Arunachal disaster management team visits Jerjang Lake to study GLOF potential

A five-member team from Tawang's District Disaster Management Authority (DDMA) visited Jerjang Lake in Arunachal Pradesh's Zemithang Sub-Division on September 29 to conduct preliminary studies on the lake and its potential for Glacial Lake Outburst Flood (GLOF).

The team embarked on a three-hour trek through challenging terrains, including steep uphill climbs and numerous rivulet crossings, from the nearest motorable point at Daula Camp. They reached Jerjang Lake at 9:30 am and conducted various assessments, along with the collection of rock and soil samples.

The team spent around two hours studying the lake's characteristics, including its depth, volume, the width of the discharge channel, flow velocity, slope from the lake outlet, embankment width, and water turbidity.

It was observed that in the event of a GLOF from Jerjang Lake, areas such as Brokenthang, Zemithang Gorsam, Baptengkhang, and Namtsering and Army and SSB, ITBP camps near Namka (Chu), could be severely impacted due to the high velocity of the water flow. The time it would take for floodwaters and debris to reach these areas is estimated to be very short due to high velocity of the flow of the discharge water.

However, as of the current assessment, the risk of a GLOF event from Jerjang Lake appears to be low. The embankment is natural, with a thickness ranging from 30 to 40 meters, and the distance from the lake’s outlet to the nearest gradient is approximately 100 meters.

Zemithang Circle Officer D. Mara, DDM Deputy Director  D. Khandu, SDE CWC Jitendra Kadwa, AE WRD  N. Likha, and trek leader cum photography expert Jambey Dondu, completed the expedition and returned to Dhaula camp the same day.

The team expressed their gratitude to the Indian Army for its support and cooperation, which contributed to the success of the expedition.