Decreasing Rainfall Trend in Wettest place of Earth

In Context: A recent study that looked at the rainfall pattern in the past 119 years found a decreasing trend at Cherrapunji and nearby areas.

• Cherrapunji was previously the wettest place on earth but now Mawsynram is the wettest place in the world. Mawsynram receives over 10,000 millimetres of rain in a year.

Key Highlights

• Decrease in trend of rainfall: The study highlighted that the rainfall pattern in the past 119 years (period of 1901–2019) found a decreasing trend at Cherrapunji and nearby areas.
  • The study noted that the annual mean rainfall for the period 1973–2019 showed decreasing trends of about 0.42 mm per decade.
• Factors responsible for this trend: The phenomenon is driven by changes in the Indian Ocean temperature and conversion of forestlands and vegetation cover to croplands in the last two decades.
  • Satellite data analysis shows a reduction in the vegetation area in northeast India in the past two decades, implying that human influence also plays an important role in the changing rainfall patterns.
  • The traditional way of cultivation known as Jhum cultivation or shifting cultivation and developmental activities in the region has contributed to deforestation.

What are the major causes of concerns?

• North East India is mostly hilly and is an extension of the Indo-Gangetic Plains, the region is highly sensitive to changes in regional and global climate.
• Northeast India has the highest vegetation cover in India and includes 18 biodiversity hotspots of the world, and thus is important in terms of its greenery and climate-change sensitivity.

Way forward & Conclusion

• Long term data needed: In North East India, long-term, dense and reliable daily rainfall data from IMD is infrequent due to remoteness of the region with low population density, extended periods of regional conflicts.
  • Now, India is planning to set up a Regional Climate Centre for the Third Pole (Himalayan) region during the next five years for weather and climate service up-gradation in the Himalayan region.
• Conservation of biodiversity: There is the need to conserve the vegetation or forest areas in the northeast.
  • Given the climate sensitivity of the region long-term plans for sustainable development are necessary.
• Waste Reduction: Solid waste and waste water management strategies are inevitable to combat climate-induced changes of water bodies and ground water.
• Know about the Rainfall Pattern: A better understanding of the physical mechanisms of the North East India’s rainfall variability is crucial for developing advanced projections of future rainfall variability.

Source: TH