CLASSIFICATION AND BOUNDARY VAGUENESS IN MAPPING PRESETTLEMENT FORESTTYPES

Presettlement forest types were mapped as fuzzy sets from point data r epresenting trees contained in General Land Office survey notes (circa 1850) for Chippewa County, Michigan. The resulting representation agr eed with a polygon map of the same forest types at 66 % of the locatio ns (represented as grid cells) in the county. Boundary vagueness was d efined in relation to the slope of a linear function fitted to the neg ative relation between entropy of forest types and distance to polygon boundaries. The similarity between forest type compositions (i.e. cla ssification ambiguity) was shown to account for 55% of the variation i n boundary vagueness.