The Construction Of WebGIS Information System Based On The Geological Disasters Of Wenchuan Earthquake

With the speedy development of Internet, GIS plateform has been turned round toWeb gradually. WebGIS is the product of GIS development which was applied to by Internet and World Wide Web technology. In Geographical Information system, The user can accomplish lots of operations to get much spatial information through each note of the Internet,including getting needed spatial data, Creating thematic maps, doing some spatial information retrieval and spatial analysis. The spatial data has the characteristics of variable resource, patio-temporal, scale and complicacy of obtaining spatial data,which decide its description complexity. There is a technological difficulty that how to realize standard coding for geographical data and break the enclosing between variable Geographical Information Systems. Through using the technology of .NET,ActiveX,SQL Server2005 and Web Service,The paper realize the integration and share of distributed multisource spatial data that is a difficulty in traditional WebGIS.The primary research work in this paper is as following:(1) Study the capability of SuperMap in recognizing, managing and expressing geographical information. To design different layers add of point,polygon and polygon based on SuperMap cored model, And then according to the corresponding relation of variable GIS format and Deskpro, to design and realize transformation from common GIS format,such as CADFile,to ShapeFile format.(2) Study sufficiently that the capability of earthquake geological disasters is made on the relation among earthquake fault,slope,elevation,lithology and rivers using the GIS spatial analysis and the function,realized the sensitivity evaluation of earthquake geological hazards.(3)Analyze the superiority of Web Service in realizing capability of heterogeneous system, then study its application mechanism in WebGIS and design some Web Services for integration of multi-resource, including the service for getting Web document,metadata service for convenient for query, the service for convenient for query,the service for querying and unit Web document and visualization service of earthquake geological hazard information.(4) Based on Web Service technologyto realize a Web geographical information system which is a four-hiberarchy including client,Web server,integration server and distributed spatial data supporter ,and servers are responsable for referring and integrating needed web services to meet the client demands, Additionally,The JavaScript in client help users to complete operations towards the map, such as zoom in, zoom out,pan and so on, by supports a fresh idea to manage and allocate city spatial data in by an active, rational and effective way.