What is the Indian monsoon?
- The southwest monsoon is a summertime reversal in wind direction that provides nearly 70% of the Indian subcontinent’s annual rainfall.
- Monsoon winds originate from the southern Indian Ocean. They get deflected southwestwards towards India after crossing the equator. These winds are driven by air pressure differences caused by the more rapid heating up of the land in summers compared to the ocean. The land heats up the air over it, causing it to rise and create a low-pressure zone, which attracts winds from the high pressure regions over the ocean.
- In south Asia, the effect is enhanced by the Tibetan plateau, which heats up more than the atmosphere would at its height.
- Monsoon has a set pattern of advance and withdrawal. It arrives in southern India in May or June, and advances northwards and westwards, reaching Pakistan by July. It retreats from Pakistan by September, finally withdrawing from southern India by December.
- The season doesn’t see a continuous deluge, but has alternate wet and dry phases, the timing and duration of which account for much of the year-to-year variation in monsoon rains.
How does the monsoon affect India’s economy?
- The monsoon’s failure is often linked to the economy’s overall performance.
- It is not the agricultural sector alone that is affected by a bad monsoon, industry too suffers as lower farm output decreases demand from this sector, which employs half the country’s workforce.
- Contrasting GDP growth rates with drought years since 1951-52 reveals growth is sluggish in drought years. In recent years this correlation has become weaker, which may be linked to the fact that agriculture’s share in GDP has also fallen. But it continues to employ half of India’s workforce.
Is there a major difference between agricultural output in Kharif and Rabi seasons?
- Over the past decade, the share of Kharif (monsoon) crops in the national output have fallen, while Rabi (winter) crops are on the rise.
- Crops like rice and maize, which grow in monsoon and winter, have seen a marked decline in Kharif output, while the share of their Rabi output has risen. Exclusively Rabi crops, such as wheat, remain unaffected by monsoons.
What are the country’s wettest and driest states?
- Mawsynram, a village in Meghalaya is the world’s wettest place.
- Meghalaya receives the country’s highest rainfall followed by Goa and Sikkim.
- Rajasthan and Haryana are among India's driest states