NCERT Solutions for Class 12 Geography - 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
Ans: (c)

(ii) Which one of the following deseases is caused by water pollution?
(a) Conjunctivitis
(b) Diarrhorea
(c) Respiratory infections
(d) Bronchitis
Ans: (b)

(iii) Which one of the following is the cause of acid rain?
(a) Water pollution
(b) Land pollution
(c) Noise pollution
(d) Air pollution
Ans: (d)

(iv) Push and pull factors are responsible for–
(a) Migration
(b) Land degradation
(c) Slums
(d) Air pollution
Ans: (a)

Q2: Answer the following questions in about 30 words.
(i) What is the difference between pollution and pollutants?
Ans:

(ii) Describe the major source of air pollution.
Ans: 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.
Ans: 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.
Ans: 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.

Q3: Answer the following questions in about 150 words.
(i) Describe the nature of water pollution in India.
Ans: 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.
Ans: 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.
Ans: 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.