Cartographer's Toolkit

Map Making Tips, Tricks, and Inspiration

Hang tight

July 9th, 2016

*Update* The revision went live in all outlets the week of July 11, 2016!

I’m working furiously on a completely revised and updated version of City Maps: A Coloring Book for Adults

cattype

On the importance of rapid information transmittal

June 30th, 2016

While reading this news piece on bitcoin this morning I came across this chart:

Just the top portion of the chart

Just the top portion of the chart

Since this was some quick pre-work reading on a subject I follow from time to time but don’t study in-depth, I spent only about 5 seconds looking at the chart before I determined that it would be too much effort to understand. I thought to myself, “I know this chart is probably revealing some amazing truths and is well-done, because I trust the New York Times Graphics Department, but I’m not going to take the time to understand it this morning.”

This was a huge reminder to myself that this is precisely the way that 99% of map readers react to complex maps that they see. The lesson? If you want the majority of the readers to understand something at a glance, keep it as close to a normal, popularly familiar, map style as possible. But, you say that you are a leader in the cartography field who’s job it is to come up with fancy new visualizations?

While it may be true that only the lead dog sees the landscape (hat tip Alan Weiss), the lead dog has to navigate and interpret that landscape for its pack. Likewise, a cartography leader needs to make sure that his/her followers understand the map quickly and clearly.

Here’s a map-based example. I think that the map shown here is a little too strange to invite a quick interpretation for the reader overall. Furthermore, the legend info pertaining to the colors is actually found in the article text whereas it would have been nice to have it also accompanying the map:

Tax map

Tax map

 

(Please note: I never want to discourage innovation nor do I ever want to discourage individuals from publishing for fear of getting critiques like this. While I am critiquing the amount of time it takes to interpret this map I do like the varying transparency, the subtle background color, the thin white lines to unobtrusively denote county boundaries, and the use of orange as a counterpoint to the blue. There are many successful things about the map and I always think to myself that it could just be me having trouble with the other bits and that there’s a possibility everyone else completely understands this thing at a moment’s glance. TLDR: this is just one persons opinion and likely to be wrong.)

So what do you do if you still want to use one or many innovative visualization techniques in your cartography?

Answer 1: That’s perfectly okay if the map can be interpreted very quickly despite the fact that it looks different than what we’re used to. Hint.fm/wind comes to mind as an excellent example of a new technique that was actually easier to understand than any prior techniques for showing wind.

Answer 2: Leave the more complex cartographic innovation for media that invites longer perusal such as, but not by any means limited to:

  • Map focused books
  • The Sunday magazine instead of the regular paper
  • Scholarly articles
  • Twitter map nerd feeds
  • Advanced conference tracks
  • Github repositories
  • Educational tutorials

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Books at the EsriUC Store

June 27th, 2016

As most geogeeks are aware, the Esri UC is happening this week. I’m not there this year but thankfully someone has already sent me a pic of City Maps on the shelves at the Esri UC Store at the conference. So nice to see! Even if it is right next to some gagged guy underneath a horse. :)

 

Two of my other books are reportedly on sale there as well. I’ll post any other pics of the books at the Esri UC here if anyone cares to send them. :)

Edited 6/27/2016 to add: I heard that City Maps is now sold out at the EsriUC Store. I haven’t heard if Cartographer’s Toolkit or GIS Cartography are sold out or not.

Edited 6/29/2016 to add another pic I somehow missed from a few days ago:

Edited 6/29/2016 12:07pm MT:

Edited 6/30/2016 to add:

Color Critique Will Always Be There For You

June 23rd, 2016

A client warned me the other day: “I like the color schemes but just so you know these bosses have a way of changing colors, it’s the way we work around here.”

I said, “Right, that’s completely expected but thank you for the heads-up because it means that I will take a few minutes of extra time at our next demo to explain that these colors come from a previously published paper on the subject. That way if they do decide that the palette should be changed, they’ll be aware that it will be different from the published standard.”

I added, “Having been in the cartography business for 17 years, I’ve learned that debate over color is part of the career. Sometimes even for the better.”

beaker

Set designer: “Let’s make Beaker’s hair a little more orangish.”


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Creating an Aspect-slope Map in GeoServer

June 22nd, 2016

An aspect-slope map (sometimes called a slope-aspect map) is an overlay of a semi-transparent slope map on top of an aspect map that is styled with a unique hue for every 45 degrees of slope direction. To put it visually:

aspect_slope_visual

To do this in GeoServer, you need slope and aspect raster datasets in degrees. Create an SLD for each with the following syntax (I’m not including the whole SLDs here for brevity).

SLOPE SLD

<sld:ColorMapEntry color=”#999999″ opacity=”1″ quantity=”10″/>
<sld:ColorMapEntry color=”#999999″ opacity=”.66″ quantity=”20″/>
<sld:ColorMapEntry color=”#999999″ opacity=”.33″ quantity=”30″/>
<sld:ColorMapEntry color=”#999999″ opacity=”0″ quantity=”90″/>

Here we have a gray color being used to denote very flat areas where the slope is less than 10. The gray is increasingly transparent as the slope becomes steeper, thus revealing the underlying aspect layer with more brightness in the steepest locations. These parameters could be tweaked to allow more or less brightness to show through.

ASPECT SLD

<ColorMapEntry color=”#9AFB0C” quantity=”22.5″ />
<ColorMapEntry color=”#00AD43″ quantity=”67.5″ />
<ColorMapEntry color=”#0068C0″ quantity=”112.5″ />
<ColorMapEntry color=”#6C00A3″ quantity=”157.5″ />
<ColorMapEntry color=”#CA009C” quantity=”202.5″ />
<ColorMapEntry color=”#FF5568″ quantity=”247.5″ />
<ColorMapEntry color=”#FFAB47″ quantity=”292.5″ />
<ColorMapEntry color=”#F4FA00″ quantity=”337.5″ />
<ColorMapEntry color=”#9AFB0C” quantity=”360″ />

The colors and class breaks are from this Esri/Buckley blog entry which, in turn, references the color scheme from Moellering and Kimerling’s MKS-ASPECT (GIS world 1991). The colors, in order, are shown here:

 

aspect_slope_palette

PUTTING THE LAYERS TOGETHER

Using a two-layer syntax in the wms request mashes the two layers together. List the aspect layer first and the slope second. I had it switched around on my first try and it took me a bit of time to realize that it draws that second referenced layer on top. And no, the finished map does not have a hillshade underneath. The combination of aspect and slope creates that “hillshade” effect.

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Cartographer's Toolkit

Map Making Tips, Tricks, and Inspiration