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

Lower Field (SJ 137 155) – Trichant reclassified to Sub-Trichant

There has been confirmation of 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 a Trimble GeoXH 6000 survey conducted by Myrddyn Phillips with assistance from Mark Trengove. 

LIDAR image of Lower Field (SJ 137 155)

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 now listed by is Lower Field 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 A490 road farther to its north-east, the B4393 road farther to its north-west, the B4382 road farther to its west and the A495 road farther to its south-east, and has the village of Meifod towards the south-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 as the prioritised summit in the main P30 list with an accompanying note stating; Two points of same height (Gallt y Goedhwch SJ137159), with Gallt y Goedhwch listed as the qualifying P20. 

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

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 24m of drop, based on an estimated c 320m summit height and an estimated c 296m bwlch height, with both heights based on interpolation of 10m contouring that appears on the Ordnance Survey 1:25,000 Explorer map, with the prioritised summit given to Gallt y Goedhwch.

However, it was not until the survey with the Trimble GeoXH 6000 that the details for this hill could be accurately re-assessed.  The hill has also now been analysed by LIDAR (Light Detection & Ranging); a technique which produced highly accurate height data that is now freely available for much of England and Wales. 

The Trimble GeoXH 6000 gathering data at the summit of Lower Field

The Trimble GeoXH 6000 gathering data at the bwlch of Lower Field

Therefore, the confirmation of the reclassification of this hill from Trichant status is due to a Trimble GeoXH 6000 survey, resulting in a 321.1m summit height and a 295.3m bwlch height, with these values giving this hill 25.8m of drop, which is sufficient for it to be classified as a Sub-Trichant. 

 

The full details for the hill are: 

Group:  Foel Cedig 

Name:  Lower Field 

OS 1:50,000 map:  125

Summit Height:  321.1m (converted to OSGM15)                                                           

Summit Grid Reference:  SJ 13704 15586                                     

Bwlch Height:  295.3m (converted to OSGM15) 

Bwlch Grid Reference:  SJ 13681 15650 

Drop:  25.8m 

 

Myrddyn Phillips (August 2022)