2026 Nepal rock-ice avalanche, debris flow and flash flood: preliminary assessment

09.09.2026

This research group, led by Associate Professor Ching-Ying Tsou of the Department of Agricultural and Environmental Engineering, Faculty of Agriculture and Life Science, Hirosaki University conducted a rapid assessment of the large-scale rock–ice avalanche and the subsequent debris flow and flash flood disaster that occurred in Nepal in 2026 using satellite imagery.

This preliminary report presents the results of an analysis of the disaster, including changes in the landscape and damage along the affected river corridor, from the source area to the downstream reaches. The findings currently available have been compiled and are presented here as preliminary information to support future detailed investigations and disaster response activities.

The GIS data produced through this assessment will also be made available to support future disaster response, rescue, recovery, and reconstruction activities. Those interested in using the data are kindly requested to contact the first author.

Finally, we extend our heartfelt sympathies to everyone affected by this disaster and express our deepest condolences to those who lost their lives and their families

2026 Nepal rock-ice avalanche, debris flow and flash flood: preliminary assessment(English)（1.9MB）
Note: We have revised Fig. 3 of the original report posted on September 9 because the information regarding the photo location was incorrect.

Citation:
Tsou, C.Y., Higaki, D., Koiwa, N., Yagi, H., Chigira, M., Takahashi, M., Amatya, S.C., Dhakal, S. (2026): 2026 Nepal rock-ice avalanche, debris flow and flash flood: preliminary assessment,
https://www.hirosaki-u.ac.jp/topics/117029/

■Contact information
Ching-Ying Tsou, Associate Professor
Department of Agricultural and Environmental Engineering
Faculty of Agriculture and Life Science, Hirosaki University
E-mail：tsou.chingyinghirosaki-u.ac.jp