Geography: Class 12 (Part 2) — Chapter 9: Geographical Perspective on Selected Issues and Problems

Environmental Pollution

Environmental pollution results from the release of substances and energy from waste products of human activities. Pollutants are classified on the basis of the medium through which they are transported and diffused.

Classification of Pollution

Pollution Types	Pollution Involved	Sources of Pollution
Air Pollution	Oxides of sulphur ($SO_2$, $SO_3$), oxides of nitrogen, carbon monoxide, hydrocarbons, ammonia, lead, aldehydes, asbestos, and beryllium.	Combustion of coal, petrol and diesel, industrial processes, solid waste disposal, sewage disposal, etc.
Water Pollution	Odour, dissolved and suspended solids, ammonia and urea, nitrate and nitrites, chloride, fluoride, carbonates, oil and grease, insecticide and pesticide residue, tannin, coliform MPM, sulphates, heavy metals (lead, arsenic, mercury, manganese), radioactive substances.	Sewage disposal, urban run-off, toxic effluents from industries, run-off over cultivated lands, and nuclear power plants.
Land Pollution	Human and animal excreta, viruses and bacteria, garbage, pesticides, fertiliser-residue, alkalinity, fluorides, radioactive substances.	Improper human activities, disposal of untreated industrial waste, use of pesticides and fertilisers.
Noise Pollution	High level of noise above tolerance level.	Aircrafts, automobiles, trains, industrial processing, and advertising media.

Water Pollution

Indiscriminate use of water by an increasing population and industrial expansion has led to the degradation of water quality. When the concentration of suspended particles, organic, and inorganic substances increases, water becomes polluted and the self-purifying capacity of water fails.

Sources of Water Pollution

Natural Sources: Soil erosion, landslides, decay and decomposition of plants and animals.
Human Sources: Industrial effluents, agricultural runoff (fertilisers, pesticides, herbicides), and cultural activities (pilgrimages, religious fairs, tourism).

Pollution in Major Rivers

River and State	Polluted Stretches	Nature of Pollution	Main Polluters
Ganga (Uttar Pradesh, Bihar, West Bengal)	(a) Downstream of Kanpur (b) Downstream of Varanasi (c) Farakka Barrage	1. Industrial pollution from towns like Kanpur 2. Domestic wastes from urban centres 3. Dumping of carcasses	Cities of Kanpur, Prayagraj, Varanasi, Patna, and Kolkata
Yamuna (Delhi, Uttar Pradesh)	(a) Delhi to confluence with Chambal (b) Mathura and Agra	1. Extraction of water by Haryana and UP for irrigation 2. Agricultural run-off 3. Domestic and industrial waste of Delhi	Delhi dumping its domestic waste

Namami Gange Programme

The Union Government launched this initiative with key objectives:

Developing sewerage treatment systems in towns.
Monitoring industrial effluents.
Development of river fronts and afforestation along banks.
Cleaning of the river surface.
Development of Ganga Grams.
Creating public awareness to avoid adding pollutants.

Air Pollution

Air pollution is the addition of contaminants like dust, fumes, gas, fog, odour, smoke, or vapour to the air in substantial proportion and duration that may be harmful to life and property.

Sources and Effects

Sources: Combustion of fossil fuels, mining, and industries releasing oxides of sulphur and nitrogen, hydrocarbons, carbon dioxide, carbon monoxide, lead, and asbestos.
Effects: Respiratory, nervous, and circulatory diseases. It also causes Acid Rain and Urban Smog (smoky fog over cities).

Noise Pollution

Noise pollution refers to a state of unbearable and uncomfortable sound caused by noise from different sources. The level of steady noise is measured in decibels (dB).

Key Characteristics

Sources: Factories, mechanised construction, demolition works, automobiles, aircraft, sirens, and loudspeakers.
Nature: It is location-specific and its intensity declines with increase in distance from the source.

Urban Waste Disposal

Urban areas generate enormous quantities of solid waste, which includes old and used articles like metals, broken glassware, plastic containers, polythene bags, ash, and organic refuse.

Sources and Management

Sources: Household/domestic establishments and industrial/commercial establishments.
Health Hazards: Uncontrolled decomposition creates obnoxious smells and harbours vectors (flies, rodents) carrying typhoid, diphtheria, diarrhoea, malaria, and cholera.
Case Study: Daurala: An NGO-led community initiative near Meerut successfully restored groundwater quality and ecology using rainwater harvesting, desilting ponds, and planting trees under the "Polluter Pays" principle.

Rural-Urban Migration

Population flow from rural to urban areas is driven by push factors (poverty, low job opportunities, high debt) and pull factors (high demand for labor, perceived job opportunities in cities).

Socio-Economic Consequences

Migrants often end up in low-paid, high-risk, unorganised sectors.
The migration stream is dominated by males, leaving spouses behind in rural areas to look after children and the elderly.

Problems of Slums

Slums are residential areas of the least choice, characterised by dilapidated houses, poor hygiene, lack of ventilation, and absence of basic amenities like drinking water, light, and toilets.

Key Issues

High vulnerability to water-borne and airborne diseases.
Socio-economic exclusion, drug abuse, alcoholism, and crime.
Dharavi (Mumbai): Asia's largest slum, characterised by highly congested single-room tenements, narrow alleys, but also thriving informal industries (ceramics, embroidery, leather goods).
Swachh Bharat Mission (SBM): Launched by the Government of India to improve the quality of life in urban slums through sanitation.

Land Degradation

Land degradation is defined as a temporary or permanent decline in the productive capacity of the land, caused by both natural and human-induced processes.

Classification of Wastelands

Natural Agents: Gullied/ravinous land, desertic or coastal sands, barren rocky areas, steep sloping land, and glacial areas.
Natural and Human Agents: Waterlogged and marshy areas, salinity/alkalinity affected lands, and land with or without scrub.
Human Action: Degraded shifting cultivation areas, degraded forests, degraded pastures, and mining/industrial wastelands.

Case Study: Watershed Management in Jhabua

Jhabua district in Madhya Pradesh successfully prevented land degradation and improved soil quality through community participation and watershed management programmes funded by the Ministry of Rural Development. The Bhils community revitalised common property resources by planting trees, fodder grass, and adopting social-fencing.