Application Research Of Spatial Data Sharing Based On GML

It is an effective way to use earthquake disaster mitigation information system based on GIS to manage the information of urban disaster to alleviate the losing caused by seismic disaster. In recent years, a lot of departments which are relevant to seismic disaster reduction with city, such as urban construction, electricity, the fire department, etc, have set up their own GIS system in succession. And because these systems adopt different GIS software, their data format is different. In order to fully utilize resources of the existing data and carry on the work of taking precautions against earthquakes to reduce disasters better, one of the most important things for seismologists is to develop earthquake disaster mitigation information system, which is based on internet and has function of spatial data sharing.Geospatial data is the basic source of GIS, which has several characteristics: multi-sources, multi-semantics, and multi-space-times, multi-scales. HTML is disadvantage to describe the structural geospatial data and the implement of geospatial data sharing. Geography Markup Language (GML) brings spatial data sharing to a new age. GML is open and non-proprietary specification used for the representation, transport and storage of geospatial data. It not only inherits characteristics of XML and encapsulates geographic information and property, but also puts forward a foundation for designing data model.With the deep research on XML, GML, SVG technology, earthquake disaster mitigation information system is designed and realized in this paper. The system is composed of three-tier architecture, client, server and database server. The client tier realizes graphics user interface and represents spatial data. The server includes Web server and GIS application server. The former is used to communicate with client-side, and the latter is used to access database server and outputs GML document. Database server is in charge of managing and manipulating spatial data using Oracle 9i spatial.This main content included in this paper are as follows: according to rules and steps of geographic information model, urban earthquake disaster mitigation spatial data model is constructed;the database tables are designed according to the model, and the spatial database based on Oracle spatial is created, which is used to manage and manipulate uniformly geographic data and property;the XSLT is used totransform GML document into SVG document to issue map on Web, this method offers an executable resolution of vector information visualization;with the interaction between JavaScript and elements in SVG map, the client fulfills the geography layers management, zooming, panning and query.