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Water Resources – Class 12 Geography notes, important questions and MCQs

NCERT Class 12 Geography, chapter 12. Notes, key terms, important questions with answers and MCQs.

Chapter overview

India has about 4% of the world's water resources but about 18% of its population. Water resources include surface water (rivers, lakes, ponds) and groundwater. Agriculture uses most of the water, followed by domestic and industrial use. Water scarcity, pollution and declining groundwater levels are serious problems, so conservation methods such as rainwater harvesting, watershed management and efficient irrigation are essential.

Water resources and use

Surface water resources come mainly from rivers; the Ganga, Brahmaputra and Barak basins contain a large share of India's surface water.
Groundwater is heavily used in the north-western plains and parts of south India; overexploitation in Punjab, Haryana, Rajasthan and Tamil Nadu has lowered water tables.
Agriculture accounts for the largest share of water use, mainly for irrigation; demand from domestic and industrial sectors is increasing with urbanisation and industrialisation.

Problems and conservation

Water quality is deteriorating due to industrial effluents, urban sewage and agricultural chemicals; programmes such as the National Mission for Clean Ganga (Namami Gange) aim to clean rivers.
Conservation measures include rainwater harvesting, watershed development (such as Haryali, Neeru-Meeru in Andhra Pradesh and Arvary Pani Sansad in Rajasthan), recycling and reuse of water, and drip and sprinkler irrigation.
The National Water Policy emphasises water allocation priorities, conservation and participatory management; the Jal Shakti Abhiyan promotes water conservation.

Key terms

Groundwater: water stored beneath the Earth's surface in soil and rock
Rainwater harvesting: collecting and storing rainwater for later use
Watershed management: conserving and managing land and water resources in a drainage area
Drip irrigation: supplying water drop by drop to plant roots
Water scarcity: shortage of water relative to demand

Important questions with answers

What is rainwater harvesting?2 marks

Rainwater harvesting is the method of capturing and storing rainwater from rooftops, open areas and catchments in tanks, pits or wells for later use. It helps recharge groundwater, reduces runoff and provides water during dry periods.

What are the causes of water pollution in India?3 marks

Water is polluted by the discharge of untreated industrial effluents, urban sewage, agricultural runoff containing fertilisers and pesticides, solid waste dumping, and religious and cultural activities near rivers. This affects human health and aquatic life.

Why is water conservation necessary in India? Explain the methods.5 marks

Water conservation is necessary because India's water resources are limited compared to its large population and growing demand. Rainfall is seasonal and unevenly distributed, many regions face scarcity, groundwater is being overexploited faster than it is recharged, and pollution makes much water unfit for use. Demand from agriculture, households and industries is rising with population growth, urbanisation and industrialisation. Several methods can conserve water. Rainwater harvesting from rooftops and open areas stores water and recharges groundwater, and has been made compulsory for buildings in some cities. Watershed management conserves soil and water in a drainage area through check dams, contour bunding, afforestation and community participation; successful examples include Haryali, Neeru-Meeru in Andhra Pradesh and Arvary Pani Sansad in Rajasthan. Efficient irrigation methods such as drip and sprinkler irrigation reduce wastage compared to flood irrigation. Recycling and reuse of wastewater for industry, gardening and flushing reduce demand for fresh water. Preventing pollution through sewage treatment, controlling industrial effluents and programmes like Namami Gange improves water quality. Public awareness, pricing and the National Water Policy also promote conservation.

Quick revision

Surface water and groundwater.
Agriculture uses most water.
Pollution; Namami Gange.
Conservation: rainwater harvesting, watershed management, efficient irrigation.

Exam tips

List three causes and three solutions of water scarcity.
Remember: India has about 4% of world water and about 18% of world population.

Practice MCQs

The largest user of water in India is
1. agriculture
2. industry
3. domestic sector
4. power plants only
Show answer
Answer: (a) agriculture. Irrigation needs most water.
Collecting and storing rainwater for later use is called
1. irrigation
2. desalination
3. rainwater harvesting
4. evaporation
Show answer
Answer: (c) rainwater harvesting. It recharges groundwater.
Supplying water drop by drop to plant roots is
1. flood irrigation
2. drip irrigation
3. canal irrigation
4. tank irrigation
Show answer
Answer: (b) drip irrigation. It saves water.
Overexploitation of groundwater is a serious problem in
1. Meghalaya
2. Mizoram
3. Punjab and Haryana
4. Andaman Islands
Show answer
Answer: (c) Punjab and Haryana. Tube wells are used heavily.
The programme to clean the Ganga is called
1. Namami Gange
2. Haryali
3. Neeru-Meeru
4. Arvary Pani Sansad
Show answer
Answer: (a) Namami Gange. It aims to reduce pollution.
Neeru-Meeru is a watershed programme of
1. Rajasthan
2. Punjab
3. Andhra Pradesh
4. Bihar
Show answer
Answer: (c) Andhra Pradesh. It means 'water and you'.
Why is groundwater declining in many parts of India
1. low use of tube wells
2. excess rainfall
3. extraction exceeds recharge, especially for irrigation
4. no agriculture
Show answer
Answer: (c) extraction exceeds recharge, especially for irrigation. Overuse lowers water tables.
Which is the most important reason to promote watershed management
1. it increases soil erosion
2. it conserves soil and water and improves livelihoods in a drainage area
3. it stops all farming
4. it is only for cities
Show answer
Answer: (b) it conserves soil and water and improves livelihoods in a drainage area. It integrates land and water conservation.

All chapters of Class 12 Geography

Written by Kundali IQ from standard, well-established facts to help with revision. This is not an official NCERT publication; always read your textbook too.