Pt. 505.5m (SH 967 199) – Welsh Highland
Sub deletion
There has been a deletion to the listing of the Welsh Highlands – Uchafion Cymru, with the summit height, bwlch height
and their locations, the drop and status of the hill derived from LIDAR
analysis conducted by Aled Williams.
|
LIDAR image of Pt. 505.5m (SH 967 199) |
The criteria for the list that this deletion applies to are:
|
Welsh Highlands - Uchafion Cymru by Myrddyn Phillips and Aled Williams |
The hill is being listed by the point (Pt. 505.5m)
notation and it is adjoined to the Esgeiriau Gwynion group of hills, which are situated in the southern part of North
Wales (Region A, Sub-Region A3), and
it is positioned with the B4343 road to its north-east and a minor road to its south-east,
and has the village of Llanwddyn towards the east.
When the initial P10 sub list was completed in
June 2020 this hill was listed with an estimated c 10m of drop, based on the 506m
summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and
1:25,000 Explorer map, and an estimated c 496m bwlch height, based on
interpolation of 5m contouring that appeared online.
|
Extract from the Ordnance Survey 1:25,000 Explorer map |
However, it was not until LIDAR became available
that the details for this hill could be accurately re-assessed. The LIDAR (Light Detection & Ranging)
technique produced highly accurate height data that is now freely available for
much of England and Wales.
Therefore, the deletion of this hill from Welsh
Highland Sub status is due to LIDAR analysis, resulting in a 505.5m summit
height and a 497.1m bwlch height, with these values giving this hill 8.4m of
drop, which is insufficient for it to be classified as a Welsh Highland
Sub.
The full details for the hill are:
Group: Esgeiriau
Gwynion
Name: Pt. 505.5m
OS 1:50,000 map: 125
Summit Height: 505.5m
(LIDAR)
Summit Grid Reference:
SH 96714 19988 (LIDAR)
Bwlch Height: 497.1m
(LIDAR)
Bwlch Grid Reference:
SH 96813 20159 (LIDAR)
Drop: 8.4m
(LIDAR)
For the additions, deletions and reclassifications to the Welsh Highlands – Uchafion Cymru
reported on Mapping Mountains please consult the following Change Registers:
Welsh Highland P15s
Welsh Highland Subs
Aled Williams and Myrddyn Phillips (September 2023)
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