Fluvial disasters in the Himalaya – new insights and potential for early warning

Séminaire de Kristen Cook, senior Scientist, GFZ Potsdam, Germany & IRD (ISTerre)

Natural disasters such as landslides, glacial lake outburst floods (GLOFs), and other catastrophic flash flood events are a major hazard in the Himalayas, and are a growing threat in a warming climate. Such events also have significant geomorphic impacts and may play an important role in Himalayan landscape evolution. While much work is focused on the initiation of extreme fluvial events, understanding their dynamics and downstream impacts is also important for evaluating both hazards and landscape dynamics. I will present observations from three recent fluvial disasters – a glacial lake outburst flood (Bhote Koshi, Nepal, July 2016), a rock/ice slide triggered flow (Chamoli, India, Feb. 2021), and a complex hazard chain (Melamchi, Nepal, June 2021). Each of these events had a different type of source and trigger, illustrating the difficulty of anticipating destructive floods in both space and time and highlighting the need for real-time detection and early warning of such events.