The Study And Application Of Component -Supported WebGIS Based On GML

Geographical Information System (GIS) is a software system, which can represent the spatial data and the property data of the earth in a digital way. A standard GIS should support the common functions such as input, store, show, retrieve and analyze the spatial data and the property data describing it.WebGIS is a Network-Oriented GIS. It can provide a lot of internet applications with the capability of GIS functions via Web, including the retrieve, analyze and show of spatial data, etc. GML is gradually accepted by people as an XML encoding for the exchange and storage of spatial information. It is obvious that GML-based ubiquitous WebGIS will have a bright future both in application and in market. In this paper, before analyzing and comparing the common used models of WebGIS, ActiveX model is selected to construct a ActiveX toolkit of GIS based on GML, namely TJU_GIS .It incorporates a lot of successful design and implemental experience of popular GIS.In short, TJU_GIS is a WebGIS based on ActiveX, COM/DCOM, implemented with VC++. In order to implement the interoperatabilty, GML was acted as the standard exchange media. Finally, the design strategy of an intelligent descion-making system based on the TJU_GIS and GPS for the need of Emergency Center of Tianjin City was proposed.