1585913834_UNIT_32.pdf

Dr. Kumar Anandam Page 1
UNIT 3.2: WATER RESOURCES
Water: Use and over-exploitation of surface and ground water,
floods, droughts, conflicts over water (international & inter-
state).
WATER RESOURCES:
Water is the most abundant, inexhaustible renewable resource. It covers 70% of the globe
in the form of oceans, rivers, lakes, etc. Of this 70%, only 3% is available as freshwater.
From this 3%, roughly 2% is frozen in polar icecaps and only a fraction of the remaining
1% is used as drinking water (potable). 90% of the water is utilized for agricultural
purposes in India.
USE OF SURFACE AND GROUND WATER
Consumptive use: In such uses, water is completely utilized and cannot be reused. Ex:
Domestic, industrial and irrigation
Non-consumptive use: In such uses, water is not completely utilized and is reused Ex:
Hydropower plant
Other uses:
1. Water is used for domestic purposes like drinking, bathing, cooking, washing. etc.
2. Water is used in commercial establishments like hotels, theaters, educational
institutions, offices, etc.
3. Almost 60-70% of fresh water is used for irrigation
4. 20-30% of water is used for industrial operations by refineries, iron & steel industries,
paper & pulp industries, etc.
5. Water plays a key role in sculpting the earths surface, moderating climate and diluting
pollutants.
OVER-UTILIZATION OF SURFACE & GROUND WATER
The rapid increase in population and industrial growth led to severe demand on water
resources. After using all available surface water resources to the maximum, human
beings began using groundwater to meet their needs.
1. The increased extraction of groundwater far in excess of the natural recharge led to
decreased groundwater level. The erratic and inadequate rainfall caused reduction in
storage of water in reservoirs. This also led to decrease of groundwater.

2. Building construction activities seal permeable soil zone and reduce the area for
percolation of rainwater thereby increasing surface runoff.
3. If groundwater withdrawal rate is higher than recharge rate, sediments in aquifers get
compacted resulting in sinking of overlaying land surface. This is called land subsidence
which leads to structural damage in buildings, fracture in pipes and reverses the flow of
canals leading to tidal flooding.
4. Over-utilization of groundwater in arid and semi-arid regions for agriculture disturbs
equilibrium of reservoir in the region causing problems like lowering of water table and
decreased pressure in aquifers coupled with changes in speed and direction of water flow.
5. Over utilization of groundwater in coastal areas leads to rapid intrusion of salt water
from the sea thereby rendering it unusable for drinking and agriculture.
6. Over-utilization of groundwater lads to decrease in water level thereby causing
earthquake, landslides and famine.
7. Over-utilization of groundwater leads to drying-up of dug wells as well as bore wells.
8. Due to excess use of groundwater near agricultural fields, agricultural water that
contains nitrogen as a fertilizer percolates rapidly and pollutes the groundwater thereby
rendering the water unfit for potable use by infants. (Nitrate concentration exceeding 45
mg/L).
Drought
Water is a very basic necessity for the survival of life on earth. Imagine life with
insufficient amount of water, it will be impossible to do the daily activities of cleaning,
cooking, drinking etc. Life will turn out to be a miserable chaos. Water cycle has helped
in maintaining the quantity of water on the surface of earth. About 50 liters of water is
needed per day per person in order to sustain a healthy life. There are many areas where
people do not receive this basic quantity of water. Areas that do not receive adequate
amount of rainfall and have dry soil suffer from droughts. Whereas areas which receive
heavy rainfall and have marshy soil generally get flooded. Floods and droughts are
contrary concepts. Droughts occur when a long period of abnormally dry weather leads to
a severe water shortage. Droughts are also often caused by the activity of humans and can
have devastating effects. Drought conditions result from a lack of precipitation and this
has many effects on the surrounding land and weather conditions. Drought conditions can
worsen after prolonged periods of no rainfall, especially in areas where the water supply
is short.
What causes drought?
Lack of rainfall (or precipitation):
Droughts can occur when there is the lack of ‘expected’ precipitation (rain and snow).
Note that we say ‘expected’ because the lack of rain alone does not mean a drought.

Some regions can go for months without any rain, and that would be ‘normal’ for them.
Farmers plant in anticipation of rains and so when the rains do not come, and irrigation
infrastructure is absent, agricultural drought occur.
Surface water flow: Some regions are also well distributed with surface water (streams
and rivers) that have their sources from far away mountains and watersheds. These
surface waters may dry out if the flow from their sources upstream is affected. Hydro-
electric dams and irrigation systems are some of the economic activities that can reduce
the amount of water flowing to other areas downstream.
Human factors: Forests (trees) play a key role in the water cycle, as they help reduce
evaporation, store water and also contribute to atmospheric moisture in the form of
transpiration. This means, cutting down trees (deforestation) in the name of economics,
will expose surface water to more evaporation. It will also reduce the ability of the
ground to hold water and make it easier for desertification to occur. It can set off drying
conditions, especially for smaller water bodies. Cutting down trees is known to reduce a
forest’s watershed potential.
Global Warming: Even though some people do not accept that the average temperature
of the earth has risen, it is on record that human actions have contributed to more
greenhouse gasses in the atmosphere. As a result, there are warmer temperatures, often
resulting in more dryness and bush fires. These conditions also tend to speed up drought
conditions.
Effects of Drought
Economic:
Farmers will have to spend more money to irrigate the crops and provide water for
livestock on animal farms and ranches. They have to spend money to drill new wells or
buy water in tankers from far away places.
Environment: Drought also affects the environment in many different ways. Plants and
animals depend on water, just like people. When a drought occurs, their food supply can
shrink and their habitat can be damaged. Plants, animals, climate, soils, rocks and many
others are all affected by drought conditions. Some biotic and abiotic factors recover
when the droughts are over. Others never recover again.
People and animals: Hunger, malnutrition, anaemia and mortality impacts of droughts
are indirect in nature. Droughts cause low food production (crops and livestock), and
particularly in poorer regions, people have less to eat. Food nutrition also is a problem,

and that leads to vulnerability, diseases/illness and deaths. This is particularly so in
remote communities of poorer countries, where communication and accessibility is
usually poor. Other Effects:
1. Dust bowls, themselves a sign of erosion, which further erode the landscape.
2. Dust storms, when drought hits an area suffering from desertification and erosion.
3. Famine due to lack of water for irrigation.
4. Habitat damage, affecting both terrestrial and aquatic wildlife
5. Hunger, drought provides too little water to support food crops.
6. Malnutrition, dehydration and related diseases.
7. Mass migration, resulting in internal displacement and international refugees.
8. Social unrest.
9. War over natural resources, including water and food.
10. Wildfires are more common during times of drought and even death of people.
Prevention of Drought
1. Dams – many dams and their associated reservoirs supply additional water in times of
drought.
2. Cloud seeding – a form of intentional weather modification to induce rainfall. This
remains a hotly debated topic, as the United States National Research Council released a
report in 2004 stating that to date, there is still no convincing scientific proof of the
efficacy of intentional weather modification.
3. Desalination – of sea water for irrigation or consumption.
4. Drought monitoring – Continuous observation of rainfall levels and comparisons with
current usage levels can help prevent man-made drought. Careful monitoring of moisture
levels can also help predict increased risk for wildfires, using such metrics as the Keetch-
Byram Drought Index or Palmer Drought Index.

5. Land use – Carefully planned crop rotation can help to minimize erosion and allow
farmers to plant less water-dependent crops in drier years.
6. Outdoor water-use restriction – Regulating the use of sprinklers, hoses or buckets on
outdoor plants, filling pools, and other water-intensive home maintenance tasks.
Xeriscaping yards can significantly reduce unnecessary water use by residents of towns
and cities.
7. Rainwater harvesting – Collection and storage of rainwater from roofs or other
suitable catchments.
8. Recycled water – Former wastewater (sewage) that has been treated and purified for
reuse.
FLOOD
What is flooding: Flooding is an overflowing of water onto land that is normally dry.
Floods can happen during heavy rains, when ocean waves come on shore, when snow
melts too fast, or when dams or levees break. Flooding may happen with only a few
inches of water, or it may cover a house to the rooftop. They can occur quickly or over a
long period and may last days, weeks, or longer. Floods are the most common and
widespread of all weather-related natural disasters. Flash floods are the most dangerous
kind of floods, because they combine the destructive power of a flood with incredible
speed and unpredictability. Flash floods occur when excessive water fills normally dry
creeks or river beds along with currently flowing creeks and rivers, causing rapid rises of
water in a short amount of time. They can happen with little or no warning.
Reasons of Flood
Rains: Each time there are more rains than the drainage system can take, there can be
floods. Sometimes, there is heavy rain for a very short period that result in floods. In
other times, there may be light rain for many days and weeks and can also result in
floods.
River overflow: Rivers can overflow their banks to cause flooding. This happens when
there is more water upstream than usual, and as it flows downstream to the adjacent low-
lying areas (also called a floodplain), there is a burst and water gets into the land.
Strong winds in coastal areas: Sea water can be carried by massive winds and
hurricanes onto dry coastal lands and cause flooding. Sometimes this is made worse if the
winds carry rains them. Sometimes water from the sea resulting from a tsunami can flow
inland to cause damage.

Dam breaking (Dmas are built along the side of a river and are used to prevent high
water from flooding bordering land). Sometimes, too much water held up in the dam can
cause it to break and overflow the area. Excess water can also be intentionally released
from the dam to prevent it from breaking and that can also cause floods.
Snow-melts: In many cold regions, heavy snow over the winter usually stays un-melted
for sometime. There are also mountains that have ice on top of them. Sometimes the ice
suddenly melts when the temperature rises, resulting in massive movement of water into
places that are usually dry. This is usually called a snowmelt flood. A flood occurs when
water overflows or inundates land that's normally dry. This can happen in a multitude of
ways. Most common is when rivers or streams overflow their banks. ... Coastal flooding
occurs when a large storm or tsunami causes the sea to surge inland.
Effects of Floods
Floods can have devastating consequences and can have effects on the economy,
environment and people. During floods (especially flash floods), roads, bridges, farms,
houses and automobiles are destroyed. People become homeless. Floods can have
devastating consequences and can have effects on the economy, environment and people.
Economic: During floods (especially flash floods), roads, bridges, farms, houses and
automobiles are destroyed. People become homeless. Additionally, the government
deploys firemen, police and other emergency apparatuses to help the affected. All these
come at a heavy cost to people and the government. It usually takes years for affected
communities to be re-built and business to come back to normalcy.
Environment: The environment also suffers when floods happen. Chemicals and other
hazardous substances end up in the water and eventually contaminate the water bodies
that floods end up in. In 2011, a huge tsunami hit Japan, and sea water flooded a part of
the coastline. The flooding caused massive leakage in nuclear plants and has since caused
high radiation in that area. Authorities in Japan fear that Fukushima radiation levels are
18 times higher than even thought.
People and animals: Many people and animals have died in flash floods. Many more are
injured and others made homeless. Water supply and electricity are disrupted and people
struggle and suffer as a result. In addition to this, flooding brings a lot of diseases and
infections including military fever, pneumonic plague, dermatopathia and dysentery.
Sometimes insects and snakes make their ways to the area and cause a lot of havoc.

Prevention of Flood
Humans cannot stop the rains from falling or stop flowing surface water from bursting its
banks. These are natural events, but we can do something to prevent them from having
great impact. Here are a few. Sea walls and tide gates have been built in some places to
prevent tidal waves from pushing the waters up ashore. In some areas too, sand bags are
made and placed in strategic areas to retain floodwaters.
Retaining walls: In some places, retaining walls levees, lakes, dams, reservoirs or
retention ponds have been constructed to hold extra water during times of flooding.
Town planning: It is important that builders acquire permission before buildings are
erected. This will ensure that waterways are not blocked. Also, drainage systems must be
covered and kept free from objects that chock them. This way, water can quickly run
through if it rains and minimize any chance of town flooding. Drainage systems should
also be covered to prevent litter from getting into them.
Vegetation: Trees, shrubs and grass help protect the land from erosion by moving water.
People in low-lying areas must be encouraged to use a lot of vegetation to help break the
power of moving flood water and also help reduce erosion.
Education: In many developing countries, drainage systems are chocked with litter and
people have little knowledge of the effects that can have during a rain. Education is
therefore very important, to inform and caution people about the dangers of floods, what
causes floods, and what can be done to minimise its impact.
Conflicts over water (international & inter-state).
Conflict through pollution: Rivers are also used for industrial purposes. They act as
reservoirs for supply of fresh water and also a receptor of waste water and rubbish from
the industry. Water crossing borders that has been polluted by wastes from one country
develops into an international conflict.
Management of water conflicts
1. Concerted efforts are required to enforce laws that check these practices to control
water pollution
2. In order to overcome the problem of sharing river water in a country, the concept of
interlinking of rivers has been suggested
3. Rivers should be nationalized, the National Water Authority and River Basin Authority
should be given powers to ensure equitable distribution of basin water

Food resources:
World food problems, changes caused by agriculture and overgrazing,
effects of modern agriculture, fertilizer-pesticide problems, water
logging, salinity, case studies.
Food Resources:
Today our food comes almost entirely from agriculture, animal husbandry and fishing.
Although India is self-sufficient in food production, it is only because of modern patterns
of agriculture that are unsustainable and which pollute our environment with excessive
use of fertilizers and pesticides. The FAO defines sustainable agriculture as that which
conserves land, water and plant and animal genetic resources, does not degrade the
environment and is economically viable and socially acceptable. Most of our large farms
grow single crops (monoculture). If this crop is hit by a pest, the entire crop can be
devastated, leaving the farmer with no income during the year. On the other hand, if the
farmer uses traditional varieties and grows several different crops, the chance of complete
failure is lowered considerably. Many studies have shown that one can use alternatives to
inorganic fertilizers and pesticides. This is known as Integrated Crop Management.
World food problems:
In many developing countries where populations are expanding rapidly, the production
of food is unable to keep pace with the growing demand. Food production in 64 of the
105 developing countries is lagging behind their population growth levels. These
countries are unable to produce more food, or do not have the financial means to import
it. India is one of the countries that have been able to produce enough food by cultivating
a large proportion of its arable land through irrigation. The Green Revolution of the 60’s
reduced starvation in the country. However many of the technologies we have used to
achieve this are now being questioned.
• Our fertile soils are being exploited faster than they can recuperate.
• Forests, grasslands and wetlands have been converted to agricultural use, which has led
to serious ecological questions.
• Our fish resources, both marine and inland, show evidence of exhaustion.
• There are great disparities in the availability of nutritious food.
Some communities such as tribal people still face serious food problems leading to
malnutrition especially among women and children. These issues bring in new questions
as to how demands will be met in future even with a slowing of population growth.

Today the world is seeing a changing trend in dietary habits. As living standards are
improving, people are eating more non-vegetarian food. As people change from eating
grain to meat, the world’s demand for feed for livestock based on agriculture increases as
well. This uses more land per unit of food produced and the result is that the world’s poor
do not get enough to eat. Women play an extremely vital role in food production as well
as cooking the meal and feeding children. In most rural communities they have the least
exposure to technical training and to health workers trained in teaching/learning on issues
related to nutritional aspects. Women and girls frequently receive less food than the men.
These disparities need to be corrected. Poor environmental agricultural practices such as
slash and burn, shifting cultivation, or ‘rab’ (woodash) cultivation degrade forests.
Globally 5 to 7 million hectares of farmland is degraded each year. Loss of nutrients and
overuse of agricultural chemicals are major factors in land degradation. Water scarcity is
an important aspect of poor agricultural outputs. Salinization and water logging has
affected a large amount of agricultural land worldwide. Loss of genetic diversity in crop
plants is another issue that is leading to a fall in agricultural produce. Rice, wheat and
corn are the staple foods of two thirds of the world’s people. As wild relatives of crop
plants in the world’s grasslands, wetlands and other natural habitats are being lost, the
ability to enhance traits that are resistant to diseases, salinity, etc. is lost. Genetic
engineering is an untried and risky alternative to traditional cross breeding.
Food security, loss of genetic diversity and alternate food sources
(fisheries): Please refer page 33 and 34 from Environmental studies (by Erach
Bharucha)
Changes caused by agriculture and overgrazing:
Agriculture is the world’s oldest and largest industry; more than half of all the people in
the world still live on farms. But, because of production, processing and distribution of
food — and that took on a large scale larger effects on the environment are unavoidable.
Agriculture has both primary and secondary environmental effects. A primary effect is an
effect on the area where the agriculture takes place i.e. on-site effect. A secondary effect,
also called an off-site effect, is an effect on an environment away from the agricultural
site. The effects of agriculture on the environment can be broadly classified into three
groups, viz. global, regional and local:
(1) Global Effects: These include climate changes as well as potentially extensive
changes in chemical cycles.
(2) Regional Effects: These generally result from the combined effects of farming
practices in the same large region. Regional effects include deforestation, desertification,
large scale pollution, increase in sedimentation in major rivers and in the estuaries at the

mouths of the rivers and changes in the chemical fertility of soils over large areas. In
tropical waters, sediments entering the ocean can destroy coral reefs.
(3) Local Effects: These occur at or near the site of farming. These changes / effects
include soil erosion and increase in sedimentation downstream in local rivers. Fertilizers
carried by sediments can also transport toxins and destroy local fisheries.
Changes caused by Overgrazing:
The carrying capacity of land for cattle depends on the fertility of the soil and the rainfall.
When the carrying capacity is exceeded, the land is overgrazed. The changes that result
from overgrazing include: (a) Reduction in the growth of vegetation. (b) Reduction in the
diversity of plant species. (c) Increased soil erosion as the plant cover is reduced. (d)
Damage from the cattle trampling on the land, like paths made by cattle develop into
gullies, which erode rapidly in the rain. (e) Dominance of plant species that are relatively
undesirable to the cattle.
Effects of modern agriculture - Fertilizer Pesticide problems,
Water logging, Salinity
AGRICULTURE
Agriculture is an art, science and industry of managing the growth of plants and animals
for human use. Agriculture includes preparation of soil for cultivation of crops,
harvesting crops, breeding and raising livestock, dairying and forestry. The two major
types of agriculture are:
1. Traditional agriculture
2. Modern or Industrialized agriculture
MODERN AGRICULTURE
Modern agriculture makes use of hybrid seeds of single crop variety, technologically
advanced equipment, fertilizers, pesticides and water to produce large amounts of
single crop.
Problems using fertilizers
1. Micronutrient imbalance: Chemical fertilizers used in modern agriculture contain
Nitrogen, Phosphorus and Potassium (N,P,K) which are macronutrients. Excess use
of fertilizers in fields causes micronutrient imbalance. Ex: Excessive use of fertilizers
in Punjab and Haryana caused deficiency of micronutrient Zinc thereby affecting
productivity of soil.

2. Nitrate pollution: Excess Nitrogenous fertilizers applied in fields leach deep into
the soil contaminating the groundwater. If the concentration of nitrate in drinking
water exceeds 25 mg/L it leads to a fatal condition in new-born babies. This condition
is termed "Blue Baby Syndrome"
3. Eutrophication: The application of excess fertilizers in fields leads to wash off of
the nutrient loaded water into nearby lakes causing over-nourishment. This is called
"Eutrophication". Eutrophication causes the lakes to be attacked by "algal blooms".
Algal blooms use nutrients rapidly and grow fast. Their life is short, they die and
pollute water thereby affecting aquatic life in the lake.
Problems in using Pesticides: In order to improve crop yield, pesticides are used
indiscriminately in agriculture. Pesticides are of two types:
1. First generation pesticides that use Sulphur, Arsenic, Lead or Mercury to kill pests
2. Second generation pesticides such as Dichloro Diphenyl Trichloroethane (DDT)
used to kill pests. These pesticides are organic in nature.
Although these pesticides protect our crops from severe losses due to pests, they have several
side-effects as listed below:
1. Death of non-target organisms: Several insecticides kill not only the target
species but also several beneficial not target organisms
2. Pesticide resistance: Some pests that survive the pesticide generate highly
resistant generations that are immune to all kinds of pesticides. These pests are
called "superpests"
3. Bio-magnification: Most pesticides are non-biodegradable and accumulis ate in
the food chain. This is called bio-accumulation or biomagnification. These
pesticides in a bio-magnified form are harmful to human beings.
4. Risk of cancer: Pesticide enhances the risk of cancer in two ways
(i) It acts as a carcinogen
(ii) It indirectly suppresses the immune system.
WATER LOGGING
If water stands on land for most of the year, it is called water logging. In water logged
conditions, pore-voids in the soil get filled with water and soil-air gets depleted. In such a
condition the roots of plants do not get enough air for respiration. Water logging also leads to
low mechanical strength of soil and low crop yield.

CAUSES OF WATER LOGGING
1. Excessive water supply to the croplands
2. Heavy rain
3. Poor drainage
MEASURES TO PREVENT WATER LOGGING
1. Avoid and prevent excessive irrigation
2. Sub-surface drainage technology
3. Bio-drainage by trees like Eucalyptus
SALINITY
Water not absorbed by soil, is evaporated leaving behind a thin layer of dissolved salts in the top
soil. This is called salinity of the soil. Saline soils are characterized by accumulation of soluble
salts like sodium chloride, calcium chloride, magnesium chloride, sodium sulphate, sodium
carbonate and sodium bicarbonates. Saline conditions are exhibited when pH is greater than 8.0
PROBLEMS IN SALINITY
Saline soils yield less crop In order to remedy the condition of saline soils the following two
techniques may be used:
1. Salt deposit is removed by flushing with good quality water
2. By using a sub-surface drainage system, the salt water is flushed out slowly.
CASE STUDIES
Canal irrigation in Haryana resulted in rising water table followed by water logging and salinity
causing low crop productivity thereby huge economic losses. Similarly the "Indira Gandhi Canal
Project" in Rajasthan converted a big area into a "water soaked waste land". In Delhi,
accumulation of pesticides and DDT in the body of mothers caused premature deliveries or low
birth weight infants. Food centre at Center for Science and Environment (CSE) India reported
Pepsi and Coca-Cola companies sold soft drinks with a pesticide content 30-40 times higher than
EU guidelines permit. At the reported concentrations the pesticides damage the nervous system.
Israel began using drip irrigation (Drip irrigation is a type of micro-irrigation that has the
potential to save water and nutrients by allowing water to drip slowly to the roots of plants, either
from above the soil surface or buried below the surface) systems as it is short of water. With this
technique, farmers have been able to improve the efficiency of irrigation by 95%. Over a 20-year
period, Israel’s food production doubled without an increase in the use of water for agriculture.
In India, some traditional communities in urban and semi urban towns used to grow their own

vegetables in backyards on wastewater from their own homes. Calcutta releases its waste water
into surrounding lagoons in which fish are reared and the water is used for growing vegetables.
Energy resources:
Renewable and non-renewable energy sources, use of alternate
energy sources, growing energy needs, case studies.
Renewable and non-renewable energy sources
Energy is broadly classified into two main groups: Renewable and Non-renewable.
Renewable Energy
Renewable energy is the energy which is generated from natural sources i.e. sun, wind, rain,
tides and can be generated again and again as and when required. They are available in plenty
and by far most the cleanest sources of energy available on this planet. For e.g.: energy that we
receive from the sun can be used to generate electricity. Similarly, energy from wind,
geothermal, biomass from plants, tides can be used to fulfill our daily energy demands.
Pros and Cons of Renewable energy:
• The sun, wind, geothermal, ocean energy are available in the abundant quantity and free to use.
• The non-renewable sources of energy that we are using are limited and are bound to expire one
day.
• Renewable sources have low carbon emissions, therefore they are considered as green and
environment friendly.
• Renewable helps in stimulating the economy and creating job opportunities. The money that is
used to build these plants can provide jobs to thousands to millions of people.
• You don’t have to rely on any third country for the supply of renewable sources as in case of
nonrenewable sources.
• Renewable sources can cost less than consuming the local electrical supply. In the long run, the
prices of electricity are expected to soar since they are based on the prices of crude oil, so
renewable sources can cut your electricity bills.
• Various tax incentives in the form of tax waivers, credit deductions are available for individuals
and businesses who want to go green. Cons
• It is not easy to set up a plant as the initial costs are quite steep.
• Solar energy can be used during the day time and not during night or rainy season.

 Geothermal energy which can be used to generate electricity has side effects too. It can
bring toxic chemicals beneath the earth surface onto the top and can create environmental
changes.
 Hydroelectric provide pure form of energy but building dams across the river which is
quite expensive can affect natural flow and affect wildlife.
 To use wind energy, you have to rely on strong winds therefore you have to choose
suitable site to operate them.
Non-Renewable Energy
Non-Renewable energy is the energy which is taken from the sources that are available on
the earth in limited quantity and will vanish fifty-sixty years from now. Non-renewable
sources are not environmental friendly and can have serious affect on our health. They are
called nonrenewable because they cannot be re-generated within a short span of time. Non-
renewable sources exist in the form of fossil fuels, natural gas, oil and coal. Here are some of
the pros and cons of using non-renewable sources of energy:-
Pros and Cons of non-renewable energy;
Non-renewable sources are cheap and easy to use. You can easily fill up your car tank and
power your motor vehicle. You can use small amount of nuclear energy to produce large
amount of power. Non-renewable have little or no competition at all. For eg: if you are
driving a battery driven car your battery gets discharged then you won’t be able to charge it
in the middle if the road rather it is easy to find a gas pumping station. They are considered
as cheap when converting from one type of energy to another. Non-renewable sources will
expire some day and we have to us our endangered resources to create more non-renewable
sources of energy. The speed at which such resources are being utilized can have serious
environmental changes. Non-renewable sources release toxic gases in the air when burnt
which are the major cause for global warming. Since these sources are going to expire soon,
prices of these sources are soaring day by day.
Why Should We Conserve Energy?
Energy needs to be conserved to protect our environment from drastic changes, to save the
depleting resources for our future generations. The rate at which the energy is being
produced and consumed can damage our world in many ways. In other words, it helps us to
save the environment. We can reduce those impacts by consuming less energy. The cost of
energy is rising every year. It is important for us to realize how energy is useful to us and
how can we avoid it getting wasted. Home energy auditors will develop custom solutions to
keep the energy efficiency of your home at its highest level. To start saving energy is not a
big thing at all. We can start saving the energy from our home itself, just by turning off the
lights during day hours, washing clothes in cold water or using public transport instead of
using our own vehicle and later can implement these things on much wider scale at society

level, then at city level then district level and finally at country level. Alternate Renewable
Energy Sources
USE OF ALTERNATE RENEWABLE ENERGY SOURCES
Human civilization has started realizing how much harm they have already caused to the
environment; and when it comes to take a stand against these environmental problems, the
focus shifts to the use of alternative energy sources. Have you ever wondered what
Alternative Energy Sources are? and why are they supposed to help us sustain? Alternative
sources of energy are the ones which do not cause any undesirable consequences to the
environment, are renewable and are free! Alternative energy sources can be implemented for
houses, for cars, factories and any other facility you can imagine. Scientists around the world
are researching on developing and discovering new Alternative Energy Sources so that the
growing energy needs of human population can be met more easily, safely and efficiently.
Here is a list of Alternative Energy Sources which will help us maintain the balance of nature
without causing it much harm as compared to the conventional energy sources.
1. Solar energy is renewable and does not cause environmental pollution
2. Energy sources that create minimum pollution, are safe not prone to security threats and
have universal availability have the best chance of large scale utilization in future.
3. Hydro-electric power generation is expected to the existing ecological balance
4. Apart from generating heat, hydel power plants critically endanger aquatic and terrestrial
biotic
5. Radioactive pollutants released from nuclear plants are chronically hazardous.
Commissioning of Boiling Water Power Reactors (BWRs) result in accumulation of large
number of radionuclides in water
6. Dangerous radioactive waste cannot be buried in/land without the risk of polluting soil and
underground water. The waste cannot be dumped in rivers as it poisons aquatic life and
human beings.
7. Burning of coal, oil, wood, dung cakes and petroleum products have well established
environmental problems. The smoke produced causes respiratory and digestive problems
leading to lung, stomach and eye diseases.
8. Disposal of fly-ash requires large ash ponds and may pose a severe problem considering
the limited availability of land. Hence non-conventional sources of energy are needed. The
objectives of using alternate renewable energy sources are listed below:
1. To provide more energy to meet the requirements of increasing population.
2. To reduce environmental pollution and
3. To reduce safety and security risks associated with the use of nuclear energy.

CASE STUDIES
Wind energy India is generating 1200 MW electricity using wind energy. The largest wind
farm is in Kanyakumari in Tamil Nadu, which generates 380 MW electricity. Hydrogen-Fuel
cell car General motor company of china invented experimental cars that run on electric
motors fueled by hydrogen and oxygen. These cars produce no emission and the only waste
products being water droplets and water vapour. Commonly known alternative energy
sources
Hydroelectric Energy The potential energy stored in the water held in dams by is made to
drive a water turbine and generator which in turn produces electric power. This form of
energy generation is called hydroelectric power. Out of all the alternative energy sources, this
one has been most commonly adopted in the current time. Advantages of hydroelectric power
generation – The source of hydroelectric power generation i.e., water is free of cost. – Dams
can provide virtually continuous electricity generation. – The water used for power
generation can be put to use again. – There is no chemical process involved in the power
production process, therefore, the power generated is clean and does not harm the
environment.
Solar Energy (Also refer text book erach Bharucha, Page 43-45) This is the energy which
the earth receives from the Sun. This is one of the most promising alternative energy sources,
which will be available to the mankind for centuries to come. The only challenge remains to
tap the solar energy in the most efficient way. The solar power generation is done by using a
series of photovoltaic cells where the solar rays are converted into electricity. Apart from
electricity production solar energy is also being used for heating water, cooking food etc.
Advantages of solar energy – The source of energy is absolutely ‘free’. – Solar power which
is generated in the day time can be stored to be made available in the night time as well. –
Solar power generators can be used to generate power in rural and remote areas where there
is no reach of the conventional form of energy. – Solar power generation is quite and
absolutely clean. – Solar energy is a renewable form of energy will not deplete until
thousands of years.
Wind Energy Also refer text book erach Bharucha, Page 46) The power of the wind is
harnessed to propel the blades of wind turbine attached to an electric generator to generate
wind energy. Wind energy is an effective alternative source of energy in areas where the
velocity of wind flow is high. Advantages of wind energy – Wind energy is a clean form of
energy. – The source of power generation i.e., wind is free of cost. – Wind energy is a
renewable source of energy.
Biomass Energy (Also refer text book erach Bharucha, Page 45) This is the energy
developed from the wastes of various human and animal activities like the byproducts and
wastes from timber industry, agricultural yields, municipal solid waste etc. Out of the many
alternative sources of energy this is the one which takes into account the utilization of waste
material to develop energy thereby disposing them off in a profitable and effective way.
Advantages of biomass energy – It is an environmental friendly way of energy production in

which biological mass is recycled and re-used. – The biomass will keep generating and
decomposing as part of the natural biological cycle. Therefore, biomass energy is considered
as a renewable source of energy
Geothermal Energy Also refer text book erach Bharucha, Page 48) This is the energy
tapped from the heat inside the earth. Hot rocks residing in the core of earth heat water which
emits the surface of the earth with pressure and as steam. This pressurized steam can be used
to run steam turbines to generate electricity. Advantages of geothermal energy – Similar to
other alternative energy sources, geothermal energy source is free of cost. – With a proper
power generation system in place, no harmful by-products are produced.
Tidal Power The surface of earth is 71.11% covered by water bodies especially oceans. The
tides in water rise and fall due to the gravity of sun and moon. Since we know about how the
position of moon changes we can predict the rise and fall of tides. This rise and fall of tides
can be utilized by setting up small dams and passing water through the turbines to generate
power. Advantages of tidal energy – The source of power generation is free and renewable. –
The power generated is clean and does not cause any pollution. Challenges with using
alternative energy sources As promising as the use of alternative sources of energy may
sound, it is still under research as to how to tap energy from these resources in the most
efficient and effective way. Although small power generation systems can be put in place but
power production from these resources on a large scale is still a challenge with hydroelectric
power generation being an exception. Many countries are not yet ready to move from using
conventional energy sources to the alternative energy sources as it involves a huge amount
to decommission the old power generation infrastructure and establish a new infrastructure.
Therefore, the shift is ideal to be made in phases.
Why use alternative energy sources? Alternative energy sources are available free of cost
and do not tax the environment for their usage. Power generation through alternative sources
of energy is clean and ‘green’. If we shift to use power generated from these sources, then
carbon dioxide emission from the conventional energy sources will be greatly reduced, and
the problem of global warming will be solved in a few years. Also the fast depleting
traditional energy sources can be preserved. Along with air pollution, the use of traditional
energy resources also cause soil pollution and water pollution by releasing various toxins to
the land and water. This can also be controlled reasonably. The damage that we have caused
to earth after the industrial revolution is huge and we will have to take action immediately if
we want to keep the planet sustainable for our future generations. The biggest leap that
mankind can take to prevent further damage is to start using alternative energy sources.

Growing energy needs Energy is essential to the existence of mankind. All industrial
processes like mining, transport, lighting, heating and cooling in buildings need energy. With
the growing population, the world is facing an energy deficit. Lifestyle change from simple
to a complex and luxurious lifestyle adds to this energy deficit. Almost 95% of commercial
energy is available from fossil fuels like coal and natural gas. These fossil fuels will not last
for more than a few years.Hence, we must explore alternative fuel/energy options.
Case studies: Please refer text book erach Bharucha for case studies 1-7
All case studies are important

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