By: Rakesh Lohumi, Sr. Editor-ICN Group
SHIMLA: Highly prone to severe earthquakes, the Himalayan region is becoming increasingly vulnerable to glacier lake outburst floods (GLOFs) caused by moraine-dammed lakes. As per the GLOF-risk assessment carried out by Nepal-based International Centre for Integrated Mountain Development (ICIMOD) that there are over 8,000 glacial lakes in the Hindu Kush-Himalayan region, out of which about 200 are potentially dangerous.
The bursting of such a lake increases the discharge in its stream, causing flash floods in the downstream areas with huge loss of life and property. Large chunks of populations in the hills, mainly in the states of Jammu and Kashmir, Uttrakhand and Himachal Pradesh and Nepal, are at grave risk as the number of such lakes is increasing at an alarming rate due to global warming.
A pilot study undertaken by the Himachal Centre for Climate Change has revealed that the number of moraine-dammed lakes has shot up from596 2013 to 705 in 2015 in Himachal alone. Further, there are at least 30 such lakes in Tibet as per the ICIMOD.The increase of 109 glacial lakes within a short period of two years is indeed worrisome for the state which has already experienced one such event in the bursting of Parechu Lake, which was formed in Tibet in the tributary of Spiti River. It created panic among the people living downstream during the summer of 2004 as there was no warning system and no definite information was available on the status of lake.
The people heaved a sigh of relief only after it burst in June 2005 without causing any loss of life as the administration had already moved people living along the banks of Sutlej right from Sumdoh in Kinnaur, bordering China, to Slapper in Mandi.The study on Himachal indicates that glacial melting has accelerated across the mountain ranges as number of such lakes had increased in all the major river basins.
In Chenab basin the number has risen from 116 in 2013 to 192 in 2015 , whereas in 2001 there were only 55 lakes. Similarly, in the Ravi basin it increased from 22 to 34 and in Beas basin from 67 to 89. The Sutlej basin, where the number during the study period remained static at 391, had witnessed a marked increase in glacial lakes from mere 38 in 1994 to 391 in 2013.It has ten large lakes spread over more than 10 hectare and 45 lakes between 5 to 10 hectare.
The study has underlined the need for putting up an effective mechanism in place for regular monitoring of the glacial lakes which pose a threat to the habitations in the downstream areas. More so , as population in the hills is increasing rapidly due to unrestrained and haphazard urbanisation. Buildings are coming up along the banks of rivers in the danger zone.