ISRO's Hyderabad Centre Reveals Glacier Collapse Triggered Nepal Flash Floods

A massive glacier collapse in the upstream Himalayan region triggered flash floods that struck Nepal’s Rasuwa district, according to satellite imagery and preliminary assessments released by the National Remote Sensing Centre (NRSC) of the Indian Space Research Organisation (ISRO) in Hyderabad.

The satellite assessment revealed a major disturbance in the high-altitude glacier and mountain terrain upstream of the affected area. Post-disaster images were captured by ISRO’s Resourcesat-2A AWiFS sensor on August 26, 2026, at approximately 10:30 am IST and compared with pre-event data to evaluate terrain and river system alterations.

According to the NRSC's preliminary analysis, an estimated two-thirds of the glacier’s body detached and collapsed. This triggered an ice-rock avalanche and landslide, which sent a large mass of ice and debris downslope. The resulting blockage of the river and rapid melting led to a sudden release of impounded water and a heavy debris surge along the Trishuli river system.

The satellite observations documented a swollen Bhote Koshi river, with inundation spreading beyond the normal channel into adjacent valley sections. A post-disaster Landsat-9 image from August 26 identified the specific zone of glacier breakage in the upstream terrain. In contrast, pre-disaster Sentinel-2 imagery from August 24 recorded the intact glacier prior to the collapse.

The affected corridor is located in Rasuwa district near the Nepal-Tibet border, encompassing areas such as Rasuwagadhi, Timure, and the broader Trishuli river network. The satellite views highlighted a broad disturbed tract moving from the glacier zone down toward the drainage system.

NRSC noted that its findings remain preliminary and that a comprehensive evaluation will follow. The satellite maps did not quantify the total flooded area, debris volume, river discharge, or infrastructural damage, partly because cloud cover obscured portions of the impacted zone.