Nowadays, spatial data are distributed over several existing systems (geographical information systems, database management systems or file systems). To achieve the sharing and exchange of existing data between different departments semantic heterogeneity between data from different component systems must be resolved. Without knowing the semantics of data (i.e. their meaning) it is impossible to use or integrate data appropriately.

Therefore, there is an urgent need for research to represent the semantics of data at the conceptual level, utilise this semantics when integrating heterogeneously represented spatial data from different sources, and resolve semantic conflicts between data from different local systems. These issues are the focus of the project MIGI.

The project will result in a framework for specifying the semantics of data in terms of well-defined categories and a predefined measure for each category. This semantics will be stored explicitly in a data dictionary and utilised when integrating data from multiple sources.

Furthermore, the integration of integrity constraints which are applied in local systems as well as the implementation of global integrity constraints using database technology will be considered. The resulting integrity module shall be used to implement spatial integrity constraints within the database management system.

The project MIGI is an interdisciplinary project of the Department of Geography and the Department of Computer Science at the University of Zurich.