2014-04-28T16:38:30Z (GMT) by
These files represent maps of mountain pine beetle infestation in Arapaho and Roosevelt National Forests, Colorado, for the years 2003, 2005, 2006, 2009, and 2010. They are identical in their format and methods of preparation, with the exception that they represent different time periods. They were developed from Landsat5 (2005, 2006, 2009, 2010) or a combination of Landsat5 and Landsat7 (pre-scan line corrector failure) imagery (2003) (path 32 row 34). All images were atmospherically corrected and converted to reflectance. Cloud cover was manually removed, with areas obscured by cloud cover in one year removed from all images. The study area was masked to include only forested areas in Arapaho and Roosevelt National Forests. The images were classified using a supervised maximum-likelihood algorithm in ENVI v.4.8 with training classes selected based on initial NDVI and change in NDMI between images. The training classes were hand selected so that Red Attack was represented by pixels having high initial NDVI and declining NDMI between image pairs. The classification was validated by comparison with high-resolution orthoimagery. In each file, 2 represents the binary class "Red Attack," and 1 represents "Non-Red Attack." Files use the UTM Zone 13 N projection based on the WGS 1984 geographic coordinate system.