Burned by the EPA

Heading outside tomorrow for Independence Day (I cannot imagine I have any non-US readers yet)? Be sure to check out this map on sun exposure, before you step outside…

Found at EPA Sunwise: http://www.cpc.ncep.noaa.gov/products/stratosphere/uv_index/gif_files/uvi_usa_f1_wmo.gif

Quick! Which areas are going to have the highest UV levels? No, it’s not the Upper Midwest and Canadian border, despite those areas being fire engine red and practically flashing “DANGER! DANGER!” It’s the light blue areas in places like Wyoming and Mexico. You know, the ones that don’t stand out at all. The ones that look like cool, inviting water.

It looks like they started out with a rainbow scheme, then somehow ran out of colors at level 9, and had to figure out something else to push it out to 15.

And that’s not to mention the unevenness of the color scheme from 0-9. Look at how much the color shifts from 0 to 2 (dark blue to dark green). Now look at how little it shifts from 6 to 8 (medium orange to red orange). The visual shift for each step changes in magnitude.

One Nice Thing: The color scheme from 10 to 15, on the other hand, has some relatively even, yet easy to distinguish, steps.

Thanks, EPA, for helping keep people in the Southwest calm while the ozone layer disintegrates above them.

The Cruelty of War

Another Wikipedia map (don’t worry, they won’t all be from there), showing battles of the American Civil War, based on National Park Service data:

Found at http://en.wikipedia.org/wiki/File:American_Civil_War_Battles_by_Theater,_Year.png, authored by user brian0918.

Amazingly enough, it turns out that the red-coded counties, coded for “Eastern Theater,” are, in fact all in the east! The color coding has no particular use here, except to show you the difference between the NPS-defined theaters of the war. Why not just draw a border around the zones, so that you don’t need a confusing rainbow of colors to tell you roughly nothing that isn’t apparent by looking at where the filled-in counties are?

Also, why is “Mult. Years” the darkest color? This map’s color scheme suggests that “darker is later” – 1863 is darker than 1861. Making a county that saw battles in multiple years (about half of the ones on the map) even darker than the color for 1865 makes it seem like they were fighting the war there well into the 1870s. A media conspiracy has kept it secret.

Quick tip: Let’s say you’re making a map of something that happened, say, 140+ years ago. Using modern county and state borders might be ill-advised.

It looks like the US is tilted backwards. Maybe it’s a commentary by the author – “Look! The US is falling over…a house divided cannot stand!” Actually, what probably happened is they used a sinusoidal projection, which is good for showing the whole world at times, but not so good for showing one country at high latitudes.

One Nice Thing: The color scheme for the years within each theater makes some level of sense – the colors are arranged in a light-to-dark pattern as the years go on. Excepting, of course, the color for “Mult. Years.” Good cartographic sense.