Mapping Mountains – Hill Reclassifications – Y Pedwarau

Moel yr Acre (SJ 169 526) – 400m Sub-Pedwar deletion

There has been a deletion to the listing of Y Pedwarau due to analysis of data on the OS Maps website, which is the recent replacement for OS Get-a-map.

Moel yr Acre (SJ 169 526)

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

Y Pedwarau – The 400m Hills of Wales.  Welsh hills at or above 400m and below 500m in height with 30m minimum drop, accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being deleted from the 400m Sub-Pedwar category.  The criteria for 400m Sub-Pedwar status being all Welsh hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and is published on Mapping Mountains in Google Doc format.

The name of the hill is Moel yr Acre, and it is adjoined to the Bryniau Clwyd 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 A525 road to its south, the B5429 road to its north-west and the B5431 road its north-east, and has the town of Rhuthun (Ruthin) towards the north-west.

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

Prior to analysis of data on OS Maps this hill was listed with c 20m of drop based on the 411.3m summit height ascertained from a Leica GS15 survey conducted by John Barnard and Myrddyn Phillips and an estimated bwlch height of c 391m based on interpolation of bwlch contouring between 390m – 395m on the Ordnance Survey 1:25,000 Explorer map.

Extract from the OS Maps website

The deletion of Moel yr Acre from 400m Sub-Pedwar status is due to the analysis of data on the OS Maps website and a re-assessment of bwlch contouring on the Ordnance Survey 1:25,000 Explorer map.  Therefore with a 411.3m summit height from the Leica GS15 survey and an estimated bwlch height of c 392m, based on bwlch contouring on OS Maps between 390m – 395m, this hill is now listed with c 19m of drop, which is insufficient for it to be classified as a 400m Sub-Pedwar. 

The full details for the hill are:

Group:  Bryniau Clwyd

 

Name:  Moel yr Acre

OS 1:50,000 map:  116

Summit Height:  411.3m (converted to OSGM15)

Summit Grid Reference:  SJ 16955 52668

Bwlch Height:  c 392m

Bwlch Grid Reference:  SJ 16994 53034 (interpolation)

Drop:  c 19m

For the additions, reclassifications and deletions to Y Pedwarau reported on Mapping Mountains since the May 2013 publication of the list by Europeaklist please consult the following Change Registers:

Y Pedwarau

Y Pedwarau – 400m Sub-Pedwarau

Y Pedwarau – 390m Sub-Pedwarau

Y Pedwarau – 390m Double Sub-Pedwarau

Myrddyn Phillips and Aled Williams (October 2019)