Formalization of Spatial Constraints

Constraints are inherent in most spatial datasets. However, they are often not defined explicitly and therefore cannot be enforced. This leads to the need for an explicit formalization of spatial constraints. In order to identify the diverse formalization requirements, previous research on constraint classification and usage in both data integration and generalization is analyzed. Also different approaches for modeling and enforcing constraints are presented. As a result from the analysis, a flexible and expressive constraint formalization based on the Object Constraint Language (OCL) is proposed. It is then shown how the so-called GeoOCL is able to satisfy most of the identified formalization requirements.