Carreg y Gwynt (SN 956 776) - Pedwar reclassified to 400m Sub-Pedwar
There has been a reclassification to the listing of Y Pedwarau with a Pedwar being reclassified to the ranks of 400m Sub-Pedwar by analysis of LIDAR data by Aled Williams. The 400m
Sub-Pedwarau is one of five categories of sub hills that accompany the main
Y Pedwarau list, with the criteria
for 400m Sub-Pedwar status being all
Welsh hills at or above 400m and below 500m in height with 20m or more and
below 30m of drop.
The hill is situated in the Pegwn Mawr group with its Cardinal Hill being Garreg Lwyd (SN 942 733) and is placed in the Region of Mid and
West Wales (Region B, Sub-Region B1).
The hill is positioned between the small community of Llangurig to the west north-west and the
town of Llanidloes to the north.
The hill can be ascended from the north, south or
east where public footpaths leave minor narrow roads and circumvent its
summit. As the hill is not a part of
open access land permission to visit its summit should be sought.
The name of the hill is Carreg y Gwynt and prior to the analysis of LIDAR data and its
subsequent listing as a 400m Sub-Pedwar
it had been listed as a Pedwar with 32m
of drop based on a 104ft (31.7m) basic levelling survey conducted by Myrddyn
Phillips on the 23.04.04.
As Aled was analysing other hills in the vicinity
against LIDAR data, he did likewise with Carreg
y Gwynt. 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:
Carreg y Gwynt
Summit Height: 426.7m
Summit Grid Reference: SN 95698 77665
Bwlch Height: 398.6m
Bwlch Grid Reference: SN 95153 78738
Drop: 28.1m
Therefore, the 426.7m LIDAR data produced for the summit
position at SN 95698 77665 and the 398.6m LIDAR data
produced for the bwlch position at SN 95153 78738 is insufficient for this hill
to retain its Pedwar status, and
therefore it is reclassified to a 400m
Sub-Pedwar with 28.1m of drop, and the list of the Y Pedwarau will be updated accordingly.
The full details for the hill are:
Cardinal Hill: Garreg
Lwyd
Summit Height: 426.7m
(LIDAR data)
Name: Carreg y Gwynt
OS 1:50,000 map: 136,
147
Summit Grid Reference:
SN 95698 77665
Drop: 28.1m (LIDAR
data)
This now brings the overall total for Y Pedwarau to 444 hills with seven additions, and ten reclassifications
to 400m Sub-Pedwar status since
publication of the list by Europeaklist in May 2013. The hill will be taken out of the Pedwar list and added to the 400m Sub-Pedwar list in forthcoming
publications. The list of Pedwar hills is available from the
Haroldstreet website (January 2014) with all subsequent changes available via
the Mapping Mountains site, with the list having also commenced publication on
Mapping Mountains on the 30.01.17.
The list of additions and reclassifications from the Pedwar list since the 1st
edition of Y Pedwarau was published
by Europeaklist are as follows:
PEDWAR ADDITIONS
Pt. 499.5m (converted to OSGM15) (SH 665 310) 400m Sub-Pedwar reclassified to Pedwar with 30.3m drop
PEDWAR RECLASSIFICATIONS
Pt. 422.3m (converted to OSGM15) (SO 073 822) Pedwar reclassified to 400m Sub-Pedwar with 29.0m drop
Pt. 407.7m (converted to OSGM15) (SO 180 692) Pedwar reclassified to 400m Sub-Pedwar with 28.3m drop
Carreg y Gwynt (LIDAR data) (SN 956 776) Pedwar reclassified
to 400m Sub-Pedwar with 28.1m of drop
Myrddyn Phillips and Aled Williams (March 2017)
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