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50 Number 43, Fall 2002 cartographic perspectives cartographer must put more physical information than ever before on a rasterized base map using unfamiliar techniques. A light touch is required. For example, applying an embossed forest texture on a map any heavier than a mere hint creates distracting noise that obliterates shaded relief and other raster information below (Figure 6). To help see whether the merged physical elements on a realistic map are in graphical balance, try viewing the map on screen at large and small scales. A map that may look perfectly legible at any given spot at 100 percent scale may not work as well when viewed in its entirety at thumbnail size, and vice versa. The objective is to create a map that appears realistic and legible at both macro and micro scales. The design of cartographically realistic maps depends heavily on a reader's observations and perceptions of natural phenomena, particularly when choosing color. Even USGS topographic maps, which are quintes- sentially conventional, use earth brown for printing contour lines, light green for forests, and blue for water. Determining the degree of literalness in which to portray natural phenomena on a map is an imprecise art. A flexible design approach is essential for success. The cartographer must be mindful that the unrestrained pursuit of cartographic realism can yield unsatisfactory results, and that even realistically designed maps some- times need to resort to conventional solutions out of graphical necessity. For example, to an observer deep in the Grand Canyon, the silt-laden Col- orado River is the same color as the terra cotta landscape through which it flows. Showing the Colorado River and Grand Canyon topography in their natural colors on a map would camouflage the river from readers. In a pragmatic nod to cartographic convention, the compromise would be to depict the river as an impure shade of blue. This section briefly describes specific techniques used by the NPS for mak- ing more cartographically realistic maps. Aquafication The depiction of hydrography on conventional maps is usually a perfunc- tory exercise. Drainages and shorelines are drawn as vectors shown as uniformly thin blue (or cyan) lines, and water bodies are filled with a flat tint of the same color. Hydrography produced in such a workmanlike manner appears mechanical and is discordant with other physical ele- ments on the map. By contrast, on maps designed with cartographic realism hydrography is given a softer, more natural appearance. The idea is for the hydrogra- TECHNIQUES "The cartographer must be mindful that the unrestrained pursuit of cartographic realism can yield unsatisfactory results, and that even realistically de- signed maps sometimes need to resort to conventional solutions out of graphical necessity." "The depiction of hydrography on conventional maps is usually a perfunctory exercise." Figure 6. Grand Teton National Park, Wyoming. (left) Conventional shaded relief. (right) Land cover textures embossed onto the shaded relief surface.

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