NCERT Solutions for Class 12 Geography Ch 12 Geographical Perspective On Selected Issues and Problems

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

(d) Godavari

► (c) Yamuna

(ii) Which one of the following deseases is caused by water pollution?

(a) Conjunctivitis

(b) Diarrhorea

(d) Bronchitis

► (b) Diarrhorea

(iii) Which one of the following is the cause of acid rain?

(a) Water pollution

(b) Land pollution

(d) Air pollution

► (d) Air pollution

(iv) Push and pull factors are responsible for–

(a) Migration

(b) Land degradation

(d) Air pollution

► (a) Migration

2. Answer the following questions in about 30 words.

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

Answer

Pollution	Pollutants
Pollution results from ‘the release of substances and energy from waste products of human activities.	Pollutants are unwanted and harmful substances created due to natural or human activities.
A harbour provides sufficient room for anchorage of ships.	A port is connected with a productive hinterland.

(ii) Describe the major source of air pollution.

Answer

Combustion of fossil fuels, mining and industries are the main sources of air pollution. These processes release oxides of sulphur and nitrogen, hydrocarbons, carbon dioxide, carbon monoxide, lead and asbestos.

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

Answer

The major problems associated with urban waste disposal in India are:

• Solid wastes cause health hazard through creation of obnoxious smell, and harbouring of flies and rodents, which act as carriers of diseases like typhoid, diphtheria, diarrhoea, malaria and cholera, etc.

• The dumping of industrial waste into rivers leads to water pollution.

• In most of other cities and towns about 30 to 50 per cent of the waste generated are left uncollected which accumulate on streets, in open spaces between houses and in wastelands leading to serious health hazards.

• Untreated wastes ferment slowly and release toxic biogas to the atmosphere, including methane.

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

Answer

Air pollution causes various diseases related to respiratory, nervous and circulatory systems. Smoky fog over cities called as urban smog is caused by atmospheric pollution which proves very harmful to human health.

3. Answer the following questions in about 150 words.

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

Answer

Indiscriminate use of water by increasing population and industrial expansion has led degradation of the quality of water considerably.

• Human beings pollute the water through industrial, agricultural and cultural activities. Among these activities, industry is the most significant contributor.

• Industries produce several undesirable products including industrial wastes, polluted waste water, poisonous gases, chemical residuals, numerous heavy metals, dust, smoke, etc.

• Most of the industrial wastes are disposed off in running water or lakes. Consequently, poisonous elements reach the reservoirs, rivers and other water bodies, which destroy the bio-system of these waters. Major water polluting industries are leather, pulp and paper, textiles and chemicals.

• Various types of chemicals used in modern agriculture such as inorganic fertilisers, pesticides and herbicides are also pollution generating components. These chemicals are washed down to rivers, lakes and tanks. These chemicals also infiltrate the soil to reach the ground water.

• Fertiliser induces an increase in the nitrate content of surface waters.

• Cultural activities such as pilgrimage, religious fairs, tourism, etc. also cause water pollution.

(ii) Describe the problem of slums in India.

Answer

Slums are residential areas of the least choice, dilapidated houses, poor hygienic conditions, poor ventilation, lack of basic amenities, like drinking water, light and toilet facilities, etc.

• Open defecation, unregulated drainage system and overcrowded narrow street patterns are serious health and socio-environmental hazards.

• Also, most of the slum population works in low-paid, high risk-prone, unorganised sectors of the urban economy.

• Consequently, they are the undernourished, prone to different types of diseases and illness and can not afford to give proper education to their children.

• The poverty makes them vulnerable to drug abuse, alcoholism, crime, vandalism, escapism, apathy and ultimately social exclusion.

(iii) Suggest measures for reduction of land degradation.

Answer

Land degradation is either as a temporary or a permanent decline in productive capacity of the land There are two processes that induce land degradation. These are natural and created by human beings.

Some measures for reduction of land degradation:

• Deforestation and indiscriminate cutting of trees have resulted in the erosion of topsoil thus, reforestation are helpful in controlling soil erosion and reduce land degradation.

• Changing cropping patterns: Crop Rotation in which cultivated crops are sown in alternative strips to prevent water movement. These are helpful in maintaining the soil quality during the off-season periods of the main crop.

• Farming Practices: Crop Rotation in which cultivated crops are sown in alternative strips to prevent water movement. Strip farming in which cultivated crops are sown in alternative strips to prevent water movement, terrace farming in which flat areas out of a hilly or mountainous landscape are cut in order to grow crops are some of the ways through which we can control land degradation.

• Stabilization of sand dunes by planting thorny bushes.

• Proper discharge of industrial effluents and wastes after treatment.

• Reducing the use of chemical fertilisers and pesticides.

Short Answer Type Questions

Question 1.

Describe the effects and remedies for air pollution.

Answer:

Effects of Air Pollution:

It causes various respiratory diseases like asthma, sore throat, sneezing, allergic rhinitis, smoky fog over the cities commonly known as smog prevails which may lead to accidents.
Air pollution also causes acid rain.
It leads to global warming which creates variation in the rhythmic cycle of seasons.
Depletion of the ozone layer is the result of excessive chlorofluorocarbons and carbon dioxide in the atmosphere.
It is also responsible for the various skin diseases like, itching of eyes, pimples, etc.

Measures to curb Air Pollution:

Promote afforestation
Use electrical appliances with four star or five star ratings.
Use CNG for automobiles.
Proper chimney should be installed.

Question 2.

Describe the sources of air pollution in India.

Answer:

Air Pollution: Increased concentration of contaminants like dust, fumes, gas, odour and smoke in the air causes pollution. This concentration may be harmful to flora, fauna and to property.

Sources of Air Pollution:

Increased use of variety of fuels such as coal, petrol and diesel.
Increased emission of toxic gases from industrial activities into the atmosphere.
Mining activities release the dusts which pollute the air.
Important pollutants are oxide of sulphur and nitrogen, hydrocarbons, carbon dioxide, carbon monoxide, lead andasbestos

Question 3.

What are the sources of pollution in the Ganga and the Yamuna? Also give its polluted stretch.

Answer:

Sources of pollution in Ganga and Yamuna:

Domestic and industrial effluents.
Dumping and carcasses in the river.
Domestic waste from urban centres.
Agricultural run-off.
Extraction of water for irrigation purpose.
Industrial pollution in the cities like Kanpur, Agra, Mathura, Varanasi and Delhi. The polluted stretch of the river Ganga: Downstream of Kanpur, Varanasi, Farakka barrage. The polluted stretch of the riVer Yamuna: Delhi, Mathura and Agra.

Question 4.

Which problems have arisen due to increasing urban population?

Answer:

Some problems have arisen due to increasing urban population:

Congestion
Overcrowding
Inadequate facilities to support the fast growing population and consequent poor sanitary conditions and foul air.
Environmental pollution by solid wastes has now got significance because of enormous growth in the quantity of wastes generated from various sources,
Urban waste disposal.
Increasing number of slums.

Question 5.

Urban waste disposal is a serious problem in India. Why?

Answer:

In metropolitan cities like Mumbai, Kolkata, Chennai, Bangalore, etc. about 90 per cent of the solid waste is collected and disposed. But in most of other cities and towns in the country, about 30 to 50 per cent of the waste generated are left uncollected which accumulate on streets, in open spaces between houses and in wastelands leading to serious health hazards. These wastes should be treated as resource and utilized for generating energy and compost. Untreated wastes ferment slowly and release toxic biogas to the atmosphere, including methane.

Question 6.

Write a note on the life of people living in slums.

Answer:

Slums are residential areas of the least choice, dilapidated houses, poor hygienic conditions, poor ventilation, lack of basic amenities like drinking water, light and toilet facilities, etc. Most of the slum population works in low paid, high risk- prone, unorganized sectors of the urban economy. Consequently, they are the undernourished, prone to different types of diseases and illness and can ill afford to give proper education to their children. The poverty makes them vulnerable to drug abuse, alcoholism, crime, vandalism, escapism, apathy and ultimately social exclusion.

Question 7.

What are the main sources of noise pollution?

Answer:

The main sources of noise pollution are various factories, mechanized construction and demolition works, automobiles and aircraft’s, etc. There may be added periodical but polluting noise from sirens, loudspeakers used in various festivals, programmes associated with community activities.

In sea traffic, the noise pollution is confined to the harbour due to loading and unloading activities being carried. Industries cause noise pollution but with varying intensity depending upon the type of industry.

Question 8.

Why are rural areas important for urban centers?

Answer:

Rural areas are important for urban areas because they provide labour for industrial development and for tertiary activities. At present, 47 per cent of the world’s six billion population lives in cities and more will join them in near future. This proportion is estimated to go up to 50 per cent by 2008. By 2050, an estimated two-thirds of the world’s population will live in urban areas, imposing even more pressure on the space infrastructure and resources of cities, which are manifested in terms of sanitary, health, crime problems and urban poverty.

Long Answer Type Questions

Question 1.

The largest slum Dharavi exhibits many contradictory elements. What are these? Explain.

Answer:

Dharavi is Asia’s largest slum. There are many contradictory elements.

Negative versus positive aspect of the slum:

Only one main road traverses the slum, the miscalled ‘ninety-foot road’, which has been reduced to less than half of that for most of its length.
Some of the side alleys and lanes are so narrow that not even a bicycle can pass. The whole neighborhood consists of temporary buildings, two or three storeyed high with rusty iron stairways to the upper part, where a single room is rented by a whole family, sometimes accommodating twelve or more people.
On the one hand, in this place of shadowless, treeless sunlight, uncollected garbage, stagnant pools of foul water, where the only non-human creatures are the shining black crows and long grey rats, on the other hand, some of the most beautiful, valuable and useful articles in India are made. From Dharavi come delicate ceramics and pottery, exquisite embroidery and zari work, sophisticated leather goods, high-fashion garments, finely-wrought metalwork, delicate jewellery settings, wood carvings and furniture that would find its way into the richest houses, both in India and abroad.

Question 2.

State any four pressing environmental concerns of India.

Answer:

Four pressing environmental concerns in India are:

Water Contamination: In India drinking water is getting contaminated due to industrial waste. It is leading to water¬borne diseases.
Air Pollution: Due to urbanisation, the number of vehicles on Indian roads is increasing continously. Number of motor vehicles has increased from 3 lakh in 1951 to 67 crores in 2003. India is one of the ten most industrialised nations of the world but it has happened at the cost of environment which is irreversible.
Deforestation: India’s forest cover is dwindling continuously due to increasing demand by increasing population. It is increasing air pollution and the problems associated with it. Per capita forest land in India is only 0.08 hectare against a requirement of 0.47 hectare.
Land Degradation: Land degradation is happening because of loss of vegetation occurring due to deforestation, unsustainable fuel wood and fodder extraction, encroachment into forest lands, non adoption of adequate soil conservation measures, indiscriminate use of chemicals, improper planning and management of irrigation system. Certainly, correction of environmental degradation involves an opportunity cost in the form of adverse health conditions, poor quality of life in poor environmental conditions and expenditure by government on correcting the harm done by environment.