A model for expressing topological integrity constraints in geographic databases

Abstract

A major reccuring issue in spatial databases is that of handling topological relationships. Although topology can be determined from object positions it is often explicitly stored in geographic information systems for reasons of efficiency and integrity. No formal database models for expressing topological relationships at the conceptual and logical levels are available. This paper describes such a model by defining geographic objects, geometric types, and elementary spatial operations and relationships. The model can be used to express topological integrity constraints, to define geographic object classes and to express spatial queries. Examples are given on how to use the model for the whole cycle of design and development of a geographic application, including requirements analysis, conceptual and logical modeling and implementation.