NCERT Solutions for Class 12 Geography India: People and Economy Chapter 4: Water Resources

Chapter at a glance

Exercise Questions

Question 1 (i)

Which one of the following types describes water as a resource?
(a) Abiotic resource (b) Non-renewable Resources (c) Biotic Resource (d) Non-cyclic Resource

Answer

Water is a non-living (abiotic), cyclic and renewable resource.

1. Abiotic resource

Question 1 (ii)

Which one of the following south Indian states has the highest groundwater utilisation (in per cent) of its total ground water potential?
(a) Tamil Nadu (b) Karnataka (c) Andhra Pradesh (d) Kerala

Answer

Among south Indian states, Tamil Nadu has the highest groundwater utilisation relative to its potential (along with Punjab, Haryana and Rajasthan in the north).

1. Tamil Nadu

Question 1 (iii)

The highest proportion of the total water used in the country is in which one of the following sectors?
(a) Irrigation (b) Industries (c) Domestic use (d) None of the above

Answer

Irrigation accounts for the highest share — about 89% of surface water and 92% of groundwater utilisation.

1. Irrigation

Question 2 (i)

It is said that the water resources in India have been depleting very fast. Discuss the factors responsible for depletion of water resources?

Answer

1. Rapidly growing population – increasing demand for domestic use.
2. Expansion of irrigation – especially for water-intensive crops (paddy, sugarcane) and over-extraction of groundwater through tube-wells.
3. Industrialisation and urbanisation – increasing demand and pollution of water bodies by industrial effluents and sewage.
4. Pollution – makes available water unusable.
5. Wasteful use and poor management; deforestation reducing recharge.

Water resources are depleting due to population growth, expansion of irrigation and over-extraction of groundwater for water-intensive crops, industrialisation and urbanisation, pollution of rivers and lakes by effluents and sewage, wasteful use and reduced recharge due to deforestation.

Question 2 (ii)

What factors are responsible for the highest groundwater development in the states of Punjab, Haryana, and Tamil Nadu?

Answer

1. Intensive agriculture – Punjab and Haryana are Green Revolution states growing water-intensive crops like rice and wheat (and sugarcane in Tamil Nadu); multiple cropping requires heavy irrigation.
2. Tube-wells and wells – widespread use of tube-wells and pump sets, encouraged by free or subsidised electricity.
3. Limited or erratic surface water – Tamil Nadu has limited perennial rivers and depends on wells and tanks; low rainfall in parts of Punjab–Haryana.
4. Favourable aquifers in alluvial plains of Punjab and Haryana.

High groundwater development in Punjab, Haryana and Tamil Nadu results from intensive irrigated agriculture with water-intensive crops (rice, wheat, sugarcane), widespread tube-wells and pump sets aided by free or cheap electricity, limited or erratic surface water (especially in Tamil Nadu), and good alluvial aquifers.

Question 2 (iii)

Why the share of agricultural sector in total water used in the country is expected to decline?

Answer

The share of agriculture in total water use is expected to decline because of the growing demand from other sectors — rapid industrialisation and urbanisation will increase water use in industries, energy (thermal power) and domestic sectors. Also, efficient irrigation methods (drip and sprinkler irrigation) and water-saving practices will reduce agricultural water use.

Because growing industrialisation, urbanisation and power generation will increase the industrial and domestic demand for water, while efficient irrigation methods like drip and sprinkler irrigation will reduce agriculture’s use, so its share is expected to decline.

Question 2 (iv)

What can be possible impacts of consumption of contaminated/unclean water on the people?

Answer

Consumption of contaminated water causes water-borne diseases such as diarrhoea, cholera, typhoid, dysentery, jaundice/hepatitis and intestinal worms. Chemical contamination (fluoride, arsenic, nitrates, heavy metals) causes fluorosis, arsenicosis, skin diseases and cancer. It leads to high infant mortality, malnutrition, loss of working days and medical expenses.

Contaminated water causes water-borne diseases (diarrhoea, cholera, typhoid, dysentery, hepatitis, worms) and, through chemicals like fluoride and arsenic, fluorosis, skin disease and cancer — raising mortality, especially among children, and causing loss of work and medical costs.

Question 3 (i)

Discuss the availability of water resources in the country and factors that determine its spatial distribution?

Answer

Availability: 1. India accounts for about 2.45% of the world’s surface area, 4% of the world’s water resources and about 16% of the world’s population. 2. Total water available from precipitation in a year is about 4,000 cubic km. Availability from surface water and replenishable groundwater is 1,869 cubic km; of this, only about 60% can be put to beneficial use — total utilisable water resource is about 1,122 cubic km. 3. Surface water: there are four major sources — rivers, lakes, ponds and tanks. There are about 10,360 rivers and tributaries longer than 1.6 km. Mean annual flow in all river basins is about 1,869 cubic km; due to topographical, hydrological and other constraints, only about 690 cubic km (32%) of surface water can be utilised. 4. Groundwater: total replenishable groundwater is about 432 cubic km. The Ganga and Brahmaputra basins have about 46% of the total replenishable groundwater. The level of groundwater utilisation is high in the river basins of the north-western region and parts of south India. 5. Lagoons and backwaters – India has a vast coastline; states like Kerala, Odisha and West Bengal have vast surface water resources in lagoons and lakes, though largely brackish (used for fishing and irrigation of certain varieties of paddy and coconut).

Factors determining spatial distribution: 1. Rainfall – amount and distribution of rainfall (high in the north-east and west coast, low in Rajasthan). 2. Size of catchment area and river basin – the Ganga, Brahmaputra and Barak basins, though covering about one-third of the country’s area, have about 60% of total surface water resources. Rivers of the west coast (in Kerala) have plenty of water due to heavy rainfall; rivers like the Godavari, Krishna and Kaveri have most of their water used. 3. Topography – mountains, plains and plateaus affect runoff and storage. 4. Geology and soil – permeability affects groundwater recharge (alluvial plains have more groundwater; hard rocks of the Deccan have less). 5. Snow-fed vs rain-fed rivers – Himalayan rivers are perennial; peninsular rivers are seasonal.

India has 4% of the world’s water for 16% of its people; about 4,000 cubic km of precipitation yields 1,869 cubic km of surface and replenishable groundwater, of which about 1,122 cubic km is utilisable (690 cubic km surface, 432 cubic km groundwater). Distribution is uneven and depends on rainfall, size of catchments and river basins (the Ganga, Brahmaputra and Barak hold about 60% of surface water), topography, geology and whether rivers are snow-fed or rain-fed.

Question 3 (ii)

The depleting water resources may lead to social conflicts and disputes. Elaborate it with suitable examples?

Answer

With growing demand and decreasing availability, water has become a source of conflict at different levels:

1. Inter-state river water disputes

• Kaveri water dispute – between Karnataka and Tamil Nadu (also Kerala and Puducherry) over sharing Kaveri waters; protests and violence have occurred; resolved partly through the tribunal and Supreme Court (2018).
  • Krishna–Godavari dispute – between Maharashtra, Karnataka, Andhra Pradesh and Telangana.
  • Ravi–Beas and Sutlej–Yamuna Link canal dispute – between Punjab and Haryana (and Rajasthan).
  • Mahadayi/Mandovi dispute – Goa, Karnataka and Maharashtra.
  • Narmada – Gujarat, Madhya Pradesh, Maharashtra and Rajasthan.

2. International disputes – India–Pakistan (Indus Waters Treaty), India–Bangladesh (Ganga and Teesta waters), India–China (Brahmaputra).
3. Rural vs urban – cities draw water from rural areas, causing resentment among farmers (e.g. water supplied to Delhi, Chennai from distant sources).
4. Farmers vs industries – conflicts over water allocation to industries (e.g. protests against bottling plants like the Coca-Cola plant at Plachimada, Kerala, which depleted groundwater).
5. Within villages – disputes over wells, tanks and irrigation channels, often along caste lines; women spend hours fetching water.
6. Displacement by dams – Narmada Bachao Andolan, Tehri dam protests.

Way forward: efficient use, conservation, rainwater harvesting, equitable sharing, river basin planning and cooperation.

Depleting water leads to inter-state disputes (Kaveri between Karnataka and Tamil Nadu, Krishna–Godavari, the Sutlej–Yamuna Link between Punjab and Haryana, Mahadayi), international disputes (Indus, Teesta, Brahmaputra), rural–urban and farmer–industry conflicts (e.g. the Plachimada bottling plant protests), village-level disputes over wells, often along caste lines, and protests against displacement by dams — requiring conservation and equitable sharing.

Question 3 (iii)

What is watershed management? Do you think it can play an important role in sustainable development?

Answer

Watershed management basically refers to the efficient management and conservation of surface and groundwater resources. It involves the prevention of runoff and storage and recharge of groundwater through various methods like percolation tanks, recharge wells, check dams, contour bunding, gully plugging, etc. In the broad sense, watershed management includes the conservation, regeneration and judicious use of all resources — natural (land, water, plants and animals) and human — within a watershed. It aims at bringing about a balance between natural resources on the one hand and society on the other. Its success largely depends upon community participation.

Examples: - The central and state governments have initiated many watershed programmes, e.g. Haryali (a centrally sponsored project aimed at enabling rural people to conserve water for drinking, irrigation, fisheries and afforestation, executed by Gram Panchayats with people’s participation). - Neeru-Meeru (Water and You) programme in Andhra Pradesh. - Arvary Pani Sansad in Alwar, Rajasthan – people built water-harvesting structures like percolation tanks and dug-out ponds (johad) and check dams through people’s participation (Tarun Bharat Sangh, Rajendra Singh). - Ralegan Siddhi (Maharashtra, Anna Hazare) and Jhabua district (Madhya Pradesh). - Tamil Nadu made rainwater harvesting structures compulsory in all houses.

Role in sustainable development – yes: 1. Recharges groundwater and increases water availability for drinking and irrigation. 2. Controls soil erosion and land degradation; improves soil fertility. 3. Increases agricultural productivity and incomes, especially in dryland areas. 4. Regenerates vegetation and biodiversity; afforestation. 5. Reduces floods and droughts. 6. Community participation empowers people, reduces migration and poverty. 7. Ensures resources for future generations — the essence of sustainable development.

Watershed management is the efficient management and conservation of surface and groundwater — preventing runoff and recharging groundwater through percolation tanks, recharge wells and check dams — and broadly the conservation and judicious use of all natural and human resources in a watershed with community participation (e.g. Haryali, Neeru-Meeru, Arvary Pani Sansad in Alwar). Yes, it promotes sustainable development by recharging groundwater, checking soil erosion, raising farm productivity, regenerating vegetation, reducing floods and droughts, empowering communities and securing resources for future generations.

Topic checklist

• ☒ Water as a resource and its availability (Q 1 (i), 3 (i))
• ☒ Groundwater use and sectoral demand (Q 1 (ii), 1 (iii), 2 (ii), 2 (iii))
• ☒ Depletion, quality and conflicts (Q 2 (i), 2 (iv), 3 (ii))
• ☒ Watershed management (Q 3 (iii))

Total questions answered: 10 of 10