Sensitivity of the thematic mapper enhanced wetness difference index to detect mountain pine beetle red-attack damage

摘要: Red-attack damage caused by mountain pine beetle (Dentroctonus ponderosa Hopkins) infestation in stands of lodgepole (Pinus contorta) the Prince George Forest Region British Columbia was examined using multitemporal Landsat-7 ETM+ imagery acquired 1999, 2000, and 2001. The image data were geometrically atmospherically corrected, processed Tasseled Cap Transformation (TCT) to obtain wetness indices. final steps included pixel subtraction, enhancement, thresholding index differences. resulting enhanced difference (EWDI) used interpret spectral patterns with confirmed (through aerial survey) red-attack 2001, these EWDI compared reflectance normal-colour composites. We stratified survey dataset into two levels discriminate classes 10–29 trees 30–50 trees, a sample healthy forest collected from inventory data. Classification accuracy based on ranged 67% 78% correct.