DHANALAKSHMI COLLEGE OF ENGINEERING, CHENNAI

DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING

GE6351 ENVIRONMENTAL SCIENCE AND ENGINEERING

UNIT – 3

NATURAL RESOURCES

PART-A

1. How is nitrogen fixed in soil?(A/M-2017)

Eutrophication is the enrichment of water by the addition of nutrients like Nitrogen and

Phosphorous. The extra nutrients encourage the growth of algal blooms. These algae eventually die and

decompose, removing the oxygen from the water and it causes the death of fish. This process is called

eutrophication.

2. write any two problems caused by high saline soils.(A/M-2017)

Harmful effects on plant growth and yield.

Damage to infrastructure such as roads, bricks, corrosion of pipes and cables.

Reduction of water quality.

Sedimentation problems.

Soil erosion.

3. Mention any two environmental effects of mining for mineral resources. (M/J-2016)

Loss of Vegetation

Pollution

Loss of Biodiversity

Loss of Aquatic Life

4. What are the reasons for land degradation? (M/J-2016)

Over-grazing by animals

By Deforestation.

By Mining.

Natural causes such as running water, glaciers, wind etc.

Pollution by industries.

By Urbanization.

By Irrigation.

Increased use of Fertilizers and Pesticides.

Overpopulation.

5. Define Sustainable lifestyle In less developed countries (N/D-2016)

Population is very high in less developed countries, but they are using 12% of its natural

resources. Their income is nearly 15% of total global income. They have very low industrial

growth. They are struggling with their large population and poverty problems. They are consuming

too low natural resources leading to unsustainability.

6. What is biogas? Mention its uses. (N/D-2016)

Bio gas is primarily methane (CH4) and carbon dioxide (CO2) and may have small amounts of

hydrogen sulfide (H2S), moisture and siloxanes.

As a fuel for boilers and heaters.

As a fuel providing heat for Chilling/Refrigeration.

As a fuel for internal combustion engines, micro turbines, fuel cells.

7. What are renewable and non-renewable energy resources?(A/M2015)/ (N/D2015)/ (N/D2014)

The resources that is capable of being regenerated by ecological processes within a reasonable

time period. They have the potential to renew themselves.

Examples: Soil, Water, Air.

These resources are not capable of being regenerated by ecological processes.

Examples: Minerals, Coal, Oil.

8. What is desertification?(A/M2015)

Progressive destruction or degradation of a grass land or an already arid land into a desert is

known as desertification. Such actions include overgrazing, repeated burning, intensive farming

and stripping of vegetation for firewood.

9. What do you mean by land degradation? (N/D2015)

Land degradation is the process of deterioration of soil or loss of fertility of soil.

Humans change clear land for agriculture and mining, urban and industrial development and for

timber.

10. What are the energy needs procured for India?.[M/J-2014]

Energy means the capacity or power to do work, such as the capacity to move an object by the

application of force. The various forms of energy are electrical, mechanical, chemical, thermal or

nuclear and can be transformed from one form to another. It is measured by the amount of work

done, usually in joules or watts.

Based on the usage, the energy resources can be classified into two types:

1. Renewable energy resources

2. Non renewable energy resources

11. What do you mean natural resources? Give examples.[M/J-2014]

Natural resources are the naturally occurring sources which provide valuable materials.

Natural resources provide wealth to an country economy. Man has overexploited the natural

resources which causes environmental problems such as acid rain, greenhouse effect, landslides,

depletion of ozone layer and other health problems. Environmental problems are corrected only

through proper awareness.

12. What are renewable resources? [N/D-2014]

The resources that is capable of being regenerated by ecological processes within a reasonable

time period. They have the potential to renew themselves.

Examples: Soil, Water, Air.

13. Define the term landslide. [N/D-2014]

The rapid downward and outward movement of sliding of a mass of earth and rock.

PART – B

1. With the help of a neat diagram explain the production of biogas & its uses. (A/M-2017,M/J-2016)

,A/M2015,N/D2014)

Biogas (methane) produced by the process of anaerobic digestion of organic material by

anaerobes.

Biogas is produced by anaerobic digestion (in the absence of oxygen) with anaerobic

bacteria or fermentation of biodegradable materials such as manure, sewage, municipal waste,

green waste, plant material and crops.

Production of bio-gas consists of the following steps,

Manure collection

Anaerobic digestion

Effluent storage

Sludge removal

Manure Digestion Biogas Electricity

Manure collection:

Manure is easily collected on dairy farms.

The composition of manure varies according to feed rations and different farm

management practices.

The amount of manure depends on the type, weight, and number of animals, the feed ration, and the

degree of confinement

Anaerobic Digester

The main components of a farm-size digester system are slurry preparation area, manure

pump or other loading method, and effluent tank.

The components of digester should

- be arranged to minimize heat loss.

- provide a simple flow path for material

- be automated as possible, and

- be easily available for maintenance and repairs.

All materials in contact with the manure or biogas should be corrosion resistant.

All pipes and gas lines should be made large enough to provide access for cleaning devices.

For continuous production of biogas, slurry is supplied continuously by batches.

Anaerobic digestion

Anaerobic digestion is a series of biological processes in which microorganisms break down

biodegradable material in the absence of oxygen.

The digestion process begins with bacterial hydrolysis of the manure.

Acidogenic bacteria then convert the sugars and amino acids into carbon dioxide, hydrogen,

ammonia, and organic acids.

Acetogenic bacteria convert the resulting organic acids into acetic acid, along with additional

ammonia, hydrogen, and carbon dioxide.

Finally, methanogens convert these products to methane and carbon dioxide.

Optimum gas production occurs in two temperature ranges. Mesophilic bacteria thrive in

temperatures around 95°F (35°C), and thermophilic bacteria in the 120°F to 140°F (49°C–

60°C) range.

Effluent Storage

The effluent flows through an overflow pipe into a covered manure pit.

The organic content of the processed manure is reduced and stabilized

Advantages

Eco-friendly, renewable resource.

Waste products are biodegradable.

No greenhouse gas emission.

Disadvantages

Not sustainable.

Uses of biogas:

As a fuel for boilers and heaters.

As a fuel providing heat for Chilling/Refrigeration.

As a fuel for internal combustion engines, micro turbines, fuel cells.

Lighter than air and it produces twice as less calories by combustion with equal volume of natural

gas.

A mitigation atmospheric methane concentration reduces impacts on global climate change.

2. What are the effects of deforestation?(A/M2017,N/D-2016,A/M2015,N/D 2015)

Deforestation is the destruction of forest resources due to natural and man – made activities.

Effects:

1. Shifting of people

Due to deforestation, migration of people from one area to another to meet their

requirements.

2. Loss of Biodiversity

Deforestation on a huge scale results in loss in biodiversity and on a natural global scale is

known to cause the extinction of many species

3. On Nutrient cycles

Disturb the Hydrological Cycle and hence makes the land to lose its fertility.

4. Changes in climate

The temperature will increase and loss in humidity will occur.

5. Increase in Floods and Landslides

Floods and Landslides occur due to the destruction of trees.

6. Loss of wood

By cutting the trees, the wood resources will become scarce .

7. Loss in economy

Destroying medicinal plants leads to the loss in country economy.

8. Affects Global Warming

Deforestation will bring greater effects in climate. The emission of carbon dioxide will result

in the Global Warming.

9. Loss of forest products

The products of forest will greatly depleted due to the sudden destruction of trees.

10. On Pollution

Trees are the major pollution controllers. When deforestation occurs, the air pollution will not

be controlled.

11. Soil degradation

Deforestation makes the land infertile.

3. Write informative notes on modern agriculture. (A/M2017,N/D2015,M/J 2014, N/D-2016,M/J-

2016,N/D-2014)

Modern Agriculture involves machines and use of artificial fertilizer and nowadays using many

modern techniques to yield many crops in small amount of land.

1. Impacts of Fertilizer

Micronutrient Imbalance

A micronutrient disorder may occur when the nutrient level is deficient or in excess. Most

of the commercially prepared fertilizers only include the macronutrients like Nitrogen,

Phosphorous and Potassium. This leads to the micronutrient (Eg. Zinc) imbalance.

Eutrophication

Eutrophication is the enrichment of water by the addition of nutrients like Nitrogen and

Phosphorous. The extra nutrients encourage the growth of algal blooms. These algae

eventually die and decompose, removing the oxygen from the water and it causes the death of

fish. This process is called eutrophication.

Blue baby syndrome

Blue baby syndrome occurs when nitrates are used in high levels (Nitrate pollution) for

agricultural purposes. It is caused when infant’s blood is unable to carry enough oxygen to

body cells and tissue. Due to the increase in methemoglobin level in the blood, methemoglobin

is converted to hemoglobin, the oxygen-carrying enzyme in the blood, by a red blood cell

enzyme called methemoglobin reductase. Infants under the age of six months have little

methemoglobin reductase in their systems. An excess of methemoglobin leads to death.

Groundwater pollution

The main environmental problem associated with fertilizer use is contamination of

groundwater with nitrates and phosphates. High nitrate levels in drinking water are considered

to be dangerous to human health.

Soil acidity

Soil acidity occurs due to the production of organic acids by decomposing organic matter.

2. Impacts of Pesticides

Pesticides are used almost everywhere, not only in agricultural fields, but also in homes,

parks, schools, buildings, forests and roads. Pesticides are substances that kill weeds (herbicides),

insects (insecticides), fungus (fungicides), rodents (rodenticides) and others.

First-Generation Pesticides

First-generation pesticides consist of inorganic and organic compounds. Minerals such as

arsenic, mercury and lead are inorganic compounds, were used as early pesticides.

The minerals persist and accumulate in the soil until the levels become so high. Hence it

makes the soil infertile.

Second-Generation Pesticides

Second-generation pesticides are created synthetically. These pesticides are usually

used to kill a particular target pest. They produce a number of side effects. It also kills the other

organisms like beneficial insects, birds, earthworms, fish in or around thecrop fields, causing loss of

biodiversity, deaths of wild life and death of farm animals.

Examples of Second Generation Pesticides

Chlorinated hydrocarbons – Dichlorodiphenyltrichloroethane (DDT), Endosulfan

Organophosphates – Dimethoate, Malathion

Carbamates – Aldicarb, Carbaryl

Producing New pest

Pesticides kill not only the pests but also the natural enemies of these pests. It disrupts the

natural control mechanisms. This creates the problems in agriculture.

Biomagnification

Biomagnification is a process in an ecosystem by which higher concentrations of a

particular chemical, such as DDT are reached in organisms that higher up the food chain. As a result

of biomagnification, organisms at the top of the food chain generally suffer greater harm from a

persistent toxin or pollutant than those at lower levels.

Risk of Cancer

Genetic damage, reproductive problems and cancer effects are just some of the risks

associated with pesticides.

Reduction of beneficial species

Animals which interact with the targeted pest can also be affected by the chemical application. It

results in the loss of biodiversity of an area and affect natural biological balances.

4. Write a note on (1) use of fertilizers and pesticides (2) soil salinity and problems. (N/D-2016,M/J-

2016,N/D-2014)

Impacts of Fertilizer

Micronutrient Imbalance

A micronutrient disorder may occur when the nutrient level is deficient or in excess. Most of the

commercially prepared fertilizers only include the macronutrients like Nitrogen, Phosphorous and

Potassium. This leads to the micronutrient (Eg. Zinc) imbalance.

Eutrophication

Eutrophication is the enrichment of water by the addition of nutrients like Nitrogen and

Phosphorous. The extra nutrients encourage the growth of algal blooms. These algae eventually die and

decompose, removing the oxygen from the water and it causes the death of fish. This process is called

eutrophication.

Blue baby syndrome

Blue baby syndrome occurs when nitrates are used in high levels (Nitrate pollution) for

agricultural purposes. It is caused when infant’s blood is unable to carry enough oxygen to body cells and

tissue. Due to the increase in methemoglobin level in the blood, methemoglobin is converted to

hemoglobin, the oxygen-carrying enzyme in the blood, by a red blood cell enzyme called methemoglobin

reductase. Infants under the age of six months have little methemoglobin reductase in their systems. An

excess of methemoglobin leads to death.

Groundwater pollution

The main environmental problem associated with fertilizer use is contamination of groundwater

with nitrates and phosphates. High nitrate levels in drinking water are considered to be dangerous to

human health.

Soil acidity

- Soil acidity occurs due to the production of organic acids by decomposing organic matter.

Salinity is the saltiness or dissolved salt content (such as sodium chloride, magnesium and

calcium sulfates and bicarbonates) of a water body. It is the accumulation of salts in the water

bodies which was caused due to evaporation.

Causes of Soil Salinity

High levels of salt in the water.

Climatic trends that favour accumulation.

Human activities such as land clearing, agricultural activities and the salting of icy roads.

Poor drainage.

Effects of Salinity

Harmful effects on plant growth and yield.

Damage to infrastructure such as roads, bricks, corrosion of pipes and cables.

Reduction of water quality.

Sedimentation problems.

Soil erosion.

Control of Salinity

By leaching soluble salts out of soil, with excess irrigation water.

By using sub-surface drainage system, the salt water is flushed out slowly.

5. Explain bioconversion of pollutants with examples. (M/J-2016)

Bioconversion of pollutants

Bioconversion is a process of converting the waste into useful sources of energy.

Bioconversion of waste materials helps in the reduction in environmental pollution.

Biodegradation benefit our environment since it involves low capital and energy cost.

Bio surfactants are surface active agents derived from biological sources.

1. Enzymatic hydrolysis

Switch grass for example, is mixed with strong enzymes which convert a portion of cellulosic

material into sugars which can then be fermented into ethanol.

2. Syn gas

Syn gas contains mostly carbon monoxide and hydrogen and it is converted into usable

products through bacteria or other catalysts.

3. Grub Composting

Grub composting is a process in which the organic waste is converting into high quality

feedstuff and oil rich material for the biodiesel industry.

6. Discuss the impact of mining on environment and human health.(A/M2015)

Effects of Mining on Environment

Loss of Vegetation

Mining techniques caused irreversible damage to trees, birds and animals.

Large scale deforestation takes place.

Loss of Aquatic Life

Release of toxic chemicals into the water is obviously harmful for the flora and fauna of the

water bodies. During mining, sometimes mercury enters the food chain through aquatic

animals.

Cyanide, which is highly poisonous, is used to separate gold from sediment and rock. If

cyanide is released into the environment, it causes the damage of aquatic life.

Effects of mining on Land Loss of Biodiversity

Forests provide home to a large number of organisms. Mining leads to loss of habitat of

large number of animals.

Pollution

Mining changes the chemical composition of the land. It changes the soil fertility.

Effect on Water Pollution

Chemicals like mercury, cyanide, sulfuric acid, arsenic and methyl mercury are used in

various stages of mining are released into nearby water bodies. They cause water

pollution.

Spread of Disease

Water-borne diseases are caused due to the stagnant of water in the pits created during

mining

7. Explain the stages in desertification. (N/D-2016)

DESERTIFICATION

Progressive destruction or degradation of a grass land or an already arid land into a

desert is known as desertification. Such actions include overgrazing, repeated burning, intensive

farming and stripping of vegetation for firewood.

Causes of Desertification

1. Deforestation

- This directly leads to lower rainfall and higher temperatures.

2. Climate change

- Formation of desert may also take place due to climate change, i.e., failure of monsoon,

frequent drought.

3. Mining

- Mining causes deforestation, which may ultimately result in desertification. It causes

disruption in the water table and circulation of ground and surface water. The habitat of a

lot of organisms is also destroyed by mining.

4. Pollution

- Excessive use of fertilizers and pesticides and disposal of toxic water into the land also

leads to desertification.

5. Over Cultivation

- Growing too many crops, year after year on the same place of land damages the soil

structure and reduces the soil fertility.

6. Overgrazing

- The cattle, sheep, goats and other animals take away the vegetation cover and expose

the bare soil.

-

7. Poor irrigation

- This can make the ground too salty. (Salinisation)

8. Drought

- This can damage the vegetation.

Consequences of Desertification

Economic losses

Desertification causes a drop in biological productivity and a decline in economic

productivity.

Major threat to biodiversity

It adversely affects the lives of wild species, domestic animals, agricultural crops and

people.

Deterioration of land resources

Land gets destructed continuously.

Decrease plant nutrient in the soil

The reduction of plant cover which is caused due to desertification causes reduction in

the quantity of humus and plant nutrients in soil.

Steps to reduce desertification

Reduce overgrazing and deforestation.

Limit human activities such as destructive forms of planting, irrigation and mining that

leave soil barren.

Plant more trees and grasses to hold water.

8. What are renewable and non-renewable energy resources? Why are non-renewable energy

Resources preferred for energy utilization now-a-days? What are advantages and

disadvantages of harnessing non-renewable energy resources? (M/J-2016)

The resources that is capable of being regenerated by ecological processes within a

reasonable time period. They have the potential to renew themselves.

Examples: Soil, Water, Air.

These resources are not capable of being regenerated by ecological processes.

Examples: Minerals, Coal, Oil.

COAL:

Coal is a fossil fuel like oil and gas. Fossil fuels are all formed out of organic matter

deposited, decomposed and compressed, storing all the carbon involved under the earth's surface

for millions of years. Coal is the product of compression and heating of organic matter under the

ground over a long period of time.

Coal is a highly carbonaceous matter and it is composed of C, H, N and O besides non-

combustible inorganic matter.

Classification of Coal

Coal is classified on the basis of rank or degree of alternation various types are,

Wood Peat Lignite Bituminous coal Anthracite

The progressive transformation of wood to anthracite results in

1. Decrease in moisture content.

2. Decrease in hydrogen, oxygen, nitrogen and sulphur contents.

3. Increase in carbon content.

4. Decrease in volatile matter content.

5. Increase in the calorific value.

Coal energy is an affordable energy source because of the coal’s stable price compared

to other fuel sources.

Coal is easy to burn.

Coal produces high energy upon combustion.

Coal energy is inexpensive.

Coal is abundant.

Coal energy is a reliable energy source.

Disadvantages of using coal to produce electricity

Coal energy produces large amount of carbon dioxide which leads to global warming and

climate change.

The burning of coal is not environmental friendly because it produces harmful byproducts

and gas emissions such as sulfur dioxide, carbon dioxide and nitrogen oxide that causes

pollution to the environment including acid rain.

Coal energy is a nonrenewable energy source.

9. What is over utilization of water resources? (N/D-2016,M/J-2014)

Due to the growth of human population, there is an increasing need for larger amount of

water to meet the basic needs. The over-utilization of water occurs at various levels.

The problems caused due to the over utilization of water are as follows:

(i) Decrease of groundwater levels

Due to increased usage of groundwater, the groundwater level decreases.

The over utilization of underground and surface water change our freshwater

ecosystems.

(ii) Intrusion of salt water

In coastal area, over exploitation of groundwater would lead to rapid intrusion of salt

water from the sea. As a result, water cannot be used for drinking and agriculture

purpose.

(iii) Water logging

When excessive irrigation is done with brackish water, it raises the water table gradually

leading to water-logging and salinity problems.

(iv) Loss of integrity of freshwater ecosystems

Human activities for infrastructure development like creation of dams, land conversion,

etc., are responsible for this loss of integrity of freshwater ecosystems. Water quality and

quantity, fisheries, habitats, etc., are at risk due to this loss of integrity.

(v) Risk to ecosystem functions

Population and consumption growth increases water pollution. Virtually all ecosystem

functions including habitat, production and regulation functions are at risk.

(vi) Depletion of living resources and biodiversity

Overharvesting and exploitation causes groundwater depletion, collapse fisheries.

Production of food, quality and quantity of water and supply of water gets badly affected

by these depletions of living resources and biodiversity.

10. Write note on:

(1) Food resources (A/M2015)

Food is an essential requirement for all living beings. The resources that are used as food or

provided food for organisms are called as Food resources. Food is any substance consumed to provide

nutritional support for the body. It is usually of plant or animal origin and contains essential nutrients, such

as carbohydrates, fats, proteins, vitamins and minerals.

Humans depend on

(i) Croplands

(ii) Range lands

(iii) Oceanic Fisheries

MAJOR FOOD RESOURCES

Our earth contains thousands of plants and animals.

Plant as Food Resources

Plants serve as food for Herbivores and Omnivores. Agriculture produces major food products

namely cereals, pulses, spices, beverages, fruits and vegetables.

Animal as Food Resources

Animals are the main sources of food for Carnivores and Omnivores. The meat of animal is

the food source for many organisms.

Effects of Under Nutrition

Visible effects - Low weight, unhealthy appearance.

Unseen effects - Muscles, Heart and Lungs can begin to deteriorate.

This can develop into fatigue, difficulty in breathing and when the body stops being able to

produce enough healthy blood cells, it can result in the development of anaemia.

Malnutrition

Malnutrition is the condition that occurs when human body does not get enough nutrients,

proteins, essential fats, vitamins, minerals and other nutrients.

Effects of Malnutrition

Protein deficiency - Weight loss, diarrhoea, stunted growth

Iron deficiency - Anaemia

Iodine deficiency - Goitre

Vitamin A deficiency - Blindness

2) Mineral resources.

A mineral is a naturally occurring homogeneous inorganic solid substance having a definite

chemical composition and characteristic crystalline structure, color and hardness.

Formation of mineral deposits

In particular spots the concentration of the mineral deposits are high, which can be extracted

profitably. The formation of these deposits is a very slow biological process, sometimes it may

take millions of years to develop as a mineral deposit.

Various biological processes

Mineral deposits are formed due to the biological decomposition of dead animals and

organic matters.

Mineral deposits are formed due to the concentration of minerals during cooling of molten

rock. (lava from volcano)

Mineral deposits are also formed due to the evaporation of sea water.

Mineral deposits are formed due to the concentration of minerals during weathering,

transport and sedimentation.

CLASSIFICATION OF MINERAL RESOURCES

Mineral deposits can be classified into three main groups:

Identified resources

Undiscovered resources

Reserve

USES OF MINERALS

Minerals provide important wealth to a country. The minerals are used for various purposes.

Industrial Use

Industries like Iron, Aluminum, Copper, Chromate are mainly depending on the mineral

resources.

These industries provide an IMPORTANT economy to our country.

Agricultural Use

Used as Fungicide and Pesticide.

Sulphur - Used for fungicides, sulphuric acid, explosives, kills bacteria, vulcanizes

rubber, used in coal and fuels and fertilizers.

Lubricants - Minerals are used as lubricants

Graphite - Used in pencils and as lubricants for machinery.

For Jewellery

Diamond - It is used in cutting tools, blades, saws and also beautiful gemstones

injewellery.

Gold - Used in dentistry and medicine, jewellery and arts.

Silver - Uses include photography, jewellery, electronics, as currency, alloys.

Pharmaceuticals

Minerals are used in pharmaceutical and in chemical industries for various purposes.

Example: Bismuth replaces toxic lead in many applications.

Storage Devices

Cadmium is used in plating and alloying, pigments, plastics and batteries.

Electrical Use

Garnet is used in water filtration, electronic components, ceramics, glass, jewellery and

abrasives used in wood furniture and transport manufacturing.

11. Explain in detail about the forest resources and give the merits and demerits of forest

resources. [M/J-2014]

Forest contributes significantly to the economic development of our country. Forests are

important renewable natural resources. Forests shape our natural environment by influencing

factors such as temperature, humidity and precipitation. Forests are the home for plants and

animals. They reduce pollution and prevent soil erosion.

The chief products which forests supply is wood which is used as fuel and raw materials, for

various industries such as pulp, paper, board, plywood, timber for furniture items. They also

produce minor forest products like cane, gum, resins, dyes, tannins, fish etc.

USES OF FORESTS

1. Forests provide main wealth of a country.

2. Forests provide valuable timber for domestic and commercial use.

3. Grazing of cattle in the forests helps in dairy farming and cattle rising.

4. Forests are the natural habitat for wild life and birds which attract tourists.

5. Forests offer employment to the people.

6. Forest plays an effective role in controlling humidity, temperature and precipitation.

7. Forests also help in controlling soil erosion, soil degradation and floods.

8. Forests maintain underground water table.

9. They increase the fertility of the soil.

10. Forests provide important medicinal plants.

11. Forests also provide abundant fuel.

12. Forests supply major and minor products required for industries.

13. Forest plays a major role in controlling the Global Warming. It reduces the greenhouse

gases. It maintains the level of carbon dioxide in the atmosphere and therefore checks

greenhouse effect.

Factors causing Over Exploitation

The factors which lead to overexploitation are

1. The demand for raw materials

2. Increase in population

3. Increasing civilization

4. Increase in Industrial Activities

5. Mining Activities

6. Farming

7. Forest Fires

8. River Projects

Effects of Over Exploitation

1. Loss in Biodiversity

2. Fall in economic level

12. Explain the role of an individual towards conservation of natural resources. [M/J-2014]

Conservation

- Conservation means using the resources in a wise manner to make our environment in a

healthy way for future generations.

Need for Conservation

- Use of natural resources is increasing but the amount of these resources gets decreased.

- Deforestation cause the loss of energy resources.

Objectives of conservation of natural resources

- To maintain the essential ecological processes i.e., food chain, recycling of mineral

resources etc. and the life support system – soil, air, water, pond, plants, animals etc.

- To ensure the availability and sustainability of resources which assumes the survival of all

species is in a healthy and easy manner.

Conservation of water

- Keeping the water taps closed, when not in use

- Watering the plants to be done in the evening

- Using drip irrigation and sprinkling irrigation

- Treated water from industries to be provided for irrigation purpose

- Water to be used carefully and economically

- Reuse the soapy water, after washing clothes to garden

- Built rainwater harvesting system in house

Conservation of energy

- Switch off lights, fans and other appliances when not in use.

- Use solar heater for cooking food on sunny days, which will cut down LPG expenses.

- Grow trees near the houses and get a cool breeze and shade .This will cut off electricity charges

on fans, A/C and coolers.

- Use always pressure cooker.

- Using alternative source of energy and developing the renewable sources of energy such as

solar energy, wind energy, tidal energy, nuclear energy, etc., for our energy requirements.

Conservation of soil

- Grow different types of plants, herbs, trees and grass in garden and open areas, which bind the

soil and prevent erosion.

- Don’t use more fertilizer and pesticides.

- Use natural manure to the crops.

- While constructing the house, don't uproot the trees as far as possible.

- Use mixed cropping, so that some specific soil nutrients will not get depleted.

- By conducting awareness programmes on afforestation.

- By making suitable outlet channels to carry out flood water.

Conservation of forest

- Use non-timber products

- Plant more trees and protect them

- Overgrazing must be controlled

- Minimize the use of papers and fuel wood

13. Describe the causes of deforestation. [N/D-2014]

.Deforestation is the destruction of forest resources due to natural and man – made activities.

Causes

1. Increase in demand of wood products

Forests are the valuable assets for our country. They provide habitat for plants and animals.

The people who need wood for their domestic purpose make deforestation.

2. Due to fuel requirements

To meet the fuel requirements, the rural people are cutting down the trees.

3. Due to developmental projects

The developmental projects across the various parts of the country also cause a major

change in the forest.

4. Due to mining operations Mining reduces the area forest.

5. Farming

Due to farming across various parts of our country, the cultivation of plants will differ and

also due to the demand, deforestation will take place.

6. Increase in Population

Due to the increase in population, forests are converted into rural areas which destroy the

living plants and animals.

7. Forest fires

Due to the increase in temperature, the forest fires will happen. This results in destroy of

plants and animals.

14. What is land degradation? Discuss the factors responsible for land degradation.

[N/D-2014]

LAND DEGRADATION OR SOIL DEGRADATION

Land degradation is the process of deterioration of soil or loss of fertility of soil.

Humans change clear land for agriculture and mining, urban and industrial development and

for timber.

1. Erosion

Erosion occurs when the topsoil gets blown or washed away. Soil erosion is natural or man-

made. Since topsoil takes so long to build back up through natural processes, erosion

damage is almost irreversible.

2. Acid Rain

Acid rain causes soil degradation. The contaminated water gets into forest soils and retards

tree and other plant growth. Acid rain comes from natural causes, like volcanoes, but a lot of it

also comes from man-made industry emissions.

3. Salinization

The accumulation of salts in overly irrigated soils, causing soil degradation in the form of

salinization. The presence of salts makes the plants to grow difficult in the soil.

4. Nutrient Loss

Deforestation and careless agricultural processes lead to soil degradation in the form of

nutrient loss. After soil becomes nutrient-poor, crops and naturally occurring plants have

a hard time growing in the area.

5. Water Erosion

The removal of particles by the wind due to the force of running water and heavy rainfall.

Causes of soil degradation

Over-grazing by animals

By Deforestation.

By Mining.

Natural causes such as running water, glaciers, wind etc.

Pollution by industries.

By Urbanization.

By Irrigation.

Increased use of Fertilizers and Pesticides.