Showing posts with label Bwlchwernen Fach. Show all posts
Showing posts with label Bwlchwernen Fach. Show all posts

Monday, 15 January 2024

Mapping Mountains – Significant Name Changes – 200m Twmpau


Bwlchwernen Fach (SN 606 556) 

There has been a Significant Name Change 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 LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Bwlchwernen Fach (SN 606 556)

The criteria for the list that this name change 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. 

The 200m Twmpau by Myrddyn Phillips

The hill is adjoined to the Mynydd Bach group of hills, which are situated in the western part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its north and west, and the A485 road to its south-east, and has the village of Llanddewibrefi towards the east.

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 accompanying 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-evaluated and it was listed under the name of Allt Gelligarneddau, which is a prominent name that appears to the north of the summit of this hill on the contemporary Ordnance Survey 1:25,000 Explorer map. 

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

During my early hill listing I paid little regard to name placement on the map, or the meaning of names and to what feature the name was appropriately applied to.  Therefore, I prioritised names for listing purposes that I now understand are either inappropriate or where another name is viewed as being more appropriate.  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.

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.

The Ordnance Survey series of Six-Inch maps formed the base map Ordnance Survey used for many decades leading to the production of the 1:10,000 Series of maps, both have now been superseded by the digitised Master Map.  The series of Six-Inch maps are excellent for name placement and especially so compared to the contemporary Ordnance Survey 1:25,000 Explorer map, and it is the series of Six-Inch maps that position the name of Allt Gelligarneddau applicable to a wood to the north-east of the summit of this hill.  This is named land associated with the farm of Gelligarneddau which is positioned at SN 608 554.

Extract from the Ordnance Survey series of Six-Inch maps

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 highest remaining natural ground of this hill is situated is given the number 281 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 a part of Bwlchwernen Fach in the apportionments, with the details on the Tithe map appearing in the parish of Llangybi and in the county named as Cardigan. 

Extract from the apportionments

Therefore, the name this hill is now listed by in the 200m Twmpau is Bwlchwernen Fach and this was derived from the Tithe map. 

 

The full details for the hill are:

Group:  Mynydd Bach

Name:  Bwlchwernen Fach

Previously Listed Name:  Allt Gelligarneddau   

OS 1:50,000 map:  146

Summit Height:  256.35m (LIDAR) 

Summit Grid Reference:  SN 60699 55684 (LIDAR) 

Bwlch Height:  230.7m (LIDAR) 

Bwlch Grid Reference:  SN 60598 55268 (LIDAR) 

Drop:  25.7m (LIDAR) 

 

Myrddyn Phillips (January 2024)

 

 

 

  

Thursday, 11 January 2024

Mapping Mountains – Summit Relocations – 200m Twmpau

 

Bwlchwernen Fach (SN 606 556) 

There has been a Summit Relocation 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 LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Bwlchwernen Fach (SN 606 556)

The criteria for the list that this summit relocation 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. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Bwlchwernen Fach and this was derived from the Tithe map, and it is adjoined to the Mynydd Bach group of hills, which are situated in the western part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its north and west, and the A485 road to its south-east, and has the village of Llanddewibrefi towards the east.

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 accompanying 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-evaluated and it was listed with an estimated c 24m of drop, based on the 256m summit spot height positioned at SN 60698 55674 that appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated c 232m bwlch height, based on interpolation of 10m contouring between 230m – 240m. 

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 analysis gives the highest ground on this hill as 257.4m positioned at SN 60696 55677.  However, this is a part of a raised field boundary and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill. 

LIDAR summit image of Bwlchwernen Fach (SN 606 556)

The height produced by LIDAR analysis to the highest remaining natural ground of this hill is 256.35m positioned at SN 60699 55684, and this position in relation to the raised field boundary 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 256.35m and this is positioned at SN 60699 55684, this position is close to where the 256m spot height appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and is approximately 7 metres north-eastward from the high point of the raised field boundary. 

 

The full details for the hill are: 

Group:  Mynydd Bach 

Name:  Bwlchwernen Fach 

OS 1:50,000 map:  146

Summit Height:  256.35m (LIDAR) 

Summit Grid Reference (New Position):  SN 60699 55684 (LIDAR) 

Bwlch Height:  230.7m (LIDAR) 

Bwlch Grid Reference:  SN 60598 55268 (LIDAR) 

Drop:  25.7m (LIDAR) 

 

Myrddyn Phillips (January 2024)

 

 

 

Friday, 5 January 2024

Mapping Mountains – Hill Reclassifications – 200m Twmpau


Bwlchwernen Fach (SN 606 556) – 200m Sub-Twmpau addition

There has been confirmation of an addition to the list of 200m 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 Bwlchwernen Fach (SN 606 556)

The criteria for the list that this addition 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. 

The 200m Twmpau by Myrddyn Phillips

The name the hill is now listed by is Bwlchwernen Fach and this was derived from the Tithe map, and it is adjoined to the Mynydd Bach group of hills, which are situated in the western part of South Wales (Region B, Sub-Region B1), and it is positioned with minor roads to its north and west, and the A485 road to its south-east, and has the village of Llanddewibrefi towards the east.

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 accompanying 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-evaluated and it was listed with an estimated c 24m of drop, based on the 256m summit spot height that appears on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated c 232m bwlch height, based on interpolation of 10m contouring between 230m – 240m. 

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 200m Sub-Twmpau status is due to LIDAR analysis, resulting in a 256.35m summit height and a 230.7m bwlch height, with these values giving this hill 25.7m of drop, which is sufficient for it to be classified as a 200m Sub-Twmpau. 

 

The full details for the hill are: 

Group:  Mynydd Bach 

Name:  Bwlchwernen Fach 

OS 1:50,000 map:  146

Summit Height:  256.35m (LIDAR) 

Summit Grid Reference:  SN 60699 55684 (LIDAR) 

Bwlch Height:  230.7m (LIDAR) 

Bwlch Grid Reference:  SN 60598 55268 (LIDAR) 

Drop:  25.7m (LIDAR) 

 

Myrddyn Phillips (January 2024)