Diagrams of Power

Diagrams of Power, a group exhibition taking place right now at OCAD University’s Onsite Gallery in Toronto, “showcases art and design works using data, diagrams, maps and visualizations as ways of challenging dominant narratives and supporting the resilience of marginalized communities.” Curated by Patricio Dávila, it runs until 29 September. Free admission.

Update: The above is lacking in some detail; here’s the Toronto Star review to make up for it.

Advice on Choropleth Maps

Last month Lisa Charlotte Rost published a post on Datawrapper’s blog full of tips about choropleth maps: when to use them (and when not to), how to make them better (lots about colour use), along with some examples of good ones. Worth bookmarking.

She followed that up with another post focusing on one particular factor: the size of the geographic unit. Choropleth maps that shows data by municipality, county, region, state or country will look quite different, even if they show the same data. Averages tend to cancel out extremes. She gives the following examples:

Comparing Cartograms


Datawrapper has added population cartograms to its map collections, and in its blog post discusses the advantages and disadvantages of cartograms vs. geographical maps, as well as the advantages and disadvantages of some of the different types of cartograms. Turns out that cartograms are kind of like map projections: each has its pros and cons; each is better suited to some uses than to others. [Caitlin Dempsey]

Snowfall as Animated Relief Map

Here’s something neat from Garrett Dash Nelson: “the total seasonal snowfall in the continental US for 2017–2018 so far, shown as a relief map,” where total snowfall is expressed as elevation. That’s neat. Even neater: the animated gif that depicts it (a frame of which is above). Even neater than that: he shows how he made said animated gif.

Examples of Multivariate Maps

Jim Vallandingham looks at multivariate maps:

There are many types of maps that are used to display data. Choropleths and Cartograms provide two great examples. I gave a talk, long long ago, about some of these map varieties.

Most of these more common map types focus on a particular variable that is displayed. But what if you have multiple variables that you would like to present on a map at the same time?

Here is my attempt to collect examples of multivariate maps I’ve found and organize them into a loose categorization. Follow along, or dive into the references, to spur on your own investigations and inspirations!

Jim’s examples of maps that display more than one variable include 3D maps, multicolour choropleth maps, multiple small maps, and embedded charts and symbols. Useful and enlightening.

Ingo Günther’s World Processor Project

Ingo Günther’s World Processor project, which projects historical, political, social and environmental data visualizations onto literally hundreds of illuminated globes, gets a writeup in, of all places, Bloomberg’s Pursuits section, which treats his globes as a luxury good: “as much fine-art object as C-suite accoutrement.” This seems rather beside Günther’s point, in spectacularly late-capitalist fashion. [The Map as Art]

I first told you about Günther’s work in 2005. Here’s his home page, and an exhibit at the Bryce Wolkowitz Gallery.


Will Geary’s TransitFlow project is an experimental set of tools to build animated transit flow visualizations, built from Transitland’s open-source transit schedule data. More than a dozen visualizations are available in video form here; each shows the flow of trains, buses and other forms of transport over the course of a day. Very high visual appeal. More at the Guardian. [Metrocosm]

National Geographic Infographics

ng-infographicsSpeaking of National Geographic. If the magazine is known for its cartography and its photography, one should not forget the illustrations, charts and infographics that accompany many of the articles and appear on the back of every folded map that comes several times a year with a magazine subscription. Now there’s a book of them: National Geographic Infographics. Edited by Julius Wiedemann and published by Taschen, the book “gather[s] the magazine’s best infographics of the past 128 years.” More at Atlas Obscura and Wired.

A Map of Global Shipping

This interactive map shows the location of every single cargo ship over the course of 2012. Shipping routes (the Straits of Malacca look particularly bottlenecked) and materials shipped are available via the interface, and there’s a nice narrated tutorial explaining how the map works. Thanks to David Krathwohl for the tip. [Digg]

Previously: Live Marine Traffic MapsESA Maps European Shipping Routes.

Indian Railways Reachability Map


Sajjad Anwar and Sanjay Bhangar have been playing with train, station and schedule data from Indian Railways, one result of which (so far) is this reachability map—all the destinations reachable by a single train (i.e., without a transfer) from a given station. [Sajjad Anwar]

Previously: A Map of India’s Railway Network.

The Ordnance Survey Maps Britain’s Favourite Routes


The Ordnance Survey has created a series of data visualizations showing the most popular walking and cycling routes, based on OS Maps usage. “The 500,000 plus routes were illustrated in a series of beautiful data visualisations by [cartographic designer] Charley [Glynn], who found it amazing that the people who created routes for their outdoors adventures had logged almost every bit of British coastline. It neatly frames the rest of the data and gives the illusion you are looking at a map of Great Britain. The darker, thicker areas illustrate the higher concentration of routes and reveal popularity.” Flickr gallery. [Mountain Bike Rider]

Average House Prices in the U.K.

British housing market analyst Neal Hudson posted a map of 2015 average house prices in the U.K. to Twitter last week. London is unsurprisingly dire.

[Maps on the Web]