Authorities in Kerala have lifted the shutters of at least 12 dams to ease the threat of floods. Record-breaking rains this month (October 2021) continue the pattern of inclement wet weather that the state has experienced for the past few years. The summer of 2021 saw the heaviest rainfall in the state this century.
A fresh spell of easterly wave is likely to affect south Peninsular India from 20th October and cause fairly widespread rainfall with isolated heavy falls likely over Kerala from 20th October and likely to continue for subsequent 3-4 days.
— Meteorological Centre Thiruvananthapuram (@imd_trivandrum) October 17, 2021
As per official data, Kerala receives 361.5mm of rain from March 1 to May 31. This summer, it received a record rainfall of 750.9mm. In 2004, the state recorded 741.8mm rainfall. But 2021 broke the record. In 2020, the state received 386.4mm (7 per cent excess) rainfall.
Also read: On the edge: 12 dams opened as Kerala braces for more rain
In the summer of 2019 and 2020, Kerala received 169.6mm and 521.8mm of rainfall, respectively. As per data issued by India Meteorological Department, the 2021 season concluded with 108 per cent excess rainfall – the heaviest in 20 years.
It was the fifth-heaviest rainy season on record. In 1933 Kerala saw 915.2mm rainfall. In 1960 791mm, in 1932 788mm, in 1918 767mm.
This year, all districts, especially ones in the southern parts, received excessive rain. Pathanamthitta recorded the highest summer rain with 1342.6mm, while Palakkad district recorded the lowest summer rain in 2021 with 440.9mm.
Climate change
From the 2018 ‘flood-of-the-century’ to last week’s unseasonal downpour, climate change is to blame for the extreme weather.
Experts say the temperature over the Arabian Sea has risen by 1.2 to 1.4 degrees in the last two decades, increasing the frequency of cyclonic events.
“More than 90 per cent of the heat on Earth is absorbed by oceans. Usually, temperatures in the Indian Ocean and Bay of Bengal are above 28 degrees C and in the Arabian Sea, it is 26-28 degrees. But the Arabian Sea is warming up fast,” said Roxy Mathew, a scientist with Pune’s Indian Institute of Tropical Meteorology.
There was a 52 per cent increase in cyclonic movement over the Arabian Sea between 2001 and 2019 and eight per cent during the same period in the Bay of Bengal. IMD statistics show nine cyclones or major depressions were formed in 2020, out of which four were over the Arabian Sea.