Decline of rainfall in world’s wettest place

Why is it in News?
  • According to analysis of 119 years of rainfall measurements across North East India, we witnessed a decreasing trend in summer rainfall since 1973, including Meghalaya.
  • Decline in rainfall in the last two decades is driven by -
(1) Changes in the Indian Ocean temperature
(2) Conversion of forestlands and vegetation cover to croplands
(3) Changes in moisture transport from the Indian Ocean in the pre-monsoon period
  • We observed shift of the world’s wettest place from Cherrapunji to Mawsynram (separated by 15-km) in recent decades.
  • Mawsynram receives an average annual rainfall of 11,871 mm while Cherrapunji has annual average at 11,430 mm.
  • Rainy season in North-East:
(1) Pre-monsoon and monsoon are the rainy seasons of North East India.
(2) The Bay of Bengal branch of monsoons move north from Bangladesh’s hot and humid floodplains.
(3) It hits the funnel-shaped relief of the Meghalaya hills with deep valleys and gorges.
(4) The steep parallel mountains (Garo, Khasi and Jaintia hills) in Meghalaya block the movement of the clouds to the north.
(5) They are squeezed in through the gorges and then forced to ascend the steep slopes and shed most of their rainfall in the region.
Source: the Hindu

Posted by Jawwad Kazi on 22nd Feb 2021