Are landscapes as crisp as we may think?

Geographic information is traditionally represented by a one-entity one -class method, assuming that each geographical entity in the map can be unambiguously assigned to a single thematic class. Also, thematic map classes are assumed to be exhaustive and mutually exclusive. By contrast, fuzzy classifications overcome the traditional limitations on the mutually exclusive nature of map classes assigning varying levels of class membership for individual map entities. The aim of this paper is to show that the substitution of fuzzy set theory for classical set theory is an essential improvement for representing geographic information using hierarchical classification schemes. (C) 2007 Elsevier B.V. All rights reserved.