Environmental Science and Engineering-GE 2021

Unit-1Environment, Ecosystem and

Biodiversity.

Dr. V.Nagarajan

UNIT-I

Definition, scope and importance of Risk and hazards; Chemical hazards, Physical hazards,

Biological hazards in the environment – concept of an ecosystem – structure and function

of an ecosystem – producers, consumers and decomposers- Oxygen cycle and Nitrogen

cycle – energy flow in the ecosystem – ecological succession processes – Introduction,

types, characteristic features, structure and function of the (a) forest ecosystem (b)

grassland ecosystem (c) desert ecosystem (d) aquatic ecosystems (ponds, streams, lakes,

rivers, oceans, estuaries) – Introduction to biodiversity definition: genetic, species and

ecosystem diversity – biogeographical classification of India – value of biodiversity:

consumptive use, productive use, social, ethical, aesthetic and option values – Biodiversity

at global, national and local levels – India as a mega-diversity nation – hot-spots of

biodiversity – threats to biodiversity: habitat loss, poaching of wildlife, man-wildlife

conflicts – endangered and endemic species of India – conservation of biodiversity: In-situ

and ex-situ conservation of biodiversity. Field study of common plants, insects, birds Field

study of simple ecosystems – pond, river, hill slopes, etc.

UNIT-I

Definition, scope and importance of Risk and hazards; Chemical hazards, Physical hazards,

Biological hazards in the environment – concept of an ecosystem – structure and function

of an ecosystem – producers, consumers and decomposers- Oxygen cycle and Nitrogen

cycle – energy flow in the ecosystem – ecological succession processes – Introduction,

types, characteristic features, structure and function of the (a) forest ecosystem (b)

grassland ecosystem (c) desert ecosystem (d) aquatic ecosystems (ponds, streams, lakes,

rivers, oceans, estuaries) – Introduction to biodiversity definition: genetic, species and

ecosystem diversity – biogeographical classification of India – value of biodiversity:

consumptive use, productive use, social, ethical, aesthetic and option values – Biodiversity

at global, national and local levels – India as a mega-diversity nation – hot-spots of

biodiversity – threats to biodiversity: habitat loss, poaching of wildlife, man-wildlife

conflicts – endangered and endemic species of India – conservation of biodiversity: In-situ

and ex-situ conservation of biodiversity. Field study of common plants, insects, birds Field

study of simple ecosystems – pond, river, hill slopes, etc.

USA former President Herbert Hoover, who was an engineer before he became a politician, said:o The great liability of the engineer …compared to men of other professions……is

that his works are out in the open where all can see them. His acts …..step by step …are in hard substances.

o He cannot bury his mistakes in the grave like the DOCTORS. (Tuticorin incident)o He cannot argue them into thin air…..or blame the judge…..like the LAWYERS.o He cannot, like the ARCHITECT, cover his figures with trees and vines. (TN-

Assembly Building)o He cannot, like the politicians, screen his shortcomings by blaming his

opponents….and hope the people will forget. o The ENGINEER simply cannot deny he did it.

If his works do not work……he is damned.

• Civil Engineering is a Renaissance field that requires the knowledge of many disciplines.

Quotes

• A good scientist is a person with original ideas. A good engineer is a person who makes a design that works with as few original ideas as possible . Freeman Dyson

• The joy of engineering is to find a straight line on a double logarithmic diagram. Thomas Koenig

• One has to watch out for engineers – they begin with the sewing machine and end up with the atomic bomb. Marcel Pagnol

• Nothing can be of great worth or holy which is the work of builders and mechanics.

Zeno, Stoic Philosopher.

History of Engineering

Military Engineering (making catapults, towers, and other instruments used for war and building

fortifications for defense, making bridges, canals etc.,)

Engineering Non-Military Engineering (included all

engineers that did not practice military engineering).

• Civil Engineering - 18th century- the term came into use to describe engineering work that was performed by civilians for nonmilitary purposes.

• First “Civil Engineer” was an Englishman, John Smeaton in 1761.• Civil Engineers have saved more lives than all the doctors in history - development

of clean water and sanitation systems.• First college in the U.S that included Civil Engineering as a separate discipline was

Norwich University established in the year 1819.• ASCE is the first national engineering society in U.S and was founded in 1852.

(pioneer body for technical promotion of Civil Engineering)

EnvironmentDefinition, Scope and Importance of Environment- Need for Public awareness.

Environment - Environner – to encircle or surround.

• Literary environment means the surrounding external conditions influencing development or growth of people, animal or plants; living or working conditions etc.

• Douglas and Holland: ‘The term environment is used to describe, in the aggregate, all the external forces, influences and conditions, which affect the life, nature, behaviour and the growth, development and maturity of living organisms.

• Environment (Protection) Act,1986 - Environment is the sum total of water, air and land, inter-relationships among themselves and also with human beings, other living organisms and property.

EnvironmentDefinition, Scope and Importance of Environment- Need for Public awareness.

• Environment- A Multidisciplinary subject where different aspects are dealt with holistic approach. The study involves Life Science- to under stand biotic components and its interactions

Basic concepts of P,C, Geology,Atmospheric science,Geography and Oceanography- to understand the structure of abiotic components and energy transfer and flow

Maths, Statistics, CSE- tools in mathematical modeling and management.

Education, Economics,Sociology and Mass communication- provides input to socio-economic aspects for various developmental activities.

Synthesis of EE,CE, Hyd, ChE- provides technological solutions for treatment and disposal of wastes.

Laws- tool for regulation, enforcement and thereby protection of Environment.

As per UNESCO(1971), Objectives of ES are

Creating the awareness

Imparting basic knowledge

Developing an attitude

Motivating for public participation for protection

Acquiring skills

Striving to attain harmony with nature.

Objectives of Environmental Studies

Environmental science can be specifically applied in the following

spheres:

Ecosystem Structure and Function- study of biotic and abiotic

system.

Natural Resource Conservation (forests,water etc,.)

Environmental Pollution Control

Environmental management

Scope of environmental studies in industry.

Research and development

Social Development (NGO's -public awareness)

Scope of Environment.

Scope of The Environmental Studies:The scope of the environmental studies are summarised as:

-To study the interrelationship between biotic and abiotic

components.

-To carry out the impact analysis and environmental audit in

order to minimise the environmental problems.

-Reduce the pollution.

-Managing the unpredictable disaster.

-To create awareness to the public.

Risk and Hazard• Risk - in terms of a hazard, chance, bad

consequences, loss, etc., exposure to mischance. • Risk - in terms of to expose to chance of injury or

loss, venture on, accept the chance of.

Occupational and Environmental Epidemiology and in Environmental Engineering,

• Hazard is the potential to cause harm; • Risk on the other hand is the likelihood of harm

Physical Hazards

Need for Public awareness.o Due to many discoveries and inventions from 16th century

onwards, man has over exploited the natural resource which leads to many environmental problems such as o acid rain, oozone layer depletion, ogreen house effect, o land slides, o cancer and other health problems.

o Lack of awareness and less number of people participation leads to poor pollution management which are the major reasons for climate instability and unhealthy ecosystem.

o Hence, it is necessary to create awareness to the public about environmental problems and to protect the environment through implementing proper regulations.

o In order to protect the environment from the pollution, Supreme

court has initiated the environmental awareness to the public

through government and non governmental agencies.

o And it is important duty of us to cooperate with government from

our side and work for the protection of environment.

o The Active co-operation of every one, at every level of social

organizations, scientist- educationalists, social workers, politicians,

administrators and public is needed for issues concerning

environment. Individuals collectively make a society or a state.

o Movements, which begin at gram root levels, effects the ideologies

and policies of a country or the nation as a whole more effectively

than the policies introduced from top to downwards.

Forest Resources.o Forest is a highly complex natural resource.o It is a constantly changing environment made up of a living and

non living things.• Living matters- all kinds of plants majorly trees, wildlife and

microscopic soil organisms• Non living – water, nutrients, rocks, sunlight and air.

o Key benefits of Forests are:o Provides clean water.o Provides clean air.o Provides home to unique plants and animals.o Source of economic growtho Provides recreational facilities.o Ecological benefits.

o Deforestation ( loss of forest cover- land that is permanently converted into farm land, lakes, houses etc,.)

o FAO defines deforestation as change of forest with depletion of tree crown cover more than 90%.

o Less than 90% depletion of tree crown cover is considered as forest degradation. (Logging).

o Forest degradation rate is comparatively higher than deforestation.

Causes of Deforestationo Agriculture. (grazing cattle, planting crops etc,.)

• Central America – 40% of rainforests cleared for cattle pasture

o Commercial Logging.( Timber and wood pulp)

o The cash crop economy ( Malaysia- rubber and oil palm

plantations)

o Mining and Dams

• Brazil- The Grand Carajas Project- Mining-9,00,000 sq.km and

affected 23 tribal groups.

• Narmadha Valley Project- India. Dam and Hydro power project.

Adverse effects of Deforestation.o Social and Economic effects

• Insecure future to the forest workers.• Re-plantation may lead to loss of quality.• Loss of future market for ecotourism. • Disappearance of aesthetic, recreational and cultural rewards occur. • Social and economic life threat for tribal groups.Environmental effects• Destruction of Biodiversity ( World Wildlife Fund(WWF) definition:

The wealth of life on earth, the millions of plants, animals and microorganisms, the genes they contain and the intricate ecosystem they build into the living environment.)- Deforestation effects extinction of plants and animals and thus destructs the biodiversity.

• Desiccation of previously moist soil.- moist soil becomes dry and crack.

• Moist humid region changes to desert.• No recycling of water.• Less Carbon Dioxide and Nitrogen exchange.• More desertification – UNEP report - Sahara Desert expanded

100sq.km southward between 1958 and 1975.• Soil Erosion• Case Study-( Brazil- Gold prospectors)

Solutions to the problems of Deforestation.

o Reduce the consumption of forest and related products.

o Consciously boycott products of companies involved in

deforestation.

o Seek changes in Forest Policies.

o Environmental conservation may be given importance in school

education.

Reduce Reuse Recycle – 3 R’sThough sound and appear similar, they are distinct elements in the language of resource conservation.

• Reduce:o Lowering consumption is the key to the concept of reducing.o Lowering or eradicating from the start.o Life style- use of public transport, carpooling, walking etc,.o Textile- MLR

• Reuse:o Reuse of materials and items that have reusable qualities. (paper plates –

cutlery)An old shirt may become a car rag.o Though reuse is different from reducing use, when an item is reused,

consumption is reduced as a by-product.o Tannery- Leather meal, glue etc,.

• Recycle:o refers to the process in which an item or its components are used to create

something new.o It is technically a form of reusing, but it refers more specifically to items

that are discarded and broken down into their raw materials.o Plastic bottles are recycled and made into carpet, pathways and benches.

Glass and aluminum are other commonly recycled materials.o e-waste.

Timber ExtractionImpacts:o Fragmentation in remaining forest, damage to the valuable species

and also decrease in biodiversity.o Composition of bird and mammal communities is significantly

modified.o Number of wildlife species is eliminated.o Heavy machinery can compact the soil and destroy vegetation.o High volume harvesting contribute to erosion and reduce species

diversity and regenerative capacity.o In the event of fire, excess organic debris can make forest more

vulnerable to destruction in the event of fire.

UNFAO guidelines – addresses methods to reduce env.impacts in

forestry operations.

Forest Stewardship Council (FSC) – provides framework for

organizations certifying sustainable logging operations.

Classifications of Timber Extractiono Clear felling - complete destruction of the native forest.

o Selective logging – Large individuals of a few commercially

marketable species are selectively harvested.

o Mechanized logging – use of heavy machinery in clear felling and

also in selective logging.

o Hand- logging – adopted in seasonally flooded and permanently

water logged areas for clear felling and selective logging.

o Reduce- Impact logging –

• UNFAO guidelines provides basis for reduced-impact

logging practices.

• Environmental damage can be minimized through selection

of site-sensitive harvesting techniques.

Case study- Chipko Movement

Sunderlal Baghuguna- leader - active in Bhageerathi valley

• People movement in North India to prevent commercial timber

harvesting.

• Unique strategy is “ recognizing trees as valuable” and this

movement followers are literally known as “tree huggers.”

• Man is the butcher of earth.

• Stop construction of dam at Tehri- due to uproot of trees and heavy

flood threat.

MiningIt is act of extracting ore, coal etc., from the Earth.

Exploratory Phase- Less impact: Operational phase- More impact.

Impacts of Mining on Forests and Environment:• Quantum of waste generated is more compared to other natural

extraction processes (Open-pit Mining:)– Contact of water with this waste leads to generation of

contaminated fluids of acidic/alkaline/heavy metal conc. etc,.(pollution of river, soil and groundwater.

– Aid mine drainage (sulphide content more in the waste). This gets aggravated when the rainfall and temperature are high.

Erosion and sedimentation present.Damage to forest cover by mining is less compared with logging.Dust generation- air pollution, surface water pollution, health

problems etc,.Noise pollutionDisruption to aquatic habitats.

Social Damages of Mining

• Appropriation of the land belonging to the local communities.

• Alteration of social relationships

• Destruction of forms of community subsistence and life.

• Social disintegration.

• Radical and abrupt changes in regional cultures.

• Displacement of other present and/or future local economic activities.Case Study: Bougainville Copper Mine.- It is an Island of extent 10000 sq.km. (nearby to Soloman Island)- Colonial Rule-

British/Germany/Australia.- As a UN trusteeship, it unitedgerman and British territiories of Papua and New

Guinea.- Then become Pap New Guinea (PNG) and obtained independence.- Copper mine export accounted for 40% and 17-20% of government revenue.-Till 1972 production of copper ore from mine was carried out. -Environmental damage-copper tailings dumped into the Jaba river.-Compensation was meagre and lead to public agitation like civil war.-Bougainville conflict affects PNG relation with its neighbors.-On May,17,1990, Bo.Interim Governemnt declared independence from PNG.

Dams

• Impounding of water in small dams.

• Development of turbines leads to hydropower and large dams( More than

15m, as per International Commission on Large Dams.)

Purposes of Dam:

• Irrigation( 48%)

• for domestic and industrial supply(15%).

• Generation of Electricity.( 20 % -worldwide and in Europe-40%)

• Flood control( 8%)

• Recreation (4%)

• Inland Navigation and fish Farming (lesser degree)

Benefits of Dam

Problems with Dams.( economic returns, ecology, loss of aquatic

biodiversity, waterlogging and salinity factor)