Wednesday, October 6, 2010

Reading topo maps

If you, or anyone you know, have trouble reading topographic maps, if you just can't make sense of those contour lines and marvel that anyone could read the shape of the land based on all those squiggles -- here's a fine exercise for you.

Check out the New Zealand Topographic Maps, an excellent interface featuring topographic maps overlaid on a Google Maps base. If you select the "Terrain" option, the underlying map will switch to shaded relief, a portrayal that's less precise than contour lines, but gives an easy-to-interpret sense of the shape of the landscape. By moving the slider back and forth, you can adjust the transparency of the overlying topo map and switch seamlessly between the shaded relief and the contour lines. Try it out!

(Also, zoom in on some of those coast lines and note how accurately the topo maps fit with the satellite image. I was impressed.)

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