Formation of Dam from Debris Flow in the Southeast Tibet

Abstract

Glaciers with their deposits abound in the high mountains of the Southeast Tibet. Large-scale debris flow occurs frequently from these deposits and forms dams that block mainstreams. In this paper, seven events of large-scale debris flows occurred in four gullies, from which five blocking dams resulted, are discussed in details, focusing on the major factors impacting the dam formation. Result shows that the first surge group caused by snow and ice avalanches, ice-lake break, and large-scaled landslides, with peak discharge and high speed, and in abundance with boulders, are most likely to form blocking dams.