Based On The Three-dimensional Visualization Of Digital Elevation Model Zhaopingtai Reservoir

With development of water conservancy informationalization, Geographic Information System (GIS) is used more and more because of its strong abilities in analyzing , managing and displaying spatial data. Digital Elevation Models (DEMs), as main data of GIS, play great role in this process. So, in this paper, some methods of creating DEM and interpolating computation are summarized and studied. After scanning original topographical maps, vectorization, and taking consideration of adding topographical characteristic lines, high resolution Triangulated Irregular Network(TIN) is attained which can be converted to grid DEM. After having been compared elevations of some points derived from DEM with original point's elevations of the map, the quality of DEM is approved reliable.Topographic factors are very important and useful to explore information deeply. Therefore, some factors are studied and drawn based on DEM. Computation of reservoir volume is rather a hard and time wasting work with traditional methods. However, it can be very convenient to calculate volumes at any water level by the means of TIN. Then some problems about visibility analysis are discussed in the paper, including point-to-point intervisibility analysis and area visibility analysis.Due to advantage of Virtual Reality technology, 3-dimension visualization of ZhaoPingTai reservoir is achieved by combining Active Server Page (ASP) and Virtual Reality Modeling Language (VRML), which can provide many functions such as roaming, rotating, flying and walking in an virtual situation, displaying data and maps derived from spatial analysis, and also querying through Web. To keep browse through pages quickly, compression technology is used to handle with vast data.