Although surfaces are central to geographical analysis and geographical information systems, data is often not precise because of the uncertainty inherent in GIS and remote sensing data acquisition systems. This book presents methods to address such uncertainties within the framework of GIS. It defines the mathematics associated with each method, develops related algorithms, and illustrates various applications. The author has included the pseudo code in the book while the associated code itself may be run by utilizing the CD that comes with the book. The applications that are presented illustrate the concepts and indicate the relevance, richness, breadth, and depth of analyses that are possible with fuzzy surfaces.