Mapping Mountains – Hill Reclassifications – The Welsh P15s

 

Pt. 52.0m (SH 341 800) – Welsh Sub-P15 deletion

There has been a deletion to the list of The Welsh P15s, 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 Pt. 52.0m (SH 341 800)

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

The Welsh P15s – Welsh hills with 15m minimum drop, irrespective of their height, with an accompanying sub list entitled the Welsh Sub-P15s, with the criteria for this sub category being all Welsh hills with 14m or more and below 15m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list appearing on Mapping Mountains on the 10^th May 2019. 

The Welsh P15s by Myrddyn Phillips

The hill is being listed by the point (Pt. 52.0m) notation as an appropriate name for it either through local enquiry and / or historic research has not been found by the author, and it is adjoined to the Ynys Môn 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 coast to its west, a minor road beside its summit, the B5109 road to its north and the A5 and A55 roads to its south, and has the village of Bodedern towards the west. 

When the listing that became known as The Welsh P15s was being compiled, this hill was included in the P14 sub list with 14m of drop, based on the 52m 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 the 38m bwlch spot height that appears on the Ordnance Survey 1:25,000 Explorer map. 

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 deletion of this hill from Welsh Sub-P15 status is due to LIDAR analysis, resulting in a 52.0m summit height and a 38.45m bwlch height, with these values giving this hill 13.6m 0f drop, which is insufficient for it to be classified as a Welsh Sub-P15. 

 

The full details for the hill are: 

Group:  Ynys Môn 

Name:  Pt. 52.0m 

OS 1:50,000 map:  114

Summit Height:  52.0m (LIDAR)                                                           

Summit Grid Reference:  SH 34189 80031 (LIDAR) 

Bwlch Height:  38.45m (LIDAR) 

Bwlch Grid Reference:  SH 34589 80216 (LIDAR) 

Drop:  13.6m (LIDAR) 

 

Myrddyn Phillips (October 2021)