Consider the following statements regarding the Southwest Monsoon and rainfall distribution in India:

1.The orographic effect of the Western Ghats causes differential rainfall, with the windward side receiving heavy precipitation while the leeward side remains comparatively dry.

2.The Arabian Sea branch of the monsoon weakens as it moves inland, resulting in decreasing rainfall from the coastal areas towards the interior regions of Peninsular India.

3. Tamil Nadu receives very little rainfall from the Southwest Monsoon due to its location on the eastern side of the Western Ghats, making it a rain shadow region during this season.

Which of the statements given above are correct?

The correct answer is option 4Key Points

• The orographic effect of the Western Ghats leads to heavy rainfall on the windward side, while the leeward side remains dry.
• The Arabian Sea branch of the monsoon loses strength as it moves inland, causing decreasing rainfall from the western coastal areas toward central India.
• Tamil Nadu remains mostly dry during the Southwest Monsoon as it lies on the rain shadow side of the Western Ghats, receiving minimal rainfall.

Important Points

• Orographic Effect on Rainfall in the Western Ghats
  • The Western Ghats act as a barrier, forcing the moisture-laden Arabian Sea winds to rise, cool, and condense, resulting in heavy rainfall on the western slopes.
  • Windward Side (Heavy Rainfall): Kerala, Coastal Karnataka, Goa, and Western Maharashtra receive heavy monsoon rains (over 200 cm annually).
  • Leeward Side (Rain Shadow Region): Interior areas like Pune, Solapur, and Coimbatore receive significantly less rainfall (less than 60 cm annually).
• Weakening of the Arabian Sea Branch Inland
  • As monsoon winds move further inland, they lose moisture and weaken, leading to progressively lower rainfall.
  • Coastal areas (Kerala, Karnataka) receive over 250 cm annually, while regions like Madhya Pradesh and Telangana receive only 80-100 cm.
• Tamil Nadu’s Rainfall Pattern During Southwest Monsoon
  • Tamil Nadu lies on the leeward (rain shadow) side of the Western Ghats, preventing moisture-laden winds from reaching the region.
  • As a result, Tamil Nadu gets less than 50 cm of rainfall during the Southwest Monsoon.
  • Instead, Tamil Nadu receives most of its rainfall during the Northeast Monsoon (October-December), when winds blow from the Bay of Bengal.

Additional Information

• Impact of Monsoon Variability:
  • Strong monsoons lead to floods in Kerala, Assam, and Bihar.
  • Weak monsoons cause drought-like conditions in Maharashtra, Rajasthan, and parts of Karnataka.
• El Niño and La Niña Influence:
  • El Niño weakens the monsoon, reducing rainfall in India.
  • La Niña strengthens the monsoon, increasing rainfall intensity.
  • Western Disturbances Impacting North India:
• These disturbances cause winter rainfall in North India and influence agriculture.