Key facts
- A flash flood triggered by a glacier collapse in Nepal has caused widespread devastation.
- Satellite imagery reveals destroyed villages, bridges, and hydroelectric power stations along the Trishuli River.
- Over 550 people have been killed, and hundreds are missing.
- A crucial Nepal-Tibet border crossing has been almost entirely washed away.
- A barrier lake has formed at the landslide site, raising concerns about further flooding.
Satellite images have revealed the extensive devastation caused by a flash flood in Nepal, triggered by a glacier collapse on Wednesday. The disaster has claimed over 550 lives, with hundreds still missing, and has obliterated villages, bridges, and hydroelectric power stations along the Trishuli River.
Before-and-after satellite views show sections of the valley inundated by a torrent of floodwater and debris. BBC Verify's analysis highlighted a key Nepal-Tibet border crossing that was engulfed by the flood, with imagery from Vantor showing the site has been almost entirely washed away. CCTV footage captured the moment the deluge swept over buildings as people attempted to escape.
Damage, including mud, extends more than 2.5km upstream and reaches 100m above the initial impact area. The village of Timure has largely disappeared, with most houses on its steep slopes gone or covered in mud. Further downstream, the village of Syapru Besi is covered by mud, rock, and debris, with structures and bridges submerged. The town of Trishuli, 45km from the border, has seen an entire neighborhood washed away, with verified videos showing a bridge collapsing.
Imagery from Planet Labs shows the origin of the disaster: a collapsed glacier that carved a massive path of rock and debris. Trees and vegetation were stripped over 300m above the riverbed. The destructive path continues southwards, where a barrier lake has formed at the base of the landslide. Chinese authorities have warned this lake poses a significant risk of further flooding and has hindered rescue efforts.
Dr. Argha Banerjee, a glaciologist, noted that while the lake's surface area had not significantly increased between Wednesday and Thursday, water was visibly draining. He stated the volume was not alarmingly large and appeared stable, though its overall stability and likelihood of sudden drainage remain undetermined from the images alone. The extent of damage on the Tibetan side of the border is unclear due to restricted access. Vantor released the imagery to aid authorities in rescue and recovery efforts.