While popular scientific speculation about the devastating floods in Uttarakhand tend to attribute them to a torrential ‘cloudburst’, a senior climatologist with the Indian Institute of Science has contended that, curiously, the rainfall received in Kedarnath on June 16 and 17 “was not unusual” in these parts.
J. Srinivasan, chairman of the Divecha Center for Climate Change, says that his analysis of satellite data (there were no automatic rain gauges in this valley) indicates that the heaviest spell of rainfall, which lasted a few hours, did not exceed 20 mm/hr. Whereas, “a cloud burst is an intense rainfall event with rainfall intensity above 100 mm/hr,” Prof. Srinivasan says in the latest edition of journal Current Science.
The argument that rain alone caused this ‘tsunami’ of debris and mud, has got to be “simplistic at the very least,” he told The Hindu. After all, Kedarnath receives higher rainfall almost every July and August, and in the 100 years of recorded climate history here, there is no known precedent of flash floods. What then did cause the catastrophic floods? “It is still a puzzle,” says Prof. Srinivasan. “In order for this event to occur, you would have needed one million metric cube of water. And this could have only been released by a combination of events.” The combined breaching of the Chaurabari sarovar and another lake (created by a landslide dam) will have to be explained, he added. The professor, who coincidently had a narrow escape from the floods while travelling to Badrinath, says that the India Meteorological Department had, in fact, used computer models to correctly predict heavy rain (over 100 mm/day) in Uttarakhand 48 hours before it occurred, and that a warning on the 16th could have saved lives.
There is an “insufficient interaction between operational agencies and academic/research institutions in tackling problems of immediate relevance to the country.” Prof. Srinivasan cautions, however, that Uttarakhand has seen several intense rainfall episodes in the past decade, most of them taking place during July and August. And while these caused landslips and deaths, they “did not receive as much media attention because they did not occur near any famous pilgrim centre.”