13 maps in 13 days: Damian Spangrud

Sending off the year 2015, we present to our readers the mapmakers who contributed their work to the 2015 GeoHipster calendar.

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Damian Spangrud

Q: Tell us about yourself.

A: I like maps and playing with data (aka analysis). I’m a failed Biologist who became Geographer (CU Boulder, MSU Bozeman) and have been working with GIS for around 25 years now (The last 22 of them at Esri). Over the years I’ve been fortunate to be able to take on a number of ad-hoc mapping, analysis, and visualization projects. These have allowed me to explore creative ideas, some fairly “out there” analysis, and “what if” scenarios of data combinations.

Q: Tell us the story behind your map (what inspired you to make it, what did you learn while making it, or any other aspects of the map or its creation you would like people to know).

A: I experimented with hexagon mapping many years ago, and while it was well established (for 100s of years), I never really saw the attraction of it. I was into modeling and needed to do weighted surfaces and interpolation.

But a few years back I started working on more of the visualization and comprehension aspects of information. Aggregating data (or binning) into well-known shapes is a great approach for providing a higher level view of data. I was CERTAIN that squares (maybe rectangles) were the correct way to do this, but after some experimentation I found that hexagons in many ways worked better, as they don’t impose rigid linear sightlines. And the tessellation of nested hexagons is fascinating in multi-scale maps. (It still pains me to praise hexagons!)

So when the call for maps came out, I was working with hexagons and combined that with my fascination for map projections and showed the nested hexagons across a Goode Homolosine projection. (I also sent one in for another projection (Stereographic) that I thought was better — but the aspect ratio didn’t work for the calendar).

What did I learn? Other than there is a “cult” for Hexagon mapping out there? The nesting hexagons worked great, except that some of the bigger shapes got distorted and didn’t line up quite right. I realized that the hexagon sides with 2 point lines, and when projected they needed to be densified to make the smaller hexagons inside.

Q: Tell us about the tools, data, etc., you used to make the map.

A: Making the map was pretty straightforward. In ArcMap I used a sample script to produce the hexagons at several sizes in *un-projected* WGS 84 coordinate system, and then just played with changing the projection till I had a couple maps I liked.

I went on to document some of this in a blog I wrote in April 2015 — http://blogs.esri.com/esri/esri-insider/2015/04/08/thematic-mapping-with-hexagons/