Posts Tagged ‘map message’

Less is More – Don’t Default to Shaded Relief

Saturday, July 5th, 2008

montana map gene thorp wash post

My colleague Gene Thorp has a good map in today’s Washington Post showing land ownership in Montana near Missoula. The accompanying article by Karl Vick is headlined Closed-Door Deal Could Open Land In Montana Forest Service Angers Locals With Move That May Speed Building. (The Washington Post, July 5th, 2008.)

Here are the first two graphs of the story:

MISSOULA, Mont. — The Bush administration is preparing to ease the way for the nation’s largest private landowner to convert hundreds of thousands of acres of mountain forestland to residential subdivisions.

The deal was struck behind closed doors between Mark E. Rey, the former timber lobbyist who oversees the U.S. Forest Service, and Plum Creek Timber Co., a former logging company turned real estate investment trust that is building homes. Plum Creek owns more than 8 million acres nationwide, including 1.2 million acres in the mountains of western Montana, where local officials were stunned and outraged at the deal.

And another key graph:

That same impulse drives a different kind of land deal in the area: The buyers are the Nature Conservancy and other organizations that purchase desirable private land to preserve it. Since 2000, the groups have paid Plum Creek market rates to secure 280,000 sensitive acres in Montana alone.

When drawing maps of mountainous areas cartographers often get over-excited about adding relief shading to indicate the shape and height of the terrain in question. This is often appropriate for a reference map but on other maps the relief can be simply gratuitous.

When relief shading is not needed to understand the story and it may muddy the picture by creating distracting visual noise that interferes with communicating the map’s message. Just because the cartographer knows how to create the shaded relief or has a new wiz-bang data source or software program to do so does not mean relief shading should be added to the map.

By removing the relief from this map and choosing to show the Forest Service land in a muted olive green instead of glaring green, the red and black of the private land ownership pattern is allowed first visual prominence, thus strengthening and clarifying the map’s message.

Finally, the map’s message is clearly set forth in a prominent and clear legend. The map reader knows there are two primary and 1 secondary element to examine and compare on the graphic. A context map shows where in Montana the detail is located. Other features have been added for orientation, such as the Rocky Mountains label, Glacier National Park, and the call-out pointer box for Missoula.