Azavea Atlas

Maps, geography and the web

You are Invited: Geography Week in Philadelphia

Geography Week

Geography Awareness Week, November 16th-22nd 2014, features activities and events all over the world related to geography and mapping.  Geography Awareness Week was originally established by National Geographic to promote to Geography in American education and to excite people about geography as both a discipline and a part of everyday life.

In Philadelphia, alone, there are numerous events relating to Geography and mapping during this special week.  Below is a round up!

Monday November 17th

Happy Hour Lecture with Carol Collier of the Academy of Natural Science

Tapping Our Watershed, formerly known as the Delaware River Watershed Initiative Seminar Series, will meet next on Monday, Nov. 17, to raise glasses with Carol Collier, the Academy’s senior adviser  for watershed management and policy.

Tuesday November 18th

Esri GeoDev Meetup: Northeast

This event is a social gathering for developers to discuss the latest in mapping, geo technology, geo services, web and mobile mapping apps, app design, cloud solutions, map data or anything else related to solving real-world “geo” problems.  Developers of all levels of expertise are welcome, from seasoned GIS professionals to those new to geospatial development.

Map Measure Manage: How city government uses place-based data for decision making & civic engagement

A showcase of apps developed by or for Philadelphia City government for data-driven decision-support using spatial technology (GIS). See how your city government uses data to make decisions and reach out to citizens.  Find out what data and tools are available to for civic projects.  Drop-in for a Q&A with City staff and see how these tools are helping to improve city services.

Wednesday November 19th

Penn GIS Day

Penn GIS Day, held in conjunction with the National GIS Day celebration, focuses on real-world applications and innovations stemming from uses of Geographic Information Systems. The forum examines the use of GIS both at Penn and more broadly, offering an opportunity for professional and academic interaction.

Thursday November 20th

2014 Geo Open Source Conference Hosted by LocationTech and Geophilly

Philadelphia’s LocationTech event will be a conference-style speaker series featuring technical talks on the convergence of open source and geospatial. A happy hour follows the conference.

Friday November 21st

LocationTech Code Sprint

This event is a code sprint hosted by Azavea. This event provides an opportunity to work on open source geospatial project code with experts. All projects are welcome.

 Sunday November 23rd

250 Miles Crossing Philadelphia – down the rabbithole

A hand, reaching for a gift wrapped in wrinkly tissue paper with an image of the street that lies on the opposite side of the location where this image can be seen – the facade of the Apple Storage Building on 52nd and Willows Avenue. For us this image is the rabbit-hole that leads us into the virtual world in which our project 250 Miles Crossing Philadelphia* takes place. We took the digital Street-view image from that exact location, printed it and made it into this new world again.


Take the opportunity during Geography Awareness Week to attend these events and explore how geography awareness enhances your daily life.

Chart Your Way to Visualization Success

Following up on the themes of Sarah’s earlier blog, “4 Cartography Color Tips Hue Should Know”, here are a few tips I picked up from DataWeek 2014 in San Francisco in September 2014:

Visualizations and infographics are a powerful way to communicate data. However, with great power comes great responsibility, so here are a few ways to make sure they turn out clean, beautiful, and well-suited for their purpose: to be shared with the public.

Use The Cycle of Visual Analysis

Tableau guru Mike Klaczynkski defined the cycle of visual analysis as a six-step process that’s applicable across a broad range of data analysis:

  1. Define the question

  2. Get data to answer the questions

  3. Structure and clean the data

  4. Visualize and explore the data

  5. Develop insights

  6. Share the results

Simple enough, right? The last step, however, is a doozy. If you’ve gone through the trouble of steps 1-5 and then don’t share the results clearly, it could unravel all that hard work. As a data professionals you should provide legible visualizations to share your results with your intended audience.

Check Your Charts Before You Wreck Your Charts

When producing a visualization, do what Dave Fowler from recommends and ask yourself: Am I trying to impress people with how cool this looks? Or am I trying to share my results clearly? If you’re more concerned about bells and whistles on your visualizations, you’ll end up graphics from a 1997 clipart nightmare instead of a powerful way to stream your message. Use the eight steps below and chart a voyage away from the rocky shores of bad decisions:

  1. Make your visualization audience-appropriate. You might not use the same chart to explain something to your dad as you would for your fellow data analysts. You might if he were also a data analyst.

  2. Make a graphic appropriate to the data (e.g. don’t make a time series for something with no time component). This site has a great breakdown on what kinds of charts to use for what kinds of data.

  3. Make sure it’s not a pie chart (people can understand square area better than they can circular areas). Read Death to Pie Charts to learn more and also get a bunch of great visualization tips.

  4. If you’re making a map, make sure it’s not just showing population density, as pointed out in this excellent example from webcomic XKCD (which has been linked before in a previous Atlas Blog about bicycle and pedestrian crashes in Philadelphia by Daniel McGlone). Sometimes you can get around it by normalizing the data by population.

  5. Avoid skeuomorphism in your charts, or trying to make an object look like the thing it represents. While there’s still some debate about whether websites and apps all need be stop being skeuomorphic, but there’s no question that pseudo-3D charts with photos of bananas on them need to go:

  1. Ask yourself if you’re showing the data clearly.

  2. See if someone unfamiliar with the results can interpret it.

  3. Show it off to everyone!

Chart Your Journey to Better Visualization

There are a ton of resources out there to make sure that your visualizations look good and get your message across. Get a head start by checking out the beautiful infographics blog, Information is Beautiful, thumbing through books by legendary visualization experts Edward Tufte or Stephen Few, or trying your hand at a cornucopia of data visualization tools at

Remember, the point of any visualization, whether it’s a chart, graph, or a map, is to communicate data to an audience in a meaningful format.

OpenDataPhilly Launches Visualization Contest is undergoing a redesign thanks in part to grant funding from the Knight Foundation.  In anticipation of the relaunch of Philadelphia’s newly designed data portal, Azavea invites submissions of visualizations of Philadelphia’s open data.

The OpenDataPhilly Visualization Contest calls on designers, data scientists, developers and anyone who enjoys exploring and visualizing open data. You are invited to share your data visualization that utilizes open data found on Your visualization can be static or interactive and may include maps, infographics, charts or any other creative visualization of data.

Visualizations that represent creative and visually impactful uses of Philadelphia’s Open data will be selected to be featured on the new OpenDataPhilly website (to be launched in late 2014).

Up to 10 data visualizations will be selected to be featured on OpenDataPhilly’s new website.  Prizes include $500 in Amazon gift cards to be divided among winners. Additional data visualizations may be selected for display on the OpenDataPhilly web site but only a maximum of 10 will receive prizes.  The contest is international and open to anyone. The data visualization must use open data available on The deadline to submit is Sunday, November 30th 2014 11:59pm.

For more information on the contest or to submit your visualization, please visit:

Join Azavea and The Knight Digital Media Center for a Free Spatial Analysis Webinar

kdmc-logoAttention all nonprofits, foundations, data analysts, and data journalists:

I (Tyler Dahlberg) will be presenting a free webinar in partnership with the Knight Digital Media Center on Tuesday, October 28 at 11am PST/2pm EST. The presentation will be about the origin of spatial analysis, how it works, real-world examples of how it has transformed decision making processes and data display, and how you can get started. To join the free webinar (which is limited to 125 seats) please register for Mapping Insights You Never Knew You Had, which will be administered through the required Fuze web conferencing software.

We hope to see you there!

4 Cartography Color Tips Hue Should Know

Recently attending the NACIS Annual Meeting provided significant inspiration on cartography and visual map design.  This encouraged me to assemble some tips on the thoughtful use of color in cartographic design.

1. Never Use the Default Colors

A frequently mentioned recommendation during the conference was to avoid defaults at all cost.  One specific set of defaults to avoid in mapmaking are the default color schemes (and even classification styles) used for symbolizing data in your maps.  John Nelson made this specific warning during his presentation on 20 Unrequested Map Tips (see tip #3 “Defaults are Evil”).  His map below highlights the worst of the worst of relying on defaults in ArcMap.


Map highlights worst of defaults in ArcMap by John Nelson

Consider using the ColorBrewer web tool (Cynthia Brewer’s collection of beautiful color choices for ramped or categorical  data) as an alternative to Arcmap’s uninspired defaults .  You can even import ColorBrewer schemes directly into ArcMap or other GIS or data analysis software of your choice (GDAL, QGIS, R, TileMill, etc). Happily, a favorite web mapping tool, CartoDB, already includes these lovely schemes.

2. Palette Inspiration

Color selection need not be traditional and stuffy.  Inspire yourself to design a more creative color scheme by browsing some existing color palettes and even create your own. Here are a few I like:




Or browse old maps for inspiration:


Isochronic Distances Map of Travel Time in Days from London, 1914

The above map was used as inspiration for the color palette below


3. Logo or Photo Inspiration

Are you designing a map for a client? Try coordinating their company colors with your map design.  Identify the RBG codes of the colors in a logo or site by using a free eyedropper tool (in your Chrome browser or desktop) or add the Eyedropper tool to your toolbar in ArcMap. Now that you have identified a few of the predominant colors in your logo, decide how they will be used in your cartography (would these colors be suitable for categorical, divergent or sequential data?)  You can simply use these colors for inspiration or you can use a color blender tool like this one or this one to create a range from two colors.  Adjust saturation and transparency to suit your mapped data.  Below is a logo, a ramp and a map created using this method.  I decided to just use a palette made from only the blue in the logo but you can also find a divergent palette using both the red and blue here.

Logo of Inspiration: the Philadelphia Phillies Logo:


A palette created from the primary blue of the logo:


Finally, a map symbolized using the blended color palette:

Find the color palette of the above scheme here.

4. Design for Accessibility

Color deficiency or blindness is an important consideration in cartographic design.  Red to Green color palettes are used frequently when mapping divergent data.  The inability to differentiate these two colors causes significant challenges in interpreting data.  Tip #17 from 20 Unrequested Tips and this fantastic blog post does a great job at describing the shortcomings of some color palettes and makes fantastic (and beautiful) recommendations for accessible colors. When selecting your accessible palette, consult Colorbrewer which has an option to select only colorblind safe palettes.

Other areas of consideration for design accessibility for vision impairment include tactile maps which deserve their own blog post, but I’ll say PATCO’s Tactile Transit Map is worth checking out for inspiration. (Routes and stop amenities are uniquely symbolized using tactile features for easy navigation).


It is important to consider how the colors in your maps communicate and whether it is successful in sharing the correct message.  The book How to Lie with Maps by Mark Monmonier devotes an entire chapter on the misleading use of color in maps.  As a cartographer, you have the power to make creative and thoughtful color choices. Use these tips and guidelines to bring careful color consideration and planning to your maps. This will help you communicate better with a wider audience and help your map stand out in a sea of ArcMap defaults.