[OSM-talk] Argh, Canvec imports

[Frank Steggink]

Quoting Michal Migurski <mike at stamen.com>:

> A cry of frustration:
>
> I do bimonthly runs of the worldwide coastlines   
> (http://metro.teczno.com/#coastline), and Canada seems to be a   
> recurring source of problems. What the heck is going on up there? I   
> consistently see new imports of what seems to be Canvec data   
> screwing up coastlines and making for some deeply broken renders:
>
> 	http://mike.teczno.com/img/broken-coast.png
>
> Most of that junk in the Atlantic Ocean is newly introduced within   
> the last few weeks, and is making it difficult to get out a clean   
> coastline suitable for rendering. It shows up in the main OSM mapnik  
>  tiles in Hudson Bay, too:
>
> 	http://www.openstreetmap.org/?lat=55.7&lon=-83.6&zoom=5&layers=M
>
> I've been trying to fix problems as I encounter them and I've   
> managed to fix invalid coastilnes around Baltimore, Houston, Tampa   
> and the dreaded Montréal area in an effort to generate a usable map   
> of North America, but this Canvec stuff is absolutely killing me.
>
> -mike.
>
> ----------------------------------------------------------------
> michal migurski- mike at stamen.com
>                  415.558.1610
>
>
>
>
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Hi Michal,

The rendering error northeast of Quebec City was caused by a novice  
user who has adjusted the Canvec data which was already there. The  
import in this region was done by me about half a year ago.

The user in question had adjusted the coastline tags to  
waterway=riverbank, in order for him to show it up properly on his GPS  
(while using mkgmap for the conversion). He already became aware of  
what he has done, and has fixed the error himself (which I think is  
laudable). I've done a check, and the coastline looks all right to me.  
I'm not sure what to do with the remaining waterway=riverbank tag.  
This is part of a larger discussion about what to do with large  
waterbodies.

The slippy map doesn't show the corrected situation yet, because the  
coastline shapefile is not updated very often.

Regards,

Frank