Abstract
Landsat TM digital data were enhanced through a combination of ratio, spatial filtering, and principal components analysis to discern the composition, orientation, and dimensionality of snow avalanche paths within a portion of Glacier National Park, Montana. A set of control paths were identified that represented variability in elevation, slope angle, slope aspect, vegetation regeneration, length, and width. Attributes related to the characteristics of each path, organized within INFO tables of a Geographic Information System, were searched to identify paths that offered a unique combination of the test variables. Data contained within the GIS served as control attributes for comparison to the TM digital enhancements. The success of each enhancement technique was validated by the development of a Spectral Variability Index for the in-path versus out-path pixels.