Lars Ahlzen worked up a beautiful online topographic map of the entire state of Massachusetts using data from OpenStreetMap and MassGIS, and only free and Open Source tools. Lars is a software developer for a Boston online retailer who has attended a few OpenStreetMap mapping parties, but has no formal training in GIS or cartography.
I found the beauty of his work inspiring, so I tracked him down and we spoke on the phone. He was motivated by his love of maps, and the fact that all the data needed to create a detailed topo map of the entire state were available, but nobody had done it.
Using the topographic maps of the National Geographic Society as motivation and inspiration, Lars loaded the OpenStreetMap data into a PostgreSQL database and downloaded other data layers, such as hydrography, contours and hill shading from MassGIS. This data was then reprojected to the OSM projection. He used Mapnik, GDAL, ImageMagick and other free software to render the tiles that make up the map, writing a number of custom scripts. Custom styles were then created in Mapnik, with a good deal of tweaking to get the look he was after. Finally, he left one of his workstations running for a few days to do the rendering.
Lars is from Sweden, and has lived in the United States for four years. He commented that all the mapping data is closed in Sweden, so he couldn’t have done anything like this in his home country. But he did say that a lot of good work is being done in Sweden through OpenStreetMap.
He indicated that the map is a work in progress, with plans to add add a more detailed description of the process on the toposm.com site soon, including the scripts and styles so that others can replicate and add to his work for other geographies.
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Very nice map. I did notice that Fall River looks to be as populous as Boston while larger places like Springfield &/or New Bedford appear as villages.
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