Extracting And Expressing Change Information Of Settlements In Spatial Data Updating

The problem for actuality of spatial data become increasingly prominent, and caught theconsumers and the government’s high attention. Therefore, spatial data updating has graduallybecome the main task of spatial data production departments. In order to realize the quicklyreal-time updating, the maximum satisfy people demand for actuality of spatial data, incrementalspatial database updating method has become the current hot topic in the study of spatial databaseupdating. Extracting and expressing change information as a key technology in incremental spatialdatabase updating method, its efficiency and automation level is still relatively low at present,difficult to satisfy the needs of the current spatial data updating.In view of this, according to the spatial database updating application and internationalacademic frontier theories and technical problems, on the basis of summarizing predecessors’research work, this paper discusses extracting and expressing change information of settlements inspatial data updating. In summary, the research content and main innovation points are shown asfollows:1. Research on classification and judgment of graphic data delta. In order to satisfy the need ofspatial data updating for "difference", the concept of graphic data delta is advanced.8kinds of basictypes of graphic data delta are classified on the basis of the basic concept of graphic data delta. Athree-level judging method for graphic data delta is proposed, which is based on the matchingmethod, dimension of the graphics and graph intersection algorithm. A formalized expression modelof graphic data delta is advanced.2. Research on matching method for settlement. On the basis of the analysis for the currentmatching methods for settlement, the improvement of the current matching methods is achieved. Anew areal settlements matching method which is based on the protection of force diagram wasestablished.3. Research on classification and judgment of spatial change. The current classifications ofspatial change are only for single geographic entity, cannot enough to describe multi-entities, andalso in reality some changes of geographic entities are the results of multiple space change types.Therefore,15spatial change types are given on basis of the number of settlement entities andcomplexity of the space change. A new judging method for spatial change is proposed.4. Research on expression and classification model for change information. A new expressionclassification model for settlement change information based on spatial change, dynamic updateoperation and graphic data delta is proposed for making up the deficiency of the current expressionmodels. The relationships among spatial change type, dynamic updating operation and graphic datadelta are extracted through the classification of spatial changes. Also the settlement change information types judging rules base is established. Finally, the formalized expression of differentsettlement change information types is constructed.5. An extraction and expression for settlement change information experimental system isachieved. Taking the same scale and different period spatial datas of settlements as experimentsubjects, the extracting and expressing change informations for settlements is realized. Thefeasibility of the theories and methods is verified by the experiments.