Friday, 21 February 2020

Mapping Mountains - Hill Reclassifications - Humps


Humps – Hill Reclassifications

The Humps (HUndred Metre Prominences) are all hills in Britain that have a minimum drop of 100m, irrespective of their height, accompanying the main list is a sub-list entitled Subhumps with the criteria being all hills in Britain that have 90m and more and below 100m of drop.  The listing of Humps was published in book format by Lulu in 2009 and entitled More Relative Hills of Britain, its author; Mark Jackson gives credit to a number of people who contributed toward the formation of this list, these include; Eric Yeaman, Alan Dawson, Clem Clements, Rob Woodall, Bernie Hughes, Pete Ridges and others.

The posts that have appeared on Mapping Mountains detailing the hill reclassifications specifically for this list appear below presented chronologically in receding order.









Mapping Mountains - Hill Reclassifications - Humps

Way Stone Edge (SD 999 140) – proposed Subhump deletion (40th reclassification)


This is the fourtieth in a series of Hill Reclassification posts that detail hills whose status has either been altered in the listing of the Humps (HUndred Metre Prominences) through map study, surveys or LIDAR analysis that I have been involved in, or it is the recommendation that their status is altered.

LIDAR summit image of Way Stone Edge (SD 999 140)

Many preceding posts detailing these hill reclassifications are retrospective as they were initiated from studying the Ordnance Survey Vector Map Local that was hosted on the Geograph website and which was entitled the Interactive Coverage Map, or from surveying with the Trimble GeoXH 6000, or from LIDAR analysis, and for this proposed deletion that affects the Humps the email I posted on the pedantic@groups.io forum in relation to this hill was dated 20.06.23.

The listing of Humps was published in book format by Lulu in 2009 and entitled More Relative Hills of Britain, its author; Mark Jackson gives credit to a number of people who contributed toward the formation of this list, these include; Eric Yeaman, Alan Dawson, Clem Clements, Rob Woodall, Bernie Hughes, Pete Ridges and others.  When the list was published in book format there were 2987 Humps listed with their criteria being any British hill that has 100m or more of drop, irrespective of their height.  Accompanying the main list is a sub category entitled Subhumps, with the criteria being any British hill that has 90m or more and below 100m of drop.

More Relative Hills of Britain by Mark Jackson

The details for this proposed deletion appear below:

The name the hill is listed by is Way Stone Edge, and it is the highest hill in its own group of hillswhich are situated in the southern Pennines, and it is positioned with the M62 motorway and the A672 road to its north-west, and the A640 road to its south-east, and has the village of Denshaw towards the south south-west. 

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

This hill is currently listed as a Subhump with 94m of drop based on the 418.6m summit height ascertained from LIDAR analysis and a 388m col height, based on the spot height that appears on the Ordnance Survey 1:25,000 Explorer map.  The proposed deletion of this hill in the listing of the Humps (HUndred Metre Prominences) was instigated by LIDAR analysis conducted by Myrddyn Phillips.

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

The col height of 388m for the listed drop value of 94m is taken to the A62 cutting.  The protocol followed in the listing of the Humps specifies that the height of an extant natural col is favoured over that of the height in the depth of a cutting, even if the latter is lower on the hill to hill traverse.  As LIDAR contouring implies the natural col for this hill is intact, it is this height value that should be taken for the listing of the Humps within the drop of this hill.

LIDAR col image of Way Stone Edge

Therefore, the proposed deletion of this hill from Subhump status is due to LIDAR analysis, resulting in a 481.6m summit height and a 399.6m col height, with these values giving this hill 82.1m of drop.

 

The full details for the hill are:

Name:  Way Stone Edge

OS 1:50,000 map:  109

OS 1:25,000 map:  21

Summit Height:  481.6m (LIDAR)

Summit Grid Reference:  SD 99953 14049 (as listed in the Humps, with LIDAR analysis giving SD 99956 14046)

Col Height:  388m (as listed in the Humps, with LIDAR analysis giving 399.6m to the natural col)

Col Grid Reference:  SE 019 095 (as listed in the Humps, with LIDAR analysis giving SE 02035 09664)

Drop:  94m (as listed in the Humps, with LIDAR analysis giving 82.1m using the natural col)

 

Myrddyn Phillips (July 2023)

 

 


Mapping Mountains - Hill Reclassifications - Humps

Cefn Dreiniog (SJ 145 147) – proposed Subhump deletion (39th reclassification)


This is the thirty ninth in a series of Hill Reclassification posts that detail hills whose status has either been altered in the listing of the Humps (HUndred Metre Prominences) through map study, surveys or LIDAR analysis that I have been involved in, or it is the recommendation that their status is altered.

Cefn Dreiniog (SJ 145 147)

Many preceding posts detailing these hill reclassifications are retrospective as they were initiated from studying the Ordnance Survey Vector Map Local that was hosted on the Geograph website and which was entitled the Interactive Coverage Map, or from surveying with the Trimble GeoXH 6000, or from LIDAR analysis, and for this proposed deletion that affects the Humps the email I posted on the pedantic@groups.io forum in relation to this hill was dated 24.03.21.

The listing of Humps was published in book format by Lulu in 2009 and entitled More Relative Hills of Britain, its author; Mark Jackson gives credit to a number of people who contributed toward the formation of this list, these include; Eric Yeaman, Alan Dawson, Clem Clements, Rob Woodall, Bernie Hughes, Pete Ridges and others.  When the list was published in book format there were 2987 Humps listed with their criteria being any British hill that has 100m or more of drop, irrespective of their height.  Accompanying the main list is a sub category entitled Subhumps, with the criteria being any British hill that has 90m or more and below 100m of drop.

More Relative Hills of Britain by Mark Jackson

The details for this proposed deletion appear below:

There has been a propose deletion to the listing of the Humps (HUndred Metre Prominences) instigated by a combination of detail on maps produced from Ordnance Survey data and a Trimble GeoXH 6000 survey conducted by Myrddyn Phillips.

The name the hill is listed by is Cefn Dreiniog and it is adjoined to the Y Berwyn group of hills, and it is encircled by minor roads with the A495 road farther to its south-east, and has the village of Meifod towards the south south-east.

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

This hill is currently listed as a Subhump with 90m of drop based on the 318m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps and the 228m bwlch spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.

The Trimble GeoXH 6000 gathering data at the summit of Cefn Dreiniog

This hill was subsequently surveyed on the 16.03.21 by Myrddyn Phillips using a Trimble GeoXH 6000, resulting in a 317.1m summit height and when coupled with the 228m bwlch height, these values give this hill 89m of drop, which is insufficient for Sumhump status.

 

The full details for the hill are:

Name:  Cefn Dreiniog

OS 1:50,000 map:  125

OS 1:25,000 map:  239

Summit Height:  318m (as listed in the Humps, with the Trimble GeoXH 6000 survey giving 317.1)

Summit Grid Reference:  SJ 14508 14704 (as listed in the Humps, with the Trimble GeoXH 6000 survey giving SJ 14506 14701)

Bwlch Height:  228m

Bwlch Grid Reference:  SJ 140 148

Drop:  90m (as listed in the Humps with the Trimble GeoXH 6000 summit survey and bwlch spot height giving 89m)

 

Myrddyn Phillips (July 2021)




Mapping Mountains - Hill Reclassifications - Humps

Werfa (SS 912 947) – Subhump deletion (38th reclassification)


This is the thirty eighth in a series of Hill Reclassification posts that detail hills whose status has either been altered in the listing of the Humps (HUndred Metre Prominences) through map study, surveys or LIDAR analysis that I have been involved in, or it is the recommendation that their status is altered.

Werfa (SS 912 947) 

Many preceding posts detailing these hill reclassifications are retrospective as they were initiated from studying the Ordnance Survey Vector Map Local that was hosted on the Geograph website and which was entitled the Interactive Coverage Map, or from surveying with the Trimble GeoXH 6000, or from LIDAR analysis, and for this deletion that affected the Humps the email I posted on the Tump Googlegroups forum in relation to this hill was dated 12.11.20.

The listing of Humps was published in book format by Lulu in 2009 and entitled More Relative Hills of Britain, its author; Mark Jackson gives credit to a number of people who contributed toward the formation of this list, these include; Eric Yeaman, Alan Dawson, Clem Clements, Rob Woodall, Bernie Hughes, Pete Ridges and others.  When the list was published in book format there were 2987 Humps listed with their criteria being any British hill that has 100m or more of drop, irrespective of their height.  Accompanying the main list is a sub category entitled Subhumps, with the criteria being any British hill that has 90m or more and below 100m of drop.

More Relative Hills of Britain by Mark Jackson

The details for this deletion appear below:

There has been a deletion to the listing of the Humps (HUndred Metre Prominences) instigated by LIDAR analysis initially conducted by Aled Williams and then independently by Joe Nuttall who produced a summit analysis programme based on heights and drops of hills produced by LIDAR, and as there was a discrepancy in bwlch position for these two studies LIDAR analysis was then conducted by Myrddyn Phillips.

LIDAR bwlch image of Werfa

The bwlch of Werfa

The name the hill is listed by is Werfa and it is adjoined to the Cymoedd group of hills, and it is positioned with the A4190 road to its north-east, and has the village of Abergwynfi towards the north-west.

Prior to this deletion this hill was listed as a Subhump with 90m of drop based on the 568m summit spot height adjoined to a triangulation pillar and which appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps and a bwlch height of c 478m based on interpolation of 10m contouring between 470m – 480m.

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

However, the advent of LIDAR has meant greater accuracy for summit and bwlch heights and their positions.  Currently LIDAR only covers the bwlch of this hill and analysis gives a natural bwlch height of 479.9m positioned at SS 91189 97075.  This re-assessment resulted in a recommendation of this hill being deleted from Subhump status with 88m of drop.

This summit of this hill was subsequently surveyed on the 17.04.21 by Myrddyn Phillips and Aled Williams using a Trimble GeoXH 6000, resulting in a 567.5m summit height and when coupled with the 479.9m bwlch height ascertained from LIDAR analysis, these values give this hill 87.5m of drop.

The Trimble GeoXH 6000 gathering data at the summit of Werfa

The listing of the Humps was updated with the deletion of this hill from Subhump status and this was augmented on the 06.02.21.

 

The full details for the hill are:

Name:  Werfa [Mynydd Llangeinwyr] (as listed in the Humps)

OS 1:50,000 map:  170

OS 1:25,000 map:  166

Summit Height:  568m (as listed in the Humps, with the Trimble GeoXH 6000 survey giving 567.5m)

Summit Grid Reference:  SS 91278 94773 (as listed in the Humps, with the Trimble GeoXH 6000 survey giving SS 91274 94767)

Bwlch Height:  480.0m (as listed in the Humps with independent LIDAR analysis giving 479.9m)

Bwlch Grid Reference:  SS 9118 9707 (as listed in the Humps with independent LIDAR analysis giving SS 91189 97075)

Drop:  88m (as listed in the Humps with the Trimble GeoXH 6000 summit survey and independent LIDAR bwlch analysis giving 87.5m)

 

Myrddyn Phillips (July 2021)






Mapping Mountains - Hill Reclassifications - Humps

Moel Farlwyd (SH 707 486) – Subhump reclassified to Hump (37th reclassification)


This is the thirty seventh in a series of Hill Reclassification posts that detail hills whose status has either been altered in the listing of the Humps (HUndred Metre Prominences) through map study and / or surveys that I have instigated, or it is the recommendation that their status is altered.

At the summit of Moel Farlwyd (SH 707 486)

Many preceding posts detailing these hill reclassifications are retrospective as they were initiated from studying the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map, or from surveying with the Trimble GeoXH 6000, or from LIDAR analysis, and for this reclassification that affected the Humps the email I posted on the RHB Yahoo Group forum in relation to this hill was dated 01.02.20.

The listing of Humps was published in book format by Lulu in 2009 and entitled More Relative Hills of Britain, its author; Mark Jackson gives credit to a number of people who contributed toward the formation of this list, these include; Eric Yeaman, Alan Dawson, Clem Clements, Rob Woodall, Bernie Hughes, Pete Ridges and others.  When the list was published in book format there were 2987 Humps listed with their criteria being any British hill that has 100m or more of drop, irrespective of their height.  Accompanying the main list is a sub category entitled Subhumps, with the criteria being any British hill that has 90m or more and below 100m of drop.

More Relative Hills of Britain by Mark Jackson

The details for the reclassification appear below:

There has been a reclassification to the listing of the Humps (HUndred Metre Prominences) partly instigated by study of contemporary Ordnance Survey maps conducted by Myrddyn Phillips.

The name the hill is listed by is Moel Farlwyd and it is adjoined to the Moelwynion group of hills, and it is positioned with the A470 road to its west, and has the town of Blaenau Ffestiniog towards the south.

Prior to this reclassification this hill was listed as a Subhump with 98m of drop based on the 577m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps and a bwlch height of 479m based on interpolation of 10m contours between 470m – 480m.

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

The details for this hill were re-assessed using a combination of various scaled Ordnance Survey maps, including the mapping on the OS Maps website.  This is the replacement for OS Get-a-map and has contours at 5m intervals which are proving consistently more accurate compared to the 5m contours that sometimes appear on Ordnance Survey 1:25,000 Explorer maps and used to appear on the online Vector Map Local.  This re-assessment resulted in a recommendation of this hill being reclassified to a Hump with an estimated c 100m – c 101m of drop.

Extract from the OS Maps website

This hill was subsequently surveyed on the 06.02.20 by John Barnard and Graham Jackson using a Leica GS15, resulting in a 575.7m summit height and a 474.3m bwlch height, with these values giving this hill 101.4m of drop.

The listing of the Humps was updated accordingly with the reclassification of this hill from Subhump to Hump and augmented on the 07.02.20.


The full details for the hill are:

Name:  Moel Farlwyd

OS 1:50,000 map:  115

OS 1:25,000 map:  18

Summit Height:  575.7m (converted to OSGM15, Leica GS15)

Summit Grid Reference:  SH 70738 48643 (Leica GS15)

Bwlch Height:  474.3m (converted to OSGM15, Leica GS15)

Bwlch Grid Reference:  SH 71144 48719 (Leica GS15)

Drop:  101.4m (Leica GS15)


Myrddyn Phillips (June 2020)







Mapping Mountains - Hill Reclassifications - Humps

Banc y Graig (SN 699 452) – Hump reclassified to Subhump (36th reclassification)


This is the thirty sixth in a series of Hill Reclassification posts that detail hills whose status has either been altered in the listing of the Humps (HUndred Metre Prominences) through map study and / or surveys that I have instigated, or it is the recommendation that their status is altered.

Banc y Graig (SN 699 452)

Many preceding posts detailing these hill reclassifications are retrospective as they were initiated from studying the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map, or from surveying with the Trimble GeoXH 6000, or from LIDAR analysis, and for this reclassification that affected the Humps the email I posted on the RHB Yahoo Group forum in relation to this hill was dated 09.09.19.

The listing of Humps was published in book format by Lulu in 2009 and entitled More Relative Hills of Britain, its author; Mark Jackson gives credit to a number of people who contributed toward the formation of this list, these include; Eric Yeaman, Alan Dawson, Clem Clements, Rob Woodall, Bernie Hughes, Pete Ridges and others.  When the list was published in book format there were 2987 Humps listed with their criteria being any British hill that has 100m or more of drop, irrespective of their height.  Accompanying the main list is a sub category entitled Subhumps, with the criteria being any British hill that has 90m or more and below 100m of drop.

More Relative Hills of Britain by Mark Jackson

The details for the reclassification appear below:

There has been a reclassification to the listing of the Humps (HUndred Metre Prominences) instigated by study of contemporary Ordnance Survey maps conducted by Myrddyn Phillips.

The name the hill is listed by is Banc y Graig and it is adjoined to the Elenydd group of hills, and it is positioned with the A482 road to its south-west and the A483 road to its south-east, and has the town of Llanbedr Pont Steffan (Lampeter) towards the west north-west and the town of Llanymddyfri (Llandovery) towards the south-east.

Prior to this reclassification this hill was listed as a Hump with 101m of drop based on the 408m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps and a bwlch height of 307m based on the spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which is entitled the Interactive Coverage Map.  This spot height is also shown on Ordnance Survey data that appears on the Magic Maps website.

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

Extract from the Magic Maps website

The details for this hill were re-assessed using a combination of various scaled Ordnance Survey maps, including the mapping on the OS Maps website.  This is the replacement for OS Get-a-map and has contours at 5m intervals which are proving consistently more accurate compared to the 5m contours that sometimes appear on Ordnance Survey 1:25,000 Explorer maps and used to appear on the online Vector Map Local.

Extract from the OS Maps website

Importantly the 307m spot height that appeared on the Vector Map Local and is still shown on the Magic Maps website is positioned at SN 69521 47114.  This position is not where the 5m contours on the OS Maps website indicate the critical bwlch to be positioned and a better representation of this bwlch height and position is c 309m at SN 69555 47145, and when coupled with the 408m summit height gives this hill an estimated c 99m of drop, which is insufficient for it to be reclassified as a Hump, with the summit of this hill subsequently surveyed with the Trimble GeoXH 6000.

The reclassification of this hill from Hump to SubHump status was accepted and its new classification augmented in to the listing of the Humps on the 14.09.19.


The full details for the hill are:

Name:  Banc y Graig

OS 1:50,000 map:  146

OS 1:25,000 map:  187, 199

Summit Height:  408m (spot height as listed in the Humps, with the Trimble GeoXH 6000 survey giving 408.3m)

Summit Grid Reference:  SN 69981 45212 (hand-held GPS via DoBIH as listed in the Humps, with the Trimble GeoXH 6000 survey giving SN 69992 45216)

Bwlch Height:  c 309m (interpolation)

Bwlch Grid Reference:  SN 69555 47145 (interpolation)

Drop:  c 99m (spot height summit and interpolated bwlch)


Myrddyn Phillips (February 2020)



No comments: