Research and Implementation of Spatio-temporal Data Model Based on Time-varying Sequence of Geographical Events

The geographic environment that has been represented by geographic information systems(GIS) is varying continuously.But popular GIS platforms belong to static systems substantially,and cannot express the dynamic information of spatial entities well.With the increasing demand for spatial analysis functions of GIS,especially for processing capability of multi-timing spatial data,a new spatio-temporal data model for temporal GIS(T-GIS) should be created instantly.Firstly,several typical spatio-temporal data models are compared in the paper.The pro and cons of typical data models can be learned about from the table in the second section of paper.Pointed to these data models,the paper presents and discusses a spatio-temporal data model based on time-varying sequence of geographical events.Secondly,this paper discusses spatio-temporal semantic relationship and topological relationship of T-GIS.The expression of temporal information of the data model preserted the paper is different from the typical data models mentioned above.The temporal information of spatial entities is recorded with time-varying sequence of geographicalevents.In other words,the temporal and spatial information of entities is stored separately in the data model.Finally,according to the character of input and output data sets in cadastral management and land subdivision,the paper extends the functions of popular GIS platform(MapInfo Professional 6.0) in order to demonstrate the efficiency of the new data model.The method is to create two relation tables:one is Event table and the other is Object table(the format of Object table is TAB of MapInfo) in database.All events should be stored in Event table according to time sequence,and spatial entities including spatial and attribute information are recorded in Object table.Through processing the two relation tables,we can display,analyze and query simply spatio-temporal information of entities in land management.