Study On Spatio-Temporal Data Model In GIS

Space, time, attributes are three basic characters of geographic entities. The Traditional GIS only involves the space and attributes dimensions of the geographic information, but weak in description and expression of the time dimension. To organize, store and manage the complete description of geographic entities effectively, and express changes of entities over time, the study on the spatio-temporal data model that can integrate with time and space data becomes a hotspot in GIS.In the first place, time, space and spatio-temporal changes are analyzed, and some key issues in spatio-temporal modeling such as features of time, space, spatio-temporal changes and relationship between time and space are discussed in this paper. According to the analysis, the understanding of the spatio-temporal semantics is deepened. Then, this paper reviews the study achievements of spatio-temporal data model currently and proposes a event-based object-oriented spatio-temporal data model in summary of the existing spatio-temporal model. The author abstracts and makes models of geographical information from three levels:conceptual model, logical model and physical model. Meanwhile, the event-based spatio-temporal data incremental updating mechanism is also studied in the paper.At last, this paper takes the forest resources management as an example to build a model of the spatio-temporal process of sub-compartments which is basic unit of forest resources based on the extended relational database, and test the validity of the model by the achievement of spatio-temporal query and history reappearence.