Three places in India emerge as new heatwave hotspots, human population at risk: what it means

Northwest, central and south-central India have emerged as new hotspots of intense heat waves over the past 50 years, a study has found.

The study indicated that climate change and the consequent increase in heat wave trends would put a larger population at risk. The study also underscores the need to develop effective heat action plans in the three regions of the heatwave hotspot, emphasizing the different vulnerabilities of residents.

Researchers analyzed monthly, seasonal and decadal variations as well as long-term trends in heat waves and severe heat waves for the pre-monsoon (March May) and early summer monsoon (June July) between 1951 and 2016.


What is a heat wave?

For the plains, a “heat wave” is declared when the maximum temperature is above 40 degrees Celsius, and at least 4.5 notches above normal. A “severe” heat wave is declared if the deviation from normal temperature is more than 6.5 degrees Celsius, according to the IMD.

Published in the International Journal of Climatology, the study links heat waves to greater concerns for human health, agriculture and the natural ecosystem.

Delhi heatwave

How will this affect humans?

Heat waves have become a deadly health hazard, claiming thousands of lives around the world in recent decades, with episodes increasing in frequency, intensity and duration over the past half-century in India too. This has had serious repercussions on health, agriculture, the economy and infrastructure. In such a scenario, it is extremely important to identify the regions of the country most vulnerable to heat waves in order to prioritize immediate policy intervention and strict mitigation and adaptation strategies, the Department said. science and technology.

The study suggests a way forward to assess climate performance and uncertainty in extreme weather analysis in future projections.

Delhi heatwave

Led by Professor RK Mall of the Mahamana Center of Excellence in Climate Change Research (MCECCR) at the Hindu University of Benares (BHU), the researchers studied changes in the spatial and temporal patterns of heat waves and heat waves severe over the past seven decades.

What did the study find?

They found a change in the heat wave pattern with an upward trend in three major heat wave prone regions in northwest, central and south-central India, the highest being in western Madhya Pradesh.

A significant downward trend has been observed in the eastern region of the Gangetic Plains of West Bengal. The trends are continuously changing in the eastern region of Gangetic West Bengal and Bihar to the northwestern, central and south-central regions of India.

“Research has also observed an alarming southward expansion and spatial increase in severe heat waves in recent decades that could put a larger population at additional risk of heat stress in a region already characterized by low amplitude heat stress. daytime temperature (DTR), or the difference between maximum and minimum temperatures in a day and high humidity,” the Ministry of Science and Technology said in a statement.

Workers drink water to quench their thirst as heat wave grips India

Importantly, heatwave and severe heatwaves were found to be positively correlated with mortality in Odisha and Andhra Pradesh, highlighting that human health is highly sensitive to severe heatwave disasters.

With an ever-increasing extreme temperature threshold, a heat resistant future is the need of the hour. A dense population with an intensive culture of outdoor work calls for equitable heat mitigation and adaptation strategies covering every section of society according to their vulnerability, he said.