Tuesday, 8 March 2016

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


Moel y Gadair (SH 521 391) - Lesser Dominant deletion

There has been a deletion from the listing of Y Trechol – The Dominant Hills of Wales due to a survey with the Trimble GeoXH 6000 and which has resulted in the hill being taken out of The Lesser Welsh Dominant list and subjected to a life of rather pitiful non dominance.

The hill is in positioned in the Moel Hebog group and is situated on the south-western outskirts of the small community of Pentrefelin, which is positioned between the towns of Porthmadog to its east and Cricieth to its south-west.

The Trimble GeoXH 6000 survey that resulted in this hill’s deletion was conducted over two days, with the hill’s summit being surveyed on the 15th June 2015 in warm and sunny conditions, and the bwlch being surveyed on the 23rd February 2016 on a beautiful winter’s day.

If wanting to visit the hill it can be accessed from a public footpath to its south-west, but as its summit is not on open access land permission to visit its high point should be sought.

The name of the hill is Moel y Gadair and it had been listed with 45.05% Dominance and a drop value of c 30m, with the latter figure the minimum required for qualification to the Dominance list.  These figures were based on a summit survey of 66.7m (converted to OSGM15) and an interpolated bwlch height of c 37m based on bwlch contouring between 35m – 40m.  During the 15th June 2015 survey the contours at the bwlch had been misinterpreted resulting in the second bwlch survey which was conducted on the 23rd February 2016 and which resulted in a bwlch height of 38.1m (converted to OSGM15).

The survey with the Trimble GeoXH 6000 resulted in a 66.7m (converted to OSGM15) summit height and a 38.1m (converted to OSGM15) bwlch height, giving this hill a drop of only 28.5m which is insufficient for qualification to the Dominant list.


The full details for the hill are:

Group:  Moel Hebog

Name:  Moel y Gadair

Dominance:  N/A

OS 1:50,000 map:  124

Summit Grid Reference:  SH 52165 39135

Summit Height:  66.7m (converted to OSGM15)

Drop Summit to Bwlch:  28.5m

Drop Bwlch to ODN:  38.1m (converted to OGM15)  


The final nail in the coffin - gathering data at the critical bwlch of Moel y Gadair (SH 521 391)  which resulted in this hill's deletion from the Lesser Welsh Dominant list

For details on the survey that resulted in this hill being demoted from The Lesser Welsh Dominant list please click {here} for summit and {here} for the bwlch survey.


Myrddyn Phillips (February 2016)


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