Study On Automatic Generalize Technologies Of Forest Resource Map

This paper analyzed the contents of forest maps, and the common mapping technology. And the author especially analyzed the contents and mapping technology of forest sub-compartment map and forest resource distribution map then the feasibility of forest resource distribution map cartography based on the sub-compartment map. The map scale of forest resource distribution map is smaller than the sub-compartment map. As the map scale changed the contents of map and mapping technology also should be changed, the contents and information of the map are changed. The material map should be generalized properly.After analyzed the particularity of forest resource distribution map generalization processing.The author proposed that the generalization should be based on the environment of forest lands and comprehensive considerate several factors, when carry out the forest resource attribute data and graphic data generalization procedure. The author also discussed what, how and what level should be generalized for the forest resources distribution map.Considered the forest land classification and aggregation rules and merging, displacement, exaggeration, delete problems;this research put forward an automatic generalization process base on geographic information system. Probed into the key technology of automatic forest resources distribution map generalize.With the COM and Dynamical link library (DLL) technology, a program is designed and accomplished for the forest resourcesdistribution map.Combined the cartography operators in a DLL, the program according to the data and export knowledge evaluate and choose proper operators from this DLL.With the forest resources data of Beijing in 2004, at last the author evaluates the automatic generalization program. Researched the information change situation beteewn before and after generalize. When the material data generalized to some small scale the entropy changed from 4.7937 to 4.7585. In this case the results are suitable for the forest resources distribution map. Here are the main content and results of the researching work:1) Based on the related theory, explicitly analyzed the peculiarity of forest thematic cartography generalize.2) Set up the procedure of forest thematic cartography generalization based on sub-Compartment map.Fully summarized the ways and mainly considered rules when under take the generalization practice.3)Based on the environment of the sub-compartment,the generalization practice results are objectively represent the spatial distribution status of the forest resource.4)The way of the program design is based on COM+ and DLL technology, provide a practical scheme for the forest thematic cartography generalize.5)The research designed the forest resources distribution map automatic generalization program,and evaluated the program with its results.