Waun Sidan (SO 250 726) – 400m Sub-Pedwar reclassified to
Pedwar
There has been a reclassification to the listing of Y Pedwarau due to LIDAR analysis conducted by Aled Williams and subsequently confirmed via a survey with the Trimble GeoXH 6000. Y Pedwarau is the title for the list of 400m hills of Wales and
takes in all Welsh hills at or above 400m and below 500m in height that have a
minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips
and Aled Williams and it commenced publication on Mapping Mountains on the
30.01.17.
Accompanying the main Y
Pedwarau list are five categories of sub hills, with this hill being reclassified
from the 400m Sub-Pedwar category. The
criteria for 400m Sub-Pedwar
qualification is all Welsh hills at or above 400m and below 500m in height with
20m or more and below 30m of drop.
Prior to LIDAR analysis this hill was
listed with 29m of drop based on a basic levelling survey (BLS) conducted by
Myrddyn Phillips on the 05.10.03, with the summit height listed as 406m which
is taken from the spot height that appears on the Ordnance Survey 1:25,000
Explorer map, based on the map summit height and the BLS these values place the
height of the bwlch at 377m.
 |
| Extract from the Ordnance Survey 1:25,000 Explorer map |
The name of the hill is Waun Sidan and it is situated in the Maelienydd range of hills with its Cardinal Hill being Bwlch Bank (SO 242 720) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B1). The hill is positioned above the B 4355 road and the River Teme which are to its north-east, and the A 488 road which is to its south, with the town of Trefyclo (Knighton) towards the east.
 |
| Waun Sidan (SO 250 726) |
As the summit of the hill is not a part of designated open access land permission to visit should be sought, for those wishing to do so the long distance footpath of Glyndŵr’s Way passes just to the south of the summit.
The reclassification of Waun Sidan to Pedwar status is due to the LIDAR analysis conducted 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:
Waun Sidan
Summit Height: 407.7m
Summit Grid Reference:
SO 25021 72649
Bwlch Height: 376.3m
Bwlch Grid Reference: SO 24638 72691
Drop: 31.4m
Therefore, the 407.7m LIDAR data produced for the summit
position at SO 25021 72649 and the 376.3m LIDAR data
produced for the bwlch position at SO 24638 72691 gives
this hill 31.4m of drop which is sufficient for it to be classified as a Pedwar, with the details from the Trimble GeoXH 6000 survey being 407.8m (converted to OSGM15) summit height at SO 25022 72649 and 376.3m (converted to OSGM15) bwlch height at SO 24638 72691, giving this hill 31.5m of drop.
The full details for the hill are:
Cardinal Hill: Bwlch
Bank
Summit Height: 407.8m (converted to OSGM15)
Name: Waun Sidan
OS 1:50,000 map: 137,
148
Summit Grid Reference:
SO 25022 72649
Drop: 31.5m (converted to OSGM15)
The total for Y
Pedwarau is now 443 hills with ten
additions, and fourteen reclassifications to 400m Sub-Pedwar status since publication of the list by
Europeaklist in May 2013.
The overall total for the 400m
Sub-Pedwarau is now 218 with 27 hills being added and 22 hills being taken
out of this category since publication of the list by Europeaklist in May 2013.
The list of Pedwar
hills is available from the Haroldstreet website (January 2014) with all
subsequent changes detailed on the Mapping Mountains site, with the list also
having commenced publication on Mapping Mountains on the 30.01.17.
For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains
since the May 2013 publication of the list by Europeaklist please consult the
following Change Registers:
Myrddyn Phillips and Aled Williams (September 2017)
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