NEW DELHI: A massive flash
that ravaged through the valleys of Rishi Ganga, Dhauliganga and
rivers last month was triggered by a massive rockslide just below Ronti peak and the energy of the fall melted the ice creating the source of flood, said findings of an intergovernmental body, International Centre for Integrated Mountain Development (ICIMOD).
The findings, released on Friday, said the energy of the fall of 22 million cubic metres of rock mixed with ice and snow “remobilised the debris and ice on the valley floor deposited by previous events, pushed the stream water and created an excessive flood wave”.
The ICIMOD researchers found that the rockslide had an approximate width of 550 metres at the upper edge at 5,500 metres above sea level.
Noting that the event was definitely not caused by a ‘glacial lake outburst flood’ as there were no significant glacial lakes in the area, the report said a couple of days prior to the February 7 event, a strong western disturbance resulted in heavy precipitation, which increased the flood magnitude.
The Kathmandu-based ICIMOD has eight member countries, including India, on board which is considered as the most authoritative voice in the Hindu Kush Himalayan region.