Hillshading with Contours
Assistant Professor, Department of Earth and Environmental Science
CW Post Campus / Long Island University
720 Northern Blvd.
Brookville, NY 11548
Tel: (516) 299-2652
Professor, Department of Geosciences, Oregon State University, Corvallis, OR 97331
This paper presents modifications and automations of two contour methods devised by Kitiro Tanaka (1896-1973) for hillshading. Tanakas orthographic relief method uses traces resulting from the intersection of topography with a series of evenly spaced, inclined planes, as opposed to the traditional horizontal planes. His relief contour method uses black and white contours of varying thickness on a gray background. With both methods, the tonal variations associated with contours approximate oblique hillshading with the Lambert assumption. Using Geographic Information Systems (GIS), we offer methods to automate these procedures. We also suggest modifications of Tanakas methods, such as creating hillshading effects that more closely approximate those predicted with the Lamberian assumption, and adding layer tinting.