Methods for the visualization of digital elevation models for landform mapping



Digital elevation models (DEMs) are increasingly used for landform mapping, particularly with the growing availability of national and global datasets. In this paper we describe a variety of techniques that can visualize a DEM. We then compare five techniques to ascertain which performs the most complete and unbiased visualization. We assess the visualization techniques by comparing landforms mapped from them against a detailed morphological map (derived from mapping of multi-azimuth relief-shaded DEMs cross-checked with stereo aerial photographs). Results show that no single visualization method provides complete and unbiased mapping. The relief-shaded visualizations are particularly prone to azimuth biasing, although they can highlight subtle landforms. We recommend curvature visualization for initial mapping as this provides a non-illuminated (and therefore unbiased) image. Initial mapping can then be supplemented with data from relief-shaded visualizations. Copyright © 2005 John Wiley & Sons, Ltd.