Esgair Hir (SN 937 925) – Pedwar reclassified to 400m
Sub-Pedwar
There has been a reclassification to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams. 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 a Pedwar to a 400m Sub-Pedwar. 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 analysis of LIDAR data the hill was
listed with c 51m of drop based on the 448m summit spot height that appears on
the Ordnance Survey 1:25,000 Explorer map and an estimated bwlch height of c
397m based on interpolation of bwlch contouring between 390m – 400m. The reclassification of this hill is
dependent upon the analysis of LIDAR data for it, and its adjacent
south-easterly hill of Bryn Crugog
(SN 941 923), with the height of the highest hill swapping, with this affecting
the critical bwlch of both hills and their status. The Hill Reclassifications post for Bryn Crugog will appear separately.
The hill is situated in the Pumlumon range with its
Cardinal Hill being Bryn Amlwg (SN
921 973) and is placed in the Region
of Mid and West Wales (Region B, Sub-Region B2), and is positioned with the
small community of Llawr-y-glyn towards
its south-west.
As the summit is not a part of designated open
access land permission to visit should be sought, however there are a number of
public footpaths that approach the summit from the south, north and the east,
all meeting just west of the high point of the hill.
The name of the hill is Esgair Hir and its reclassification from Pedwar to 400m Sub-Pedwar 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:
Esgair Hir
Summit Height: 446.5m
Summit Grid Reference: SN 93723 92558
Bwlch Height: 423.7m
Bwlch Grid Reference: SN 94106 92683
Drop: 22.8m
Therefore, the 446.5m LIDAR data produced for the summit
position at SN 93723 92558 and the 423.7m LIDAR data
produced for the bwlch position at SN 94106 92683 gives
this hill 22.8m of drop which is insufficient for its continued inclusion as a Pedwar.
The full details for the hill are:
Cardinal Hill: Bryn
Amlwg
Summit Height: 446.5m
(LIDAR data)
Name: Esgair Hir
OS 1:50,000 map: 136
Summit Grid Reference:
SN 93723 92558
Drop: 22.8m (LIDAR
data)
This reclassification now brings the total for Y Pedwarau to 442 hills with eight
additions, and thirteen 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 22 hills being added and 17 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 (June 2017)
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