Unusual October downpour wreaks havoc in Bengaluru, Hyderabad; experts blame climate change

Several cities in south India bore the brunt of unusually heavy rainfall in the last week even as the monsoon prepares to leave the country. Among other cities, life in Bengaluru, Hyderabad and Mysuru came to a standstill after the sudden high-intensity downpours.

On 5 October, Bengaluru witnessed 65 mm rainfall, which was the highest rainfall in a day in the city since 2007. Bengaluru had been at the receiving end of nature's fury earlier this year as well: in September, four people were killed after a thunderstorm lashed the city.

On the same day, six people were killed and four injured when lightning struck a temple in a Mysuru village, the police said.

Speaking to Firstpost, Sundar M Metri, director of Meteorological Centre, Bengaluru, said that although the overall monsoon rainfall in Karnataka this year is "within the range we call normal", rainfall in October — which is the first of the three months of the 'post-monsoon period' — has been excessive.

"In the three months from October to December 2017, Bengaluru was expected to receive 248 mm of rainfall. The expected rainfall for the month of October is 170 mm. But from 1 to 6 October alone, we have recorded a total precipitation of 140 mm already," Metri said.

This means that by Friday, Bengaluru had already received over half the rainfall expected in the city between October and December. Further, it has received over 80 percent of the rainfall that is normally expected in October.

"The rains from June to July were quite deficient in Karnataka, but the downpour from 15 August compensated for it. Now this may exceed the average monsoon rainfall if the recent trends continue to last," he said.

Representational image. AFP

Representational image. AFP

In Hyderabad, three people were killed after rains pounded the city on 3 October. Of these, two people died in a wall collapse, while one person died of electrocution, News18 reported.  As some parts of Hyderabad received rainfall of  7 cm to 12 cm, officials have termed it as a cloudburst, according to the report.

It is not as much about the unpredictability of these rainfall patterns, as it is about their shifting patterns,  Y Karunakar Reddy, head scientist at India Meteorological Department (IMD) Hyderabad, told Firstpost.

"We had predicted these spells of rain fairly accurately, but weather patterns are now becoming more and more difficult to analyse and hence predict. This year, we've seen several spells of 'short duration high intensity' rainfall, unlike we have seen in previous years.

"These spells are extremely localised and are very heavy, resulting in wet areas getting more rain and dry ones remaining dry," Reddy said, "This trend, which is clearly becoming more predominant year after year, are drastically changing rainfall distribution in the country."

Uneven rains this year have already affected the production of summer crops in the country. As Livemint reported, such rains could lead to lower foodgrain output in spite of bigger planting areas, forcing India to raise imports of edible oils, sugar and pulses, and possibly limiting exports of cotton, rice and feed ingredients, according to traders.

While Metri blames unusual depressions and cyclone circulation on both the Arabian Sea and the Bay of Bengal of late, Reddy insists the cause may be far bigger.

"This is a direct effect of global climate change. Weather patterns are changing much faster than they have been known to change in the past, and global warming and climate change are to blame," Reddy said.

This was echoed by Manju Mohan, head of the Centre for Atmospheric Sciences in IIT Delhi. Although such changing weather patterns have been noticed for the past five years or so, climate change is ultimately to blame for these erratic flooding of cities, she said.

"Another reason of such events is rapid urbanisation. The water soaking capacity of our cities is continuously coming down because of the expansion of the city's infrastructure, which puts the city at a much bigger risk of flooding. It takes much less rainfall to flood a city now than it used to.

"With emissions of greenhouse gases and aerosols only rising in our cities, such unpredictability of violent weather is only likely to continue," Mohan said. However, she added that sometimes such change in the monsoon's behaviour is random, and does not necessarily have to do with anything particular.

Sunil Kamble, director-in-charge, IMD Mumbai, said that Maharashtra continues to receive ordinary rainfall in October. "Monsoon is receding currently, and we expect some irregularities. But overall rainfall during this year's monsoon has been sufficient, except in a couple of districts like Vidarbha," he said.

All experts agree that given the movement of cyclones of the Bay of Bengal, current weather patterns are likely to continue for a while.

Updated Date: Oct 10, 2017 14:51 PM

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