Geographical Perspective on Selected Issues and Problems

• Builds on Fundamentals of Human Geography Chapter 2 (World Population — migration and push–pull factors) and Chapter 3 (Human Development).
• Builds on this book's Chapter 2 (Human Settlements: urbanisation, cities), Chapter 3 (Land Resources: wastelands, common property resources), Chapter 4 (Water Resources: water quality, watershed management) and Chapter 6 (Planning and Sustainable Development). Here they come together as problems.
• Last chapter of the book — there is no next chapter; it closes the book on the question of sustainable development.
• UPSC: GS1 (urbanisation, migration, slums), GS3 (environment, pollution, waste management, conservation). Prelims asks acid rain gases, smog, noise levels, water-borne diseases, waste rules; Mains asks Delhi's air, solid waste, desertification and migration trends.

• Pollution is classified by medium: air, water, land, noise (Table 9.1).
• Industry is the biggest water polluter; ≈ one-fourth of communicable diseases are water-borne (WHO).
• Fuel burning → smog and acid rain; traffic is the worst noise source; noise measured in dB.
• Metros collect ≈ 90% of solid waste; other towns leave 30–50% uncollected.
• Poor migrants bypass small towns for mega cities; the stream is male-dominated; slums like Dharavi result.
• Wastelands: natural, mixed and human-made (the most important); Jhabua and Daurala show recovery.

Environmental pollution results from the release of substances and energy from waste products of human activities. It is classified by the medium through which pollutants are carried and spread: air, water, land and noise pollution.

Growing population and industry have degraded water quality. Surface water is never pure; when suspended and dissolved substances become too concentrated, water becomes unfit for use and its self-purifying capacity fails. Natural sources (erosion, landslides, decay of plants and animals) exist, but human sources — industrial, agricultural and cultural — are the real concern, and industry is the most significant. Industries release waste water, poisonous gases, chemical residues, heavy metals, dust and smoke, mostly into rivers and lakes; the major water-polluting industries are leather, pulp and paper, textiles and chemicals. Farm chemicals (fertilisers, pesticides, herbicides) wash into water bodies and seep to groundwater; fertilisers raise nitrate in surface water. Pilgrimages, fairs and tourism add more. Almost all surface water in India is contaminated and unfit to drink.

Polluted water causes diarrhoea, intestinal worms, hepatitis and more; the WHO says about one-fourth of India's communicable diseases are water-borne. The Ganga, flowing through one of the most populous regions, causes most concern: the National Mission for Clean Ganga was started and the Namami Gange Programme launched.

Air pollution is the addition of contaminants — dust, fumes, gas, fog, odour, smoke or vapour — in such amount and duration that they harm plants, animals and property. Growing fuel use has raised toxic emissions. The main sources are combustion of fossil fuels, mining and industry, releasing oxides of sulphur and nitrogen, hydrocarbons, CO₂, CO, lead and asbestos. Air pollution causes diseases of the respiratory, nervous and circulatory systems. Smoky fog over cities is urban smog, very harmful to health. Air pollution also causes acid rain: rainwater studies show the first rain after summer has a lower pH than later rains — it washes out the pollutants that accumulated in the dry months.

Noise pollution is the state of unbearable, uncomfortable sound, a serious concern only recently because of new technology. Sources: factories, mechanised construction and demolition, vehicles and aircraft, plus periodic noise from sirens and loudspeakers at festivals and community events. Steady noise is measured in decibels (dB). The biggest nuisance is traffic, whose intensity depends on the type of aircraft, vehicle or train and on the condition of roads and vehicles. At sea, noise is confined to harbours (loading and unloading); industrial noise varies with the industry. Noise is location-specific and its intensity falls with distance from the source — industrial areas, highways, airports. It is hazardous in many big cities.

The table gives the ambient noise standards of the Noise Pollution (Regulation and Control) Rules, 2000 — Beyond NCERT.

Cities face overcrowding, congestion, weak facilities, poor sanitation and foul air. Solid waste — scrap metal, broken glass, plastic containers, polythene bags, ash, discs — comes from households and from industry and commerce. Household waste goes to public land or private contractors' sites; industrial waste is collected and dumped by municipalities on low-lying land (landfills). Ash and debris from industries, thermal power houses and construction are a growing problem. Solid waste causes smell and breeds flies and rodents that carry typhoid, diphtheria, diarrhoea, malaria and cholera; it is spread by wind and rain. In Mumbai, Kolkata, Chennai and Bengaluru about 90 per cent is collected; elsewhere 30–50 per cent lies uncollected on streets and open spaces. Waste should be treated as a resource for energy and compost; untreated waste ferments slowly and releases toxic biogas including methane. Industries in and around cities dump waste into rivers, and city sewage harms people downstream.

People move from villages to cities because of high demand for labour in cities, few jobs in villages, and unbalanced development between the two. Since small and medium towns offer little, poor migrants often bypass them and go straight to mega cities. Poor, semi-literate and unskilled migrants usually end up in low-paid, informal jobs; since wages cannot support a family in the city, wives stay behind with children and elders — so the rural–urban stream is dominated by men.

Urban and rural areas differ in function, sometimes complementing each other, and have become separate cultural, social, political, economic and technological worlds. India is mostly rural (about 69 per cent in 2011) and Gandhi saw villages as ideal republics, yet many villages are poor, depend on primary activities and serve as the hinterland of a city. Cities are themselves highly differentiated: at the top, farmhouses and high-income localities with wide roads, streetlights, water, sanitation, parks and security; at the bottom, slums, jhuggi-jhopri clusters and shanty colonies of rural migrants who cannot afford rent or land and occupy environmentally unsuitable, degraded land. Slums have dilapidated houses, poor hygiene and ventilation, and no drinking water, light or toilets; open defecation, unregulated drainage and narrow crowded lanes are health hazards. Slum dwellers work in low-paid, high-risk, unorganised jobs, are undernourished and sick, cannot educate their children, and poverty pushes some toward drugs, alcoholism, crime and social exclusion.

Pressure on farmland grows both from its limited area and from falling quality. Soil erosion, waterlogging, salinisation and alkalinisation degrade land. Land degradation is a temporary or permanent decline in productive capacity; not all degraded land is wasteland, but unchecked degradation leads there. Degradation has natural and human causes. The National Remote Sensing Centre (NRSC) classified wastelands using remote sensing, by the process that created them; NCERT concludes that human-made wastelands matter more than natural ones.

Try each question yourself first, then open the outline to compare. The four multiple-choice questions are in the self-check below.

Numbers

One-liners

• Pollution types are named by medium: air, water, land, noise.
• Industry is the biggest single source of water pollution.
• Yamuna's problem is both waste added and water withdrawn.
• SO₂ and NOx cause acid rain; the first rain after summer is the most acidic.
• Traffic is the worst noise; noise falls with distance from the source.
• Waste is a resource: compost and energy.
• Rural–urban migration is male-dominated and bypasses small towns.
• Slums sit on degraded land, yet power the urban economy.
• Human-made wastelands outweigh natural ones.

Traps to avoid

• Water pollution disease (NCERT MCQ) = diarrhoea, not conjunctivitis or bronchitis.
• Acid rain = air pollution (SO₂, NOx), not water or land pollution.
• Shallow hand-pump water does not cause fluorosis.
• Pollution ≠ pollutant: process vs agent.
• NCERT's ‘Table 12.3’ does not exist in this edition.
• ‘Coliform MPM’ should be MPN (most probable number).
• SBM covers rural and urban sanitation, not only urban slums.
• Most polluted river in the exercise: Yamuna.

Prelims — what UPSC asks

• Air and acid rain: most common pollutant (1979), Taj Mahal (1984, 1994), acid-rain gases (1988, 2010, 2013, 2022), photochemical smog (2003, 2013), steel-plant pollutants (2014), AQI gases (2016), coal ash and power plants (2020).
• Water and land: major killers in developing countries (1993), effluents (1996), hand-pump diseases (1996), nitrogenous fertilisers (2015), NGRBA (2016), UNCCD (2016).
• Noise and waste: supersonic jets (1979), 100 dB (2000), Solid Waste Management Rules 2016 (2019). Learn Table 9.1 and Table 9.2 thoroughly, and the Beyond-NCERT standards.

Mains — where it appears and how to answer

• GS1: Delhi's air pollution (2015), labour migration trends (2015), desertification without climate boundaries (2020). GS3: solid and toxic waste disposal (2018), WHO air quality guidelines and NCAP (2021), photochemical smog (2022), solid waste management with Delhi and Indore (2026).
• Related questions already covered elsewhere: Namami Gange and Ganga pollution — Chapter 4; urbanisation problems and segregation — Chapter 2; disasters — Class 11 Chapter 6.
• Answer frame: define → sources (Table 9.1) → spatial pattern (Table 9.2 stretches, metros vs small towns) → effects (health, ecology, economy) → case study (Daurala, Jhabua, Ramesh, Dharavi) → policy (Namami Gange, SBM, NCAP, SWM Rules, watershed programmes) → people's participation and polluter pays.
• Draw the river-strip, acid-rain pathway, waste flow or slum cycle — schematic, without an outline of India.

Tap an option. NCERT's own exercise questions come first; the rest test the figures and common confusions.

Open any question to attempt it in the Question bank — your attempt is saved to your progress.