Gradient mapping of pattern ground characteristics from a photomosaic of the IBP tundra biome site near Barrow, Alaska

Abstract

An air photographic mosaic covering an area of 44.5×10 5 m 2 was subdivided into 741 rectangular cells (60×100 m). Pattern frequency, center relief, shape, and wedge image clarity were tabulated using three states for each character on a nominal scale. These state variables were converted to an interval scale by the application of a spatial smoothing filter. The new values were subjected to a principal components analysis which indicated that a parsimonious classification of pattern spatial variation could be constructed by equally weighting the first three nominal variables (frequency, relief, shape). The maps derived from this scheme indicate the areas on the tundra surface where polygon evolution may be occurring at the present time.