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

 

Mountain Park (SJ 094 443) – Trichant deletion

There has been a deletion 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 confirmed by LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Mountain Park (SJ 094 443)

The criteria for the list that this deletion 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. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Mountain Park, and this was derived from the Tithe map, and it is adjoined to the Moel y Gamelin group of hills, which are situated in the north-eastern part of North Wales (Region A, Sub-Region A2), and it is positioned with the A5104 road to its north, the B5437 road to its south and the B5436 road to its east, and has the village of Carrog towards the south-east. 

When the original 300m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website, this hill was included in the main P30 list and given twin topped 314m map heighted summit status along with its adjacent hill positioned at SJ 091 444. 

After the P30 lists were standardised and interpolated heights and drop values also included, this hill was listed as the priority summit with an estimated c 91m of drop based on the 314m summit spot height and an estimated c 223m bwlch height based on interpolation of 10m contouring between 220m – 230m that appear on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, with its adjacent 314m twin summit given non-priority status and listed with 18m of drop based on the 314m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 296m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map. 

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

However, it was not until LIDAR became available that the details for these two summits 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.

 

LIDAR gives the following detail for each summit: 

313.0m positioned at SJ 09438 44364. 

313.1m positioned at SJ 09125 44411.

 

Therefore, the deletion of this hill from prioritised Trichant status is due to LIDAR analysis, resulting in a 313.0m summit height and a 295.7m bwlch height, with these values giving this hill 17.3m of drop, which is insufficient for it to be classified as a Trichant. 

 

The full details for the hill are: 

Group:  Moel y Gamelin 

Name:  Mountain Park 

OS 1:50,000 map:  125

Summit Height:  313.0m (LIDAR)                                                           

Summit Grid Reference:  SJ 09438 44364 (LIDAR) 

Bwlch Height:  295.7m (LIDAR) 

Bwlch Grid Reference:  SJ 09279 44430 (LIDAR) 

Drop:  17.3m (LIDAR) 

 

Myrddyn Phillips (February 2021)