Mapping Mountains – Hill Reclassifications – Y Trichant – The 300m Hills of Wales

Cae Talcen Ysgubor (SJ 093 152) – Trichant reclassified to Sub-Trichant

There has been a reclassification to the list of Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Cae Talcen Ysgubor (SJ 093 152)

The criteria for the list that this reclassification applies to are:

Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13^th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1^st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Cae Talcen Ysgubor and this was derived from the Tithe map, and it is adjoined to the Foel Cedig group of hills, which are situated in the southern part of North Wales (Region A, Sub-Region A3), and it is positioned encircled by minor roads, with the B4382 road farther to its west, and has the town of Llanfyllin towards the north-east.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for the main P30 category.

When the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 29m of drop, based on the 331m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 302m bwlch height, based on interpolation of 10m contouring between 300m – 310m. 

Extract from the Ordnance Survey 1:25,000 Explorer map

Since the original publication of the Welsh P30 lists on Geoff Crowder’s v-g.me website there have been a number of maps made available online.  Some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website.  Whilst others were digitally updated such as the Ordnance Survey Vector Map Local that was hosted on the Geograph website and which was entitled the Interactive Coverage Map, whilst others are current and digitally updated such as the interactive mapping on the Magic Maps and WalkLakes websites.

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available Ordnance Survey maps and for this hill it had a 301m bwlch spot height, and when coupled with its 331m summit spot height these values gave this hill 30m of drop.

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 reclassification of this hill to Sub-Trichant status is due to LIDAR analysis, resulting in a 330.8m summit height and a 301.7m bwlch height, with these values giving this hill 29.1m of drop, which is insufficient for it to be classified as a Trichant. 

 

The full details for the hill are: 

Group:  Foel Cedig 

Name:  Cae Talcen Ysgubor 

OS 1:50,000 map:  125

Summit Height:  330.8m (LIDAR)                                                           

Summit Grid Reference:  SJ 09389 15229 (LIDAR) 

Bwlch Height:  301.7m (LIDAR) 

Bwlch Grid Reference:  SJ 09507 15592 (LIDAR) 

Drop:  29.1m (LIDAR) 

 

Myrddyn Phillips (August 2022)