Mapping Mountains – Hill Reclassifications – Welsh Highlands – Uchafion Cymru

Pt. 531.3m (SH 658 469) – Welsh Highland Sub addition 

There has been an addition 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 for the Welsh Highlands – Uchafion Cymru list authored by Aled Williams and Myrddyn Phillips. 

LIDAR image of Pt. 531.3m (SH 658 469)

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

Welsh Highlands – Uchafion Cymru – Welsh hills at or above 500m in height with 15m minimum drop, with an accompanying sub list entitled the Welsh Highland Subs, the criteria for which is all Welsh hills at or above 500m in height with 10m or more and below 15m of drop.  This list is authored by Myrddyn Phillips and Aled Williams with the Introduction to the list published on Mapping Mountains in November 2015 and the latest update relating to the list published on Mapping Mountains in January 2023.

Welsh Highlands - Uchafion Cymru by Myrddyn Phillips and Aled Williams

The hill is being listed by the point (Pt. 531.3m) notation and it is adjoined to the Moelwyn Mawr group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A2), and it is positioned with a minor road to its west, the A4085 road to its south-west, the B4410 road to its south and the A470 road to its east, and has the town of Blaenau Ffestiniog towards the east south-east.

This hill was not included in the initial P10 sub list when it was completed in June 2020 as with a 531m summit spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map and an estimated c 523m bwlch height, based on interpolation of 10m contouring between 520m – 530m, these values gave this hill an estimated c 8m of drop. 

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 addition of this hill to Welsh Highland Sub status is due to LIDAR analysis, resulting in a 531.3m summit height and a 520.6m bwlch height, with these values giving this hill 10.6m of drop, which is sufficient for it to be classified as a Welsh Highland Sub. 

 

The full details for the hill are: 

Group:  Moelwyn Mawr

Name:  Pt. 531.3m

OS 1:50,000 map:  115

Summit Height:  531.3m (LIDAR)

Summit Grid Reference:  SH 65884 46911 (LIDAR)

Bwlch Height:  520.6m (LIDAR)

Bwlch Grid Reference:  SH 65971 46821 (LIDAR)   

Drop:  10.6m (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 (May 2023)