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

Question 1:

Which one of the following river is highly polluted?

  1. Brahmaputra
  2. Yamuna
  3. Satluj
  4. Godavari

(d) Godavari

Question 2:

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

  1. Conjunctivities
  2. Respiratory infections
  3. Diarrhoea
  4. Bronchitis

(c) Diarrhoea

Question 3:

Which one of the following is the cause of acid rain?

  1. Water pollution
  2. Noise pollution
  3. Land pollution
  4. Air pollution

(d) Air pollution

Question 4:

Push and pull factors are responsible for:

  1. Migration
  2. Slums
  3. Land degradation
  4. Air pollution

(a) Migration

Question 5:

What is the difference between pollution and pollutants?


Pollution is a state of environment which has degraded from it's natural condition or, any unfavorable change in the natural environment can be termed as pollution. You can consider pollution as a process or a state/condition. On the other hand, pollutants are those elements or substances that bring or cause the pollution. Pollutants are the harmful matters like gases, chemicals, etc.

Question 6:

Describe the major sources of air pollution.


Human activities are the main sources of air pollution. Using energy in our homes, industrial activities, transport and farming are the main actions that have been directly linked to emissions. Gases and particles released from cars and other vehicles include a complex mixture of many pollutants. The burning of fossil fuels, such as coal and oil at both power plants and in the home, is also a major source of air pollution. Forest fires and the burning of living, or recently living organisms (biomass), represent a further major source of emissions.

Question 7:

Mention major problems associated with urban waste disposal in India.


Why is the urban waste disposal or serious problem in India? Explain any three reasons.


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

  1. Lack of sewers or other means to dispose off human excretes safely and the inadequacy of garbage collection sources adds to water pollution
  2. The concentration of industrial units in and around urban centres give rise to a series of environmental problem.
  3. The dumping of industrial waste into rivers is a major cause of water pollution.
  4. 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.
Question 8:

What are the effects of air pollution on human health?


Why is are pollution a serious problem in India? Explain one reason.


The effects of air pollution on human health are:

  1. The ozone layer of the atmosphere gets damaged by different types of chemical pollution. The ozone layer is depleted by the chlorofluorocarbon and great shrinkage in the glaciers.
  2. Air pollution results into the spread of diseases related to lungs, skin, and throat, etc.
  3. Accumulation of the 'urban smog' in the major towns and cities by the poisonous gasses prevailing in the atmosphere.
  4. Air pollution also causes acid-rain which damages human health.
Question 9:

Describe the nature of water pollution in India.


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:

  1. Domestic sewage
  2. Industrial wastes
  3. Agricultural activites
  4. Thermal pollution
  5. Marine pollution.
Question 10:

Describe the problems of slums in India.


Describe the three problems of slums in India.


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.

Question 11:

Suggest measures for reduction of land degradation.


Land degradation encompasses the degradation and pollution of soil and vegetative cover. Deterioration in the quality of soil occurs because of (1) soil erosion, (2) reduction in plant nutrients, (3) decline in soil micro-organisms, (4) lack of moisture, (5) concentration of various harmful elements, etc. Erosion is caused by natural and human factors. Deforestation, overgrazing and improper use of land also acclerates soil erosion. It is estimated that 130 million hectares of land are affected by erosion problems in the country. Shifting agriculture alone has affected about 30 million hectares.
Besides erosion, salinisation and flooding caused due to construction of dam, reservoirs, canal and tanks in geologically unsuitable areas, excessive use of canal irrigation and diversion of floodwater in areas of impervious rocks also reduce the potentially of land. Because of over-irrigation, saline and alkaline areas have increased in the northern plains of the country. Irrigation also changes the structure of the soil. Besides, use of chemical fertilisers, pesticides, insecticides and herbicides degrades the soil by destroying their natural, physical, chemical and biological properties. Chemical fertilisers destroy microorganisms of the soil. Steps should be taken to reduce land degradation. Afforestation on hill slopes, checking of grazing should be done. Proper irrigation techniques should be done. The use of fertilisers and pesticides should be reduced.