Change
Register
The
Welsh Highlands - Uchafion Cymru
490m
Subs
All
hills in Wales at or above 500m in height with a minimum prominence of 15m;
from the 500.5m summit of Moel Bowydd to the 1084.8m summit of Yr Wyddfa
On the 7th January 2023 it was announced that the 490m subs have been dispensed with, therefore the Change Registers for these are now redundant. However, they will remain on Mapping Mountains as a historical documentation of this list, although their totals will no longer be used.
‘The Welsh Highlands - Uchafion Cymru’ is a hill list co-authored by Myrddyn
Phillips and Aled Williams, and was first announced on the Mapping Mountains
site on 4th November 2015 where a complete breakdown of hill totals
was listed by Group. The list then
comprised of 630 hills within the main list that met the qualifying criteria
with over 100 of these hills making their first known appearance in any form of
hill list; emphasising the fact that this listing is the most comprehensive of
its kind for this height band of hill in Wales.
The listing originated in 2004 at which time it included a sub category for those hills that met the qualifying height but only had 14m or more and below 15m of drop, these are now known as the Welsh Highland Subs and as of the 7th January 2023 been revised with their criteria being all Welsh hills at and above 500m in height with 10m or more and below 15m of drop. This listing now includes two other sub categories; the 490m Subs and the Double Subs and this Change Register details those hills that are, or have been listed within the 490m Subs category.
The 490m Subs are
those hills that fail to meet the Welsh Highlands - Uchafion Cymru qualification by 10m or less of height, these are the hills that
are 490m or more and below 500m in height that have a minimum 15m of drop.
Since ‘The Welsh Highlands - Uchafion Cymru’ listing originated it has
developed ever since with it now being co-authored with Aled Williams, having the
two other sub categories within it, and having over 330 marginal hills surveyed
using a basic levelling technique. It is
now also benefiting from the accurate surveys conducted with GPS / GNSS
receiver, an expanded range of Ordnance Survey maps available online and most
recently, by analysis of LIDAR data.
However, it is not just numerical data that has seen this list develop since its first inception, it is also place-name data, and it was because of this and their mutual interest in hill lists that the authors first corresponded.
However, it is not just numerical data that has seen this list develop since its first inception, it is also place-name data, and it was because of this and their mutual interest in hill lists that the authors first corresponded.
In recent years, acronyms or short monikers referring to
specific hill lists have become increasingly popular in hill-walking circles,
and during the compilation of this list which used to be referred to as the ‘The Welsh
500m P15s’ the authors have used the Welsh word ‘Uchaf (Higher)’ to refer
to these hills, with the plural being ‘Uchafion’, since these summits take in
the higher tier of the Welsh uplands. For the time being this moniker will be used on the Mapping Mountains site to refer to this class of hill.
It seems fitting that the list of ‘The Welsh Highlands - Uchafion Cymru – 490m Subs’
should now benefit from a detailed Change Register, and although the hill
list in its entirety is not yet published it is prudent for this Change
Register to initially detail the changes to this sub category since the
November 2015 introduction published on the Mapping Mountains site.
The Change Register to ‘The
Welsh Highlands - Uchafion Cymru – 490m Subs’ appears
below with the reclassifications to the 490m
Subs list being detailed chronologically in receding order.
Change
Register
The
Welsh Highlands - Uchafion Cymru – 490m Subs
On the 7th January 2023 it was announced that the
490m subs have been dispensed with, therefore the Change Registers for these
are now redundant. However, they will remain on Mapping Mountains as
a historical documentation of this list, although their totals will no longer
be used.
Cwar Blaen Dyffryn 496.0m at SO 09829 14840
 |
| LIDAR image of Cwar Blaen Dyffryn (SO 098 148) |
This hill’s addition to 490m Sub-Uchaf status was announced
on Mapping Mountains via a Hill Reclassifications post that was published on
the 21.11.20. Its inclusion is due to
LIDAR analysis conducted by Aled Williams, resulting in a 496.0m summit height
and a 477.6m bwlch height, with these values giving this hill 18.4m of
drop. 490m Sub-Uchaf total increases by
one and confirmed as 65.
Twynau
Gwynion 496.8m at SO 06765 10701
 |
| LIDAR image of Twynau Gwynion (SO 067 107) |
This hill’s reclassification back to 490m Sub-Uchaf status
was announced on Mapping Mountains on 02.02.20, with the hill initially listed
as a 490m Sub-Uchaf and consequently reclassified to 490m Double Sub status
based on DTM LIDAR analysis. Its
reinstatement as a 490m Sub-Uchaf is due to DSM LIDAR analysis conducted by
Aled Williams, resulting in a 496.8m summit height and a 481.4m bwlch height,
with these values giving this hill 15.5m of drop. 490m
Sub-Uchaf total increases by one and confirmed as 64.
Cefn Wylfre 490.1m at SO 14585 51034
The addition of this hill to 490m Sub-Uchaf status was announced on the Mapping Mountains site
on the 08.10.17, the hill was previously not classified as with an estimated
drop of c 15m based on the 489m summit spot height that appears on the Ordnance
Survey 1:25,000 map and an estimated bwlch height of c 474m based on bwlch
contouring between 470m – 480m its summit did not reach the minimum qualifying
height of 490m for this sub category.
The hill’s addition to a 490m
Sub-Uchaf is due to analysis of LIDAR data by Aled Williams, with the
resulting 49o.1m summit height and 474.9m bwlch height giving this hill 15.2m
of drop, which when coupled with the hill’s summit height is sufficient for it
to qualify as a 490m Sub-Uchaf. 490m
Sub-Uchaf total increases by one and confirmed as 63.
Pt. 499.1m 499.1m at SN 86343 76073
This hill’s reclassification from an Uchaf was announced on the Mapping Mountains site on the 13.03.17,
with the hill previously listed with an estimated c 500m summit height based on
the flatness of the summit area in relation to the small uppermost 500m ring
contour on Ordnance Survey maps. The
hill’s reclassification to a 490m
Sub-Uchaf is due to analysis of LIDAR data by Aled Williams, with the
resulting 499.1m summit height being too low for the hill to qualify as an Uchaf.
490m Sub-Uchaf total increases
by one and confirmed as 62.
Twynau Gwynion 496.2m at SO 06765 10699
THIS HILL HAS SUBSEQUENTLY BEEN REINSTATED TO 490m SUB-UCHAF STATUS
This hill’s reclassification was announced on the Mapping Mountains site on 10.01.17, with the hill previously listed as a 490m Sub-Uchaf with 16m of drop based on
the 498m summit spot height on the Ordnance Survey 1:50,000 Landranger and
1:25,000 Explorer maps, and a 482m bwlch spot height on the Ordnance Survey
enlarged mapping hosted on the Geograph website. This hill was reclassified from a 490m Sub-Uchaf to a Double Sub-Uchaf from LIDAR data analysed by Aled Williams, resulting
in the hill having a 496.2m summit and 481.3m bwlch height, with these values
giving this hill 14.9m of drop which is insufficient for this hill to retain
its 490m Sub-Uchaf status. 490m
Sub-Uchaf total decreases by one and confirmed as 61.
4th
November 2015 – Mapping Mountains first publishes details to ‘The Welsh Highlands - Uchafion Cymru – 490m
Subs’.
490m
Subs total confirmed as 62.
Myrddyn Phillips and Aled Williams (January 2017)
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