Geographical Perspective Test - 1

The correct answer is Sulphur Dioxide.

Key Points

• The substance that causes the maximum air pollution is Sulphur dioxide.
  • Sulfur dioxide or sulphur dioxide is the chemical compound with the formula SO₂.
  • It is a toxic gas responsible for the smell of burnt matches.
  • Pungent smelling colourless gas produced from mostly volcanic activities, industrial processes, and production of sulphuric acid.
  • Sulfur dioxide causes a range of harmful effects on the lungs.

Additional Information

•  Pollutants are the substances that cause pollution; air pollution is caused by air pollutants.
• This can be in the form of excessive gases like carbon dioxide and other vapours that cannot be effectively removed through natural cycles, such as the carbon cycle or the nitrogen cycle.
• Carbon monoxide:
  • Carbon monoxide is a colourless, odourless, and tasteless flammable gas that is slightly less dense than air. 
•  Description -
  • Highly toxic, Produced from internal combustion engines due to incomplete combustion, Other sources are volcanoes, forest fires, etc.
    Greenhouse gas.
• Smoke:
  • Smoke is a collection of airborne particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass.
  • It is commonly an unwanted by-product of fires but may also be used for pest control, communication (smoke signals), defensive and offensive capabilities in the military (smoke screen), cooking, or smoking (tobacco, cannabis, etc.).

The correct answer is Salinization.

Important Points

• Soil salinization involves a combination of processes like evaporation, salt precipitation and dissolution, salt transport, ion exchange etc.
• The salt-affected soils contain excessive concentrations of either soluble salts or exchangeable sodium or both to inadequate leaching of base-forming cations.
• The major soil salinity effect on plant growth is tampering with water absorption.

Additional Information

• Convection heat transfer in gases and fluids occurs due to movement in their molecules in which there is the mixing of fluids that occurs.
• The process of heat transfer during the re-entry of satellites and missiles at very high speeds, into the earth’s atmosphere is known as ablation.
• Denudation refers to the wearing down, stripping, and levelling of the earth's surface.

Explanation:

Sanitary landfills:

• This is a method of disposal of municipal solid waste.
• In this method disposal of refuse is being carried out over the low lying area in the layers of approximately 1.5 m thick.
• Each layer after being disposed of is properly compacted and left for at least 7 days before the application of another layer over it.
• This entire process is biological in approach in which decomposition of the organic matter takes place in 3 phases (action by aerobic micro-organisms, action by acid former, action by methane former)
• For optimum decomposition moisture content of the refuse must be greater than 60%.
• This entire process completed within 2-12 months after which the height of the landfill is reduced by 25-40%.
• The only drawback associated with this method is the formation of end products (Carbon-dioxide and methane).
• In order to channelize the flow of the fluids around the fill area sealants maybe apply over the cells.

The correct answer is Option 1.

Key Points

Carbon Footprint:-

• ​A carbon footprint is the total amount of Greenhouse Gases – GHGs (especially carbon dioxide and methane) released into the atmosphere by different human activities.
• Carbon footprints can be associated with an individual, an organization, a product or an event, among others.
• According to the World Health Organization (WHO), a carbon footprint is a measure of the impact people’s activities have on the amount of carbon dioxide (CO2) produced through the burning of fossil fuels and is expressed as a weight of CO2 emissions produced in tonnes.
• The carbon footprint is seen as a subset of the ecological footprint, where carbon footprint deals with resource usage but focuses strictly on the greenhouse gases released due to the burning of fossil fuels, while the latter compares the total resources people consume with the land and water area that is needed to replace those resources. 
• The release of Six Greenhouse gases as recognized by the Kyoto Protocol will be counted in the carbon footprint. The Six GHGs are:-
  • Carbon dioxide (CO₂)
  • Methane (CH₄)
  • Nitrous Oxide (N₂O)
  • Hydrofluorocarbons (HFCs)
  • Perfluorocarbon (PFCs)
  • Sulfur hexafluoride (SF₆)

When the quantity of acids in the raining water is more than the average, then such rain is called 'Acid rain'.

We are aware that normally rainwater has a pH of 5.6.  When the pH of the rainwater drops below 5.6, it is called acid rain.

Acid rain refers to the ways in which acid from the atmosphere is deposited on the earth’s surface. Oxides of nitrogen and sulphur which are acidic in nature can be blown by wind along with solid particles in the atmosphere and finally settle down either on the ground as dry deposition or in water, fog and snow as wet deposition.

Acid rain is a byproduct of a variety of human activities that emit the oxides of sulphur and nitrogen in the atmosphere. As mentioned earlier, burning of fossil fuels (which contain sulphur and nitrogenous matter) such as coal and oil in power stations and furnaces or petrol and diesel in motor engines produce sulphur dioxide and nitrogen oxides.

SO₂ and NO₂ after oxidation and reaction with water are major contributors to acid rain because polluted air usually contains particulate matter that catalyses the oxidation.

2SO₂ (g) + O₂ (g) + 2H₂O (l) → 2H₂SO₄ (aq)

4NO₂ (g) + O₂ (g)+ 2H₂O (l) → 4HNO₃ (aq)

The bad effects of acid rain

• When acid rain falls and flows as groundwater to reach rivers, lakes etc, it affects plants and animal life in the aquatic ecosystem
• Acid rain is harmful to agriculture, trees and plants as it dissolves and washes away nutrients needed for their growth
• It causes respiratory ailments in human beings and animal
• It may also cause corrosion in many buildings bridges, monuments, fencing etc
• It causes irritation in the eyes and skin of human beings
• This rain reduces the lustre of the metals too
• Acid rain damages buildings and other structures made of stone or metal
• The Taj Mahal in India has been affected by acid rain

The correct answer is Mulching.

Confusion Points

• Contour terracing is a most effective mechanical method to control soil erosion.

Key Points

Mulching is the biological process of controlling soil erosion.

• Mulching is a method of using cut leaves, straw, leaf litter etc. to cover the bare soil while still farming and growing crops on it.
• The main objective of mulching is to keep the soil covered while farming it.
• It is effective against the wind as well as water erosion.
• Some plants such as maize, cotton etc are used as ‘mulch’.
• Mulch is the protective layer formed by stubble.
• Mulches reduce soil moisture evaporation and increase the amount of soil moisture by adding organic matter into the soil.

Additional Information

Explanation:

Municipal solid waste:

• Municipal solid waste (MSW) is more commonly known as trash or garbage
• It consists of everyday items we use and then throw away, such as product packaging, grass clippings, furniture, clothing, bottles, food scraps, newspapers, appliances, paint, and batteries.
• It is the non-hazardous solid waste
• It comes from our homes, schools, hospitals, and local councils.

​Note:

The municipal solid waste does NOT normally include Industrial Waste as it may contain chemicals, toxic substances that may be hazardous.

There are different methods of solid waste management. The following are some of the recognized methods:

• Sanitary landfill
• Incineration
• Recovery and Recycling
• Composting

The correct answer is to reduce surface run-off and soil erosion.

Key Points

Terrace farming:

• It is a method of soil conservation that is practised on hilly terrain.
• On steep slopes of a hill, broad flat steps or terraces are built so that level surfaces can be used to cultivate crops.
• They reduce surface runoff and soil erosion. 

Hence, option 1 is the correct answer.

Some other methods of soil conservation are:

• Mulching:
  • A covering of organic materials, such as straw, is applied to the bare ground between plants.
  • It helps to retain soil moisture.
• Rock dam:
  • Rocks are piled up to slow the flow of water.
  • This prevents gullies and further soil loss.
• Contour barriers:
  • Along contours, stones, grass, and soil are used to create barriers.
  • To collect water, trenches are dug in front of the barriers.
• Intercropping:
  • Various crops are cultivated in alternate rows and sowed at different times to protect the soil from rainwash.
• Contour ploughing:
  • Ploughing parallel to the contours of a hill slope creates a natural barrier for water to flow down the slope.
• Shelterbelts:
  • Rows of trees are planted in coastal and dry regions to reduce wind movement and protect soil cover.

• Poverty is a state or condition in which a person or community lacks the financial resources and essentials for a minimum standard of living.
• Poverty means that the income level from employment is so low that basic human needs can't be met.

Key Points 

Migration:

• When people move from one place to another, the place they move from is called the Place of Origin and the place they move to is called the Place of Destination.
• The place of origin shows a decrease in population while the population increases in the place of destination.
• Migration may be permanent, temporary or seasonal.
• It may take place from rural to rural areas, rural to urban areas, urban to urban areas and urban to rural areas.
• Migrants who move into a new place are called immigrants.
• Migrants who move out of a place are called emigrants
• People migrate for a better economic and social life. 
• Migration is caused as a result of poverty and not a cause of poverty.

Additional Information

Causes of Poverty:

Population Explosion: 

• India’s population has steadily increased through the years.
• During the past 45 years, it has risen at a rate of 2.2% per year, which means, on average, about 17 million people are added to the country’s population each year.
• This also increases the demand for consumption goods tremendously.

Unemployment: 

• Unemployment is another factor causing poverty in India.
• The ever-increasing population has led to a higher number of job-seekers.
• This leads to the migration of people from rural to urban areas and working at minimum wage conditions.
• However, there is not enough expansion in opportunities to match this demand for jobs.

Large size of the family: 

• The majority of the big families belong to remote areas and work in the informal economy causes poverty.
• The social customs and traditions are also hindering households to come out of poverty.

Income inequalities:

• Income inequality is the unequal distribution of income and opportunity between individuals or different groups in society.
• Unemployment has forced people to work at minimum wage, especially in the lower section of society. 

Thus, unequal distribution of land is not a cause of poverty in India.

The correct answer is All of the above.

Key Points

• Soil conservation is the prevention of soil loss from erosion or the prevention of decreased fertility caused by acidification, over usage, salinization, or other chemical soil contamination. 
• Causes of Soil Degradation:
  • Soil pollution
  • Soil Erosion
  • Overgrazing
  • Extraction of minerals at a repeated stage
  • Drought
• Soil Conservation Methods:
  • Afforestation
  • Checking Overgrazing
  • Constructing Dams
  • Changing Agricultural Practices
  • Crop Rotation
  • Strip Cropping
  • Use of Early Maturing Varieties
  • Contour Ploughing
  • Terracing and Contour Bunding
  • Plowing the Land in right direction