Research On Algorithm Of Isoline Tracing With Fault Lines

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.