Geographical Perspective on Selected Issues and Problems

Why this chapter matters for UPSC: NCERT's last chapter takes four problems that sit where geography meets daily life: environmental pollution, urban waste, rural-urban migration and slums, and land degradation. Each is a recurring Mains theme: industrial pollution of rivers, the Namami Gange programme, solid waste, air pollution in megacities, the National Clean Air Programme, desertification, and the segregation of the poor in cities. In the 2026-27 NCERT reprint this is Chapter 9, "Geographical Perspective on Selected Issues and Problems", with the same text and an updated figure for the world's urban share. (Until October 2026 this site had no page for the chapter; it now has this one.)

Contemporary hook: The Central Pollution Control Board's latest assessment found 311 polluted stretches on 279 rivers (2022), the 46 worst of them with a biochemical oxygen demand above 30 mg per litre. Indian cities generated 1,85,195 tonnes of municipal solid waste a day in 2023-24, of which 62% was processed or treated. Census 2011 counted 6.55 crore people in slums. And ISRO's atlas puts 29.77% of India's land under degradation (2018-19). NCERT's four problems are measured, and none is solved.

🧠 First Principles — Read This First

Pollution is waste released faster than the environment can absorb it. NCERT defines environmental pollution as the result of "the release of substances and energy from waste products of human activities". Every medium has some self-purifying capacity: a river dilutes and decomposes what enters it, the air disperses smoke. Pollution begins when the concentration of waste exceeds that capacity, which is why NCERT's water section stresses that "the self-purifying capacity of water is unable to purify the water" once concentrations rise. The geography of pollution therefore follows the geography of people, industry and low flow: crowded river stretches below cities, industrial towns, and rivers in summer.

The other three problems are the same imbalance in different forms. Cities produce more waste than they collect and treat; migrants arrive faster than housing and services expand, so they settle in slums on "environmentally incompatible and degraded areas"; and land is used faster than its fertility recovers, so it degrades into wasteland. In each case NCERT's answer has two parts: treat the waste or damaged land as a resource (compost, energy, regenerated commons), and involve the community (the Daurala and Jhabua case studies). Read the chapter as one argument, not four.

PART 1 — Quick Reference

Types and Sources of Pollution (NCERT Table 12.1)

Pollution of the Ganga and the Yamuna (NCERT Table 12.2)

The Selected Issues in Numbers (latest)

PART 2 — Concepts & Narrative

Environmental Pollution

NCERT classifies pollution by the medium through which pollutants are transported and diffused: air, water, land and noise (Table 12.1).

Water Pollution

Indiscriminate use by a growing population and expanding industry has degraded water quality. Surface water from rivers, canals and lakes is never pure; it carries small quantities of suspended particles and organic and inorganic matter, and when their concentration rises the water becomes polluted and unfit for use. Natural sources (erosion, landslides, decay of plants and animals) add pollutants, but those from human activities are the real concern: industrial, agricultural and cultural, with industry the most significant contributor.

Industries produce waste water, poisonous gases, chemical residues, heavy metals, dust and smoke, and most industrial waste is disposed of in running water or lakes, so poisonous elements reach reservoirs and rivers and "destroy the bio-system of these waters". NCERT names the major water-polluting industries: leather, pulp and paper, textiles and chemicals. Agriculture adds inorganic fertilisers, pesticides and herbicides, washed into rivers, lakes and tanks or infiltrating to groundwater; fertilisers raise the nitrate content of surface water. Cultural activities, pilgrimage, religious fairs and tourism, also pollute. NCERT says almost all surface water sources in India are contaminated and unfit for human consumption.

Polluted water spreads water-borne diseases: diarrhoea, intestinal worms, hepatitis. NCERT cites the World Health Organization that about one-fourth of the communicable diseases in India are water-borne. Pollution of the Ganga, which flows through one of India's most populous regions, caused the greatest concern, and the National Mission for Clean Ganga and the Namami Gange Programme were launched to improve it.

Air Pollution

Air pollution is the addition of contaminants (dust, fumes, gas, fog, odour, smoke or vapour) to the air "in substantial proportion and duration that may be harmful to flora and fauna and to property". With rising use of fuels, emissions of toxic gases have increased. Combustion of fossil fuels, mining and industries are the main sources, releasing oxides of sulphur and nitrogen, hydrocarbons, carbon dioxide, carbon monoxide, lead and asbestos. Air pollution causes diseases of the respiratory, nervous and circulatory systems. Urban smog, a smoky fog over cities, is harmful to health, and air pollution can cause acid rain: NCERT notes that rainwater analysis in urban areas shows the pH of the first rain after summer is always lower than that of later rains.

Noise Pollution

Noise pollution is noise from different sources at levels that are "unbearable and uncomfortable" to people, a serious concern only in recent years because of technological change. Its main sources are factories, mechanised construction and demolition, automobiles and aircraft, with periodic noise from sirens and loudspeakers at festivals and community events. Steady noise is measured in decibels (dB). The biggest nuisance is traffic noise, whose intensity depends on the type of aircraft, vehicle or train and the condition of the road and vehicle; at sea, noise is confined to harbours during loading and unloading. Noise is location-specific and declines with distance from its source, but it is hazardous in many metropolitan and big cities.

Urban Waste Disposal

Urban areas are marked by overcrowding, congestion, inadequate facilities and poor sanitation, and solid waste has become significant because of the huge growth in its quantity. Solid waste is a variety of old and used articles: stained small pieces of metal, broken glass, plastic containers, polythene bags, ash, floppies and CDs, also called refuse, garbage and rubbish. It comes from two sources: households and industrial or commercial establishments. Household waste is dumped on public land or at private contractors' sites; industrial waste is collected and disposed of through municipal facilities at low-lying public grounds (landfills). Ash and debris from industry, thermal power stations and construction or demolition pose serious problems.

Solid waste harms health through obnoxious smells and by harbouring flies and rodents, carriers of typhoid, diphtheria, diarrhoea, malaria and cholera; carelessly handled, it is spread by wind and rain. Industrial waste dumped in rivers pollutes them, and untreated sewage and city industry cause serious health problems downstream. NCERT's figures: in metropolitan cities such as Mumbai, Kolkata, Chennai and Bengaluru about 90% of solid waste is collected and disposed of, but in most other cities and towns 30 to 50% is left uncollected, accumulating on streets, open spaces and wastelands. Its remedy: treat wastes as a resource for energy and compost, since untreated waste ferments slowly and releases toxic biogas, including methane.

The latest CPCB report on the Solid Waste Management Rules (2023-24) shows the national picture: 1,85,195 tonnes a day generated, 1,79,479 collected (about 97%), 1,13,935 processed or treated (62%), 32,531 sent to sanitary landfills (17%), and 38,729 tonnes a day (21%) neither treated nor landfilled. Those 2016 rules have been superseded by the Solid Waste Management Rules, 2026, notified on 27 January 2026 and in force from 1 April 2026, which require waste to be separated into four streams at source.

Rural-Urban Migration

Population flows from villages to towns because of the demand for labour in cities, few job opportunities in villages and the unbalanced pattern of development between the two. Because small and medium cities offer few opportunities, the poor often bypass them and go straight to the mega cities. NCERT's box adds the world picture: urban population grows by natural increase, net in-migration and the reclassification of rural places as urban; and in India, it says, after 1961 about 60% of urban growth came from natural increase and about 29% from rural-urban migration. Its 2026-27 text gives the world's urban share as 55%, rising to 68% by 2050; the UN's World Urbanization Prospects 2025 now puts it at 57.8% in 2025 and 67.3% by 2050.

Problems of Slums

Urban and rural settlements differ in function and have become separate cultural, social, political, economic and technological worlds. India is predominantly rural (about 69% of the population in 2011), and its villages, which Mahatma Gandhi considered ideal republics, are still mostly poor and engaged in primary activities, often forming the hinterland of a city. But Indian cities are not homogeneous: they are more internally differentiated than any other area. At the top are farm houses and high-income localities with wide roads, street lights, water and sanitation, lawns, parks, playgrounds and security; at the other extreme are slums, jhuggi-jhopri clusters and shanty colonies, inhabited by people "forced to migrate" from villages who could not afford proper housing because of high rents and land prices, occupying "environmentally incompatible and degraded areas".

NCERT defines slums as "residential areas of the least choice": dilapidated houses, poor hygiene and ventilation, no drinking water, light or toilets, open defecation, unregulated drainage and overcrowded narrow streets, all serious health and socio-environmental hazards. Most slum dwellers work in low-paid, high-risk, unorganised urban jobs; they are undernourished, prone to disease and unable to educate their children, and poverty makes them vulnerable to drug abuse, alcoholism, crime, vandalism, escapism, apathy and ultimately social exclusion. NCERT mentions the Swachh Bharat Mission here as a mission "to improve the quality of life in urban slums"; it is in fact a sanitation mission, launched on 2 October 2014, whose urban second phase (SBM-U 2.0) began on 1 October 2021.

Census 2011 is the reference for the scale: its Primary Census Abstract for slums counts 6,54,94,604 people in slums, in about 1.39 crore households, the largest number in Maharashtra (1.18 crore).

Land Degradation

Pressure on farmland rises not only because land is limited but because its quality deteriorates. Soil erosion, waterlogging, salinisation and alkalinisation lead to land degradation, "a temporary or a permanent decline in productive capacity of the land". Not all degraded land is wasteland, but unchecked degradation may turn it into wasteland. The National Remote Sensing Centre (NRSC) has classified wastelands from satellite data by the processes that created them:

• Mainly natural: gullied or ravinous land, desertic or coastal sands, barren rocky areas, steep sloping land and glacial areas.
• Natural and human: waterlogged and marshy areas, land affected by salinity and alkalinity, and land with or without scrub.
• Mainly human: degraded shifting cultivation areas, degraded land under plantation crops, degraded forests, degraded pastures, and mining and industrial wastelands.

NCERT concludes that wastelands made by human processes "are more important than natural processes" (it refers to a "Table 12.3" that the printed chapter does not contain).

Jhabua: Reversing Degradation (NCERT case study)

Jhabua district lies in the westernmost agro-climatic zone of Madhya Pradesh and is, NCERT says, one of the five most backward districts in the country, with a high concentration of tribal people (mostly Bhils), whose poverty has been deepened by the degradation of forest and land. Watershed management programmes funded by the Ministries of Rural Development and Agriculture have been implemented successfully there; those funded by Rural Development and run by the Rajiv Gandhi Mission for Watershed Management treated 20% of the district's area in five years. Watershed management, NCERT explains, recognises the link between land, water and vegetation and improves livelihoods through natural resource management and community participation.

In the Petlawad block, the Bhils of Sat Rundi hamlet of Karravat village revitalised large parts of their common property resources: each household planted and maintained one tree on the common land, fodder grass was planted on the pasture, and the land was protected by social fencing for at least two years, with stall-feeding instead of open grazing afterwards. When a villager from a neighbouring village encroached on the commons, the community resolved it by making him a member of the user group and sharing the benefits. The case ties this chapter to the CPRs of the land-resources chapter: degradation is reversed by rules the community makes and keeps.

PART 3 — UPSC Integration

Frames that score. For river pollution, use NCERT's three sources (industrial, agricultural, cultural; industry the largest) and Table 12.2, then the CPCB's 2022 count and the Namami Gange status with its date. For solid waste, set NCERT's 90% (metros) and 30-50% uncollected (other towns) against the CPCB's 2023-24 national figures and the 2026 Rules. For land degradation, use the NRSC process classes and the two atlases, then the Jhabua case for the solution.

Exam Strategy

For Prelims: the four pollution types and their pollutants; the Yamuna stretches (Delhi to the Chambal; Mathura and Agra); WHO's one-fourth of communicable diseases being water-borne (NCERT); the first rain's lower pH; decibels; Daurala (near Meerut) and Jhabua (Madhya Pradesh, Petlawad block, Bhils) as case studies; the NRSC wasteland classes; noise limits (residential 55/45 dB(A)); PM10 and PM2.5 standards.

For Mains: take one problem, describe its geography with NCERT's examples, quantify it from the latest official report, and close with a community-based solution from NCERT's case studies.

Avoid: mixing the wasteland figure (16.96% of area) with the land-degradation figure (29.77%); quoting NCERT's 55% world urban share as current; and describing the Swachh Bharat Mission as an urban renewal mission.

Practice Questions

Practice (UPSC-pattern, not past papers). Questions 1 to 4 are NCERT's own exercise MCQs.

Prelims:

1. Which one of the following rivers is highly polluted?
   (a) Brahmaputra
   (b) Satluj
   (c) Yamuna
   (d) Godavari

2. Which one of the following diseases is caused by water pollution?
   (a) Conjunctivitis
   (b) Diarrhoea
   (c) Respiratory infections
   (d) Bronchitis

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

4. Push and pull factors are responsible for:
   (a) Migration
   (b) Land degradation
   (c) Slums
   (d) Air pollution

5. Consider the following types of wasteland in NRSC's classification:
   

   1. Gullied or ravinous land
      
   2. Degraded shifting cultivation area
      
   3. Land affected by salinity and alkalinity
      Which of the above does NCERT list as caused mainly by human action?
      (a) 1 only
      (b) 2 only
      (c) 2 and 3 only
      (d) 1, 2 and 3

6. Under the Noise Pollution (Regulation and Control) Rules, 2000, the permitted night-time ambient noise level in a residential area is:
   (a) 40 dB(A)
   (b) 45 dB(A)
   (c) 55 dB(A)
   (d) 70 dB(A)

Answer notes: Q5, gullies are mainly natural, salinity and alkalinity natural and human; Q6, 55 by day and 45 at night.

Mains:

1. Describe the nature of water pollution in India. What has the Namami Gange programme achieved? (250 words)
2. Describe the problem of slums in India. Why do the urban poor settle on degraded land? (150 words)
3. Suggest measures for the reduction of land degradation, with an example of community action. (150 words)

📦 Revision Capsule

Sources

• NCERT, India: People and Economy (Class XII), ch. 12 "Geographical Perspective on Selected Issues and Problems", Tables 12.1-12.2 (2021-22 print) and ch. 9 (Reprint 2026-27): 2021 book archive, Wayback copy; 2026-27 book archive.
• Central Pollution Control Board, Polluted River Stretches for Restoration of Water Quality - 2022: cpcb.nic.in PDF; Annual Report on Solid Waste Management 2023-24; Noise Pollution (Regulation and Control) Rules, 2000, as amended: cpcb.nic.in PDF.
• PIB (Ministry of Jal Shakti), Namami Gange Mission-II, 13 February 2023: pib.gov.in; status of the programme, 23 March 2026: pib.gov.in; progress, 2 April 2026: pib.gov.in.
• Census of India 2011, Primary Census Abstract for Slum: censusindia.gov.in catalogue.
• PIB (Ministry of Rural Development), Wastelands Atlas of India 2019, 5 November 2019: pib.gov.in; ISRO Space Applications Centre, Desertification and Land Degradation Atlas of India (2021): vedas.sac.gov.in PDF; PIB, land degradation and the 26 Mha target, 7 August 2023: pib.gov.in.
• Indian Council for Enviro-Legal Action v. Union of India, Supreme Court, 13 February 1996: indiankanoon.org.
• UN DESA, World Urbanization Prospects 2025: Summary of Results: desapublications.un.org.