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<div class="moz-cite-prefix">On 15/09/2021 21:30, Tom Crocker wrote:<br>
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<blockquote type="cite"
cite="mid:CAHmUbmdFcdQprHa0AMENL6h+RbsOCifXm6mYrHPBY3_9bmfd+A@mail.gmail.com">
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<div dir="auto">I was wondering if anyone has summarised how to
distinguish grassland, heath, scrub and wood and the common
plants or features in Britain that help define these for the
non-botanist like me. <br>
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<p>As you say, there's seldom a single factor which makes a tag
obvious, however personally, a few factors help:</p>
<ul>
<li>landuse=meadow often has beasts grazing, small sheds
(building=stable), even quality grass, no signs of regular
cultivation (e.g. tractor tracks) EXCEPT where it has been cut
for silage. The surface can seem 'rough' in oblique light due to
a mix of wild plants. Meadow is often in lower altitude areas,
and close to landuse=farmyard (easier to tend the beasts). You
can often see the tracks used twice daily to check the stock.<br>
<br>
</li>
<li>landuse=farmland might not be green (time of year?) and
regularly has tell-tale tractor tracks showing cultivation. Some
crops appear like green grass, others are green but 'very rough'
- guess at brassicas?<br>
<br>
</li>
<li>natural=scrub has small bushes, trees, etc. Not enough to be
natural=wood, not mechanically planted in lines for
landuse=forest. Sometimes useful for field margins, or what
could be set-aside left to grow naturally.<br>
<br>
</li>
<li>natural=heath is usually at higher altitudes where the soil
isn't good enough for meadow or farmland and population density
is very low. The hard judgement is when to tag meadow/heath. The
high altitude areas are easier - few fences/dry stone walls, the
odd sheepfold, large open areas with peaks. Gorse can appear as
spiky bushes and does flower yellow for a few months. <br>
As the land rises and conditions worsen, the probability of
heath increases in my mind. Does the open area seem cultivated?
Does it have signs of improvement like land drain marks (also
installed as prep for landuse=forest though)?<br>
You might see heath being improved into forest, perhaps where an
estate has investment from wind farms (land drains, enclosure
fences, machine planting lines).<br>
</li>
</ul>
<p>Over a county area, it is often possible to see the topography
from landuse - farmland -> meadow -> forest / heath as the
conditions change by height.</p>
<p>On a field area, unless you're supplementing with ground truth,
species is unlikely to be accurate - and crop rotation may well
change meadow/ farmland/ forest next year.</p>
<p><br>
</p>
<p>Oh, and building a very recent top tip for JOSM users Tom was
kind enough to pass on last week:</p>
<ul>
<li>Install the ShrinkWrap JOSM plug-in <a
class="moz-txt-link-freetext"
href="https://github.com/ubipo/shrinkwrap">https://github.com/ubipo/shrinkwrap</a></li>
<li>map the field boundaries, gates, forest areas over an large
area creating enclosed land parcels</li>
<li>(have a quick check with the cadastral layer for imagery
alignment)</li>
<li>Add-in untagged temporary lines to close fence gaps - leave
untagged so validation will pick them up if not deleted.<br>
</li>
<li>Point at the middle of a field area, double check it is
enclosed, Shift-Alt-B, Shift-Ctrl-V and the field is mapped.</li>
<li>Just remember to check for gaps - the balloon tool can
disappear like the escaping sea for 15minutes if you don't!</li>
<li>Add tracks (grade2 grade5?), power=minor_line, etc last to not
confuse the balloon tool<br>
(otherwise fix validation "Way contains segment twice" Errors
with P to chop off the way surrounding the track).<br>
</li>
</ul>
<p>A chunk of the Scottish Borders N of Berwick Upon Tweed has
enhanced detail with individual field-by field landcover using the
balloon tool this week. With practice, it works well.</p>
<p>Happy Mapping,<br>
</p>
<p><br>
</p>
<pre class="moz-signature" cols="72">James
--
James Derrick
<a class="moz-txt-link-abbreviated" href="mailto:lists@jamesderrick.org">lists@jamesderrick.org</a>, Cramlington, England
I wouldn't be a volunteer if you paid me...
<a class="moz-txt-link-freetext" href="https://www.openstreetmap.org/user/James%20Derrick">https://www.openstreetmap.org/user/James%20Derrick</a>
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