Implementation of Object-oriented GIS Data Model with Topological Relations between Spatial Objects

摘要

Traditional GIS (Geographical Information System) data models are focused on the description of the data organizational structure and constraints from single aspect, which are the absence or little relevance of the hierarchy and connotation of data objects. These data models do not match the natural concept of humans about geographical spatial data and also failed to fully consider the spatial relationships and arithmetic operations with the relationship between geographic objects. Object-oriented technology mimics the human way of thinking as much as possible, it appears to overcome the shortcomings of traditional software design methods and improve the stability and reusability of the software systems. Based on the existing GIS data model, this paper introduces the basic idea of object-oriented GIS data model combined the object-oriented methods and the vectorial expression of spatial entities, and describes the definition and implementation of the object-oriented GIS data model. Furthermore, the topological operations between spatial objects have been defined in the paper for the importance of topological relationships among spatial relationships. The topological operations are directly defined in geometry classes by means of methods, and they include Touch, Disjoint, Cross, Contains, Overlaps, and Intersects and so on.