Landslide dams: Hazards and mitigation

Abstract

Landslide dams commonly occur in steep-walled, narrow valleys in high rugged mountains. They are caused by different types of landslides; high precipitation and earthquakes are their most important causes of initiation. Most of the dams fail within a few hours or days, but some may last for several thousand years, depending on many factors. Landslide dams create the potential for flooding both upstream (failure of the lake) and downstream (failure of the dam). Casualties from some of the floods derived from their failure have reached into the many thousands. Construction of protected spillways, stabilization of lake levels by drainage through gravity and siphon pipes, pumping systems, and tunnel outlets are among the most commonly used methods of improving the stability of landslide dams.