Watershed study highlights shifting monsoon patterns by analysing over 40 yrs of rain data

A new study has shown that more than half of India’s administrative units (or tehsils) saw an increase in monsoon rainfall in the 2012-22 decade over the 30-year, 1982-2011 baseline; 11% of key agricultural hotspots saw a decline; and almost two-thirds witnessed an increase in the frequency of heavy rainfall.

- Jayashree Nandi

Majority of India's tehsils saw increase in rain in 2012-22: Report

The results of the large-scale study, “Decoding India’s Changing Monsoon Patterns”, by the Council on Energy, Environment and Water (CEEW) , provide a granular picture of the changing and erratic monsoon patterns in India.

According to the study, around 55% of India’s 4000-plus tehsils have witnessed an increase in monsoon rainfall in the past decade (2012-22) by at least 10%, compared to the climatic baseline (1982–2011).

Most of this increase was recorded in the traditionally drier regions of Rajasthan, Gujarat, central Maharashtra, and parts of Tamil Nadu.

HT reported on March 31, 2020 that an India Meteorological Department study found a significant increase in heavy rainfall (6.5 cm or more) days in Gujarat’s Saurashtra and arid regions of Kutch and south-eastern Rajasthan, as well as northern Tamil Nadu, northern Andhra Pradesh which are otherwise considered arid regions. The study also found a decrease in rainfall over the years in states in the Gangetic basin. CEEW found that nearly 11% of Indian tehsils witnessed a decrease in the past decade (2012-2022) by at least 10% compared to the climatic baseline, and that these were regions in the Indo-Gangetic plains, which contribute to more than half of India’s agricultural production, northeastern India, and the Himalayas.