Hierarchical Reasoning in Time and Space

The study of spatial relationships has been one of the most active areas in GIS research over the past twenty years. Many formal models have been proposed for the definition of topological or cardinal relationships. However, these approaches often consider space as a static continuum which does not integrate the temporal dimension. Recent progress in spatio-temporal GIS research attempts to extend the representation of spatial relationships to the integration of the life and motion of spatial entities or in other words, the study of the evolution of spatial entities. However, these models generally consider the evolution of spatial entities, that is, entities constrained by a filiation tree. This paper proposes an alternative view of relationships in space and time, that is, we consider independent entities in space and time. The temporal and spatial dimensions are modelled using a hierarchical approach that allows the description of relationships at different levels of abstraction. We show that hierarchical reasoning in time and space supports the identification of modular relationships, generally not identified in existing temporal GIS models, and suggest that their use has promising potential for many GIS applications.