Testing of two date change detection using a modified enhancement classification method

Abstract

The Enhancement Classification Method (ECM) has demonstrated considerable success in mapping Canada's forests and here is extended to facilitate clustering and labeling within a two-date classification. Central to the method, is an interactive cluster formulation based upon color rendition. A multi-date image enhancement is employed to facilitate an RGB rendition of change and cluster sieving is undertaken through spatial generalization. The remaining core clusters are reapplied via a minimum spectral distance. The method was tested on a 1984 - 1988 co-registered and normalized Landsat scene pair over a forest harvesting area near Petawawa, Ontario. Clusters (123) were derived and labeled. Results identified forest depletion (clear cuts and partial cuts) fairly well and captured stable forest composition moderately well and pre-change cover type moderately well. Burns, hail, forest blowdown and deforestation events were not recognized individually in single clusters, rather they were generally lumped into clearing classes. Consequently depletion requires a composite of classes to establish an intensity and localized cluster labeling.