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

Moel Smytho (SH 520 576) – Sub-Trichant reclassified to Trichant

There has been confirmation of a reclassification 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 Moel Smytho (SH 520 576)

The criteria for the list that this reclassification 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 13th May 2017.

The name the hill is listed by is Moel Smytho 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 Afon Gwyrfai and the A4085 road to its north-east, and has the village of Waunfawr towards the north.

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When the sub list was 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 30m of drop, based on the 343m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated bwlch height of c 313m based on interpolation of contouring between 310m – 320m.

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

The details for this hill were re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map became available online.  This mapping has many spot heights not on other publicly available Ordnance Survey maps and gives a 311m spot height on the area of this hill’s bwlch.  This spot height is also shown on Ordnance Survey data that appears on the Magic Maps website.  The bwlch spot height coupled with the 343m summit spot height confirmed this hill’s Trichant status with 32m of listed drop.   

Extract from the Magic Maps website

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. 

The confirmation of the reclassification of Moel Smytho from Sub-Trichant status is due to LIDAR analysis, resulting in a 341.9m summit height and a 310.5m bwlch height, with these values giving this hill 31.4m of drop which is sufficient for it to be classified as a Trichant.

The full details for the hill are:

Group:  Moel Hebog

Name:  Moel Smytho

OS 1:50,000 map:  115

Summit Height:  341.9m (LIDAR)

Summit Grid Reference:  SH 52096 57676 (LIDAR)

Bwlch Height:  310.5m (LIDAR)

Bwlch Grid Reference:  SH 52151 57266 (LIDAR)

Drop:  31.4m (LIDAR)

Myrddyn Phillips (January 2020)