An Ontology-Based General Multi-scale Conceptual Model and its 3D GIS Application

As an important characteristic of geo-spatial elements, scale has become an important aspect in GIS study. However, the existing algorithms mainly solve scale generalization problems of some specific types of data in 2D, which are not suitable for multi-elements integration of general GIS environment, especially in 3D GIS. With the help of ideas and methods relevant to ontology, the ontological significance of the general multi-scale conceptual model is analyzed, and a scale-extended geographic ontology structure is defined. Through mining the domain essential content of geo-spatial elements multi-scale generalization, the functional classification and the definition of scale behavior operators are proposed. A general conceptual model is established in the form of category-operator-data-relation quadruple which is explained at the application ontology level. In order to apply automatic generalization with the model, an Agent model is adapted, as well as its processing. At the end, an example is put up to show an intuitionistic scale generalization process in a typical 3D GIS environment. The conceptual model is adaptive for different kinds of 3D geo-spatial elements, and the new Agent-based multi-scale generalization method is effective and fully automatic in 3D GIS applications.