After remaining largely inactive for more than a week, the monsoon finally picked some strength and momentum beginning Monday. Maharashtra, for instance, received its first good rainfall of the season on Tuesday. But the monsoon’s behaviour so far in June has raised concerns that the season might be even drier than predicted.
June was supposed to be among the relatively better rainfall months. The India Meteorological Department (IMD) forecast that while rainfall over India during the entire monsoon season was likely to be 90% of the long-period average, June was expected to get at least 92% of its normal rain.
This was because it was expected to be least affected by the El Niño phenomenon in the equatorial Pacific Ocean, which has a tendency to suppress rainfall over the Indian region. But with barely a week remaining, the June rainfall deficit is more than 40% and appears unlikely to be bridged.
An IMD bulletin on Wednesday forecast low to moderate rainfall activity in the areas covered by the monsoon — which is only around half of the country’s landmass. Around this time in June, the monsoon normally covers almost the entire country.
Not El Niño yet
Though the El Niño phase of the equatorial Pacific Ocean, off the northwestern coast of South America, has been declared to have emerged, this has not been the reason for the large rainfall deficit in June so far. This is because the effects of El Niño, or the opposite La Niña phase, on the Indian monsoon comes with a lag. It usually takes more than a month for the complete effects of El Niño to become evident over the Indian region.
IMD director general Mrutyunjay Mohapatra said the El Niño phenomenon had a very small role to play in the monsoon performance in June. “El Niño emerged around the first week of June. We are now beginning to see its impact on the monsoon. It is not that there is no impact. But it is not the main reason for the rainfall deficit in June,” Mohapatra said.
He identified other reasons — low pressure systems of inadequate strength; weak monsoon currents; and the unfavourable phase of a moving wind and cloud system called Madden Julian Oscillation, or MJO.
Like El Niño, MJO is an ocean-atmosphere interaction that influences weather events across the world, though only over a short term. But while the El Niño phenomenon plays out in the Pacific Ocean, MJO is a moving system of winds and clouds. The system engulfs the entire equatorial region like a ring but moves in an eastward direction. It helps bring rain in some regions but suppresses it in others. As it keeps moving, the areas where it brings rainfall keep changing.
During June, the rain-bearing part of MJO was located far from the Indian region. The part of the MJO system that was around the Indian region was suppressing rainfall. But that is changing now.
“Through most of June, the MJO was in an unfavourable state for us. But it is moving and it is expected that the favourable part of MJO would be over the Indian region around the first week of July. We can expect some good rainfall around that time,” Mohapatra said.
As of now, the monsoon getting active again is a big relief, but the effects of El Niño will also become progressively stronger. As of now, almost 75% of the country’s land area has more than 20% rainfall deficiency.
Reducing monsoon dependence
Historically, India’s dependence on the monsoon rainfall has been very high. The four-month long rainy season accounts for about 75% of India’s annual rainfall.
This water is critical for irrigation, recharging groundwater, replenishing natural water bodies such as rivers and lakes, generating hydropower, and maintaining reserves in reservoirs. A bad monsoon would lower agricultural productivity, affect power generation, threaten food security, reduce farm incomes, suppress rural demand and dampen overall economic growth. The last time when India faced a particularly bad monsoon, trains had to be engaged to transport drinking water to extremely dry regions.
Over the years, however, efforts have been made to reduce India’s dependence on the monsoon. Though the land under irrigation has not changed substantially, there have been improvements on other fronts. A bulk of the work under the rural employment scheme has been aimed at developing infrastructure related to rainwater harvesting, water storage and conservation. Official reports show an improvement in groundwater situation in the last few years. The emergence of solar and wind electricity has reduced reliance on hydropower.
“We would still need to plan and intervene effectively, but our ability to absorb and deal with the stress has certainly improved. The impact of a bad monsoon should be lesser than what it used to be, let’s say, ten years ago,” said K J Ramesh, former Director General of Meteorology at IMD.
With the rainfall this season expected to be the lowest in at least a decade, India’s resilience will be tested. Thanks to the abundant rainfall in the last two years, the major reservoirs are running at relatively good storage levels. The rapid increase in renewables capacity is reducing the reliance on hydropower, and preserving storage levels in reservoirs. And there are indications that timely forecasts of a potentially bad monsoon prompted farmers to sow kharif crops amid pre-monsoon showers.
“Under climate change scenarios, it is going to get even more unpredictable. Even when we get quantitatively good rainfall, regional and local variations are huge. Developing greater resilience is the only way forward,” said M Rajeevan, former Secretary of the Ministry of Earth Sciences.
Mumbai received its first good rainfall of the season on Tuesday. (Amit Chakravarty)
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