Research On Three-Dimensional Model And Visualization Of Hydro-Geological Structure

Traditional methods of hydro-geological significantly advanced the direction of groundwater science to the development of quantitative by analysis evaluation and management of based on single model.the expression and process of hydro-geological information is two-dimensional(2D),the vertical information abstracted as a property value, the essence is expressed the three-dimensional(3D)hydro-geological phenomena onto a2D plane, the approach is called2.5D or pseudo3D, it describes the hydro-geological structure poor and can not reveal the spatial variation and different for researcher to understand the hydro-geological condition completely and accurately.3D process has become urgent, it urgent to establish3D visualization and spatial information system based on data and3D model to solve complex information management problems of groundwater system of different users.3D structure of hydro-geological model and visualization is an inevitable trend of computer application in hydro-geological,it becomes hot cutting-edge interdisciplinary issues of engineering geology, digital geology and computer science. How to generate volume data of groundwater by3D model based on hydro-geological information and express by graphic and image, this significance for researchers to understand geosciences data and reveal the inherent law of groundwater movement.On account of the above understanding, the paper is unfolded3D data, model, topological relations and model operation algorithm of hydro-geological structure. finally, made a test,the work made progress and innovation in the following parts:1. Elaborate concepts of GIS spatial data model review and classification the current situation of3D model, summarizes characteristics of various types of model and adaptive discusses issues of3D data model, prepare a theoretical basis for3D hydro-geological structure2. Construct hydro-geological structure visualization and analysis system based on DEMs-Generalized Tri-Prism(GTP).propose an improved growth algorithm to DEM construct, it can handle missing strata, pinch, etc. the formation of virtual drilling algorithm.3. Study variety cutting situation of GTP. To ensure the consistency of volume structure by decomposition of the triangle, if a line intersect with triangle, there are five situations according to the other side of the triangle vertices and edge, do not consider segment coincide with an edge4. Take into account the complexity of the fault structure of hydro-geological and sparse feature points of control borders, propose a method of3D modeling including division faults, the method build the fault equation and trend surface of ground level, obtain the cross-segment of fault and ground level, discrete the cross-segment according to a certain space, connect to discrete points in adjacent layers to obtain virtual drilling, the virtual and actual drilling hole to store in the same data structure and model5. Elaborate discussion is given to generation contour based on drilling data including judging, tracking and linking of contour point, in order to confirm the contour,the paper bring forward to tracking-linking method of tracking contour. Experiment show the method can avoid uncertainty tracking.6. Finally, verify the3D model and algorithm, exploit3D structure of hydro-geological information system by object-oriented with Open GL in ArcGIS9.2, example verified in GUANZHONG Basin.