(Photo by L. Polvi)
Sediment entrainment by overland flow has been shown to be the dominant mechanism for debris flow generation in poorly vegetated arid and semi-arid landscapes and in steep terrain burned by wildfire (Wells 1987, Cannon et al. 2008).
First- and second-order channels have more frequent and longitudinally extensive impacts from debris flows.
If these debris flows accumulate enough mass, they may significantly contribute sediment and woody debris to the mainstem channel.
(Information compiled by Liz Gilliam)
Flooding may occur in ephemeral channels in the rain dominated areas below 2,300 m and will occur as short-lived flood waves.
Debris flows will most likely occur in these areas as compared to flood waves. Jarrett and Costa (1981) have shown that many large floods that were attributed to intense rainfall may be debris flows and not water floods.
(Photo by E. Wohl)
Click a link below to learn about disturbance regimes in each process domain:
| Colluvial Hollows | Ephemeral Channels | Glaciated Confined | Glaciated Partially Confined | Glaciated Unconfined | Unglaciated Confined | Unglaciated Partially Confined | Unglaciated Unconfined |