Technique And Practice Research On Land-use Data Generalization

Land-use data,as an important part of geographic data in GIS,highlight the characteristics of geographic phenomena involved in land-use field. The generalization knowledge of land-use data includes the map knowledge that is used to represent land-use data as well as nature and distribution rules of geographic phenomena described by land-use data.Land-use data generalization,as one of data operations in GIS,provides multi-scale or multi-resolution data for some applications.Generalization should take into account graphic knowledge,semantic knowledge,procedure knowledge and structure knowledge,and make knowledge rule with generalization operation both it benefit by association together, valid combination.Based on the current researches , this paper analyses the main content and characteristic of Land-use data generalization.Under the guidance of generalization theory and principle, adopt the representation of generalization knowledge with Production-Rule method from artificial intelligence,combine generalization knowledges with generalization oprations.Establish a generalization index system facing the Land-use data factors.Based on the studies of theoretics, MAPGIS 6.5 as GIS envirement, Microsoft Visual 6.0 as second development envirement, Develop the auto-generalization modules:Line-Selected module , polygon -generalization module and balance of area module.Itemize the design thoughts and interfaces and functions of evry module.At last,this paper takes the land-use data of 14 regions of BeiJing as source datas, to build an experiment system and proceed generalization fulfillment application for 1:50000 and 1:100000 and 1:200000 three kinds of scalese, summarize and appraise the data generalization result for the three scalese. These resules can prove that this experimentation is feasible.