DWQA QuestionsCategory: GS Paper IQ. What are tropical cyclones? Why India’s east coast is more vulnerable than its west coast on account of tropical cyclones? (GS Paper I; Geography, 150 words, 10 marks)
2 Answers
Sanu sarkar answered 4 years ago

Tropical Cyclone-Tropical cyclone is an intense low pressure area of atmosphere in tropical and subtropical waters.The pressure increases from the centre to the outwards of tropical cyclones.
Reasons of tropical cyclone is more vulnerable in east coast than west coast- 1) Movement-The tropical cyclone that develop in bay of Bengal moves east coast of India under trade winds,on the other hand the cyclone that develop in Arabian sea moves toward Africa.
2) Temperature-The sea surface of Bay of Bengal is comparatively more hotter than Arabian sea which is suitable for development of cyclone.
3) Salinity- The water of bay of Bengal is less saltier than Arabian sea so the water of Bay of Bengal evaporates easily than Arab sea.
4) Location- Typhoon which develops in Pacific Ocean reaches Bay of Bengal without lossing much of energy.
Conclusion-Hence for above mentioned reasons east coast of India is more vulnerable than rest part of India.Amphan,Fani are example of such kind of tropical cyclones.

Nandhini J answered 4 years ago

A cyclone is a low pressure area surrounded by high pressure from all sides,having circular or eliptical shape.
They are clockwise in Northern hemisphere and anticlockwise in Southern hemishpere.
Tropical cyclones
Tropical cyclones are the cyclones that originate over oceans in tropical areas in late summer.
Conditions necessary for the formation of tropical cyclone
1.larger sea surface with the temperature higher than 27°C
2.presence of corriolis force enough to create a cyclonic vortex.
3.A pre-existing week low pressure area.
4.Uniform  wind shear 
5.Upper  troposhperic divergence.
A high humid and ocean temperature of 27°C are contributing factors.
Water evapourtes from the ocean surface and comes into conatct with cold air,forming clouds
A colum of low pressure developes at the centre.winds form around the centre.
As the pressure in the eye weekens,the speed of the wind around it increases.
East coast is more vulnerable than west cost of India 
1.Extension of typhoon
   Typhoons developed in North west pacific that move across South China sea to Bay of bengal without losing its vigour.
   As these cyclones in Bay of bengal,weeken over land after rainfall,the frequency of migration into Arabian sea is low.
3.Increases surface temperature

  • Bay of Bengal has little higher temperature than Arabian sea.
  • Bay of Bengal has a temperature ranging from 22°C -31°C
  • Arabian sea is cooler by 1-2°C than Bay of bengal due to monsoon winds.

4.Bay of Bengal has lesser salinity

  • Since many Indian rivers reach Bay of Bengal,it receives lots of fresh water.
  • But Arabian sea doesnt receive much fresh freshwater from rivers.so its highly saline.

5.Arabian sea is highly evapourative

  • Fresh water is less dense than saline water.
  • Low inflow of fresh water,but high evapouration increases the salinity and density is increased.

Based on above reasons Eastern coast of India faces severe cyclones which cause harm to human life and property.
Fani,Amphan are recent examples of trophical cyclone that attacked eastern coast of India.