Modeling Dynamic Beach Objects Using Spatio-Temporal Ontologies

Abstract

This study models geospatial landscape features using spatio-temporal ontologies. A spatio-temporal ontology explicitly specifies a dynamic conceptualization of real world objects. Spatio-temporal ontologies are applied to the Isle of Ameland, relating beach nourishment to elevation, vegetation and wetness. The spatio-temporal ontology contains full membership functions for crisp objects, partial membership functions for fuzzy objects and temporal membership functions for dynamic fuzzy objects. The temporal membership functions include seasonal changes of vegetation and daily changes in wetness. Quality elements are discussed by means of a quality matrix, where ontological features (i.e. objects, attributes, relationships) are projected against their qualities. A sensitivity analysis showed that the calculated beach nourishment volumes are practically insensitive in relation to assumptions on the temporal membership functions. Spatio-temporal ontologies are shown to extend spatial ontologies to model dynamic processes in environmental studies in a more realistic way.

Keywords: Ameland, beach objects, ontologies, quality, sand suppletion, space-time