Monday, 24 April 2017

Mapping Mountains – Hill Reclassifications – Yr Uchafion


Bwlan (SH 946 255) - Uchaf deletion

There has been a deletion from the listing of Yr Uchafion instigated from analysis of LIDAR data by Aled Williams.  Yr Uchafion is the draft title for a list of the Welsh 500m P15s that takes in all hills in Wales at or above 500m that have a minimum drop of 15m, the list is a joint compilation between Myrddyn Phillips and Aled Williams, with details relating to this list being published on the Mapping Mountains site in November 2015.

Accompanying the main Yr Uchafion list are three sub lists; 500m Sub-Uchaf, 490m Sub-Uchaf and the Double Sub-Uchaf categories, with the deletion of this hill affecting the main P15 Yr Uchafion list.

Prior to analysis of LIDAR data the hill was listed with 16m of drop based on a 51ft 6˝ (15.7m) basic levelling survey conducted my Myrddyn Phillips on the 10.05.05.  The hill is given a 528m summit spot height on Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps and has a 514m bwlch spot height on the Ordnance Survey enlarged mapping hosted on the Geograph website.  There are two options for where the critical bwlch of this hill is placed and between each is a 523m map heighted bump, the spot height on the enlarged map on the Geograph website appears on the eastern side of this bump and this is where the basic levelling survey started from, with the alternate westerly bwlch being visually dismissed as higher.  However, the basic levelling survey was conducted to the top of the 523m map heighted bump and not to the summit of the 528m map heighted Bwlan, this survey came to 10.7m, and 5m was then added to the drop value to compensate for the difference in map heights.  To ascertain a drop value for a hill using this method is not ideal and the accuracy and therefore this hill’s qualification as an Uchaf was always open to question.

The hill is situated in the Y Berwyn group of hills with its Cardinal Hill being Foel y Geifr (SH 918 246) and is placed in the Region of North Wales (Region A, Sub-Region A4), and is positioned between the stream valleys of the Afon Nadroedd to the north and the Afon Eiddew to the south, with Llyn Efyrnwy (Lake Vyrnwy) towards the hill’s south-east.

The hill is situated on open access land and can be accessed from the north either by following the boundary of a conifer plantation to cross the Nant Nadroedd Fawr before following a track to the hill’s bwlch, or it can be ascended starting lower in the valley from where the same track leaves the minor road and heads through the conifer plantation.  As the latter route through the conifer plantation is not on open access land permission to use this route should be sought.

The name of the hill is Bwlan and its deletion from Uchaf 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:


Bwlan

Summit Height:  526.1m (converted to OSGM15)

Summit Grid Reference:  SH 94690 25541

Bwlch Height:  512.6m (converted to OSGM15)

Bwlch Grid Reference:  SH 94180 25715

Drop:  13.6m


Therefore, the 526.1m (converted to OSGM15) LIDAR data produced for the summit position at SH 94690 25541 and the 512.6m (converted to OSGM15) LIDAR data produced for the bwlch position at SH 94180 25715 gives this hill 13.55m of drop which is insufficient for its retention as an Uchaf and also for it to be reclassified as a 500m Sub-Uchaf.


The full details for the hill are:

Cardinal Hill:  Foel y Geifr

Summit Height:  526.1m (converted to OSGM15) (LIDAR data)

Name:  Bwlan

OS 1:50,000 map:  125

Summit Grid Reference:  SH 94690 25541 
  
Drop:  13.6m (converted to OSGM15) (LIDAR data)


The overall total for Yr Uchafion / The Welsh 500m P15s is now 63o hills with the total for the 500m Sub-Uchaf category remaining at 25.

For the additions, reclassifications and deletions to Yr Uchafion / The Welsh 500m P15s reported on Mapping Mountains please consult the following Change Registers:











Myrddyn Phillips and Aled Williams (April 2017)


Sunday, 23 April 2017

Mapping Mountains – Hill Reclassifications – Y Pedwarau


Pen y Bryn Du (SJ 166 347) - 400m Sub-Pedwar deletion

There has been a deletion 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 alteration affecting 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 listed with 20m of drop based on the 455m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and the 435m bwlch spot height that appears on the Ordnance Survey 1:25,000 Explorer map.

The hill is situated in the Y Berwyn group of hills with its Cardinal Hill being Moel Fferna (SJ 116 397) and is placed in the Region of North Wales (Region A, Sub-Region A4), and is positioned with the small communities of Llanarmon Dyffryn Ceiriog to its south south-west and Pandy to its east north-east.

If wanting to visit the hill permission to do so should be sought as it is not on open access land.  It is positioned between two stream valleys to its west and east, both have rights of access on tracks that head to the north of the summit and would give access to the hill and its summit.

The name of the hill is Pen y Bryn Du and its deletion from 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:


Pen y Bryn Du

Summit Height:  455.3m

Summit Grid Reference:  SJ 16699 34722

Bwlch Height:  435.9m

Bwlch Grid Reference:  SJ 16535 35083

Drop:  19.4m


Therefore, the 455.3m LIDAR data produced for the summit position at SJ 16699 34722 and the 435.9m LIDAR data produced for the bwlch position at SJ 16535 35083 gives this hill 19.4m of drop which is insufficient for its retention as a 400m Sub-Pedwar.


The full details for the hill are:

Cardinal Hill:  Moel Fferna

Summit Height:  455.3m (LIDAR data)

Name:  Pen y Bryn Du

OS 1:50,000 map:  125

Summit Grid Reference:  SJ 16699 34722

Drop:  19.4m (LIDAR data)


The overall total for Y Pedwarau remains at 445 hills with eight additions, and ten 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 216 with 18 hills being added and 15 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:











Myrddyn Phillips and Aled Williams (April 2017)



Saturday, 22 April 2017

Mapping Mountains – Hill Reclassifications – Yr Uchafion


Pt. 522.0m (SJ 136 363) - 500m Sub-Uchaf deletion

There has been a deletion from the listing of Yr Uchafion instigated from analysis of LIDAR data by Aled Williams.  Yr Uchafion is the draft title for a list of the Welsh 500m P15s that takes in all hills in Wales at or above 500m that have a minimum drop of 15m, the list is a joint compilation between Myrddyn Phillips and Aled Williams, with details relating to this list being published on the Mapping Mountains site in November 2015.

Accompanying the main Yr Uchafion list are three sub lists; 500m Sub-Uchaf, 490m Sub-Uchaf and the Double Sub-Uchaf categories, with the deletion of this hill affecting the 500m Sub-Uchaf classification, with the criteria for qualification to this sub category being all Welsh hills at or above 500m in height that have 14m or more and below 15m of drop.

Prior to analysis of LIDAR data the hill was listed with 14m of drop based on the 522m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps and the 508m bwlch spot height that appears on the Ordnance Survey 1:25,000 Explorer map.

The hill is situated in the Y Berwyn group of hills with its Cardinal Hill being Moel Fferna (SJ 116 397) and is placed in the Region of North Wales (Region A, Sub-Region A4), and is positioned with the small communities of Llanarmon Dyffryn Ceiriog to its south south-east and Pandy to its east.

The hill is situated on open access land and can be accessed from the south or north-east, with public footpaths making their way up to higher ground from the stream valleys containing the Afon Ceiriog and the Afon Teirw respectively.

Although a number of local names for the hill exist it is being catalogued by the point (Pt. 522.0m) notation and its deletion from the 500m Sub-Uchaf category 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. 522.0m

Summit Height:  522.0m (converted to OSGM15)

Summit Grid Reference:  SJ 13615 36369

Bwlch Height:  508.2m (converted to OSGM15)

Bwlch Grid Reference:  SJ 13888 36062

Drop:  13.8m


Therefore, the 522.0m (converted to OSGM15) LIDAR data produced for the summit position at SJ 13615 36369 and the 508.2m (converted to OSGM15) LIDAR data produced for the bwlch position at SJ 13888 36062 gives this hill 13.8m of drop which is insufficient for its retention as a 500m Sub-Uchaf.


The full details for the hill are:

Cardinal Hill:  Craig Berwyn

Summit Height:  522.0m (converted to OSGM15) (LIDAR data)

Name:  Pt. 522.0m

OS 1:50,000 map:  125

Summit Grid Reference:  SJ 13615 36369
   
Drop:  13.8m (converted to OSGM15) (LIDAR data)


The overall total for Yr Uchafion / The Welsh 500m P15s remains at 631 hills with the total for the 500m Sub-Uchaf category now being 25

For the additions, reclassifications and deletions to Yr Uchafion / The Welsh 500m P15s reported on Mapping Mountains please consult the following Change Registers:











Myrddyn Phillips and Aled Williams (April 2017)



Friday, 21 April 2017

Mapping Mountains – Significant Name Changes – Y Pedwarau and Y Trechol – The Dominant Hills of Wales


Cefn Digoll (SJ 264 058)

This is the seventy second post under the heading of Significant Name Changes, and the following details are in respect of a hill that was surveyed with the Trimble GeoXH 6000 on the 24th and 28th March 2017.

The hill is a part of the Cefn Digoll range, which is situated in the north-eastern part of Mid and West Wales (Region B, Sub-Region B1), and is positioned above the A 483 and the village of Trewern to its north and the town of Y Trallwng (Welshpool) to its west north-west.  

The summit of Cefn Digoll

The hill appeared in the 300m P30 list on Geoff Crowder’s v-g.me website under the name Beacon Ring, this is the name given to the summit area of the hill in English, with its Welsh counterpart being Caer Digoll.  The listing this hill is now a part of is named the Y Pedwarau (Welsh hills at or above 400m and below 500m in height with 30m minimum drop and co-authored; Myrddyn Phillips and Aled Williams ) and Y Trechol – The Dominant Hills of Wales (Welsh P30 hills whose prominence equal or exceed half that of their absolute height and authored; Myrddyn Phillips) and its height, drop and dominance was confirmed by a survey with the Trimble GeoXH 6000. 

Beacon Ring  408m  SJ265058  126216  Marilyn. Clem/Yeaman. Trig pillar marked on map.


During my early hill listing I did not lay emphasis on prioritising a name for a hill over that for its summit, and therefore on occasion I used a summit name in preference to that of the hill name, and the use of Beacon Ring is a case in point as the hill is known in English as the Long Mountain.  This practice can be appropriate if the summit name is prioritised locally, otherwise for listing purposes it is customary to prioritise the hill name in preference to that of its summit.

Also during my early hill listing I thought it sufficient to use English or anglicised names for hills even if a Welsh name existed, this in the main is not a practice that I now advocate, especially if the Welsh name has historical evidence of use, and as the English names for this hill and its summit have Welsh counterparts, these being Cefn Digoll and Caer Digoll respectively, the hill name of Cefn Digoll is being used. 

Therefore the name this hill is now listed by in the Y Pedwarau and Y Trechol – The Dominant Hills of Wales is Cefn Digoll, as this is the Welsh name for the hill.


The full details for the hill are:


Group:  Cefn Digoll

Name:  Cefn Digoll

Previously Listed Name:  Beacon Ring 

Summit Height:  408.3m (converted to OSGM15)

OS 1:50,000 map:  126

Summit Grid Reference:  SJ 26476 05824  

Drop:  305.0m (converted to OSGM15)





Myrddyn Phillips and Aled Williams (April 2017)







Wednesday, 19 April 2017

Mapping Mountains – Hill Reclassifications – Y Trichant


Twyn y Ffald (SN 852 160) - Sub-Trichant addition

There has been an addition to the listing of Y Trichant, this is the draft title for the hills in the 300m height band of the Twmpau (thirty welsh metre prominences and upward) due to analysis of LIDAR data by Aled Williams.  With the criteria for Y Trichant being all Welsh hills 300m or more and below 400m in height with 30m minimum drop.

Accompanying the main Y Trichant list is a sub list known as the Sub-Trichant.  With the criteria for Sub-Tricahnt qualification being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.

Prior to analysis of LIDAR data the hill was catalogued with c 19m of drop which was insufficient for it to be listed as a Sub-Trichant, this drop value was based on an estimated summit height of c 362m and an estimated bwlch height of c 343m, with the latter taken to land that forms a part of a disused quarry, and therefore the old connecting bwlch of this hill no longer exists.

The hill is adjoined to the Fforest Fawr group of hills with its Cardinal Hill being Fan Gyhirych (SN 880 191) and is placed in the Region of South Wales (Region C, Sub-Region C2), and is situated with the small community of Glyntawe to its north-west.

The hill can be accessed from the end of a minor road at Penwyllt and can be combined with higher hills to its east.  However, the summit of this hill is not on open access land and it is positioned on the periphery of a disused quarry, therefore permission should be sought to visit, but with open access land relatively close towards the north-east, common sense should prevail and if wanting to visit the summit there is likely to be no objection to doing so.

The name of the hill is Twyn y Ffald and its addition to Sub-Trichant status is due to 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:


Twyn y Ffald

Summit Height:  368.7m

Summit Grid Reference:  SN 85227 16034

Bwlch Height:  342.8m

Bwlch Grid Reference:  SN 85541 16188

Drop:  25.9m


Therefore, the 368.7m LIDAR data produced for the summit position at SN 85227 16034 and the 342.8m LIDAR data produced for the bwlch position at SN 85541 16188 gives this hill 25.9m of drop, which is sufficient for its inclusion as a Sub-Trichant, therefore this hill is included in this sub category and the total in the Y Trichant and the Twmpau which will be updated accordingly.


The full details for the hill are:

Cardinal Hill:  Fan Gyhirych

Summit Height:  368.7m (LIDAR data)

Name:  Twyn y Ffald

OS 1:50,000 map:  160

Summit Grid Reference:  SN 85227 16034
   
Drop:  25.9m (LIDAR data)



My thanks to Aled Williams for sending the details of this hill to me.



Myrddyn Phillips (April 2017)

Tuesday, 18 April 2017

Mapping Mountains – Hill Reclassifications – Y Pedwarau


Pt. 458.5m (SN 982 116) - 400m Sub-Pedwar deletion

There has been an alteration to the listing of Y Pedwarau due to analysis of LIDAR data by Aled Williams.  Y Pedwarau is the title for the co-authored listing of the 400m hills of Wales, with the criteria for this list being all Welsh hills at or above 400m and below 500m in height with a minimum 30m of drop.

Accompanying the main Y Pedwarau list are five categories of sub hills, with this alteration affecting 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 listed with 20m of drop based on the 458m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and the 438m bwlch spot height that appears on the Ordnance Survey enlarged mapping hosted on the Geograph website.

The hill is situated in the Fforest Fawr group of hills with its Cardinal Hill being Fan Fawr (SN 969 193) and is placed in the Region of South Wales (Region C, Sub-Region C2).  The hill is positioned above the small communities of Penderyn to its south-west and Llwyn Onn to its east. 

The hill is situated on open access land and can be easily accessed from either its north north-west from the A 4059 road and also taking in the 485m map heighted Pedwar of Cadair Fawr (SN 977 123), or it can be accessed from its south-east from the convenience of a narrow minor road that reaches over 400m in height.

As the authors do not know an individual name for the hill either from local and / or historical research we are following the point (Pt. 458.5m) notation and its deletion from 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. 458.5m

Summit Height:  458.5m

Summit Grid Reference:  SN 98267 11645

Bwlch Height:  438.9m

Bwlch Grid Reference:  SN 98245 11829

Drop:  19.6m


Therefore, the 458.5m LIDAR data produced for the summit position at SN 98267 11645 and the 438.9m LIDAR data produced for the bwlch position at SN 98245 11829 gives this hill 19.6m of drop which is insufficient for its retention as a 400m Sub-Pedwar.


The full details for the hill are:

Cardinal Hill:  Fan Fawr

Summit Height:  458.5m (LIDAR data)

Name:  Pt. 458.5m

OS 1:50,000 map:  160

Summit Grid Reference:  SN 98267 11645

Drop:  19.6m (LIDAR data)


The overall total for Y Pedwarau remains at 445 hills with eight additions, and ten 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 217 with 18 hills being added and 14 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:











Myrddyn Phillips and Aled Williams (April 2017)