The north arrow, whether it is fancy or unadorned, has the sole purpose of illustrating the orientation of the map to the viewer. Yes, it is true that most GIS maps are already oriented with north at the top of the layout. However, there are certainly instances where this is not the case and therefore it is standard practice to include the north arrow. Its inclusion on static maps is almost always warranted. Nautical charts and other orienteering maps should show both true north and magnetic north. In fact, these types of maps usually illustrate the directions on a compass rose, rather than
36 GIS Cartography: A Guide to Effective Map Design
a north arrow, which shows at least four, and sometimes more, cardinal directions. Do not include a north arrow on any map that uses a spherical projection, such as Mercator-based web maps. North is not a constant in those projections and must instead be indicated with graticules.
Best practices: Keep the north arrow small, simple, and unobtrusive for most modern layouts. Historical visualizations or other unique situations may warrant a fancier, bolder look.
Placement: North arrows are best left in a less conspicuous area of the layout. Sometimes you might use one to conveniently balance out some other element. Grouping the north arrow with other ancillary map information such as the scale bar and legend is another common practice. In a very small layout meant for a slide or in an in-line report graphic, the north arrow can be placed directly on the map element, in a corner, perhaps with a box of contrasting color behind. This is a technique used sometimes in 8.5-inch by 11-inch layouts and more rarely on larger layouts. The larger layouts tend to display north arrows outside of the map elements and grouped with the scale bars and other supporting information.
Style: For some reason, we geoprofessionals (and, indeed, cartographers as a whole) have not developed one standard north arrow that everyone uses. Instead, there exist hundreds of the things out there to choose from, in all manner of styles. And even with that, geoprofessionals still sometimes get the idea that each company or department ought to develop its own. It is almost like a logo in these cases. And to this I say, well, why not? It is fairly easy to design one yourself and it will further help your cause to put a unique stamp on your map.
As mentioned earlier, the trend in mapping design has been going toward simplistic north arrows for some time. The context and style of your overall layout will help determine whether you should stick with this trend or branch out to a fancier style (perhaps you are displaying historical data, an archeological dig, or some other type of map that may lend itself to a less modern-era north arrow).
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