Debris flows are geophysical phenomena intermediate in character between rock avalanches and flash floods. They commonly originate as water-laden landslides on steep slopes and transform into liquefied masses of fragmented rock, muddy water, and entrained organic matter that disgorge from canyons onto valley floors. Typically including 50%–70% solid grains by volume, attaining speeds >10 m/s, and ranging in size up to ∼109 m3, debris flows can denude mountainsides, inundate floodplains, and devastate people and property (Figure 43.1). Notable recent debris-flow disasters resulted in more than 20,000 fatalities in Armero, Colombia, in 1985 and in Vargas state, Venezuela, in 1999.
Additional publication details
|Publication type||Book chapter|
|Publication Subtype||Book Chapter|
|Title||Mechanics of debris flows and rock avalanches: Chapter 43|
|Contributing office(s)||Volcano Science Center|
|Larger Work Type||Book|
|Larger Work Title||Handbook of environmental fluid dynamics, Volume One|