[OSM-talk] Fixing broken multipolygons, some notes

[Christoph Hormann]

On Sunday 19 March 2017, Andreas Vilén wrote:
>
> Also, as has been pointed out earlier, Corine data might be bad, but
> does not contain that many pure data errors as we define them.

That is not quite accurate in my experience.  As i explained in

https://lists.openstreetmap.org/pipermail/talk/2017-February/077553.html

landcover mappings like corine are based on selecting the least unlikely 
of a fixed set of landcover classes at a certain scale based on certain 
criteria and reference areas and this frequently produces completely 
bogus results.

In areas like here:

http://www.openstreetmap.org/#map=13/56.7935/16.0168
http://www.openstreetmap.org/#map=13/62.7015/25.6678

the Corine based landcover data in my eyes has not connection to reality 
at all, it is factually simply wrong.

I understand that the perspective to loose all the data and to be 
without any forest mapping until manual mapping has filled the gaps 
seems not so pleasant but i am pretty sure there are a lot of people 
from abroad who would be glad to help you with either manual forest 
mapping or importing better quality data in a way that is better 
maintainable and more compatible with manual mapping activity.

However as long as the bad quality Corine data is there and meant to 
stay few people are interested in editing this mostly meaningless data.

-- 
Christoph Hormann
http://www.imagico.de/