Cwm Cynnydd Bank (SO 053 724) - 400m Sub-Pedwar reclassified to Pedwar
There has been a reclassification to the listing of the Y Pedwarau with a 400m Sub-Pedwar being reclassified to Pedwar status due to 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, with the criteria for Pedwar
status being all Welsh hills at or above 400m and below 500m in height with
a minimum 30m of drop.
The hill is situated in the Pegwn Mawr group with its Cardinal Hill being Brondre Fawr Hill (SO 041 783) and is placed in the Region of Mid
and West Wales (Region B, Sub-Region B1), and is positioned between the small
communities of Bwlch y Sarnau to the
north-west and Abaty Cwm Hir (Abbey
Cwmhir) to the south.
The summit of the hill is situated in conifer
plantation but the hill can be accessed via forestry tracks from a number of
directions as these encircle the upper part of the hill. The forestry track towards the north-east and
also the south-west of the summit gives access to a forest ride that passes
within a few metres and to the east of the high point of the hill.
The name of the hill is Cwm Cynnydd Bank (previously listed in Y Pedwarau as Pt. 444m,
Cwmcynydd Bank) and prior to the
analysis of LIDAR data and its subsequent listing as a Pedwar the hill had been listed as a 400m Sub-Pedwar with c 27m of drop based on the 444m spot height
that appears at SO 05234 72506 on the Ordnance Survey 1:25,000 Explorer map and
an estimated bwlch height of c 417m at SO 05783 72592.
As Aled was analysing other hills in the vicinity
against LIDAR data, he did likewise with Cwm Cynnydd
Bank. 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:
Cwm Cynnydd Bank
Summit Height: 451.4m
Summit Grid Reference: SO 05342 72437
Summit Height: 451.4m
Summit Grid Reference: SO 05342 72437
Bwlch Height: 416.4m
Bwlch Grid Reference: SO 05788 72576
Drop: 35.0m
Therefore, the 451.4m LIDAR data produced for the summit
position at SO 05342 72437 and the 416.4m LIDAR data produced for the bwlch position at SO 05788 72576 gives this hill 35.0m of drop which is sufficient for its reclassification from a 400m Sub-Pedwar to a Pedwar.
The full details for the hill are:
Cardinal Hill: Brondre
Fawr Hill
Summit Height: 451.4m
(LIDAR data)
Name: Cwm Cynnydd Bank
OS 1:50,000 map: 136,
147
Summit Grid Reference:
SO 05342 72437
Drop: 35.0m (LIDAR data)
This now brings the overall total for Y Pedwarau to 445 hills with eight 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 400m Sub-Pedwar list and added to the 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 also having 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 the 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
Cwm Cynnydd Bank (LIDAR data) (SO 053 724) 400m Sub-Pedwar reclassified to
Pedwar with 35.0m 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
Myrddyn Phillips and Aled Williams (March 2017)
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