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Multidisciplinary nature of
environmental studies

UIPS Panjab University, Chandigarh.

M.Pharma ( 2nd sem )

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ENVIRONMENT

 ‘ENVIRONMENT’ is derived from the French word ENVIRONNER, which means
to encircle or surround.

 All the biological and non –biological entities surrounding us are included in
environment .

 As per Environment (protection) Act, 1986, environment includes all the
physical and biological surroundings of an organism along with their
interactions .

 ENVIRONMENT is thus defined as “the sum total of water ,air and land and
the inter-relationships that exist among them and with the human beings ,
other living organism and material.”

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CONTD.

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IMPORTANCE OF ENVIRONMENT

 ENVIRONMENT belongs to all and is important to all.

 Whatever be the occupation or age of a person , he will be affected by
environment and also he will affect the environment by his deeds.

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Natural resources

 Life on this planet earth depends upon a variety of goods and services
provided by the nature ,which are known as Natural resources.

 Examples:- water ,soil, minerals, coal, forests, crops and wildlife.

 The natural resources are of two kinds:-

Non-
Renewable

renewable
resources

resources

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Contd.

 RENEWABLE RESOURCES:- which are inexhaustive and can
be regenerated within a given span of time . E.g. forests ,
wildlife, wind energy , biomass energy etc.

 Solar energy is also a renewable form of energy as it is an
in exhaustive sources of energy.

 NON-RENEWABLE RESOURCES:-which cannot be
regenerated e.g. fossil fuels like coal , petroleum ,
minerals etc. once we exhaust these reserves ,the same
cannot be replenished.

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Natural resources

 The major natural resources are :-

 1. Forest resources

 2. Water resources

 3. Mineral resources

 4. Energy resources

 5. Land resources

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FOREST RESOURCES

 Forests are one of the most important natural resources on this earth.
Covering the earth like a green blanket these forests not only produce
innumerable material goods, but also provide several environmental services
which are essential for life.

 About 1/3rd of the world’s land area is forested which includes closed as well
as open forests.

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Uses of forests:

 Commercial uses: forests provide us large number of goods which include
timber, firewood, pulpwood , food items , gum resins , the total worth of
which is estimated to be more than $3oo billion per year.

 Ecological uses:

❖ Production of oxygen

❖ Reduction of global warming

❖ Wildlife habitat

❖ Soil conservation

❖ Pollution moderators

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Deforestation:

 The total forest area of the world in 1900 was estimated to be 7,000 million
hectares which was reduced to 2890 million ha in 1975 and fell down to just
2,300 million ha by 2000.

 Deforestation rate is relatively less in temperate countries, but it is very
alarming in tropical countries where it is as high as 40-50 percent and at the
present rate it is estimated that in the next 60 years we would lose more than
90 percent of our tropical forests.

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Major Causes of Deforestation:

 Shifting cultivation

 Overgrazing

 Fuel requirements

 Development projects

 Growing food needs

 Raw materials for food industry

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CASE STUDIES:

 Desertification in hilly regions of the Himalayas:

Deforestation in Himalayas, involving clearance of natural forests and
plantation of monocultures like Pinus roxburghi, Eucalyptus camadulensis etc.
have upset the ecosystem by changing various soil (edaphic) and biological
properties. Nutrient cycling has become poor, original rich germplasm is lost and
the area is invaded by exotic weeds. These areas are not able to recover and
are losing their fertility. The entire west Khasi hill district of Meghalaya in
North-east Himalayas, Ladakh and parts of Kumaon and Garhwal are now facing
the serious problem of desertification.

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Major Activities in Forests :

 Timber Extraction: Logging for valuable timber, such as teak and Mahogany
not only involves a few large trees per hectare but about a dozen more trees
since they are strongly interlocked with each other by vines etc.

 Mining: Mining operations for extracting minerals and fossil fuels like coal
often involves vast forest areas.

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DAMS AND THEIR EFFECTS ON FORESTS AND
PEOPLE:

 Big dams and river valley projects have multi-purpose uses and have been
referred to as “Temples of modern India”.

 However, these dams are also responsible for the destruction of vast areas of
forests. India has more than 1550 large dams, the maximum being in the state
of Maharashtra (more then 600), followed by Gujarat (more then 250) and
Madhya Pradesh (130).

 The highest one is Tehri dam, on river Bhagirathi in Uttaranchal and the
largest in terms of capacity is Bhakra dam on river Satluj in H.P. Big dams
have been in sharp focus of various environmental groups all over the world
which is mainly because of several ecological problems including
deforestation and socio-economic problems related to tribal or native people
associated with them.

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WATER RESOURCES

 Water is an indispensable natural resource on this earth on which all life
depends. About 97% of the earth’s surface is covered by water and most of the
animals and plants have 60-65% water in their body.

 Water is characterized by certain unique features which make it a marvelous
resource:

❖ It exists as a liquid over a wide range of temperature i.e. from 0° to100°C.

❖ It has the highest specific heat

❖ It has a high latent heat of vaporization

❖ It is an excellent solvent for several nutrients.

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WATER USE AND OVER-EXPLOITATION:

 Due to its unique properties water is of multiple uses for all living organisms.

 Human beings depend on water for almost every developmental activity.

 Water is used for drinking, irrigation, transportation, washing and waste
disposal for industries and used as a coolant for thermal power plants

 Water use by humans is of two types:

❖ water withdrawal: taking water from groundwater or surface water resource
and

❖ water consumption: the water which is taken up but not returned for reuse.

 With increasing human population and rapid development, the world water
withdrawal demands have increased many folds and a large proportion of the
water withdrawn is polluted due to anthropogenic activities.

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Water: A Precious Natural Resource

 Although water is very abundant on this earth, yet it is very precious.

 Out of the total water reserves of the world, about 97% is salty water(marine)
and only 3% is fresh water.

 Even this small fraction of fresh water is not available to us as most of it is
locked up in polar ice caps and just 0.003% is readily available to us in the
form of groundwater and surface water.

 Overuse of groundwater for drinking, irrigation and domestic purposes has
resulted in rapid depletion of groundwater in various regions leading to
lowering of water table and drying of wells.

 Pollution of many of the groundwater aquifers has made many of these wells
unfit for consumption.

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CONFLICTS OVER WATER:

 The Indus Water Treaty:

❖ The Indus, one of the mightiest rivers is dying a slow death due to dams and
barrages that have been built higher up on the river.

❖ In 1960, the Indus water treaty was established vide which Indus, the Jhelum and
the Chenab were allocated to Pakistan and the Satluj, the Ravi and the Beas were
allocated to India.

❖ Being the riparian state, India has pre-emptive right to construct barrages across
all these rivers in Indian territory.

❖ However, the treaty requires that the three rivers allocated to Pakistan may be
used for non-consumptive purposes by India i.e. without changing its flow and
quality.

❖ with improving political relations between the two countries it is desirable to work
out techno-economic details and go for an integrated development of the river
basin in a sustainable manner

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CONFLICTS OVER WATER:

 The Satluj-Yamuna link (SYL) canal dispute: The issue of sharing the Ravi-Beas
waters and SYL issue between Punjab and Haryana is being discussed time and
again and the case is in the Supreme Court.

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MINERAL RESOURCES

 Minerals are naturally occurring, inorganic, crystalline solids having a definite
chemical composition and characteristic physical properties.

 There are thousands of minerals occurring in different parts of the world.

 However, most of the rocks, we see everyday are just composed of a few
common minerals like quartz, feldspar, biotite, dolomite, calcite, laterite
etc.

 These minerals, in turn, are composed of some elements like silicon, oxygen,
iron, magnesium, calcium, aluminium etc

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USES AND EXPLOITATION:

 Minerals find use in a large number of ways in everyday use in domestic, agricultural,
industrial and commercial sectors and thus form a very important part of any nation’s
economy.

 The main uses of minerals are as follows:

❖ Development of industrial plants and machinery.

❖ Generation of energy e.g. coal, lignite, uranium.

❖ Transportation means.

❖ Communication- telephone wires, cables, electronic devices.

❖ Medicinal system- particularly in Ayurvedic System.

❖ Formation of alloys for various purposes (e.g. phosphorite).

❖ Agriculture–as fertilizers, seed dressings and fungicides (e.g. zineb containing zinc, Maneb-
containing manganese etc.).

❖ Jewellery e– .g. Gold, silver, platinum, diamond

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Major reserves and important uses of some of
the major metals:

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Major uses of some non-metallic
minerals:

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ENVIRONMENTAL IMPACTS OF MINERAL
EXTRACTION AND USE:

 India is the producer of 84 minerals the annual value of which is about Rs.
50,000 crore. major mines need a mention here which are known for causing
severe problems:

 Jaduguda Uranium Mine, Jharkhand- —exposing local people to radioactive
hazards.

 Jharia coal mines, Jharkhand-—underground fire leading to land subsidence and
forced displacement of people.

 Sukinda chromite mines, Orissa-—seeping of hexavalent chromium into river
posing serious health hazard, Cr6+ being highly toxic and carcinogenic.

 Kudremukh iron ore mine, Karnataka-—causing river pollution and threat to
biodiversity.

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CASE STUDIES:

 Mining and quarrying in Udaipur-

❖ About 200 open cast mining and quarrying centers in Udaipur, about half of which
are illegal are involved in stone mining including soapstone, building stone, rock
phosphate and dolomite.

❖ The mines spread over 15,000 hectares in Udaipur have caused many adverse
impacts on environment.

❖ About 150 tonnes of explosives are used per month in blasting.

❖ The overburden, wash off, discharge of mine water etc. pollute the water

❖ The hills around the mines are devoid of any vegetation except a few scattered
patches and the hills are suffering from acute soil erosion.

❖ The blasting activity has adversely affected the fauna and the animals like tiger,
lion, deer and even hare, fox, wild cats and birds have disappeared from the
mining area

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Energy Resources

 Energy consumption of a nation is usually considered as an index of its
development.

 because, almost all the developmental activities are directly or indirectly
dependent upon energy.

 The first form of energy technology probably was the fire,
which produced heat and the early man used it for cooking and heating
purposes.

 Wind and hydropower are also in use since thousands of years.

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Renewable and non renewable energy
sources.

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Renewable energy sources

1. Solar energy

2. Wind energy

3. Hydropower

4. Tidal energy

5. Ocean thermal energy

6. Biogas etc.

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Solar energy

 Sun is the ultimate source of energy, directly or indirectly for all other forms
of energy.

 The nuclear fusion reactions ocurring at the surface of the sun releases
enourmous quantity of energy in the form of heat and light.

 From long ago we have been using the solar energy for,

i. Drying clothes

ii. Drying food and grains

iii. Obtaining salt from sea water.

but, now a days the modern science has developed many other devices,

which helps in harvesting the solar energy.

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 Some important solar energy harvesting devices are,

1) Solar heat collecter :- passive solar heat collecter are the materials which
absorbe heat during day time and release it during night.

2) Solar cells :- also known as photovoltaic cells. Made up of a semiconductor
material like gallium or silicon. Solar cells are widely used in calculators,
watches, radio etc.

3) Solar cooker :- make solar heat use by reflecting solar radiation by using the
mirror directly on glass sheet.which covers the black coloured container in
which food is kept.

4) Solar water heater :- uses natural sunlight to heat water. Water flows thrugh
the tubes absorbd heat and becomes hot.

5) Solar furnance :- Thousands of small mirrors are arranged in concave
reflectors which collect the solar heat and produce high tempreture.

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Wind energy

 The high speed winds have a tremondous energy in them as kinetic energy
due to motion present.

 The driving force of the wind is sun.

 Wind energy is harnessed by using wind mills, the blades of wind mills keep
rotaiting due to force of the wind.and then the rotaiting energy is converted
to mechanical energy.

 The mini mum speed required for the working of wind mills is 15 km/hr.

 at present we are generating about 1020 MW wind energy.

 The largest wind farm is near kanyakumari in Tamilnadu. Generating 380
MW electricity.

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Hydropower

 The water flowing in river is collected in dam and stosred and make it to fall
from the height.

 The blades of the turbine located at the bottom of the dam starts rotating
due the falling water which rotate the generator and produce electricity.

 The minimum height of the water fall to produce electricity should be 10
meters.

 Till now india is utilising just about 11% of its total hydropower generating
potential.

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Tidal energy

 Ocean tides produced by gravitational force of sun and moon have large
amount of energy.

 The high tide and low tide refers to the rise and fall in the water level.

 Which helps in the rotating of the turbines and production of the electricity
by rotating the generators.

 Only few cities in the world uses the tidal energy like,

1. Bay of fundy, canada

2. France

3. Gulf of kutch ,India

4. Sundar ban ,India

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Non-renewable energy sources

Some of the most commonly used non-renewable resources are,

1. Coal

2. Petroleum

3. Natural gas

4. Nuclear energy etc.

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Coal

 Coal is classified as a nonrenewable energy source because it takes millions of
years to form.

 the ancient plants get burried inside the earth, and then due to the heat and
pressure it convertes to the coal over million of years time.

 Coal is mainly of three types,

1. Anthracite [ hard coal ] 90% carbon

2. Bituminous [ soft coal ] 80% carbon

3. Lignite [ Brown coal ] 70%carbon

 India has 5% of the worlds coal.

 At present coal reserve is about to last for 200 years, if the use increase by 2%
per year then it will lasts for 65 years.

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Petroleum

 It is the lifeline of global economy.

 There are 13 countries in the world having 67% of the petroleum reserves,

 which together form the OPEC (Organization of Petroleum exporting
countries).

 About 1/4th of the oil reserves are in Saudi Arabia.

 At present rate of usage worlds crude oil reserviour will exhaust in 40 years.

 Crude oil is complex mixture of alkane hydrocarbon, so they needed to
purified by fractional distillation.

 During which diffrent constituent seprate out at diffrent tempreture’

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Natural gas

 It is mainly composed of methane (95%) with small amounts of propane and
ethane.

 It is a fossil fuel. it has been formed by decomposing remains of dead
animals and plants buried under the earth.

 Natural gas is the cleanest fossil fuel.

 Russia has maximum reserves 40%, Iran (14%) and USA (7%).

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Land resources

 Land is the most important valuable resource for mankind,

1. It provides food, fibre, medicine.

2. It is a mixture of inorganic materials and organic materials.

3. To construct building.

 Rate of renewal is faster than the rate of renewal therefore it is considered
as a non renewable resource.

 It takes nearly 200 to 1000 years for the formation of 1 inch of soil layer i.e
2.5 cm.

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Land degradation

 It is a process of deterioration of soil or loss of fertility.

 Effects of land degradation:

1. Soil texture and soil structure are destructed.

2. Loss of soil fertility.

3. Loss of valuable nutrients.

4. increase in water logging, salinity, alkalinity and acidity problem.

5. Loss of economic social and biodiversity.

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Soil erosion

 The process of removal of superficial layer of the soil from one place to
another is called soil erosion.

 Types of soil erosion

 1. Normal erosion:

It is caused by gradual removal of top soil by the natural process. The rate of
erosion is less.

 2. Accelerated erosion:

It is caused by man made activities. The erosion is much faster than the rate
formation of soil.

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Causes of soil erosion

 Following are the causes,

i. Water :-
water causes soil erosion in the form of rain, run off, rapid flow etc.

ii. Wind :-
It carry away the fine particles of soil creates soil erosion

iii. Land slide :- It causes soil erosion.

iv. Construction :-
Construction of dams, buildings, roads removes protective vegetal cover and
leads to soil erosion.

v. Deforestation :-

 35% of soil erosion is due to over grazing and 30% is due to deforestation.

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Soil conservation practices

1. Crop rotation :- Process of growing different crops in successive year on the
samew land. It prevents the loss of fertility of the soil.

2. Mulching :- Soil is covered with cropl residues and other form of plant litters.

3. Strip cropping :- Planting of crops in rows to check flow of water.

4. Wind break :- Trees are planted in long rows along the boundary of cultivated
lands, which block the wind and reduces soil erosion.

5. Alley cropping :- it is a type of intercropping in which the crops are planted
between rows of trees or shrubs.

6. Tree plantation

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REFERENCES:

 A.Kaushik and C.P.Kaushik ; Perspectives in environmental studies; New age
international publishers; second edition; page no. 1-53

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Thank
you….!

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