【作者】 张坤；

【导师】 陈学工；

【作者基本信息】 中南大学 ， 计算机科学与技术， 2010， 硕士

【摘要】 等值线图在石油勘探开发、采矿、地质等领域有广泛应用,但由于这些领域经常遇到断层,使得断层附近的等值线追踪结果不能正确反应真实的地质构造。因此本文主要研究了基于三角网的等值线生成方法,并提出了一种分区算法来实现带断层线的等值线追踪。在基于三角网的等值线生成算法方面,本文改进了原有的等值线生成算法。该算法首先在建立三角网的同时保存边界边到凸壳边表,然后求出所有存在等值点的三角形,将其保存在三角形数组中,最后根据一定的规则进行等值线的追踪。通过凸壳边表可以快速地找到开曲等值线的线头,通过判断三角形数组是否为空,可以快速确定是否存在闭合等值线,从而提高了效率。目前约束Delaunay三角网生成算法多数是采用对角线交换的方法来解决三角形与约束线的相交。考虑到断层线的特殊性,如果采用该方法,生成的等值线延伸不到断层线,从而不能真实的反应地质构造。为了解决该问题,本文对已有的约束三角网生成方法进行了改进,即将断层线与三角形的交点看作插入点,再次进行三角剖分。这样处理后再通过本文提出的分区算法估算插入点和断层线端点的高程值,就能得到延伸到断层线的等值线,从而提高了精度,更好的反应了真实的地质构造。在带断层线的等值线追踪算法方面,为了得到断层线上点的精确高程值,同时考虑到断层的复杂性,本文提出了一种基于三角网拓扑结构的分区方法来解决该问题。算法首先把与断层线重合的三角形的边标志为边界边,其次根据组成区域边界的边类型,搜索出所有合理区域和各个区域内部的点,然后搜索与断层线上点在同一个区域的点,通过这些点来插值断层线上点的高程值,最后得到带断层落差的等值线。该算法可以处理各种断层线,并且分区的同时实时保存了每个区域的内部点,避免了判断点在区域多边形的内外,优化了分区。更多还原

【Abstract】 The isoline map is increasingly used in oil exploration, mining and geology application. Because of faults, the result of isoline tracing can not reflect geologic structure correctly in these fields. This paper principally discussed the generation process of isoline which is based on the triangulation model and put forward an algorithm of isoline tracing with fault lines.At the aspect of the isoline tracing based on the triangulation model, this paper improved the original algorithm. In the first place it preserved boundary edges to the table of convex hull when building triangulation. In the second place it preserved triangles to triangle array which have equivalent points. We can quickly search the start point of the open curve and judge closed curve from triangle array, so it improves the efficiency.At present the algorithm of triangulation with constrained lines usually resolves the intersection of triangles and constrained lines according to the diagonal line exchange algorithm. If we use this method, the isoline can not extend fault lines. To resolve this problem, this paper improved the initial algorithm. First it regarded the intersection points not including the endpoints of fault lines of triangles and fault lines as insertion points. Then it did triangulation again with insertion points. Through above process, isoline can reach fault lines and reflect actual geologic structure.At the aspect of the algorithm of tracing isoline with fault lines, this paper realized a partition algorithm based on topology structure of triangulation to estimate elevation values of both side of points on fault lines considering the complexity of fault lines. Firstly, the algorithm regarded edges coincided with fault lines as boundary edges. Secondly it searched all reasonable regions, internal points and interpolated points of fault lines by judging the edge type consisting of region boundary. Lastly we can get isoline with fault lines. The algorithm can deal with all kinds of fault lines and optimize partition by preserving inner points of every region.更多还原