Bhubaneswar: An IIT Bhubaneswar study found that cities in north-eastern and central India are most vulnerable to extreme rainfall events.Panaji leads with 4,257 heavy rainfall days and 1,376 very heavy rainfall days, followed by Gangtok, Mumbai, Dispur, and Shillong over 100 years. These cities experience around 30 to 45 heavy rainfall days and 10 to 20 very heavy rainfall days every monsoon. The research conducted by Pragatika Panda and Sandeep Pattnaik from the School of Earth Ocean and Climate Sciences, IIT Bhubaneswar, examined rainfall patterns from 1922 to 2022. It focused on monsoon months (June to September) for all capital cities and their respective 100 km surrounding areas across four homogeneous regions of India. The research paper was published in the peer-reviewed journal “Theoretical and Applied Climatology”.“For the first time, a comprehensive study analysing 100 years of rainfall data has revealed significant patterns in heavy rainfall occurrences across India’s capital cities. This highlights increasing vulnerabilities in urban areas amid climate change scenarios,” said Pattnaik.He said Mumbai and Shillong showed a notable increase in very heavy rainfall intensity over the past two decades (2002-2022). The study revealed that Shillong experiences the highest increase in rainfall events per decade (18 heavy and 20 very heavy rainfall events), followed by Mumbai, Panaji, and Dispur.In contrast, cities in the southern peninsular and north-western regions show less significant variations, with only 10 to 20 heavy rainfall days and 2 to 5 very heavy rainfall days per monsoon season. The maximum intensity typically ranges between 65 and 75 mm/day for heavy rainfall and 125 to 150 mm/day for very heavy rainfall events.The research also highlighted concerning patterns of consecutive two-day extreme rainfall events. Mumbai recorded 1,500 days of consecutive heavy rainfall and 550 days of very heavy rainfall, while Panaji experienced 1,600 and 290 days respectively. Similar patterns were observed in Gangtok, Shillong, and Dispur.Bhubaneswar, specifically, has shown an increasing trend with four heavy rainfall events and one very heavy rainfall event per decade. The city recorded 1,477 heavy rainfall days (14.62 days per monsoon season per year, around 12 per cent) and 302 very heavy rainfall days (3 days per monsoon season per year, around 2.5 per cent) out of total monsoon rainfall days over the century.These findings emphasise the urgent need for targeted adaptation strategies in vulnerable urban areas, particularly in the north-eastern and central regions of India, as cities continue to face increasing challenges from extreme rainfall weather events, said the researchers.
