Lunetta, R., B. Cosentino, D. Montgomery, E. Beamer and T. Beechie. 1997. GIS-Based Evaluation of Salmon Habitat in the Pacific Northwest. Photogrammetric Engineering and Remote Sensing 63: 1219–1229.

Using GIS, authors categorized streams in western Washington according to their potential as salmon habitat. Channel slope and forest seral stage were used to roughly estimate stream condition.  High quality salmon habitat was defined as being low gradient and existing in later seral stage forests.  Older forests are a source for large wood which creates pool-riffle habitat used by salmon.  Using 30-meter DEM data, low gradient reaches (<4% slope) were accurately identified (96% accuracy). About 23% of reaches had slopes less than 4%.  Of these 8.7% were in late-seral and 20.7% in mid-seral stage forests.  Authors found GIS analyses to be less accurate in predicting channel morphology.  However, overall findings from the GIS-based analyses were similar to those from field based assessment.  For example, both the GIS analysis and field research found that the greatest habitat losses have occurred in the Skagit River floodplain and delta. GIS was determined to be a quick, objective and cost-effective mechanism of identifying priority sites for salmon habitat restoration.