Friday, 24 March 2017

Mapping Mountains – Hill Reclassifications – Y Pedwarau

Cwm Cynydd Bank (SO 053 724) - 400m Sub-Pedwar reclassified to Pedwar

There has been a reclassification to the listing of the Y Pedwarau with a 400m Sub-Pedwar being reclassified to Pedwar status due to analysis of LIDAR data by Aled Williams.  The 400m Sub-Pedwarau is one of five categories of sub hills that accompany the main Y Pedwarau list, with the criteria for 400m Sub-Pedwar status being all Welsh hills at or above 400m and below 500m in height with 20m or more and below 30m of drop, with the criteria for Pedwar status being all Welsh hills at or above 400m and below 500m in height with a minimum 30m of drop.

The hill is situated in the Pegwn Mawr group with its Cardinal Hill being Brondre Fawr Hill (SO 041 783) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B1), and is positioned between the small communities of Bwlch y Sarnau to the north-west and Abaty Cwm Hir (Abbey Cwmhir) to the south.

The summit of the hill is situated in conifer plantation but the hill can be accessed via forestry tracks from a number of directions as these encircle the upper part of the hill.  The forestry track towards the north-east and also the south-west of the summit gives access to a forest ride that passes within a few metres and to the east of the high point of the hill.

The name of the hill is Cwm Cynydd Bank (previously listed in Y Pedwarau as Pt. 444m, Cwmcynydd Bank) and prior to the analysis of LIDAR data and its subsequent listing as a Pedwar the hill had been listed as a 400m Sub-Pedwar with c 27m of drop based on the 444m spot height that appears at SO 05234 72506 on the Ordnance Survey 1:25,000 Explorer map and an estimated bwlch height of c 417m at SO 05783 72592.

As Aled was analysing other hills in the vicinity against LIDAR data, he did likewise with Cwm Cynydd BankLIDAR (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:

Cwm Cynydd Bank

Summit Height:  451.4m

Summit Grid Reference:  SO 05342 72437

Bwlch Height:  416.4m

Bwlch Grid Reference:  SO 05788 72576

Drop:  35.0m

Therefore, the 451.4m LIDAR data produced for the summit position at SO 05342 72437 and the 416.4m LIDAR data produced for the bwlch position at SO 05788 72576 gives this hill 35.0m of drop which is sufficient for its reclassification from a 400m Sub-Pedwar to a Pedwar.

The full details for the two hill are:

Cardinal Hill:  Brondre Fawr Hill  

Summit Height:  451.4m (LIDAR data)  

Name:  Cwm Cynydd Bank  

OS 1:50,000 map:  136, 147  

Summit Grid Reference:  SO 05342 72437  

Drop:  35.0m (LIDAR data)  

This now brings the overall total for Y Pedwarau to 445 hills with eight additions, and ten reclassifications to 400m Sub-Pedwar status since publication of the list by Europeaklist in May 2013.  The hill will be taken out of the 400m Sub-Pedwar list and added to the Pedwar list in forthcoming publications.  The list of Pedwar hills is available from the Haroldstreet website (January 2014) with all subsequent changes available via the Mapping Mountains site, with the list also having commenced publication on Mapping Mountains on the 30.01.17.

The list of additions and reclassifications from the Pedwar list since the 1st edition of the Y Pedwarau was published by Europeaklist are as follows:


Cwm Cynydd Bank (LIDAR data) (SO 053 724) 400m Sub-Pedwar reclassified to Pedwar with 35.0m drop


Myrddyn Phillips and Aled Williams (March 2017)

No comments: