Harindra Joseph Fernando Richard M. Iverson 2012 <p><span>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 &gt;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&nbsp;1999.</span></p> application/pdf 10.1201/b14241-47 en CRC Press Mechanics of debris flows and rock avalanches: Chapter 43 chapter