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

[Russ Garrett]

While looking into this earlier this week, I ended up down a bit of a
rabbit hole. The Forestry Commission has a rather interesting
collection of open data (ODbL-licensed, so compatible with OSM in
theory).

Most relevant to this discussion, they have a map of
"subcompartments", which I think basically equates to landcover -
they're all labeled with type of land use, species, planting date,
etc.

I started looking at this for Kielder, and first impressions are quite
good (these PNGs are all quite large, you might struggle opening them
on mobile):
https://f001.backblazeb2.com/file/russss/kielder-subcompartments-by-date.png

This dataset is last updated in 2019, which is at least roughly
contemporaneous with most of the mapping in OSM, so here are the OSM
woods/forests overlaid on that map:
https://f001.backblazeb2.com/file/russss/kielder-subcompartments-osm-overlay.png

The Forestry Commission's mapping of gaps/cutlines is quite
inconsistent. Some are shown, some aren't. It doesn't seem to be
related to compartment boundaries. It doesn't really match the OSM
boundaries that well in many places either.

But most notably, there are some areas where it's clearly wrong - like here:
https://f001.backblazeb2.com/file/russss/Screenshot-2021-09-03-at-20.15.08.png

That's OSM on top of the Forestry Commission data on top of Bing
there. I'm assuming the Bing imagery dates from after 2019 (copyright
date is 2021 in most places).

The forested area at the top right, which clearly looks like it's
coniferous and planted well before 2019, is mostly marked as "acid
grassland", as are most of the (apparently recently-planted or at
least recently-felled) areas in the middle.

The forested area to the left of the image is marked as "felled" but
the imagery is showing a forest which looks a lot older than 2 years
to me.

Not much of a conclusion here other than "maybe this data isn't as
useful as it looks". It's pretty though.

Cheers,

-- 
Russ Garrett
russ at garrett.co.uk