Introduction to Environmental Science – uses, over-exploitation, conservation of water, Mineral Resources and case studies

1. Environmental Science – Water and
Mineral Resources
Presented by
V.N.Kowshalya
Assistant Professor
Department of Chemistry
Kongu Engineering College
Perundurai, Erode

2. UNIT - I - Environmental Studies and Natural Resources
Introduction to Environmental Science – uses, over-exploitation and
conservation of forest, water, mineral, food, energy and land
Resources – case studies

3. Introduction to Environmental Science
Environment:
The term environment is derived from a French word
‘environner’ which means ‘surrounding’. It refers to
an aggregate of all conditions that affect the existence,
growth, and welfare of an organism or a group of
organisms.
Definition: It can be defined as a sum total of all the living (biotic) and non-living
(Abiotic) elements and their effects that influence human life.
While all living or biotic elements are animals, plants, forests, fisheries, and birds, non-
living or abiotic elements include water, land, sunlight, rocks, and air.

4. Environmental Science:
“The systematic & scientific study of our environment and our role in it. This branch
includes the knowledge of Pure Science & to some extent Social Sciences”.
Environmental Studies:
“The branch of Study concerned with environmental issues. It has a broader coverage
than environmental science and includes the social aspects of the environment”.
Environmental Education:
Environmental education is a process that allows individuals to explore environmental
issues, engage them in problem solving, and take action to improve the environment.
As a result, individuals develop a deeper understanding of environmental issues and
have the skills to make knowledgeable and responsible decisions.

6. Objectives of Environmental Education
Awareness: To help individuals and social groups to acquire basic awareness of and
sensitivity towards the environment & its related problem.
Knowledge: To help individuals and social groups to acquire basic understanding of
the environment, its associated problems and their responsible role towards the
betterment of the environment.
Attitude: To help individuals and social groups to acquire social values, strong feeling
of concern for the environment and the motivation for actively participating in its
protection and improvement.
Skills: To help individuals and social groups to acquire the skills for solving
environmental problems.

7. Evaluation ability: To help individuals and social groups to evaluate environmental
measures and education program in terms of ecological, political, economical, social,
aesthetic and education factors.
Participation: To help individuals and social groups to develop a sense of
responsibility and urgency regarding environmental problems to ensure appropriate
action to solve those problems.

9. Importance of Environmental Studies
 Environmental Studies is useful in checking environmental pollution and related
solutions.
 It helps in maintaining ecological balance.
 It helps to gain skills to assess the environmental impact of human activities.
Environmental study will help to protect biodiversity.
 It gives us basic knowledge of environment and associated problems.
 It helps to achieve sustainable development .
 It helps to educate people regarding their duties towards the protection of
environment.
 The knowledge of environmental science will be applied to the study of agriculture..

10. International Efforts for Environment
 Environmental issues received international attention
about 35 years back in Stockholm Conference, held on
5th June, 1972.
 Since then we celebrate World Environment Day on
5th June.
 At the United Nations Conference on Environment
and Development held at Rio de Jeneiro, in 1992,
known popularly as Earth Summit.
 Ten years later, the World Summit on Sustainable
Development, held at Johannesberg in 2002,
highlighted the key issues of global environmental
concern.
 Later, Conference on Climate Change was held at
Copen Hagen in the year 2009 and is known as Copen
Hagen Summit.

11. Need for Public Awareness
 Earth’s resources are dwindling and our environment is being increasingly degraded
by human activities and hence something needs to be done.
 Government alone cannot perform all the clean-up functions.
 Individual/group efforts in their own every possible way has to be made to protect
our environment.
 Mass public awareness: newspapers, radio, television strongly influences public
opinion on conserving our environment.
Methods for Public Awareness
 Environmental education
 Through mass & media
 Through organizing seminars & conferences
 Entertainment
 Science centers
 Involvement of youth
 Through print, broadcast and internet

13. 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.
(Or)
Natural resources are resources that exist without any actions of human kind.
(Or)
Any stock or reserve that can be drawn from nature is a natural resource.
Examples:
water, air, soil, minerals, coal, forests, crops and wildlife
Classification of Natural Resources:
The natural resources are of two kinds
1. Renewable Resources
2. Non-Renewable Resources

14. 1. Renewable Resources
The resources which cannot be exhausted even after continuous utilization are termed
as renewable resources.
Examples: Sun, Wind, and Tidal energy etc.
2. Non-Renewable Resources
The resources which cannot be immediately replaced once they are depleted are called
Non-renewable resources.
Examples: Fossil fuels, such as coal, petroleum and natural gas etc.

15. Here we are going to discuss the following six Natural Resources

16. 2.Water resources
Introduction
Water is, literally the source of life on earth.

17. Water is an Unique Resource
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◦C to 100◦C.
It has the highest specific heat, due to which it warms up
and cools down very slowly without causing shocks of
temperature jerks to the aquatic life.
 It has a high latent heat of vaporization.
 It is an excellent solvent for several nutrients.
It has an anomalous expansion behaviour.
Due to high surface tension and cohesion it can easily rise
through great heights.

18. Water use and Overutilization
Due to its unique properties water is of multiple uses for all living organisms.
Water is absolutely essential for life. Water is used for drinking, irrigation, transportation, washing
and waste disposal for industries and used as a coolant for thermal power plants.
Water shapes the Earth’s surface and regulates our climate.
More than 99% of Earth’s water in its natural state is unavailable or unsuitable for beneficial
human use.
Thus, the amount of freshwater for which all the people, animals and plants on Earth compete is
even less than 1% of the total.
With increasing population pressure and rapid development, the demands for water have increased
tremendously. On a global average 70 % of water is used for agriculture and 25 % of water is used
in industrial sector.

19. 2. Ground water sources:
After glaciers, ice caps and snowfields, ground water is the next largest fresh water reservoir.
Till some time back ground water was considered to be very pure. However, of late, even
groundwater aquifers have been found to be contaminated.
A layer of sediment or rock that is highly permeable and contains water is called an aquifer.
Aquifers may be of two types :
Unconfined aquifers which are overlaid by permeable earth materials and they are recharged by water
seeping down from above in the form of rainfall and snow melt.
Confined aquifers which are sandwiched between two impermeable layers of rock or sediments and are
recharged only in those areas where the aquifer intersects the land surface.
SOURCES OF FRESH WATER:
1. Surface water sources:
i. Natural Lakes and Ponds
ii. Artificial Impounding Reservoirs
iii. Rivers and Streams
iv. Sea water

20. Threats to fresh water resources
Climate change causes change in frequencies of droughts and floods.
Depletion of aquifers caused by over-consumption as a result of population growth.
Pollution and contamination by sewage, agricultural and industrial runoff.

21. At the same time…….
Water was being wasted in water parks,
theme parks and swimming pools etc.,

22. Effects of Groundwater usage
i.Subsidence :
When groundwater withdrawal is more than its recharge rate, the sediments in the aquifer get
compacted, a phenomenon known as ground subsidence. Huge economic losses may occur due to
this phenomenon because it results in the sinking of overlying land surface. The common problems
associated with it include structural damage in buildings, fracture in pipes, reversing the flow of
sewers and canals and tidal flooding.
ii.Water logging:
When excessive irrigation is done with brackish water it raises the water table gradually leading to
water-logging and salinity problems.
iii. Lowering of water table:
Mining of groundwater is done extensively in arid and semi-arid regions for irrigating crop fields.
However, it is not advisable to do excessive mining as it would cause a sharp decline in future
agricultural production, due to lowering of water table.
iv. Water pollution :
Discharge and dumping of wastes very often seeps down into groundwater causing pollution
problems.

23. Floods
Heavy rainfall often causes floods in the low-lying coastal areas. Prolonged downpour can also
cause the over-flowing of lakes and rivers resulting into floods.
Deforestation, overgrazing, mining, rapid industrialization, global warming etc have contributed
largely to a sharp rise in the incidence of floods, which otherwise is a natural disaster.
Droughts
When annual rainfall is below normal and less than evaporation, drought conditions are created.
Drought is a meteorological phenomenon, but due to several anthropogenic causes like over grazing,
deforestation, mining etc. there is spreading of the deserts tending to convert more areas to drought
affected areas.

26. Big Dams benefits and problems
Big dams are often regarded as a symbol of national development.

28. Case Study 1
Cherrapunji was famous because it received the largest volume of rainfall in the world.
It still does but ironically, experiences acute water shortages. This is mainly the result
of extensive deforestation (no trees to hold the water and the water run off to rivers.
Because proper methods of conserving rainwater are not used. There has been
extensive soil erosion. Only rain water harvesting can sort out the problems of the
world's wettest town. Scientists point out the example of Jaisalmer, one of the driest
towns in India in Rajasthan, with rainfall levels as little as 100 mm of water per year,
where it was found that if you harvest water on just one hectare of land, you have
captured as much as one million litres of water --enough to meet drinking and cooking
water needs of 182 people at 15 litres per day for one year.

29. Case Study 2
Sardar Sarovar Dam
 The Sardar Sarovar Dam is a gravity dam on the
Narmada river near Navagam, Gujarat in India.
 It is one of the largest water resources projects of
India covering four major states - Maharashtra,
Madhya Pradesh, Gujarat and Rajasthan.
 The project took form in 1979 as part of a
development scheme to increase irrigation and
produce hydroelectricity.
 Most importantly, This dam is one of India's most
controversial project and its environmental impacts
are widely debated.
 It is, in fact, designed as a concrete gravity dam,
having a height up to FRL 138.68 m.

30. Projected Benefits : Recreation 38% Flood control 18% Fire & farm ponds 17%
Irrigation 11% Tailing & others 8% Undetermined 4% Hydroelectric 3% Debris control
1% Recreation Flood control Fire & farm ponds Irrigation Tailing & others
Undetermined Hydroelectric Debris control

31. Environmental impacts of Sardar Sarovar dam project
1) Submergence causing loss of forest and agricultural land :
In order to minimize the adverse effects of submergence it becomes necessary
 To compensate and mitigate the losses due to deforestation.
 To reduce the dam height up to a minimum possible value.
After thoroughly examining, dam height was finally decided FRL 138.68 m by
constituted tribunal in 1979.
2) Loss of wild life :
 It was clarified that it will not cause any loss of flora and fauna.
 Also it will help to develop five sanctuaries.
3) Displacement of Tribals :
 Tribals, living in submergence zone, need to be displaced elsewhere.
 Nearly 2000-3000 families may opt rehabilitation in Gujarat, which is
manageable.

32. 4) Submergence of old monuments:
• No protected archaeological monument lies in submergence area.
• Only few temples, like Shoolpaneshwar Mahadev at village Supan, are
likely to be affected.
5) Water-logging and Salinity problem:
• The problem of waterlogging and soil salinity is little serious here.
• It is so because the command areas of the projects have largely black
soils, which have very good water retention capacity.
6) Seismic effect of the reservoir :
• By survey, it was concluded that formation of reservoir in this area
may cause earthquake to occur but not of destructing dimensions.
• So the dams have been designed to withstand earthquake shocks of
magnitude 6.5 (Richter scale).
7) Health aspects :
• No risk of malaria & Schistosomiasis like diseases by irrigation
facilities for 17 years (As studied by teams of WHO)

33. 3. Mineral Resources

34. Minerals are naturally occurring, inorganic, crystalline solids having a definite chemical composition and
characteristic physical properties.
Distribution of mineral resources in India:
Coal and Lignite : West Bengal, Jharkhand, Orissa, MP, AP
Uranium : Jharkhand, AP, Meghalaya, Rajasthan
Aluminium : Jharkhand, West Bengal, Maharashtra, MP, Tamil Nadu
Iron : Jharkhand, Orissa, Madhya Pradesh, Andhra Pradesh, Tamil Nadu, Karnataka, Maharashtra and Goa
Copper : Rajasthan, Bihar, Jharkhand, Karnataka, Madhya Pradesh, West Bengal, Andhra Pradesh
and Uttarakhand

35. Classification of Minerals:
Based on the properties, minerals are basically of two types :
i. Non-metallic minerals - Graphite, diamond, quartz, feldspar
ii. Metallic minerals - bauxite, laterite, haematite
Based on the usage, minerals are classifies into two types :
i. Critical minerals are essential for the economy of a nation – iron, aluminium, copper, gold
ii. Strategic minerals are those required for the defense of a country – Manganese, cobalt, platinum,
chromium

36. Uses and Exploitation of mineral resources:
 Development of industrial plants and machinery
Generation of energy(Ex- coal, uranium)
Construction
Defense equipments
Transportation
Communication- wires, cables, electronic devices
Medicinal system- particularly in Ayurvedic-
Ex- Sulphur pyrites
 Agriculture- as fertilizers, seed dressings and
fungicides. Ex- zineb (contain Zn)
maneb (contain Mn )
Jewellery for example, gold, diamond

38. Environmental impacts of mineral extraction
Mining:
Mining is done to extract minerals from deep deposits in soil.
Types of mining :
i.Surface mining
Surface mines are mining operations to extract deposits of mineral resources that are close to the
surface.
a. Open-pit mining in which machines dig holes and remove the ores. Ex- Copper, iron, gravel, limestone,
marble.
b. Dredging in which chained buckets and draglines are used which scrap up the minerals from under-water
mineral deposits.
c.Strip mining in which the ore is stripped off by using bulldozers, power shovels and stripping wheels.
Ex- phosphate rocks
ii.Sub-surface mining
Sub-surface mining is used for the extraction valuable minerals from the earth.

39. The environmental damage caused by mining activities are as follows:
i.Devegetation and defacing of landscape-The topsoil as well as the vegetation are removed
from the mining area to get access to the deposit.
ii. Land subsidence- This is mainly associated with underground mining.
iii. Groundwater contamination – Mining disturbs the natural hydrological processes
and also pollutes the groundwater
iv.Surface water pollution – The acid mine drainage often contaminates the nearby streams
and lakes.
v.Air pollution- Smelting leads to the emission of soot, arsenic, cadmium and lead to the
atmosphere.
vi.Occupational health hazards- due to constant exposure miners working in different types
of mines suffer from asbestosis, silicosis, black lung disease etc.

41. Remedial measures:
Adopt eco-friendly mining technology
Use microbial leaching technique. The bacterium Thiobacillus ferroxidans has been successfully and
economically used for extracting gold embedded in iron sulphide ore.
 Restoration of mined areas by re-vegetating them with appropriate plant species.
Prevention of toxic drainage discharge and conforming to the standards of air emissions are essential
for minimizing environmental impacts of mining.

42. Case study