[Talk-GB] Mapping of Kielder Forest(s)

Russ Garrett russ at garrett.co.uk
Mon Aug 30 18:59:49 UTC 2021


Hi James,

First off I would like to emphasise that I am not suggesting the
removal of any detail here.

I am suggesting that small gaps in the forest should not be
represented by gaps in the forest polygons, but should be replaced
with man_made=cutline (and/or a highway tag), which would reduce the
number of individual landuse polygons. Larger gaps (such as the old
farmsteads, etc) should certainly be preserved, potentially as holes
in a multipolygon.

On Sun, 29 Aug 2021 at 19:53, James Derrick <lists at jamesderrick.org> wrote:
> This detail was added to give information to walkers and riders (horse/
> pony/ fit mountain bikers) where access may be easier - walking along a
> forestry haul road is easy; across the ridges created by a commercial
> planting machine is very hard.

Ideally in OSM this should be communicated via highway ways - probably
by highway=track - and this would allow additional useful info on
surface quality to be added. The gaps between landuse polygons are not
necessarily indicative of a passable route in OSM (although they are
in OS StreetView). I've visited Kielder Forest several times so I
appreciate that a lot of these gaps may not be passable by vehicle or
even on foot.

> I can see that adding a master relation to bring individual stands of
> landuse=forest trees together could be useful, however where do you
> start and stop?
>
> The Forestry Commission signage on the ground suggests they manage the
> wider landscape with areas / plantations / species collectively known by
> several names, not just Kielder.
>
> Do you have access to this level of hierarchical data (I don't even with
> ground survey, beyond specific areas - e.g. Hawkhirst, Bakefin) or are
> you suggesting one level of "Kielder"?

I was trying to avoid this discussion, which I think is a separate
issue, but I will summarise it briefly: Forestry England does
designate these as 13 separate forests (all of which are considered
part of Kielder Forest), and they have a rather interesting set of
plans available on their website:

https://www.forestryengland.uk/forest-planning/kielder-forest-plans

Unfortunately these plans appear to be encumbered by OS copyright, so
we can't use them in OSM. (There is quite a lot of open-licensed
Forestry England data, but seemingly not anything with the actual
names of the forests.)

I'm not suggesting that the entire area should be tagged as "Kielder
Forest". To start with, I was planning to roughly group these based on
the naming visible on OS StreetView. The way OS names the forests
appears to be slightly different from the way that Forestry England
names them - Forestry England has names for various sections of forest
around Kielder Water which OS just calls "Kielder Forest" - but I
think this might align better to how they're interpreted on the ground
anyway.

At any rate, these areas aren't really named in any sensible way at
the moment. My primary intention with this was to try and make sure
they are. This can always be tweaked later.

> My general approach is to map from imagery, but do recognise from my own
> walks on the ground that areas may be clear felled and appear barren.
> These typically are replanted relatively quickly (in the 10-20 year
> lifetime of a softwood tree) and rarely change use (e.g. continued
> forest, not meadow) due to the physical geography (terrain, altitude,
> thin rocky soils).
>
> By breaking the overall forest into individual stands of landuse=forest,
> it seems relatively simple to change the status of one area as it changes.

I don't think it's particularly realistic to try and keep up with the
state of each individual part of the forest. If this was the case then
it could potentially be worth keeping it mapped at a more granular
scale, but I think this is a losing battle. From what I've seen so
far, a lot of what is mapped in OSM is already out of date compared to
the newest Bing imagery.

Personally think that it's fine to keep even a recently-felled area
tagged as "forest". It will be re-planted soon enough, and may even
already have been if you're operating off aerial imagery.

Cheers,

--
Russ Garrett
russ at garrett.co.uk



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