Fuzzy Digital Elevation Model

摘要

Digital Elevation Model (DEM) is often used when referring to the topographic digital representation. Nowadays, DEM is one of the most powerful tools in many applications, such as geodesy, cartography and terrain analysis. DEM also plays an important role in decision making and decision analysis. DEM provides users many advantages, for instance, instead of using complex methods, the DEM can also produce the height information for spatial analysis with less complexity and more effective way. At the present, the DEM is usually based on GRID (regular raster model) or on TIN (Triangulated Irregular Network) concepts. From these two methods, the TIN model is preferred. To some extent, geodesy does not accept the imprecise information as the geodetic data are often viewed as precise data. Nevertheless, it is quite obvious that any kind of geographical information contains imprecision or vagueness. When dealing with uncertainty geographical information issues, one of the most popular applications like fuzzy theories and concepts are often pointed out and taken into account. Fuzzy concepts seem to give wider opportunities to study and understand the imprecise geographical information, as the concepts allow users to model the imprecision naturally and different methods of defuzzifications also give a better understanding of the results. In other words, fuzzy theories, unlike classical theories, support imprecise information to be viewed and modeled to study the vagueness in elevation data more realistically. Fuzzy DEM is, therefore, introduced and developed in this research.