ABSTRACT
There are two principal types of logic which are used and applied in spatial data processing: Boolean and fuzzy logic. This chapter explores three areas where either fuzzy or probable models of spatial regions are appropriate, depending on the conceptual understanding of the issues and the phenomena. It first examines the viewshed and then general spatial regions and land cover mapping from satellite imagery. The viewshed function is common in GIS that are used for analysing surface elevation. There are two forms of uncertainty or poorly defined viewshed regions: probable viewshed recognizes the uncertainty over whether a location is visible; and fuzzy viewshed defines the degree to which any potentially visible target can be distinguished. One of the most widespread and important products of satellite imagery is the land cover map, in which each pixel in the area of the image is assigned to a particular land cover type.
