Sudden movement or vibration in Earth crusts. It is due to release of energy and active internal dynamism of the earth.
Shallow focuses are the most destructive.
Fig 1: Japan has frequent earthquakes as it’s located at junction of three plates.
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.
Floods – 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.
Human induced reasons like deforestation, unplanned settlements, global warming and melting of glaciers and construction of dams.
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.
In 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:
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 areas:
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Q1:Origin of the earthquake is the
Q2:Most destructive earthquakes are
Q3:Reasons for earthquakes include
Q4:reasons for floods include
Q5:The following are drought prone areas