[OSM-talk] Multiple errors in the same location

[Paul Norman]

On 2018-11-21 2:29 PM, Jem wrote:
> > It is a CanVec import from 4 years ago
>
> Is there subtext to this? I saw the weird natural=wood CanVec features 
> yesterday (polys cut up into quadtrees) and wondered about its 
> validity. Is the CanVec import notable for being problematic?

Yes. CanVec is built from multiple sources, so there can be different 
issues in different regions. The issues here with overlapping forest and 
water geometries and overlapping data with existing data are common to 
many CanVec imports. Four years ago is recent enough that the user 
should have known that they needed to fix these problems. Where I live 
there are problems like some data being 40-50 years old.

 From a practical side, when fixing an area, my first step is generally 
to delete any data bears no resemblance to reality. In this case, if I 
wanted to fix just around this lake I would do it by

1. deleting whichever of the water traces is worse;
2. getting any obvious water improvements;
3. deleting the forest inner way; and
4. adding the water as an inner to the forest multipolygon relation.