The researchers at IIT-GN’s Machine Intelligence and Resilience Laboratory (MIR Lab), as per a report in PTI, said that the recurrence of such "unusual weather events" along India’s western coast signals an urgent need to reassess urban planning and infrastructure resilience. The study highlights the critical importance of incorporating hydrological considerations into urban development strategies, particularly as rapid urbanization continues to strain drainage systems and alter local hydrology.
Vadodara, one of the cities severely affected by the flooding, faced significant challenges despite the rainfall not being unprecedented. The study noted that extensive urban development in flood-prone areas, altered land elevations, and compromised drainage systems due to clogged channels contributed to the severity of the flooding. This scenario exemplifies the complexities of concurrent extreme events, where multiple regions experience severe weather simultaneously, stretching emergency response resources thin across affected areas.
The IIT-GN analysis also detailed that Devbhumi Dwarka and Morbi in Gujarat's Saurashtra region experienced rainfall last week that surpassed their 50-year return period, with Dwarka exceeding even the 100-year mark. Additionally, 12 districts recorded one-day rainfall totals that exceeded the 10-year return period, and over two days, 17 districts surpassed this threshold, including Jamnagar, Morbi, and Devbhumi Dwarka. Furthermore, 15 districts saw three-day rainfall totals exceeding their 10-year return period, with several surpassing the 50-year mark.
Udit Bhatia, an Assistant Professor in Civil Engineering and Computer Science and Engineering at IIT Gandhinagar and Principal Investigator at the MIR Lab, pointed out that the granularity of the data may not fully capture the nuances of urban flooding, which is often triggered by short bursts of high-intensity rainfall that overwhelm city drainage systems. He explained that when rainfall persists over longer periods, initial downpours saturate the soil, making subsequent rain more likely to contribute directly to surface runoff, thereby intensifying flooding.
"When rainfall persists for longer durations, the soil becomes saturated during the initial spells, and subsequent rainfall is more likely to contribute directly to surface runoff. This runoff exacerbates flooding, especially when drainage systems are either incapacitated or unhealthy," he said.
The study concludes that to effectively manage such extreme weather events, there is a pressing need for robust and scalable emergency response strategies that can address the complexities posed by concurrent disasters, where multiple areas are affected simultaneously.