[Imports] Announcement: Corine 2006 Land Cover Import for Republic of Ireland

[Dermot McNally]

On 17 January 2011 17:13, Andy Allan <gravitystorm at gmail.com> wrote:
> On Mon, Jan 17, 2011 at 5:00 PM, Jaak Laineste <jaak at nutiteq.com> wrote:
>
>>  I would suggest to create regional .osm files (for counties or municipalities) for forests and other more interesting themes, but just share them for handpicking specific polygons (copy-paste in JOSM), do not import them automatically.
>
> Potlatch2 also supports hand-picking from "Vector Background" layers -
> allowing you to treat something like Corine as just another background
> but bypassing tedious tracing. I think moving away from bulk-imports
> and improving the editing apps to work better with these shared vector
> sources is the best way forward.

I get what both of you are saying, but:

The fact is that we've had the ability to trace landsat for ages now,
Yahoo in places and Bing now in a bunch more areas. It isn't giving us
full land cover information is isn't likely to any time soon, if ever.
Part of this is the fact that mappers map partly what they realise
they can map. I know that there are cases where imports have removed
the motivation of mappers to participate. I don't see that danger
here.

Basically, having reviewed the quality of the Corine data for Ireland,
I have come to the following conclusions:

* It's not perfect, but...

* ...It's a lot better than the _nothing_ we currently have in a lot
of the country

* It's too much and too details for a small community to be motivated
to manually trace

* It includes stuff that's quite hard for a lay mapper to identify by
other means (peat bogs, different types of agriculture, categories of
tree in forests)

* Even though the Corine lakes may be crude, they are often better
aligned than the stuff traced off uncalibrated landsat.


My conclusion (and one shared by the main mappers here) is that we
would rather tweak the Corine stuff (and do some de-duplication) than
have to work from scratch. But it is certainly our challenge to make
sure that, if we go ahead with this, we leave the map better than we
found it. Others may feel that no landuse is better than crude stuff -
I respect that view, but not as much as I respect people who believe
that strongly enough to come over here and map it all properly ;)

This is also announced on the Irish mailing list. Let's see what
concerns are raised there. I'm not afraid of putting imperfect stuff
on the map, but I am afraid of discouraging future improvement of it
once it's there. That needs to be a key go/no-go criterion for us.

Thank you all for the feedback (and no doubt there will be more),
Dermot

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