It’s official: there is no imminent danger from the lake formed by a landslide that has blocked Tibet’s Pareechu river, as The Indian Express first reported.
“(An) immediate, sudden complete breach is unlikely,’’ says a report prepared by the official team, after a visit to Himachal, and submitted today to the Crisis Management Group set up by the Centre. There’s a catch, though: the team has admitted that it’s not clear how high is the debris wall.
The Chinese have come up with figures ranging from 35 to 80 metres—the latest being 70—and experts have admitted that it is difficult to calculate the risk accurately with such wide variations. The team has stressed that China should be asked to reconsider the request to send an Indian team to the site.
According to the report, it’s important to know the dimensions of the gorge too to get an idea of the pressure on the wall.
But the good news is that in another month or so, with the onset of winter, the lake will start freezing. Once it’s frozen, a breach is unlikely, experts agree.
Besides, the overflow has marginally increased—from 40 cumecs to 100 cumecs—and the size of the lake has remained stable at 193 hectares for the last three days.
While the inflow has reduced, outflow has increased, reducing pressure on the wall, experts felt.
The best way out now, they have said, is to set up more monitoring stations to get enough lead time, if the breach happens.
A guage has already been set up at Samdoh, where Pareechu meets Spiti, and there’s a proposal to set up a station at Lepcha, where the river enters India.
The team will have another look at earlier satellite pictures—before the landslide— to a better idea of the lake’s dimensions.
The expert group, which was formed last week, includes members from the Central Water Commission, Geological Survey of India and National Remote Sensing Agency. It will update the report with more inputs from the National Remote Sensing Agency and the Chinese government.