Construction And Application Of WebGIS Based On GML & Web Service

Distributed network technology provides a hardware foundation for GIS spatial data sharing and exchange. With the development of object-oriented database technology, it is possibly to store and manage a mass of spatial data. GIS sharing becomes essentially while GIS is being widespread applied. An open and easily visited GIS will be advantage to communicate information among departments and achieve sharing data and services.Geography Mark Language (GML) is used to describe the spatial data in this paper. Then it studies on the organization, storage and management of GML data by integrating XML database technology. On the basis of all above, the paper tries to solve the questions existing in present WebGIS, such as difficult to share information, bad to extend, hard to integrate with other information manage system, and so on, by using GML, Web Service and SVG technologies. Research details follow by:(1) By deeply study on the GML specification and several common GIS data formats, the paper has finished the transformation form these common data to GML data. The article considers that a GML data transformation service constructed by Web Servicecan realize the sharing of GML data transformation function.(2) The comparison study on the original and relational storage of GML spatial data.This paper compares two methods XED and NXD used to storage GML data. It concludes that storing GML data in XED is better than in NXD when GML documents are smaller. However, when GML documents increase and multi-records are processed,native XML database shows its better expanding and the superiority.(3) Research on the application of GML and Web Service in WebGISThis paper constructs a WebGIS framework that describes and stores geography information with the GML specification, uses SVG in the client to display map, accomplishes functions of GIS system by using Web Service. In the end, the conception is proved feasible by seawall real-time management information system, which has initially solved the questions of distributed multi-sources data sharing and interoperability among seawall management departments.