Geographical model aA Gis database is a model of the real world that can be used to mimic certain aspects of reality C model must represent certain entities and relationship among them o A model may be represented in words, in mathematical equations, or as a set of spatial relations presented by maps or GIS
Nature of geographical model a Models are designed to mimic only selected aspects of reality C A more complex model may or may not provide better answer c Models are used when it is more convenient or it is not possible to collect the information directl a E.g. It is convenient to measure road distance on a map O E.g. The height a forest will reach in 100 years time is impossible to measure directly