Friday 29 March 2024

Mapping Mountains – Significant Height Revisions – 200m Twmpau


Comin Gwauncaegurwen (SN 721 131) 

There has been a Significant Height Revision to a hill that is listed in the 200m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail produced by JoeNuttall in his surface analysis programme, with subsequent LIDAR analysis conducted by the DoBIH team and independently by Myrddyn Phillips. 

LIDAR image of Comin Gwauncaegurwen (SN 721 131)

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

200m Twmpau – Welsh hills at or above 200m and below 300m in height that have 30m minimum drop, with an accompanying sub list entitled the 200m Sub-Twmpau, with the criteria for this sub category being all Welsh hills at or above 200m and below 300m 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. 

200m Twmpau by Myrddyn Phillips

The name the hill is listed by is Comin Gwauncaegurwen and this was derived from the Tithe map with the language protocol also used, and it is adjoined to the Mynydd Du group of hills, which are situated in the southern part of South Wales (Region B, Sub-Region B5), and it is positioned with the A4068 road to its north, the A4069 road to its west and a minor road to its south-west, and has the village of Brynaman towards the north-west.

When the original 200m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was not included in the main P30 list or the accompanying Hills to be surveyed sub list, as with no significant contours of note on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map it was difficult to judge whether any hill of note existed. 

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

Since the original publication of the Welsh P30 lists on Geoff Crowder’s v-g.me website there have been a number of maps made available online.  Some of these are historic such as the series of Six-Inch maps on the National Library of Scotland website.  Whilst others were digitally updated such as the Ordnance Survey Vector Map Local that was hosted on the Geograph website and which was entitled the Interactive Coverage Map, whilst others are current and digitally updated such as the interactive mapping on the Magic Maps and WalkLakes websites. 

Extract from the interactive mapping hosted on the WalkLakes website

One of the mapping resources now available online is the WalkLakes website which hosts an interactive map originated from the Ordnance Survey Open Data programme.  This map has many spot heights not on other publicly available maps and a 258m spot height is given on the summit area of this hill.  Latterly the contemporary Ordnance Survey 1:25,000 Explorer map now has an uppermost 250m contour for this hill. 

Extract from the contemporary online Ordnance Survey 1:25,000 Explorer 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. 

LIDAR summit image of Comin Gwauncaegurwen (SN 721 131)

LIDAR analysis gives the highest ground on this hill that could now be deemed natural as 258.4m positioned at SN 72135 13154, and when compared to detail on contemporary Ordnance Survey maps when the Welsh P30 lists were originated this comes 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, the new listed summit height of this hill is 258.4m and this was derived from LIDAR analysis, this is 34.4m higher than the uppermost 220m contour on the old Ordnance Survey 1:50,000 Landranger and 1:25,000 Outdoor Leisure map and 8.4m higher than the uppermost 250m contour that appears online on the contemporary Ordnance Survey 1:25,000 Explorer map.

 

ills of Wales, and are reproduced below@

The full details for the hill are:

Group:  Mynydd Du 

Name:  Comin Gwauncaegurwen 

OS 1:50,000 map:  160

Summit Height (New Height):  258.4m (LIDAR) 

Summit Grid Reference:  SN 72135 13154 (LIDAR) 

Bwlch Height:  218.5m (LIDAR) 

Bwlch Grid Reference:  SN 72505 12523 (LIDAR) 

Drop:  39.9m (LIDAR) 

 

Myrddyn Phillips (March 2024)

  

Thursday 28 March 2024

Mapping Mountains – Significant Name Changes – The Fours – The 400m Hills of England


Three Barrows (SX 652 626) 

There has been a Significant Name Change that is retrospective to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Three Barrows (SX 652 626)

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

The FoursThe 400m Hills of England.  English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main list are three categories of sub hills, these are the 400m Sub-Fours, the 390m Sub-Fours and the 390m Double Sub-Fours.  The list is co-authored by Myrddyn Phillips and Aled Williams and the 2nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The hill is adjoined to the Ryder’s Hill group of hills, which are situated in Dartmoor in the south-west of the country, and it is positioned with a series of minor roads to its south-west and south-east, and the B3213 road and the A38 road to its south, and has the town of Ivybridge towards the south. 

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

When the listing that is now known as The Fours – The 400m Hills of England was originally compiled by Myrddyn Phillips this hill appeared under the name of Ugborough Moor; which is a prominent name that appears close to its summit on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and this was also the name the hill appeared as when the list was uploaded to the RHB Yahoo group file database. 

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

However, the listed name of this hill was amended and given as Three Barrows when the 1st edition of the The Fours now co-authored by Myrddyn Phillips and Aled Williams was published by Europeaklist in December 2013 and when the 2nd edition of The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018.

Therefore, the name this hill is now listed by in The Fours - The 400m Hills of England is Three Barrows and this was derived from a variety of Ordnance Survey maps, including the contemporary Ordnance Survey 1:25,000 Explorer map.                                                                                 


The full details for the hill are:

Group:  Ryder’s Hill

Name:  Three Barrows

Previously Listed Name:  Ugborough Moor 

OS 1:50,000 map:  202

Summit Height:  461.3m (LIDAR)

Summit Grid Reference:  SX 65286 62610 (LIDAR)

Col Height:  426.7m (LIDAR)

Col Grid Reference:  SX 65153 63316 (LIDAR)

Drop:  34.6m (LIDAR)

 

Myrddyn Phillips and Aled Williams (March 2024)

 

 

 

  

Wednesday 27 March 2024

Mapping Mountains – Hill Reclassifications – 100m Twmpau


Pt. 152.6m (SN 747 277) – 100m Sub-Twmpau addition

There has been confirmation of an addition to the list of 100m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Pt. 152.6m (SN 747 277)

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

100m Twmpau – Welsh hills at or above 100m and below 200m in height that have 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. 

100m Twmpau by Myrddyn Phillips

The hill is being listed by the point (Pt. 152.6m) notation as an appropriate name for it either through local enquiry and/or historic research has not been found by the author, and it is adjoined to the Mynydd Du group of hills, which are situated in the southern part of South Wales (Region B, Sub-Region B5), and it is positioned encircled by minor roads, with the A4069 road farther to its west, and has the village of Llangadog towards the west.

When the original 100m 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.

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-assessed and it was listed with 21m of drop, based on the 153m summit spot height and the 132m bwlch spot height that appear on the contemporary Ordnance Survey 1:25,000 Explorer map. 

Extract from the Ordnance Survey 1:25,000 Explorer 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 confirmation of the addition of this hill to 100m Sub-Twmpau status is due to LIDAR analysis, resulting in a 152.6m summit height and a 132.5m bwlch height, with these values giving this hill 20.1m of drop, which is sufficient for it to be classified as a 100m Sub-Twmpau. 

 

The full details for the hill are: 

Group:  Mynydd Du 

Name:  Pt. 152.6m 

OS 1:50,000 map:  146, 160

Summit Height:  152.6m (LIDAR) 

Summit Grid Reference:  SN 74733 27758 (LIDAR) 

Bwlch Height:  132.5m (LIDAR) 

Bwlch Grid Reference:  SN 74874 27534 (LIDAR) 

Drop:  20.1m (LIDAR) 

 

Myrddyn Phillips (March 2024)

 

 

 

 

 

  

Tuesday 26 March 2024

Mapping Mountains – Summit Relocations – Y Trichant – The 300m Hills of Wales


Mynydd y Garth (SN 711 081) 

There has been a Summit Relocation to a hill that is listed in the Y Trichant – The 300m Hills of Wales, with the summit height, bwlch height and their locations, the drop and status of the hill derived from LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Mynydd y Garth (SN 711 081)

The criteria for the list that this summit relocation applies to are:Y Trichant – The 300m Hills of Wales – Welsh hills at or above 300m and below 400m in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant, with the criteria for this sub category being all Welsh hills at or above 300m and below 400m in height with 20m or more and below 30m of drop.  The list is authored by Myrddyn Phillips with the Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13th May 2017, and the Introduction to the Mapping Mountains publication of the list appearing on the 1st January 2022. 

Y Trichant - The 300m Hills of Wales by Myrddyn Phillips

The name the hill is listed by is Mynydd y Garth and it is adjoined to the Mynydd Du group of hills, which are situated in the southern part of South Wales (Region B, Sub-Region B5), and it is positioned with a minor road to its north and east, and the A474 road to its west, and has the town of Pontardawe towards the south. 

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

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website, this hill was included in the accompanying sub list with a 321m summit height, based on the spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and which is positioned at SN 71293 08388. 

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

LIDAR summit image of Mynydd y Garth (SN 711 081)

LIDAR analysis gives the highest ground on this hill as 321.8m positioned at SN 71149 08116, and this in relation to the previously listed summit position which LIDAR analysis gives as 321.0m in height and positioned at SN 71306 08392 comes within the parameters of the Summit Relocations used within this page heading, these parameters are:

The term Summit Relocations applies when the high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, when natural ground or the natural and intact summit of a hill is confirmed compared to a higher point such as a raised field boundary or covered reservoir that is considered a relatively recent man-made construct, 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.

Therefore, the summit height produced by LIDAR analysis is 321.8m and this is positioned at SN 71149 08116, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 280 metres south south-westward from where the previously listed summit is positioned. 

 

The full details for the hill are:

Group:  Mynydd Du 

Name:  Mynydd y Garth 

OS 1:50,000 map:  160

Summit Height:  321.8m (LIDAR)                                                           

Summit Grid Reference (New Position):  SN 71149 08116 (LIDAR) 

Bwlch Height:  296.1m (LIDAR) 

Bwlch Grid Reference:  SN 71524 08760 (LIDAR) 

Drop:  25.7m (LIDAR) 

 

Myrddyn Phillips (March 2024)

 

 

 

 

  

Monday 25 March 2024

BBC Cymru Fyw - Welsh Highlands - Uchafion Cymru

 

BBC Cymru Fyw Article 

BBC Cymru Fyw recently published an article on my completion of the 630 hills that make up the listing of the Welsh Highlands – Uchafion Cymru.  The original article and a link to it on the BBC Cymru Fyw website appear below.

 

 

Y person cyntaf i ddringo 630 mynydd uchaf Cymru

 

Ar gopa Esgair Garthen - y mynydd olaf o'r 630

Ei gariad am fynyddoedd sy' wedi ysbarduno Myrddyn Phillips i ddringo 630 o'r mynyddoedd uchaf yng Nghymru - y person cyntaf i wneud hynny erioed.


Mae wedi cymryd 20 mlynedd i'r mapiwr mynyddoedd o'r Trallwng ddringo pob un o Uchafion Cymru, sef pob mynydd sy'n uwch na 500 metr.


Mae Myrddyn yn dogfennu pob un ar ei flog Mapping Mountains ac mi wnaeth gwblhau'r her drwy ddringo Esgair Garthen yng Nghwm Elan ddiwedd 2023.


 

Yr Wyddfa


Roedd y profiad yn 'anhygoel' yn ôl Myrddyn, wnaeth gychwyn ei ddiddordeb mewn mynydda yn 1988 pan yn 27 oed: "Mae'n rhywbeth o'n i'n awyddus i'w wneud pan gafodd y rhestr Uchafion Cymru ei lunio'n wreiddiol ac mae hynny'n mynd yn ôl bron i 20 mlynedd.

"Mae wedi bod yn broses araf gydag un neu ddau o anhawsterau. Pan ddaeth Covid i mewn gyda'r holl gyfyngiadau roedd y momentwm wedi mynd. Mae wedi cymryd amser i ddal fyny wedyn.

"Yr amrywiaeth sy'n gwneud mynyddoedd Cymru mor arbennig. Mae'n syfrdanol.

"Nid yw Cymru yn wlad fawr ond hyd yn oed petaech yn cerdded y bryniau bob penwythnos fyddech chi ddim yn gallu gwneud y bryniau i gyd. Mae o hyd bryn arall i ymweld ag ef."

 

Myrddyn ar gopa mynydd Fan y Big yn y Bannau Brycheiniog


Mae'n defnyddio peiriant o'r enw Trimble GeoX 6000 i arolygu a mesur ein huchelfannau gan nodi'r canfyddiadau ar ei wefan ac mae hefyd yn y broses o ysgrifennu llyfr am yr Uchafion gyda'i gydweithiwr Aled Williams o Borthmadog.

Cydweithiodd y ddau ar y rhestr wreiddiol o Uchafion Cymru, fel mae Myrddyn yn ei esbonio: "Fe wnes i lunio'r rhestr wreiddiol gydag Aled - ni sy'n gyfrifol am ddadansoddi'r rhestr ac ychwanegu bryniau newydd ati os ydyn nhw'n gymwys (uwch na 500m gyda 15m o ostyngiad o leiaf) a thynnu bryniau eraill ohoni os ydyn ni'n darganfod nad ydyn nhw.

 

Foel Meirch


"Os ewch chi nôl 10 mlynedd roeddem ni'n ddibynnol iawn ar fapiau arolwg ordnans. Dyddiau hyn mae nifer o syrfewyr annibynnol yn cynhyrchu uchder cywir ond mae hefyd rhywbeth o'r enw Lider sy' wedi'i gynhyrchu gan Asiantaeth yr Amgylchedd a gallwch gael mynediad at y data ar-lein ac mae hynny'n hynod gywir.

"Felly mae bron pob mynydd ar draws Cymru wedi ei gynnwys."

 

Moel y Llyn


Mae Myrddyn, sy'n 63 oed ac wedi bod yn dringo'r Uchafion ar ddydd Sadwrn fel arfer, hefyd yn ymddiddori yn enwau'r mynyddoedd: "Un o'r elfennau rydyn ni'n canolbwyntio arno (yn y llyfrmae'n ei ysgrifennu) yw ymchwil i enwau lleoedd. Cysylltais â dros 500 o ffermwyr, bugeiliaid, tirfeddianwyr ac academyddion a haneswyr lleol i holi am enwau bryniau.

"Pan edrychwch chi ar yr OS nawr, nid oes gan bob bryn enw ar fap OS yn enwedig wrth i chi gyrraedd y bryniau llai amlwg.

"O'n i'n gwybod mai'r gymuned orau i'w holi fyddai'r ffermwyr lleol. Dechreuais ddod ar draws enwau gwych nad oedd erioed wedi ymddangos ar fap OS. Roedd yn anhygoel. Mae Aled wedi ymchwilio hefyd ac mae gennym ni wybodaeth a diweddariadau ar y blog."

 

Rhinog Fawr


Wedi dringo dros 600 o fynyddoedd y wlad, oes gan Myrddyn ffefryn?

Meddai: "Mae dwy o'r cadwyni o fynyddoedd y byddwn i'n dewis yn syfrdanol yn eu ffordd eu hunain - un yw'r Rhinogydd sy' rhwng Abermawr ac Abermaw ac mae rhan ogleddol y grŵp bryniau hwnnw'n syfrdanol - yn wyllt a garw.

"Yr ardal arall y byddwn i'n sôn amdani yw'r ardal o fryniau wnes i orffen arni - yr Elenydd sy' i'r gorllewin o ardal Rhaeadr. Maent yn fryniau agored heb lawer o ffensys ac ar y cyfan yn laswelltir. Mae'r ymdeimlad o dawelwch os ydych chi yno ar ddiwrnod cynnar o wanwyn gyda neb o gwmpas am filltiroedd - teimlad o ryfeddod llwyr.

"A pe bai'n rhaid i fi enwi un mynydd mae'n rhaid iddo fod yn Tryfan - mae Tryfan yn eiconig."

 

Arenig Fawr


Felly beth mae Myrddyn wedi ei ddysgu o'i 20 mlynedd o ddringo'r Uchafion?

"Dwi wedi dysgu, os ydych chi'n gosod nod i chi'ch hun, i wneud eich gorau i drio ei gyflawni. Dwi wedi dysgu bod Cymru yn un o'r llefydd harddaf yn y byd. Ac mae ganddi rai bryniau anhygoel."