Mapping Mountains – Hill Reclassifications – 30-99m Twmpau

 

Whiteford Burrows (SS 448 964) – Double Sub-Twmpau addition 

There has been an addition to the list of Double Sub-Twmpau adjoined to the 30-99m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis initially conducted by Aled Williams and subsequently by Myrddyn Phillips. 

LIDAR image of Whiteford Burrows (SS 448 964)

The criteria for the list that this addition applies to are:

30-99m Twmpau - Welsh hills at or above 30m and below 100m in height with 30m minimum drop, this height band of hills has two accompanying sub lists, the first of which is entitled the 30-99m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 30m and below 100m in height with 20m or more and below 30m of drop, and the second sub category is entitled the Double Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 20m and below 30m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 30-99m Twmpau by Myrddyn Phillips

The name the hill is listed by is Whiteford Burrows and it is adjoined to the Gŵyr group of hills, which are situated in the western part of South Wales (Region C, Sub-Region C1), and it is positioned overlooking Whiteford Point and the coast, and has the small community of Llanmadog towards the south. 

When the original 30-99m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was not included in the Hills to be surveyed sub list, as it was considered not to meet the criteria then used for this sub category. 

Prior to LIDAR analysis this hill was not catalogued as the uppermost contour given it on the Ordnance Survey 1:25,000 Explorer map is 5m, whilst the Ordnance Survey 1:50,000 Landranger map has no contours. 

Extract from the Ordnance Survey 1:50,000 Landranger map

However, it was not until LIDAR became available that the details for this hill could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.  

Therefore, the addition of this hill to Double Sub-Twmpau status is due to LIDAR analysis, resulting in a 29.6m summit height and a 9.2m bwlch height, with these values giving this hill 20.4m of drop, which is sufficient for it to be classified as a Double Sub-Twmpau. 

 

The full details for the hill are: 

Group:  Gŵyr

Name:  Whiteford Burrows

OS 1:50,000 map:  159

Summit Height:  29.6m (LIDAR)

Summit Grid Reference:  SS 44870 96422 (hand-held GPS)

Bwlch Height:  9.2m (LIDAR)

Bwlch Grid Reference:  SS 44631 95701 (LIDAR)   

Drop:  20.4m (LIDAR)

 

Myrddyn Phillips (August 2021)

 

 

 

 

 

 

Mapping Mountains – Significant Height Revisions – Y Pellennig – The Remotest Hills of Wales

Whiteford Burrows (SS 448 964)

There has been a Significant Height Revision to a hill that now appears in the Y Pellennig – The Remotest Hills of Wales list due to LIDAR analysis initially conducted by Aled Williams and subsequently by Myrddyn Phillips.

LIDAR image of Whiteford Burrows

The criteria for the list that this significant height revision applies to are:

Y Pellennig – The Remotest Hills of Wales - Welsh hills whose summit is at least 2.5km from the nearest paved public road and the hill has a minimum 15m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and is available as a downloadable e-booklet or print-booklet version on Mapping Mountains Publications with the up-to-date master list available on the Mapping Mountains site in Google Doc format.

The name of the hill is Whiteford Burrows and it is adjoined to the Gŵyr group of hills, which are situated in the western part of South Wales (Region C, Sub-Region C1), and it is positioned overlooking Whiteford Point and the coast, and has the small community of Llanmadog towards the south.

As the hill is a part of designated open access land it can be approached from any direction, for those wishing to visit the Wales Coast Path approaches the hill from the south and follows land close to the coast and heads toward Whiteford Point, and the summit of the hill is only a short distance from this long distance path.

Prior to LIDAR analysis this hill was not catalogued as the uppermost contour given it on the Ordnance Survey 1:25,000 Explorer map is 5m, whilst the Ordnance Survey 1:50,000 Landranger map has no contours.  LIDAR gives a summit height of 28.3m, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

Extract from the Ordnance Survey 1:50,000 Landranger map

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.  As heights on different scaled Ordnance Survey maps are not consistent the height given on the 1:25,000 Explorer map is being prioritised in favour of the 1:50,000 Landranger map for detailing these revisions.

Therefore, this hill’s new summit height is 29.6m and this was produced by LIDAR analysis, this is 24.6m higher than the uppermost 5m contour on the Ordnance Survey 1:25,000 Explorer map, however this new height is in accordance with the 5m contouring on OS Maps. 

 

LIDAR summit image of Whiteford Burrows

ills of Wales, and are reproduced below@

The full details for the hill are:

Group:  Gŵyr

Name:  Whiteford Burrows

OS 1:50,000 map:  159

Summit Height (New height):  29.6m (LIDAR)

Summit Grid Reference:  SS 44870 96422 (hand-held GPS)

Bwlch Height:  9.2m (LIDAR)

Bwlch Grid Reference:  SS 44631 95701 (LIDAR) 

  

Drop:  20.4m (LIDAR)

Remoteness:  2.925km

Myrddyn Phillips and Aled Williams (December 2018)

Mapping Mountains – Hill Reclassifications – Y Pellennig – The Remotest Hills of Wales

Whiteford Burrows (SS 448 964) – Pellennig addition

There has been an addition to the listing of Y Pellennig – The Remotest Hills of Wales due to LIDAR analysis initially conducted by Aled Williams and subsequently by Myrddyn Phillips.

LIDAR image of Whiteford Burrows

The criteria for the list that this addition applies to are:

Y Pellennig – The Remotest Hills of Wales - Welsh hills whose summit is at least 2.5km from the nearest paved public road and the hill has a minimum 15m of drop, the list is a joint compilation between Myrddyn Phillips and Aled Williams and is available as a downloadable e-booklet or print-booklet version on Mapping Mountains Publications with the up-to-date master list available on the Mapping Mountains site in Google Doc format.

The name of the hill is Whiteford Burrows and prior to LIDAR analysis this hill was not catalogued as the uppermost contour given it on the Ordnance Survey 1:25,000 Explorer map is 5m, whilst the Ordnance Survey 1:50,000 Landranger map has no contours.

Extract from the Ordnance Survey 1:50,000 Landranger map

Whiteford Burrows is adjoined to the Gŵyr group of hills, which are situated in the western part of South Wales (Region C, Sub-Region C1), and it is positioned overlooking Whiteford Point and the coast, and has the small community of Llanmadog towards the south.

As the hill is a part of designated open access land it can be approached from any direction, for those wishing to visit the Wales Coast Path approaches the hill from the south and follows land close to the coast and heads toward Whiteford Point, and the summit of the hill is only a short distance from this long distance path.

The addition of this hill to Pellennig status is due to LIDAR analysis conducted by Myrddyn Phillips.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales. 

The 2m DSM LIDAR analysis gives the hill the following details:

Name:  Whiteford Burrows

Summit Height:  29.6m

Summit Grid Reference:  SS 44870 96422

Bwlch Height:  9.2m

Bwlch Grid Reference:  SS 44631 95701

Drop:  20.4m

Therefore, the 29.6m LIDAR analysis for the summit position at SS 44870 96422 and the 9.2m LIDAR analysis for the bwlch position at SS 44631 95701 gives this hill 20.4m of drop, and with the nearest paved public road to its summit being at SS 43885 93665, it gives this hill 2.925km of remoteness which when coupled with this hill’s drop value is sufficient for Pellennig status.

LIDAR summit image of Whiteford Burrows

The full details for the hill are:

Group:  Gŵyr

Name:  Whiteford Burrows

OS 1:50,000 map:  159

Summit Height:  29.6m (LIDAR)

Summit Grid Reference:  SS 44870 96422 (LIDAR)

Bwlch Height:  9.2m (LIDAR)

Bwlch Grid Reference:  SS 44631 95701 (LIDAR) 

  

Drop:  20.4m (LIDAR)

Remoteness:  2.925km

For the additions and deletions to Y Pellennig – The Remotest Hills of Wales reported on Mapping Mountains please consult the following Change Register:

Y Pellennig – The Remotest Hills of Wales

Myrddyn Phillips and Aled Williams (December 2018)