Question

Chirrapunji receives maximum rainfall in the world. (Give the reason)

Answer 1

Cherrapunji is located at 25.30°N 91.70°E. It has an average elevation of 1,484 metres (4,869 ft) and sits on a plateau in the southern part of the Khasi Hills, facing the plains of Bangladesh. The plateau rises 600 meters above the surrounding valleys. Cherrapunji receives both the southwest and northeast monsoonal winds, giving it a single monsoon season. It lies on the windward side of the Khasi Hills, so the resulting orographic lift enhances precipitation. In the winter months it receives the northeast monsoon showers that travel down the Brahmaputra valley.

Cherrapunji receives rains from the Bay of Bengal arm of the Indian summer monsoon. The monsoon clouds fly unhindered over the plains of Bangladesh for about 400 km. Thereafter, they hit the Khasi Hills which rise abruptly from the plains to a height of about 1370 m above mean sea level within 2 to 5 km. The geography of the hills with many deep valleys channels the low-flying (150–300 m) moisture-laden clouds from a wide area to converge over Cherrapunji. The winds push the rain clouds through these gorges and up the steep slopes. The rapid ascent of the clouds into the upper atmosphere hastens the cooling and helps vapours to condense. Most of Cherrapunji's rain is the result of air being lifted as a large body of water vapour. The extreme amount of rainfall at Cherrapunji is perhaps the best-known feature of orographic rain in northeast India.

The major part of the rainfall at Cherrapunji can be attributed to the orographic features. When the clouds are blown over the hills from the south, they are funneled through the valley. The clouds strike Cherrapunjee perpendicularly and the low flying clouds are pushed up the steep slopes. It is not surprising to find that the heaviest rainfalls occur when the winds blow directly on the Khasi Hills.

It holds two Guinness world records for receiving the maximum amount of rainfall in a single year: 22,987 millimetres (905.0 in) of rainfall between August 1860 and July 1861 and for receiving the maximum amount of rainfall in a single month: 9,300 millimetres (370 in) in July 1861.