NCERT Solutions for Class 12 Geography Chapter 9: Geographical Perspective on Selected Issues and Problems (NCERT 2026–27)

These Class 12 Geography Chapter 9 solutions cover Geographical Perspective on Selected Issues and Problems, the concluding chapter (Unit V: Environmental Pollution) of the NCERT textbook India: People and Economy, updated for the 2026–27 session. The chapter studies environmental pollution (air, water, land and noise), the special concern of river pollution and the Namami Gange Programme, urban waste disposal, rural–urban migration, the problems of slums and land degradation. Below you get step-by-step answers to every NCERT exercise question reproduced verbatim, plus key terms, extra practice, MCQs, Assertion–Reason questions and FAQs.

Class: 12 Subject: Geography Book: India: People and Economy Chapter: 9 (Unit V) Topic: Environmental Pollution & Selected Issues Session: 2026–27
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Class 12 Geography Chapter 9 – Overview

Chapter 9, Geographical Perspective on Selected Issues and Problems, examines the environmental and social problems that have arisen from rapid population growth, industrialisation and urbanisation in India. Environmental pollution results from the release of substances and energy from the waste products of human activities; it is classified as air, water, land and noise pollution on the basis of the medium through which pollutants travel. The chapter highlights that industry is the most significant contributor to water pollution, that rivers like the Ganga and Yamuna are critically polluted, and discusses the Namami Gange Programme launched to clean the Ganga. It then turns to urban waste disposal, rural–urban migration (caused by push and pull factors), the problems of slums (illustrated by Dharavi) and land degradation caused by both natural and human processes, along with watershed management as a corrective measure.

Key Concepts & Terms

Pollution vs pollutant: a pollutant is the substance or energy (e.g. smoke, sewage, noise) that contaminates the environment, whereas pollution is the resulting state of contamination — the actual degradation of air, water, land or the acoustic environment caused by those pollutants.

Air pollution: the addition of contaminants such as dust, fumes, gas, fog, odour, smoke or vapour to the air in harmful proportion and duration. Main sources are combustion of fossil fuels, mining and industries, which release oxides of sulphur and nitrogen, hydrocarbons, carbon dioxide, carbon monoxide, lead and asbestos.

Water pollution: contamination of surface and ground water by sewage, urban run-off, industrial effluents, agricultural run-off (fertilisers, pesticides) and cultural activities. Industry is the most significant contributor; major polluting industries are leather, pulp and paper, textiles and chemicals.

Land (soil) pollution: degradation of land by human and animal excreta, garbage, pesticide and fertiliser residue, alkalinity, fluorides and radioactive substances arising from improper human activities and untreated waste.

Noise pollution: an unbearable and uncomfortable state caused by noise, measured in decibels (dB); the biggest source is traffic, followed by factories, construction, aircraft and loudspeakers. It is location-specific and declines with distance.

Namami Gange Programme: a Union-Government mission for cleaning the Ganga through sewerage treatment, monitoring industrial effluents, river-front development, afforestation, surface cleaning, ‘Ganga Grams’ and public awareness.

Urban waste / solid waste: old and used refuse, garbage and rubbish from household and industrial sources; in metros about 90% is collected, but in many other cities 30–50% is left uncollected, causing health hazards.

Push and pull factors: push factors (rural poverty, low job opportunities, indebtedness) drive people out of villages, while pull factors (perceived jobs, higher wages, better facilities) attract them to cities — together they cause rural–urban migration.

Slums: residential areas of the least choice with dilapidated houses, poor hygiene and ventilation, and a lack of basic amenities; Dharavi in Mumbai is Asia’s largest slum.

Land degradation: a temporary or permanent decline in the productive capacity of land caused by soil erosion, waterlogging, salinisation and alkalinisation, due to natural and human processes; watershed management programmes help reverse it.

NCERT Exercise – Full Solutions

All questions below are reproduced verbatim from the NCERT textbook’s end-of-chapter Exercises. Answers are original, written in exam-ready style.

1. Choose the right answers of the following from the given options.

(i) Which one of the following river is highly polluted? (a) Brahmaputra    (b) Satluj    (c) Yamuna    (d) Godavari

ANSWER (c) Yamuna. The stretch of the Yamuna from Delhi to its confluence with the Chambal is one of the most heavily polluted river stretches in India, owing to extraction of water for irrigation, agricultural run-off and the domestic and industrial waste of Delhi flowing into it.

(ii) Which one of the following deseases is caused by water pollution? (a) Conjunctivitis    (b) Diarrhorea    (c) Respiratory infections    (d) Bronchitis

ANSWER (b) Diarrhoea. Diarrhoea is a water-borne disease spread through contaminated water. The WHO notes that about one-fourth of communicable diseases in India are water-borne. Respiratory infections and bronchitis are caused by air pollution.

(iii) Which one of the following is the cause of acid rain? (a) Water pollution    (b) Land pollution    (c) Noise pollution    (d) Air pollution

ANSWER (d) Air pollution. Acid rain is caused by air pollution: oxides of sulphur and nitrogen released by burning fossil fuels dissolve in rainwater to form acids, lowering its pH.

(iv) Push and pull factors are responsible for– (a) Migration    (b) Land degradation    (c) Slums    (d) Air pollution

ANSWER (a) Migration. Push factors (rural poverty, low job opportunities, indebtedness) and pull factors (perceived jobs and better facilities in cities) together cause rural–urban migration.

2. Answer the following questions in about 30 words.

(i) What is the difference between pollution and pollutants?

ANSWER A pollutant is the substance or energy — such as smoke, sewage or noise — that contaminates the environment. Pollution is the resulting state of contamination, the degradation of air, water or land caused by those pollutants.

(ii) Describe the major source of air pollution.

ANSWER The major sources of air pollution are combustion of fossil fuels, mining and industries. These release toxic gases such as oxides of sulphur and nitrogen, hydrocarbons, carbon dioxide, carbon monoxide, lead and asbestos into the atmosphere.

(iii) Mention major problems associated with urban waste disposal in India.

ANSWER Solid wastes create obnoxious smells and harbour flies and rodents that carry diseases like typhoid and cholera. In many cities 30–50% of waste is left uncollected, accumulating on streets and wastelands, while dumping of industrial waste into rivers pollutes water.

(iv) What are the effects of air pollution on human health.

ANSWER Air pollution causes diseases of the respiratory, nervous and circulatory systems. Urban smog harms human health, while acid rain damages property and crops; long exposure leads to lung and breathing disorders.

3. Answer the following questions in about 150 words.

(i) Describe the nature of water pollution in India.

ANSWER Water pollution in India occurs when the concentration of suspended particles and organic and inorganic substances in water rises so high that water becomes unfit for use and its self-purifying capacity fails. Although natural sources such as erosion and decomposition contribute, human activities are the real causes of concern. Industry is the most significant contributor: leather, pulp and paper, textile and chemical industries discharge poisonous gases, chemical residuals and heavy metals, mostly into running water and lakes, destroying their bio-systems. Agriculture adds inorganic fertilisers, pesticides and herbicides that wash into rivers and infiltrate groundwater, raising nitrate levels. Cultural activities such as pilgrimage, religious fairs and tourism also pollute rivers. As a result, almost all surface water sources are contaminated and unfit for consumption, causing water-borne diseases such as diarrhoea, intestinal worms and hepatitis. The Ganga and the Yamuna, flowing through densely populated regions, are among the worst affected, prompting the launch of the Namami Gange Programme.

(ii) Describe the problem of slums in India.

ANSWER Slums are the residential areas of the least choice in cities, inhabited mainly by people who migrated from rural areas in search of livelihood but could not afford proper housing because of high rents and land costs, so they occupy environmentally degraded and incompatible areas. They are marked by dilapidated houses, poor hygienic conditions, poor ventilation and a lack of basic amenities like drinking water, light and toilets. Open defecation, unregulated drainage and overcrowded, narrow streets create serious health and socio-environmental hazards. Dharavi in Mumbai — Asia’s largest slum — illustrates these conditions, with temporary structures, uncollected garbage and stagnant foul water. Most slum dwellers work in low-paid, high-risk, unorganised sectors. Consequently they are undernourished, prone to disease, and unable to give their children proper education. Poverty makes them vulnerable to drug abuse, crime and ultimately social exclusion. Missions like the Swachh Bharat Mission aim to improve their quality of life.

(iii) Suggest measures for reduction of land degradation.

ANSWER Land degradation is the temporary or permanent decline in the productive capacity of land, caused by soil erosion, waterlogging, salinisation and alkalinisation arising from natural and human processes. The following measures can reduce it: 1. Afforestation and tree planting on degraded common lands to bind the soil, as the Bhils of Petlawad block (Jhabua) did by planting and maintaining trees and fodder grass. 2. Watershed management programmes that recognise the linkage between land, water and vegetation and improve livelihoods through natural-resource management and community participation, as successfully done in Jhabua district. 3. Social fencing of pastures and stall feeding of cattle instead of open grazing to allow vegetation to recover. 4. Controlling overgrazing, checking gully erosion, preventing waterlogging through proper drainage, and reclaiming saline and alkaline lands. 5. Treating degraded land as a resource, managing soil fertility, rainwater harvesting and recharging aquifers to dilute contaminants, with active Government–NGO–community partnership.

Extra Practice Questions

Short Answer Type Questions

Q1. On what basis is pollution classified into four types?

ANSWERPollution is classified on the basis of the medium through which pollutants are transported and diffused. On this basis it is divided into (i) air pollution, (ii) water pollution, (iii) land pollution and (iv) noise pollution.

Q2. Why is industry considered the most significant contributor to water pollution?

ANSWERIndustries produce industrial wastes, polluted waste water, poisonous gases, chemical residuals and heavy metals, most of which are disposed of in running water or lakes. Leather, pulp and paper, textile and chemical industries pour poisonous elements into rivers, destroying their bio-systems.

Q3. What is noise pollution and in what unit is noise measured?

ANSWERNoise pollution is an unbearable and uncomfortable state caused by noise from sources such as factories, construction, automobiles and aircraft. The level of steady noise is measured by sound level expressed in decibels (dB); it is location-specific and declines with distance.

Q4. List any four objectives of the Namami Gange Programme.

ANSWERFour objectives are: developing sewerage treatment systems in towns; monitoring of industrial effluents; afforestation along the bank to increase biodiversity; and creating public awareness to avoid adding pollutants to the river, even in the form of rituals.

Q5. What are push and pull factors in rural–urban migration?

ANSWERPush factors are conditions that drive people out of villages — poverty, indebtedness, low job opportunities and unbalanced development. Pull factors are attractions of cities — perceived job promises, higher wages and better facilities — that draw migrants towards mega cities.

Long Answer Type Questions

Q1. Discuss the causes and consequences of rural–urban migration in India with reference to the case of Ramesh.

ANSWERRural–urban migration is the flow of population from villages to cities caused by push factors (rural poverty, indebtedness, low job opportunities and unbalanced development between urban and rural areas) and pull factors (perceived jobs and better living in cities). Ramesh’s case illustrates this: caught in poverty and family debt, he discontinued studies after the ninth standard and, impressed by successful out-migrants, moved to Ludhiana, then Surat, learning welding and moving across cities with a contractor. He now remits about Rs. 20,000 a year, improving his family’s standard of living, schooling of children and even purchase of land. The consequences are mixed: migration raises rural incomes through remittances, but in developing countries the poor and unskilled often end up in menial, low-wage informal jobs. Because wages are too low to bring families along, spouses are left behind to look after children and the elderly, so the migration stream is dominated by males, causing the pain of family separation. In cities, such migration swells slums and strains infrastructure.

Q2. Explain the four types of pollution along with their pollutants and sources.

ANSWERPollution is classified by the medium of transport into four types. The pollutants and sources are summarised below (based on the textbook’s Table 9.1):
Pollution typePollutants involvedSources of pollution
Air pollutionOxides of sulphur (SO2, SO3) and nitrogen, carbon monoxide, hydro-carbons, ammonia, lead, aldehydes, asbestos and berylliumCombustion of coal, petrol and diesel; industrial processes; solid waste disposal; sewage disposal
Water pollutionOdour, dissolved and suspended solids, ammonia and urea, nitrate and nitrites, chloride, fluoride, oil and grease, pesticide residue, coliform bacteria, sulphates, heavy metals (lead, arsenic, mercury) and radioactive substancesSewage disposal, urban run-off, toxic effluents from industries, run-off over cultivated land and nuclear power plants
Land pollutionHuman and animal excreta, viruses and bacteria, garbage, pesticide and fertiliser residue, alkalinity, fluorides and radioactive substancesImproper human activities, disposal of untreated industrial waste, use of pesticides and fertilisers
Noise pollutionHigh level of noise above the tolerance levelAircraft, automobiles, trains, industrial processing and advertising media
Each type damages flora, fauna, property and human health, making pollution control essential for sustainable development.

Q3. Examine the problem of urban waste disposal in India and suggest sustainable solutions.

ANSWERUrban areas in India suffer from overcrowding, congestion and inadequate facilities, producing enormous quantities of solid waste — metals, glassware, plastic, polythene, ash and other refuse from household and industrial sources. In metros like Mumbai, Kolkata, Chennai and Bengaluru about 90% of solid waste is collected and disposed of, but in most other cities 30–50% is left uncollected, accumulating on streets, open spaces and wastelands. This causes serious health hazards: solid waste creates obnoxious smells and harbours flies and rodents that carry typhoid, diphtheria, diarrhoea, malaria and cholera. Ashes and debris from industries and thermal power houses, and the dumping of industrial waste into rivers, worsen water pollution and downstream health problems. Untreated waste also ferments and releases toxic biogas, including methane. Sustainable solutions include treating waste as a resource and using it to generate energy and compost, segregating and recycling materials (as ragpickers already do informally), strengthening municipal collection in smaller towns, treating industrial effluents before disposal, and following the “polluter pays” principle, as demonstrated in the Daurala model of ecological restoration near Meerut.

MCQs & Assertion–Reason

1. Pollution is classified into four types on the basis of:

(a) the cost of cleaning    (b) the medium through which pollutants are transported    (c) the region affected    (d) the season

2. The most significant contributor to water pollution is:

(a) agriculture    (b) cultural activities    (c) industry    (d) natural erosion

3. The level of steady noise is measured in:

(a) hertz    (b) decibels    (c) lumens    (d) pascals

4. Asia’s largest slum, mentioned in the chapter, is:

(a) Dharavi    (b) Kibera    (c) Orangi    (d) Bhalswa

5. The Namami Gange Programme is also referred to as the National Mission for:

(a) Clean Air    (b) Clean Ganga    (c) Clean Yamuna    (d) Clean Coast

6. According to the WHO, about what fraction of communicable diseases in India are water-borne?

(a) one-half    (b) one-third    (c) one-fourth    (d) one-tenth

7. Acid rain is mainly caused by:

(a) water pollution    (b) land pollution    (c) noise pollution    (d) air pollution

8. In metropolitan cities such as Mumbai and Kolkata, the share of solid waste collected and disposed of is about:

(a) 30%    (b) 50%    (c) 70%    (d) 90%

9. The successful case of watershed management discussed in the chapter is from:

(a) Jhabua, Madhya Pradesh    (b) Daurala, Uttar Pradesh    (c) Talcher, Odisha    (d) Ludhiana, Punjab

10. Which of the following is NOT a process that leads to land degradation?

(a) soil erosion    (b) waterlogging    (c) salinisation    (d) afforestation

Answer key: 1-(b), 2-(c), 3-(b), 4-(a), 5-(b), 6-(c), 7-(d), 8-(d), 9-(a), 10-(d).

For each Assertion–Reason question, choose: (A) Both true and the Reason correctly explains the Assertion; (B) Both true but the Reason is not the correct explanation; (C) Assertion true, Reason false; (D) Assertion false, Reason true.

A-R 1. Assertion: Surface water from rivers and lakes is never completely pure.

Reason: It always contains small quantities of suspended particles and organic and inorganic substances.

A-R 2. Assertion: The Yamuna is one of the most heavily polluted rivers in India.

Reason: Domestic and industrial waste of Delhi flows into it along with agricultural run-off.

A-R 3. Assertion: Noise pollution affects all areas equally regardless of distance.

Reason: Noise pollution is location-specific and its intensity declines with increase in distance from the source.

A-R 4. Assertion: Rural–urban migration in India is dominated by males.

Reason: Low urban wages force migrants to leave their spouses behind in villages to look after children and the elderly.

A-R 5. Assertion: All degraded land is wasteland.

Reason: An unchecked process of degradation may convert degraded land into wasteland.

Answer key: 1-(A), 2-(A), 3-(D), 4-(A), 5-(D).

Exam Tips & Common Mistakes

How to score full marks in this chapter

Memorise the four types of pollution with their pollutants and sources (Table 9.1) — it is examiner-friendly material for short answers. Keep the pollution vs pollutant distinction crisp. For the Ganga/Yamuna, link river pollution to the Namami Gange Programme and list its objectives. For 150-word answers on slums, water pollution and land degradation, write in clear points with a definition, causes/nature, and a measure or example (Dharavi, Daurala, Jhabua, Swachh Bharat Mission). Always anchor migration answers in the push–pull framework and Ramesh’s case study.

Common mistakes to avoid

  • Confusing pollution (the state of contamination) with pollutant (the contaminating substance).
  • Attributing acid rain or respiratory diseases to water pollution — they are caused by air pollution.
  • Forgetting that industry, not agriculture, is the most significant contributor to water pollution.
  • Measuring noise in hertz — steady noise level is measured in decibels (dB).
  • Assuming all degraded land is wasteland — it becomes wasteland only if degradation is unchecked.
  • Writing migration answers without mentioning push and pull factors or the male-dominated, remittance-based pattern.

Frequently Asked Questions

What is Chapter 9 of Class 12 Geography (India: People and Economy) about?

Chapter 9, Geographical Perspective on Selected Issues and Problems, studies environmental pollution (air, water, land and noise), river pollution and the Namami Gange Programme, urban waste disposal, rural–urban migration, the problems of slums and land degradation, with case studies and corrective measures like watershed management.

What is the difference between pollution and pollutants?

A pollutant is the substance or energy — such as smoke, sewage or noise — that contaminates the environment, while pollution is the resulting state of contamination, i.e. the degradation of air, water or land caused by those pollutants.

How many questions are in the NCERT exercise of Chapter 9 and are all solved here?

The NCERT exercise has three main parts: 4 multiple-choice questions, 4 short questions (about 30 words) and 3 long questions (about 150 words). All of them are reproduced verbatim and answered step by step on this page, updated for the 2026–27 session.

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