Saturday 27 May 2017

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


Coed y Garth (SH 661 165) – Lesser Dominant addition (subsequently deleted)

Due to LIDAR analysis initially conducted by Chris Crocker and George Gradwell, and subsequently by Myrddyn Phillips, this hill has been deleted from the Lesser Dominant list as with 27.1m of drop it does not qualify.



There has been an addition to the listing of Y Trechol – The Dominant Hills of Wales which has resulted in the hill being added to the Lesser Welsh Dominant list.  The criteria for inclusion in this category of sub list is those P30 hills whose prominence is 33% or more and below 50% of their absolute height.

The details relating to this hill’s inclusion as a Lesser Welsh Dominant hill are retrospective as it appeared in the Cadair Idris group of hills when published on the Mapping Mountains site on the 3rd November 2016.

The hill did not appear in the original listing of Y Trechol – The Dominant Hills of Wales as Ordnance Survey maps only gave the summit of the hill as having an uppermost ring contour of 80m, and with bwlch contouring between 50m – 60m the drop had been estimated as being below the minimum of 30m required for consideration for this list.

Since this list’s inception online mapping has improved and it is details on the Ordnance Survey enlarged mapping hosted on the Geograph website combined with the Harvey 1:25,000 Cadair Idris Superwalker map that has both bwlch and summit spot heights for this hill, with the former being 56m and the latter 87m, with these values giving 31m of drop and 35.63% Dominance.

The hill is listed in the Cadair Idris group and is placed in the Region of North Wales (Region A, Sub-Region A3) with its Cardinal Hill being Cadair Idris (SH 711 130), and it is situated between the small communities of Arthog to the south-west and Abergwynant to the east north-east.

As the hill is situated in conifer plantation a route to its summit may prove problematic, with access from the track that crosses its bwlch to the north-east possibly offering the quickest approach.

The name of the hill is Coed y Garth and it qualifies for Lesser Welsh Dominant status based on the 87m summit spot height on the Harvey 1:25,000 Cadair Idris Superwalker map and the 56m bwlch spot height on the Ordnance Survey enlarged mapping hosted on the Geograph website, with these values giving this hill 31m of drop and 35.63% Dominance.
   

The full details for the hill are:

Group:  Cadair Idris

Name:  Coed y Garth

Dominance:  35.63%

OS 1:50,000 map:  124

Summit Grid Reference:  SH 66100 16583

Summit Height:  87m

Drop Summit to Bwlch:  31m

Drop Bwlch to ODN:  56m 



Myrddyn Phillips (May 2017)











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