Monday, November 27, 2017

Map of the Year 2017


The Journal of Maps has named their Best Map of 2017. Their choice for map of the year is a flow map visualization of people moving between U.S. states. The map certainly proved an inspiration to a number of cartographers this year.

Migration in the United States 2009-2013, which we first featured on Maps Mania back in May, uses flow lines to visualize the numbers of people moving between different states in the USA. It includes options to see which states have the biggest exchanges of citizens and to view the most popular state destinations for each individual state.

The US Migration Flow Map is an illustration of a "force-directed method to automatically lay out migration flows". This method has been designed to reduce clutter and improve readability when using flow lines on a map. You can read more about the design principles behind the method in Automated layout of origin–destination flow maps: U.S. county-to-county migration 2009–2013 in the Journal of Maps.


I first stumbled across the US Migration Flow Map in a link in the introduction to Sarah Bellum's Canvas Flowmap Layer. This popular ArcGIS JavaScript API library allows you to map objects flowing from one location to another.

The library uses Bezier curves to visualize the movement of objects on an interactive map. One purpose of using Bezier curves is that you can show the direction of flow by using either a convex or concave curve on your flow line.

The ArcGIS flowmap layer in turn inspired the Leaflet.Canvas-Flowmap-Layer. You can get a great idea of what you can achieve with the Leaflet.Canvas-Flowmap-Layer on this fully adjustable demo map. The map provides a visualization of airport destinations using animated Bezier curves. It includes a number of options which demonstrate the range of animation options provided with the Leaflet flowmap layer.

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