Water Resources

Topics in the Chapter

• Water

→ Some facts and Figures

• Dams

• Multi-purpose river projects

→ Objectives of multi-purpose river projects

→ Disadvantages of Multi-purpose river projects

→ Movements against Multi-purpose river projects

• Rainwater Harvesting

→ How Tankas works

Water

• Water is a renewable resource

• Three-fourth of the earth’s surface is covered with water but only a small
proportion of it accounts for freshwater fit for use.

Some facts and Figures

• 96.5 percent of the total volume of world’s water is estimated to exist as

oceans and only 2.5 per cent as freshwater.

• India receives nearly 4 percent of the global precipitation and ranks 133
in the world in terms of water availability per person per annum.

• By 2025, it is predicted that large parts of India will join countries or

regions having absolute water scarcity.

Water Scarcity and need for water conservation and management

• The lack sufficient water as compared to its demand in a region is known

as Water Scarcity.

• Causes of Water Scarcity are:

→ over-exploitation

→ excessive use and unequal access to water among different social groups.
→ Large population

Dams
• A dam is a barrier across flowing water that obstructs, directs or retards
the flow, often creating a reservoir, lake or impoundment.

Multi-purpose river projects

• Multi-purpose river projects large dams that serve several purposes in

addition to impounding the water of a river and used later to irrigate
agricultural fields. For example, the Sutluj-Beas river basin, the Bhakra–
Nangal project etc.

Advantages of multi-purpose river projects are:

→ Electricity generation

→ Irrigation

→ Water supply for domestic and industrial uses

→ Flood control

→ Recreation

→ Inland navigation

→ Fish breeding

Disadvantages of Multi-purpose river projects are:

→ It affects the natural flow of river causing poor sediment flow and
excessive sedimentation at the bottom of the reservoir.

→ It destroys the habitats for the rivers’ aquatic life.

→ It submerges the existing vegetation and soil if created on the

floodplains.

→ It displaces the local people of the place where it is created.

→ These are unsuccessful in controlling floods at the time of excessive

rainfall.

→ These projects induced earthquakes, caused water- borne diseases and

pests and pollution resulting from excessive use of water.

Movements against Mult-purpose river projects

• These projects cause of many new social movements like the ‘Narmada
Bachao Andolan’ and the ‘Tehri Dam Andolan’ etc.

→ This is due to the large-scale displacement of local communities.

• Inter-state water disputes are also becoming common with regard to

sharing the costs and benefits of the multi-purpose project.

Rainwater Harvesting

•Harvesting refers to the practice of storing and using of rainwater from

the surface on which it falls.

• In hill and mountainous regions, people built diversion channels like the
‘guls’ or ‘kuls’ of the Western Himalayas for agriculture.

• In Rajasthan, ‘Rooftop rain water harvesting’ was commonly practised to

store drinking water.

• In the flood plains of Bengal, people developed inundation channels to

irrigate their fields.

• In arid and semi-arid regions, agricultural fields were converted into rain
fed storage structures that allowed the water to stand and moisten the soil.

• In the semi-arid and arid regions of Rajasthan, almost all the houses
traditionally had underground tanks or tankas for storing drinking water.

• How Tankas works:

→ Tankas were connected to the sloping roofs of the houses through a pipe.

→ Rain falling on the rooftops would travel down the pipe and was stored in
these underground ‘tankas’.

Very Short Answer Type Questions

Q1. How is freshwater obtained?

Ans. The freshwater is obtained from precipitation, surface run off and
groundwater that is continually being renewed and recharged through the
hydrological cycle.

Q2. What is hydrological cycle?

Ans. The continuous movement of water on, above and below the surface of
earth.

Q3. What is the importance of hydrological cycle?

Ans. The freshwater is mainly obtained from surface run off and
groundwater that is continually being renewed and recharged through the
hydrological cycle. All water moves within the hydrological cycle ensuring
that water is renewable resource.

Q4. What is water scarcity?

Ans. Water scarcity is the lack of sufficient available water resources to

meet the demand.

Q5. “The availability of water resources varies over space and time”. Give
reasons.

Ans. Water resources varies over space and time due to the variation in
seasonal and annual precipitation.

Q6. What percentage of the total volume of world’s water is estimated to

exist as oceans?

Ans. Approximately 96.5%.

Q7. How much per cent of the total volume of world’s water is estimated to
exist as fresh water?

Ans. Approximately 2.5.

Q8. What are the sources of fresh water?

Ans. Precipitation, surface run off and groundwater.

Q9. How is freshwater being renewed

Ans. The freshwater is being renewed through the hydrological cycle.

Q10. Mention any two regions which are expected to face water shortage.

Ans. (i) Regions having low rainfall (ii) Regions which are drought prone.

Q11. What is a dam?

Ans. ‘A dam’ is a barrier across the flowing water that obstructs dissects or
retards the flow, often creating a reservoir, lake or impoundment.

Q12. What is a multipurpose project?

Ans. A multipurpose project is that which fulfils a . variety of purposes at

the same time, for example – irrigation, generation of electricity, flood
control, fish breeding, soil conservation etc.
Q13. Who proclaimed dams as the temples of modem India?

Ans. Jawaharlal Nehru.

Q14. Why were the multipurpose river projects considered as temples of

modem India by Jawaharlal Nehru?

Ans. These would integrate development of agriculture and the village

economy with rapid industrialisation and growth of the urban economy.

Q15. Name any two social movements which have been launched against
the multipurpose projects.

Ans. Narmada Bachao Andolan and ‘Tehri Dam’ Andolan.

Q16. What was considered as a viable alternative to the multipurpose

projects and why?

Ans. The. disadvantages and rising resistance against the multipurpose

projects, has lead us to conclude that water harvesting system is a viable
alternative, both socio-economically and environmentally.

Q17. Irrigation has changed the cropping pattern of many regions with
farmers shifting to water intensive and commercial crops”. Mention its
ecological consequence.

Ans. Salinisation of the soil

Q18. What was the primary reason for launching ‘Narmada Bachao
Andolan’

Ans. Narmada Bachao Andolan was launched due to the large scale
displacement of local communities.

Q19. What is silt?

Ans. A fine soil which is formed in flood plains.

Q20. How people used to conserve or harvest water in hills and

mountainous regions?

Ans. By building diversion channels like the ‘guts’ or ‘kuls’.

Q21. How people used to harvest water in the flood plains of Bengal?

Ans. By building inundation channels to irrigate their fields.

Q22. How people harvest water in the semi- arid and arid regions of
Rajasthan?
Ans. By building underground tanks.

Q23. Many people of arid and semi-arid regions construct under-ground

rooms adjoining the water tanks. Give reason?

Ans. By beating the summer heat it would keep the room cool.

Q24. Name two techniques of roof top rain water harvesting?

Ans. (i) Recharge through hand pump. (ii) Recharge through abandoned dug
well.

Q25. Name any two states where roof top water harvesting is most
common?

Ans. Meghalaya and Rajasthan.

Q26. Define the term Tankas?

Ans. Tankas are the underground tanks for storing drinking water.

Q27. Which is the purest form of natural water?

Ans. Rainwater.

Q28. What is Kul?

Ans. It is a circular village tank from which water is released and taken
when required.

Q29. Name any two states which are involved in Krishna-Godavari-dispute?

Ans. Karanataka and Andhra Pradesh.

Q30. Name the river on which the Hirakud dam is located?

Ans. Mahanadi.

Q31. Name the river on which the Mettur dam is located?

Ans. Kaveri.

Q32. Name the river on which the Nagarjuna Sagar dam is located?

Ans. Tungabhadra.

Q33. Name the river on which the Rihand dam is located?

Ans. Son.

Q34. Name the river on which the Bhakra Nangal dam is located?
Ans. Satluj.

Q35. Name the river on which the Koyna dam is located

Ans. Krishana.

Q36. Name the river on which the Sardar Sarovar dam is located.

Ans. Narmada

Q37. What is the contribution of hydroelectricity in the total generation of

electricity.

Ans. 22%

Short Answer Type Questions

Q1. What is hydrological cycle? What is its importance

Answer: The continuous movement of water on, above and below the
surface of earth is known as hydrological cycle. The freshwater is mainly
obtained from surface run off and ground water that is continually being
renewed and recharged through the hydrological cycle. All water moves
within the hydrological cycle 5. ensuring that water is a renewable
resource.

Q2. How has agriculture aggravated the problem of water scarcity in India
Explain.

Ans. (i) Water is a basic input in agriculture. It is used for irrigation.

(ii) HYV seeds needs more water as compared to traditional seeds.

(iii) Commercialisation of agriculture has also lead to withdrawal of

groundwater at a large scale.

(iv) Overuse of groundwater is another problem associated with agriculture.

The water table has lowered in many parts of India due to its overuse.

Q3. “Water scarcity may be an outcome of large and growing population”.

Justify.

Ans. (i) A large population means more water not only for domestic use but
also to produce more food.

(ii) Most of the Indian cities are facing the problem of water due to growing
population. .

(iii) A growing population has also a direct impact on the water level.
Q4. How does urbanisation and urban lifestyle lead to over-exploitation of
water resources Explain.

Ans. (i) Most of our cities are over populated. Overpopulation leads to our
utilisation of water resources.

(ii) Urbanisation especially unplanned urbanisation adds to water pollution.

(iii) Urbanisation also damages the existing water resources especially the
river. For example, most of Indian river have been polluted by the waste of
cities.

Q5. Is it possible that an area or region may have ample water resources
but is still facing water scarcity Explain with the help of three relevant
examples. [CBSE 2013]

Ans. Yes, it is possible that an area or region may have ample water
resources but is still facing water scarcity. Most of our cities are facing this
problem.

(i)In most of our cities there is no shortage of water but the water is unfit
for consumption.

(ii)Most of our cities are in the banks of rivers, but rivers have been turned
into toxic streams.

(iii) The ever increasing population, industries and vehicles has made
matter worse by exerting pressure on existing freshwater resources.

Q6. What is importance of water Or “Water is a very important and critical

resource in India.” Support the statement by explaining any three points.

Ans. (i) Water is vital for human survival.

(ii) Water is used for transportation.

(iii) In industries water is used as a coolant.

(iv) Water is also used for power production.

(v) Water is a basic input for agriculture.

Q7. How do increasing number of industries exert pressure on existing

freshwater resources ?

Ans. (i) industries used water as coolant, raw material, solvent, etc.

(ii) Industries release harmful chemicals which contaminates water.

(iii) Most of the Indian rivers are polluted due to toxic chemicals which are
released by industries.

Q8. What are dams? How do these help to conserve and manage water

Ans. A dam is a barrier across flowing water that obstructs, directs or

retards the flow often creating a reservoir, lake or impoundment.

(i)Dams were traditionally built to impound rivers and rainwater that could
be used later to irrigate agricultural fields.

(ii) Dams are also source of perennial canals.

Q9. Distinguish between a dam and a multipurpose project.

Ans. Dam :

1. A dam is barrier across the flowing water that obstructs, dissects or

retards the flow, often creating a reservoir, lake or an impoundment

2. It is a traditional concept.

Multipurpose project.

1. A multipurpose project is that which fulfils a variety of purposes at the

same time, for example – irrigation, generation of electricity, flood control,
fish breeding, soil conservation, etc.

2. It is a modern concept.

Q10. Who proclaimed the dams as the temples of modern India Give reason.

Ans. Jawaharlal Nehru proudly proclaimed the dams as the ‘temples of

modem India’; the reason being that it would integrate development of
agriculture and the village economy with rapid industrialisation and growth
of the urban economy.

Q11.‘Multipurpose projects and large dams have also been the cause of
many social movement’. Name any two such movements. Why these
movements were launched

Ans. Multipurpose projects and large dams have also been the cause of
many new social movements like the ‘Narmada Bachao Andolan’ and ‘Tehri
Dam Andolan’ etc. Resistance to these projects has primarily been due to
the large – scale displacement of local communities. Local people often had
to give up their land, livelihood and their meagre access and control over
resources for the greater good of the nation.
Q12. How do the dams create conflicts between the people

Ans. (i) The dams have created conflicts between people wanting different
uses and benefits from the same water resources.

(ii) Inter-state water disputes are becoming common with regard to sharing
the costs and benefits of the Projects.

(iii) The landowners, the rich farmers, industrialists and urban centres are
benefitting at the cost of local communities.

(iv) In Gujarat, the Sabarmati – basin farmers were agitated and almost
caused a riot over the higher priority given to water supply in urban areas,
particularly during droughts. Inter – state water disputes are also becoming
common with regard to sharing the costs and benefits of the multipurpose
project.

Q13. How has irrigation changed the cropping pattern? What is its impact
on the social landscape?

Ans. Due to irrigation facilities many farmers have shifted to water intensive
and commercial crops. For example, Punjab has become major producer of
rice in spite of low rainfall. Impact on social landscape: This transformation
has widens the gap between rich and poor. The rich and mighty who can
afford higher inputs has become more rich whereas the poor have failed to
get benefit due to lack of capital.

Q14. Explain three ways in which irrigation schemes have changed the
social landscape of the region?

Ans. (i) Displacement of the local people : Local people often had to give up
their land, livelihood and their meagre access and control over resources
for the greater good of the nation.

(ii) Social movements : Multipurpose projects and large dams have also
been the cause of many new social movements like the ‘Narmada Bachao
Andolan’ and the ‘Tehri Dam Andolan’, etc.

(iii) Widening the gap between rich and poor : Multipurpose projects have
widened the gap between rich and poor. The landlords, large farmers and
industrialist are getting benefit at the cost of poor.

Q15. “Multipurpose projects have failed to achieve the purpose for which
they were built”. Justify by giving reasons?
Ans. (i) These dams were constructed to control floods but they have
triggered floods due to sedimentation in the reservoir.

(ii) Moreover, the big dams have mostly been unsuccessful in controlling
floods at the time of excessive rainfall.

(iii) Many a time authorities are forced to release water from dams during
heavy rainfall.

Q16. What is rainwater harvesting What is its importance?

Ans. It is a technique of increasing the recharge of ground water by

capturing and storing rainwater by constructing structures such as
percolating pits, check dams, etc.

Importance:-
(i) Rainwater harvesting is the need of hour as demand for water is
increasing day by day.

(ii) Rainwater harvesting reduces pressure on existing water resources.

(iii) It is cheap source of water supply.

(iv) It helps in recharging groundwater.

(v) The rainwater store is extremely reliable source of drinking water when
all other sources are dried up.

Q17. (i) What is a multipurpose project? (ii) Why did Pandit Jawahar Lal
Nehru proclaim the river dams as the ‘Temples of Modem India?’ Explain
the main reason.

Ans. (i) A multipurpose project is that which fulfils a variety of purposes at

the same time, for example – irrigation, generation of electricity, flood
control, fish breeding, soil conservation, etc.

(ii) It would integrate development of agriculture and the village economy

with rapid industrialisation and the growth of urban economy.

Q18. Explain the rooftop rainwater harvesting technique.

Ans. (i) Rooftop rainwater is collected using a PVC pipe.

(ii) Collected water is filtered using sand and bricks.

(iii) Underground pipe is used to take the water to the sump for immediate
usage.
(iv) Excess water from the sump is taken to the well.

(v) Water from the well recharges the underground water.

Q19. Why are different water harvesting systems considered a viable

alternative both socio economically and environmentally in a country like
India?

Ans. (i) Water harvesting is a very cheap and affordable method of

conservation of water.

(ii) Indian people have in-depth knowledge of rainfall regime and soil type.
They have developed techniques to harvest rainwater, groundwater, rain
water and flood water in keeping with the local ecological conditions and
their water needs.

(iii) Rainwater harvesting techniques are more environmental friendly as

compare to multipurpose river projects.

Q20.What is water scarcity? Mention any four factors responsible for water
scarcity? Or What is meant by water scarcity and give any two causes of
water scarcity

Ans. Shortage of water as compared to its demand is known as water

scarcity. Factors responsible :

(i)Overexploitation of water sources.

(ii)Improper management.

(iii) Unequal access of water among different social groups.

(iv) Industrialisation and urbanisation.

Q21. Explain various problems associated with poor people due to

construction of large dams.

Ans. (i) Construction of large dams leads to the large-scale displacement of

the local communities.

(ii) Local people have to give up their land and livelihood.

(ii) Poor people lose meagre access and control over resources for the
greater good of the nation.

(iv) The displaced people do not get full rehabilitation facilities from the
government,
(v) The landless people have to work as labourers in factories or
construction sites. Their lives become miserable.

Q22. Name any two movements that have been started to oppose
multipurpose projects. Who are benefitted from such projects?

Ans.(1) Two movements that have been started to oppose multipurpose

projects are:

(i)Narmada Bachao Andolan was started against the Sardar Sarovar Dam
being built across the Narmada river in Gujarat.

(ii) Tehri Dam Andolan – Resistance to these projects has primarily been due
to the large-scale displacement of local communities.

(2) The landowners and large farmers, industrialists and a few urban
centers are benefitted from such projects.

Q23. Why is rooftop rainwater harvesting important in Rajasthan Explain.

Ans. (i) The rainwater stored in tankas is an extremely reliable source of

drinking water when all other sources are dried up.

(ii) Rainwater is considered the purest form of natural water.

(iii) Many houses constructed underground rooms adjoining the tanka to

beat the summer heat as it would keep the room cool.

(iv) There is lack of perennial rivers in Rajasthan.

(v) The rainfall is not reliable in this region.

Q24. What role do “Guls” or “Kuls” of the Western Himalayas and “Khadin”
and “Johads” in parts of Rajasthan play Describe?

Ans. (i) In Western Himalayas people build diversion channels like ‘guls’ or
‘kuls’.

(ii) In arid and semi-arid regions, agricultural fields were converted into
rain-fed storage structures.

(iii) These allowed the water to stand and moisten the soil like the ‘Khadins’
in Jaisalmer and ‘Johads’ in other parts of Rajasthan.

Q25. “Need of the hour is to conserve and manage our water resources.”
Mention any four reasons. Suggest any two ways to conserve water?

Ans. (i) To safeguard ourselves from health hazards.

(ii) To ensure food security.

(iii) To prevent degradation of our natural ecosystem.

(iv) To save the future generations from water crisis.

Suggestions :

(i) Turn off the tap while brushing.

(ii) We should spread awareness regarding water conservation.

(iii) Rainwater harvesting.

Q26. How is industrialisation responsible for water scarcity? Explain.

Suggest any two ways to check water pollution.

Ans. (i) The ever increasing number of industries has made matter worse by
exerting pressure on the existing freshwater resources.

(ii) Industries need power which is produced from water. The power is
produced by the multipurpose projects.

(iii) Chemicals and gases released by industries also pollutes the water.

Suggestions :

(i)Minimising use of soaps and detergents.

(ii) Minimising use of fertilizers.

Q27. Large multipurpose projects also lead to land degradation.’ Explain?

Ans. Multipurpose projects lead to land degradation because :

(i)Irrigation has changed the cropping pattern of many regions with farmers
shifting to water intensive crops. This has led to the salinization of the soil.

(ii)Regulating and damming of rivers affect the natural flow of rivers

causing poor sediment flow.

(iii) The flood plains are deprived of silt.

(iv) Multipurpose projects induce pollution which leads to land degradation.

Q28. Explain the term ‘tankas’. Where were tankas built in India?

Ans. (i) The tankas were part of the well-developed rooftop rainwater
harvesting system and were built inside the main house or the courtyard.
They are built for storing drinking water. A tank could be 6.1 meters deep,
4.27 meters long and 2.44 meters wide.

(ii) The tankas were built in the semi-arid and arid regions of Rajasthan,
particularly in Bikaner, Phalodi and Barmer.

Q29. Highlight any three hydraulic structures as part of water management

programmes initiated in ancient India along with the period when they were
built.

Answer. • A sophisticated water harvesting system channeling the flood

water of river Ganga was built at Sringaverapura near Allahabad in the 1st
century B.C.

• In the 11th century, Bhopal Lake, one of the largest artificial lakes of its
time was built.

• The tank in Hauz Khas, Delhi was constructed by Iltutmish in the 14th
century to supply water to the Siri Fort Area.

Q30. Why is groundwater a highly overused resource?

Answer. Groundwater is a highly overused resource because of the

following reasons:

• Due to large and growing population and consequent greater demands for
water and unequal access to it.

• To facilitate higher food grain production for large population, water

resources are being over exploited to expand irrigated areas and dry season
agriculture.

• In the housing societies or colonies in the cities, there is an arrangement

of own ground water pumping devices to meet water needs.

Q31. Describe any three traditional methods of rainwater harvesting

adopted in different parts of India. OR Describe any three traditional
methods of rainwater harvesting adopted in different parts of India.

Answer. • In hilly and mountainous regions, people build diversion channels

like ‘gul’ or ‘kul’ in Western Himalaya for agriculture.

• Roof-top rainwater harvesting was commonly practiced to store drinking

water particularly in Rajasthan.

• In West Bengal, people develop inundation channels to irrigate their

fields.
Q32. Explain the working of underground tanks as a part of roof top
rainwater harvesting system practiced in Rajasthan. OR Discuss how
rainwater harvesting in semiarid regions of Rajasthan is carried out.

Answer. • In semi-arid and arid regions of Rajasthan almost all the houses
traditionally had underground tanks for storing drinking water. They are
extremely reliable source of drinking water when other sources are dried
up. This is considered the purest form of natural water.

• The tanks can be as large as big rooms.

• The tanks were part of the well-developed rooftop rainwater harvesting

system.

Q33. Explain the quantitative and qualitative aspects of water scarcity? Or

Water is available in abundance in India even then scarcity of water is
experienced in major parts of the country. Explain with four examples.

Ans. (i) Quantitative aspect : This aspect is related to the availability of

water resources. The availability of water resources varies over space and
time mainly due to variations in seasonal and annual precipitation.
However, water scarcity in most cases is caused by over-exploitation,
excessive use and unequal access to water among different social groups.

(ii) Qualitative aspect : Now, let us consider another situation where water
is sufficiently available to meet the needs of the people, but, the area still
suffers from water scarcity. This scarcity may be due to bad quality of water.
Lately, there has been a growing concern that even if there is ample water
to meet the needs of the people, much of it may be polluted by domestic and
industrial wastes, chemicals, pesticides and fertilizers used in agriculture,
thus, making it hazardous for human use.

Q34. How are multipurpose projects and large dams the cause of social
movements?

Ans. Multipurpose projects and large dams are the cause of social
movements:

•Multi-purpose projects and large dams have been the cause of many new
environmental movements like the ‘Narmada Bachao Andolan’ and the
‘Tehri Dam Andolan’.

•Resistance to these projects has primarily been due to the large-scale

displacement of local communities.
•Local people often had to give up their land, livelihood, and their meagre
access and control over resources for the greater good of the nation.

•But these local people are not benefited much from these projects. The
benefited ones are the landowners and large farmers, industrialists, and a
few urban centres.

Long Answer Type Questions

Q1. How have the growing population, industrialisation and urbanisation

led to water scarcity Explain. Or Explain any four reasons responsible for
water scarcity in India. Or How have industrialisation and urbanisation
aggravated water scarcity in India Or Give three reasons for water scarcity
in post independent India. Or ‘Three-fourths of the earth’s surface is
covered with water but there is still scarcity of water across the globe.’
Explain giving three reasons.

Ans. (i) Growing population : Growing population is one of the basic factors
which is responsible for the scarcity of water. Most of our cities are facing
this problem due to overpopulation. A large population means more water
not only for domestic use but also to produce more food.

(ii) Commercialisation of agriculture : After the success of Green

Revolution, our farmers are producing commercial crops. The commercial
crops need more water and other inputs. Assured means of irrigation like
tube wells and wells are responsible for the falling groundwater levels.

(iii) Industrialisation : The post independent India witnessed intensive

industrialisation and urbanisation. Today, large industrial houses are
common in the form of industrial units of many MNCs (Multinational
Corporations). The ever increasing number of industries has made matters
worse by exerting pressure on the existing freshwater resources. Industries,
apart from being heavy users of water, also require power to run them.
Much of this energy comes from the hydroelectric power.

(iv) Urbanisation : Urbanisation has also aggravated the problem of water

scarcity. Most of our cities are overpopulated. Overpopulation leads to over-
utilisation of the water resources, and also pollutes the existing resources.

Q2. How do the multipurpose river projects affect the aquatic life Explain?
Or Explain the ecological problems being faced due to the multi-purpose
river projects.
Ans. In recent years, the multi-purpose projects and large dams have come
under great scrutiny and opposition for a variety of reasons :

(i)Regulating and damming of rivers affect their natural flow causing poor
sediment flow and excessive sedimentation at the bottom of the reservoir,
resulting in rockier streambeds and poorer habitats for the rivers, as well as
the aquatic life.

(ii) Dams also fragment rivers making it difficult for the aquatic fauna to
migrate, especially for spawning.

(iii) The reservoirs that are created on the flood. Plains also submerge the
existing vegetation and soil leading to its decomposition over time.

(iv) Irrigation has also changed the cropping pattern of many regions with
farmers shifting to water intensive and commercial crops. This has great
ecological consequences like salinization of the soil.

Q3. How are multipurpose projects and large dams the cause of social
movements?

Ans. Multipurpose projects and large dams are the cause of social
movements:
 Multi-purpose projects and large dams have been the cause of many
new environmental movements like the ‘Narmada Bachao Andolan’
and the ‘Tehri Dam Andolan’.
 Resistance to these projects has primarily been due to the large-scale
displacement of local communities.
 Local people often had to give up their land, livelihood, and their
meagre access and control over resources for the greater good of the
nation.
 But these local people are not benefited much from these projects.
The benefited ones are the landowners and large farmers,
industrialists, and a few urban centers.
Q4. Why is there an urgent need to conserve and manage our water
resources Mention three reasons? Or Why is it necessary to conserve water
resources in India Explain. Or Why is it essential to conserve, and manage
our water resources Explain any three reasons. Or Why we should conserve
our water resources Explain any three reasons.

Ans. (i) Precondition for life : Water is necessary for life on earth. It is
believed that life originated in water before it invaded land. Water is in fact
a precondition of life.
(ii) Water essential for crops: Cultivation of crops depends on the
availability of water. Water dissolves minerals and other nutrients in the
ground. The roots of the plants draw this nutritious water for the soil. India
is an agricultural country so availability of water is a must.

(iii) Water and industries : Industries need water as coolant, solvent, raw
material, etc.

(iv) Water for daily life : Water is also used for drinking and domestic
consumption. The growing urbanisation with its modern lifestyle has been
demanding greater share of water day by day.

(v) Water an important component of ecosystem : Conservation of water is

also important to prevent degradation of our natural ecosystems.

(vi) Water scarcity : It is essential to conserve and manage water because

its overuse and misuse has lead to water scarcity.

Q5. Examine the importance of the river valley projects in the development
of hydel power and irrigational facilities in India. Or Give any four
objectives of the multipurpose river valley projects.

Ans. (i) Generation of Power (electricity): These multipurpose projects are

the main source of power generation. According to the Economic Survey,
2013, these produce more than 39,788.40 MW power. They provide us neat,
pollution free and cheapest energy which is the backbone of industry and
agriculture.

(ii) Flood Control : These projects control the floods because water can be
stored in them. These projects have converted many ‘rivers of sorrows’ into
‘rivers of boon’. For example, the river Kosi.

(iii) Soil Conservation : They help to conserve the soil because they slow
down the speed of water.

(iv) Irrigation : These projects are the main source of irrigation for our
country. These irrigate the fields during the dry seasons. Many perennial
canals have been dug and they irrigate dry areas.

Q6. “In recent years, the multipurpose projects and large dams have come
under great scrutiny.” Give reasons? Or Mention any four disadvantages of
multi purpose projects? Or . How may the multipurpose river valley projects
become harmful for the country Explain with four examples. Or Why are
multipurpose projects facing resistance Explain with three reasons.
Answer: (i) Adverse effect on the fertility of the soil : Due to the
construction of dams, there are no annual floods in the river. And because of
this, the soil of the downstream region does not get nutrient rich “silt”. This
decreases the fertility of the soil.

(ii) Adverse impact on aquatic life: Due to the construction of dams on the
rivers, the fish in the downstream area do not get sufficient nutrient
material. Regulating and damming of rivers affect the natural flow of water
causing poor sediment flow downward, and excessive sedimentation at the
bottom of reservoir, resulting in rockier stream beds and poorer habitats for
the rivers aquatic life. Dams also fragment rivers making it difficult for
aquatic fauna to migrate for spawning i.e., to produce eggs.

(iii) Displacement of local communities : The building of large dams results

in displacement of local communities. The local people often have to give up
their land and livelihood and their meagre access and control over
resources for the greater food of the nation.

(iv) Change in the cropping pattern : The multipurpose projects are

responsible for providing assured means of irrigation to farmers. Due to
this, most of the farmers have changed the cropping pattern shifting to
water intensive and commercial crops. This has led to salinization of soil
leading to ecological imbalance.

Q7. Write the features of the ‘tankas’ built in the houses of Bikaner, Phalodi
and Banner?

Ans. (i) The tanks could be as large as a big room; one household in Phalodi
had a tank that was 6.1 meters deep, 4.27 meters long and 2.44 meters
wide.

(ii) The tankas were part of the well-developed rooftop rainwater harvesting
system and were built inside the main house or the courtyard.

(iii) They were connected to the sloping roofs of the houses through a pipe.

(itv) Rain falling on the rooftops would travel down the pipe and was stored
in these underground tankas.

(v) The first spell of rain was usually not collected as this would clean the
roofs and the pipes. The rainwater from the subsequent showers was then
collected.

Q8. What is bamboo drip irrigation Mention any two features of it.
Ans. Bamboo Drip Irrigation system is a 200 year old system of tapping
stream and spring water by using bamboo pipe and transporting water from
higher to lower regions through gravity. Features of bamboo drip irrigation :

(i) About 18-20 liters of water enters the bamboo pipe system, get
transported over hundreds of meters and finally reduces to 20-80 drops per
minute at the site of the plant.

(ii) Bamboo drip irrigation system is practiced in Meghalaya. Bamboo pipes

are used to divert perennial springs on the hilltops to the lower reaches by
gravity.

(iii) The channel sections, made of bamboo, divert water to the plant site
where it is distributed into branches.

Q9. “Overpopulation or large and growing population can lead to water

scarcity.” Explain. Mention any two lessons which you have learnt from this.

Ans. Overpopulation or large and growing population can lead to water

scarcity as :

(i)More population means more demand for water.

(ii)A large population means more water not only for domestic use but also
to produce more food.

(iii) To facilitate higher food grain production, water resources are being
over exploited to expand the irrigated areas and the dry season agriculture.

(iv) Overutilization of water results in lowering of the groundwater levels.

Lessons :

(i)There is need to check the growth of population.

(ii) Human beings need to care for nature.

Q10. How have intensive industrialization and urbanization posed a great

pressure on existing fresh water resources in India. Explain.

Answer. • Large scale industrialization and urbanization have posed a great

pressure on existing fresh water resources as many multinational
companies are being set up in India who is the heavy consumers of water
for processing, discharge of effluents and as an energy resource.

• Hydroelectricity produced for industrial units have not only posed a great
threat to the availability of fresh water resources but also contributed to
bad quality of water with large growing number of urban centers and
population.

• Modern lifestyle of the urban people has created more demand for water
both for domestic purposes and increased consumption of energy.

• In housing colonies to meet the needs of population, water resources are

over-exploited resulting in depletion of ground water resources.

• Fresh water needs to be protected from industrial pollution and wastage

of water in cities.

•Multiplying urban centres with large and dense populations and urban
lifestyles has not only added to water and energy requirements but has
further aggravated the problem.

Q11. Explain any three reasons responsible for water scarcity in India? OR
Water is available in abundance in India even then scarcity of water is
experienced in major parts of the country. Explain it with four examples.

Answer. • The availability of water resources varies over space and time,
mainly due to the variations in seasonal and annual precipitation.

• Over-exploitation, excessive use and unequal access to water among

different social groups.

• Water scarcity may be an outcome of large and growing population and

consequent greater demands for water. A large population means more
water to produce more food. Hence, to facilitate higher food-grain
production, water resources are being over exploited to expand irrigated
areas for dry-season agriculture.

• Most farmers have their own wells and tube wells in their farms for
irrigation to increase their production. But it may lead to falling
groundwater levels, adversely affecting water availability and food security
of the people. Thus, inspite of abundant water there is water scarcity.

Q11. Why is roof top water harvesting important in Rajasthan? Explain. OR

Explain the working of underground tanks as a part of the rooftop rainwater
harvesting system practiced in Rajasthan.

Answer. Rainwater is commonly referred to as Palar Pani in the arid and

semi-arid regions of Rajasthan. In the semi-arid and arid regions of
Rajasthan, particularly in Bikaner, Phalodi, and Barmer, almost all the
houses traditionally had underground tanks for storing drinking water.
Roof top water harvesting is important in Rajasthan because:

• It was commonly practised to store drinking water.

• The rainwater can be stored in the tanks till the next rainfall, making it an
extremely reliable source of drinking water when all other sources are dried
up, particularly in the summers.

• Rain water, or palar pani, as commonly referred to in these parts, is

considered the purest form of natural water. The tanks were part of the
well-developed rooftop rainwater harvesting system.

• Many houses construct underground rooms adjoining the ‘tanka’ to beat

the summer heat as it would keep the room cool. They were connected to
the sloping roofs of the houses through a pipe.

• Some houses still maintain the tanks since they do not like the taste of tap
water. The first spell of rain was usually not collected as this would clean
the roofs and the pipes. The rainwater from the subsequent showers was
then collected.

Q12. Compare the advantages and disadvantages of multi-purpose river

valley projects.

Ans. Advantages:

•They provide water for irrigation.

•They provide water for electricity generation

•They provide water supply for domestic and industrial uses.

•Used for recreation and inland navigation.

•These projects help in controlling the floods.

•Provide recreation

•Useful for fish breeding.

Disadvantages:

•Regulating and damming of rivers affect their natural flow causing poor
sediment flow and excessive sedimentation at the bottom of the reservoir,
resulting in rockier stream beds and poorer habitats for the rivers’ aquatic
life.
•Dams also fragment rivers making it difficult for aquatic fauna to migrate,
especially for spawning.

•The dams have triggered floods due to sedimentation in the reservoir and
the release of excess water during heavy rains.

•Multipurpose projects induced earthquakes, caused water-borne diseases,

and pests, and lead to pollution resulting from excessive use of water.

•Irrigation has changed the cropping pattern of many regions with farmers
shifting to water-intensive and commercial crops. This has great ecological
consequences like salinization of the soil.

•The dams increase the social gap between the richer landowners and the
landless poor.

•The dams create inter-state water disputes with regard to sharing the costs
and benefits of the multi-purpose project.

Q13. Why are different water harvesting systems considered a viable

alternative both socioeconomically and environmentally in a country like
India?

Ans. Keeping into view the disadvantages and rising resistance against the
multi-purpose projects, water harvesting system is considered a viable
alternative both socio-economically and environmentally.

• In ancient India also alongwith the sophisticated hydraulic structures,

there existed an extraordinary tradition of various water harvesting
systems.

• People adopted different techniques in different areas. In hilly regions

people built diversion channels like the ‘guls’ or ‘kuls’ for agriculture.

• Roof-top rain water harvesting was commonly practised to store drinking

water, particularly in Rajasthan.

• In the flood plains of Bengal, people developed inundation channels to

irrigate their fields.

• Khadins, Johads and Tanks are the forms of rain water harvesting
practised in Rajasthan.

Q13. What is water scarcity and what are its main causes?

Answer. Water scarcity is the lack of freshwater resources to meet the

demands of water usage within a region.
Main causes of water scarcity:

•Water scarcity in most cases is caused by over-exploitation, excessive use,

and unequal access to water among different social groups.

•Water scarcity may be an outcome of a large and growing population and

consequent greater demands for water and unequal access to it.

•To facilitate higher food-grain production, water resources are being over-
exploited to expand irrigated areas for dry-season agriculture.

•Intensive industrialization and urbanization exerted pressure on existing

freshwater resources.

•Even if water is sufficiently available to meet the needs of the people,

much of it is maybe polluted by domestic and industrial wastes, chemicals,
pesticides, and fertilizers used in agriculture, thus causing water scarcity.

NB: There can be more questions from the chapter, so read the text
book property to be able to answer any questions.