Chapter 5: NATURAL CALAMITIES
or vibration in Earth crusts. It is due to release of energy and
active internal dynamism of the earth.
are the most destructive.
1: Japan has frequent earthquakes as it’s located at junction of
plate boundaries like Ocean – Ocean, Ocean – Continental or
Continent – Continent plates.
boundaries lead to earthquakes due to formation of mid ocean
ridge and eruptions.
boundaries create friction of plates and lead to earthquakes.
plates and frequent interaction between them.
due to Mining, building of dams.
of old fractures.
The tsunami waves are
created due to the energy released from plate collision.
The colliding energy is transmitted to the waves. These waves
have greater wavelength and height when they hit the coast.
The vessels in the
ocean don’t feel the tsunami. Waves also have higher speed.
- Inundation of land. Indian climate where monsoon concentrated
in a few months leads to flooding situation. The reasons of a
flood are heavy rainfall, poor drainage due to topography, cloud
burst, siltation of river bed, landslide in course of river.
induced reasons like deforestation, unplanned settlements,
global warming and melting of glaciers and construction of dams.
on river banks
management and rainwater harvesting
Rainfall is 60 - 75 cm then place is considered as drought
affected. Southern part of Deccan plateau, Western Rajasthan and
Ladakh are considered drought prone as these have 25%
variability of normal rainfall.
India drought is a more complex problem. Drought is due to
inadequate development. It leads to agrarian poverty,
high mortality of infants and mothers.
To resolve drought related problems:
agriculture irrigation facility
status of farmers.
Rain fed areas where agriculture
completely depends on rainfall cover 55% of the country. 50%
of food grains, 90% of pulses / millets and 66% of livestock
population resides here. However, there is low productivity,
high poverty and subsistence farming. 40% of India's B.P.L
population live here.
The following are drought prone
shadow region of western Ghats – don’t receive adequate rainfall
India – high rainfall but overuse and inadequate storage
east India – wettest part of India but no availability of
should be supplemented by alternate income sources
too from animal husbandry, food processing, agro-forestry,
handicrafts and tourism.
availability of alternate income 24*7 electricity,
transportation, connectivity should be ensured.
cash crops are grown in rain fed areas and this should be
changed to less water intensive crops like
millets. Agro practices should be changed like use of drip
irrigation, sprinkler irrigation.
of Drought-resistance variety, Conservation of soil
moisture – mulching, Pre-monsoon ploughing and soil
dressing ,Deep drilling of seed and fertilizers , crop-rotation.
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