Sunday, 11 April 2021

Mapping Mountains – Summit Relocations – 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales

 

Ynys Fach (SN 668 951) 

There has been a Summit Relocation to a hill that is listed in the 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales, with the summit height, bwlch height and their locations, the drop, dominance and status of the hill derived by Joe Nuttall who produced a summit analysis programme using LIDAR, and then by LIDAR analysis initially conducted by Jim Bloomer and subsequently by Myrddyn Phillips. 

LIDAR image of Ynys Fach (SN 668 951)

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

30-99m Twmpau - Welsh hills at or above 30m and below 100m in height with 30m minimum drop, with an accompanying sub list 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, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 30-99m Twmpau by Myrddyn Phillips

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, with the Introduction to the Mapping Mountains publication of this list appearing on the 3rd December 2015, and the list is now available in its entirety on Mapping Mountains in Google Doc format. 

Y Trechol - The Dominant Hills of Wales by Myrddyn Phillips

The name the hill is now listed by is Ynys Fach, and it is adjoined to the Pumlumon group of hills which are situated in the north-western part of Mid and West Wales (Region B, Sub-Region B2), and it has the A487 road to its south-east and the town of Machynlleth towards the north-east. 

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

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 27m of drop based on an estimated c 34m summit height positioned at SN 670 948 and an estimated c 7m bwlch height, with both values based on interpolation of 10m contouring that appears on the Ordnance Survey 1:25,000 Explorer map, with 30m being the uppermost contour given the hill on this 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. 

The summit height produced by LIDAR analysis is 43.5m and is positioned at SN 66845 95141, and this comes within the parameters of the Summit Relocations used within this page heading, these parameters are: 

The term Summit Relocations applies when the hill’s high point is found to be positioned; in a different field, to a different feature such as in a conifer plantation, placed within a different map contour, to a different point where a number of potential summit positions are within close proximity, or 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 that is judged to be 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 43.5m and this is positioned at SN 66845 95141, this position is not given a spot height on contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps, and is approximately 300 metres north north-westward from where the previously listed summit is positioned.

 

The full details for the hill are: 

Group:  Pumlumon 

Name:  Ynys Fach 

OS 1:50,000 map:  135

Summit Height:  43.5m (LIDAR) 

Summit Grid Reference (New Position):  SN 66845 95141 (LIDAR) 

Bwlch Height:  2.1m (LIDAR) 

Bwlch Grid Reference:  SN 67483 95096 (LIDAR) 

Drop:  41.3m (LIDAR) 

Dominance:  95.10% (LIDAR) 

 

Myrddyn Phillips (April 2021)

 

 

 

Saturday, 10 April 2021

Mapping Mountains – Hill Reclassifications – 30-99m Twmpau

 

Pt. 32m (SH 281 756) – 30-99m Sub-Twmpau addition

There has been an addition to the list of 30-99m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data in combination with LIDAR analysis conducted by Myrddyn Phillips. 

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 that have 30m minimum drop, with an accompanying sub list 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, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 30-99m Twmpau by Myrddyn Phillips

The hill is being listed by the point (Pt. 32m) 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 Ynys Môn group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned with a series of minor roads to its north-west, and has the village of Trearddur towards the north-west. 

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 either category. 

After the sub list was standardised, and interpolated heights and drop values also included the details for this hill were re-evaluated and it was listed with an estimated c 19m of drop based on the 32m summit spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map, and an estimated c 13m bwlch height based on interpolation of 5m contouring between 10m – 15m that appears on the Ordnance Survey 1:25,000 Explorer map. 

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

Since the original publication of the P30 lists on Geoff Crowder’s v-g.me website and the re-assessment of this hill’s details there have been a number of Ordnance Survey 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 are current and digitally updated such as the mapping on the Magic Maps website. 

Extract from the Magic Maps website

One of the mapping resources now available online is the Magic Maps website which hosts an interactive map originated from Ordnance Survey data.  This mapping has many spot heights not on other publicly available Ordnance Survey maps and for this hill the 32m summit spot height is also given on the area of its summit, with the caveat that the Ordnance Survey 1:50,000 Landranger map gives a 33m summit spot height in approximately the same position. 

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 bwlch image of Pt. 32m (SH 281 756)

Therefore, the addition of this hill to 30-99m Sub-Twmpau status is due to detail on contemporary maps produced from Ordnance Survey data in combination with LIDAR bwlch analysis, resulting in a 32m summit height and an 11.9m bwlch height, with these values giving this hill 20m of drop, which is sufficient for it to be classified as a 30-99m Sub-Twmpau. 

 

The full details for the hill are: 

Group:  Ynys Môn 

Name:  Pt. 32m 

OS 1:50,000 map:  114

Summit Height:  32m (spot height) 

Summit Grid Reference:  SH 28120 75648 (spot height) 

Bwlch Height:  11.9m (LIDAR) 

Bwlch Grid Reference:  SH 27589 76108 (LIDAR) 

Drop:  20m (spot height summit and LIDAR bwlch) 

 

Myrddyn Phillips (April 2021)

 

 

 

Mapping Mountains – Significant Name Changes – Y Trichant – The 300m Hills of Wales

 

Ffriddoedd (SH 901 368) 

There has been a Significant Name Change 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 confirmed by a Trimble GeoXH 6000 survey conducted by Myrddyn Phillips. 

Ffriddoedd (SH 901 368)

The criteria for the list that this name change 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. 

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

The hill is adjoined to the Arenig group of hills, which are situated in the central part of North Wales (Region A, Sub-Region A3), and it is positioned with the A4212 road to its north-east and the A494 road to its south-east, and has the town of Y Bala towards the east south-east. 

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

When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was listed under the invented and transposed name of Pen Ty’n-y-bryn, with an accompanying note stating; Name from buildings to the North-East.


Pen Ty'n-y-bryn330cSH90236912518Name from buildings to the North-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.  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. 

As the summit of this hill comprises bounded land the details for it were examined on the Tithe map.  The term Tithe map is generally given to a map of a Welsh or English parish or township and which was prepared after the 1836 Tithe Commutation Act.  This act allowed tithes to be paid in cash rather than goods.  The Tithe maps gave names of owners and occupiers of land in each parish and importantly for place-name research they also included the name of enclosed land.  This enclosed land is usually based on a field system, however not every field is given a name, but many are and especially so in Wales. 

Extract from the Tithe map

The enclosed land where the summit of this hill is situated is given the number 1024 on the Tithe map, this can be cross referenced against the apportionments; it is these apportionments that give the name of the owner or occupier of the land as well as the name of the land.  The land where the summit of this hill is situated is named as Ffriddoedd, with the details on the Tithe map appearing in the parish of Llanycil and in the county named as Merionethshire. 

Extract from the apportionments

Therefore, the name this hill is now listed by in the Y Trichant – The 300m Hills of Wales is Ffriddoedd, and this was derived from the Tithe map. 

 

The full details for the hill are: 

Group:  Arenig 

Name:  Ffriddoedd 

Previously Listed Name:  Pen Ty’n-y-bryn 

OS 1:50,000 map:  125

Summit Height:  332.3m (converted to OSGM15)                                                           

Summit Grid Reference:  SH 90190 36854 

Bwlch Height:  297.8m (converted to OSGM15) 

Bwlch Grid Reference:  SH 90167 36446 

Drop:  34.4m 

 

Myrddyn Phillips (April 2021)

 

 

Friday, 9 April 2021

Mapping Mountains – Significant Name Changes – The Welsh P15s

 

Mynydd Twr (SH 207 824) 

There has been a Significant Name Change to a hill that is listed in The Welsh P15s, with the summit height, bwlch height and their locations, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data. 

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

The Welsh P15s – Welsh hills with 15m minimum drop, irrespective of their height, with an accompanying sub list entitled the Welsh Sub-P15s, with the criteria for this sub category being all Welsh hills with 14m or more and below 15m of drop.  The list is authored by Myrddyn Phillips, with the Introduction to the list appearing on Mapping Mountains on the 10th May 2019. 

The Welsh P15s by Myrddyn Phillips

The hill is adjoined to the Ynys Môn group of hills, which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned overlooking the coast to its north and west and has minor roads to its south and east, and has the town of Caergybi (Holyhead) towards the east. 

When the listing that became known as The Welsh P15s was being compiled, this hill was listed under the point (Pt. 142m) notation with an estimated c 19m of drop, based on the 142m summit spot height that appears on the Ordnance Survey 1:25,000 Explorer map and an estimated c 123m bwlch height based on interpolation of 5m contouring between 120m – 125m. 

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

As the summit of this hill comprises bounded land the details for it were examined on the Tithe map.  The term Tithe map is generally given to a map of a Welsh or English parish or township and which was prepared after the 1836 Tithe Commutation Act.  This act allowed tithes to be paid in cash rather than goods.  The Tithe maps gave names of owners and occupiers of land in each parish and importantly for place-name research they also included the name of enclosed land.  This enclosed land is usually based on a field system, however not every field is given a name, but many are and especially so in Wales. 

Extract from the Tithe map

The enclosed land where the summit of this hill is situated is given the number 537 on the Tithe map, this can be cross referenced against the apportionments; it is these apportionments that give the name of the owner or occupier of the land as well as the name of the land.  However, the Tithe map can also be used to substantiate land boundaries and this map names this land as a part of the larger Mynydd Twr. 

Therefore, the name this hill is now listed by in The Welsh P15s is Mynydd Twr, and this was derived from the hill being a part of the land of the larger mountain known as Mynydd Twr, with the land boundary substantiated by the Tithe map. 

 

The full details for the hill are: 

Group:  Ynys Môn 

Name:  Mynydd Twr

Previously Listed Name:  Pt. 142m 

OS 1:50,000 map:  114

Summit Height:  142m (spot height) 

Summit Grid Reference:  SH 20748 82447 (spot height) 

Bwlch Height:  c 123m (interpolation) 

Bwlch Grid Reference:  SH 20906 82363 (interpolation) 

Drop:  c 19m (spot height summit and interpolated bwlch) 

 

Myrddyn Phillips (April 2021)

 

 

Mapping Mountains – Hill Reclassifications – 100m Twmpau

 

Pt. 104.3m (SN 712 990) – 100m Sub-Twmpau reclassified to 100m Twmpau

There has been confirmation of a reclassification to the list of 100m Twmpau, 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 Pt. 104.3m (SN 712 990)

The criteria for the list that this reclassification 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. 

The 100m Twmpau by Myrddyn Phillips

The hill is being listed by the point (Pt. 104.3m) 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 Pumlumon group of hills, which are situated in the north-western part of Mid and West Wales (Region B, Sub-Region B2), and it has the A487 road to its north and west, and a minor road to its immediate south-east, and has the town of Machynlleth towards the north north-east. 

When the original 100m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was included in the Hills to be surveyed sub list that accompanied the main P30 list, as it was considered not to meet the criteria then used for the main P30 category. 

When 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 an estimated c 25m of drop, based on an estimated c 102m summit height and an estimated c 177m bwlch height, both heights based on interpolation of 10m contouring that appear on the Ordnance Survey 1:25,000 Explorer map. 

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

The details for this hill we re-assessed when the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map became available online.  This mapping had many spot heights not on other publicly available Ordnance Survey maps and for this hill a 104m spot height was given on the area of its summit and with a re-appraisal of its estimated bwlch height to c 74m, these values gave this hill an estimated c 30m of drop. 

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 reclassification of this hill from 100m Sub-Twmpau status is due to LIDAR analysis, resulting in a 104.3m summit height and a 73.0m bwlch height, with these values giving this hill 31.2m of drop, which is sufficient for it to be classified as a 100m Twmpau.

 

The full details for the hill are: 

Group:  Pumlumon 

Name:  Pt. 104.3m 

OS 1:50,000 map:  135

Summit Height:  104.3m (LIDAR) 

Summit Grid Reference:  SN 71207 99002 (LIDAR) 

Bwlch Height:  73.0m (LIDAR) 

Bwlch Grid Reference:  SN 71498 98989 (LIDAR) 

Drop:  31.2m (LIDAR) 

 

Myrddyn Phillips (April 2021)

 

 

 

 

 

 

Thursday, 8 April 2021

Mapping Mountains – Significant Name Changes – 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales

 

Cadair Pedwar Gwynt (SH 263 753) 

There has been a Significant Name Change to a hill that is listed in the 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales, with the summit height, bwlch height and their locations, the drop, dominance and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data and by LIDAR analysis conducted by Myrddyn Phillips. 

Cadair Pedwar Gwynt (SH 263 753)

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

30-99m Twmpau - Welsh hills at or above 30m and below 100m in height with 30m minimum drop, with an accompanying sub list 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, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward. 

The 30-99m Twmpau by Myrddyn Phillips

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 3rd December 2015, and which is now available in its entirety on Mapping Mountains in Google Doc format. 

Y Trechol - The Dominant Hills of Wales by Myrddyn Phillips

The hill is adjoined to the Ynys Môn group of hills which are situated in the north-western part of North Wales (Region A, Sub-Region A1), and it is positioned on Ynys Gybi (Holyhead Island) to the west of Ynys Môn, and has the coast to its immediate south-west and minor roads to its north-east and the B4545 road farther to its north, and has the village of Trearddur towards the north north-west. 

The hill appeared in the original 30-99m Welsh P30 list on Geoff Crowder’s v-g.me website under the transposed name of Hirfron, with an accompanying note stating; Name from buildings to the East.


Hirfron63mSH263753114262Trig pillar. Name from buildings 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 building and use it for that of the hill.  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

This was one of a number of hills visited during the day and before starting the short walk to its summit I made local enquiries concerning its name, starting at the White Eagle pub.  I was directed by four people who were finishing their lunch to Haulfryn, where Susan Roberts lived.  Susan is a school teacher and was sitting on a reclining chair with a duvet over her having not gone to work due to illness.  She invited me in and we chatted for about 30 minutes and she told me the high point of the hill is known as Cadair Pedwar Gwynt after the seat constructed on its summit, explaining that it is also known as Lady Verney’s Seat. 

Therefore, the name this hill is now listed by in the 30-99m Twmpau and Y Trechol – The Dominant Hills of Wales is Cadair Pedwar Gwynt, and this was derived from local enquiry. 

 

The full details for the hill are: 

Group:  Ynys Môn 

Name:  Cadair Pedwar Gwynt

Previously Listed Name:  Hirfron 

OS 1:50,000 map:  114

Summit Height:  c 64m (interpolation)

Summit Grid Reference:  SH 26349 75310 (hand-held GPS via DoBIH)

Bwlch Height:  4.45m (LIDAR)

Bwlch Grid Reference:  SH 25393 79147 (LIDAR) 

Drop:  c 59m (interpolated summit and LIDAR bwlch)

Dominance:  93.03% (interpolated summit and LIDAR bwlch)

 

Myrddyn Phillips (April 2021)