Designing Elevation Color Schemes for Representing Mountainous Terrain: A Demonstration Using ArcMap and Photoshop
Eugene Carpentier III, Dr. Aileen Buckley, and Mike Renslow
Department of Geography
University of Oregon
Eugene, OR 97403-1251
Digital elevation models (DEMs) are one of the most common data sources used in modern cartography. DEMs provide a base data layer for depicting topography, which most map-readers can intuitively understand. With the use of hillshading to produce continuous tonal variations that simulate the appearance of irregular surfaces, DEMs can create a realistic landscape that starts to create a sense of place for the mapped area. When combined with layer tinting, when we shade the area between contours, we can create highly informative and visually striking representations of the terrain's visual characteristics. Color schemes for layer tinting can be either classed, which results in a range-graded representation of elevation, or unclassed (that is, continuous tone), which may sometimes be the logical choice if depiction of the complexity of an area is the goal. In either case, colors must be chosen carefully in order to achieve an appropriate representation of the landscape being mapped. Local environmental conditions should be taken into consideration when choosing layer tinting color schemes. Climate and land cover are closely related to elevation, and these environmental conditions can be captured as part of a layer tinting color scheme. For example, lush vegetation in rainy areas at lower elevations can be shown in dark green that contrasts with gray or brown tints symbolizing bare ground in the upper elevations above the tree line. A color scheme used for mapping an area in the Pacific Coast Range of Oregon, which is a high precipitation, dense vegetation range, would not be appropriate for mapping the same elevations in the Eastern Cascades or the High Desert which lie in a rain shadow. The use of color in representing elevation can greatly influence how map-readers perceive a place. In this demo, I will be using ArcMap and Photoshop to manipulate LIDAR-derived DEM data to illustrate the use of hillshading and layer tinting, as well as the choices in selecting appropriate layer tinting color schemes, to create visually compelling representations of mountainous terrain.