The Design、implementation、integration、application Of Geological Modeling

With the coming of information age, more and more majors do their research using GIS. Instead of the traditional non-interactive display in 2D condition, people hope to describe the perceptual world in a form of interactive 3D image or VR. Faced with varies of phenomenon and space targets in the real world, GIS describes them in the way of abstraction. Although our world is three-dimensional, most business GIS don’t contain the third dimensional information in space data, which has been projected onto 2D environment. Among the reasons, the lack of the suitable model, which can describe the space targets up-ground and under-ground very well, plays an important role; besides, the algorithms of processing and analysis for the three-dimensional spatial information still remains to be improvement.By the contemporary geographic information technology, this paper takes an instance of Xi’an prototype system’s development. Combined with the terrain, geological characteristics in Xi’an and the need to integrate the operation of the underground and up-ground model, this article make a deep search of the model structure, algorithms and other core issues in the development and application of three-dimensional GIS system. The main achievements are as follows:1. Three-dimensional model study. According to the research at home and abroad, it discuss the method for constructing data models and the seamless integration between the different models.2. Design the underground and up-ground three-dimensional data model.To accomplish the operations of seamless integrate and vector cut, the three-dimensional data models are designed on the ground, surface and underground. By focusing aspects conceptual design, logical design, physical design and topological relations, the structure formation model will be described.3. The identification and conversion between different models. Different data models always own their different strengths, thus the integration of different models can solve the problems which the single one can’t solve. However, the core integration technology between the models is to identify and conversion between models. Depending on the structural characteristic of three-dimensional model which is designed, it’s make sure the consistency data structure, complete topology between models, by designing a corresponding conversion.4. The operations of spatial data. Based on the design of this article and the feature of Xi’an, the vector-cut algorithm is designed to meet the need of geological analysis. Combined with this algorithm, this model of ground fissure would be added. At the same time, the virtual drilling algorithm would be designed and implemented.