Evs Ques Paper Nov Dec 2011

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B.E/ B Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER

Common to B.E / B Tech. (Civil Engineering / Computer Science and

Engineering / Information Technology )

Third Semester

ENVIRONMENTAL SCIENCE and ENGINEERING

PART A

1) WHAT ARE THE EFFECTS OF HIV/AIDS ON ENIVRONMENT?

*Large number of death occurs , which affect environment and natural resources.

*Due to large number of deaths, there is loss of labour and level of production

decreases.

*More water is required for maintaining hygiene in AIDS affected locality.*The people affected by HIV, cannot perform work well due to lack of energy and

frequent fever and sweating.

2) WHAT IS HUMAN DEVELOPMENT INDEX (HDI)?

A tool developed by the United Nations to measure and rank countries levels ofsocial and economic development based on four criteria: Life expectancy at birth,

mean years of schooling, expected years of schooling and gross national income

per capita. The HDI makes it possible to track changes in development levels over

time and to compare development levels in different countries.

3)DISTINGUISH BETWEEN RENEWABLE AND NON RENEWABL

RESOURCES?

RENEWABLE RESOURCES NON RENEWABLE RESOURCES

*It is regenerated continuously. *It cannot be regenerated .

*In exhaustible *Exhausted.

*It can be used again and again. * It cannot be used again.

*It pollution free. *It pollutes the atmosphere.*Available in limited amount in

nature.

*Available in unlimited amount in

nature.

* It is developed in a long period. *It is developed in a short period.

*EXAMPLE: wood, solar energy,

wind energy

*EXAMPLE: coal, petroleum ,nuclear

fuel.


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4)WHAT ARE PRODUCERS,CONSUMERS ND DECOMPOSERS?PRODUCERS:

Producers synthesize their food themselves through photosynthesis.

EXAMPLE: All green plants, trees.

CONSUMERS:Consumers are organisms, which cannot prepare their own food and

depend directly or indirectly on the producers.

EXAMPLE:

i) plant eating species

Insects, rabbit , goat ,deer ,cow ,etc;

ii)Animals eating species

Fish, lions, tiger, etc ;

DECOMPOSER:

Decomposers are those organisms which feed on dead organisms plantsand animals and decompose them into simpler compounds.

EXAMPLE:bacteria,fungi etc..

5) WHAT ARE HOT SPOTS BOIDIVERSITY?MENTION CRITERIA FOR

HOTSPOTS?The hot spots are the geographical areas which posses high endemic species.

CRITERIA FOR RECOGNISING HOT SPOTS:

The richness of the endemic species is the primary criterion for recognisinghot spots.

The hot spots should have a significant percentage of specialised species. The site is under threat. It should contain important gene pools of plants potentially useful plants.

6)WHAT DO MEAN BY ENVIRONMENT REFUGES?

Environmental migrants are people forced to migrate away from their homeland

due to sudden or long-term changes to their local environment.

7)WHAT ARE THE GREEN HOUSES GASES AND GREEN HOUSESEFFECT?

GREEN HOUSE EFFECT:The green houses effect may defined as, the progressive warming

up of the earth surface due to planketing effect of manmade co2 in the atmosphere.


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GREEN HOUSE GASES:CO2,CH4,N2O AND CHLORO FLORO CARBON

8) DEFINE GENETIC AND SPECIES DIVERSITY?

SPECIES DIVERSITY

Species diversity is the effective number of different species that arerepresented in a collection of individuals.

The effective number of species refers to the number of equally-abundantspecies needed to obtain the same mean proportional species abundance.

Species diversity consists of two components, species richness and speciesevenness

GENETIC DIVERSITY Genetic diversity, the level ofbiodiversity, refers to the total number of

genetic characteristics in the genetic makeup of a species.

Genetic diversity serves as a way for populations to adapt to changingenvironments

9)WHAT IS MENT BY ENVIROMENTAL ETHICS?

Ethics is the philosophical study of moral values. Environmental ethics is the

application of studies to environment concern. It refers to the issues, principles and

guidelines relating to human interactions with their environment.

10)WHAT IS "E" WASTE?

All type of electronic and electrical wastes is called as Ewaste.

EXAMPLE: Computer, mobile phone, fax machine etc.,

PART B

11. (a) (i) Discuss the Universal model of energy flow in an ecosystems

and explain how the flow of energy follows the I and II law

of thermodynamics
http://en.wikipedia.org/wiki/Species_richnesshttp://en.wikipedia.org/wiki/Species_evennesshttp://en.wikipedia.org/wiki/Species_evennesshttp://en.wikipedia.org/wiki/Species_evennesshttp://en.wikipedia.org/wiki/Biodiversityhttp://en.wikipedia.org/wiki/Geneticshttp://en.wikipedia.org/wiki/Geneticshttp://en.wikipedia.org/wiki/Biodiversityhttp://en.wikipedia.org/wiki/Species_evennesshttp://en.wikipedia.org/wiki/Species_evennesshttp://en.wikipedia.org/wiki/Species_richness


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ANSWER:

The transfer of energy from one trophic level to another trophic level iscalled energy flow.

Energy is the most essential requirement for all living organisms. Solarenergy is the only source to our planet earth. Solar energy is transformed tochemical energy in photosynthesis by the plants (called as primary

producers). Though a lot of sunlight falls on the green plants, only 1% of it

is utilized for photosynthesis. This is the most essential step to provide

energy for all living organisms in the ecosystem.

Some amount of chemical energy is used by the plants for their growth andthe remaining is transferred to consumers by the process of eating.

Thus the energy enters the ecosystem through photosynthesis and passesthrough the different tropic levels (feeding levels).

Energy flow and ThermodynamicsThe flow of energy through an eco system follows the two laws of

thermodynamics.

Ist law of thermodynamicsIt states that, energy can neither be created nordestroyed, but it can be

converted from one form to another.

E.g: Solar energy is converted into chemical energy.

IInd law of thermodynamicsIt states that, when ever energy is transferred, there is a loss of energy

through the release ofheat.

Illustration

This occurs when energy is transformed between tropic levels. There will bea loss of energy (about 80-90%) in the form of heat as it moves from one

tropic level to another tropic level. The loss of energy takes place through

respiration, running, hunting etc

Graphical representation of structure and function of tropic levels of anecosystem, starting with producers at the bottom and each successive tropic

levels forming the apex is known as an ecological pyramids.

In the food chain starting from the producers to the consumers, there is aregular decrease in the properties(ie. Energy, biomass and number of the

organisms).


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Since some energy is lost as heat in each tropic levels, it becomesprogressively smaller near the top..

11a (ii) What are ecological pyramids? Explain why in grass

land ecosystems the pyramids of numbers are upright while in parasitic foodchain it is inverted?

ANSWER:

ECOLOGICAL PYRAMIDGraphical representation of structure and function of tropic levels of an ecosystem,

starting with producers at the bottom and each successive tropic levels forming the

apex is known as an ecological pyramids.

There are 3 types of ecological pyramids.a.The pyramid of Number,

b. The pyramid of Biomass

c.The pyramid of energy.

(a) The Pyramids of Numbers:-It represents the number of individual organisms present in each tropic

levels.

EXAMPLE: A grass land ecosystem

The producers in grasslands are grasses, which are small in size and large innumbers. So the producers occupy lower tropic level (1

sttropic level).

The primary consumers (herbivores) are rats, which occupy the IInd tropiclevel. Since the number of rats are lower when compared to the grasses, the

size of which is lower.

The secondary consumers (carnivores) are snakes, which occupy the IIIrdtropic levels. Since the number of snakes are lower when compared to the

rats, the size of which is lower

The tertiary consumers (carnivores ) are eagles, which occupy the nexttropic level. The number and size of the last tropic level is lowest


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(b) Pyramids of Biomass:-

It represents the total amount of biomass (mass or weight of biologicalmaterial or organism) present in each tropic levels.

The pyramid of Biomass can also be upright (or) inverted.Up right pyramid

EXAMPLE: A forest ecosystem

There is a decrease in the biomass from the lower tropic level to the highertropic level.

This is because the trees (producers) are maximum in the forest, whichcontributes a huge biomass.

The next tropic levels are herbivores (insects, birds) and carnivores (snakes,foxes). The top of the tropic level contains few tertiary consumers (irons and

tigers), the biomass of which is very low

(c) Pyramids of Energy:-

It represents the amount of energy present in each tropic levels. The rate ofenergy flow and the productivity at each successive tropic level.

Pyramid of energy gives the best representation of the tropic relationship andit is always upright.

At every successive tropic level, there is a heavy loss of energy (about 90%)in the form of heat. Thus at each next higher tropic level only 10% of the

energy is transferred. Hence, there is a sharp decrease in energy at each andvery successive tropic level as we move from producers to top carnivores.

11b) (i) Explain different methods of In-Situ conservation of Biodiversity (8)

ANSWER:

In situ conservation involves protection of fauna and flora within its naturalhabitat where the species normally occurs.

Biosphere reserves:-It covers a large area more than 5000 sq.km. It is used to protect species for a long

time. There are about 7 Biosphere reserves.

EXAMPLE:-Nilgiri, Nandadevi

They support maximum number of endangered species and is also useful for

educational and research purposes.


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National park:-

It covers small area about 100500 sqkms within a biosphere. It protectspropagate and develop the wildlife. There are about 80 national parks.

EXAMPLE:- Periyar Tiger

Kaziranga Rhino

Wildlife sanctuaries:-

It is an area which is reserved for conservation of animals only. There are

about 492 wildlife sanctuaries.EXAMPLE:-Mudumalai wildlife sanctuaryTiger, elephant Leopard.

Gene sanctuary:-

It is an area where plants are conserved.

EXAMPLE:- In northern India:-gene sanctuary for citrus.

ADVANTAGES:- It is very cheap & convenient method species get adjusted to

natural disasters.

DISADVANTAGES:- Requires large area & Maintenance of habitat is difficult.

11 b(ii) What are the major causes of man-wildlife conflicts? Discuss

the remedial steps that can curb the conflict ?

ANSWER:

Manwildlife conflicts arises, when wildlife starts causing immensedamage and danger to the man.

Under such conditions it is very difficult for the forest department tocompromise the affected villagers and to gain the villagers support for

wildlife conservation.


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Causes:-

Shrinking of forest cover makes the tiger, lion, elephant, bears to moveoutside resulting in attach of fields and humans.

Human encroachment into the forest area induces a conflict between manand the wildlife.

If animals are injured they have a tendency to attack humans. Usually thefemale wildlife attacks the human if she feels that her newborn cubs are in

danger.

Earlier, forest departments used to cultivate sugarcane, paddy, coconut trees,in the sanctuaries. But now due to lack of such practices the wild animals

move out of the forest for searching food.

The villagers put electric wiring around their crop fields. The elephants getinjured, suffer in pain and start violence.

The cash compensation paid by the government for the damage caused bywild animals is not enough. Therefore the agonized farmers get revengeful

and kill the wild animals.

Earlier there were wildlife corridors for migration seasonally in groups toother area. Due to human settlement, it is disturbed.

Remedial measures:-

Adequate crop compensation, cattle compensation should be provided. Solar powered fencing should be provided.

Tiger conservation project:-

If the animal is hurt vehicle should be arranged to provide hospitality. Fodder, fruit water, should be available within the forest area. The development and construction work in and around forest region must be

stopped.

Cropping pattern must be changed near the forest borders.

12. (a) (i) Discuss various sources of marine pollution. How can youprevent pollution of our oceans?

ANSWER:

. The various coastal development activities have been adversely affecting the sea

grass beds.


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I] Dumping the wastes

Dumping of untreated wastes and sewage into oceans by the coastal towns,cities and industrial units is the most serious issue.

Also, whatever is carried by rivers in their traverse ends up in sea. Thesecarried materials are like large amounts of sewage, garbage, agricultural

discharge, pesticides including heavy metals.

Enormous amount of plastic is also being dumped into sea.Effect:

Many marine birds are affected by gastro-intestinal disorders when theyingest plastic

II] Oil Pollution of Marine Water The greatest damage to water is inflicted by petroleum and its several

products. Oil enters the oceans from cracks in the oil tankers as also because

of the spillage.

Merchant and warships clean their fuel tanks, again resulting in oil spillageinto the ocean. Street cleaning also causes the same effect.

The very heavy portions of the petroleum products tend to precipitate to thebottom or are adsorbed on rock, stone and sand banks resulting in the

inhibition of the life of the hydrobionts.

Even one drop of petroleum is capable of spreading over as a thin film overa large area and isolate the water from contact with atmospheric oxygen.

Effect:

The large spreads of oil films would hamper the photosynthesis and theformation of oxygen.

This in turn inhibits growth of plankton, which is the main source for thehydrobionts inhabiting the water bodies.

Also, all the aquatic animals depend either directly or indirectly on plankton,which forms the basis of the trophic chain.

The surface of water in contact with he shore is usually contaminated withoil, which interferes with the normal development of many hydrobionts.


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Effects of Marine pollution

Presence of heavy metals and organic pollutants cause intense damage inbirds such as thinning of eggshell and the tissue damage of egg.

Oil pollution can cause damage to marine fauna and flora including algae,fish, birds, invertebrates.. About 50,000 to 2,50,000 birds are said to be

killed every year by oil .

Oil spillage in sea water leads to abnormally low body temperature in birdsresulting in hypothermia. Eg. Nearly 150 rare species of bald eagles became

victims when they ingested oil during Exxon Valdez accident.

Oil films are capable of significantly retarding the rate of oxygen uptake bywater.

The continuous oil films inhibit photosynthesis and oxygen formationleading to the debilitating rate of plankton growth.

Hydrocarbons and Benzpyrene tend to accumulate in the food chain andconsumption of fish by man may lead to caner. Detergents used to clean up

the spillage also take their turn causing harm to marine life.

Control Measures of Marine Pollution

A charter of six principles for sustainable management of Marine pollutionhas been recommended by The World Wide Fund for Nature and World

Conservation Union.

Plans for conserving marine biodiversity must be taken into account ofhuman needs.

People should be educated about marine eco systems and the benefitsoffered by them.

Local communities must be made to involve in the protecting andmanagement of their coastal resources

Incentives, both social and economic should be offered for conserving andsustainable use of marine resources

All the oceans of the world are connected is a fact that should be reflectedwhenever policy decisions are taken.

Governments of different regions must manage their own waters and alsoextend necessary cooperation to the neighbouring governments.

Other Control Measures: Industrial units on the coastal lines should be made to equip their industries

with pollution control instruments and efficient treatment facilities.

There must be proper regulation in respect of urban growth near the coasts.


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The needs of the fishermen living on the coasts and depending on marineresources should be accommodated and their grievances alleviated.

Methods of Removal of Oil

Several methods have been devised to deal with oil floating on the sea.

1. Physical Methods

The simplest method is to skim off the oil from the sea surface using asuction device.

Highly absorbing material like polyurethane foam can be used for absorbingthe floating oil. Saw dust and chopped straw may also be used to absorb oil

from sea water.

Coagulation of the oil using chemicals can be an alternate method.2. Chemical Methods(i) Dispersion; (ii) Emulsification and (iii) Usage of chemical additives

Protective Measures:

Some of the protective measures are Only after proper treatment Municipal and Industrial wastes should be

allowed to join the sea.

Periodical analysis for detecting pollution levels should be undertaken forthe costal wastes

Soil erosion in the coastal land should be arrested by suitable and propercontrol techniques.

Recreational beaches must be so maintained as to meet the hygienic andaesthetic standards

12 a ii) How are solid waste classified ? Write the sources of urbanand Industrial solid wastes.

ANSWER:

Types of Solid WastesDepending upon the nature, solid waste s may be broadly classified into two

types:


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1. Urban wastes

2. Industrial wastes.

Sources of Urban and Industrial Solid Wastes

Sources of Urban Wastes:Urban wastes include the following wastes.

(a) Domestic Wastes: It comprises of a variety of materials thrown out from the

homes.

Eg: Food waste, cloth, waste paper, glass bottles, polythene bags, waste metals etc.

(b) Commercial wastes: these include the wastes coming out from the shops,

markets, hotels, offices, institutions, etc.

Eg: Waste paper, packing material, cans, bottle, polythene bags, etc.

(c) Construction Wastes: It includes the wastes of construction materials.

Eg: Wood, Concrete, debris etc.(d) Biomedical wastes: These include mostly the waste organic materials

Eg: Anatomical wastes, infectious wastes, etc.

Classification of Urban Wastes:

(i) Bio-degradable wastes:The urban solid waste materials that can be degraded by micro organisms

are called biodegradable wastes.

Eg: Food, vegetables, tea leaves, egg shells, dry leaves, etc.

(ii) Non-Biodegradable wastes:

The urban solid waste materials that can not be degraded by micro

organisms are called non-biodegradable wastes.

Eg: Polythene bags, scrap metals, glass bottles, etc.

2. Sources of Industrial Wastes:The main sources of industrial wastes are chemical industries, metal and mineral

processing industries.

(i) Nuclear Power Plants: These generate radioactive wastes.

(ii) Thermal Power Plants: These produce fly ash in large quantities.

(iii) Chemical Industries: They produce large quantities of hazardous and toxicmaterials.

(iv)Other Industries: Other industries produce packing materials, rubbish, organic

wastes, acids, alkalis, scrap metals, rubber, plastic, paper, glass, wood, oils paints,

dyes, etc.


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12(b) (i) Briefly describe the sources, effect and prevention of soil pollution (8)

ANSWER:

Types, effects and sources of soil pollution:

Soil pollution results mainly from the following sources:

1. Industrial wastes,

2.Urban wastes

3. Agricultural practices

4. Radio active pollutants

5. Biological agents

1. Industrial Wastes:

Disposal of industrial wastes is the major problem for soil pollution Sources: The industrial pollutants are mainly discharged from the various origins such

as pulp and paper mills, chemical industries, oil refineries, sugar factories,

tanneries, textiles, steel, distilleries, fertilizers, pesticides, coal and mineral

mining industries, drugs, glass, cement petroleum and engineering industries

etc.

Effect: These pollutants affect and alter the chemical and biological properties of

soil. As a result, hazardous chemicals can enter into human food chain from the

soil or water, disturb the biochemical process and finally lead to serious

effects on living organisms.

2. Urban Wastes:

Urban wastes comprise of both commercial and domestic wastes consistingof dried sludge of sewage. All the urban solid wastes are commonly referred

to as refuse.

Constituents of urban refuse: This refuse contains garbage and rubbishmaterials like plastics, glasses, metallic cans, fibres, paper, rubbers, street

sweepings, fuel residues, leaves, containers, abandoned vehicles and other

discarded manufactured products.

Urban domestic wastes though disposed off separately from the industrialwastes, can still be dangerous. This is due to the fact that they are not easily

degradable.


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3. Agricultural Practices:

Modern agricultural practices pollute the soil to a large extent. Earlier daypractice of agriculture consisted of the farmer working very hard to compost

on his own fertilizer from Animal excreta, fallen leaves, soil and other

domestic waste matter. The farmer used to spend large amount of time in the fields with total

commitment and devotion.

As against this, with the advancing agro-technology, the farmer todayemploys huge quantities of chemical fertilizers, pesticides, herbicides,

weedicides etc in order to increase the crop yield.

Apart from these farm wastes, manure, slurry, debris, soil erosion containingmostly inorganic chemicals is said to cause soil pollution.

4. Radioactive Pollutants:

Radioactive substances resulting from nuclear dust explosions and radioact8ive wastes (produced by nuclear testing laboratories and industries)

penetrate the soil and accumulate there, thus causing soil pollution.

Eg:1. Radio nuclides of radium, thorium, uranium, isotopes of potassium (K-40) and

carbon (C-14) are very common in soil, rock, water and air.

2. Explosion of Hydrogen weapons and cosmic radiations induce neutron, proton

reactions by which nitrogen (N-15) produces C-14. This C14

participates in the

carbon metabolism of plants which then gets introduced into animals and human

beings.3. Radioactive waste contains several radio nuclides such as Strontium-90. Iodine-

129, Cesium-137and isotopes of iron which are most injurious. Sr-90 gets

deposited in bones and tissues instead of calcium.

4. Nuclear reactor produces waste containing Ruthenium-106, Iodine-131, Barium-

140 and Lanthanum-140. Cesium-144 along with the primary nuclides Sr-90 and

Cs-137 has a half life of 30 years, while Sr-90 has 28 years. Rain water carries Sr-

90 and Cs-137 and deposits on the soil and they are held firmly with the soil

particles by electrostatic forces. All these radio nuclides so deposited on the soil

emit gamma radiations.

5. Biological Agents:Soil gets large quantities of human, animal and bird excreta constituting the major

source of land pollution by biological agents.


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Eg:1. Manures and digested sludges, if they are applied heavily, could cause serious

damage to plants within a few years. These sludges contain more live viruses and

viable intestinal worms and hence the soil pollution.

2. Apart from the above mentioned excreta materials, faulty sanitation (especially

in our country) municipal garbage, waste water and wrong methods of agricultural

practices also induce heavy soil pollution.

Control measures of soil pollution:

Necessity for high increase in farm activities arise for two reasons.

1. Population growth by leaps and bounds

2. Urbanization decreases in the availability of farm land.

1. Control of soil erosion:

A variety of forestry and farm practices would help in control of soil erosion.

EXAMPLE:(A) Trees may be planted on barren slopes

(B) Instead of shifting cultivation contour cultivation and srip cropping can be

practiced

(C)Terracing and building diversion channels can be undertaken by reducing

deforestation and substituting chemical manures with animal wastes would also

help to arrest soil erosion in the long term. Maintaining soil productivity is vital

and essential for sustainable agriculture.

2. Proper dumping of unwanted materials:

Excess of waste products by man and animals cause chronic disposalproblem.

In India the most commonly used method is open dumping. Controlledtipping method is being followed recently for solid waste disposal.

The surface thus obtained can be used for housing or sports field.3. Production of natural fertilizers:

Excessive use of chemical fertilizers and insecticides should be avoided. Chemical

pesticides shall have to be replaced by Biopesticides.


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EXAMPLE: organic wastes present in animal dung should be used for preparing

compost manure and biogas rather than throwing them wastefully polluting the

soil.

4. Proper hygienic condition:

People should get proper training about good sanitary practices.

EXAMPLE: Lavatories should be provided with quick and effective disposal

methods.

5. Public awareness:

Informal and formal public awareness programmes should be conducted to impart

knowledge and educate people on health hazards because of environmental

pollutionEXAMPLE: mass media, educational institutions and voluntary agencies can take

forward step in achieving this.

6. Recycling and Reuse of wastes:To minimize soil pollution, the wastes such as paper, plastics, metals, glasses,

organics, petroleum products and industrial effluents etcf. Should be recycles and

reused.

EXAMPLE: Industrial wastes should be properly treated at source. Intgrated

waste treatment methods should be adopted.

7. Ban on Toxic Chemicals:

Statutory ban should be imposed on chemicals and pesticides like DDT, BHC etc.,

which are fatal to plants and animals.

Nuclear explosions and the improper disposal of radioactive wastes should be

banned.

12 b(ii) Explain the mitigation measures for landslides.

ANSWER:

1.Unloading the upper parts of the slope.

2.Improving the cultivation in the sloppy region ,the roots of which provide

cohesion and retards the flow of water and its erosion capacity.

3.Steepness of the slope can be reduced by developing benches.

4.Concrete support can be made at the base of the slope.


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5.Draining the surface and the sub surface water from the weak sloppy region .

6.Soil stabilization using some chemicals like quick lime is also effective in weak

areas.

13 (a) Discuss the modern Agriculture and its impacts and problems under

the following heads(i) High yielding varieties (4)

(ii) Fertilizer related problems (4)

(iii) Effect of Pesticides (4)

(iv) Water logging and salinity. (4)

ANSWER:

I.Impacts related to high yielding verities (HYV):

The uses of HYVs encourage monoculture i.e. the same genotype is grownover vast areas.

Incase of an attack by some pathogen, there is total devastation of the cropby the disease due to exactly uniform conditions, which help in rapid spread

of the disease.

II.Fertilizer related problems:

1.Micronutrient imbalance:

Chemical fertilizers have nitrogen, phosphorus and potassium (N,P,K) whichare essential macronutrients.

Excessive use of fertilizers cause micronutrient imbalance For example, excessive fertilizer use in Punjab and Haryana has caused

deficiency of the micronutrient Zinc in the soils, which is affecting

productivity of the soil.

2.Nitrate Pollution:

Nitrogenous fertilizers applied in the fields often leach deep into the soil andultimately contaminate the ground water.

The nitrates get concentrated in the water and when their concentrationexceeds 25 mg/L, they become the cause of a serious health hazard called

"Blue Baby Syndrome" or methaemoglobinemia.

This disease affects the infants to the maximum extent causing even death.


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3. Eutrophication:

A large proportion of nitrogen and phosphorus used in crop fields is washedoff along with runoff water and reach the water bodies causing overnourishment of the lakes, a process known as Eutrophication.

Due to Eutrophication the lakes get invaded by algal blooms. These algalspecies grow very fast by rapidly using up the nutrients.

The algal species quickly complete their life cycle and die thereby adding alot of dead matter.

The fishes are also killed and there is lot of dead matter that starts gettingdecomposed.

Oxygen is consumed in the process of decomposition and very soon thewater gets depleted of dissolved oxygen. This further affects aquatic fauna

and ultimately anaerobic conditions are created where only pathogenicanaerobic bacteria can survive.

Thus, due to excessive use of fertilizers in the agricultural fields the lakeecosystem gets degraded

III.Pesticide related problems:

Thousands of types of pesticides are used in agriculture. The first generation pesticides include chemicals like sulphur, arsenic, lead

or mercury to kill the pests.

They have number of side effects as discussed below:

Creating resistance in pests and producing new pests: About 20 species ofpests are now known which have become immune to all types of pesticides

and are known as "Super pests".

Death of non-target organisms: Many insecticides not only kill the targetspecies but also several non-target species that are useful to us.

Biological magnification: Many of the pesticides are non-biodegradable andkeep on accumulating in the food chain, a process called biological

magnification. This is very harmful.


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Water Logging:

Over irrigation of croplands by farmers for good growth of their crop usuallyleads to water logging.

Inadequate drainage caused excess water to accumulate underground andgradually forms a continuous column with the water table.

Under water-logged conditions, pore-spaces in the soil get fully drenchedwith water and the soil- air gets depleted. T

he water table rises while the roots of plants do not get adequate air forrespiration, Mechanical strength of the soil declines, the crop plants get

lodged and crop yield falls.

In Punjab and Haryana, extensive areas have become water-logged due toadequate canal water supply or tube-well water.

Preventing excessive irrigation, sub-surface drainage technology and bio-drainage with trees like Eucalyptus are some of the remedial measures to

prevent water-logging.

Salinity Problem:

At present one third of the total cultivable land area of the world is affectedby salts.

Saline soils are characterized by the accumulation of soluble salts likesodium chloride, sodium sulphate, calcium chloride, magnesium chloride

etc. in the soil profile.

Their electrical conductivity is more than 4 dS/m. Sodic soils havecarbonates and bicarbonates of sodium, the pH usually exceeds 8.0 and theexchangeable sodium percentage (ESP) is more than 15%.

13b) Explain the basic types of soil erosion and agents responsible for soil

erosion. What are the conservation practices employed to prevent

soil erosion?

ANSWER:

Soil erosion

Soil erosion is defined as the movement of soil components, especiallysurface litter and top soil from one place to another.


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Soil erosion results in the loss of fertility because it is the top soil layerwhich is fertile.

Soil erosion is basically of two types based upon the cause of erosion: Normal erosion or geological erosion: caused by the gradual removal of top

soil by natural processes which bring equilibrium between physical,biological and hydrological activities and maintain a natural balance

between erosion and renewal.

Accelerate erosion: This is mainly caused by man made activities and therate of erosion is much faster than the rate of formation of soil. Overgrazing,

deforestation and mining are some important activities causing accelerated

erosion

There are two types of agents which cause soil erosion. They are

1. Climatic agents2. Biotic agents

1.Climatic AgentsWater and Wind:

Water affects soil erosion in the form of rain. Water induced soil erosion is of following types:

Sheet erosion: When there is uniform removal of a thin layer of soil from a large

surface area, it is called sheet erosion.

Rill erosion: when there is rainfall and rapidly running water produces finger-

shaped grooves or rills over the area, it is called rill erosion.

Gully erosion: When the rainfall is very heavy, deeper cavities or gullies are

formed, which may be U or V shaped.

Slip erosion: This occurs due to heavy rainfall on slopes of hills and mountains.

Stream bank erosion: During the rainy season, when fast running streams take a

turn in some other direction, they cut the soil and make caves in the bank

Wind erosionIt is responsible for the following three types of soil movements:

a.Saltation:

This occurs under the influence of direct pressure of stormy wind and thesoil particles of 1-1.5 mm diameter move up in vertical direction.


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b.Suspension:

Here fine soil particles (less than 1mm diameter) which are suspended on theair are kicked up and taken away to distant places.

c.Surface creep:

Here the large particles (5-10 mm diameter) creep over the soil surfacealong with wind.

2.Biotic Agents:

Excessive grazing, mining, and deforestation are the major biotic agentsresponsible for soil erosion.

Deforestation without reforestation, overgrazing by cattle, surface miningwithout land reclamation, irrigation techniques that lead to salt build- up,

water logged soil, make the top soil vulnerable to erosion.

Soil conservation practices:

In order to prevent soil erosion and conserve the soil the followingpractices are employed.

1.Conventional till farming:

In traditional method the soil is broken up and smoothed to make a plantingsurface.

This disturbs the soil and makes it susceptible to erosion. Conservational till farming, popularly known as no-till-farming causes

minimum disturbance to the top soil.

Here special tillers break up and loosen the subsurface soil without turningover the top soil.

The tilting machines make slits in the soil and inject seeds, fertilizers, andlittle water in the slit, so that crop grows successfully.

2.Contour farming:

On gentle slopes, crops are grown in rows across, rather up and down. This practice is knows as contour farming. It helps to hold soil and slow down loss of soil through run-off water.

3.Terracing:

It is used on still steeper slopes are converted into a series of broad terraceswhich run across the contour.

Terracing retains water for crops at all levels and cuts down soil erosion.4.Strip cropping :


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Here strops of crops are alternated with strips of soil saving crops likegrasses or grass- legume mixture.

Whatever run-off comes from the cropped soil is retained by the strip ofcover- crop and this reduces soil erosion.

5.Alley cropping:

It is a form of intercropping in which crops are planted between rows oftrees or shrubs. This is also called Agro forestry.

Even when the crop is harvested, the soil is not fallow because trees andshrubs still remain on the soil holding the soil particles and prevent soil

erosion.

6.Wind breaks or shelterbelts:

The trees are planted in long rows along the cultivated land boundary so thatwind is blocked.

The wind speed is substantially reduced which helps in preventing winderosion of soil.

14. (a) (i) What do you mean by sustainable measures to attain sustainability

ANSWER:

SUSTAINABLE DEVELOPMENTIt is defined as meeting the needs of the present without compromising the

ability of future generation to meet to meet their own needs.

Approaches For Sustainable Development:The following approaches (or) methods are proposed for the build up of

Sustainable Development.

1. Developing appropriate technology: it is the one approach which is locally

adaptable, eco-friendly, resource-efficient and culturally suitable. It uses local

labours, less resources, and produces minimum waste.

2. Reduce, Reuse, Recycle (3 R ) approach: This approach insists on optimum

use of natural resources, using it again and again instead of throwing it on

wasteland or water and recycling the material into further products. It reduces

pressure on our natural resources and reduces waste generation and pollution.


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3. Providing environmental education and awareness: By providing

environmental education and awareness, the thinking and attitude of people

towards our earth and the environment can be changed.

4. Consumption of Renewable resources: In order to attain sustainability, it is

very important to consume the natural resources in such a way that the

consumption should not exceed the regeneration capacity.

5. Conservation of non-renewable resources: For sustainability non-renewable

resources should be conserved by recycling and reusing.

6. Population control: Sustainable development can be made by controlling

population growth.

14 a (ii) Discuss the salient features of

(1) Wild life (protection) Act (4)

(2) Forest (conservation Act). (4)

ANSWER:

I .WILDLIFE PROTECTION ACT:

SALIENT FEATURES

1. The act covers the rights and non-rights of the forest dwellers.

2. It prevents the biodiversity.

3. It provides restricted grazing in sanctuaries but prohibited in natural parks.

4. It helps to maintain essential ecological process and life supporting systems.

5. It ensures the continuous use of the species.

6. It also prohibits the collection of non-timber forests.

7. The rights of forest dwellers recognized by the Forest Policy of 1988 are taken

away by the Amend Wildlife Act of 1991.

II. FOREST CONSERVATION ACT:

SALIENT FEATURES

1. The reserved forests shall not be diverted or deserved without the

priorpermission of the central government.


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2. It protects and conserves the forest .

3. Any illegal activity within the forest area can be immediately stopped under act.

4. It ensures the judicial use of the forest products.

5. The land has been notified or registered or forest land may not be used for other

non-forest purposes.

14(b) Discuss the objectives and various measures of wasteland

reclamation and development.

ANSWER:

Waste land reclamation

Waste land:The land which is not in useunproductive , unfit forcultivation another economic uses.

About 20% of the geographical area of the India is waste lands.Types of waste land:

1.Uncultivable waste land :

These lands cannot be brought under cultivation.

Eg:Barren rocky areas, hilly slopes, sandy desserts.

2.Cultivable waste land-:

These are cultivable but not cultivates for more than 5 years .Cultivable lands are

used for agricultural purposes.

Eg: Marsh lands, saline land etc.,

Causes for waste land formation:

Soil Erosion, Deforestation, Water logging, Salinity Excessive use of pesticides Construction of dams Over-exploitation of natural resources Sewage and industrial wastes Mining activities Growing demands for fuel, fodder wood and food causes degradation and

loss of soil productivity.

Increasing demand of firewoods


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Objectives of waste land reclamation

To improve the physical structure and quality of the soil

To prevent soil erosion,flooding and landslides. To avoid overexploitation of natural resources To conserve the biological resources and natural ecosystem. To improve the availabily of good quality of water for agricultural purposes

and industrial opertations.

To provide a source of income to the rural poor. To supply fuel,fodder and timber for local use.

Methods of waste land reclamation

1.DRAINAGE:

Excess water is removed by artificial drainage. This process is called water-logged soil reclamation.

2.LEACHING:

Leaching is the process of removal of salt from the salt affected soil byapplying excess amount of water.

Leaching is done by dividing the fields in small plots. In continuous leaching 0.5-1.0 cm water is required to remove 90% of

soluble salts.

3.IRRIGATIONAL PRACTICES:

High frequeny irrigation with controlled amount of water helps to maintainbetter water availability in the land.

4.GREEN MANURES AND BIOFERTILIZERS:

Application of green manure is found to improve the saline soils.


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5.APPLICATION OF GYPSUM:

Soil sodicity cab be reduced with the gypsum. Calcium of gypsum replaces sodium from the enchangable sites .

This process converts the clay back into calcium clay.

6.AFFORESTATION PROGRAMMES:

The National Commission of Agriculture (NCA) has launced severalafforestation schemes.

The National Development Board has decided to bring 5 million hacres ofwastye land annually for firewood and fodder plantation.

7.SOCIAL FORESTRY PROGRAMMES:

These programmes involve strip plantation on road,canal-sides,degradedforests lands etc..

15. (a) (i) How can age - structure pyramids serve as useful tool for predicting

population growth trends of a nation? Explain with examples.

ANSWER:

Variation of population based on Age Structure:

Classification of population based on its age structure leads to three classes.

Pre-productive population (0-14 years) Reproductive population (15-44 years) Post reproductive population (above 45 years)

(i) Pyramid shaped variation of population: (increase)

Eg.: India, Bangladesh, Ethiopia, Nigeria etc.

In these countries the pre-productive population is more (high) (0-14 years), the

post reproductive population (above 45 years) is less and the reproductive


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population (15-44 years) is in the middle. All together form a pyramid shaped

projection. However the large number of young age people will soon enter into

reproductive age group population (15-44) which would increase the population

growth. The less number of old age people indicates lower loss of population due

to death.

(b) Bell shaped variation of population: (stable)

Eg.: France, USA, UK, Canada etc.

In these countries, the pre-productive age group population (0-14 Years) and

reproductive age group population (15-44 years)are more or less equal. Therefore

the people entering into the reproductive age group will not change the population

and thus the population growth will be stable. The chart when drawn would havethe shape of a bell.


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(c) Urn shaped variation of population (decrease)

Eg.: Germany, Italy, Sweden, Japan etc.

The pre-productive age group population (0-14 years) of these countries is

smaller than the reproductive age group population (15-45 years). Hence in the

next ten (10) years, the number of people in the reproductive age group will be less

than present day, resulting in a decrease in population growth. The chart when

drawn would have the shape of a Urn.

IMPORTANCE OF AGE STRUCTURES IN PREDICTING POPULATION

OF THE GROWING NATION

i. Age structure is an expression of the number of people in a total population

found in each age group.

ii. Generally the population is categorised into three broad age groups: the young

(usually under 14), adults (usually 15 to 59 inclusive) and the aged (60 and over).

iii. It is said that age structure reflects the demographic and socio-economic historyof a population over a period of about a century. Certainly it is the result of various

and interrelated factors such as fertility, mortality and migration, which have

operated during the lifetime of the oldest inhabitants.

iv. Age structures of particular countries are most commonly shown

diagrammatically, using age-sex pyramids. Four main types have been identified:


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1. A progressive age structure of population is one in which both birth and death

rates are high.

i. Children = 45-55% and aged = 5-10% of the total population

ii. High fertility due to social, cultural and perhaps religious and economic

condition. High level of mortality due to poor living conditions, bad diets and little

medical aid,

iii. Developing countries such as Bolivia and Angola.

iv. Pyramid shape - Typical of first stage of demographic transition with very

broad base but rapidly tapering.

2. A regressive age structure of population is one in which birth and death rates are

low and declining.

i. Children = 30% and aged = above 15% of the total population.

ii. Regions of high living standards, education and social awareness accompanied

by good food and medicine. Ex-developed countries (especially those of Western

Europe)iii. Pyramid shape - Narrower base with equally wide subsequent age groups

tapering off gradually.

3. A stationary age structure of population is one in which birth and death rate

unchanged over a long period of time.

i. Children = 35-40% and aged - about 10%, of the total population. Ex-Japan.

ii. Pyramid shape - Regularly tapering.

4. An intermediate age structure may vary in character and is most common in

countries that are passing through stages of development ex- USA. Such countries

may once have had progressive structures and may, in future, have regressive

structures.

15a(ii) What are the impacts of population explosion over the environment?

ANSWER:

1.Population explosion leads to environmental degradation.

2.Many of the renewable resources like forests,grass,lands are also under threat.

3.The increase in population will increase disease, economic inequity and

communal war.

4.Over crowding of cities leads to development of slums.5.Unemployment and low living standards of the people.

6. Lack of basic amenities like water supply and sanitation,

education ,health etc..

7.Population explosion causes over exploitation of natural resources. Therefore

there will be shortage of resources to the future generations.

8.Population explotion will lead to poverty.


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15(b) Discuss the role of Information Technology in Environment and

Human health

ANSWER:

Information Technology plays a very important and key role in human health. It

has changed the human life style completely.

Many health organizations are turning to package solution of IT for streamlining

service oriented work in an effective manner.

The health service technology mainly comprises of three systems. They are:

Finance and Accounting Pathology Patient administration: clinical system.

Application of Information Technology in health services

With the help of Information Technology packages, the vast data regardingbirth and death rates, immunization and sanitation programmes are

maintained more accurately

It helps the doctor to monitor the health of the people effectively. The information regarding the outbreak of any of the epidemic diseases canbe conveyed easily. On-line help of expert Doctors can be availed to provide better treatment and

services to the patient.

With a central control system the hospital can run effectively. Drugs can their replacement can be administered efficiently.

SOFTWARES FOR ENVIRONMENTAL EDUCATION

Many softwares are developed to improve our human health .They are as follows.

1. Remote sensing: Remote sensing is any method refers to gather information about an object

without actually coming in contact with it.


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Any force field like acoustic gravity ,magnetic, electromagnetic etc couldbe used for remote sensing, covering various disciplines extending from

laboratory to astronomy

Component- A platform, aircraft, A balloon, rocket, and satellite.

Functions:

Origin of electromagnetic energy Transmission of energy Interaction of energy Detection of energy Preprocessing of data Data analysis and interpretation Integration and other applications

APPLICATIONS:In agriculture, forestry, land cover, water resources

2.Data Base-

Collection of inter related data on various subjects. In computer ,the information of the database is arranged in a systematic

manner that is easily manageable and can be very quickly retrieved.

APPLICATIONS:

1.Ministry of environment and forest

They are compiling a database on various biotic communities.

Database is also available for diseases like HIV/AIDS ,Malaria, Fluorosis, etc..

2.National management information system

They are compiling R&D projects along with information about research scientists

and personnel involved.

3.Environmental information system

It functions in 25 centres all over the country.They generate a database in areas like pollution control.clean technologies,remote

sensing,biodiversity,environmental management,desertification etc..


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3.Geographical information system:

GIS is a technique of superimposing various thematic maps using digital data

on a large number of inter-related species.

Application:

Thematic maps are super imposed using softwares. Interpretation of polluted zones To check unplanned growth and related environmental problems

4.Satellite data:

Helps in providing reliable information and data about forest cover Provide information about forecasting weather Reserves of oil , minerals can be discovered.

5.WORLD WIDE WEB:More current data is available on world wide web.

APPLICATIONS:

Online learning Digital files or photos, animations on environmental studies.

Role of information technology in human health:

Information technology plays a vital role in human health. It changed thehuman life style completely.

Many health organizations are turning to package solution of IT forstreamlining service oriented work in effective manner.

The health service technology mainly involves three systems

Finance and accounting Pathology Patient Administrationclinical system.

APPLICATIONS

Data regarding birth and death rates To monitor the health of the people effectively


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The information regarding the outbreak of epidemic diseases. Online Consultation Drugs and its replacement With central control system the hospital can run effectively.

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Evs Ques Paper Nov Dec 2011

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Transcript of Evs Ques Paper Nov Dec 2011