The Dangers of Hurricane Maps’ Cone of Uncertainty

The New York Times

The cone of uncertainty is a core feature of hurricane maps: it shows the potential routes a hurricane is likely to take (the path grows over time, as we’re less certain where the storm goes next). But it’s misinterpreted in ways that put people at risk. That’s the argument made by Alberto Cairo in an online infographic (and in print) in the New York Times last week: research reveals that people living along the edge of the cone are much less likely to prepare for the storm, even though the edge of the cone is one possible path for the centre of the storm—and the cone only covers 60 to 70 percent of the storm’s potential paths in any event.

Alberto Cairo goes into more detail about the problem, and the responsibility of both journalists and readers when faced with such visualizations, on his blog. His book, How Charts Lie: Getting Smarter About Visual Information, comes out from W. W. Norton next month.

Previously: Rethinking the Cone of Uncertainty.

Alejandro Polanco’s Minimal Geography

Our friend Alejandro Polanco has produced a nifty infographic poster map that is centred, for a change, on the Dymaxion projection. The central map is surrounded by lots of little inset maps and infographics. Called Minimal Geography, it’s available for sale via Kickstarter as a €6 digital download in two print sizes. A second reward level adds a full edition of Alejandro’s Maptorian.

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.

Fewer Maps, But Better Maps

Alan Smith of the Financial Times adds to the conversation about when to use a map to present your data, when not to—he gives an example where a gridded infographic is a much better choice than a map—and when more than one map is required to tell the whole story. “So as lovers of maps, we are keen to create beautiful ones whenever they offer a crucial addition. Truly appreciating them, however, means not defaulting to a map just because you can. Like a lot of things in the world of data visualisation, the right way to use them is to follow the mantra ‘fewer, but better’.” [WMS]

Previously: The End of Maps in Seven ChartsDon’t Make a Map.

Don’t Make a Map

Martin Burch, data developer for the Wall Street Journal, has posted his presentation from the GeoJourNews 2016 conference. Called “Don’t Make a Map,” it explores situations where presenting your data in the form of a map is actually a bad idea, and looks at some better alternatives. “Always make a map,” he concludes, “but don’t always publish it.” Very much in the vein of similar pieces by Darla Cameron (of the Washington Post) and Matthew Ericson (of the New York Times). [Carla Astudillo]

Previously: The End of Maps in Seven Charts.

London’s Population Versus …

london-uk-cities

There’s a certain kind of map found all over the Internet that drives me nuts. It’s the map that compares two geographic regions by labelling one with the other: show that this U.S. state has the same GDP as that country by labelling with that country (or better yet, its flag). But the comparisons can get awfully recondite: labelling the Brazilian state of Rio Grande do Sul with Zimbabwe’s flag because they have similar populations is cute but ultimately useless, unless you have some familiarity with both Rio Grande do Sul and Zimbabwe. They’re bad maps because they’re not really informative—they’re just showing off.

But the problem isn’t necessarily the format. For an exception to the above, see TimeOut London’s maps of London. The first map (above) shows London’s population size by illustrating how many other cities’ populations could be crammed inside London’s boundaries; the same is done with greater metropolitan areas, U.S. cities, Scotland and Wales, and other countries. These maps work because a British-based reader will have some sense of what’s being compared to London: they’re not, in other words, esoteric comparisons. [via]

The End of Maps in Seven Charts

Here’s a short talk from last year by Washington Post graphics editor Darla Cameron, who points out that many maps actually show population density rather than the data they purport to show. “Just because you have geographic data, that doesn’t mean that a map is a best way to tell the story.” She offers some alternative ways to present information—non-cartographic ways—that in some cases do a better job than a map could. (Heretical, I know.) In a similar vein, read the blog post by Matthew Ericson that she refers to at the end of the talk: “When Maps Shouldn’t Be Maps.” [via]