Mapping Mountains – Hill Reclassifications – Y Trechol – The Dominant Hills of Wales

 

The Park (SN 664 936) – Lesser Dominant reclassified to Dominant

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

LIDAR image of The Park (SN 664 936)

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

Y Trechol – The Dominant Hills of Wales – Welsh P30 hills whose prominence equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height.  The list is authored by Myrddyn Phillips with the Introduction to the start of the Mapping Mountains publication of this list appearing on the 3^rd December 2015, and the list is now available in its entirety on Mapping Mountains in Google Doc format. 

Y Trechol - The Dominant Hills of Wales by Myrddyn Phillips

The name the hill is listed by is The Park, and it is adjoined to the Pumlumon group of hills which are situated in the north-western part of Mid and West Wales (Region B, Sub-Region B2), and it is positioned with the Afon Dyfi to its north, the coast to its west and the A487 road to its east, and has the village of Tal-y-bont towards the south. 

When the original 30-99m height band of Welsh P30 hills published on Geoff Crowder’s v-g.me website were 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 41m drop and 49.40% dominance, based on an estimated c 83m summit height and the 42m 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 reclassification of this hill from Lesser Dominant status is due to LIDAR analysis, resulting in an 85.6m summit height and a 42.7m bwlch height, with these values giving this hill 42.9m drop and 50.09% dominance, which is insufficient for it to be classified as a Dominant hill. 

 

The full details for the hill are:

Group:  Pumlumon

Name:  The Park 

OS 1:50,000 map:  135

Summit Grid Reference:  SN 66441 93678 (LIDAR)

Summit Height:  85.6m (LIDAR)

Bwlch Grid Reference:  SN 66477 93308 (LIDAR)

Drop Summit to Bwlch:  42.9m (LIDAR)

Drop Bwlch to ODN:  42.7m (LIDAR)

Dominance:  50.09% (LIDAR)

 

Myrddyn Phillips (July 2021)