Mapping Mountains – Hill Reclassifications – Y Pedwarau

Pt. 442.9m (SN 945 643) – 400m Sub-Pedwar addition

There has been an addition to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams.  Y Pedwarau is the title for the list of 400m hills of Wales and takes in all Welsh hills at or above 400m and below 500m in height that have a minimum 30m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and it commenced publication on Mapping Mountains on the 30.01.17.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this hill being included in the 400m Sub-Pedwar category.  The criteria for 400m Sub-Pedwar qualification is all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop.

Prior to analysis of LIDAR data the hill was not classified as its uppermost 430m ring contour that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps and bwlch contouring between 420m – 430m did not even warrant it an estimated P14m.

The hill is situated in the Elenydd range with its Cardinal Hill being Gorllwyn (SN 917 590), and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2), and is positioned above the small community of the Elan Village to its north-west and Llanwrthwl to its east south-east.

The summit of the hill is a part of designated open access land and has public footpaths approaching it from the north, south-west, south and south-east, all of which bisect with the open access land.

The name of the hill is being listed under the point (Pt. 442.9m) notation as the authors do not know an appropriate name for it either from local enquiry or from historical research, and its addition to 400m Sub-Pedwar status is due to the analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:

Pt. 442.9m

Summit Height:  442.9m 

Summit Grid Reference:  SN 94528 64354

Bwlch Height:  422.3m

Bwlch Grid Reference:  SN 94272 64477

Drop:  20.6m

Therefore, the 442.9m LIDAR data produced for the summit position at SN 94528 64354 and the 422.3m LIDAR data produced for the bwlch position at SN 94272 64477 gives this hill 20.6m of drop which is sufficient for its inclusion as a 400m Sub-Pedwar.

The full details for the hill are:

Cardinal Hill:  Gorllwyn

Summit Height:  442.9m (LIDAR data)

Name:  Pt. 442.9

OS 1:50,000 map:  147

Summit Grid Reference:  SN 94528 64354

Drop:  20.6m (LIDAR data)

The total for Y Pedwarau remains at 442 hills with nine additions, and fourteen reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.

The overall total for the 400m Sub-Pedwarau is now 219 with 26 hills being added and 20 hills being taken out of this category since publication of the list by Europeaklist in May 2013.

The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes detailed on the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

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 (August 2017)