Tuesday, 31 August 2021

Mapping Mountains – Significant Name Changes – The Welsh P15s

 

Pen Ucheldref (SH 349 882) 

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 and LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Pen Ucheldref (SH 349 882)

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 with two minor roads beside its summit and the A5025 road to its north-west, and has the village of Llanrhuddlad also towards the north-west. 

When the listing that became known as The Welsh P15s was being compiled, this hill was listed under the point (Pt. c 90m) notation with an estimated c 23m of drop, based on an estimated c 90m summit height and an estimated c 67m bwlch height, with both heights based on interpolation of 5m contouring that appears on the Ordnance Survey 1:25,000 Explorer map, with the 85m upper summit contour mistaken for 90m. 

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 6 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 Pen Ucheldref in the apportionments, with the details on the Tithe map appearing in the parish of Llanfflewin and in the county named as Anglesey. 

Extract from the apportionments

Therefore, the name this hill is now listed by in The Welsh P15s is Pen Ucheldref and this derived from the Tithe map. 

 

The full details for the hill are: 

Group:  Ynys Môn 

Name:  Pen Ucheldref

Previously Listed Name:  Pt. c 90m 

OS 1:50,000 map:  114

Summit Height:  85.4m (LIDAR) 

Summit Grid Reference:  SH 34917 88259 (LIDAR) 

Bwlch Height:  c 67m (interpolation) 

Bwlch Grid Reference:  SH 35183 88544 (interpolation) 

Drop:  c 18m (LIDAR summit and interpolated bwlch) 

 

Myrddyn Phillips (August 2021)

 

 

 

 

 

 

Mapping Mountains – Trimble Surveys – Carnedd Wen

 

02.07.21  Quarry Field (SJ 183 147) 

Quarry Field (SJ 183 147)

Prior to visiting this hill I had analysed its numerical data via LIDAR and confirmed it as a P20 Sub-Twmpau.  I had also looked at its uppermost enclosed field on the Tithe map for an appropriate name to use for that of the hill.  This walk also fitted nicely in to a circuit of five hills I could visit during the morning as due to afternoon commitments I needed to be home by 1.00pm.

LIDAR image of Quarry Field (SJ 183 147)

By the time I parked close to Cil Bach farm, under a convenient large tree giving a shaded spot to leave my car, the heat of the morning was increasing and with a forecast of possible late afternoon showers and thunder, I was glad of the excuse of those afternoon commitments and to get home before any heavy rain materialised. 

At the time of the Tithe the upper field of this hill was named Cae Bryn (no doubt documented by an English scribe as it is written as Cae Brin).  This would be an appropriate name to use for this small heighted hill, but as ever; if I could find the local farmer I was sure this name would either be confirmed or a current name given. 

Leaving my car I walked the short distance up the narrow lane to where a track veered left, following this gave access to the upper field which was planted with wheat.  I noticed this when driving toward the hill as its upper section shimmered in the light against a slight breeze.  Wheat fields are a delight to encounter; usually they have good vehicle tracks leading across them, and thankfully near to where I emerged next to the field a vehicle track headed up cresting the upper part of the hill close to its high point. 

As I walked up the vehicle track leading through the wheat I noticed Cwm Farm below.  I was in view of this farm, therefore did not want to linger at the summit however delightful wheat fields can be. 

Once near the high point I zeroed in to the summit position using the Trimble as a hand-help GPS unit with the ten figure grid reference produced via LIDAR leading me to the high point.  Once at the summit I set the Trimble up on top of my rucksack, which gives it elevation above its immediate surrounds and acts as an improvised tripod.  I quickly measured the offset between its internal antenna and the ground at its base and waited for the 0.1m accuracy level to be attained before data should be logged.  Once this appeared on the equipment’s screen I pressed ‘Log’ and walked the short distance back to the vehicle track. 

During data collection I sat on one of the tracks submerged beside the wheat.  I’d done something similar on previous occasions whilst surveying; these have usually been at bylchau, it doesn’t happen very often at a summit.  Whenever it does, be it summit or bwlch, it always brings a smile to my face as it is an unusual place to find oneself; sitting submerged in a field full of maturing crops.  This is not something that I imagine happens to many people and especially when one considers the purpose of the situation, but purpose and situation sometimes dictate and today that is exactly what happened. 

My view whilst waiting for the Trimble to gather data

Time out during data collection!

Considering its position the Trimble attained its 0.1m accuracy level remarkably quickly and gathered its five minutes of allotted data without any complaint, as sometimes when satellite reception is not good it squeals in anger and frustration! 

Gathering data at the summit of Quarry Field 

Once five minutes of data were gathered and stored I closed the equipment down, took a few photographs and packed it away.  Turning away from the summit I headed down the vehicle track amongst the wheat, thinking that a few minutes later I would be back at my car.  However, soon after leaving the summit a farm vehicle came chugging its way up the near gravelled track, and by the time I was out of the wheat it was making its way toward me.  My luck was certainly in as it was the local farmer; Richard Morris from Cil Farm. 

I talked with Richard for 15 minutes or so, it turned out that he used to go to school with my old boss and was friends with another ex-work colleague who lived in Meifod.  He also knew other friends I have from the village. 

Richard explained that he grew up in this community and farmed all his life, but only took over this field three years ago.  He knew the upper field as the Quarry Field after the disused small quarry near-by.  I mentioned the name Cae Bryn to him, which he had never heard.  I explained where I had been and the hills visited, and he then told me that he is also the local farmer for my previously visited hill, which is positioned at SJ 171 137, he told me its name is Dol Gron. 

Richard Morris of Cil Farm

When back home I checked the Ordnance Survey series of Six-Inch maps and there under the hill positioned at SJ 171 137 is an old house named Ddol-gron, with the near wood also named as Coed Ddol-gron.  Dol Gron is translated in to English as the Round or Rounded Meadow, an apt description of the hill and especially so for its upper section. 

Thanking Richard for his time I waited for him to continue down the gravelled track before I followed on foot.  I was back at my car at just before 10.50am, the walk and survey and meeting Richard had taken 50 minutes and proved very enjoyable and importantly gave names for the last two hills I had visited.  Only one hill remained for my morning’s little hill foray; this was Y Gaer (SJ 204 155) which I wanted to re-survey as during my previous visit the Trimble was placed on top of the earthen section of a covered reservoir and as this is a relatively recent man-made construct it should not be included in the height of a hill, therefore I now wanted to gather data from natural ground at its base.

 

Survey Result: 

 

Quarry Field (significant name change)

Summit Height:  109.5m (converted to OSGM15, Trimble GeoXH 6000)

Summit Grid Reference:  SJ 18332 14741 (Trimble GeoXH 6000) 

Bwlch Height:  86.6m (LIDAR)

Bwlch Grid Reference:  SJ 18549 14551 (LIDAR)

Drop:  22.9m (Trimble GeoXH 6000 summit and LIDAR bwlch) (100m Sub-Twmpau addition)

Dominance: 20.89% (Trimble GeoXH 6000 summit and LIDAR bwlch)

 

 

For further details please consult the Trimble Survey Spreadsheet

 

 

 

 

 

 

 

Monday, 30 August 2021

Mapping Mountains – Hill Reclassifications – 30-99m Twmpau

 

Bryn Ifan (SH 336 703) – 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 LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Bryn Ifan (SH 336 703)

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 name the hill is listed by is Bryn Ifan 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 the coast to its west and the A4080 road to its north-east, and has the village of Aberffraw towards the south-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 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-evaluated and it was listed with an estimated c 19m of drop, based on an estimated c 42m summit height and an estimated c 23m bwlch height, with both values based on interpolation of 5m contouring that appears on the 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 addition of this hill to 30-99m Sub-Twmpau status is due to LIDAR analysis, resulting in a 43.4m summit height and a 23.2m bwlch height, with these values giving this hill 20.2m 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:  Bryn Ifan 

OS 1:50,000 map:  114

Summit Height:  43.4m (LIDAR) 

Summit Grid Reference:  SH 33612 70347 (LIDAR)               

Bwlch Height:  23.2m (LIDAR) 

Bwlch Grid Reference:  SH 35753 72013 (LIDAR) 

Drop:  20.2m (LIDAR) 

 

Myrddyn Phillips (August 2021)

 

 

 

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


Ynys Hir (SN 679 957) 

There has been a Significant Height Revision 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 Chris Crocker and subsequently by Myrddyn Phillips. 

LIDAR image of Ynys Hir (SN 679 957)

The criteria for the two listings that this height revision 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 listed by is Ynys Hir, 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 is positioned with the Afon Dyfi (River Dovey) and the coast to its west and has the A487 road to its east and the village of Y Borth towards the south-west. 

When the original 30-99m height band of Welsh P30 hills was published on Geoff Crowder’s v-g.me website this hill was included in the main P30 list with a summit height of c 40m.  

When 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 41m of drop, based on an estimated c 48m summit height 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 40m 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 61.1m and 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, this hill’s new listed summit height is 61.1m and this was derived from LIDAR analysis, this is 13.1m higher than the previous listed summit height of c 48m which was derived from interpolation of the uppermost contour given the hill on contemporary Ordnance Survey 1:25,000 Explorer maps.

 

ills of Wales, and are reproduced below@

The full details for the hill are:

Group:  Pumlumon 

Name:  Ynys Fach 

OS 1:50,000 map:  135

Summit Height (New Height):  61.1m (LIDAR) 

Summit Grid Reference:  SN 67972 95798 (LIDAR) 

Bwlch Height:  6.8m (LIDAR) 

Bwlch Grid Reference:  SN 68354 95558 & SN 68368 95541 (LIDAR) 

Drop:  54.35m (LIDAR) 

Dominance:  88.91% (LIDAR)

 

Myrddyn Phillips (August 2021)

 

 

  

Sunday, 29 August 2021

Mapping Mountains – Summit Relocations – The Welsh P15s

 

Pen Ucheldref (SH 349 882) 

There has been a Summit Relocation to a hill that is listed in the 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 and LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Pen Ucheldref (SH 349 882)

The criteria for the list that this summit relocation 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 name the hill is listed by is Pen Ucheldref and this was derived from the Tithe map, 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 two minor roads beside its summit and the A5025 road to its north-west, and has the village of Llanrhuddlad also towards the north-west. 

When the listing that became known as The Welsh P15s was being compiled, this hill was listed with an estimated c 23m of drop, based on an estimated c 90m summit height positioned at SH 34812 87943 and an estimated c 67m bwlch height, with both heights based on interpolation of 5m contouring that appears on the Ordnance Survey 1:25,000 Explorer map, with the 85m upper summit contour mistaken for 90m. 

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 85.4m and is positioned at SH 34917 88259, 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, within a different map contour, to a different feature such as in a conifer plantation, to a different point where a number of potential summit positions are within close proximity, 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 natural ground or the natural and intact summit is confirmed compared to a higher point such as a raised field boundary that is judged to be a relatively recent man-made construct. 

Therefore, the summit height produced by LIDAR analysis is 85.4m and this is positioned at SH 34917 88259, this position is given an 85m spot height on contemporary Ordnance Survey 1:50,000 Landranger maps and an 84m spot height on contemporary Ordnance Survey 1:25,000 Explorer maps, and is approximately 320 metres northward from where the previously listed summit is positioned. 

 

The full details for the hill are: 

Group:  Ynys Môn 

Name:  Pen Ucheldref 

OS 1:50,000 map:  114

Summit Height:  85.4m (LIDAR) 

Summit Grid Reference (New Position):  SH 34917 88259 (LIDAR) 

Bwlch Height:  c 67m (interpolation) 

Bwlch Grid Reference:  SH 35183 88544 (interpolation) 

Drop:  c 18m (LIDAR summit and interpolated bwlch) 

 

Myrddyn Phillips (August 2021)