NCERT Solutions for Class 12 Geography Part B Chapter 12 Geographical Perspective on Selected Issues and Problems

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NCERT Solutions for Class 12 Geography Part B Chapter 12 Geographical Perspective on Selected Issues and Problems

Q1. 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


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

(a) Conjunctivitis
(b) Diarrhorea
(c) Respiratory infections
(d) Bronchitis

Answer:- (b) Diarrhorea


(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


(iv) Push and pull factors are responsible for-

(a) Migration
(b) Land degradation
(c) Slums
(d) Air pollution

Answer:- (a) Migration


Q2. Answer the following questions in about 30 words.

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

Answer:- Pollution: Contamination of air, water, environment due to increase in contaminants beyond permissible limits or deterioration of quality of land leading to a fall in its quality and purity is called pollution.
Pollutants: Those elements whose addition to environment in excess results in deterioration of the quality of land, air or water are called pollutants. Some examples of pollutants are
radioactive elements, carbon monoxide, solid waste, acids, etc.


(ii) Describe the major source of air pollution.

Answer:- Air pollution is the addition of contaminants, like dust, smoke to the air beyond the permissible limit. Major source of air pollution include coal combustion, fly ash, soot production, vehicular pollution, factory pollution, discharge of untreated solid waste and sewage, unsustainable development, deforestation, natural sources include wildfires, volcanic eruptions, dust storms etc. Further combustion of fossil fuels, unsustainable mining and unchecked industrial development also lead to degradation in air quality. These processes release oxides of Sulphur and nitrogen, hydrocarbons, carbon dioxide, carbon monoxide, lead and asbestos which stay in the environment for long periods and cause disastrous impact health, wildlife and environment.


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

Answer:- The problems of urban waste disposal in Indian cities are as follows :

Lack of sewers or other means to dispose off human excretes safely and the inadequacy of garbage collection sources adds to water pollution
The concentration of industrial units in and around urban centres give rise to a series of environmental problem.
The dumping of industrial waste into rivers is a major cause of water pollution.
The solid waste generation continues to increase in both absolute and per capita in terms in cities. The improper disposal of solid waste attracts rodents and flies which spread diseases.

Major problems associated with urban waste disposal in India :-
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 household wastes are disposed off either on public lands or on private contractors’ sites, Smoky fog over cities called as urban smog is caused by atmospheric pollution. It proves very harmful to human health. Air pollution can also cause acid rain.
These wastes cause frequent nuisance as and when these are carelessly handled, spread by
wind and splintered through rain water.


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

Answer:- Air pollution causes various diseases related to the respiratory, nervous and circulatory systems. Immediate effects include watery eyes, coughing, inflammation and difficulty in breathing. Long term exposure could result in asthma, lung cancer, psychological complications, autism, fetal growth, and low birth weight. It is increasingly becoming a major threat to health and well-being.


Q3 Answer the following questions in about 150 words.

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

Answer:- Water pollution. Water is another indispensable source of our life. Pollution of water has caused far reaching implications. It is a serious problem in metropolitans like Delhi, Kolkata and Mumbai. It not only affects the water of rivers, tanks and lakes; but also the ocean water. The following factors affect water pollution:
Domestic sewage
Industrial wastes
Agricultural activites
Thermal pollution
Marine pollution.


(ii) Describe the problems of slums in India.

Answer:- Problems of Slums and Urban Waste. Many problems have arisen due to increasing population and urbanisation. The problem of slums and disposal of urban waste are the two main issues. Slums. There is shortage of space in towns. The increasing population creates housing problems. Multi-storeyed buildings are being constructed to solve it. Generally, push and pull factors force the people to migrate to towns. These people move in search of employment in towns.

In towns, the housing facility is costlier due to which poor people construct huts on the vacant land outside the towns. This is how the slums begin to develop. There is dense population in such slums and no facility for water-drainage and disposal of urban waste. People’s standard of living is very low. The administration has taken many steps to provide facilities to these areas, yet these slums suffer from many diseases.


(iii) Suggest measures for reduction of land degradation.

Answer:- The pressure on agricultural land increases not only due to the limited availability but also by deterioration of quality of agricultural land. Soil erosion, waterlogging, salinisation and alkalinisation of land lead to land degradation.

Various measures for reduction of land degradation are :-

➔ Reduce all activities that cause land degradation such as deforestation, overgrazing,
improper agricultural activities, mining, etc.
➔ Soil erosion can be prevented by Afforestation- Areas prone to soil erosion can be planted
with trees that have high soil binding capacity.Degraded lands around you can be improved by
creating lawns and planting small plants and Reforestation- This can help in reclaiming the land before it is completely lost.
➔ Agricultural contributes the largest share of losses of valuable land. Following agricultural practices can help in preventing degradation of land :-
➔ Terrace farming- This method of farming is done in areas of steep slopes. It acts as a break for flowing water, and consequently reduces the speed of flow. It helps in preventing rill and gully erosion


Extra Questions of NCERT Solutions for Class 12 Geography Part B Chapter 12 Geographical Perspective on Selected Issues and Problems

Q1. Name any two natural sources of water pollution.

Answer:- Landslides and decay and decomposition of plants and animals are natural sources of water pollution.


Q2. Name any two diseases that are caused by air pollution.

Answer:- Lung cancer and asthma are two diseases caused by air pollution.


Q3. Which source of pollution is responsible for acid rains.

Answer:- Air pollution is responsible for acid rains. It is caused by a chemical reaction that begins when compound like sulphur dioxide and nitrogen oxides are released into the air in the atmosphere. They mix and react with water molecules and oxygen to form acidic rain.


Q4. Name two metropolitan cities which are the main polluters of river Ganga before it reaches Varanasi.

Answer:- Kanpur and Allahabad are the two metropolitan cities which are the main polluters of river Ganga before it reaches Varanasi.


Q5. Which city is the main polluter of river Yamuna?

Answer:- The city which is the main polluter of river Yamuna in Delhi.


Q6. Which is the main source of environmental pollution in India?

Answer:- Industries are the main source of environmental pollution in India.


Q7. What do you mean by water pollution?

Answer:- Deterioration in quality of water due to presence of waste, toxic chemicals, etc. water becomes unfit for use. They are difficult to remove by standard purification measures. Flourides, e-coli from wastes are examples of water pollution.


Q8. What are the main sources of water pollution? .

Answer:- Water pollutants are created by natural sources like soil erosion, landslides, decay and decomposition of plants and animals, etc. But the main pollutants come from human sources which includes polluting the water through industrial, agricultural and cultural activities. Human causes are the real causes of concern.


Q9. What is meant by air pollution?

Answer: Air pollution is taken as 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 flora and fauna and to property.


Q10. Name the diseases caused by air pollution.

Answer:- 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.


Q11. What do you mean by noise pollution?

Answer:- Noise pollution refers to the state of unbearable and uncomfortable to human beings which is caused by noise from different sources. The level of steady noise is measured by sound level expressed in terms of decibel (dB).


Q12. Which physical disorders take place due to noise pollution?

Answer:- Hearing problems, headache, anxiety, irritation, depression, digestive disorder, etc.


Q13. What health problems are caused by solid waste?

Answer:- 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.


Q14. How do industries pollute India’s water bodies? Explain with examples.

Answer:- Wastewater, poisonous gases, chemical residuals, numerous heavy metals, dust, smoke, etc from industries contribute to water pollution. During the last fifty years, the number of industries in India has grown rapidly. But water pollution is concentrated within a few sub-sections, mainly in the form of toxic wastes and organic pollutants.
Most of these defaulting industries are leather, pulp and paper, textiles, chemicals, sugar mills, distilleries and thermal power stations. Not all industries have treatment facilities for industrial effluents. As small scale industries cannot afford enormous investments in pollution control equipment as their profit margin is very slender.


Q15. Name the Industrial wastes causing water pollution.

Answer:- Though water pollutants are also created from natural sources (erosion, landslides, decay and decomposition of plants and animals, etc.) pollutants from anthropogenic sources are the real causes of concern. They include industrial sources, urban source, agricultural source, cultural source, etc.
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. Consequently, poisonous elements reach the reservoirs, rivers and other water bodies which destroy the biosystem of these waters. Major water polluting industries are leather, pulp and paper, textiles and chemicals.


Q16. How is air pollution harmful ? Explain any three different causes of air pollution.

Answer:- Air pollution is harmful. Air pollution results into the spread of diseases related to lungs, skin and throat etc. Air pollution also causes acid rain which damages human health. The ozone layer is depleted by the chlorofluorocarbon and great shrinkage in the glacier.
Causes of air pollution:
(i) Natural Resources: Such as volcanic eruption, dust, strom, fires etc.
(ii) Factories: Factories cause smoke, ash.
(iii) Automobiles: Automobilies release carbon monoxide & lead in the atmosphere. Transport and farming are the main actions that have been directly linked to emissions. Forest fires and the burning of living, or recently living organisms, represent a further major sources of emission.


Q17. Name the diseases caused by air and water pollution.

Answer:- Air pollution causes diseases of lungs, heart, nervous and circulatory systems. A study conducted in the ambient air of Kolkata (in 1994) concluded that three out of every ten persons in the city suffered from some kind of respiratory diseases that cough, bronchitis and allergic-rhinitis which were associated with concentrations of suspended particulate matter.
The diseases commonly caused due to contaminated water are diarrhoea, trachoma, intestinal worms, hepatitis, etc. Recent World Bank and World Health Organisation data shows that about one-fourth of the communicable diseases in India are water-borne.


Q18. Describe the major problems I associated with urban water disposal in India.

Answer: Urban Waste Disposal Problems. The environmental problems of cities include water, air and noise pollution and disposal of toxic and hazardous wastes.
Problems. Lack of sewers or other means to dispose off human excretes safely and the inadequacy of garbage collection services adds to water pollution because many of the uncollected wastes are washed into streams. The dumping of industrial waste into rivers is a major cause of industrial waste into rivers is a major cause of water pollution. River pollution from city-based industries and untreated sewage leads to serious health problems downstream.
Increase in urban wastes.
Solid waste generation continues to increase in both absolute and per capita terms in cities. It is estimated that per capita waste generation increased from 375 gm/day to 490 gm/day during 1971-1997 in urban areas of the country. This increase along with the population increase has tremendously swollen up the figuers of total waste generation quantum. The amount of total wastes has increased from 14.9 Tonnes per day to 48. Tonnes per day.

III effects of urban waste : At the same time, the composition of solid waste changes from biodegradable organic material to plastic and other synethetic materials, which take much longer time to decompose. When this solid waste is not collected and disposed off efficiently and effectively, it attracts rodents and flies which spread diseases. It also pollutes and degrades land and water resources.


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