habitat, etc. from the earth. Environment is
made of abiotic and biotic components. The abiotic components of the
environment include sunlight, air, water, soil, temperature, pressure,
rainfall, etc. Similarly, the biotic components of an environment include
differnet types of plants and animals.

Sustainable development refers to the development that lasts long
and does not degrade the environment. Sustainable development is
the development that meets the need of present generation without
compromising the ability of future generations to meet their own needs.

Sustainable development is nature friendly development because it does
not harm the components of natural environment and conserves natural
resources for the use of future generations.

Learning Objectives Syllabus

After completing the study of this unit, students will be able to: • Concepts of Development

i. define environment and explain the concept of • Development and Environment
• Concept of Sustainable
development.
ii. explain the relationship between development and Development
• Nature friendly development
environment.
• Ways for carrying out nature
iii. describe the concept of sustainable development.
friendly developmental
iv. introduce nature friendly development.
v. tell the ways of adopting nature friendly development. activities
vi. mention the efforts of sustainable development that • Efforts for sustainable
development in the context of
can be made in the context of Nepal.
Nepal

Glossary: A dictionary of scientific/technical terms

sustainable : capable of being sustained, able to be used without being completely used
up or destroyed
biodiversity
species : the existence of large number of plants and animals
: the group of closely related organisms which can interbreed freely to
genetic
ecosystem produce fertile offspring
: heritable, relating to or determined by the origin
mutual : the structural, functional and self-sustaining unit made of living beings

and non-living things
: shared between two or more people or groups

286 GREEN Science and Environment Book-7

Environment and Sustainable Development Fig. Fig.

Concept of Development

Development refers to improvement
in economic and social conditions
of a particular area in order to
create wealth and improve people's
lives. In other words, development
is proper management of natural
and human resources for the benefit
of the people. In this sense, the
positive change that take place in a
particular area with the mobilization 23.1
of human resources and natural
resources is development. Development fulfills the needs and requirements
of people, society and the nation. Various development works that are carried
out in our society are constructing buildings, roads, bridges, canals, producing
hydroelectricity, establishing industries and factories, etc. Mobilization of
various natural resources like water, soil, forest products, minerals, etc.
are essential for development. On the one hand, development works are
necessary for people on the other hand, various development works degrade
environment. The use of various natural resources for development destructs
natural resources and pollutes natural environment. Thus, it is necessary to
conduct nature friendly development work for sustainable development.

Development and Environment

Human beings exploit various
natural resources available in the
environment for their benefit.
Various developmental works are
conducted in nature by mobilizing
different resources of the
environment. Thus, environment or
nature is essential for development.
It is necessary to use natural
resources wisely to conduct various 23.2
developmental works in nature.
Unwise and overuse of natural resources degrade environment by inviting
pollutions in various levels. People construct roads for transportation facility.

GREEN Science and Environment Book-7 287

It pollutes air, water, etc. and causes erosion, landslides, etc. Therefore, it is
necessary to carry out developmental works by conserving various aspects
of environment for sustainable development. The development works carried
out without caring for various aspects of environment cause environmental
degradation.Also, environmental degradation adversely affects developmental
works. For example, vehicles plying on the road pollute air and landslides,
flood, etc. damage roads, buildings, etc. Thus, it is necessary to mobilize
various resources for development by conserving environment.

Concept of Sustainable Development

The wise and economic use of natural resources for development is essential
to carry out nature friendly development. Nature friendly development lasts
long without harming environment to a large extent. In this sense, "sustainable
development is development that meets the needs of the present without
compromising the ability of future generations to meet their own needs." In
this sense, sustainable development does not harm environmental components
so that the present condition of environment can be conserved for the future
generations in the same condition.

Sustainable development is a process for meeting human development goals in
a sustainable manner. It is the organizing principle for sustaining finite resources
necessary to provide for the needs of future generations of life on the earth.
Sustainable development does not undermine the integrity, stability and beauty
of various components of natural environment. The principle of sustainable
development suggests us that we can utilize natural resources for various
developmental works, but the natural resources should be conserved in the same
condition for the utilization of future generations as they are now. It means that
sustainable development does not degrade or destruct natural environment.

Sustainable development is based on the following facts:

i. consumption of natural resources with their limits.

ii. realization of interconnections among various components of environment.

iii. equitable distribution of natural resources.

Benefits of Sustainable Development

i. It can be maintained for a long time without harming natural environment.

ii. It does not degrade or pollute environment.

iii. It helps conserve natural resources for future generation.

iv. It does not affect life cycle of living beings in environment.

288 GREEN Science and Environment Book-7

v. It helps maintain environment in the need of time to conserve environment
in this age of urbanization and industrialization. It is essential to adopt the
principles of sustainable development to conserve environment that is being
polluted due to excessive use of natural resources without thinking for future.

Activity 1

Make a study of any one of the developmental activities (road, building,
bridge, etc.) carried out in your locality to find out the use of natural resources
used in this activity and affects of this activity on environment. Prepare a
short report on the basis of your study and share it in your classroom.

Nature-friendly Development

The development which does

not affect nature adversely is

nature-friendly development.

Sustainable development is nature

friendly development as it uses

various components of nature

without harming it. The principle Fig.

of sustainable development is to

conserve the environment for our 23.3
future generations in the same

condition as we have it today. For example, people at present can utilize

forest products for their use by maintaining the same condition of forest by

afforestation and conservation so that environmental pollution and destruction

of forest resource can be stopped. Nature-friendly development does not

destroy habitat and source of food required for all living beings. Sustainable

development is the only nature-friendly or eco-friendly development because it

protects nature, uses natural resources to their bearing capacity, conserve natural

resources for the future use, etc. The necessity of sustainable development is

increasing day by day in the face of growing environmental degradation due

to modernization and industrialization. It is necessary to satisfy human needs

by conserving natural components. Nature-friendly development lasts long

for human benefit and does not affect natural components of environment.

Thus, nature friendly environment is the need of the time.

Ways For Carrying Out Nature-Friendly Development Activities

Nature friendly development activities can be carried out by the following
ways.

GREEN Science and Environment Book-7 289

a. Reducing pollution

Generally, air pollution is the major problem of modern world due to rapid
growth in industrialization. The smoke emitted from factories, industries,
vehicles, etc. pollute atmosphere resulting in environmental degradation.
It is necessary to reduce air pollution with the proper management of
industrialization and transportation for nature friendly development.
Similarly, other types of pollutions like water pollution, land pollution, etc.
should be reduced for nature-friendly development.

b. Conserving water resources and their origins

Water is a life component for all living beings. It is also a basic need for
various developmental works. For example, hydroelectricity is vital element
for various types of developmental works. Water resource is necessary to
generate hydroelectricity, irrigate agricultural land, operate industries, etc. In
the absence of water resources, developemtnal works are not possible. It is
necessary to conserve water resources like river, streams, ponds, watersheds,
wetlands, etc. for nature-friendly environment. We can utilize resources of
water without creating adverse effect on these resources.

c. Conserving land

Land is the common habitat of all living beings. It has great importance for the
development of people, because all developmental activities are conducted on
land. It is necessary to conserve land for sustainable development. We can use
resources from land without creating adverse effect on it. For example, soil of land
can be used for various purposes without creating negative impact or water, air,
forest, etc. Thus, nature friendly development can be carried out by conserving
land and land conservation helps maintain nature friendly development.

Efforts for Sustainable Development in the Context of Nepal

Various activities of human beings are helpful for sustainable development.
For example, saving and promoting various water resources like pond,
well and streams, planting trees and grasses in bare land, etc. The concept
of sustainable development was there in the past, but it has been developed
with scientific principles at present with the alarming danger of environment
degradation due to rapid growth in industrialization. People at present are
more conscious for conserving environment. Different efforts have been made
in different levels for sustainable development. Such efforts that have been
taken for sustainable development in the context of Nepal are given below.
i. Discouraging deforestation and encouraging afforestation.

290 GREEN Science and Environment Book-7

ii. Reduction in consumption of natural resources with their conservation.
iii. Establishment of national parks, wildlife reserves, conservation areas,

community forests, etc.
iv. Local participation in developmental works.
v. Initiation of eco-tourism to conserve various components of nature.
vi. Establishment of various organizations and agencies to work in the field of

conservation of environment.
vii. Conduction of various awareness programmes related to sustainable

development in various levels.
viii. Inclusion of environment science in school, college and university curricula.

Project Work

Make a research of worldwide efforts that have been made in the sector of
sustainable development. You can take help of the internet for your study. Prepare
a short report on the basis of your study and submit it to your subject teacher.

Key Concepts

1. The totality of biotic and abiotic components around us is environment.
Environment is the natural world around us where plants and animals live.
Environment consists of physical world as well as biological world.

2. Sustainable development is the development that meets the need of present
generation without compromising the ability of future generations to meet
their own needs.

3. Development refers to improvement in economic and social conditions of a
particular area in order to create wealth and improve people's lives.

4. The development works carried out without caring for various aspects of
environment cause environmental degradation.

5. The wise and economic use of natural resources for development is essential
to carry out nature friendly development.

6. Sustainable development is development that meets the needs of the present
without compromising the ability of future generations to meet their own
needs

7. The principle of sustainable development suggests that we can utilize natural
resources for various developmental works, but the natural resources should
be conserved in the same condition for the utilization of future generations
as they are now.

8. Sustainable development is the only nature-friendly or eco-friendly
development because it protects nature, uses natural resources to their
bearing capacity, conserve natural resources for future use, etc.

GREEN Science and Environment Book-7 291

Exercise

1. Fill in the blanks with correct word(s).

a. Mobilization of ....................... resources is essential for development.

b. ....................... distribution of natural resources is necessary for
sustainable development.

c. Sustainable development is ....................... friendly development.

d. Nature friendly development does not affect ....................... environment.

e. Various ....................... have been made in Nepal for sustainable
development.

2. Match column A with column B. Column B
Column A Conserving of environment
Sustainable development Conserving of forest
Air pollution Lasts long
Afforestation Environmental degradation
Rationality in using natural resources

3. Answer the following questions:
a. Define development with one example.
b. How are development and environment related to each other? Explain
briefly.
c. What is sustainable development? Why is it necessary?
d. Why is it necessary to reduce pollution for nature friendly development?
e. How does local participation of people work for nature friendly
development?

4. Mention any five benefits of sustainable development.
5. Explain any three ways of carrying out nature friendly development.
6. Make a list of any six development works carried out in your locality

and mention their effects on environment.
7. Mention any eight efforts for sustainable development that have been

made in the context of Nepal.

292 GREEN Science and Environment Book-7

Specification Grid
Science and Environment

Theory

Grade: 7 F.M.: 75
Time: 2 hour 15 minutes P.M.: 30

Subject Areas Units No. of No. of Sub Full (K) (U) (A) (HA) Remarks
questions questions marks 30% 40% 20% 10%

Measurement,
Force and Motion

Simple Machine

Physics Pressure 5 10 25 7.5 10 5 2.5

Energy, Work and
Power

Heat, Light, Sound

Magnet, Electricity

Matter

Mixture

Chemistry Metal and Non- 3 6 15 4.5 6 3 1.5
Metal

Some Useful
Chemicals

Living Beings

Biology Cell and Tissue 3 6 15 4.5 6 3 1.5

Life Processes

The Structure of the
Earth

Geology and Weather and 1 2 5 1.5 2 0 1.5
Astronomy Climate

The Earth and
Space

Environment and
its Balance

Environmental

Environment Degradation and its 3 6 15 4.5 6 3 1.5

Science Conservation

Environment
and Sustainable
Development

Total 15 30 75 22.5 30 14 8.5

Note: There are a total to 15 questions and each question has two sub-questions. The
weighting of the main question is 5 marks and that of each sub-question may be
2 or 3 marks.

All units should be included while making question paper.

Question paper should include the questions to test the Knowledge (K),
Understanding (U), Application (A) and Higher abilities (HA) levels of students.

GREEN Science and Environment Book-7 293

Practical

Grade: 7 F.M.: 25
P.M.: 10
Time: 1 hour 30 minutes
Viva voce
Subject Areas Units Drawing/ Practical Construction of Field (4)
labelling/ work, materials and visit/mini
Physics Measurement, explanation etc. (5) experimentation
Force and Motion project
Chemistry (5) (5) work (6)
Biology Simple Machine
Geology and
Astronomy Pressure

Environment Energy, Work and
Science Power

Heat, Light,
Sound

Magnet,
Electricity

Matter

Mixture

Metal and Non-
Metal

Some Useful
Chemicals

Living Beings

Cell and Tissue

Life Processes

The Structure of
the Earth

Weather and
Climate

The Earth and
Space

Environment and
its Balance

Environmental
Degradation and
its Conservation

Environment
and Sustainable
Development

Note: The pass marks of theoretical exam will be 30 and that of practical exam is 10.

294 GREEN Science and Environment Book-7

Model Question
Science and Environment

Grade: 7 F.M.: 75
Time: 2 hours 15 minutes P.M.: 30

Group A: Physics

1. a. What is measurement? How is the volume of an irregular solid measured? (1+2)
b.
2. a. A car covers a distance of 1200 m in 50 seconds. Calculate the speed of the car. (2)
b.
State the principle of lever. Write any two uses of simple machines. (1+1)
3. a.
Why are studs made on football players' boot? Give reason. A force of 600 N acts on
b.
4. a. the area of 3m2. Calculate the pressure exerted. (1+2)

Write any two differences between potential energy and kinetic energy. A person

completes 2000 J of work in 15 seconds. Calculate his power. (2+1)

Draw a neat and labelled figure showing the structure of laboratory thermometer. (2)

What is meant by irregular reflection of light? Study the given figure and answer

the following questions. (1+1)

i. Name the phenomenon shown in the given figure.

ii. What is the magnitude of ∠NOR? R

PN

50° ?

XY
O

b. Describe an experiment to demonstrate that sound can propagate through a liquid. (3)

5. a. Describe the method of making magnet by single touch method with a neat figure. (3)

b. Write any two differences between series combination and parallel combination of

cells. (2)

Group B: Chemistry

6. a. Draw a neat figure showing the structure of an atom. Write any two differences

between physical change and chemical change. (1+2)

b. Write down the molecular formula of the given compounds. (2)

i. Water ii. Sodium chloride

iii. Carbon dioxide iv. Calcium oxide

7. a. What is a mixture? Write any two uses of mixture. (1+1)

b. Describe an experiment to separate the mixture of sand and camphor by sublimation

process. (3)

8. a. Write any two properties of metals and non-metals each. (1+1)

b. What are chemical fertilizers? Write any two uses of each phenol and dettol. (1+1+1)

GREEN Science and Environment Book-7 295

Group C: Biology

9. a. What are warm-blooded animals? Draw a neat and labelled figure showing the life

b. cycle of frog. (1+2)
10. a.
Write any two differences between monocot and dicot plants. (2)
b.
11. a. Why is cell called the basic unit of life? Write one function of each nucleus and

b. vacuole. (1+1)

Draw a neat and labelled figure showing the structure of a plant cell. (3)

What are life processes? Write any two differences between external respiration and

internal respiration. (1+2)

How does digestion of food occur in stomach? Write in brief. (2)

Group D: Geology and Astronomy

12. a. What are metamorphic rocks? Write any two importance of weather forecasting.
b.
(1+2)

What is solar system? Why is the earth called a planet? Give reason. (1+1)

Group E: Environment Science

13. a. What are national parks? Why should we conserve water resources? Write in any two

b. points. (1+1)
14. a.
b. Describe the role of human beings in environmental balance. (3)

15. a. What is environmental degradation? Write any two effects of earthquake. (1+1)

b. Define environmental sanitation. Write any two goals of Ministry of Science,

Technology and Environment. (1+2)

What is sustainable development? Write any two benefits of sustainable

development. (1+2)

Write any two efforts for sustainable development in context of Nepal. (2)

296 GREEN Science and Environment Book-7