The devastating flash floods in Nepal have driven home important lessons of undertaking systematic scientific assessments of glaciers in order to understand and mitigate hazards and to develop a land use policy in the Himalayan region, experts said.

Over 460 people from Nepal and Tibet have been killed, and thousands, including Indian tourists, are missing after massive flash floods hit parts of Nepal on Wednesday, wreaking havoc across several towns and villages, washing away critical bridges and crippling a dozen hydropower projects.

Initial speculation after a sudden surge near the Nepal-Tibet border crossing in Rasuwagadhi included a glacial lake outburst flood (GLOF) and an avalanche.

However, researchers from the International Centre for Integrated Mountain Development (ICIMOD), based near Kathmandu, are investigating whether an ice-rock avalanche originating from a high-altitude location may have triggered the floods.

A large volume of ice and rock...