Friday, 4 March 2016

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

Moelfre (SH 558 375) - Dominant reclassified to Lesser Dominant

There has been a reclassification 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 Dominant list and included in the Lesser Welsh Dominant list.  The hill is in the Group known as Moel Hebog and is situated to the south-west of Porthmadog, overlooking the coast and above the small community of Borth-y-gest.

The Trimble GeoXH 6000 survey that resulted in this hill’s reclassification was conducted on the 23rd February 2016 on a beautiful winter’s morning in sunny conditions.

The hill can be accessed from its west, east, south and north, with my two visits starting from the south and north respectively.  Access to mid-way up the hill can be gained via public footpaths but the high point is not on open access land, so permission to visit should be sought.

The hill remains unnamed on current Ordnance Survey maps but local enquiry with Aled Williams; a native of Porthmadog, confirms that the hill is known locally as Moelfre.

The hill had been listed with 50.00% of Dominance and was therefore included in the main Dominant list.  This was based on it having a 74m summit spot height on the Ordnance Survey enlarged mapping hosted on the Geograph website and an estimated bwlch height of c 37m based on bwlch contouring between 35m – 40m, these values gave the hill a prominence of c 37m, which was enough for it to sneak into the main Dominant list.

The survey with the Trimble GeoXH 6000 resulted in a 74.1m (74.056m, converted to OSGM15) summit height and a 37.8m (37.770m, converted to OSGM15) bwlch height, giving this hill a Dominance of only 49.00% and confirming its reclassification from The Dominant Hills of Wales list to The Lesser Welsh Dominant list.

The full details for the hill are:

Group:  Moel Hebog

Name:  Moelfre

Dominance:  49.00%

OS 1:50,000 map:  124

Summit Grid Reference:  SH 55830 37553

Summit Height:  74.1m (converted to OSGM15)

Drop Summit to Bwlch:  36.3m

Drop Bwlch to ODN:  37.8m (converted to OSGM15)  

Moelfre (SH 558 375) now reclassified to the Lesser Welsh Dominant list

For details on the survey that resulted in this hill being reclassified to a Lesser Welsh Dominant hill please click {here}

Myrddyn Phillips (February 2016)

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