Chapter 2

Contents
Chapter - 2

NATURAL RESOURCES AND THEIR CONSERVATION

© 2009 Jupiterimages Corporation

© 2009 Cengage Learning India Pvt. Ltd. All rights reserved

Contents

Natural Resources

Any substance that is obtained from nature and which can be transformed
into a form that becomes valuable and useful for human beings is termed as
a natural resource. Examples of natural resources are trees, crops, soil,
water, etc.

Natural resources can be classified on the basis of their origin as
biotic resources and abiotic resources, and on the basis of their continual
utility as renewable resources and non-renewable resources.


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Classification of Natural Resources

Renewable Resources

Resources whose continual harvest is possible with proper planning and
management, such as plants, animals, solar energy, wind energy, etc., are
known as renewable resources.

Non-renewable Resources

Those resources which once gone have very little chance of recovery or
resynthesis are called non-renewable resources. Examples of
non-renewable resources are coal, minerals, and petroleum.


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Forest Resources

A forest is a biotic community with a
predominance of trees; it is an important
renewable resource.

Forests restore oxygen in our
atmosphere through photosynthesis and
also provide solvents, medicines, fuels, and
many other products that are important for
our health and comfort.

India is rich in forest resources
with a great diversity of flora and fauna.


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Importance of Forests
Direct Benefits
•Forests provide timber for construction of buildings and furniture.

•They provide raw material for a number of large- and small-scale industries.

•They provide a variety of edible products for human beings and animals.

•They provide natural habitat to tribal people.

•They make manure and fuel wood available to humans.

•They are an important source of national income.

•They provide various medicinal plants.

•They increase the beauty of landscape and attract tourists.

•They are extremely helpful in generating employment opportunities.

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Indirect Benefits

•Forests help in minimizing natural hazards.

•They help in reducing soil erosion and siltation of downstream water bodies.

•They help in reducing desertification and land degradation.

•They help in maintaining biodiversity by providing habitat to wild animals.

•They help in regulating hydrological cycle.

•They help in regulating the gases in atmosphere.


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Deforestation
The term deforestation refers to the removal or reduction of forest cover.
Causes of Deforestation
•Encroachment of forest land for agricultural use

•Expansion of cities to accommodate the growing population

•Construction of dams, canals, and highways

•Establishment of industrial areas

•Demand for firewood

•Mining

•Shifting cultivation

•Submergence of forests in river valley projects

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Effects of Deforestation

•Loss of natural habitat of wild animals and plants
•Increased intensity and frequency of floods
•Land degradation
•Loss of forest products
•Change in climatic conditions
•Siltation of rivers and lakes
•Loss of revenue
•Change in hydrological cycle and reduced rainfall
•Increased socio-economic problem in the long run


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Control of Deforestation

•Mining activities should be prohibited in areas declared as protected
forests.

•Cutting of trees should be followed by massive plantation.

•The environmental laws and legal provisions should be strictly
enforced.

•Forest extension should be carried out through social forestry, agro
forestry, recreation forestry, extension forestry, etc.

•Public awareness should be created regarding medicinal and other
economic and environmental significance of forests.


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Water Resources

Importance of Water

•Water is the basic component of every living cell.

•It is the basic input required for agriculture.

•Hydel power can be used for generating hydroelectricity.

•It provides habitat to aquatic flora and fauna.

•Common salt can be obtained from water.


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Sources of Water

Ground Water

Water that is hidden underground in spaces between soil and rock particles
is known as ground water.

Surface Water

After precipitation, the amount of water that does not percolate
down into the ground or does not return to the atmosphere by
evaporation or transpiration and enters the rivers, streams, lakes,
ponds, wetland, or artificial reservoirs constitutes surface water.


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Effects of Over-utilization of Ground Water

•Reduced flow of surface water

•Lowering of water table

•Water logging

•Subsidence

•Degradation of water quality

•Increased salt content

•Increased power costs


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Dams: Benefits and Problems

Advantages of Dams

•Irrigation

•Production of electricity

•Promotion of navigation

•Recreation

•Control of floods

•Increase in the availability of water for domestic as well as

industrial purposes

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Disadvantages of Dams

•Deforestation and loss of biodiversity
•Sinking of agricultural and forest land
•Displacement of tribal people from their homes
•Unchecked growth of aquatic weeds
•Siltation of reservoirs due to degraded catchments conditions
•Change in microclimate
•Increase in water-borne and soil-borne diseases
•Increase in flash floods
•Increase in frequency of earthquakes
•Increase in water logging and salinity
•Changes in Earth's rotation
•Emission of greenhouse gases


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Mineral Resources
Minerals are naturally occurring chemical compounds, which are formed
under the crust of the Earth through inorganic processes.

Types of Minerals

•Metallic minerals (iron ore, lead, zinc, etc.)

•Non-metallic minerals (asbestos, dolomite, and gypsum)

•Fuel minerals (coal, petroleum, and natural gas)


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Environmental Effects of Extraction and Over-exploitation of
Mineral Resources
•Destruction of forest and damage to the earth’s surface

•Soil erosion and reduction in soil fertility

•Generation of large amount of wastes which degrade the quality of land

•Pollution of air, water, and land

•Lowering of water table leading to ground subsidence and ground water pollution

•Destruction of natural ecosystems and creation of trenches and open pits

•Earthquakes and other volcanic events

•Occupational health hazards to miners

•Emission of radioactive pollutants, ash and trace metals by the combustion of coal
and petroleum © 2009 Cengage Learning India Pvt. Ltd. All rights reserved

Contents

Food Resources
Natural or artificially produced materials, which are used as food to derive
metabolic energy, are called food resources.

Types of Food Resources

• Agricultural crops

• Livestock

• Fish


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World Food Problems

•Insufficient production

•Lack of irrigation facility

•Undernutrition and malnutrition

•Hoarding and black-marketing


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Factors causing Food Problems

•Geographical conditions

•Lack of rainfall

•Population growth

•Natural hazards

•Inadequate distribution system

•Poor quality of soil

•Social disruption and terrorism


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Water-Logging and Salinity

Accumulation of water on land for longer period is known as water-
logging.

Water logging causes moisture to percolate down, which dissolves
the underground salts in it; these salts emerge on the surface of land after
the water is evaporated. This leads to salinity in soils.

Regions enriched with canals and dams for irrigation are more
prone to water logging which increases the accumulation of salt in the
water-logged areas.


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Effects of Water-Logging

•Water-logging accelerates denitrification, which leads to loss of
nitrogen.

•There is a lack of oxygen in water-logged areas.

•Because of the deficiency of nitrogen and oxygen, water-logged areas
support the growth of only certain specific plant species.

•Water-logged areas support the growth of unwanted microorganisms
causing rapid decomposition of accumulated organic matter. This
creates a foul odour.

•Long term water-logging reduces the aesthetic value of the region.


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Effects of Chemical Fertilizers

• Chemical fertilizers cause loss of soil fertility and degradation
of soil quality.

• They create nitrate pollution in groundwater when they dissolve
in water and seep into the soil.

• Excess fertilizer from agricultural fields finds its way into
ponds, lakes and rivers through run-off from water from the
fields. These run-off fertilizers speed up the growth of algae in
the pond, lake and river waters. This phenomenon is known as
eutrophication.

• The nitrogen fertilizers lead to the accumulation of nitrate in the
soil which are transformed to living organisms.

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Effects of Chemical Pesticides

• Most pesticides are not very specific and kill many non-target organisms as well.

• Pesticides adversely affect harmless species such as frogs, snakes, and birds, which are
natural pest-control mechanisms.

• There is an increase in the resistance to pesticides in insects, pathogens, weeds, etc.,
because of indiscriminate use.

• Pesticides from agricultural lands run down with rain water and enter local streams or
lakes.

• Pesticides adversely affect the health of farmers.

• Pesticides are retained in soil, and get concentrated in crops, vegetables, cereals, and
fruits leading to bio-magnification; the magnified levels of toxins then enter the
human body and cause serious damage.

• Excessive use of pesticides causes air, water, and soil pollution.


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Overgrazing
The term overgrazing refers to the practice of grazing by a large livestock for
a long period on a land without giving sufficient recovery time.

Effects of Overgrazing

• Elimination of sensitive palatable plant species and dominance of
spiny, non-palatable, and alien species.
• Acceleration of soil erosion and decrease in soil fertility.
• Accumulation of large quantity of animal wastes in downstream
water bodies causing problems of water pollution and
eutrophication.
• Grazing animals sometimes bring seeds of weeds and pathogenic
organisms which may often become harmful to other animals.
• Increase in reflectivity of land surfaces, which in turn, lowers
surface temperature and reduce the quantity of rain and thereby
increasing the chances of drought.


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Environmental Effects of Modern Agriculture

•Soil erosion and loss of fertility
•Sedimentation
•Change in land use patterns
•Fertilizer problems
•Pesticide problems
•Irrigation related problems
•Problems due to agriculture animals
•Climate change
•Effect on biogeochemical cycles
•Loss of genetic diversity
•Intensification of inequity


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Energy Resources

Renewable Energy Sources

Renewable sources of energy or flow sources, rely on natural energy
flows and sources in the environment and thus have the potential of being
continually replenished. These include firewood, petroplants, animal dung,
solar energy, wind energy, geothermal energy, tidal energy, etc.

Non-renewable Energy Sources

Non-renewable energy sources are available in limited amount and
develop over a longer period. Because of indiscriminate use they are
likely to be exhausted in the near future. These include coal, mineral
oil, natural gas, nuclear power, etc.


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Renewable Sources of Energy

•Solar Energy

•Wind Energy

•Tidal Energy

•Geothermal Energy

•Biomass Based Energy


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Non-Renewable Sources of Energy

•Coal

•Natural gas and oil

•Nuclear energy


Contents
Land Resources

The Importance of Land

• The human civilization has thrived on land.

• Land is used for agriculture.

• Land contains huge amount of mineral deposits.

• It also contains water in the form of underground water.

• Most of the animals find their habitat on land.

• Land directly or indirectly provides all the resources required to fulfil the
basic needs of humans: food, cloth, and shelter.


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Land Degradation
Lowering of the quality of land is commonly referred to as land degradation.

Causes of Land Degradation
•Mining

•Urbanization

•Deforestation

•Overgrazing

•Construction of dams and canals

•Excessive use of fertilizers

•Dumping of industrial and domestic waste

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Soil Erosion

The detachment and transportation of the fertile layer of soil by water or air.

Causes of Soil Erosion

•Large-scale deforestation for meeting commercial as well as day-to-day needs

•Heavy floods in rivers

•Overgrazing by cattle

•Dry violent winds

•Improper agricultural techniques


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Effects of Soil Erosion

•Decrease in productivity of land

•Desertification of land

•Reduction in the agricultural land at the banks of rivers

•Deposition of soil in river beds and canals causing diversion of

their natural flow and hence leading to disasters


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Methods of Controlling Soil Erosion
•Reduced tillage

•Contour bunding

•Vegetative bunds

•Strip cropping

•Terracing

•Afforestation on barren land

•Control of overgrazing

•Construction of small check dams

•Promotion of equitable use of water resources

•Prevention of excavation of rocks

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Desertification

Conversion of fertile land into an infertile desert land is called desertification.

Causes of Desertification

Natural Factors Anthropogenic Factors

•Very low rainfall •Continuous cutting of trees

•Excessive evaporation •Overgrazing

•Vast difference in diurnal temperature •Over irrigation
extremes
•Excessive ploughing
•High salinity of soils
•Conversion of pastures to arable lands

•Excessive use of fertilizers

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Effects of Desertification

•Rapid soil erosion

•Poor soil quality

•Unfavorable climate

•Low water table, salty and hard water

•Huge economic losses


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Control of Desertification

•Promoting large-scale plantation of trees

•Changing agricultural practices and promoting dry land farming

•Development of pasture lands and control of overgrazing

•Promoting equitable use of water resources

•Development of water catchment areas


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Role of an Individual in Conservation of Natural Resources
•Energy Conservation
Switch off electric lights and appliances whenever not needed
Ride a bicycle as often as possible

•Forest Conservation
Plant a large number of trees
Make equitable use of forest and forest products

•Water Conservation
Repair leakages
Save water in agriculture and domestic activities
Adopt rainwater harvesting techniques

•Land Conservation
Do not dump agricultural, industrial, and domestic waste on land

•Sustainable Food
Adopt vegetarian food habits
.
Use unpackaged food items such as vegetables and dry beans instead of canned or
packaged food

Contents


Chapter 2

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