ABSTRACT
Geographical information system (GIS) is an information system where the geographical locations of the phenomena are stored, enabling the retrieval and processing of geographical information.
3.1.1.1 Data Models
Traditionally, the geographical information is modeled considering the object data model or the field data model. The phenomena that exist only on a limited region of the geographical space are represented by objects whose position in the geographical space represents their location. Depending on the type of phenomena to be represented, they may be modeled as points, lines, or areas (see Figure 3.1). This data model is known as the object data model and is appropriate to represent, for example, roads, administrative regions, or crops.
