Of these, 98 districts were facing extreme to severe to moderately dry conditions as on Feb 28, the Met department’s Standardized Precipitation Evapotranspiration Index (SPEI) showed.
“The data is indicative of water stress and faster evaporation because of hotter Feb days, especially in parts of peninsular, central and west India. The effects include crop stress and water shortages as we head further into the summer season. The affected districts include coastal district Palghar, Solapur, Sangli, Pune, Rajkot, Junagadh, Dwarka, Mysore, Ernakulam, Thrissur, Belgaum, Raigad, Ratnagiri, Trivandrum, Madurai and Vellore, among others,” IMD scientist Rajib Chattopadhyay told TOI.
He said another 442 districts have also begun showing dry conditions, including Mumbai, though not as severe as the 98.
“The early onset of dry conditions is a worrying sign. This means that evaporation rates are likely to be even higher in the coming months with above-normal temperatures expected in parts of central and peninsular India. Despite being a coastal district, Palghar has started showing moderately dry conditions because of high day temperatures even in the west coast,” Chattopadhyay said.
The IMD scientist said parts of peninsular India, areas south of Benguluru in Karnataka, western districts of Kerala, parts of Maharashtra and Tamil Nadu were facing water stress due to abnormally high day temperatures.
“High evaporation rate of surface water during dry seasons, such as this one, is strongly temperature dependent, along with high ultraviolet radiation (UV) index. The excessive dryness and high UV index can have health implications too. Compensating the water loss through evaporation in the absence of rainfall is important, but it is not happening now because of the high day temperatures in these parts, contributing to significant water stress,” he said.
IMD’s latest SPEI map shows a majority of districts, even in northwest India as yellow, indicating mildly dry conditions. And several others districts are in maroon, red and orange, signifying extremely, severely and moderately dry conditions, respectively. “Even in parts of northwest India, we have begun seeing mildly dry conditions as early as Feb. With a very hot April expected this season, this condition is likely to get worse in the absence of sufficient pre-monsoon rainfall. Though, it rained in northwest India recently, a few spells of rainfall may not have much of an impact, especially with a hot season ahead,” Chattopadhyay said.
He said water stress indicated more surface dryness, which can impact any sector, including agriculture, dam and canal water levels that may further affect drinking water availability, as well as human health.
He said summer-like temperatures have set in early in parts of south peninsular India and Maharashtra during the last couple of weeks of Feb and March beginning. “In the absence of western disturbances or local factors that cause rainfall during this time in general, the dryness will persist,” he added.