Scientists conduct risk assessment of Arunachal’s Rani Lake amid glacial flood concerns

A team from the Centre for Earth Sciences and Himalayan Studies (CESHS), on April 26, carried out a comprehensive risk assessment of Rani Lake, a Category-B glacial lake.

The lake has been identified by the National Disaster Management Authority (NDMA) for its potential to trigger Glacial Lake Outburst Floods.

Rani lake is situated at Gorichen Peak in Arunachal Pradesh's Tawang district.

The team collaborated with the National Centre for Polar and Ocean Research (NCPOR) in Goa, the Union Ministry of Earth Sciences, and the Indian Institute of Technology Guwahati.

The assessment took place during the third high-altitude expedition to the Khangri Glacier in Gorichen Mountain region from April 19 to 26, CESHS Director (ES) Tana Tage said.

He said four scientists and engineers each from NCPOR and CESHS, and one expert from IIT Guwahati, undertook detailed glacio-hydrological studies aimed at understanding the glacier's health and associated water resources.

Key activities included glacier mass balance measurements at 5032 msl aimed at understanding the glacier's health and response to climate change, Tage said.

The assessment involved a bathymetric survey to determine lake depth and volume, along with terrain observations to evaluate moraine stability, drainage pathways, and downstream hazard potential.

Additionally, the team also performed maintenance of water level sensors and conducted direct measurements of glacier meltwater discharge, enabling accurate assessment of total runoff from the glacier system.

Marking another first-of-its-kind initiative, he said the team carried out a first-ever reconnaissance survey of a cluster of Category-B glacier lakes located at an altitude of 5300 msl.

These lakes, identified by the NDMA, were assessed for their risk potential to inform future hazard mitigation and disaster preparedness strategies.

He said reaching the remote site involved a strenuous high-altitude trek across rugged terrain, snow-covered passes, and rapidly changing weather conditions, indicating the logistical challenges faced by the scientists.

In order to make such expeditions more convenient, the team successfully identified a suitable site at Mirathang for establishing a long-term high-altitude Field Research Station, Tage added.