DIGITAL ELEVATION MODEL APPROXIMATION FROM STREAM NETWORKS: A REVERSED APPROACH

Abstract. The delineation of stream networks and catchment areas is one the most common applications of Digital Elevation Models (DEMs). In this article, an innovative reversed approach for the approximation of DEMs from stream networks is presented. As a fundamental preprocessing step, the stream networks are sampled with a set of points. Then, a Delaunay triangulation and Voronoi diagram are used to extract the skeleton (medial axis) of stream networks as an approximation of the catchment areas. The catchment areas contain implicit information that is representative of the terrain, and so the elevation points can be extracted along the catchment area boundaries. Furthermore, we employ the stream orders to enrich the elevation data set. Finally, the elevation points are converted into an elevation grid through a raster interpolation method. While an approximation approach, the results show that the proposed method achieves the desired results.