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.
I was interviewed on the Talking Headways Podcast yesterday. A lot of fun and I even mentioned #emotionalcartographersannonymous, the bad maps I used to make, and some of my favorite maps. Thanks for checking it out!
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.”
Set designer: “Let’s make Beaker’s hair a little more orangish.”
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:
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).
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.
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:
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.
The Guardian made a very difficult but fun quiz out of the City Maps: A Coloring Book for Adults book and published it last week. If you haven’t seen it yet, check it out!
It appears to have had 14,000 shares, 273 comments, and is still trending in their top 10 world, cities, stories list almost a week after publication. Not only that but on a personal note, I think it’s the first internet quiz I’ve gotten 100% correct. I guess I had a slight advantage though.