Mapping Mountains – Significant Height Revisions – 100m Twmpau and Y Trechol – The Dominant Hills of Wales

Woodlake Park (ST 343 997)

There has been a Significant Height Revision to a hill that is listed in the 100m Twmpau and Y Trechol – The Dominant Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Woodlake Park (AT 343 997)

The criteria for the two listings that this height revision applies to are:

100m Twmpau - Welsh hills at or above 100m and below 200m in height with 30m minimum drop, with an accompanying sub list entitled the 100m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 100m and below 200m 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.

Y Trechol – The Dominant Hills of Wales – Welsh P30 hills whose prominence equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height.  The list is authored by Myrddyn Phillips with the Introduction to the start of the Mapping Mountains publication of this list appearing on the 3^rd December 2015.

The name the hill is listed by is Woodlake Park and it is adjoined to the Cymoedd Gwent group of hills, which are situated in the eastern part of South Wales (Region C, Sub-Region C2), and it is positioned above the Llandegfedd Reservoir which is to its west, and has the town of Pont-y-pŵl (Pontypool) towards its west and Brynbuga (Usk) towards its east.

When the original Welsh 100m P30 list was published on Geoff Crowder’s v-g.me website this hill was listed with a 147m summit height, based on the spot height positioned at ST 340 994 that appears on the Ordnance Survey 1:50,000 Landranger map, with the 1:25,000 Explorer map having no spot height.

The details for this hill were re-evaluated when the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map became available online, and as this map gives a 149m spot height positioned at ST 34341 99786, the summit of this hill was relocated.

Extract from the Ordnance Survey Vector Map Local hosted on the Geograph website

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.

The height produced by LIDAR analysis is 150.7m positioned at ST 34335 99793,  this is not a substantial revision compared to some revised heights, but it does come within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

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.

Therefore, this hill’s new listed summit height is 150.7m and this was derived from LIDAR analysis, this is 1.7m higher than the previously listed summit height of 149m which was derived from the spot height that appears on the Ordnance Survey Vector Map Local hosted on the Geograph website. 

  

ills of Wales, and are reproduced below@

The full details for the hill are:

Group:  Cymoedd Gwent

Name:  Woodlake Park

OS 1:50,000 map:  171

Summit Height (New height):  150.7m (LIDAR)

Summit Grid Reference:  ST 34335 99793 (LIDAR)

Bwlch Height:  91.5m (LIDAR)

Bwlch Grid Reference:  ST 33405 01033 (LIDAR)

Drop:  59.3m (LIDAR)

Dominance:  39.31%

Myrddyn Phillips (August 2019)

Mapping Mountains – Summit Relocations – 100m Twmpau and Y Trechol – The Dominant Hills of Wales

Woodlake Park (ST 343 997)

There has been confirmation of a Summit Relocation to a hill that is listed in the 100m Twmpau and Y Trechol – The Dominant Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Woodlake Park (ST 343 997)

The criteria for the two listings that this summit relocation applies to are:

100m Twmpau - Welsh hills at or above 100m and below 200m in height with 30m minimum drop, with an accompanying sub list entitled the 100m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 100m and below 200m 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.

Y Trechol – The Dominant Hills of Wales – Welsh P30 hills whose prominence equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height.  The list is authored by Myrddyn Phillips with the Introduction to the start of the Mapping Mountains publication of this list appearing on the 3^rd December 2015.

The name the hill is listed by is Woodlake Park and it is adjoined to the Cymoedd Gwent group of hills, which are situated in the eastern part of South Wales (Region C, Sub-Region C2), and it is positioned above the Llandegfedd Reservoir which is to its west, and has the town of Pont-y-pŵl (Pontypool) towards its west and Brynbuga (Usk) towards its east.

When the original Welsh 100m P30 list was published on Geoff Crowder’s v-g.me website this hill was listed with a 147m summit height, based on the spot height positioned at ST 340 994 that appears on the Ordnance Survey 1:50,000 Landranger map, with the 1:25,000 Explorer map having no spot height.

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

Extract from the Ordnance Survey 1:25,000 Explorer map

The details for this hill were re-evaluated when the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map became available online, and as this map gives a 149m spot height positioned at ST 34341 99786, the summit of this hill was relocated.

Extract from the Ordnance Survey Vector Map Local hosted on the Geograph website

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.

The height produced by LIDAR analysis is 150.7m positioned at ST 34335 99793,  this confirms the summit relocation from its position originally given in the 100m P30 list of Geoff Crowder’s v-g.me website, and as such comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies to any listed hill whose summit meets the following criteria; where there are a number of potential summit positions within close proximity and the highest point is not where previously given, or a relocation of approximately 100 metres or more in distance from either the position of a map spot height or from where the summit of the hill was previously thought to exist, or when the summit of the hill is in a different field compared to where previously given, or when the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct.  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 relocations.

Therefore, the height produced by LIDAR analysis is 150.7m and this is positioned at ST 34335 99793, this position is close to where the 149m spot height appears on the Ordnance Survey Vector Map Local hosted on the Geograph website and is approximately 450 metres north north-east from where the originally listed summit adjoined to the 147m spot height is positioned.

The full details for the hill are:

Group:  Cymoedd Gwent

Name:  Woodlake Park

OS 1:50,000 map:  171

Summit Height:  150.7m (LIDAR)

Summit Grid Reference (new position):  ST 34335 99793 (LIDAR)

Bwlch Height:  91.5m (LIDAR)

Bwlch Grid Reference:  SO 33405 01033 (LIDAR)

Drop:  59.3m (LIDAR)

Dominance:  39.31% (LIDAR)

Myrddyn Phillips (August 2019)

Mapping Mountains – Significant Name Changes – 100m Twmpau and Y Trechol – The Dominant Hills of Wales

Woodlake Park (ST 343 997)

There has been a Significant Name Change to a hill that is listed in the 100m Twmpau and Y Trechol – The Dominant Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill confirmed by LIDAR analysis conducted by Myrddyn Phillips.

LIDAR image of Woodlake Park (ST 343 997)

The criteria for the two listings that this name change applies to are:

100m Twmpau - Welsh hills at or above 100m and below 200m in height with 30m minimum drop, with an accompanying sub list entitled the 100m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 100m and below 200m 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.

Y Trechol – The Dominant Hills of Wales – Welsh P30 hills whose prominence equal or exceed half that of their absolute height.  With the criteria for Lesser Dominant status being those additional Welsh P30 hills whose prominence is between one third and half that of their absolute height.  The list is authored by Myrddyn Phillips with the Introduction to the start of the Mapping Mountains publication of this list appearing on the 3^rd December 2015.

The hill is adjoined to the Cymoedd Gwent group of hills, which are situated in the eastern part of South Wales (Region C, Sub-Region C2), and it is positioned above the Llandegfedd Reservoir which is to its west, and has the town of Pont-y-pŵl (Pontypool) towards its west and Brynbuga (Usk) towards its east.

The hill originally appeared in the 100m P30 list on Geoff Crowder’s v-g.me website under a partly invented and transposed name of Pen Coed Canol, with an accompanying note stating; Name from wood to the East.

Pen Coed Canol

147m

ST341994

171

152

Name from wood to the East.

During my early hill listing I thought it appropriate to either invent a name for a hill, or use a name that appeared near to the summit of the hill on Ordnance Survey maps of the day.  My preference was to use farm names and put Pen, Bryn or Moel in front of them or as in this instance transpose the name of a near wood and prefix it with the word Pen.  This is not a practice that I now advocate as with time and inclination place-name data can be improved either by asking local people or by examining historic documents, through this form of research an appropriate name for the hill can usually be found.

Extract from the Ordnance Survey 1:25,000 Explorer map

The summit of this hill is situated in the grounds of a golf course and this is named on contemporary Ordnance Survey 1:25,000 maps as Woodlake Park, and for listing purpose this is an appropriate name to use for this hill.

Therefore, the name this hill is now listed by in the 100m Twmpau and Y Trechol – The Dominant Hills of Wales is Woodlake Park, and this was derived from the contemporary Ordnance Survey 1:25,000 Explorer map.

The full details for the hill are:

Group:  Cymoedd Gwent

Name:  Woodlake Park

Previously Listed Name:  Pen Coed Canol

 

OS 1:50,000 map:  171

Summit Height:  150.7m (LIDAR)

Summit Grid Reference:  ST 34335 99793 (LIDAR)

Bwlch Height:  91.5m (LIDAR)

Bwlch Grid Reference:  SO 33405 01033 (LIDAR)

 

Drop:  59.3m (LIDAR)

Dominance:  39.31% (LIDAR)

Myrddyn Phillips (August 2019)