The Discovery of the Basic Terrain Features Based on Integration Technology between GIS and Spatial Data Mining

The computer discovery technology of terrain features in topographic map is a new research project in the world. In this paper the author uses CD-TIN which is constructed on the basis of contour lines to discover and extract terrain features. The author uses improved convex algorithm to construct nonconstrained D-TIN, and then puts forward impactedregion-diagonals-change local adjusting algorithm, and the new algorithm is used to embed contour lines into D-TIN as constrained segments and ultimately construct CD-TIN. We can discover flats and mountanious regions inside topographic map by means of computed normal vector and gradient. In the discovered mountanious regions, terrain features such as the neks, mountain peaks and valleys can be also discovered through the established CD-TIN's data structure and topology relationships.