After a brief respite, rains in Kerala are likely to gain strength from October 20 onwards, the India Meteorological Department (IMD) has warned. The state may get heavy, isolated rainfall for three to four days from October 20. An easterly wave that affects south peninsular India will be responsible for the rains, said IMD. Several districts have been issued a yellow warning –urging authorities to be updated on the situation – from October 20 to October 22, with heavy rains, thunderstorms and squall forecast.
A yellow warning has been issued to the districts of Thiruvnanthapuram, Kollam, Pathanamthitta, Alappuzha, Kottayam, Ernakulam, Idukki, Thrissur, Palakkad, and Malappuram, where isolated heavy rainfall is forecast on October 20. The yellow warning has also been issued for Thiruvananthapuram, Kollam, Pathanamthitta, Idukki, Palakkad and Malappuram on October 21.
According to the state government, 1,143 families have been shifted to relief camps across the state following heavy rains and landslides on October 16. The death toll in the state due to rains and landslides is 28. The search for missing people continues in Kokkayar of Idukki and Koottikkal of Kottayam district, where landslides struck.
Kerala Chief Minister Pinarayi Vijayan has warned that water levels in the rivers of Pathanamthitta, Kottayam and Thiruvananthapuram will rise again. He asked residents living close to rivers in these areas to be careful.
Meanwhile Kerala has postponed the college reopening in the state. The reopening was scheduled for Monday, October 18. A government order dated October 17 said that in view of the rains in Kerala, the colleges will reopen only on October 20.
The Sabarimala pilgrimage was also stopped until October 19 due to the rains and flash floods. As the water level in Pamba river has increased, there were concerns over the Sabarimala pilgrimage.
The brief, intense rain spells in a couple of regions in Kerala indicated mini cloudbursts, a factor that also led to casualties, damage and loss of properties, a scientist at the Cochin University of Science and Technology (CUSAT) said on Sunday. Citing more than 5 cm rain received in two hours in worst affected areas of Idukki and Kottayam districts, S Abhilash of the Department of Atmospheric Sciences, CUSAT said it was a "mesoscale mini-cloudburst type of event".
Mini cloud bursts are marked by intense short spells which may not exceed 10cm in one hour-a classical definition by India Meteorological Department, he noted. Abhilash told PTI that the high range areas of Western Ghats region in Kerala is very susceptible to landslides. The starting point of the catastrophe in Idukki and Kottayam are the cloud bursts in the high ranges and the sudden, heavy rainfall continuing, leading to landslides and flash floods, which resulted in loss of lives and destruction of properties, he said.
The damage potential of less intense rain spells (about 5 cm in 2 hours) may cause flash floods and landslides along the slopes of Western Ghats mountains and Himalayan regions, Abhilash has said in an article published in the latest issue of a state government publication. Heavy rainfall for a short duration especially from mesoscale mini cloudburst events also brings runoff water beyond the carrying capacity of the streams and flushes off rainwater faster. Rivers and midland regions of the west coast often may experience the frequent occurrence of flash floods, he said.
The combined effects of cloudburst, landslides and flash floods may get aggravated by degradation of land due to human activities such as the conversion of forests to plantation and crop fields, Abhilash opined.
Changes in Kerala's climate received more attention during recent times as evident from back-to-back drought conditions during 2015 and 2016. In 2017 Kerala, was hit by the cyclonic storm Ockhi and catastrophic flood and landslide episodes followed during 2018, 2019 and 2020, he pointed out.