Natural Disasters - Indian Geography, UPSC, IAS. | Geography (Prelims) by Valor Academy PDF Download

Natural Disasters

Natural Disasters

Types

• Earthquakes
• Tsunami
• Cyclones
• Floods
• Droughts

Earthquakes

• Mainly caused by tectonic movements which were discussed in “Basics of Geography”
• Indian has been divided into five earthquake zones:
  • Very high damage risk zone
  • High damage risk zone
  • Moderate damage risk zone
  • Low damage risk zone
  • Very low damage risk zone

Effects of earthquake

• Damage and destruction of settlement, industry , infrastructure
• It renders people homeless
• Landslides, sometime resulting into floods
• Tsunami

Mitigation

• Establishing earthquake monitoring centres
• Preparing a vulnerability map of the country
• Modifying house types and building designs

Tsunami

Tsunami

• Tsunami is a Japanese word which means sea-waves
• Earthquakes and volcanic eruptions that cause the sea-floor to move abruptly resulting in sudden displacement of oceanic water in the form of high vertical waves are called tsunami
• The speed of the waves depends on the depth of water

• It is more in the shallow than in the deep water
• So the impact of the Tsunami is less in the ocean than in the shallow water near the coasts
• In the deep sea  the Tsunami has a very long wave-length and limited wave height
• As against it the wave height increases in shallow water

Areas of occurrence

• Tsunamis are frequently observed along the Pacific ring of fire, coasts of Alaska, Japan, Philippines and other islands of Southeast Asia, Indonesia, Malaysia, Myanmar, Sri Lanka and India etc.

Effects & Remedies

• The energy stored in water destroys settlements, buildings results in the loss of life and property.
• It result in spread of diseases
• It is beyond the capacity of govt. to mitigate the damage.
• Early warning is the only way to deal with it.

Floods

Causes

• Storm surge in coastal areas
• High intensity rainfall for long period
• Poor drainage due to silting of rivers

Besides, human activities like deforestation, colonisation of flood plains play an important role in increasing the intensity of floods

Control of floods

• Construction of river embankment
• Construction of dams
• Afforestation
• Marking of flood zones
• Establishment of cyclone centres in coastal areas

Droughts

• It is applied to a period when there is a shortage of water availability due to inadequate precipitation, excessive evaporation and over utilisation of water
• In India nearly 19% of the area suffers fron drought

Drought Phone Areas

Consequences of drought

• Crop failure leading to scarcity of foodgrains
• Shortage of water
• Large scale death of cattle and other animals
• Spread of many waterborne disease

Remedy

• Identification of ground water potential in the form of aquifers
• Transfer of river water from surplus to deficit area
• Construction of reservoirs and dams
• Dissemination of knowledge about drought resistant crops
• Rainwater Harvesting can also be effective