ACCURACY ASSESSMENT OF A LAND-COVER MAP OF THE KUPARUK RIVER BASIN, ALASKA - CONSIDERATIONS FOR REMOTE REGIONS

An accuracy assessment of a Landsat MSS-derived land-cover map of the Kuparuk River basin, Alaska was performed. We used a stratified system atic transect-based sampling design with a homogeneous 3- by 3-pixel b lock sampling unit. The ramifications of the sampling strategy are dis cussed. Sample sites were located using a helicopter and a Y-Code GPS receiver. Estimates of overall classification accuracy (P), Tau (T-e) producer's accuracy, and user's accuracy were calculated from an error matrix. Assessment methods based on fuzzy sets theory were used to su pplement the error matrix. The accuracy estimates indicate a classific ation with high accuracy. However, they are likely to have a fair degr ee of optimistic bias and can only be applied reliably to homogeneous 3 by 3 blocks of pixels. The combined use of an error matrix and fuzzy sets allowed for a more precise analysis of errors. Based on this ana lysis, changes were made to the final map. Several methodological adva ntages contributed to the high classification accuracy.