Mapping Mountains – Hill Reclassifications – Welsh Highlands – Uchafion Cymru

Pt. 576.0m (SH 559 475) – Welsh Highland Sub reclassified to Welsh Highland P15 

There has been a reclassification 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. 576.0m (SH 559 475)

The criteria for the list that this reclassification 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. 576.0m) notation, and it is adjoined to the Moel Hebog group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with the B4418 road to its north, the A487 road to its west and the A4085 road to its north-east, and has the village of Beddgelert towards the east.

When the original list that later became known as the Welsh Highlands – Uchafion Cymru was first compiled, this hill was not included as a Welsh Highland Sub as with no separate uppermost ring contour on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map there was no map evidence to suggest that any form of hill with qualifying prominence existed. 

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

Since the original compilation of this list there are now a number of interactive maps originated from Ordnance Survey data that are available online.  One of these is the mapping on the Magic Maps website, and this map gives this hill a summit spot height of 576m which is positioned at SH 55928 47522.

Another resource now available online is the WalkLakes website which hosts an interactive map originated from the Ordnance Survey Open Data programme.  This map has many spot heights not on other publicly available Ordnance Survey maps and for this hill it also shows the 576m summit spot height. 

Extract from the interactive mapping hosted on the WalkLakes website

The details for this hill were also re-examined against the Ordnance Survey non-contour Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map.  This is another map that has many spot heights that do not appear on other publicly available Ordnance Survey maps and it also gives a 576m summit spot height.

The details for this hill were also re-assessed when the OS Maps website became available online.  This is the replacement for OS Get-a-map and had contours at 5m intervals which were proving consistently more accurate compared to the 5m contours that sometimes appear on Ordnance Survey 1:25,000 Explorer maps and used to appear on the online Vector Map Local.  This mapping has bwlch contouring between 560m – 565m, with interpolation giving an estimated c 562m bwlch height.

The above interactive mapping prompted the addition of this hill to Welsh Highland Sub status and it was listed with an estimated c 14m drop, based on the 576m summit spot height and an estimated c 562m bwlch height.

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 from Welsh Highland Sub status is due to LIDAR analysis, resulting in a 576.0m summit height and a 560.4m bwlch height, with these values giving this hill 15.6m of drop, which is sufficient for it to be classified as a Welsh Highland P15.

 

The full details for the hill are: 

Group:  Moel Hebog

Name:  Pt. 576.0m

OS 1:50,000 map:  115

Summit Height:  576.0m (LIDAR)

Summit Grid Reference:  SH 55928 47521 (LIDAR)

Bwlch Height:  560.4m (LIDAR)

Bwlch Grid Reference:  SH 55885 47595 (LIDAR)   

Drop:  15.6m (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 (June 2023)