ABSTRACT
Interactions between large mass movements and alpine river channels significantly extend the range of geomorphic forcing mechanisms and hazards in mountainous environments. They encompass a range of phenomena such as catastrophic outburst floods from temporary landslide- or debris-dammed lakes. They also promote channel instability and metamorphosis due to excessive sediment loading, transformation of gravitational to long run-out flow movements on groundwater-saturated valley floors, and landslide-induced formation of steps, pools and riffles in the stream long profile. It is proposed that the geomorphic efficiency of landslide impact on alpine valley trains is not a sole function of landslide magnitude (e.g. volume), but also a result of topographic position, mode of failure, and the nature of the channel-hillslope coupling interface.
