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

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

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.

According to the study, nearly 64% of the tehsils experienced an increase in the frequency of heavy rainfall days by 1-15 days per year in the past decade during the southwest monsoon. (ANI)

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).

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.

The CEEW study is based on tehsil level rainfall data utilising the most recent 12-km high-resolution reanalysis data sourced from the Indian Monsoon Data Assimilation and Analysis project (IMDAA) and confirms the findings of IMD’s earlier studies and observations by meteorologists.

According to the study, nearly 64% of the tehsils experienced an increase in the frequency of heavy rainfall days by 1-15 days per year in the past decade during the southwest monsoon.

Rainfall during northeast monsoon which primarily impacts peninsular India, has increased by more than 10% in the past decade (2012-2022) in approximately 80% of tehsils in Tamil Nadu, 44% in Telangana, and 39% in Andhra Pradesh, respectively, the study found.

CEEW has recommended among other strategies, the development of district-level climate action plans incorporating tehsil-level climate risk assessments. In line with the MoEFCC’s 2019 directive, all the Indian States and UTs are revising their State Action Plans on Climate Change (SAPCCs) up to 2030.

“While the current plans focus on district level climate risk analysis, our findings reveal availability of tehsil-level climate information. We recommend developing district-level climate action plans, integrating this information with socioeconomic and sector-specific data for detailed climate risk assessments in critical sectors like agriculture, water, and energy,” the report said.

“It will be crucial to focus on future-proofing the economy against increasingly erratic rainfall patterns. The monsoons impact the food we eat, the water we drink and also our energy transition. CEEW’s study not only maps monsoon variability—both southwest and northeast—over the past 40 years across India, but also provides openly-accessible tehsil-level rainfall information for decision-makers to assess risks at the local level. With increasing extreme weather events, hyper-local climate risk assessments and action plans are the way to go for India to keep leading in climate action and disaster risk reduction. This will help save lives, livelihoods and infrastructure,” said Vishwas Chitale, Senior Programme Lead, CEEW.

The natural variability of Indian monsoons is further influenced by climate change, the report said. Traditionally monsoon-rich regions such as Northeast India, the Indo-Gangetic plains, and the Indian Himalayan region experienced a decrease in the past decade. Conversely, traditionally drier areas, including Rajasthan, Gujarat, central Maharashtra, and Tamil Nadu, witnessed an increase in southwest monsoon rainfall.

“The monsoon rains, by their very nature, exhibit high variability across space and time due to a complex interplay of atmospheric and oceanic processes surrounding the Indian sub-continent. The natural variability is increasing further due to climate change, as we witness hills, cities, districts faced with flash floods, plains with riverine floods, and simultaneously some areas facing the drought. To effectively navigate this rapidly evolving climate risk landscape brought by changing rainfall patterns, the understanding of monsoon variability and its latest trends at granular level is crucial,” M Mohapatra, director general, IMD wrote in his introduction to the report.