Research On Spatio-temporal Retrospect Of Geographical Feature Based On Event-tree

The issues on retrospect of spatio-temporal objects is always focused on in the GIS domain, and it is of great significance in T-GIS. The retrospect of spatio-temporal objects is referred to returning the historial state, not only realize the function of real-time monitoring but also provide vary data which covers both history and actuality. This kind of data is helpful for decision-making department to contrast, analyze, make statistic, summarize, forecast the history, actuality and future data.Much valuable knowledge may be extracted from the retrospect data. Currently, it is necessary for GIS to provide a temporal analysis as well as demonstrate the evolvement process of geographic entities to find out the development rules in lots of application domain such as cadastral alteration, environmental monitoring, disaster relief, traffic management.So far, the study on the retrospect of spatio-temporal objects is still in initial stage with shortages including that above all we are not able to figure out an appropriate point for combining the spatio characteristics and temporal characteristics, that is to say there are lack of a spatio-temporal connection mechanism, secondly much redundance in data or not according with the work habit or spatio-temporal information is not consistent with the expression of the logic of human cognition......For these mentioned shortages, this paper proposed a feature historical retrospect schemes based on the event-tree. Begin with connection between the event and feature, this paper firstly introduces that the event caused the changing operation. To describe the event and its storage, the paper proposed the event system, which is including that first it proposes the event-tree index system, secondly consanguinity coefficient Edna is also proposed to quantitate the relationship between events. Then the paper analyzes and concludes the general geographical feature change types; give the expression and description rules to each type of change. Finally, according to analyzing the essential relationdship between the event and change time of the feature, the vary restriction spatio-temporal connection methods are proposed in condition of the event becoming the temporal expression, that is to say, to describe the occurrence and processing, we need to record a series of change operation as a key point or the important action of the event, realize the query function of features and events for two-way, then it realized the geographical feature spatio-temporal history retrospect scheme based the thread that is form the event to the change operation and to the feature status.