Esgair y Llyn (SN 841
701) - Uchaf addition
There has been an addition to the listing of Yr Uchafion
instigated from map study and confirmed by LIDAR analysis conducted by Aled
Williams and a subsequent Trimble GeoXH 6000 survey conducted by Myrddyn Phillips and Aled Williams.
Yr Uchafion is the draft title
for a list of the Welsh 500m P15s that takes in all hills in Wales at or above
500m that have a minimum of 15m of drop, the list is a joint compilation with
Aled Williams. Details relating to this
list were published on the Mapping Mountains site in November 2015.
The hill is situated in the Elenydd group of hills
in the central part of Mid and West Wales.
This grouping of hills forms one of the wildest in Wales and takes in
some of the most remote hills in the country.
The hill is situated in an immense grassland of moor and tussocks with Llyn
Cerrigllwydion Isaf to its south-east and the higher summits of Cnapyn
Drawsffos (SN 834 706) to its north-west and Blaen Rhestr (SN 843 693) towards
its south. Any towns or villages are a
far distance away with Ysbyty Ystwyth towards the west and Rhaeadr Gwy
(Rhayader) towards the east.
The hill can be accessed from its north-east via a
track that leads to the farmhouse of Glanhirin, a path then leads toward and up
the north-eastern ridge of Blaen Rhestr.
However, an alternate route would be using the Monks Trod, which is an
ancient route across the hills developed by the Cistercian monks as a bi-way
between the abbeys of Cwm-Hir and Strata Florida. Whichever way is chosen it leads into land
that is open and somewhat featureless.
The name of the hill is Esgair y Llyn and its
inclusion as an Uchaf was spotted by Aled as the Ordnance Survey enlarged
mapping on the Geograph website gives this hill a 529m summit spot height and a
513m bwlch spot height, this 16m of drop is sufficient to enter the list of
Uchafion.
As Aled was analysing other hills in the vicinity
against LIDAR data, he did likewise with Esgair y Llyn. LIDAR (Light Detection & Ranging) is highly
accurate height data that is now freely available for much of England and
Wales, and as mentioned in the first paragraph of this post; if Esgair y Llyn has
a minimum of 15m of drop it would be included in the listing of Welsh hills at
or over 500m in height that has a minimum of 15m of drop, and has the working
title of Yr Uchafion.
Aled’s analysis of LIDAR
data gave the hill a 528.8m summit height at SN 84118 70177, and a 513.3m bwlch
height at SN 83811 70087, these values give this hill 15.5m of drop which is
sufficient for qualification as an Uchaf.
The subsequent Trimble GeoXH 6000 survey produced a summit height of 528.6m and a bwlch height of 513.0m, with these values giving this hill 15.6m of drop, which is sufficient for this hill to be classified as an Uchaf.
This now revises the total in Yr Uchafion which will be
updated accordingly and the hill is now listed as an Uchaf.
The full details for the hill are:
Cardinal Hill: Carn yr
Hyrddod
Summit Height: 528.6m
(converted to OSGM15)
Name: Esgair y Llyn
OS 1:50,000 map: 135,
136, 147
Summit Grid Reference:
SN 84116 70174
Drop: 15.6m
 |
| Esgair y Llyn (SN 841 701) |
The reclassifications to Yr Uchafion / The Welsh 500m P15s
reported on Mapping Mountains are as follows:
UCHAF ADDITIONS
Esgair y Llyn (LIDAR data) (SN 841 701) added as an Uchaf with 15.5m of
drop.
UCHAF RECLASSIFICATIONS
UCHAF DELETIONS
Myrddyn Phillips and Aled Williams (December 2016)
No comments:
Post a Comment