Hello, I have completed a first version of a tool to modify elevation data by use of waterbody data from OSM (more precisely currently only the lakes, not the rivers). Description of the process is on [1], the tool on [2].
Primary purpose is better display of lakes in 3d renderings but this can also be useful for relief rendering in 2d maps, i.e. avoiding contours intersecting lakes and for more accurate elevation profiles of routes. The problem is of course that the processing takes some time (Europe at 1 arc second resolution about a night) and changes in the waterbody data would require updates. As a byproduct the process also puts out lists of possible errors in the waterbody data - places where the modification of the elevation model required is so large it cannot be correct. From my first look these have a fairly good signal to noise ratio, i.e. the majority of them are actually errors in the OSM data (a large fraction are shadows in imagery that have been incorrectly interpreted as water like at [3] and [4]). I put up a simple map to look at these for Europe on [5] but you can also find the point list on github. In the long term this is not overly useful as a QA tool without frequent updates of course. Greetings, Christoph [1] http://www.imagico.de/map/dem_water_en.php [2] https://github.com/imagico/dem_water [3] http://tools.geofabrik.de/mc/?lon=23.91222&lat=39.24613&zoom=13&num=2&mt0=mapnik&mt1=bing-satellite [4] http://tools.geofabrik.de/mc/?lon=6.02164&lat=60.45423&zoom=13&num=2&mt0=mapnik&mt1=bing-satellite [5] http://www.imagico.de/map/errormap_en.php -- Christoph Hormann http://www.imagico.de/ _______________________________________________ talk mailing list talk@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk