NCERT Class 12 Geography of India Chapter 12 Geographical Perspectives on Selected Issues and Problems YouTube Lecture Handouts Part 1

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NCERT Class 12 Geography of India Chapter 12:Geographical Perspectives on Selected Issues & Problems

Title: Geographical Perspectives on Selected Issues and Problems

Rising Pollution

  • Pollution can be classified into
    • air pollution,
    • water pollution,
    • land pollution and
    • noise pollution.

Water Pollution

Higher population and more industrial & urban expansion have suspended particles, organic and inorganic substances. Natural causes include erosion, landslides, decay and decomposition of plants and animals, etc.

Air Pollution

  • Contaminants like dust, fumes, gas, fog, odour, smoke or vapour to the air 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.
  • 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. Cases of Acid Rain - Rainwater analysis of urban environment has indicated that pH value of the first rain after summer is always lower than the subsequent rains.

Noise Pollution

  • Factories, mechanised construction and demolition works, automobiles and aircrafts, etc. There may be added periodical but polluting noise from sirens, loudspeakers used in various festivals, programmes associated with community activities – sound measured in decibels
  • In sea traffic, the noise pollution is confined to the harbor due to loading and unloading activities being carried. Industries cause noise pollution but with varying intensity depending upon the type of industry. Noise pollution is location specific and its intensity declines with increase in distance from the source of pollution.
Rising Pollution
  • Industries produce several undesirable products including industrial wastes, polluted waste water, poisonous gases, chemical residuals, numerous heavy metals, dust, smoke, etc.
  • 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. Fertilizer induces an increase in the nitrate content of surface waters. Cultural activities such as pilgrimage, religious fairs, tourism, etc. also cause water pollution
  • Yamuna pollutants - Extraction of water by Haryana and Uttar Pradesh for irrigation; Agricultural runoff resulting in high levels of micro-pollutants in the Yamuna; Domestic and industrial waste of Delhi flowing into the river
  • Ganga - Industrial pollution from towns like Kanpur; Domestic wastes from urban centres; Dumping of carcasses in the river
  • Water borne diseases like Diarrhoea, intestinal worms, hepatitis etc. are caused by water pollution

Depleting Natural Resources

  • Soil erosion, water-logging, salinization and alkalinization of land lead to land degradation.
  • Land is degraded and productivity declines. Land degradation is generally understood either as a temporary or a permanent decline in productive capacity of the land – can lead to decline in productive capacity of land and conversion to wasteland
  • There are two processes that induce land degradation. These are natural and created by human beings. National Remote Sensing Agency (NRSA) has classified wastelands by using remote sensing techniques and it is possible to categories these wastelands according to the processes that have created them. There are a few types of wastelands such as gullied/ravenous land, desertic or coastal sands, barren rocky areas, steep sloping land, and glacial areas, which are primarily caused by natural agents. There are other types of degraded lands such as waterlogged and marshy areas, land affected by salinity and alkalinity and land with or without scrub, which have largely been caused by natural as well as human factors. There are other types of wastelands such as degraded shifting cultivation area, degraded land under plantation crops, degraded forests, degraded pastures, and mining and industrial wastelands, are caused by human action.

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