Himalayan Flood Disaster Analysis

High in the Himalayas, rivers begin as small streams

beneath glaciers and snow fields.

The disaster began upstream of Nepal in the high altitude river

system connected to the Bhote Koshi.

Scientists believe a major ice and rock collapse occurred high above the

river.

An enormous mass of ice, rock, and debris crashed into the

valley below.

The collapse appears to have obstructed the river, creating a rapidly changing

and unstable water system.

When that unstable blockage failed, a sudden surge of water and

debris raced downstream.

The surge followed the natural river valleys toward the Nepal border.

The flood reached the Rasuwagadhi border area with extraordinary

force.

Communities and infrastructure along the Rasuwa River corridor were

overwhelmed.

This was not simply rising river water.

The surge carried enormous amounts of sediment, rocks, and debris through a

steep confined valley.

The speed and volume of the surge left communities with very

little time to respond.

The flood then propagated downstream through the Bhote Koshi and Trishuli

systems, prompting high alerts in Nuwakot.

Satellite imagery and expert analysis point toward a major

glacier

related ice and rock collapse as the likely trigger.

Scientists are still investigating the exact sequence of events

and what triggered the collapse.

The disaster is also a reminder that hazards beginning high in the

mountains can rapidly affect communities far downstream.

In the Himalayas, understanding what happens above the river

can be

the key to protecting the people who live below it.