→ Three-fourth of the earth’s surface is covered with water but only a small proportion of it is freshwater that can be put to use.

• Freshwater is mainly obtained from precipitation, surface run-off and groundwater.
• Groundwater isTieing continually renewed and recharged through the hydrological cycle.
• It is predicted that by 2025 nearly two billion people will live in absolute water scarcity.

→ Water Scarcity7 and the Need for Water Conservation and Management

• The availability of water resources varies over time and space because of variations in seasonal and annual precipitation.
• 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 due to outcome of large and growing population and consequent gfeater demands for water and unequal access to it.
• This means higher food grain production.
• This leads to exploitation of water resources to expand irrigated areas and dry-season agriculture. .
• Most farmers have their own wells and tube wells in their farms for irrigation to increase their produce. This may reduce the level of groundwater which may adversely affect the availability of water and food security of the people.
• The existing freshwater resources are under tremendous pressure from the ever- increasing number of industries, multiplying urban centres and urban lifestyles.
• Scarcity of water may also be due to bad quality of water. Water may be polluted by domestic and industrial wastes, chemicals, pesticides and fertilisers used in agriculture, thus, making it hazardous for human use.
• It is necessary to conserve and manage water resources to safeguard ourselves from health hazards, to ensure food security, continuation of our livelihoods and productive activities and to prevent degradation of natural ecosystems.
• Overexploitation and mismanagement of water resources will deplete this resource and cause ecological crisis which may affect our lives deeply.

→ Multi-Purpose River Projects and Integrated Water Resources Management

• Archaeological and historical records show that in the ancient times construction of sophisticated hydraulic structures, such as dams built of stone rubble, reservoirs, lakes, embankments and canals for irrigation.
• Traditionally dams were built to impound rivers and rainwater that could be used later for irrigating agricultural fields. These days dams are constructed not only for irrigation, but also for electricity generation, flood control, domestic and industrial water supply, fish breeding, inland navigation and recreation. They are now known as multi¬purpose river projects.
• The multi-purpose projects were launched after Independence with their integrated water resource management approach with aim of leading the nation to development and progress. Jawaharlal Nehru proclaimed dams as the‘temples of modem India’.
• However, multi-purpose projects have their disadvantages. These projects lead to sedimentation, which obstructs the natural flow, resulting in rockier stream beds; make it difficult for aquatic fauna to migrate, especially for spawning; submerge the floodplains and vegetation, leading to decomposition of soil over a period of time.
• Multi-purpose projects also lead to large- scale displacement of local communities, tearing them off of their livelihood and resources. Social movements like Narmada Bachao Andolan and Tehri Dam Andolan resist these projects.
• Irrigation has changed the cropping pattern as farmers have shifted to water-intensive cropping causing salinisation of soil.
• Inter-state water disputes have increased.
• These dams have triggered floods due to sedimentation in the reservoif, induced earthquakes, and caused land degradation, water-borne diseases, pests and pollution due to excessive use of water.

→ Rainwater Harvesting:

• Water harvesting is a viable alternative, both socio-economically and environmentally as compared to the multi-purpose projects.
• In ancient India, there had been sophisticated hydraulic systems of rainwater harvesting.
• People had in-depth knowledge of rainfall regimes, wide range of techniques to harvest rainwater, river water, flood water and recharge the groundwater sources, keeping in mind the ecological conditions and their water needs.
• In the mountainous regions, people built channels like ‘kuhls’ or ‘guls’ for agriculture. In Bengal, people developed inundation channels to irrigate their fields.
• In the arid and semi-arid regions ofRajasthan, farmers converted their agricultural fields into rain-fed storage structures that allowed the water to stand and moisten the soil like the ‘khadins’ in Jaisalmer and ‘Johads’ in other parts of Rajasthan. In Bengal, people carved out inundation channels to irrigate their fields.
• In Bikaner, Phalodi and Banner, Rajasthan, people had well-structured rooftop rainwater harvesting system which were connected with underground tanks or tankas for storing water also called ‘Palar pani’.
• This water was used during the dry season when there was scarcity of water.
• Today, in western Rajasthan plenty of water is available due to the perennial Indira Gandhi Canal.
• Gendathur, a remote backward village of Mysuru, Karnataka has earned the rare distinction of being rich in rainwater by practising rooftop rainwater harvesting system.
• Tamil Nadu is the first state to make rooftop rainwater harvesting compulsory to all houses across the state. There are legal provisions to punish the defaulters.
• Shillong in Meghalaya, 200-year old bamboo drip irrigation system is followed for irrigating plants.

JAC Class 10 Social Science Notes

Multiple Choice Questions

Question 1.
How water is continually renewed and recharged?
(a) Nitrogen cycle
(b) Oxygen cycle
(c) Carbon cycle
(d) Hydrological cycle
Answer:
(d) Hydrological cycle

Question 2.
How much of the earth’s surface is covered with water?
(a) one-fourth
(b) two-fourth
(c) three-fourth
(d) half
Answer:
(c) three-fourth

Question 3.
By what year is it predicted that large parts of India will have absolute water scarcity?
(a) 2025
(b) 2052
(c) 2022
(d) 2021
Answer:
(a) 2025

Question 4.
What is the contribution of hydroelectric power in total electricity produced?
(a) 2.5 per cent
(b) 4 per cent
(c) 80 per cent
(d) 22 per cent
Answer:
(d) 22 per cent

Question 5.
Which project in the Mahanadi basin integrates conservation of water with flood control?
(a) Sardar Sarovar Dam
(b) Nagarjuna Sagar Dam
(c) Hirakud Dam
(d) Tehri Dam
Answer:
(c) Hirakud Dam

Question 6.
Which river is known as the ‘river of sorrow’?
(a) Narmada
(b) Sutluj
(c) Godavari
(d) Damodar
Answer:
(d) Damodar

Question 7.
Sardar Sarovar Dam is associated with which movement?
(a) Chipko Movement
(b) Save Silent Valley
(c) Narmada Bachao Andolan
(d) Appiko Movement
Answer:
(c) Narmada Bachao Andolan

Question 8.
Which is considered the purest form of natural water?
(a) Pond water
(b) Reservoir water
(c) Palar pani
(d) River water
Answer:
(c) Palar pani

Question 9.
Nagarjuna Sagar Dam is built across which river?
(a) Godavari
(b) Kaveri
(c) Narmada
(d) Krishna
Answer:
(d) Krishna

Question 10.
Which is the first state in India which has made roof top rainwater harvesting structure compulsory to all houses across the state? >
(a) Kerala
(b) Maharashtra
(c) Karnataka
(d) Tamil Nadu
Answer:
(d) Tamil Nadu

Very Short Answer Type Questions

Question 1.
How is freshwater mainly obtained?
Answer:
Freshwater is mainly obtained from precipitation, surface run-off and ground water.

Question 2.
Why does the availability of water vary over time and space?
Answer:
Availability of water varies over time and space because of the variations in seasonal and annual precipitation.

Question 3.
What is the cause of water scarcity in most cases?
Answer:
The cause of water scarcity in most cases is due to over-exploitation, excessive use and unequal access to water among different social groups.

Question 4.
Name the largest artificial lake built in the 11th century.
Answer:
Bhopal Lake is one of the largest artificial lakes built in the 11th century.

Question 5.
What is the primary reason for the resistance to multi-purpose projects?
Answer:
Primary reason of resistance to the multi-purpose projects is large-scale displacement of local communities.

Question 6.
Who have benefited from multi¬purpose projects?
Answer:
The landowners, farmers, industrialists and few urban centres have benefited from multi-purpose projects.

Question 7.
What is the recent demand of Save Narmada Movement?
Answer:
Recently, Save Narmada Movement has re-focused the aim to enable poor citizens, especially the displaced people to get full rehabilitation facilities from the government.

Question 8.
How do people of hills and mountainous regions irrigate their fields?
Answer:
In hills and mountainous regions, people build diversion channels like the ‘guls’ or ‘kuls’ for agriculture.

Question 9.
Why is rooftop rainwater harvesting on the decline in Rajasthan?
Answer:
Rooftop rainwater harvesting is on the decline in western Rajasthan as plenty of water is available from the perennial Rajasthan Canal.

Question 10.
On a political map of India, mark the following dams.
(a) Salal
(b) BhakraNangal
(c) Tehri
(d) Rana Pratap Sagar
(f) Hirakud
(e) Sardar Sarovar
(g) Nagarjuna Sagar
(h) Tungabhadra

JAC Class 10 Social Science Important Questions

JAC Class 10th Geography Resource and Development Textbook Questions and Answers

Question 1.
Choose the right answer from the four alternatives given below.

(i) Based on the information given below classify each of the situation as ‘suffering from water scarcity’ or ‘not suffering from water scar
(a) Region with high annual rainfall.
(b) Region having high annual rainfall and large population.
(c) Region having high annual rainfall but water is highly polluted.
(d) Region having low rainfall and low population.
Answer:
(a) Not suffering,
(b) Not suffering
(c) suffering
(d) Not suffering

(ii) Which one of the following statements is not an argument in favour of multipurpose river projects?
(a) Multi-purpose projects bring water to those areas which suffer from water scarcity.
(b) Multi-purpose projects by regulating water flow helps to control Hoods.
(c) Multi-purpose projects lead to large scale’displacements and loss of livelihood.
(d) Multi-purpose projects generate electricity for our industries and our homes.
Answer:
Multi-purpose projects lead to large scale displacements and loss of livelihood.

(iii) Here are some false statements. Identify the mistakes and rewrite them correctly.
(a) Multiplying urban centres with large and dense population and urban lifestyles have helped in proper utilisation of water resources.

(b) Regulating and damming of rivers does not affect the river’s natural flow and its 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 drought.

(d) Today in Rajasthan, the practice of rooftop rainwater water harvesting has gained popularity despite high water availability due to the Indira Gandhi Canal.
Answer:
(a) Multiplying urban centres with large and dense population and urban lifestyles have caused the over exploitation of water resources.

(b) Regulating and damming of rivers affect their natural flow and causes the sediment to settle at the bottom of the reservoir.

(c) In Gujarat, the Sabarmati basin farmers were agitated when higher priority was given to water supply in urban areas, particularly during drought.

(d) Today in Rajasthan, the practice of rooftop rainwater harvesting is on the decline due to the Rajasthan canal.

Question 2.
Answer the following questions in about 30 words.
(a) Explain how water becomes a renewable resource.
(b) What is water scarcity and what are its main causes?
(c) Compare the advantages and disadvantages of multi-purpose river projects.
Answer:
(a) The freshwater is continually being renewed and recharged through the hydrological cycle. All water moves within the hydrological cycle ensuring that water is a renewable resources.
(b) The cause of water scarcity in most cases is due to over-exploitation, excessive use and unequal access to water among different social groups.

Question 3.
Answer the following questions in about 120 words.
(a) Discuss how rainwater harvesting in semi-arid regions of Rajasthan is carried out.
(b) Describe how modern adaptations of traditional rainwater harvesting methods are being carried out to conserve and store water.
Answer:
(a) In Bikaner, Phalodi and Barmer, Rajasthan, people had a well-structured rooftop rainwater harvesting system which were connected underground. tarikser tankas for storing drinking water, also called ‘Palar Pani’. This water was used during the dry season when there was scarcity of water.

(b) Tamil Nadu is the first state to make rooftop rainwater harvesting compulsory to all houses across the state. There are legal provisions to punish the defaulters. Shillong in Meghalaya, with acute water shortage practises rooftop rainwater harvesting. Shillong 200-year old bamboo drip irrigation system is followed for irrigating plants.

JAC Class 10 Social Science Solutions