WATER RESOURCES
NCERT TEXTBOOK QUESTIONS
Questions in the Exercise
Q.1.
Choose the right answer from the four alternatives given below :
(i) Water becomes a renewable and rechargeable resource due to which of the
following reasons?
(a) Water table (b)
Hydrological cycle
(c) Oceans and seas (d)
Surface runoff
Ans. (b)
Hydrological cycle
(ii) Which of the following statements is not an argument in favour of
multipurpose river projects?
(a) Multipurpose projects
bring water to those areas which suffer from water scarcity.
(b) Multipurpose projects help
to control floods by regulating water flow.
(c) Multipurpose projects lead
to large scale displacements and loss of livelihood.
(d) Multipurpose projects
generate electricity for our industries and our homes.
Ans. (c)
Multipurpose projects lead to large scale displacements and loss of livelihood.
Q.2. Based on the information given below, classify each of the situations as
‘suffering from
water scarcity’ or not suffering from water scarcity.
(a) Region with high annual
rainfall.
— Not suffering from water
scarcity – because it receives good natural freshwater supply
which is renewed annually
during the rainy periods.
(b) Region having high annual
rainfall and large population.
— Suffering from water
scarcity, because large population means more requirement of
water for foodgrain
production, industrialisation and urbanisation as well for domestic
consumption which exhaust
available water resources due to over-exploitation.
(c) Regions having high annual
rainfall but water is highly polluted.
— Suffering from water
scarcity – because the available fresh water sources, inspite of
being renewed, are rendered
useless due to pollution. Pollution turns the water sources
toxic and they become
hazardous and unusable for human consumption.
(d) Regions having low
rainfall and low population.
— Not suffering from water
scarcity – because the low demand for water by lower
population compensates for the
low water availability.
Q.3. Here are some false statements. Identify the mistakes and rewrite them
correctly.
(a) Multiplying urban centres
with large and dense population and urban lifestyle have helped
in proper utilisation of water resources.
Correct :
Multiplying urban centres with large and dense population and urban lifestyles
have not
only added to water and energy
requirements but have further aggravated the problem.
(b) Regulating and damming of
rivers do not affect the river’s natural flow and its
sediment flow.
Correct :
Regulating and damming of rivers affect the river’s natural flow causing poor
sediment
flow.
(c) In Gujarat, the Sabarmati
basin farmers were not agitated when higher priority was given
to water supply in urban
areas, particularly during droughts.
Correct :
In
Gujarat, the Sabarmati basin farmers were agitated and almost caused a riot when
higher
priority was given to water
supply in urban areas, particularly during droughts.
(d) Today in Rajasthan, the
practice of rooftop rainwater water harvesting has gained
popularity despite
high water availability due to Rajasthan Canal.
Correct :
Today in Rajasthan, the practice of rooftop rainwater harvesting is on the
decline on
account of high water
availability due to Rajasthan Canal.
Q.4. Compare the advantages and disadvantages of multipurpose river projects.
Ans.
Multipurpose river projects provide us with multiple benefits like (i)
irrigation
(ii) hydroelectricity for out
industries and homes (iii) water for domestic and industrial use
regulating flow of water and
helping (iv) flood control (v) recreational facilities (vi) inland
navigation and (vii)
pisciculture and (viii) soil conservation through afforestation. The many
purposes for which the
impounded water of the these present day dams termed as multipurpose
projects, are used, integrates
progress of agriculture with rapid industrialisation. They bring
water to those areas which
suffer from water scarcity.
But the multipurpose river
projects have come under great scrutiny in recent times because of
(i) their failure to fulfil
their basic objectives like flood control and the disadvantages resulting
out of building of such
projects. (ii) Regulating and damming of rivers affect the natural flow
of the rivers, cause exessive
sedimentation and adversely affect aquatic life. (iii) The reservoirs
that are created in the
floodplains overflow and submerge the existing vegetation and soil,
consequently leading to their
decomposition. (iv) Multipupose projects lead to large scale
displacement of local
communities and to loss of their livelihood (v) Excessive use of water,
and over-irrigation on account
of the projects lead to land degradation and cause waterborne
disease, pests and pollution.
Q.5. Three-fourths of the world is covered with water and water is a renewable
resource. Yet
many countries and regions around the globe suffer from water scarcity. Explain.
What is water scarcity and what are its main causes?
Ans.
Shortage in the availability of usable water resource is known as water
scarcity.
Three-fourth of the world is
covered with water. But out of that 96.5 percent of water is
estimated to exist as oceans
and seas which are saline in nature and unfit for general use. Only
2.5 percent of the total
volume of the world’s water exists as freshwater. Though water is
continuously renewed and
recharged by the hydrological cycle, it is also being continuously
used by the ever increasing
population. Overuse and often misuse is leading to scarcity of this
valuable resource. Hence, many
countries and regions around the globe suffer from water
scarcity.
Regions of low and erratic and
uncertain rainfall face water scarcity. But water scarcity may
be faced also in regions of
high rainfall if the population is large. A large population means
more requirement of water for
producing more food, more consumption of water for domestic
purposes and for expanding
industries. These exhaust the available water resource and create
water scarcity.
In some areas unequal access
to water among different social groups creates water scarcity.
Pollution of existing water
bodies due to discharge of industrial effluents and wastes, spoil the
available water and create
water scarcity.
Q.6. Describe how modern adaptations of traditional rainwater harvesting methods
are being
carried out to conserve and store water.
Ans.
Rooftop rainwater harvesting in Gendathur village of Mysore, Karnataka is an
example of
modern adaptation of
traditional rainwater harvesting methods being carried out to conserve
and store water. Gendathur is
a remote, backward village in Mysore, Karnataka, which has
earned the rare distinction of
being rich in rainwater because of successful rainwater harvesting
by the villagers.
Gendathur receives an annual
precipitation of 1000 mm. The villagers have utilised this
rainwater to meet their water
need by collecting it throught rooftop rainwater harvesting system
in their individual houses.
Nearly 200 households in the village have installed the system. As
such, with 80 percent of
collection efficiency of the annual precipitation and about 10 fillings
of rain, every house in
Gendathur can collect and use about 50,000 litres of water annually.
The net amount of rainwater
estimated to be harvested annually from all the households
amount to 10,00,000 litres.
Tamil Nadu is the first and
the only state of India which has made modern rooftop rainwater
harvesting structure
compulsory to all houses acrosss the state.
Recharging of groundwater by
means of dug wells, pits, handpumps etc., is a new concept of
rainwater harvesting being
adopted in many areas to conserve and store water.
Q.7. Discuss how rainwater harvesting in semi-arid regions of Rajasthan is
carried out.
Ans.
In
some of the semi-arid regions of Rajasthan, agricultural fields were converted
into rain-fed
storage structures that
allowed water to stand and moisten the soil. These structures are locally
known as ‘johads’. In the arid
areas of Jaisalmer such structures are known as ‘Khadins’.
In the semi-arid and arid
regions of Rajasthan, particularly in Bikaner, Phalodi and Barmer,
almost all the houses,
traditionally, had big underground tanks called ‘tankas’ for storing
drinking water.
The tankas were part of the
well-developed rooftop rainwater harvesting system. The tanks
could be as large as a big
room, one household in Phalodi had a tank that was 6.1 metres deep,
4.27 metres long and 2.44
metres wide. Rainwater, commonly known as ‘palar pani’ in local
language, is considered as the
purest form of natural water in this region and was stored for
drinking purpose.
The water was collected by
channelising rainwater through pipes from the sloping rooftop to
the underground tanks built
inside the house or courtyard.
The first spell of rain was
usually not collected as it would clean the roofs and pipes. As a
result it would be dirty, and
unfit for drinking purpose.
The rainwater from the
subsequent showers was then collected and stored in the tankas till the
next rainfall, making it an
extremely reliable source of drinking water when all others sources
dried up, particularly during
summers.
Many houses constructed
underground rooms adjoining the tankas to combat the summer heat
as it would keep the rooms
cool naturally.
The practice of rainwater
harvesting, is however, declining in Western Rajasthan at present
because the perennial Indira
Gandhi Canal or Rajasthan Canal provides plenty of water to the
region, throughout the year.
MULTIPLE CHOICE QUESTIONS
Q.1. Which of the following data shows the percentage of global precipitation
that is received
by India?
(a) 96.5 per cent (b) 30 per
cent (c) 4 per cent (d) 2.5 per cent
Ans. (c)
Q.2. Which of the following areas would you immediately associate with water
scarcity?
(a) Deserts of Rajasthan (b)
The Ganga Plains
(c) Hills of North-Eastern
India (d) Coastal areas of Orissa
Ans. (a)
Q.3. Which of the following is a reason for water scarcity in a region with
sufficient water to
meet the requirements of the people?
(a) Huge population (b) Less
rainfall (c) Power requirement (d) Pollution
Ans. (d)
Q.4. Which of the following contributes approximately 22 per cent of the total
electricity
produced in India today?
(a) Solar power (b)
Hydroelectric power
(c) Industries (d) Geothermal
energy
Ans. (b)
Q.5. Which of the following problems arises due to water pollution?
(a) Sedimentation of water
bodies (b) Water-borne diseases
(c) Discharge of industrial
waste (d) Spawning of aquatic life
Ans. (b)
Q.6. Which of the following hydraulic structures is not a feature of ancient
times?
(a) Multipurpose river valley
projects (b) Dams built of stone rubble
(c) Reservoirs or lakes (d)
Embankments and canals
Ans. (a)
Q.7. Which of the following is one of the largest artificial lakes of ancient
India built in the
11th century?
(a) Govindsagar Lake (b) Hauz
Khas (c) Bhopal Lake (d) Dal Lake
Ans. (c)
Q.8. Which of the following hydraulic structures was constructed by Iltutmish in
the 14th
century for supplying water to Siri Fort area?
(a) Water harvesting at
Sringaverapura near Allahabad
(b) Bhopal Lake
(c) Tank in Hauz Khas, Delhi
(d) Irrigation work at
Nagarjunakonda
Ans. (c)
Q.9. Which of the following hydraulic structures is built in river basins?
(a) Lakes (b) Dams (c) Tanks
(d) Water harvesting
Ans. (b)
Q.10. In which of the following areas can you find one of the oldest
water-harvesting systems
of India?
(a) Sringaverapura near
Allahabad (b) Kalinga, Orissa
(c) Bennur, Karnataka (d)
Nagarjunakonda, Andhra Pradesh
Ans. (a)
Q.11. For which of the following purposes were dams traditionally built?
(a) For generating electricity
(b) For supplying water to industries
(c) For flood control (d) To
impound river and rain water for irrigation
Ans. (d)
Q.12. Which of the following multipurpose projects is found in the Satluj-Beas
river basin?
(a) Hirakud Project (b)
Damodar Valley Corporation
(c) Bhakra Nangal Project (d)
Rihand Project
Ans. (c)
Q.13. On which of the following rivers is the Hirakud dam constructed?
(a) Satluj (b) Beas (c)
Mahanadi (d) Narmada
Ans. (c)
Q.14. On which of the following issues did the Narmada Bachao Andolan first
focus?
(a) Benefits of irrigation to
landless farmers
(b) Environmental issues
related to submergence of trees under the dam water
(c) Rehabilitation of the
people displaced due to construction of the dam
(d) Economic issues of wastage
of money for the construction of the dam
Ans. (b)
Q.15. In which of the following areas were farmers agitated when higher priority
was given to
water supply in urban areas, particularly during drought?
(a) Krishna-Godavari basin (b)
Koyna basin, Maharashtra
(c) Sabarmati basin, Gujarat
(d) Rihand basin, Uttar Pradesh
Ans. (c)
Q.16. Which of the following state governments have raised the Krishna-Godavari
dispute?
(a) Karnataka and Andhra
Pradesh (b) Gujarat and Rajasthan
(c) Maharashtra and Madhya
Pradesh (d) Karnataka and Maharashtra
Ans. (a)
Q.17. On which of the following rivers are the Tilaiya, Panchet, Maithon, Konar
and Bokaro
dams located?
(a) R. Satluj (b) R. Damodar
(c) R. Mahanadi (d) R. Krishna
Ans. (b)
Q.18. Which of the following river projects or groups of river projects provide
hydroelectricity
to the industries of Maharasthra?
(a) Pravara Project and Koyna
Project
(b) Hirakud Project
(c) Nagarjuna Sagar Project
and Tungabhadra Project
(d) Ghatprabha Project and
Mettur Project
Ans. (a)
Q.19. Which of the following dams are part of Chambal Project?
(a) Maithon, Panchet, Tilaiya,
Konar, Bokaro
(b) Pravara, Ramagundam
(c) Rana Pratap Sagar, Gandhi
Sagar (d) Sardar Sarovar Dam
Ans. (c)
Q.20. Which of the following environmental damages are not induced due to
multipurpose
projects?
(a) Water-borne diseases and
pests
(b) Pollution resulting from
excessive use of water
(c) Earthquakes (d) Volcanic
activity
Ans. (d)
Q.21. In which of the following areas are ‘guls’ and ‘kuls’ used to channel
water for
agriculture?
(a) Deccan Plateau (b) Deserts
of Rajasthan
(c) Western Himalayas (d)
Ganga Plains
Ans. (c)
Q.22. Due to which of the following reasons are rooftop rainwater harvesting
commonly
practised, particularly in Rajasthan?
(a) To store water for
irrigation (b) To keep the house cool
(c) To store drinking water
(d) To clean the rooftops
Ans. (c)
Q.23. Which of the following structures are known as ‘tankas’?
(a) Underground tanks for
storing rainwater harvested from roof tops for drinking purpose
(b) Tanks constructed on
rooftops for storing rainwater
(c) Tanks constructed in
agricultural fields to store rainwater
(d) Tanks constructed to store
floodwater
Ans. (a)
Q.24. In which of the following states is the bamboo-drip irrigation system
prevalent?
(a) Rajasthan (b) Himachal
Pradesh (c) West Bengal (d) Meghalaya
Ans. (d)
PREVIOUS YEARS’ QUESTIONS
Q.1. Bamboo drip irrigation is prevalent in which of the following states?
(a) Rajasthan (b) Meghalaya
(c) Karnataka (d) Madhya Pradesh
Ans.
(b)
Q.2. Who among the following proclaimed dams as the temple of modern India?
(a) Rajendra Prasad (b)
Jawaharlal Nehru (c) Sardar Patel (d) Mahtama Gandhi
Ans.
(b)
Q.3. Roof tap rainwater harvesting system in Rajasthan is known as :
(a) Guls (b) Kuls (c) Tankas
(d) Baobs
Ans.
(c)
Q.4. Which one of the following is not an adverse effect of dams?
(a) Interstate water disputes
(b) Excessive sedimentation of Reservoir
(c) Displacement of population
(d) Flood control
Ans.
(d)
Q.5. Which of the following is not a method of water haresting used in
Rajasthan?
(a) Johads (b) Khadins (c) Guls (d)
Tankas
Ans.
(c)
Q.6. How much of the earth surface is covered with water?
(a) About 1/4 (b) About 1/2
(c) About 3/4 (d) About 2/3
Ans.
(c)
Q.7. On which one of the following rivers the Tehri Dam is being constructed?
(a) Bhagirathi (b) Yamuna (c)
Koshi (d) Sutlej
Ans.
(d)
Q.8. Which of the following rivers is not having any multipurpose river project?
(a) Satluj-Beas (b) Mahanadi (c) Narmada
(d) Yamuna
Ans.
(d)
Q.9. On which one of the following rivers Mettur dam is constructed?
(a) River Kaveri (b) River
Krishna (c) River Godavari (d) River Mahanadi
Ans.
(a)
Q.10. What is the contribution of hydroelectricity in the total generation of
electricity?
[2010 (T-1)]
(a) 52% (b) 42% (c) 32% (d)
22%
Ans.
(d)
Q.11. How much percent of the total volume of world’s water is estimated to
exist as fresh
water?
(a) 2.5 (b) 3.5 (c) 4.5 (d)
5.5
Ans.
(a)
Q.12. Which of the following is a source of Fresh water ?
(a) Precipitation (b) Surface
runoff (c) Groundwater (d) All the above
Ans.
(c)
Q.13. In which of the following regions, people built ‘Guls’ and ‘Kuls’ for
irrigation?
[2010 (T-1)]
(a) Northern Plains (b)
Western Himalayas (c) Coastal areas (d) None of these
Ans.
(b)
Q.14. Hirakud dam is built on which river?
(a) Chenab (b) Mahanadi (c)
Krishna (d) Satluj
Ans.
(b)
Q.15. In which one of the following states was rooftop rainwater harvesting
practised?
[2010 (T-1)]
(a) West Bengal (b) Haryana
(c) Rajasthan (d) Punjab
Ans.
(c)
Q.16. Salal Dam is built on which river?
(a) Chenab (b) Mahanadi (c)
Krishna (d) Satluj
Ans.
(a)
Q.17. Against the construction of which one of the following multipurpose
projects was the
Narmada Bachao Andolan launched?
(a) Sardar Sarovar (b) Bhakra
Nangal (c) Rihand (d) Tehri
Ans.
(a)
Q.18. Tanka, a rainwater harvesting technique, is associated with which of the
following states?
(a) Tamil Nadu (b) West Himalayas (c)
Gujarat (d) Rajasthan
Ans.
(d)
Q.19. Which of the following is not one of the reasons for criticism of
multipurpose river valley
projects?
(a) They create a rockier
stream bed
(b) They create poorer
habitats for the river’s acquatic life
(c) The reservoirs created in
the floodplain submerge vegetation
(d) They help in generation of
hydroelectricity
Ans.
(d)
Q.20. Large scale irrigation has led to :
(i) Changed cropping pattern
in many regions
(ii) Increased salinisation of
soil
(iii) Average reduction in
crop production
(iv) Increasing gap between
the rich and the poor farmers
(a) i, ii, iii (b) i, iii, iv
(c) i, ii, iv (d) i, iv, iii
Ans.
(c)
Q.21. What percentage of the total volume of world’s water is estimated to exist
as oceans?
(a) 94.5% (b) 95.5% (c) 96.5% (d) 97.5%
Ans.
(c)
Q.22. Nagarjuna Sagar Dam is built on which river?
(a) Clenab (b) Mahanadi (c)
Krishna (d) Satluj
Ans.
(c)
Q.23. Sardar Sarovar Dam is constructed on :
(a) River Krishna (b) River
Mahanadi (c) River Cauvery (d) River Narmada
Ans.
(d)
Q.24. In which one of the following states palar pani is considered the purest
form of natural
water?
(a) Gujarat (b) Rajasthan (c)
Madhya Pradesh (d) Chhattisgarh
Ans.
(b)
Q.25. Which of the following is not the cause of water scarcity?
(a) Rapid growth of population
(b) Uneven distribution of water resources
(c) Construction of dams and
reserves (d) Increase in demand
Ans.
(c)
Q.26. Which state has made rooftop rainwater harvesting structure compulsory to
all the
houses across the state?
(a) Kerala (b) Karnataka (c)
Tamil Nadu (d) Andhra Pradesh
Ans.
(c)
Q.27. On which of the following rivers is Koyena dam built?
(a) Krishna (b) Kaveri (c)
Ganga (d) Mahanadi
Ans.
(a)
Q.28. Which of these is the major source of fresh water in India?
(a) Ground water (b) Ocean
water (c) Tanks (d) Waterfalls
Ans.
(a)
SHORT ANSWER TYPE QUESTIONS
Q.1. Why has the water shortage problem aggravated in post-independence India?
Ans.
Intensive industrialisation and urbanisation witnessed in post-independence
India have
significantly contributed to
the exploitation of available freshwater resources. Industries
require huge supply of water
for production, cooling of machineries and for power supply
in form of hydroelectricity.
Ever increasing urban centers with large and dense population
and urban lifestyles have
increased the domestic water requirement and power requirement.
Individual groundwater pumping
devices in housing complexes of big cities have aggravated
the problem of depletion of
water resources. Agricultural progress in the post-independence
era has also led to water
scarcity. Irrigation in different forms to increase agricultural
production exploits the
available surface and groundwater sources excessively. As a result
of the above mentioned reasons
the water shortage problem has aggravated in post-independence
India.
Q.2. Why should we conserve and manage our water resources? How can we control
overexploitation
and mismanagement of water resources? State any two points that should be
kept in mind for efficient management of water.
Ans.
We
should conserve and manage our water resouces to safeguard ourselves from health
hazards, to ensure food
security as well as for continuation of our livelihood and productive
activities. Taking into
consideration the problem of water scarcity and decreasing freshwater
resources, the need of the
hour is to conserve and manage our water resources.
Over-exploitation and
mismanagement of water resources can be controlled through
conservation and management of
water resources. Conservation can also prevent degradation
of our natural ecosystem as
well as control the ecological crisis that may arise due its scarcity.
Two points that should be kept
in mind for efficient management of water are :
(i) Prevention of water
pollution, so that available water sources are not rendered unusable.
(ii) Integrated Water Resource
Management should develop water saving technology and
recycling and reuse of water.
Rainwater harvesting should be
promoted.
Q.3. Mention a negative effect of irrigation? How can irrigation transform the
social
landscape?
Ans.
Irrigation has changed the cropping pattern of many regions with farmers
shifting to cultivation
of water intensive and
commercial crops. This has great ecological consequences. It leads to
water logging and consequent
salinisation of the soil. This is a negative effect of irrigation.
As rich farmers have better
access to irrigation they have earned more money due to the
production of commercial
crops. On the other hand, the landless poor who couldn’t avail of
its benefit, became poorer.
Thus, irrigation has transformed the social landscape by increasing
the social gap between rich
landowners and the landless poor farmers.
Q.4. Give examples of traditional water harvesting system prevalent in various
parts of India.
Ans.
Traditional water harvesting system prevalent in various parts of the India
include the
following methods :
(i) Diversion channels like
‘guls’ and ‘kuls’ of Western Himalayas are built in hilly and
mountain areas for irrigating
agricultural fields.
(ii) In hilly areas of
Meghalya, bamboo-drip irrigation system taps stream and spring water.
(iii) Inundation channels are
constructed to irrigate agricultural fields in the floodplains of
Bengal.
(iv) In the arid regions of
Rajasthan agricultural fields were converted into rainfed storage
structures locally known as
‘Khadins’ in Jaisalmer and ‘Johads’ in other parts of
Rajasthan. These structures
allowed the water to stand and moisten the soil.
(v) Rooftop rainwater
harvesting was commonly practised to store drinking water particularly
in Rajasthan. In the semi-arid
and arid regions of Rajasthan, particularly in Bikaner,
Phalodi and Barmer, almost all
the houses traditionally had underground ‘tankas’ or
‘tanks’ for storing drinking
water.
Q.5. What is rainwater harvesting? State the objectives of rainwater harvesting.
Ans.
Rainwater harvesting is an efficient method of water conservation and
management. The
techniques of collecting and
storing rainwater directly or recharging it into the ground through
artificial means to improve
groundwater storage is called rainwater harvesting. It includes
traditional methods like (i)
conversion of agricultural fields into rainfed storage structures
locally known as ‘Khadins’ and
‘Johads’ in Rajasthan, (ii) rooftop rainwater harvesting to store
drinking water in tanks or
sumps for direct usage and to recharge and use groundwater for
household purposes through
abandoned wells or check dams, or through handpumps during dry
season.
Rainwater harvesting is very
simple, practical and cost effective and can be easily conducted
by individuals to solve their
water problem.
The objectives of rainwater
harvesting are :
(i) To prevent wastage and
pollution of the monsoon rains.
(ii) To reduce runoff and
control the flooding of roads.
(iii) To recharge and improve
the quality of groundwater storage and raise water table.
(iv) The meet the demands of
domestic water requirement during dry season.
(v) To solve problem of
drinking water shortage especially in regions receiving less rainfall.
PREVIOUS YEARS’ QUESTIONS
Q.1. What is rainwater harvesting? Explain any two different methods of
rainwater
harvesting in different regions of India.
Ans.
Rainwater harvesting is a system in which rain water is collected through
various techniques
and then collected water is
used in many ways.
(i) Hill region - In
hilly region people built diversion channels like the ‘‘guls’’ or ‘‘kuls’’ in
the western Himalayas for
agriculture. With these channel rainwater is used in meaningful
ways.
(ii) Arid region - In
Rajasthan almost all houses had underground tanks. These tanks were
part of well developed rooftop
rainwater harvesting system. They were connected to the
sloping roof of the houses
through a pipe. Rain falling on the rooftops would travel down
the pipe and get stored in
these underground ‘tankas’.
Q.2. What is a multipurpose river valley project? Give any four objectives of
the multipurpose
river valley project.
Ans.
The
multipurpose river valley project is a river project in which a dam is
constructed on the
river and stored water is then
used in a number of for like irrigation, power generetion etc.
Four objectives of
multipurpose projects are :—
(i) To check floods by
regulating flow of water.
(ii) To generate hydropower
for our industries and homes.
(iii) To provide irrigation
facilities. This helps in increasing agricultured productivity and
bringing more area under
cultivation.
(iv) To check soil Erosion.
Q.3. Discuss how rainwater harvesting in semi-arid regions of Rajasthan is
carried out.
Ans.
Rain water harvesting in semi-arid region of Rajasthan is carried out in the
following ways :-
In Bikaner, Phalodi and
Barmer, almost all the houses traditionally had underground tanks or
‘‘tankas’’ for storing
drinking water. 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 metres long and 2.44 metres wide. The
tankas were part of the
well-developed rooftop rainwater harvesting system and were built
inside the main house or the
courtyard. They 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’.
Q.4. Describe three traditional methods of rainwater harvesting practiced in
India.
Ans.
In
India traditionally rainwater harvesting is done in the following ways :—
(i) In hilly regions people
built diversion channels like the guls or kuls for agriculture.
(ii) In Rajasthan rooftop
rainwater harvesting is practiced.
(iii) In Bengal people built
inundation channels to irrigate their fields.
(iv) In arid and semi-arid
regions people convert their agricultural fields into rain fed storage
structures.
Q.5. Give three reasons for water scarcity in post-independence India
Ans.
Three reasons for water scarcity in India are :–
(i) Post-independence India
has witnessed intensive industrialization and urbanization which
increased water demand.
(ii) Large urban centers with
large and dense population and urban lifestyles have only added
to water requirement.
(iii) Population explosion
after independence led to overexploitation of underground water for
irrigation.
Q.6. ‘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.
Water scarcity is due to the following causes :—
(i) Water availability varies
over space and time mainly due to the variation in seasonal and
annual precipitation.
(ii) Rapid urbanization is
another factor for water scarcity.
(iii) Rapid increase in
population that demand more and more water.
(iv) Industrialization is
another cause, large industrial houses are using more and more water,
they also require more water
to generate electricity.
(v) Rising income levels also
create more demand for water.
(vi) 96.5 per cent of the
total volume of world’s water is estimated to exist as oceans and only
2.5 per cent as fresh water.
Nearly 70 per cent of this freshwater occurs as ice sheets and
glaciers, while a litlle less
than 30 per cent is stored as groundwater in the world’s
aquifers.
Q.7. How have industrialization and urbanization aggravated water scarcity in
India?
Ans.
Industrialization and urbanization have aggravated water scarcity in India in
the following
ways :
(i) Large industrial houses
are exerting pressure on existing freshwater resources. Industries
apart from being heavy user of
water also require water power to run them.
(ii) Multiplying urban center
with large and dense population and urban lifestyles have not
only added to water and energy
requirement but further aggravated the problems. Water
resources are being
over-exploited.
Q.8. Why is the conservation and management of water resources important? Give
any three
reasons.
OR
Why is there an urgent need to conserve and manage our water resources? Give
three
reasons.
Ans.
The
conservation and proper management of water is necessary because of following
reasons:
(i) Growing population :-
As population is growing its need for water is also growing, so
it is necessary to properly
manage the availability of water.
(ii) Increasing
Urbanisation :- More and more people are moving to cities where need of
water is growing. On the other
hand, cities are overexploiting and polluting water
resources, so there is need to
conserve water.
(iii) Due to
industrialisation also water is being overexploited. So, without proper
conservation it would be
difficult to survive.
Q.9. Explain any three disadvantages of multipurpose projects.
Ans.
Three disadvantages of multipurpose projects are :-
(i) A large area is submerged
with water causing destruction of wildlife and forests.
(ii) A large number of people
living in the affected areas are displaced, so their rehabilitation
remains a problem.
(iii) Aquatic life and natural
course of rivers get affected. Multipurpose projects had to
destruction of flora and
fauna.
Q.10. Why are different water harvesting systems considered a viable alternative
both socio -
economically and environmentally in a country like India?
Ans.
No
single method can be applicable everywhere. It is true in rain case of water
harvesting
system too, as geographically
there are different regions. Different regions have different
methods.
(i) In Hilly region :-
Through kuls or guls it is very easy to divert water for irrigation. It is
a low cost method.
(ii) In Arid region :-
Like in Rajasthan rainwater is collected on roofs, then piped into ground
storage system. That method is
also economical, needing no extra effort.
(iii) In villages agricultural
fields are converted into ponds where rainwater is collected. All
these methods are very easy
and viable
Q.11. How far have the multipurpose projects been able to achieve their purpose
for which they
were made? Explain.
Ans.
To
some extent multipurpose river valley projects have been able to achieve their
purpose.
Irrigation has increased,
power generation is a classic example of their success. But there are
some concerns too.
(i) They have obstructed the
natural flow of rivers causing destruction of habitat aquatic
life.
(ii) People have also been
affected as their habitat too have been submerged. It leads to socioeconomic
proplems of big magnitude as
lakhs of people are displaced.
(iii) This has led to huge
destruction of flora and fauna, forests and biodiversity.
Q.12. Why is the need for water increasing day by day? Explain three reasons.
Ans.
(i)
Rapid industrialisation and urbanization have led to greater demand for water.
Industries
need water for various
purposes.
(ii) Large population means
more water is needed for domestic use and for agriculture to
produce more food.
(iii) Multiplying urban
centres with large and dense population and urban life-styles have led
to greater need for water.
Q.13. Give an account of any three hydraulic structures of ancient India.
Ans.
(i)
During the period of Chandragupta Maurya dams, lakes and irrigation systems were
extensively built.
(ii) In the 11th century,
Bhopal lake, one of the largest artificial lakes of its time was built.
(iii) In the first century
B.C. Sringaverpur near Allahabad had large and complex water
harvesting system chenneling
the water of the Ganga.
Q.14. ‘Large multi-purpose projects also lead to land degradation.’ Explain.
Ans.
Regulating and damaging of rivers affect their natural flow causing poor
sediment flow and
excessive sedimentation at the
bottom of reservoir. Large reservoirs submerge large tracts of
forests, flora and fauna. They
also submerge soil leading to its decomposition over a period of time.
LONG ANSWER TYPE QUESTIONS
Q.1. Multipurpose river projects are referred as the ‘temples of modern India.’
Elucidate.
OR
Why did Jawaharlal Nehru proudly proclaim the dams as the temples of modern
India?
Ans.
Multipurpose River Projects were launched after Independence with the approach
of integrated
water resource management. The
objective was to provide multifarious benefits that would
lead to the development and
progress of the nation, overcoming the handicap of its colonial
past. Jawaharlal Nehru had
proudly proclaimed the present-day dams or multipurpose projects
as ‘temples of modern India’.
The reason behind this was that these projects integrate the
development of agriculture
with rapid industrialization and lead to the progress of both the
village and urban economy.
The benefits provided by
Multipurpose Projects include :
(i) Providing water to those
areas which suffer from water scarcity.
(ii) Irrigation of
agricultural fields during dry season as well as in regions of scanty or
inadequate rainfall.
This helps in increasing
agricultural productivity and bringing more area under cultivation.
(iii) Flood control by
regulating flow of water.
(iv) Water supply for domestic
and industrial purposes.
(v) Generation of
hydroelectricity for our industries and homes.
(vi) Inland navigation for the
purpose of transport and trade.
(vii) Fish breeding.
(viii) Recreational
facilities.
(ix) Soil conservation through
afforestation.
As a result of these benefits
that lead to all round development of the nation, the
multipurpose projects are
termed as ‘temples of modern India.’
Q.2. In recent years, multipurpose projects and large dams have come under great
scrutiny
and opposition. Explain why.
OR
What objections have been raised against multipurpose river valley projects?
Explain
any three.
Ans.
In
recent years, multipurpose 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 and lead to sedimentation and
rockier stream beds which
become poorer habitats for aquatic life.
(ii) Fragmentation of the
river, its diversion and barricading due to building of dams affect
migration and spawning of
aquatic life.
(iii) The reservoirs that are
created on the floodplain overflow and submerge the existing
vegetation and soil and
consequently lead to their decomposition and land degradation.
(iv) Ironically, the dams that
were constructed with the objective of flood control have
triggered floods due to
sedimentation in the reservoir and release of excess water during
heavy rains.
(v) The primary cause of
resistance to some multipurpose projects like the ‘Narmada Bachao
Andolan’ and the ‘Tehri Dam
Andolan’ by activists of social and ecological movements
is large scale displacement of
local communities who lose their livelihood when ousted
from their land for the
projects.
(vi) Landowners and large
farmers, industrialists and a few urban centres are benefitted while
the more numerous local people
who give up their land for the projects hardly receive any
benefit. This widens the
social gap between the rich and the poor and leads to social
tensions.
(vii) Interstate water
disputes with regard to sharing the costs and benefits of multi-purpose
projects are leading to
tension between states, e.g. Kaveri-Godavari dispute, Sabarmati
water dispute.
(viii) It has also been
observed that multipurpose projects induced earthquakes, caused water
borne-diseases and pests, and
led to pollution resulting from excessive use of water.
Q.3. What are interstate water disputes? Why are such issues raised? Give
examples of interstate
water disputes.
Ans.
Tension created between two or more states regarding sharing of river water
mainly due to
construction of multipurpose
projects is termed as interstate water dispute. Interstate water
disputes arise between states
regarding sharing of the costs and benefits of the multipurpose
projects. When a river flows
through two or more states, damming at one state may affect the
flow and volume in another
state. If the flow is not regulated, one state may derive multiple
benefits from the river, and
another state may suffer leading to interstate disputes.
Interstate water disputes :
(i) The Krishna-Godavari
dispute is due to the objections raised by Karnataka and Andhra
Pradesh regarding the
diversion of more water at Koyna, a tributary of river Krishna, by
Maharashtra government for the
Koyna hydroelectric project. The construction of the
multipurpose project would
reduce downstream flow in their states with adverse
consequences for their
agriculture and industry.
(ii) The Kaveri water dispute
between Karnataka and Tamil Nadu regarding sharing of the
water of Kaveri river.
(iii) Narmada River water
dispute involving Rajasthan, Madhya Pradesh, Gujarat,
Maharashtra and (iv) Ravi-Beas
water dispute between Punjab and Haryana and
(v)
Mandovi-Mahadayi-Vansadhara and dispute between Goa, Karnataka and Andhra
Pradesh and Orissa.
Q.4. Write about the rooftop rainwater harvesting system prevalent in Meghalaya.
How is the
bamboo drip irrigation system employed for water harvesting in Meghalaya.
Ans.
Rooftop rainwater harvesting is the most common practice in Shillong, Meghalaya.
Shillong,
the capital of Meghalaya, is
situated only at a distance of 55 km from Mawsynram, the place
receiving highest rainfall in
the world. Yet, it faces acute water shortage as it is located in the
rainshadow area on the leeward
side of Khasi hills. So, nearly every household has rainwater
harvesting structure to tap
whatever amount of rainfall is received by the area for use during
dry periods. Nearly 15 to 25
percent of the total water requirement of the households comes
from rooftop rainwater
harvesting.
The Bamboo-drip irrigation
system prevalent in Meghalaya is 200-years old system of tapping
stream and spring water by
using bamboo pipes. Bamboo grows naturally in plenty in the
region. Hence, bamboos are
used instead of pipes for collection of water free of cost. Bamboo
pipes are used to divert water
from perennial springs on the hilltops to the lower reaches by
gravity. The channel sections,
made of bamboo, divert water to the plant site where it is
distributed into branches,
again made and laid out with different forms of bamboo pipes. The
flow of water into the pipes
is controlled by manipulating the pipe positions. The last channel
section enables water to be
dropped near the roots of the plant.
About 18-20 litres of water
enters the bomboo pipe system, gets transported over hundreds of
metres, and finally reduces to
20-80 drops per minute at the site of the plant.
Q.5. An area or region may have ample water resources but still face water
scarcity. Explain
why such circumstances arise.
Ans.
(i)
Water scarcity in most of the cities are an outcome of dense and growing
population. The
multiplying urban centres and
urban lifestyles of the huge population have not only added
to water and power
requirements but have also aggravated the problem by over-exploiting
available groundwater
resources.
(ii) A large and growing
population results in greater demands of water and consequently
unequal access to it,
especially in rural areas.
(iii) More water is required
for domestic use by the multiplying population. Over and above,
available water resources are
over- exploited for expanding irrigation and dry season
farming to facilitate higher
foodgrain production. Over-irrigation may lead to falling
groundwater levels, adversely
affecting water availability and food security of the people.
(iv) Ever-increasing number of
industries with their heavy consumption of water and
hydroelectricity have placed
undue pressure on the existing freshwater resources.
(v) Another situation of water
scarcity arises when the available water resources are rendered
unusable due to pollution by
discharge of effluents from industries, use of pesticides and
chemical fertilisers in
agriculture and due to dumping of domestic wastes.
Q.6. Identify the reasons (any three) for water scarcity specially, in
metropolitan towns.
Suggest one measure that in your opinion can lead to a more equitable
distribution of
available water supply.
Ans.
Metropolitan towns are characterised by large and dense population and intensive
urbanisation
as well as industrialisation.
The fast development demands excess use of water leading to
water scarcity. The main
reasons for water scarcity in metropolitan towns are as follows :
(i) The dense population with
urban lifestyles not only consumes more water and energy for
daily domestic requirements
but has further aggravated the problem by over-exploiting the
available groundwater
resource.
Housing societies and colonies
in the metropolitan cities have their own groundwater
pumping devices to meet their
water needs. As such, the groundwater level in the cities
has been adversely affected
due to over-exploitation.
(ii) Industries and
multinational corporations in the metropolitan cities have made the water
situation worse. They have
exerted pressure on existing freshwater resources due to heavy
consumption of water and
hydroelectricity.
(iii) Water pollution due to
discharge of domestic and industrial wastes into water bodies leads
to water scarcity.
A more equitable distribution
of available water supply throughout the country can be
achieved through linking of
the river systems of India. This can distribute the water in the
various river basins from
areas of surplus to areas with deficient water resources.
Q.7. Water is available in abundance in India but even then scarcity of water is
experienced
in major parts of the country. Explain with four examples.
Ans.
India receives nearly 4 per cent of the global precipitation. The total
renewable water resources
of India are estimated at
1,897 sq km per annum. Inspite of this fact that water is available in
abundance in India, scarcity
of water is experienced in major parts of the country. At present
India ranks 133rd in the world
in terms of water availability per person per annum. It is
predicted that by 2025, large
parts of India will join countries or regions having absolute water
scarcity.
Geographically, some parts of
India like the desert region of Rajasthan receive low rainfall and
are drought-prone. Thus, water
shortage is a common and regular problem of such regions.
The metropolitan cities of
India like Mumbai and Kolkata face acute water shortage on account
of large and dense populations
and their urban lifestyles requiring more water and power
consumption. The multistoried
buildings and housing complexes or colonies have their own
groundwater pumping devices
which lead to over-exploitation and depletion leading to water
scarcity.
In the industrial areas of
Uttar Pradesh, National Capital Region, Bihar etc. water pollution due
to discharge of effluents and
industrial wastes and chemicals has turned big rivers like Ganga
and Yamuna into toxic streams.
Though freshwater resources are present in sufficient
quantities, it is unfit and
hazardous for human use.
In agriculturally advanced
regions of India like Punjab, Haryana and Western Uttar Pradesh,
to facilitate higher food
grain production for our growing population, water resources are being
over-exploited to expand
irrigated areas and dry-season agriculture. Over-irrigation in these
areas have adversely affected
water-availability.
Q.8. How have intensive industrialisation and urbanisation passed a great
pressure on existing
freshwater resources in India? Explain with two examples for each.
Ans.
Intensive industrialisation and urbanisation in the post-independence period
have exerted great
pressure on existing
freshwater resources of India. The following examples further explain
their effects on the fragile
water resources of India.
Effects of industralisation.
Industries like cotton textile mills of Maharashtra, jute textile
mills of Hooghly basin in West
Bengal and all the iron and steel plants in the Damodar Valley
region and other parts of the
country are heavy users of water and require large supply of
hydroelectricity. The existing
freshwater sources of these regions are over-exploited as a result.
Discharge of industrial
effluents and dumping of industrial wastes and chemicals have turned
big rivers like Ganga and
Yamuna into toxic streams unfit and hazardous for human use.
Pollution of the freshwater
resources have led to water scarcity.
Effects of urbanisation.
The
metropolitan cities of India like Mumbai and Kolkata face acute
water shortage on account of
large and dense population and their urban lifestyles requiring
more water and power
consumption.
Housing societies and colonies
and multistoreyed buildings in the cities have their own
groundwater pumping devices
which lead to over-exploitation and depletion of the fragile
water resources.