关键词: 面向对象建模方法, UML-G, 空间对象, 空间关系

Abstract: At present, object-oriented technology is widely used in GIS research and software development, besides of the advantages that object-oriented technology brings to software analysis and design, it also benefit the data modeling of GIS. UML-G, an OO modeling language for geographic information applications, is described based on the extension mechanism provided by UML. The extension approaches include stereotypes, tagged-values and constraints. In UML-G class diagram, these three extension approaches are used to define geospatial objects and geospatial relations. The representation in UML-G of four types of objects, i.e. simple spatial object, coverage object, complex spatial object and spatio-temporal object, is discussed. For each case, the model instance is described and proves that UML-G is an efficient modeling language for GI applications. Besides geospatial objects, the representation of spatial relations is emphasized. Based on the analysis of the spatial object property, spatial relations can be regarded as derived properties, so it is not necessary to identify them during the analysis phrase. Based on the discussion, two solutions are given, one can be applied in generic GIS-platform development, and another fit for the specific GIS application development. At the end, future research work of UML-G is listed, which includes the extension for OCL and the other diagrams, such as use case diagrams, collaboration diagrams, etc.

Key words: object-oriented modeling technology, UML-G, geospatial object, geospatial relation