Shubharambha Science & Env 6 -2077 press re

Main Points to Remember

1. The group of the sun and the masses revolving around it is called the solar system.
2. Solar system is made up of planets, satellites, comets, asteroids etc.
3. Eight planets of the solar system are Mercury, Venus, Earth, Mars, Jupiter, Saturn,

Uranus and Neptune.
4. All the planets have different diameters, different periods of rotation and

revolution and different distances from the sun.
5. The Mercury is the smallest and the Jupiter is the largest planet.
6. Comets form tail when they come closer to the sun.
7. The sun is the closest star to the earth and it is the centre of the solar system.
8. Diameter of the sun is about 1392000 km and it is 1.5 x 107 km far away from the earth.
9. The sun causes day and night, brightness of the moon, change in seasons and

water cycle on the earth.
10. The earth is the third closest planet to the sun.
11. The earth takes about 24 hours to complete one round on its axis and 365.25 days

to complete one revolusion in its orbit.
12. The motion of the earth round in its axis is called diurnal motion and that in its

orbit is called annual motion.
13. Diurnal motion is responsible for occurring day and night and annual motion is

responsible for change in season and variation of length of day and night.
14. The moon takes 27.33 days to complete one turn on its axis and the same time is

taken to complete one turn around the earth in its orbit.
15. Mean diameter of the moon is 3476 km.
16. Moon has no water, atmosphere and life.
17. Asteroids are heavenly bodies lie in Mars and Jupiter, are called minor planets.
18. When moon is in between earth and sun, solar eclipse occurs.
19. When earth is in between moon and sun, lunar eclipse occurs.
20. Meteors are heavenly bodies which appear with flashes of light in a moonless night.

PRO J ECTWORK

a. Take a globe representing the earth.
b. Let a source of light representing the sun (table lamp or candle or torch
light)
c. Now darken the room and adjust the things as shown in the figure.
d. Study about day and night by rotating the globe.

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Exercises

1. Fill in the blanks:

a. Diameter of the moon is about …………………… km.

b. Diameter of the sun is about …………………… km.

c. Diameter of the earth is about ………………… km.
d. The distance between the earth and the moon is about ………………….

e. Change in seasons on the earth is caused by the ……………..
2. Match the following:

Earth’s day 27.33 days

Moons’ day 24 hours

Earth’s year 386,000 km
Distance between the sun and the earth 15,00,00,000 km

Distance between the earth and moon 365.25 days
3. Choose the correct answers:

a. The heavenly mass revolves around the planets is:

i. Satellite ii. Comet iii. Meteor iv. Star

b. The path of the earth around the sun is called:

i. Axis ii. Orbit iii. Eclipse iv. Year

c. The duration taken by the moon around the earth is called:

i. Rotation ii. Revolution iii. Day iv. Month

d. The heavenly mass which has tail-like structure is:

i. Planet ii. Satellite iii. Comet iv. Meteor

e. In solar eclipse which lies in the middle:

i. Moon ii. Earth iii. Sun iv. Saturn

4. Answer the following questions:

a. What is the solar system?

b. Mention any five effects of the sun on the earth.

c. What are the earth’s day and earth’s year?
d. Write in short about the sun.

e. What are the planets? Name all the planets.
f. Write in short about the smallest and the biggest planets.

g. Write a short note on the moon, the sun and the earth.

h. There is a very great difference between the size of the moon and the sun
but both of them are seen roughly equal in size in the sky. Why?

i. What are called meteors and meteoroids?

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j. Define solar eclipse with diagram. Write two conditions to occur solar
eclipse.

k. Draw the diagram of lunar eclipse. Write any two conditions required for
lunar eclipse.

5. Write the differences between:

a. The sun and the earth b. The earth and the moon

c. Stars and planets d. The moon and the sun

e. Solar eclipse and lunar eclipse

6. Give reasons:

a. Living things cannot survive on the moon.
b. We cannot survive in the absence of the sun.
c. Living things can survive on the earth.
d. There is no possibility of organism on the Neptune.
e. Lunar eclipse is longer than solar eclipse.
7. Sketch a neat and labelled diagram of the solar system.

8. Answer the following questions on the basis of the given figure:

a. At which place of the earth it is morning?
b. At which place is it day?
c. At which place is it night?
9. Study the diagram and answer the following questions:

a. In which condition of the earth the northern D C
hemisphere has the longest day? B

b. In which condition the northern hemisphere
has equal day and night.

c. In which condition of the earth the northern
hemisphere has cold weather?

A

Glossary

Heavenly body : The body found in space.
Asteroid : A member of solar system which are found between the orbit of

Satellite mars and jupiter and revolve around the sun.
Elliptical : A member of solar system, which revolves around a planet.
Axis : Elongated round
Anticlockwise : The imaginary line which connects north and south poles.
: In the opposite direction of the motion of the hand of the watch.

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20Chapter Environment and its Balance

Learning Outcome Estimated Periods: 12+2

On the completion of this unit, students will be able to:

 introduce and tell the importance of environment.
 introduce and explain biotic and abiotic factors and their inter-relationship.
 describe the use and importance of environmental balance and to contribute

in it.
 describe natural resources their uses and to compare their condition with past.

Introduction to Environment

Environment refers to the condition of external things which are associate with
mankind and their behaviors, activities and development. Air, water, land, forest,
river, houses, plants, animals, etc. are the components of the environment.
Environment acts like a mother, it feeds and nourishes us in the same manner like a
mother does to her children. All the things that are needed to run our life are obtained
from environment. Human and other different creatures need healthy environment in
order to grow and fulfill their necessities. Environment can be studied by dividing it
into two parts:

(i) Natural environment

The environment created without human effort and investment is known as natural
environment. Air, water, land, etc. are components of natural environment.

Natural environment is also known as the god gifted environment. The elements of
the natural environment can be classified into physical and biological factors. Physical
factors refer to the non-living things of the environment. Land, rivers, rivulets, wind, etc.
are the examples of physical factors of environment. Biological factors are the living
things of the environment. Plants, animals, insects, etc. are the examples of the biological
factors of the environment.

(ii) Artificial environment

The environment created by human investment and effort is known as artificial
environment. This type of environment is tangible and intangible. Houses, buildings,
temples, etc. are considered as tangible environment and culture, festivals, traditions,
rites and rituals, etc. are considered as intangible environment.

It is obvious that there is a close relationship between both types of environments to
run a comfortable life for all creatures. One aspect of the environment affects another
aspect therefore, the total formation of all these aspects is called environment.

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Environmental aspect is associated with population, health and other different
philosophical aspects like sociology, anthropology, etc. Population control is the first
step for a balanced environment and balanced environment is the most important
factor for sound health. Therefore, all these three aspects are interrelated with each
other.

Factors of natural evironment
The biotic factors of an environment are the living organisms that contribute to that
environment, particularly plants and animals. Abiotic factors are non-living factors,
like wind, heat and rocks. Together, these systems form a cycle called an ecosystem,
composed of producers, consumers and decomposers. A forest is a particularly vivid
example of this system at work.

Activity 1

To observe various factors of an environment.

Observe a field nearby your school/home. Find out by what the environment is made.
Make a list of abiotic and biotic factors of that environment . Present your report in
your class and discuss how these are interrelated with each other.

Abiotic Factors

Non-living factors including physical factors (light, temperature, water, soil, air)
climatic factors and chemical (pH, salinity, oxygen, CO2) factors are called abiotic
factors. They affect growth and survival of organisms.

Air

Air is a mixture of different gases and the multilayered gaseous envelop above the
earth surface is atmosphere. Air contains nitrogen, oxygen, carbondioxid, inert gases,
water vapour, dust particles, etc. Plants use up carbondioxide during photosynthesis
and give out oxygen to the atmosphere. Animals take oxygen during respiration and
give out carbondioxide. Air also helps in pollination and dispersal of seeds.

Water

Water is raw material for photosynthesis. It plays an important role in fertilization,
pollination and dissemination. Human beings, birds and animals use water to sustain
their lives.

Light

The sun is the major source of energy. It provides light and heat energy which is
essential for living organisms. The plants prepare their food through photosynthesis
in the presence of sunlight. Because of geographical structure, some parts of the
earth receive more solar energy than the other. This cause the difference in climate,
rainfall, productivity of certain locality. Therefore, different types of living organisms
are found in different locality.

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Soil

Soil is a mixture of inorganic minerals (clay, silt and sand), decaying organic matter,
water, air etc. It is the store house of nutrients and it forms the substratum for plants
and animals on land. The food prepared by plants using soil nutrients in turn is
utilized by animals as food.

The soil also contains micro-organisms and chemical elements like nitrogen,
phosphorous and potassium which are essential for the plants. Plants absorb water and
minerals from the soil. So, any disturbance in the composition of soil has direct impact
on plants and animals.

Temperature

It influences the habitat of plants and animals. Plants and animals found in cold climate
differ from that in warm climate. Some birds and animals migrate during extreme hot
and cold climate.

Biotic Factors

All living organisms around the surroundings include biotic factors. They are closely
related and interdependent with abiotic factors. The relationship among plants and
animals can be either positive or negative. The biotic factors of an ecosystem can be
classified into producers, consumers and decomposers.

Abiotic Components Biotic Components

Primary consumers
(Herbivores)

Solar energy Producer Secondary consumers
Water (Autotrophs) (Carnivores,
Air Omnivores)

Nutrients

Decomposer
(Bacteria and Fungi

Autotrophs Heterotrophs

Producers
Producers are those organisms which prepare their food by themselves. Since the
food prepared by them is the nutritional source of other organisms, they are given the
name producers. All green plants, algae, grass, herbs, shrubs and trees are producers.

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Consumers
The organism which depend upon other organisms for food are called consumers.
There are three levels of consumers:
a. Primary consumers:
Organisms which use up producers directly as food are primary consumers. For
example goat, cow, rabbit, deer etc.
b. Secondary consumers
They feed on primary consumers and are carnivores and omnivores. fish, crow, fox,
snake, etc. are secondary consumers.
c. Tertiary consumers
They feed on secondary consumers and are mostly carnivores. For example tiger,
lion, large fish, vulture etc.

Decomposers
Those micro-organisms which break down the complex organic compounds present
in dead plants and animals into simple substances are called decomposers. Such
simple substances mix with soil and utilized by producers as minerals and fertilizers.
For example Bacteria, Fungi, etc.

Activity 2

To observe various biotic factors of an environment
Observe an open place in your school or school ground. Make a list of living organisms
of that place. Categorize them into produces, primary consumers, secondary consumers
and tertiary consumers and show different food chain. Discuss about the food chains
exist in your observation area.

Importance of Environment
Environment is the source to fulfill needs and wants of all creatures. However, the
way of consuming environment is different according to different creatures. They
need air, water, land, light, food, etc. for their survival, growth and development.
All the creatures determine their activities according to status of environment. Man

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needs food, house, clothes, medicines, etc. which he obtains from plants and animals,
these are the components of the environment. Environment fulfills the human needs,
provides the essential goods, improves the economic status, etc.

Rapid population growth causes deforestation, landslide, floods, soil erosion and other
environmental problems. Therefore, rapid growth of population is the main cause of
high pressure upon the environment. Forest, cultural heritages, land, minerals come
under pressure by population growth. It causes invitation of obstacles in life.

Importance of environment can be summerized as:
 It is the main source to fulfill our needs.
 It makes life of living being easy and comfortable.
 It helps to determine our attitude and behaviour.
 It is useful for study and research.
 Appropriate consumption of environmental components improves the national
economy.

Natural Resources

Introduction

Natural resources are free gift of nature. There isn’t any contribution of human being
for its creation. Human contribution is needed for its preservation. Different types
of natural resources are found in different places. The forest, animals and birds,
soil, pastures, minerals, air, water, etc. are the examples of natural resources. Some
of the natural resources are exhausted and some new resources are found. This is a
continuous process. Natural resources can be classified into three parts. They are:

i) Perpetual natural resources

ii) Non-renewable natural resources

iii) Renewable nature resources

Natural Resources

Perpetual Natural Non-renewable Natural Renewable Natural
Resources Resources Resources

- Resources that - Resources that can’t - Resources that can
never finish be refilled. be refilled.

- e.g. solar energy, - Petroleum product, - Plants, animals,
tidal energy, etc. fossil, fuel, etc. soil, etc.

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(i) Perpetual natural resources

The natural resources which never finish even after their regular consumption are
known as perpetual natural resources. Solar energy, tidal energy, etc. are the examples
of it. There should be more use of these resources.

(ii) Non-renewable natural resources

Those natural resources that cannot be produced again after use and are formed after
long process are called non-renewable natural resources. Petroleum products, fossil,
fuel, etc. are the examples of it. It is wise to search the alternative source of these
resources for their minimum use.

(iii) Renewable natural resources

The natural resources that can be produced again or renewed are known as renewable
natural resources. Plants, animals, soil, etc. are the examples of it. There should be
more production of these resources.

Importance of natural resources

No living beings can survive in the absence of natural resources. That is why natural
resources have great importance. The importance of natural resources can be enlisted
in the following points:
 Human needs and demands are fulfilled by utilizing natural resources.
 We obtained food grains like rice, maize, green vegetables, fruits, etc. from

natural resources.
 We can get raw materials like timber to construct our shelter.
 Natural resources help to maintain ecosystem and environmental balance.
 Natural resources help to regulate the season and make the life of creatures

comfortable.
 Natural resources promote the economic status of the nation.

 Natural resources even increase the beauty of the nature.

Comparison of past and present situation of natural resources

Natural resources are indispensible parts of human life. People are fulfilling their
wants and desires using natural resources in different ways. Natural resources
provide shelter to all the creatures in the earth. Birds and animals as well as small
creature depend on natural resources for their survival. For the sustainable use of
natural resources, positive manner in using them is needed. Due to the unfriendly
use of natural resources, life of living creatures is being difficult in the present time.

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The status of natural resources is decreasing in comparison to the past. Human
exploitation and pressure is increasing day by day. Therefore, it is necessary to know
the past and present situation of natural resources.

(i) Vegetation (Trees and plants)

Nepal is rich in geographical diversities. Diversities in topography are special feature
of Nepal. The topography of the mountains, hills and terai is very much different.

Human settlement in the himalayan region is minimal. The resources of this region
are under utilized. So, there is not much difference in the past and present situation
of natural resources in the himalayan region.

Human settlement is more in Hilly region than the himalayan region but trend of
destruction of forest has been increased for cultivation. Trees are being cut down for
firewood and timber. The habitat of animals and birds being destroyed significantly
compared to its position in the past.

The population of the terai region is increasing rapidly in comparison to the past. So,
pressure of population on natural resources is also increasing in the same ratio. The
resources of that area are being used at a faster rate. The number of plants and trees
available in terai and Inner terai are decreasing.

(ii) Animals and birds

Nepal is the country of climatic diversity. The different animals and birds are found
in different climate .There are about 181 kinds of mammals in our country. About
852 species of birds are found here. Similarly, 100 species of reptiles are found here.
About 182 species of fishes are available in our country. Besides, various types of
snakes and tortoises are also found here.

Past Present

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Animals Birds

The number of animals and birds are decreasing in comparison to the past. The large
number of animals, birds and plants like musk deer, lophophorus, pheasant, wild
cock, etc. were found in himalayan region. The condition is totally adverse now. In
the same way large number of doves, swallows, tigers, bears, etc. were found in hilly
region. In the terai region, the large number of gajali bird, hamingo, hornbills, tiger,
rhinoceros, spotted deer, etc. were found. But now these animals and birds are not in
adequate number with us due to our unfriendly activities towards the environment.
For instance, the haphazard cutting of forest is taking place. Due to this, the habitat
of birds and animals has been destroyed. This shows that the important need of today
is to conserve the natural resources and to accept the existence of all creatures.

(iii) Land

Land is an important element of the nature, land is used for shelter and for production
of food. The land was fertile in the past and it was free from pollution. There wasn’t
any break in terrestrial ecosystem. But, due to the growth of population, the use of
land has increased in comparison to the past. Due to the cultivation in slope and steep
lands, large amount of soil has been transported by rain, water and soil erosion is
taking place. Nowadays, farmers use different chemical fertilizers and pesticides and
insecticides to increase the production but it has destroyed the quality of the land and
has made the production low in comparison to the past instead of increasing.

Human settlements have increased in urban areas. Industries, factories, roads and
underground building constructions have been increasing. This has caused more
pressure on land. Cultivable land has been decreasing. It is a fact that the conservation
of land is the conservation of all species of plants and animals.

Blooming Science & Environment Book 6 211

Past Present
(iv) Water
Water is an indispensable natural resource for all. Water is useful for the existence of
all species and for their overall development. Water resources can be used to run the
industries, to generate electricity for irrigation, tourism, etc. It helps to improve the
economic status of the country.

Past Present
Due to the rapid population growth, demand for water has increased and has been
started to be misused. The sources of water are getting dry one after another due to
environmental degradation in their surroundings.Therefore, life is being difficult day
by day. Similarly direct disposal of solid and liquid wastes to the source of water has
polluted the water. The problems of drinking water is observed in urban areas than
remote areas.
The situation of water was not like this in the past. There was no population pressure
on water resources because human settlements were not dense like today.
(v) Minerals
Minerals are the important property of Nepal. Among them copper, iron, gold, zinc,
tin, lead, mica, limestone, natural gas, marble, etc. are important. The condition of
minerals was very good in past. They were used to make roofs of temples and places

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of that time. Similarly, metallic coins were under circulation during those time. This
shows that minerals were used since ancient time in Nepal. But most of the minerals
have not been used until now. Minerals should be brought under use to improve the
economic condition of the country.

(vi) Pastures
Open fields, grazing lands, grasslands, etc. are called pastures. There were many
pastures that existed in the past. They were used for grazing cattles. With the
increment of population, the number of cattle is increasing but the pastures are used
for cultivable land. Then problems such as deforestation and denudation of hill
have started to appear. There were pasture lands in all three regions in the past but
now they have been destroyed and used for the construction of buildings for health
centres, hospitals, schools, governmental offices, etc. It is hard to find pasture land
at present in Nepal.

Past Present

Environmental Balance

All living and non-living things live together in harmony within the environment.
Man, birds and animals, green vegetation and other living creatures are the
indispensable components of the environment. Similarly, air, water, soil, light and
other non-living things are also the important components of the environment. Thus,
the inter-relationship between living and non-living things is to be maintained. It
keeps the environment balanced. One co-operates with the other. If there is some
change in the ecosystem, the environment gets imbalanced. The survival of many

Blooming Science & Environment Book 6 213

living creatures become difficult. Some creatures being to disappear. Some creatures
feel difficult for their growth, development and survival. It causes degradation in
the environment. Everything gets disturbed after the environmental degradation.
Hence, the environment should be conserved. The population should be managed to
conserve the environment.

The over exploitation of forest, land, water, minerals, etc. should be avoided. So, the
environment should be kept neat, clean, green and healthy.

The ecosystem continues in the environment. So, it is necessary to use proper ratio
of goods in the environment. It keeps the environment balanced. Population should
be managed to keep the environment balanced. Proper steps need to be taken in time
for population management. It is necessary to develop the awareness among public.
Similarly, natural resources should be used rationally. Besides, our surrounding
creatures, vegetation and physical things should be conserved. These activities keep
the balance in the environment. Healthy environment helps the living beings for
survival, growth and development.

Major consequences of the disturbance in the environmental balance are:

(i) Scarcity of Natural resources, (ii) Health Hazard,

(iii) Greenhouse Effect, (iv) Global Warming, and

(v) Depletion of ozone layer

Importance of the Environmental Balance:

By now it should have been clear that air, water, land, light and other environmental
components are necessary for the survival of living beings. We should ensure that
even non-living things are equally important for our survival. Infact, all living and
non-living things exist in harmony and inter dependence. Plants depend on land,
water, air, sun for their growth and nourishment. Animals depend on plants and human
beings depend on plants and animals both. Each of them is linked with other. If the
link is broken, there will be topsyturvy. The interdependence between living and
non-living things keeps the environment in balance. If imbalance is created, all the
components are badly affected.Many things disappear. So, conservation of animals,
vegetation and physical objects is important to keep the environmental balance.

Main Points to Remember

1. Environment refers to the condition of external things which are associated
with mankind and their behaviors, activities and development.

2. There are two types of environment. They are (i) Natural environment (ii)
Artificial environment.

3. The environment created without human effort and investment is known as
natural environment.

4. The environment created by human investment and effort is known as
artificial environment.

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5. Natural resources are free gift of nature. They are of three types; (i) Perpetual
natural resources (ii) Non-renewable resources and (iii) Renewable resources.

6. The living things like plants and animals are biotic factors.

7. The things like soil, minerals, heat, light etc. are abiotic factors.

8. There should be a balance between population growth and environmental
resources to create healthy life.

PRO J ECTWORK

Visit a nearby community forest with your teacher or parents. take some interviews
with the senior members of the community to compare the past and present status of
vegetation, pasture and wildlife. Make a report and submit to your teacher.

Exercises

1. Fill in the blanks.

a. Environment acts like a ........................
b. There are two types of environment. They are natural and ........................

environment.
c. Plants and ............................. are biotic factors.
d. There should be a ........................in environment for healthy life.
e. Forest, Land, Water and animals are ........................ resources.
2. Write true or False.

a. Non-renewable resources can be refilled.
b. Buildings are part of artificial environment.
c. Humidity is an abiotic factor.
d. Environment is a father to feed its components.
e. The forest of terai is destroyed randomly in comparison to hilly region.
3. Write short notes on.

i. Importance of environment ii. Abiotic factors

iii. Natural resources iv. Factors of environmental balance

4. Match the following

Flora and fauna Perpetual source

Water part of environment
Plants natural resource
Tides biotic factor

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5. Answer these questions

a. What is environment?
b. Define biotic and abiotic factors.
c. What is environmental balance? Why is it important?
d. How can we say the environment is a mother?
e. What are natural resources? Give examples.
f. What are two types of environment?
g. What result is obtained by comparative study of natural resources at

present and past? What do you suggest to save the natural resources?
h. Write the consequences of environmental imbalance.
i. What are the factors of environmental balance.
j. Distinguish between renewable and non-renewable natural resources.
k. Distinguish between biotic and abiotic factors.

Glossary

pollute : make dirty

converse : save, keep

productivity : fertility power

migrate : move away to another place

degradation : decline in status, decline state

urbanization : change of a rural area to a town area, formation of towns and
cities

exploit : use selfishly

rational : able to reason

immigration : coming to live in a country

garbage : waste material, rubbish

deforestation : destruction of forest

census : official counting of people

pollutant : a harmful chemical or waste substance which makes pollution

industrialization : having many well developed industries

degrade : being declining state

fertility : being able to produce much, productivity

migration : moving from one place to another

migration : leaving one’s own country and settling in another

conservation : preservation, protection

obstruct : to stop, to block

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21Chapter Environmental Degradation
and Its Conservation

Learning Outcome

Estimated Periods: 14 + 5

On the completion of this unit, students will be able to:

 tell the meaning of environmental degradation and describe its causes.
 tell the causes and safety measures of disasters (flood, landslide, soil erosion and

fire)
 realize the need of environmental conservation and to participate in it.
 introduce conservation area of Nepal.
 conduct conservation relates activities in school and community.

Environmental Degradation

The environment refers to our surroundings. Human beings are also a component
of the environment. They do different kinds of work for their livelihoods. The
environment is affected by human activities. Shortage of land for housing and
cultivation, shortage of firewood, timber and green grass are observed due to
population growth. Similarly, medicinal herbs are disappearing and the problem of
water shortage for drinking, irrigation has begun to appear.

Natural resources are over used due to population growth. Excessive pressure on
natural resources causes environmental degradation. So, the problem of floods,
landslides, soil erosion occurs. Deforestation and depletion of habitat of wild birds
and animals are taking place. Over use of natural resources has created imbalance
in the environment. It disturbs the life of man, birds, animals and overall ecosystem.

The reduction in quality and quantity of any component of the environment is
generally called environment degradation.

Environmental Degradation

Change in quantity of Change in quality of
environment resources. environment resources

Fig: Concept of Environment Degradation

Environment degradation can be defined as any alteration in the composition or state
of environment which directly and indirectly causes harm to us.

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Natural disaster and preventive measures

Earthquake, landslide, flood, soil erosion storm etc are most common natural
disasters. They damage properties, lives, injure people as well as affect the status of
our environment. They can occur at any place at any moment. It is one of the facts
which causes decrement in population.

Natural disasters are extreme, sudden events caused by environmental factors that
injures people and damage property. The natural disaster can cause great lost of
property, lives and also affects other living things.

Environmental degradation refers to the disturbance and fragmentation of original
quality of the environment. Natural calamities like flood, landslide, soil erosion,
disappearance of plants and animals, etc. cause environmental degradation. The
main cause of environmental degradation is rapid growth of population. Some of the
causes of environmental degradation are described below.

Causes of Environmental Degradation (c) Landslide
(a) Deforestation (b) Flood (f) Pollution
(d) Soil erosion (e) Fire

(a) Deforestation

Deforestation is related to the process of
destroying the forest. Different types of
means and resources are found in the forest.
Destruction of the forest is the main cause of
scarcity of firewood, wood, medicinal herbs,
grass leaves, etc. The effects of disappearance
of these elements are directly associated with
human being because their activities are
responsible for its destruction. People use forest products excessively to fulfill their
wants and desires. Hill and mountains have been naked due to deforestation. People
have established big settlement destroying the forest areas.

On the other hand, when forests are destroyed, water resources start to dry up and
human life becomes very hard. Deforestation causes carbon dioxide gas to increase
in the atmosphere. Oxygen in the air will be diminished. This will result in change in
the temperature of atmosphere. It also hinders regularity of the season. Consequently,
it results into climate change.

Effects of Deforestation
a. Scarcity of firewood, grass, medicinal herbs, etc.
b. Change in the temperature of atmosphere
c. Natural calamities

d. Disappearance of wild life

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Activity

Observe the forest of your locality and answer these questions.
(a) Write any three advantages of forest.
(b) Write any three causes of deforestation.
(c) Write any three efforts on forest conservation.

(b) Flood

Nepal is a mountainous country. Most part of the land in hilly areas has steep slope. It
makes gorge in slopes. The rain transports soil from slopes and fills the beds of rivers
and rivulets depositing those soil, sand, stones, etc. Thus, it causes floods in rivers
and rivulets. The source of water and watersheds fail to keep water in them after a
long heavy rainfall. The surplus water mixes in rivers and rivulets and causes floods.

Floods is the overflow of water from rivers and rivulets and also streams into nearby
lands.

Some of the effects from floods are as follows:

Floods destroy residential area, cultivation and fertile land, etc. It sometimes sweeps out
the whole settlements. Such types of natural events are found in different places in our
country.

Floods have sunk the village areas and houses in town in rainy season. Many people
have become homeless. It destroys a lot of wealth and property and also life.

Various problems are caused by it. These problems destroy different aspects of
environment. In this way it degrades the environment.

Preventive measures

Preventive methods of flood differ from location to location. Basically, the following
methods are employed to prevent flooding.

1. By constructing the banks on the riverside, flood area, etc.

2. By planting trees on both the sides of water resources. In the water resources
catchment area, no one should be allowed to take out stones from building or to cut
trees.

3. By making a proper drainage system for the community.

Blooming Science & Environment Book 6 219

(c) Landslides

Any part of land that slides down is
known as landslide. There are two major
causes for landslides: natural and man
made. The weak geology, steep slopes,
maximum relief, excessive rainfall, etc.
cause landslide. These are natural causes.
Deforestation, uncontrolled grazing
of livestock, unscientific farming, and
cultivation on the marginal land and
steep slopes are man-made causes.

Landslide can be defined as the downward slide of land, especially on hill slopes.

Effects of landslides are as follows:
 The landslide deposits soil, sand and stones in rivers and rivulets. It stops the

flow of sources of water. As a result, sources of water change its way to flow.
The over flow of water takes the form of flood. It destroys the wealth and life
also.
 The landslide covers cultivable land. It deposits and mixes stones, pebbles, sand,
etc. in alluvial soil. It decreases agricultural production.
 The landslide also destroys the forest. It covers small plants. It can also fall
down big trees and plants.
 The landslide destroys the situation of residential area, livestock and even the
sources of water.
 The landslide also destroys the original natural state in different places. It affects
the land, water and vegetation negatively. It degrades the ecological balance of
its surrounding areas.
 When the natural surrounding is degraded, it affects the other aspects of
environment. It degrades the entire natural environment.

Preventive measures

A landslide is a destructive natural disaster, therefore, it should also be controlled.
Some preventive measures are given below which can help to control the landslide
to a little or major extent.

1. Destruction of forest and forest products should be discouraged.

2. Plantation of trees should be encouraged in the bare land deforested areas.

3. Plants and grass should be grown at the boundary of the fields to protect the
fertile soil from erosion.

220 Blooming Science & Environment Book 6

4. Terrace land farming should be encouraged to check the current of water flowing.

5. Overgrazing of many cattle at a particular place should be stopped.

6. Barrages should be made on land.

(d) Soil Erosion

The process of transporting of the upper
crust of the earth by rainwater, rivers and
rivulets is known as soil erosion. It destroys
the fertility of land. Soil erosion has been
the critical problem in Nepal. Millions of
tons of fertile top soil is transported by the
rivers, rivulets and ultimately deposited to
the ocean. It causes decline in agricultural
production.

Soil erosion occurs if there is heavy rainfall, heavy water current, naked land and
steep slope.

Soil erosion is the destruction and carrying away of the layer of soil due to natural
and human activities.

Some of the reasons for soil erosion are as follows:
 Having more steep slopes
 Farming in steep slopes
 The uncontrolled deforestation
 The uncontrolled grazing of livestock

 Improper construction of road, dam and other infrastructures

Soil erosion occurs more in our country due to ecological topography of the country.
Various problems are created by soil erosion in our country. It has polluted the
environment.

The effects from soil erosion are as follows:
 Soil starts becoming loose due to soil erosion. The roots of plants start surfacing.

It harms their growth and development.
 Soil erosion transports the alluvial soil. The soil becomes weak when it rains.
 Transported soil, stones and sand are deposited in river, ponds, lakes when soil

erosion occurs.
 It pollutes the water due to transporting of soil in the source of water.
 The productivity of land decreases if the soil erosion passes through it regularly.

Agricultural production decreases as the quality of the soil is degraded.

Blooming Science & Environment Book 6 221

Soil Conservation

Use of soil in a planned way is called soil
conservation. Soil is the basic foundation
from which plants, animals and living
beings can get shelter, food, etc. In a hilly
region and flood effect areas, different
methods can be implemented for soil
conservation. Here are some suggestions
for soil conservation.

1. Protection of plants and forests help in soil conservation. Plants prevent soil
erosion. A policy on private forest areas, community forest areas, etc. should be
implemented practically so that it helps in soil conservation in a community.

2. It is advisable to plant trees in the borders of private land areas, which prevents
soil from erosion during rainfall.

3. Afforestation projects should be implemented in barren lands and hills. This
prevents soil erosion, landslides and enhances the fertility of soil, increases the
rainfall and protects and nearby rivers or water source from flooding.

4. Farmers in the hilly region should be encouraged in horticulture (farming fruit
trees).

5. Farmers of the hilly region should be educated in terrace farming. Awareness in
terrace farming helps in protection of fertile soil.

6. Human generated activities such as overgrazing by farm animals, uncontrolled
cutting-down of trees, etc. should be controlled.

(e) Fire

Fire can burn out of control in areas of forest
or bush land especially in dry seasons. Fires
are caused by lightning, sparks of electricity
or careless of people. Wind may blow a bush
fire to areas where people live. It can be as
dangerous as other natural calamities if it is
not controlled properly and timely.

The most common hazard in forests is forest fire. Forest fires are as old as the forests
themselves. They pose a threat not only to the forest wealth but also to the entire
regime to animals and plants seriously.

Some of the preventive measures that can be applied are listed below:

a. We must put out the fire after use.

b. Never throw the match box and sticks carelessly.

222 Blooming Science & Environment Book 6

c. We should keep the flammable materials like kerosene, petrol, diesel in safe
place, not near sources of fire.

d. We should not play with fire when wind is blowing.

e. We should not be careless while using fire crackers during festivals.

Activity

Study any one natural calamity like flood or landslide or soil erosion in
your area and write:

(a) Where it occured
(b) Causes, effects and measures for control

Effects of Environmental Degradation

The environmental degradation affects the natural resources. It becomes difficult to

survive for the people, birds, animals and other living creatures. Their wants cannot

be easily fulfilled. The interrelationship among the various things in nature is also

disturbed and causes environmental imbalance. The vegetation is badly affected. It
affects the climate, animals, water resource, land, etc. Lastly, it affects the people
directly or indirectly. The main effects caused by the environmental degradation are
given as follows:

1. Depletion of vegetation 2. Extinction of birds and animals

3. Shortage of water resources 4. Shortage of fuel

5. The change in weather 6. Adverse effect on health

7. Deterioration/Preservation of cultural heritage 8. Desertification

Methods of Conservation and Promotion of the Environment

Natural resources and cultural heritage are of great importance. They should be
utilised properly and wisely. They should be conserved and promoted. The various
aspects of the environment should not be polluted. The environment should be kept
pure and clean. Therefore, environment should be conserved and promoted.

Environmental conservation means preserving the natural resources and making
their rational use for human benefit.

Importance of environmental conservation
 Maintenance of ecosystem
 Preservation of biodiversity
 Creation of healthy environment
 Preservation of cultural heritage

Blooming Science & Environment Book 6 223

The following are the measures to conserve and promote the environment
i. Conservation of forests
ii. Conservation of wild life
iii. Water conservation
iv. Soil conservation
v. Pollution control
vi. Environmental sanitation
vii. Preservation of cultural heritage

Activity

Observe the condition of cleanliness of your school surrounding. Prepare a
report mentioning its condition and control measures. Also organise a cleaning
campaign of your school surrounding with the help of your teacher.

Wildlife Conservation

Forest is the natural habitat of wild animals. There are many different varities of wild
animals found in different regions of our country.

The increase in population has gradual effect on wildlife. Migration of people from
mountain to terai region caused the effect on wildlife. Forests have been destroyed
for human settlement and agriculture. Such activities have led the wild animals in
danger. As a result, wild animals like single-horned rhinoceros, tiger, crocodile, black
buck etc. are disappearing. To control such activities, government has established
several national parks and wildlife reserve. The major purpose of establishing
national parks and wildlife reserves is to conserve wild animals, birds, and their
natural surroundings and to conserve gene pool.

The following steps should be taken to conserve wildlife.

1. Habitat Preservation

Preserving the habitat of wildlife helps in their conservation. Preventing deforestation
is an important method of habitat preservation. Setting up national parks, creating
wildlife reserves, by setting aside permanent protected areas where animals can
live and breed in their natural habitat, is another method. Planting new forests
provide shelter and food for wildlife. Protection of wild animals should be done. For
this purpose, national parks and wildlife reserves should be set up.

In Nepal, there are a large number of wildlife reserves set up by government for the
conservation of wildlife.

224 Blooming Science & Environment Book 6

2. Hunting Regulations

Government regulations relating to hunting and their effective implementation, is
very important for wildlife conservation. The hunting of endangered species is
completely banned. In Nepal, though the hunting is banned, animals are regularly
killed for their skin, the bones, etc. Effective implementation of such laws is,
therefore, of extreme importance. Musk deer has been hunted for centuries. Its musk
is used in perfumes and fetches a lot of money in illegal trade. Therefore, proper
laws and their effective implementation for forbidding hunting should be enforced.
Hunting and illegal trade should be checked and should be made punishable.

3. People Awareness

To create an awareness among people about the importance of animals in nature,
publicity, such as postering and in other communication media like radio, television
should be done.

Economic importance of wildlife

The skin of some animals like cow, buffalo, calf, crocodile and snakes are used for
making leather. The hide of such dead animals is made into fine leather which is used
for making clothes, shoes, belts, bags etc. The skin and bones of animals fetch large
amounts of money.

The tusks of male elephants provide the expensive ivory. It issued for making
decorative pieces.

Protected areas in Nepal

Nepal’s diverse terrain and climate pattern gives rise to ecosystems that range from
subtropical jungles in the low land terai to arctic himalayan highlands. There are 12
national parks, one wildlife reserves, six conservation areas, one hunting reserve
including 11 buffer zone areas in an around protected area, covering a total of
28,998.67 sq. km. The total protected areas make approximately 20 per cent of the
total land area of the country.

a. National Parks

A National park is a large area of land which is protected by the government because
of its natural beauty, plants or animals, in which the public can usually visit. It is
the area separated for the conservation of natural resources, wildlife and plants.
Management of national park conserves the encironment of the place and use the
natural resources as denoted. There are ten national parks established in different
parts of Nepal. Short description of national parks is given below in the table.

Blooming Science & Environment Book 6 225

S.N Name of Area Establish Location Common animals
National in in and plants found
Park
sq.km. Tiger, bear, leopard,
1. Chitwan python, one-horned,
National 932 1973 AD Chitwan, rhinoceros, peacock,
Park (2030 Makwanpur & sal, sisoo, balsam,
BS) Parsa etc.
Kasturi, thar, ghoral,
2. Sagarmatha 1148 19 July Solukhumbu jharal, lophophorus,
kalij, himkukhura,
National 1976 AD gobre sallo,
bhojpata, dhupi,
park (2032 rhododendron,
etc.
BS) Leopard, red panda,
himalayan bear, thar,
3. Langtang 1710 1976 AD Rasuwa, ghoral, khotesalla,
national (2032 Nuwakot kharsu,
Park BS) and rhododendron, fir,
Sindhupalchok birch, etc.
Himalayan bear,
4. Rara 106 1976 AD Mugu kasturi, gobre sallo,
fir, oakm bircg, etc.
National (2032 and Himalayan leopard,
tibetan hare, varities
Park BS) Jumla of birds, himalayan
like rhododendron,
5. She- 3555 1984 AD Dolpa juniper, himalayan
plants, brich, etc.
phoksundo (2040 and

National Park BS) Mugu

226 Blooming Science & Environment Book 6

6. Khaptad 225 1984 AD Bajhang, Bajura Kasturi, ghoral,
(2042 Doti, and leopard, wild
National Park BS) Achham dog, red, monkey,
danphe, munal, oak,
7. Bardiya 968 1988AD Bardiya pine, etc.
(2045 Bengal tiger,
National Park BS) Sankhuwasabha leopard,
and black deer, spotted
8. Makalu 1500 1992 AD Solukhumbhu dear, wild elephant,
(2049 Kathmandu, varities
Barun BS) Nuwakot and of birds sal, sisoo,
2002 AD Sindhupalchok grassland, etc.
National Park Banke, kasturi, ghoral,
12 July Salyan himalayan, thar,
9. Shivapuri 159 2010 AD and rhododendron,
(2067 Dang juniper, etc.
Nagarjun BS) Spotted deer,
Kanchanpur leopard,etc.
National Park 2017AD
Parsa, Bara and Bengal tiger,
10. Banke 550 2017 AD Makwanpur leopard,
black deer, spotted
National Park dear, wild elephant,
varities of birds sal,
11. Shuklaphanta 305 sisoo, grassland, etc.
National Wild elephant,
Park red tiger, leopard
antelope, spotted
12. Parsa 637 deer, etc.
Wild elephant,
National Park antilope and various
birds.

Blooming Science & Environment Book 6 227

b. Wildlife Reserves

A wildlife reserve is an area of land that is protected and managed inorder to
preserve a particular type of habitat and its flora and fauna which are offer rare.
Basically reserves are the areas separated for the conservation of wild animals
and birds. There is only one i.e. Koshitappu wildlife reserve in Nepal.

Koshitappu Wildlife Reserve

Koshi Tappu Wildlife Reserve is a protected area in the eastern terai of Nepal.
It is located in Sunsari, Saptari and udayapur districk in the flood plain of the
Sapta Koshi river. its area is 175 square Kilometre and established in 1976
AD. various plants like eel grass, catechu, kapok, etc. and various animals
like asian elephant , wild boar, spotted deer, water buffalo, watercock, black-
headed cuckooshrike, etc are found in this reserve.

c. Hunting Reserves

A hunting reserve is a large area of land where people are allowed to hunt
the wild animals in a controlled way. The only hunting reserve in Nepal is
Dhorpatan Hunting Reserve.

It is located in the Baglung, Myagdi and Rukum districts. It covers an area of
1325 sq.km and established in 1987 AD. It is the habitat of many mammals and
birds like snow leopards, musk deer, red panda, bluesheep, koklass pheasaw,
cheer pheasant, impeyan pheasnat, etc.

d. Conservation Areas
A conservation area is an area of notable environment which is protected by

law against undesirable charges. The conservation area is established for the
biodiversity conservation of particular area. There are six conservation areas
established in Nepal. They are:
i. Annapurna Conservation Area ii. Kanchanjunga Conservation Area
iii. Blackbuck Conservation Area iv. Api Nampa Conservation Area
v. Gaurishankar Conservation Area

Main Points to Remember

1. The disturbance of environmental balance is known as environmental
degradation.

2. Environmental degradation means deforestation, flood, landslide, soil erosion
and different types of pollution.

3. Natural disaster are extreme, sudden events caused by environmental factors
that injures people and damages property.

4. The overflow of water in the rivers and rivulets in rainy season due to heavy
rainfall is called flood.

5. The falling of land due to regular flowing of water is called landslide.
6. The process of transporting of the upper crust of the earth by rain water, river

and rivulets is called soil erosion.

228 Blooming Science & Environment Book 6

7. Fires can burn out of control in areas of forest or bush land mainly in dry
seasons.

8. The conservation areas help to conserve wild animals, birds and vegetation.
9. The protection of land, water and wildlife from being destroyed is called

environmental conservation.
10. There are 12 national parks, 6 conservation areas and 1 wildlife reserve and 1

hunting reserve in Nepal to conserve wild-lives.

PRO J ECTWORK

1. Write the script of a drama about environmental degradation, its impacts and
conservation. Perform this drama in your classroom to increase the awarenessof
the people and to increase the public participation in conservation work. if
possible perform a best drama by your class in your school or community nearby
your school.
2. Looking at the possibilities your teacher will organise a field visit of one
protected area nearby you. Observe various aspects of the protected area and
write a report on it. Submit the report to your teacher.

Exercises

1. Fill in the blanks

a. By planting trees around the water resources, the .........................does not
dry.

b. The protection of land from being destroyed is called .........................
conservation.

c. Landslide occurs due to .........................
d. .........................destroys our cultural heritage.
e. Environmental degradation destroys vegetation, birds and .........................
2. Write true or false

a. The forest protects land from flood and landslide.
b. Household waste should be deposited in the ditch at a particular place.
c. Deforestation is the cause of natural disaster.
d. Environmental degradation destroys our cultural heritage.
e. Landslide occurs due to air pollution.
3. Match the following

Plantation of trees Desert

Public awareness natural disaster

Fire source of fuel
Firewood environmental cleanliness

Area with no plants and animals control of flood and landslide

Blooming Science & Environment Book 6 229

4. Write notes on

a. Conservation of environment b. Soil erosion
c. Conservation areas d. Natural disasters
e. National Parks
5. Answer these questions:

a. What is environmental degradation?
b. What kind of effect is there with decline in environment?
c. What are conservation areas? Name them.
d. Write the various methods used for soil protection
e. What are natural disasters?
f. What is landslide? Write its causes.
g. How can you be safe from fire?
h. What are the main importances of environmental conservation?
i. How can you play a role to conserve the environment in your community?
j. What is environmental conservation?
k. What is a natural disaster? Write cause, effect and preventive measures of

flood, fire and landslide.

l. What are wildlife reserves?

6. Write the situation of environment and measures of its conservation
around your house. What should we do to improve the environment in our
locality?

Glossary

Calamities : disasters

malnutrition : condition caused by not getting proper amount of food.

Extinction : disappearance

Barren : naked, unprofitable

endangered : put in danger

habitat : living place of animals and plants

tombs : monuments where dead bodies are buried

Conservation : protection

Organisms : living beings

Territory : land

Residence : home

Cope with : manage successfully

Refuse : waste material

230 Blooming Science & Environment Book 6

22Chapter Environment and Sustainable
Development

Learning Outcome Estimated Periods: 10+2

On the completion of this unit, students will be able to:
 tell the introduction and importance of sustainable development.
 explain the relation of population environment and development.
 describe local efforts on substainable development.

Sustainable development

Development activities should not be beyond the capacity of environmental
resources. People should not consume the resources excessively in order to meet
their needs. If over exploitation of resources takes place, it brings adverse effect
on environment. It makes the life of living organisms difficult. Realizing this very
fact, the concept of sustainable development is initiated. It helps to solve the
environmental problems, which carrying development activities.

Sustainable development is based on the principle of long-term vision. It helps
for the conservation of resources for the future generation with the fulfillment of
the needs of present generation. Environmentalists broadly argue in favour of
sustainable development. They focus for the pattern of living that conserves the
habitat, non-renewable resources and the increased use of renewable resources so
that the earth’s eco-system can be maintained.

The concept of sustainable development was introduced by the Brunt land
Commission in 1987 A.D. This commission has defined sustainable development
as “a process in which the exploitation of resources, the direction of investment
and the orientation of technological development and institutional change meet
the needs of the present generation without compromising the ability of future
generations to meet their needs.”

Sustainable development encourages to have economic advantage by the rational
use of resources. It improves the living standard of the people. Though the
resources don’t have direct utility, they should be preserved without disturbing
their quantitative and qualitative aspects. Emphasis should be given for the long-
term preservation of the resources. Sustainable development, in this way, brings
improvement in the important aspects related with human life like health, education,
agriculture, social paradigm, tourism, etc.

Blooming Science & Environment Book 6 231

Reduction in Appropriate Proper
excessive use of management of management of
chemical fertilizer agricultural land water resources

Proper management Balanced Sustainable
of population environment development

Use of eco-friendly Conservation and Public participation
technology rational use of in all levels of

natural resources development activities.

Importance of Sustainable Development

Sustainable development is essential for environmental conservation. The
expected goal of development cannot be achieved without sustainable development.
Sustainable development helps to solve the environmental problems which are seen
at the global level at present. In this regard, sustainable development has a great
importance. Some of the importances of sustainable development are explained
below:

i. Proper use of resources iv. Focus on people’s participation

ii. Realization of responsibility v. Long-term vision

iii. Development of basic areas vi. Determination of the limit of development

Objectives of sustainable development

a. Conservation of ecosystem

The principle of sustainable development is to create balance between biotic
and abiotic aspect of environment. It helps to protect earth. In order to conserve it,
the aquatic and terrestrial ecosystem should be protected.

b. Conservation of biodiversity

It is essential to protect the plants and animals of the earth. If these are affected
while carrying development works, it brings adverse effect on environment. Thus,
sustainable development focuses for the conservation of biodiversity. For this,
national and international programmes are to be conducted.

232 Blooming Science & Environment Book 6

c. Control of rapid population growth

People survive by consuming the means and resources on the earth. But rapid
population growth increases the consumption of resources rapidly. The resources
of this earth cannot be expanded to the need of people. Therefore, sustainable
development focuses to control population to minimize the consumption of resources
so as to conserve them.

d. Development of human resource

Human has an important role in utilization and conservation of environment. For the
sustainable use of resources, knowledge and skill of people should be developed.
The development of human resources helps to apply the principles of sustainable
development.

e. Increase in people’s participation

Local people are the consumers and conserve of resources. In the absence of people’s
participation, natural resources can’t be conserved. In this regard, sustainable
development emphasizes to increase people’s participation.

f. Conservation of cultural heritage

Man-made social tradition, customs, religious place and culture are focused aspect
of sustainable development. These important gifts of society are to be preserved
reforming the bad customs. Conservation of these aspects supports the sustainable
development.

g. Limit of carrying capacity

Human beings should conduct the development works considering the carrying
capacity of the earth. The earth has limited carrying capacity. Over use of resources
and unlimited development activities bring adverse effects on environment. Therefore,
man should conduct development activities in accordance with the carrying capacity
of the earth.

Population, environment and development activities

Population, environment and development activities are complementary to each
other. Environment is a very huge and complicated field in which people also live
in. Therefore, human should maintain the inter-relationship between population,
development and environment in a balanced way considering the development of
present and future generations. It is possible to maintain environmental balance if
human beings operate development and industrial activities with rational use of
authority they have.

Blooming Science & Environment Book 6 233

Environment

Agriculture Industry Health Security Shelter

Environment Communication Population and development Education Environment

Technology Human resources Employment Culture

Environment

Activity

Observe any of the development work like construction of road, bridge,community
building, industry / factory, hydroelectricity project, etc. whatever going on nearby
your house or school. Make a list of resources used and negative impacts on
environment.

Interrelationship between population, environment and development

People obtain all the resources necessary for them from the environment. Because
of this there is optimum utilization of natural resources. People should not forget the
responsibility towards environment protection while operating development activities.
It is essential that human should maintain understanding between their existence,
environment and development while formulating the patterns of development. The
following figure clearly shows the relationship between population, environment and
development:

Environment

Natural, Humanmade,
Economic, social and

cultural

Development Activities

Population Development

234 Blooming Science & Environment Book 6

The interrelationship between population, environment and development can be
studied as follows:

a) Use of natural resources

We should understand the importance of inter-relationship between various aspects of
environment. They should use natural resources in various ways. They build shelter
on the land and also produce the food they need cultivating in the land. They obtain
wood, firewood, herbs etc. from forest. They also receive air and water from the
environment. Human needs would have been fulfilled only if the inter-relationship
among the various aspects of environment remained strong and maintained.

The use of natural resources increases due to population growth. The use of land,
water etc. increases to grow food subsistence. Similarly, population growth causes
the growth of poverty, hunger, diseases, illiteracy, etc. If the growth of population
goes on, the needs of human cannot be fulfilled from natural resources.

b) Development and construction works

Human beings carry out various kinds of development works to fulfill their needs.
Development activities should be operated continuously to fulfill the needs and desires of
growing population. The aspect of environment conservation cannot be abandoned while
operating developmental activities.

c) Economic development

The development activities like construction of road, increase in agricultural
production, production of industrial materials, export of manufactured goods,
etc. are necessary to be operated in the country for economic development. Such
development activities provide employment to people. Skill is developed in them.
The level of their work increases .It results the economic development of a person,
society and country. The life standard of people does not change without the
developmental activities.

d) Social cultural activities

There are social and cultural activities in society. People protect, renovate, construct
traditional rituals, religious places, temples etc.These activities are development works
related to social and cultural aspects. The protection, promotion and development of
such aspects support to raise the culture of people. The relationship between the
activities of development of various aspects of population and environment should
be continuously adjusted and managed. The development works should fulfill the
needs of present generation. Similarly, it is our duty to protect the environment which
is able to fulfill the needs of future generation.

Local level efforts for sustainable development

Sustainable development is a process in which exploitation of natural resources is
done to meet the need of present generation without compromising the ability of

Blooming Science & Environment Book 6 235

future generations to meet their needs. In other words, sustainable development
is bearable or durable development. Development work should be conducted
considering the carrying capacity of the earth. Over exploitation of natural resources
produces adverse effects on environment. The degradation of environment makes it
difficult for the survival of living beings including man. Our future generations will
suffer from lack of life supporting means and resources.

The concept of sustainable development is to be translated into practice at local,
regional and global level. Government and various NGOs and INGOs play an
important role to support sustainable development from local level. At local level,
following efforts can be made for sustainable development.
i) Random deforestation must not be done since forest resources is a great wealth

for community and nation.
ii) Over cultivation in the limited land should be avoided to conserve soil.
iii) Overuse of chemical fertilizers and insecticides should be stopped as it reduces

the fertility of the soil.
iv) Overgrazing must not be done since it leads to desertification of land.
v) The use of non-renewable resources like mineral matters, natural gases etc.

should be minimized.
vi) Water sources should be kept clean and well maintained to prevent from drying.
vii) Cultural heritages like temples, monasteries, gumbas etc. should be preserved for

future generations as they are invaluable gift of our forefather.
viii) Flora and fauna should be protected since they are sources of income and also

they help for ecological balance.
ix) Afforestation should be done in the barren land, slope hills, road sides and

industrial areas.
x) Public participation must be enhanced in the conservation and promotion of

natural resources.

Main Points to Remember

1. Sustainable development encourages to have economic advantage by the
rational use of resources.

2. Sustainable development is essential for environmental conservation.

3. Sustainable development is also called retaining development.

4. Population, environment and development activities are complementary to each
other.

5. There is interrelation between population, environment and development.

236 Blooming Science & Environment Book 6

PRO J ECTWORK

Inquire with your parents, sister, brother and people of various organizations about
the development activities in your place. Write the name of development activities.
Select any one development activities among them. Then write about it briefly based
on the following points: a. Introduction b. Objective c. Program d. Advantages
e. Disadvantages and f. Conclusion.

Exercises

1. Answer these questions

a. What is sustainable development?
b. Write the importance of sustainable development.
c. Show the relation between population, environment and development.
d. Prepare a list of principles of sustainable development.
e. Write any 4 applications of sustainable development.
f. Write the differences between development and sustainable development.
g. Public awareness on sustainable development will support in

environmental protection, explain.
2. Fill in the blanks

a. .......................... is also called “retaining development.”
b. ..................... are .....................used to fulfill needs of population.
c. People obtain all necessary resources for them from .......................
d. Population, environment and development are .......................... to each

other.
3. Write true or false

a. Development works are related to environment.
b. Sustainable development is also called retaining development.
c. Increasing population plays important role for environment protection.
d. Population, environment and development are interrelated to each other.

Blooming Science & Environment Book 6 237

4. Match the following

development growth
natural conservation
population activities
environment sustainable
economic resources
5. Write short notes on

a. Sustainable development

b. Inter-relation betweeen population, environment and development.

6. Make a list of organizations and their work in your community for
sustainable development.

Glossary

retaining : keep something in position
barren land : empty area

renovate : repair

abandoned : vacant

subsistence : survival

biodiversity : range of organisms in an environment

beyond : away from

exploitation : unfair treatment

excessively : beyond the limit

sustainable : able to maintain

238 Blooming Science & Environment Book 6

A sample of work sheet for practical class

AIM: TO OBSERVE THE EFFECTS OF FORCE.
Materials Required:
TT ball, clay and syringe

TT ball Syringe

Theory:

List the effects of force.

_____________________________________________________________

_____________________________________________________________

_____________________________________________________________

_____________________________________________________________

_____________________________________________________________

_____________________________________________________________

_____________________________________________________________

_____________________________________________________________



Method:

1. Keep a TT ball on a table, blow it and observe.

2. Roll the same TT ball on the table and ask your friend to stop it.

3. Roll the same TT ball on the table and blow it to the direction of its motion and
observe its motion.

4. Take a syringe, pull its piston to the ball and press the piston closing its nozzle and
observe it.

5. Take some clay. Roll it into ball, put it on the table and press it and then observe.

6. Roll the TT ball on the table, blow it from the side and observe it.

Blooming Science & Environment Book 6 239

Observation: Observation (what Result
you saw)
S.N. Activity (what you
did)

1.
2.
3.
4.
5.
6.

Conclusion:
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________

Questions:

1. What is force?
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________

_____________________________________________________________

2. How can you increase the speed of your moving bicycle?

_____________________________________________________________
_____________________________________________________________
_____________________________________________________________

_____________________________________________________________

3. What is pushing force?

_____________________________________________________________
_____________________________________________________________
_____________________________________________________________
_____________________________________________________________

240 Blooming Science & Environment Book 6

MODEL QUESTIONS

Class: 6 Full Marks: 75

Subject: Science Time: 2 hours 15 min

Attempt all the questions.

Group: A (Physics)

1. a. Define measurement. Convert 500 meters to kilometers. (1+1)

b. Enlist any three effects of force. Give an example each of: random motion,
oscillatory motion and linear motion. (1.5+1.5)

2. a. A pair of scissors is an example of both lever and wedge. Explain. (2)

b. Define fossil fuel and biofuel with an example of each. (1.5+1.5)

3. a. What is longitudinal wave? Sketch a diagram in the support of your answer.
(1+1)

b. How a shadow is formed? What is meant by umbra and penumbra? (1+1+1)

4. a. Prove by an experiment that like poles repel and unlike poles attract. (2)

b. Write any two differences between magnetic and non-magnetic substances.
Define magnetic field. (2+1)

5. a. Sketch a diagram for a closed
circuit. Name a non-metal which is
a good conductor of electricity.
(1.5+0.5)

b. Answer the following questions
on the basis of diagram:

i. What is shown in the
diagram? (0.5)

ii. Is it easy to use? Why? (0.5+1)

iii. How is it different from a photo cell? (1)

Group B (Chemistry)

6. a. What is a compound? Is iron an element? Why? (1+0.5+0.5)

b. What is meant by filtrate? Write the suitable methods of separation for

Blooming Science & Environment Book 6 241

following mixtures:

i. Sand and iron fillings iii. Salt and sand

ii. Sand and gravel iv. Mud and water (1+0.5x4)

7. a. Why lime water turns milky when air is blown in it? (2)

b. Write any two points of difference between metals and non-metals.
Mention those two properties of metals due to which it can be used to
make cooking utensils. (2+0.5 2)

8. a. Definemalleability. Write any two uses of metals. (1+1)

b. Write any three uses of turmeric. Name the enzyme found in yeast.Write
chemical name of baking soda and table salt. (1.5+0.5+1)

Group C (Biology)

9. a. Write the name of phylum and a character of following invertebrates: (1+1)

i. Flea ii. Sea cucumber

b. Define dicotyledon. Enlist any two examples each of:(1+1+1)

i. Perennial plants ii. Fossorial animals

10. a. Sketch a diagram of leaf and label any two parts of it. (1+1)

b. Enlist any two conditions required for germination of seeds. Write two
functions of fruits. (2+1)

11. a. Why is mitochondria considered as power house of a cell. (2)

b. Draw the plant cell and label any four parts of it. (1+2)

12. a. Write the functions of xylem and phloem. (1+1)

b. Study the diagram and answer the following A
question. (a potted plant with a leaf covered B
with polythene)
C
i. Which life process is shown in figure?
Define the process. (0.5+1)

ii. What are A and B. (0.5+0.5)

iii. Which process is conducted by C? (0.5)

242 Blooming Science & Environment Book 6

Group D (Astronomy and Geology)

13. a. Write any two purposes of launching artificial satellites. (1+1)

b. Differentiate weather and climate with any two points. What is meant

by meteorites? (2+1)

Group E (Environment)

14. a. Define natural resources. Give any two examples of abiotic factors.
(1+1)

b. Give reasons:

i. Minerals are useful.

ii. Flood and landslide can be minimized by human. (1.5+1.5)

15. a. What is meant by sustainable development? Enlist any two importance of
such development. (1+1)

b. What are protected areas? Write any two national parks and wildlife
reserves of Nepal. (1+1+1)

Blooming Science & Environment Book 6 243

List of Video Experiments

URL Chapters QR Code

csp.codes/c06e01 Measurement

csp.codes/c06e02 Measurement

csp.codes/c06e03 Force and Motion

csp.codes/c06e04 Force and Motion

csp.codes/c06e05 Force and Motion

244 Blooming Science & Environment Book 6

csp.codes/c06e06 Simple Machine

csp.codes/c06e07 Simple Machine

csp.codes/c06e08 Heat and Temperature

csp.codes/c06e09 Light

csp.codes/c06e10 Light

Blooming Science & Environment Book 6 245

csp.codes/c06e11 Sound

csp.codes/c06e12 Magnet

csp.codes/c06e13 Electricity

csp.codes/c06e14 Matter

csp.codes/c06e15 Mixture

246 Blooming Science & Environment Book 6

csp.codes/c06e16 Air

csp.codes/c06e17 Metals and Nonmetals

csp.codes/c06e18 Living Beings

csp.codes/c06e19 Living Beings

csp.codes/c06e20 Living Beings

Blooming Science & Environment Book 6 247

csp.codes/c06e21 Cell

csp.codes/c06e22 Life Process

csp.codes/c06e23 Life Process

csp.codes/c06e24 Solar System

248 Blooming Science & Environment Book 6