The Research Of Building Geographic Ontology

Ontology, originally a philosophical concept, it is not only the interesting problem of philosophers, but also has gained more and more attention among researchers in the field of computer science recently. And it is applied to different fields such as Artificial Intelligence, database theory and computational linguistics, its advantages in these areas have the initial signs of clues.Ontology is not only given more attention in the field of computer science, but also in GIS. The importance of geographic ontology has been received from the last 90's. At present, many foreign experts and research institutes are engaged in researching geographical ontology and do some groping work. But few experts refer to this problem at home.There are rich geographic concepts which are related to each other in the geographic information. Ontology is very significant in the fields such as concept model of spatial information, sharing and interoperation of spatial information. All those need the research of geographic ontology from the level of geography. Its most important significance is to enrich the semantic theory of spatial information.Geographic ontology is a very complex and intricate concept. As a philosophical concept, ontology has the most ambiguous meanings, and it is first introduced into information science, then into the field of GIS. When many experts begin to research geographical ontology, they just transplant ontology concept of information science into GIS, not consider the particularity of geographic information itself. And it is the essence of geographic ontology.In the paper, begin with the difference of geographic ontology and information ontology. Then the format representation of geographic ontology and application in GIS is illustrated in detail. The main research work is divided into parts as folio wings:1. On the base of information, the information reflection, special characteristics of geographic ontology are reviewed. And it tries to build the basic theory system of geographic ontology, which helps to understand the researching field, meaning and development direction of geographic ontology. Ontology is different in different disciplines, and geographic ontology is the development of philosophical ontology and information ontology. Geographic ontology is the study the concepts of the meaning and relationships of layers in geospatial information which are on different levels and about different applications, and gives the concept of semantic logo. Spatial ontology is different from general information ontology because geographic ontology has not only the relation of parent class and child class, and many complex relationships such as location, topology, and mereology. In a word, besides common attribute characteristics, important spatial character cannot be missing in the geographic ontology.2. On the basis of summing up the present methods of building geographic ontology, this paper concludes that the exsiting methods can be utilized synthetically to construct geographic ontology. The most difficult to build geographic ontology is not how to choose the appropriate method, but how to determine the geographic concepts, the relations among concepts, especially the properties of concepts. Although there is no recognized Ontology design and evaluation tagging, we have been recognized that building ontology needs the participation of the experts in the fields. In comparison with other languages, the biggest advantage of OWL language in the expression of its rich semantic information can be well reflected the attributes of the body, and it is the ideal language to describe ontology. There are some limitations when we used OWL to describe the spatial characters of geographic ontology. This paper proposes to construct some formal axioms about spatial properties and spatial relations with the help of three theoretical tools, which are mereology, location theory and topology. And then add these new axioms to the OWL axioms to build geographic ontology which can represent its spatial properties.3. The theoretic research of geographic ontology is hot, but it is seldom practically used. The application of geographic ontology is still a very feeble step. In this paper, an application model of geographical ontology is explored to design, and the ontology visual editing tool Protege is used to build a geographic ontology "Jilin area."4. A geographic ontology system is a conceptualized knowledge system and a display of the formal standard in the specific application areas about spatial information science. The data exchanging of GIS and the outside is easy with the help of the description and the reasoning and enquiries to the concepts expressed by geographic ontology. Because of the rich semantic information and OWL expression which is based on description logic, then GIS using geographic ontology is capable to reason. Finally, Jena inference engine, successfully achieved "Jilin area" horizontal, vertical enquiries, which verified the use of geographic ontology can be realized on the GIS geographic information semantic query and retrieval of the feasibility.Geographic ontology is a very complex concept, and its research in geographic information science is very complex, too. Despite the geographic ontology has a wide range of potential applications in geographic information science, the research is still in its initial stage. In addition, the application of geographic ontology is always a problem, and truly meaningful and effective application is rare. It is a long-term research process to develop a practical GIS driven by geographic ontology, and ultimately achieve semantic interoperation.