Design And Implementation Of Dem Modeling And Spatial Analysis

Recently, with the bringing forward and development of the concept of "Digital Earth", the three-dimensional geographic information system is being developed greatly as the important part of the concept. The research of 3DGIS involves the GIS, Database, Computer Graphics and Virtual Reality etc. The 3DGIS has broken the limit of 2DGIS to the representation of the spatial terrain and objects on it. And it can give people more real spatial feelings.The content of the paper bases on SEI3DGIS and the application system-GeographicInformation System of Luan River Drainage Area.Firstly, the realization of three-dimensional modeling and display is described in the paper. The Grid DEM model is used in the system to simulate the 3D terrain, and some different methods are used to get the objects model on the terrain. The result is accurate, and with good efficiency.Secondly, the design and development of the spatial analysis module, which is the main application module in SEI3DGIS, is included. According to the typical users' requirement, some kinds of spatial analysis functions based on the DEM terrain data have been realized in the system. During the realization process, the extension of the module is taken into account.In the end, the spatial-property query module is described. In the module, the function of database property query is realized. And the further extension of the system is also considered.