Public warning and evacuation experiences during recent GLOF events (2019 and 2023) and recommendations for future preparedness: Insights from Lunana, Bhutan
This peer-reviewed study offers the first comprehensive documentation of how a remote Himalayan community experienced warning dissemination and evacuation during recent glacial lake outburst floods (GLOFs). Focusing on Lunana in Bhutan — one of the world’s most at-risk basins, surrounded by dangerous glacial lakes and a nine-day walk from the nearest road — the authors use surveys, key informant interviews, and focus groups to examine the 2019 and 2023 Thorthormi GLOF events. Rather than reconstructing the physical mechanics of GLOFs (the focus of most prior research), the study centers on people’s lived experiences: how they first detected the threat, how warnings spread, what protective actions they took, and how prepared they feel for future events.
The findings show that despite a siren-based early warning system in place, informal channels dominated. Environmental cues such as prolonged roaring river sounds and ground vibrations were the most common first warning, followed closely by mobile phone calls from friends and family; the official sirens were not activated during either event (once because the flood stayed below threshold, once because sensors were destroyed by the flood wave). Residents showed high threat perception — shaped by the deadly 1994 Lugge Tsho GLOF and decades of government advocacy — yet remained underprepared in practice, with no mock drills, no prepared “go-bags,” chaotic evacuations, and evacuation sites lacking shelter against extreme overnight cold. Cultural and spiritual attachments to land did not deter immediate evacuation but pose real barriers to permanent relocation.
The authors offer practical, transferable recommendations for strengthening GLOF early warning in mountain communities: make the system more community-based by integrating local people across all EWS components; formally incorporate resilient mobile-phone-based communication (with redundancy via radios, megaphones, and satellite phones); pair indigenous environmental knowledge with technology such as river cameras and citizen science; run regular mock drills leveraging schools and teachers; distribute “grab-and-go” emergency kit checklists; and build permanent, stocked shelters at evacuation sites. Published open access in the International Journal of Disaster Risk Reduction, the study is a valuable resource for practitioners working on community-based early warning, anticipatory action, and disaster preparedness in high-mountain and other remote, hard-to-reach settings.