Cartography 101

{Warning: Technical blog post ahead. However, should you choose to proceed, you will be blessed with cartographic enlightenment}

In relation to my job, there are two questions I'm asked on a fairly regular basis. The first is Why do we need cartographers? Haven't all maps already been made? The second is How do you actually make a map?

My answer to the first question is no, not all maps have been made. Data is always changing; for example, think about immigration statistics. Or areas of crime. People are constantly moving. New schools are being built, along with new roads. Or what about election maps on TV every fourth November. Those are never the same as before. Even boundaries change occasionally. Have you visited the new country of Kosovo lately? Or perhaps you've seen the oil maps in relation to the Gulf Coast. No one had mapped those before. So, without going on for several pages, which I easily could, the answer is no. Not all maps have been made.

But, because so many maps have been made before, it does make things easier, which leads me to the second question, How do you actually make a map? First, all cartography today is digital. So when I say draw, it's not with pen and ink. It's with a mouse. And while I have occasionally drawn a map from scratch, like the one seen here, most maps start with a little thing called GIS.

GIS software has revolutionized cartography by making it easy to access data - country boundaries, rivers, roads, cities, etc. And there are people whose boring important job it is to constantly keep this data updated. Some of it's free. Some of it's fairly expensive. But once you have access to it, you can map almost anything your heart desires.

So, to illustrate, let's make a map of DC. Using my handy-dandy software, I can add data. I'll start with adding the boundary of DC. Poof! There it is. That was simple enough.

And then let's get crazy and add lots more. Roads, metro lines, building footprints, parks, water. And voila. We get this messy masterpiece. Remember, the data is out there if you know where to look. For this particular map, I've snatched it off DC's GIS website. They are most kind and give it out for free. Ironically, Knoxville charges a hefty price for the same data. Slick.

Because I don't want to create a map of the entire District, I'm going to adjust my page size and zoom in considerably. I just want to create a map of what's in the frame.

Once I have everything I need, I'll export it out of this program and into another. Illustrator is my personal preference. That's where the magic happens. It gives me complete freedom to place text, change line thicknesses and colors, and jazz things up. I could do this in GIS as well, but it would look like poo.

In all likelihood, I'll probably never finish the map I started above. I have two other maps already in the queu, one of Iraq, plus my first map for NG Magazine, due out in November. But just in case you're curious what a map using the above data might look like, once a true cartographer has gotten their hands on it, then take a looksie at the image below.

This all started as the ugly mess illustrated above. Same info. Same city. This map is from one of my favorite companies, Cartifact. Have you ever seen anything so gorgeous?