Kishtwar, Sep 4: A glacial lake in the remote Warwan basin of Kishtwar district has expanded by about 308 per cent between 1999 and 2024, with a new scientific study warning that an avalanche-triggered glacial lake outburst flood could generate a cascading sequence of flooding and debris flows downstream.
The study, currently available as a 2026 preprint, examined mass movements, glacier changes and glacial lakes in the Warwan sub-basin.
Researchers found that Lake-B expanded from approximately 0.075 square kilometres in 1999 to 0.306 square kilometres in 2024.
The study also identified previous avalanche and GLOF events in the basin. An avalanche in September 2020 struck a proglacial lake and triggered a GLOF, resulting in the complete drainage of stored water and sediment and the formation of a downstream debris flow.
For Lake-B, modelling of a worst-case large-magnitude scenario involving a rock-ice avalanche estimated a peak liquid discharge of about 2,214 cubic metres per second immediately downstream of the lake.
The modelling indicated that up to 97.5 per cent of the lake’s water could potentially be drained in that scenario.
The researchers identified settlements including Youdu and Qaderna, along with roads, bridges and residential structures, within potential inundation zones.
They also warned that the availability of loose sediment from previous mass movements could increase the possibility of debris-flow cascades, potentially affecting downstream infrastructure and hydropower facilities.
The researchers stressed the need for preparedness, mitigation planning and early-warning systems closer to the source of a potential GLOF.
The findings represent a modelled risk assessment and do not indicate that an outburst flood is imminent. [KNT]
