| Abstract | Contours are very important since they are most widely used for portraying relief on maps.
Given the contours, we can interpret the shape and determine the description of a particular area
or surface since they contain implicitly all the characteristics of the terrain such as breaklines,
summits, tops and valleys. With the advancement of technology and the application of the
Geographic Information System (GIS) to various fields, namely, in urban planning, geological
analysis, route mapping, golf course design, etc., the use of contour map is becoming more
essential. Thus, contour lines which serve as the basis for terrain analysis should be accurate.
It is already known that triangulation is a pre-requisite to contouring. In this particular
study, the applicability of the Delaunay triangulation has been verified for the generation of the
contour lines. Furthermore, it is also noted how the triangles that were formed by Delaunay
triangulation can affect the quality of the contour lines generated. Based from the randomly
located digital terrain points that have been read from the input raster data, set of triangles were
formed and with the application of Lawson's Local Optimization Procedure (LOP) it has been
noted that the triangulation of the set of random terrain points is unique. This criterion requires
that the diagonal of every convex quadrilateral occurring in the triangulation are well chosen, in
the sense that it should make the two resultant triangles as nearly as equiangular as possible.
The study concludes that the number of random terrain points and the formation of
triangular facets by Delaunay triangulation could greatly affect the accuracy of the contour lines. |