Design And Realization Of Web Geographic Information System (WebGIS)

GIS(Geography Information System) is a kind of technology, which is combined with computer science, geography, remote sensing, city planning, mapping and land resource management etc. As a product of the development of GIS and information technology, WebGIS is to implement the functions of GIS in Web. With the rapid development of c/s computing mode and network computing, it lays a solid foundation for the implementation of WebGIS. Based on distributed computing platform and expressed by B/S structure, it is the path that GIS penetrates into daily life.The evolvement of architecture of GIS from stand-alone PC to network is analyzed in this dissertation, as well as according key technologies. It studies on the spatial data structure of geography information and analyzes the characteristics and application of spatial databases. The application of middle-wares in spatial database is discussed. Taken ArcSDE as example, which is produced by ESRI Corporation, it studies the storage and management of spatial data.In this dissertation, the conception, characteristics and significance of land value management GIS system is introduced. The network architecture of Windows DNA is adopted in the implementation. With the layer divided properly, it realized the balance of payload and seamlessly connection. Land price management GIS system of Shaanxi province is established with the technology of GIS and it provides dynamic and comprehensible land price information. It provides the policy-makers useful information.Shortest path is one of the major problems in the application of GIS. The theory and algorithm of shortest path in GIS is studied in the dissertation. Especially, the traditional Dijkstra algorithm and heuristic search algorithm are discussed as well as their own characteristics and conditions.At the end of the dissertation, the development of WebGIS is reviewed, and it indicates that coding modes of geographical information and network protocols are the key factors in the development of WebGIS in the future.