Precipitation averages about 1500 mm annually. A debris flow routing algorithm was applied to the DEM and used the areas identified as high risk by the shallow landslide model as starting points for debris flows. The algorithm created down slope debris flow routes based on DEM slope gradients. The routing process terminated when slope gradients no longer exceeded 3.5 degrees. Location of potentially unstable GRID cells.
Debris flow locations and impacted streams.
55.70 29.45 Table 1. Mean values of large woody debris, large boulders, and percent gravel. We can infer from these results that there were significantly more large boulders in stream reaches that were influenced by debris flows than in stream reaches that were not. Discussion Support for the contribution of debris flows to quality aquatic habitat conditions was present in the significantly higher number of large boulders found in debris flow impacted stream reaches than in non-impacted stream reaches. Support for the contribution of debris flows to large woody debris and gravel quantities was absent, however, given the insignificant differences detected in the variable distributions.