Wednesday, 28 December 2016

Mapping Mountains – Hill Reclassifications – Y Pedwarau


Pt. 408.4m (SO 186 070) - 400m Sub-Pedwar addition

There has been a new 400m Sub-Pedwar added to the list of the Y Pedwarau by analysis of LIDAR data by Aled Williams.  The 400m Sub-Pedwarau are the Welsh hills at or above 400m and below 500m in height with a drop between 20m and below 30m.

The hill is situated in the group of hills known as the Y Cymoedd with its Cardinal Hill being Mynydd Carn y Cefn (SO 187 085) and is placed in the Region of South Wales (C-2).  The hill is positioned above the small community of Waunlwyd to its west and the small town of Blaenau to its east north-east, and can be easily accessed from a track to its south.

As the authors have not confirmed a locally known name for the hill we are following the point (Pt. 408.4m) notation principal and listing it as Pt. 408.4m, and prior to the analysis of LIDAR data the hill was not included in any hill list as the map details for it are blank, this is because the hill is a part of old mine workings and the result of waste spoil.

As Aled was analysing other hills in the vicinity against LIDAR data, he did likewise with Pt. 408.4m.  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. 408.4m

Summit Height:  408.4m

Summit Grid Reference:  SO 18603 07087

Bwlch Height:  386.4m

Bwlch Grid Reference:  SO 18464 07321

Drop:  22.0m

Therefore, the 408.4m LIDAR data produced for the summit position at SO 18603 07087 and the 386.4m LIDAR data produced for the bwlch position at SO 18464 07321 is sufficient for this hill to be classified as a 400m Sub-Pedwar with 22.0m of drop, and therefore Pt. 408.4m is included in the listing of 400m Sub-Pedwar hills and the list of the Y Pedwarau will be updated accordingly.  The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes available via the Mapping Mountains site.


The full details for the hill are:

Cardinal Hill:  Mynydd Carn y Cefn

Summit Height:  408.4m (LIDAR data)

Name:  Pt. 408.4m

OS 1:50,000 map:  161

Summit Grid Reference:  SO 18603 07087

Drop:  22.0m (LIDAR data)


The list of additions, reclassifications and deletions from the 400m Sub-Pedwar list since the 1st edition of the Y Pedwarau was published by Europeaklist are as follows:




400m SUB-PEDWAR ADDITIONS







Pt. 408.4m (LIDAR data) (SO 186 070) 22.0m drop













400m SUB-PEDWAR RECLASSIFICATIONS












400m SUB-PEDWAR DELETIONS










Myrddyn Phillips and Aled Williams (December 2016)

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