3D Hydrogeologic Modeling & It's Visualization

Aimed at the developing situation of the 3D hydrogeologic modeling & it's visualization, and based on the systematic analysis of various present modeling methods, visualization technologies & spatial interpolation methods , this paper put forward a kind of guiding thought which is suitable for 3D visualization moedling in hydrogeology field. Under the instruction of this thought, it confirmed it's validity through some examples.First of all, it introduced the modeling objects and their geologic character in the 3D hydrogeologic modeling process. For the convenience of later modeling, it classified the objects in the angle of model types.Secondly, summarized the 3D geologic modeling methods and pointed at the character of large area, shallow depth, lack of information existing in 3D modeling data of hydrogeology, the author raised a plan called multiple source information modeling that based on the geological section information when eastablished 3D hydrogeologic model. On concrete data structure, it is better to use vector structure like wire-frame, surface and section-TIN to realize geometric model, while making attributive model, voxel is more suitable. When we considered the technology level of present PC hardwares and softwares, OpenGL is the best tool to realize visualization because it has good expandability and portability, what is more, it can manipulate graphics controller. To construct model it need data, so it listed all the needed data types, also elaborated the generalization principle of borehole data and section dara which are absolutely indispensable.The key step using scatter data to create a 3D model is doing spatial interpolation. Although it is flexible to choose the interpolation methods, there still has some rules to follow. Generally, DSI is more suitable for the geometric model, and the most adaptable interpolation for attributive model is Kriging. Because auto modeling way can not creat accurate model, it need to be corrected by virtual boreholes and assistant sections.Finally, contrasted the character of present 3D geologic modeling softwares home and aborad, known the data storage format of hydrogeologic field, and using the above thought, we chose two softwares named 3D-Grid and MapGIS to construct the 3D hydrogeologic models of north China plain and Heihe river valley, also interpreted the models from professional view.In conclusion, this paper has established fine foundation for both developing 3D hydrogeologic visual modeling softwares and building 3D hydrogeologic visual models.