Inspired by Ben Fry’s All Streets map, which showed every road in the United States, Nelson Minar mapped every river to similar effect. As you’d expect, the geography of the United States emerges without actually mapping locations.
We saw a similar map from National Geographic, which showed the rivers of the world and took home an award for best map of 2010 at Malofiej. So Minar’s map isn’t especially new, but the good bit is that Minar posted a tutorial and his code on github, so that you can see how such a map is made.
Most of the actual cartography is being done in Javascript, in the Leaflet and Polymaps drawing scripts. This tutorial code does very little, mostly just drawing blue lines in varying thicknesses. In addition the Leaflet version has a simple popup when rivers are clicked. With the actual vector geometry and metadata available in Javascript a lot more could be done in the presentation; highlighting rivers, interactive filtering by Strahler number, combination with other vector data sources, etc.
