Pt. 522.0m (SJ 136 363) - 500m Sub-Uchaf deletion
There has been a deletion from the listing of Yr Uchafion instigated from analysis of
LIDAR data by Aled Williams. Yr Uchafion is the draft title for a
list of the Welsh 500m P15s that takes in all hills in Wales at or above 500m
that have a minimum drop of 15m, the list is a joint compilation between
Myrddyn Phillips and Aled Williams, with details relating to this list being published
on the Mapping Mountains site in November 2015.
Accompanying the main Yr
Uchafion list are three sub lists; 500m
Sub-Uchaf, 490m Sub-Uchaf and the
Double Sub-Uchaf categories, with the
deletion of this hill affecting the 500m Sub-Uchaf
classification, with the criteria for qualification to this sub category being
all Welsh hills at or above 500m in height that have 14m or more and below 15m
of drop.
Prior to analysis of LIDAR data the hill was listed
with 14m of drop based on the 522m summit spot height that appears on the
Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps and the 508m
bwlch spot height that appears on the Ordnance Survey 1:25,000 Explorer map.
The hill is situated in the Y Berwyn group of hills with its Cardinal Hill being Moel Fferna (SJ 116 397) and is placed
in the Region of North Wales (Region A, Sub-Region A4), and is positioned with
the small communities of Llanarmon
Dyffryn Ceiriog to its south south-east and Pandy to its east.
The hill is situated on open access land and can
be accessed from the south or north-east, with public footpaths making their
way up to higher ground from the stream valleys containing the Afon Ceiriog and the Afon Teirw respectively.
Although a number of local names for the hill
exist it is being catalogued by the point (Pt. 522.0m) notation and its
deletion from the 500m Sub-Uchaf category
is due to the analysis of LIDAR data by Aled Williams. LIDAR (Light Detection & Ranging) is highly
accurate height data that is now freely available for much of England and Wales.
Aled’s analysis of LIDAR data gives the hill the
following details:
Pt. 522.0m
Summit Height: 522.0m
(converted to OSGM15)
Summit Grid Reference:
SJ 13615 36369
Bwlch Height: 508.2m
(converted to OSGM15)
Bwlch Grid Reference:
SJ 13888 36062
Drop: 13.8m
Therefore, the 522.0m (converted to OSGM15) LIDAR
data produced for the summit position at SJ 13615 36369 and the 508.2m (converted to OSGM15) LIDAR data
produced for the bwlch position at SJ 13888 36062 gives
this hill 13.8m of drop which is insufficient for its retention as a 500m Sub-Uchaf.
The full details for the hill are:
Cardinal Hill: Craig
Berwyn
Summit Height: 522.0m
(converted to OSGM15) (LIDAR data)
Name: Pt. 522.0m
OS 1:50,000 map: 125
Summit Grid Reference:
SJ 13615 36369
Drop: 13.8m (converted
to OSGM15) (LIDAR data)
The overall total for Yr
Uchafion / The Welsh 500m P15s remains at 631 hills with the total for the 500m Sub-Uchaf category now being 25
For the additions, reclassifications and deletions to Yr Uchafion / The Welsh 500m P15s
reported on Mapping Mountains please consult the following Change Registers:
Myrddyn Phillips and Aled Williams (April 2017)
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