| The early topographic maps take "the paper" as the medium. These kinds of paper topographic maps do not only have a very great difficulty in the renewal, but also it easily distorts because of damp, the chemical corrosion. This does not cause the data accurate. Therefore, in January 1998, Gore who appointed American Vice President at that time proposed "the digital Earth'', and this strategy obtained enthusiastic responses of the scientists and statesmen.Because terrain data type is various and the quantity is huge, the data management mode that is made by paper or based on files does not satisfy the user's request Nowadays, the terrain data already has been widely applied to many domains such as the landform simulation, the soil research, the hydrology research and so on. Therefore it has great significance and value to establish the terrain management information system, whose function was stronger and whose operation was simple. Many cities of China are establishing their foundation geographic information system respectively. The topographic map database management system is the important constituent of the foundation geographic information system, it mainly realizes the topographic map's storage, inquiry and retrieval. A number of topographic map management systems use independent GIS platforms, like Arc/Info, Maplnfo and so on. All these platforms have a quite comprehensive GIS function, but they also have some flaws as managing topographic map database, such as the cost price is too high.MapObjects—Java Edition, one kind of ComGIS, has a lot of advantages such as it's cabinet, low development cost, convenience for developing and so on. By using the client server, MapObjects can access the ArcIMS, or use the ArcSDE to connect with large database such as IBM DB2, IBM Infomix, Microsoft SQL Server and Oracle, and it also can update the data by using Java API. As a programming language, Java is famous because it's simple, OOD, distributed, safe, dynamic and so on. Therefore, this paper develop the Chongqing landform management information system using MapObjects—Java Edition and Java combining with Oracle as spatial database. The research results as follows:1. System design. Based on system analysis and integrated with current development conditions, the system has been divided into three modules—the map display module, the data management module and the inquiry module. The map display module mainly shows Tif data, Shapefile data, Image data and shows the elements of topographic map in different layers; The data management module is mainly constituted by map operation, the data renewal and the projection transformation.2. The classification and codifying of topographic map essential factors. We classified 1:10000 topographic map essential factors 17 types, 1:100000 topographic map essential factors 16 types, 1:250000 topographic map essential factors 14 types, and proposed its classified code according to 《the classification and code of the elements of the topographic map on the scale of 1: 500 1: 1000 1: 2000》 (GB14804—93) ,and realized topographic map essential factors management in different layers. And we has established 1: 100000, 1: 250000 topographic databases of... |
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