Nepal Glacier Collapse Explained

What Caused the Nepal Flood? On 26 August 2026, a catastrophic high-mountain disaster unfolded in Nepal’s Langtang region. What began as a major slope failure involving rock and glacier ice rapidly transformed into a rock–ice avalanche, then a debris flow, and finally a destructive flood that travelled through the Lhende Khola, Bhote Koshi, Trishuli and downstream river systems. In this KnowWhy explainer, we reconstruct what may have happened using geography, geomorphology, glaciology, cryosphere science, hydrology, natural hazards geography, satellite imagery and hazard mapping. This event is best understood not as a single landslide, avalanche or flood, but as a cascading high-mountain disaster.