Research On Visualization Of The Target Areas Of Changchun Stratum Information

Since the 1990s, the rapid popularization of modern information technology and the universal application in the world's urban geological work is the new trend. The traditional geologic data analysis and interpretation is expressed by two-dimensional, static form and only a simply description of the ups and downs of space tectonic changes .Compared with the traditional way of displaying strata information, 3D visualization has the advantage of direct viewing, flexibility and acceptance, and can observe the geological structure form in multi-angles.With the development of computer graphics technology and the studying on geognosy, the request on 3D stratum modeling has become stronger. How to achieve the purpose of establishing 3D stratigraphic modeling and visualization analysis have become an important field of research topics, especially for the regional scope of the 3D modeling, the present study is one of the difficult and hot spotsAs to the diversity of engineering application and the complexity of the geological data origin of Changchun city, the requirements on data are presented, the unification of accuracy and simplification, the unification of space and dimension, the unification of partial and integration. By analyzing some typical tectonic, we concluded the principle that the stratum can extend and go out gradually. Examples indicate that principle can applied to many sorts of stratum construction. In the course of building geological bodies 3D model of drilling data, it can be regarded as the basic principle for this complicated model. The principle can be use to test the correct of the modeling and to amend.The distribution of the bores is unevenly. For the large undulating terrain and the baroque stratum areas, a few bores are difficult to achieve accurate formation of strata. In such a case, we quote a concept of"virtual borehole ", which will be bound in model with the actual data to establish a refined 3D stratum model in order to meet the requirement of the actual projects. The so-called "virtual borehole", is using the explanation of the results gotten by other means of investigation and the experience in the long-term geological projects to deduce information in an unknown region. The virtual boreholes have the same accuracy as the actual in establishment of the 3D stratum model. The character of the model generated in the virtual space should be identical with the virtual borehole. It is extremely useful for the complex geological phenomena such as faultage, depositional termination, lost strata, interlayer.By analyzing ,first, we collected the meteorological data and geologic information in the studied area, then, processed the collected information to determine the geological guide bed. According to the urban geologic information collected, using the sequence tiered approach to establish standard sequence system. As the urban drilling information is variety, selecting reasonable bore to be standard in term of the established standard sequence system and to form a standardized bored lithology sequence database. As the main aim of the study is to establish a spatial stratum model for the Quaternary System, the strata in the studied area are not taking as formation to research.The 3D stratum model is established by the drill data. The drills are orientated by using MAPGIC and posited on he geographical base map. According to the base map in the MAP module, selecting the earth coordinates, mapping the border, the drilling data were input to establish the drilling three-dimensional database, and then to be divided into irregular triangular and create TIN. Information will be edited into the GMS, Kriging interpolation is adopted for interpolation, and the results corresponding to the TIN, Using the various strata of the structure of the entities to establish the geologic framework model. After the establishment of the initial model, according to see any need to decomposition stratum section by using solid module, and the existing geologic data and experience of experts explained to improve the model, and gradually achieve accuracy.The urban underground stratum information is studied by using the software of GMS, MAPGIS and so on. The model can be observed in three-dimensional dynamic on the multi-stratigraphic section and achieved a large area of the complex geological content of the three-dimensional visualization of expression. The model can be continued to add new information that the drilling to refine and perfect the model. The construction of 3D stratum model is a further application of urban stratum information systems.