The Research And Practice For Representation Of Spatial Data In WebGIS

With the rapid development of network and computer and special technology, the traditional GIS is evolving to WebGIS. The development of the network is making WebGIS a hotspot in the GIS research fields. Through WebGIS, a large number of clients can get various geogiaphic information services. But WebGIS is facing new challenges for further improvement, which can solve the open problem etc. about WebGIS. As a new web technology, XML brings new opportunity for Web GIS.At first, this paper analyzes the major difficulties and problems about WebGIS based on XML, and then puts forward the solution of WebGIS, and discusses the main problems needed to be solved. Secondly, this paper puts great emphasis on the application of the new web techniques in the field of geographic information, and studies deeply on the XML-based WebGIS technique. The present paper transfers spatial data utilizing the preview of the data, based on XML, and partitioned models, referring to GZIP compression method widely used under Linux.The paper designs the data translation engine which can transfer multi-source spatial data to GML and GML to SVG, so solve the problems about multi-source spatial data integration and sharing. This paper puts forward the SVG-based display project of map at web client, and represents the method to describe map symbols, so it would solve the problems about multi-display and inter-operation of map at web client. Lastly it analyzes the general WebGIS and designs the WebGIS server with ArcIMS9.0 of ERSI. Though ArcIMS have some basic functions ,such as zoom and pan,it can not meet various requirements. So this paper uses ArcXML based on XML to furfer develop ArcIMS.The model of XML-based spatial data transportation, the model of GML and SVG-based multi-source spatial data integration and the method of SVG-based map symbols describing and the visualization of map data and the method of using ArcXML develop ArcIMS are put forward in this paper have many signification to the new WebGIS technology.