Archive for September, 2013

Maps Needed

I’m putting out a general call for map examples to publish in the 2nd edition of GIS Cartoraphy: A Guide to Effective Map Design. All maps will be considered, digital and print. I’m looking for examples of all kinds of maps so submit what you’ve got.

They need to be owned by you or, if not, the copyright permissions must be easily securable in a short timeframe. We aren’t paying money for the maps, for which I am very apologetic, but they will be in a book that was considered a best seller the first time around by it’s publisher so it is likely to gain you some exposure.

These maps are to be featured in the “map examples” section of the book. A short description of each map will be placed beneath it. The maps are not critiqued, just used as examples.

You must be able to supply a high resolution file or screen shot (via quite a large monitor for scaling down). Vertically oriented maps look best as the book is in a vertical format, but I can consider horizontally oriented maps as well.

There’s a “contact” link in the right-hand side bar that you can use to submit. Thank you!

*We’ll be trying to limit the book to one map per author. If you already have a map being published in the book, don’t submit another one.


Digital Map Wrongs and Rights

Murphy’s Law: What can go wrong will go wrong.

Let’s count the ways that your digital map can bite the dust.

1. Labels get cut off at tile seams. (Increase map buffer area.)
2. Effects at land/water boundary don’t work if the two datasets lack topology. Mouths of large rivers and canals? (Use data that was built to work together like Natural Earth.)
3. Layering isn’t correct. Trailhead symbols underneath park shading. (Do lots of testing and moving code and stylesheets around as needed.)
4. Symbols not appearing. (Remember to include them in the right folder and call correctly. Hello.)
5. You forgot to normalize thematic, population-related data. (Normalize.)
6. Line widths aren’t changing incrementally. When you zoom in they just get bigger and bigger until pretty soon the entire map is one road. (Specify a different line-width for every zoom level or groups of 2-3 zoom levels.)
7. Lines are jumbled or too thick at low zooms. (Generalize the low-zoom data. Simplify the lines using a simplifying algorithm.)
8. All features show up but with no styling, all black and Arial and width = 1. (Re-code, nesting isn’t working right.)
9. You published it but nobody cares. (Remove half the functionality and increase the prominence of the central purpose.)
10. You published it and everybody cares but in the wrong way. (Remember the most vocal voices are not always the majority opinion.)

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Dale Chihuly Can Really Make a Mess

******Note: From time to time old posts are resurfaced. This post is from June 20, 2011. The New York Times just published a piece called It’s Not ‘Mess.’ It’s Creativity on September 13, 2013, where it’s argued that a messier work environment begets more innovative and creative work.*********

For many artists, the ability to work without constraints is necessary for the creative process. One of the things that often holds people back is their inability to make a mess. Maybe those childhood memories of parents being upset by a spilled glass of milk or a messy room manifest into a perfectionist attitude that impedes artistic disarray in adulthood. However, if you can overcome that and allow yourself to use trial and error, make mistakes, and create disorder, the end result can be a freeing of the mind and a corresponding heightening of creativity.

Take Dale Chihuly, the famous glassblower who injected the world of glass art with dramatic pieces, humongous installations, and massive doses of color. Ever since a dislocated shoulder prevented him from directly working the glass, he has communicated his visions to his team via paintings. And it is in a picture of him working on some paintings that you’ll see the messiness connection come in:

The ability to make a mess in order to create a higher level of finished product is great. The lesson for those in the map-making profession is that it is okay to start off a project however it works best for you.

Maybe you need to throw a lot of elements on to the page and move them around until you get the right look. Maybe you need to sketch out your vision on paper before using the computer. Maybe you need to make a painting that gets at the essence of the finished map you desire. Who knows, with this kind of up-front creative work maybe you’ll make as large a difference in the cartography world as Chihuly has made in the art world.

****Another update: this just out from xkcd :) *********



It’s been quiet on the blog this week as it’s nose-to-the-grindstone here, and for the next 5 weeks. I’m putting the finishing touches on the manuscript for the 2nd edition of GIS Cartography: A Guide to Effective Map Design. Not the finishing, finishing, finishing touches yet. Just the first stage of the finishing touches. Anyone who’s ever authored anything, you know what I mean.

We’re thinking about changing the title to “Geospatial Cartography: A Guide to Effective Map Design”. Better, but long.

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Thanks Go Out To The Emergency Mappers, Colorado Flooding

A shout-out to our mapping colleagues doing great work to support the emergency efforts during the Front Range (Fort Collins, Boulder, Lafayette, Greeley, Longmont, Loveland, Johnstown, etc.) flooding and keeping us updated with their tweets. This isn’t everyone, I’m sure, so let me know who I’ve missed and I’ll add to the list.

Jacob Mundt, GIS Coordinator, Weld County
Jill M Terlaak, GIS Coordinator, City of Greeley
Brian Sullivan, Municipal GIS Manager, City of Greeley
Brendan Heberton,
Royce Simpson, GIS Application Developer, Larimer County
Kelly (@GreeleyGeek)
David H (@dvdhns)
Rich Ruh (@RichRuh)
Brian Sullivan (@Taliesn)

Colorado Flood Threat Portal
2013 Boulder Floods Crisis Map
Boulder County Road Closures
Jefferson County Flood Map
Three Day Rainfall Totals

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Zoom Levels, Pixel Sizes, and Scales, Oh My

Ever wondered what the map scale is at each zoom level in a digital map? Well, it’s not an easy answer, since almost all webmaps are in the Web Mercator projection (some are in Web Mercator Auxiliary Sphere), which has a greatly varying scale depending on your latitude.

The varying scales of a Mercator projection:

Assuming a 96 DPI*, we can translate the zoom levels to map scales and pixel sizes, and for the sake of simplicity they have been recorded only for locations at the equator. Here’s the very useful Esri chart for this. Obviously these will change depending on how far from the equator your features are. But it is a good start to get a handle on, say, what datasets will look good at what zoom levels. For example, you might want to use some Natural Earth large scale data that comes in 1:10m resolution. You’ll see from the chart that it will look good through zoom 6.

The Esri chart is, like I said before, quite handy. However, you might want to see just approximate scale equivalents as you go about looking at various datasets and plotting which ones are good at which zoom levels. Incidentally, if you’re doing an exercise like that, I highly recommend making a data chart in a spreadsheet and putting these values across the top, horizontally, and then xing out or coloring the squares that correspond to each dataset’s resolution. This gives a handy visual way to scroll through 100+ datasets to see what resolution they have.

REMEMBER these are just APPROXIMATE scales for each zoom level. Not only does it vary by latitude but these have been significantly rounded:

zoom approx. scale
0 1:500m
1 1:250m
2 1:150m
3 1:70m
4 1:35m
5 1:15m
6 1:10m
7 1:4m
8 1:2m
9 1:1m
10 1:500,000
11 1:250,000
12 1:150,000
13 1:70,000
14 1:35,000
15 1:15,000
16 1:8,000
17 1:4,000
18 1:2,000
19 1:1,000

You’ll note that in the Esri zoom level document they also wrote out how many meters, at the equator, one pixel is. Why would this be at all important? Simply put, if your features are less than one pixel in size, this may have implications for how much of that data you show and how you style it. For more on that and some other very interesting dot styling information, see Eric Fischer’s excellently illustrated Mapping Millions of Dots article.

*See this post on why I/we/everyone shouldn’t be assuming 96 dpi. Required reading!