Design And Implementation Of Full-vector Geological Symbol Database

Since GIS is widely used in geology, geological map that mapped by GISsoftware has become the major means of geological mapping. However, the symbolsystem of existing GIS software platform in the map rendering could preliminaryserve the needs of geological professional mappings, but the standardization ofsymbols and the degree of refinement, there are still many deficiencies.Geological symbols are usually more complicated and numerous, especially onexpression of lithologic pattern symbols, due to the existing GIS software is usuallyuse the raster picture to fill symbols when rendering the map, it is difficult toguarantee the clear and beautiful symbol when the map scale is changing, a largenumber of raster picture can slow the rendering speed, and the symbol data quantityis large. At the same time, symbol system of the existing GIS platform are relativelyindependent, the aspect of symbol sharing also cannot meet the needs of users.Based on the above analysis, we need to design a full-vector geological symboldatabase which could conform to the geological standard in our country, it shouldhave simple and convenient storage and less data redundancy, also can ensure thequality of rendering. Through the analysis and summary of the geological standardin our country-Geological Symbols Used for Regional Geological Maps, this paperputs forward a geological symbol database to meet the needs of geological mapping.The symbol database is designed and develpoed without any GIS system, toimplement the cross-platform and symbol sharing. This paper mainly completed thefollowing work:(1) By adopting the idea of vector data structure and graphical element method,combining of full-vector graphical elements, controling by attribute, renderingperiod and symbol template, the full-vector geological symbol database has been setup.(2) According to the current geological standards, we extract the graphicalelement and parameters from the standard, product symbols, implement thestandardization of geological symbols. (2) On the basis of characteristics of symbol database, we use the access databaseto store symbol information, and design a general access interface of database, fordifferent mapping software to use symbol database, realizing the symbol sharingsand cross-platform applications of symbol database.(4) Combined with the standardization of the Marine cartography system projectand its related application, the symbol database has been tested, the full-vector andstandard geological symbols, as well as a cross-platform application has beenimplemented, and the requirement of symbol effect and the symbol databasemanagement has been achieved.