Sunday, 19 February 2017

Change Register - The 500-Metre Tops of Ireland - 490m Subs


Change Register

The 500-Metre Tops of Ireland

490m Subs


The 500-Metre Tops of Ireland are the Irish hills at or above 500m and below 609.6m (2,000ft) in height that have a minimum drop of 30m.  The list is co-authored by Michael Dewey and Myrddyn Phillips with each having produced a version of the list independent of the other.  Michael’s list originated in 1998 and comprised 186 hills, whilst Myrddyn’s list originated in 2000 and comprised 191 hills with a further 29 hills listed in a sub list entitled ‘Hills that need on the spot surveying with the prospect of being future additions’, this sub list forms the basis of the 500m Subs that now accompanies the main P30 list.

The list produced by Myrddyn was sent to a number of people including Michael Dewey and the Mountaineering Council of Ireland (now named Mountaineering Ireland).  Having produced versions of the same list the two authors combined each and decided to produce one co-authored list.  Data were re-evaluated and the updated co-authored list was sent to the Mountaineering Council of Ireland and later formed the lower height band of the list that appeared on the fledging MountainViews website in 2002, this list was later named the Arderins in 2009, with the higher height band of this list using data from the late Joss Lynam’s 600m Irish list.    

The 500-Metre Tops of Ireland listing was next fully re-evaluated with assistance from Jim Bloomer prior to it being published on the Hill Bagging website on 1st June 2011, and it was then published in the downloadable Access and Excel versions (v12.0) of the Database of British and Irish Hills (DoBIH) on 27th November 2011.  During this process the original sub list was also fully re-evaluated and appeared in the Hill Bagging publication entitled subMyrddynDewey, this sub list is referred to as the 500m Subs in the Change Registers published on Mapping Mountains.

However, it wasn’t until the Hill Bagging publication and the subsequent Database of British and Irish Hills (DoBIH) publication that the listing included two other sub categories; the 490m Subs and the 490m Double Subs and this Change Register details those hills that are, or have been listed within the 490m Subs category.  These two sub categories are not officially tied to The 500-Metre Tops of Ireland list on either the Hill Bagging or the DoBIH publication, but these data were sourced from The 400-Metre Tops of Ireland list compiled by Myrddyn Phillips and subsequently duplicated by MountainViews and renamed The Carns.  As these data are officially a part of The 500-Metre Tops of Ireland list, the hills incorporated are documented in this Change Register.  The 490m Subs comprise all Irish hills that fail to meet The 500-Metre Tops of Ireland qualification by 10m or less of height, these are the hills that are 490m or more and below 500m in height that have a minimum 30m of drop.

Although the criteria has remained the same The 500-Metre Tops of Ireland list has changed greatly since its first publication with the advent of independent surveyors enabling greater accuracy for numerical data, and the meticulous research conducted by Paul Tempan and incorporated by MountainViews, the listing also now incorporates three Sub categories, the 500m Subs, the 490m Subs which this Change Register details and the 490m Double Subs.

It seems fitting that the list of The 500-Metre Tops of Ireland – 490m Subs should now benefit from a detailed Change Register, and although the compilation to this sub list took place when the data were re-evaluated prior to publication on the Hill Bagging website in 2011, it is prudent for this Change Register to initially detail the changes to the list since this publication.

The Change Register to The 500-Metre Tops of Ireland – 490m Subs appears below with the reclassifications to the list being detailed chronologically in receding order.




Change Register

The 500-Metre Tops of Ireland

490m Subs






As of yet there are no reclassifications to this sub list since June 2011 publication by Hill Bagging.




27th November 2011 – Database of British and Irish Hills publishes The 500-Metre Tops of Ireland. 

The 500-Metre Tops of Ireland – 490m Subs total confirmed as 22.




1st June 2011 – Hill Bagging publishes The 500-Metre Tops of Ireland. 

The 500-Metre Tops of Ireland – 490m Subs total confirmed as 22.






Michael Dewey and Myrddyn Phillips (February 2017)

  




Saturday, 18 February 2017

Mapping Mountains – Hill Reclassifications – Y Trechol – The Dominant Hills of Wales



Bodlondeb Wood (SH 779 781)

There has been an addition to the listing of Y Trechol – The Dominant Hills of Wales due to detail included on the Ordnance Survey enlarged mapping hosted on the Geograph website.  This has resulted in the hill being added to the Dominant list.  With the criteria for inclusion to this list being those Welsh P30 hills whose prominence equal or exceed half that of their absolute height.

The details relating to this hill’s inclusion as a Dominant Hill are retrospective as it appeared in the Carneddau group of hills when published on Mapping Mountains on the 17th December 2015.

Prior to this hill’s inclusion as a Dominant Hill it had remained unclassified outside of its recent inclusion as a Tump, as Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map detail only gave the hill as having an uppermost 50m ring contour and bwlch contouring between 20m – 30m, with a drop of c 27m based on an estimated summit height of c 53m and an estimated bwlch height of c 26m.

The hill is in the Carneddau group of hills and is placed in the Region of North Wales (Region A, Sub-Region A1) and is situated on the outskirts of Conwy with the Afon Conwy to its immediate north and east.

If wanting to visit the hill it can be accessed relatively easily with public parking available next to where the Offices are marked to the south of the summit on Ordnance Survey maps.  There are a number of paths marked on the map that head up to, or contour around the summit, and as the name of the hill suggests it is part of a wood which consists of deciduous trees.

The name of the hill is Bodlondeb Wood and it is included as a Dominant Hill as the Ordnance Survey enlarged map hosted on the Geograph website has contours at 5m intervals giving the hill an uppermost contour of 55m and bwlch contouring between 20m – 25m.  Therefore the summit is estimated as being c 57m high and the bwlch estimated as being c 23m high, with these values giving this hill c 34m of drop and 59.65% Dominance.


The full details for the hill are:

Group:  Carneddau

Name:  Bodlondeb Wood

Dominance:  59.65%

OS 1:50,000 map:  115

Summit Grid Reference:  SH 77923 78114

Summit Height:  c 57m

Drop Summit to Bwlch:  c 34m

Drop Bwlch to ODN:  c 23m 


Myrddyn Phillips (February 2017)



Thursday, 16 February 2017

Change Register - The 500-Metre Tops of Ireland - 500m Subs


Change Register

The 500-Metre Tops of Ireland

500m Subs


The 500-Metre Tops of Ireland are the Irish hills at or above 500m and below 609.6m (2,000ft) in height that have a minimum drop of 30m.  The list is co-authored by Michael Dewey and Myrddyn Phillips with each having produced a version of the list independent of the other.  Michael’s list originated in 1998 and comprised 186 hills, whilst Myrddyn’s list originated in 2000 and comprised 191 hills with a further 29 hills listed in a sub list entitled ‘Hills that need on the spot surveying with the prospect of being future additions’, this sub list forms the basis of the 500m Subs that now accompanies the main P30 list.

The list produced by Myrddyn was sent to a number of people including Michael Dewey and the Mountaineering Council of Ireland (now named Mountaineering Ireland).  Having produced versions of the same list the two authors combined each and decided to produce one co-authored list.  Data were re-evaluated and the updated co-authored list was sent to the Mountaineering Council of Ireland and later formed the lower height band of the list that appeared on the fledging MountainViews website in 2002, this list was later named the Arderins in 2009, with the higher height band of this list using data from the late Joss Lynam’s 600m Irish list.    

The compilation originally sent to the Mountaineering Council of Ireland included a sub list entitled ‘Hills that need on the spot surveying with the prospect of being future additions.’  This sub list comprised all hills identified from map study that were at or above 500m and below 609.6m (2,000ft) in height and if surveyed for drop stood a chance of qualifying for the main P30 list.  At the time of compilation the spot heights on Ordnance Survey of Ireland and Ordnance Survey of Northern Ireland maps were taken at face value as the margin of uncertainty applicable to the surveying method that ascertained them was unknown at the time.  Therefore if a hill was given a drop value of 29m from its summit and col spot heights it was not included in this ‘Hills to be surveyed’ sub list as it was deemed not to warrant a survey for inclusion into the main P30 list as the map had given it 29m of drop.  This sub list has now been standardised and comprises all Irish hills that are at or above 500m and below 609.6m (2,000ft) in height and have 20m or more and below 30m of drop, the name of this sub list is the 500m Subs.

The 500-Metre Tops of Ireland listing was next fully re-evaluated with assistance from Jim Bloomer prior to it being published on the Hill Bagging website on 1st June 2011, and it was then published in the downloadable Access and Excel versions (v12.0) of the Database of British and Irish Hills (DoBIH) on 27th November 2011.  During this process the original sub list was fully re-evaluated and appeared in the Hill Bagging publication entitled subMyrddynDewey, this sub list is referred to as the 500m Subs in this Change Register.

Although the criteria has remained the same the list has changed greatly since its first publication with the advent of independent surveyors enabling greater accuracy for numerical data, and the meticulous research conducted by Paul Tempan and incorporated by MountainViews, the listing also now incorporates three Sub categories, the 500m Subs which this Change Register details, the 490m Subs and the 490m Double Subs.

It seems fitting that the list of The 500-Metre Tops of Ireland – 500m Subs should now benefit from a detailed Change Register, and although the majority of updates to this sub list took place when the data were re-evaluated prior to publication on the Hill Bagging website in 2011, it is prudent for this Change Register to initially detail the changes to the list since this publication.

The Change Register to The 500-Metre Tops of Ireland – 500m Subs appears below with the reclassifications to the list being detailed chronologically in receding order.





Change Register

The 500-Metre Tops of Ireland

500m Subs





Pigeon Rock Mountain North Top    534m at J 261 250

This hill’s inclusion in the 500m Subs list was announced on the Mapping Mountains site on 24.08.16, the hill was not previously listed in the 500m Subs as assessment of contour interpolation had given it only c 19m of drop, just under the 20m minimum drop required to qualify for this sub list.  However, upon Jim Bloomer’s suggestion to re-assess this hill’s data it was included in the 500m Subs and listed with a 534m summit height based on the spot height on the Ordnance Survey of Northern Ireland 1:50,000 Discoverer Series map 29, the Harvey map and the Mournes Activity map, and an interpolated col height of c 514m, which gave this hill a listed drop of c 20m, this is sufficient for this hill’s inclusion in this sub category.  The 500-Metre Tops of Ireland – 500m Subs total increases by one and confirmed as 58.




Knocknaveacal North Top    509.1m at V 74438 56269

This is the first hill to be reclassified to the 500m Subs list from the main P30 list, and its reclassification was announced on the Mapping Mountains site on 06.11.15, the hill was previously listed as a 500m P30 based on the 513m summit spot height that appears on the Ordnance Survey of Ireland 1:50,000 Discovery Series map 84 and an interpolated col height of c 482m, which gave this hill a listed drop of c 31m.  The hill was subsequently surveyed by John Fitzgerald on the 30.05.15 with a Trimble GeoXH 6000 resulting in a 509.1m summit height and 482.6m col height, the surveyed drop of 26.5m is insufficient for this hill’s retention in The 500-Metre Tops of Ireland list and it is now reclassified to a 500m SubThe 500-Metre Tops of Ireland – 500m Subs total increases by one and confirmed as 57.




27th November 2011 – Database of British and Irish Hills publishes The 500-Metre Tops of Ireland. 

The 500-Metre Tops of Ireland – 500m Subs total confirmed as 56.




1st June 2011 – Hill Bagging publishes The 500-Metre Tops of Ireland. 

The 500-Metre Tops of Ireland – 500m Subs total confirmed as 56.







Michael Dewey and Myrddyn Phillips (February 2017)




Wednesday, 15 February 2017

Mapping Mountains – Hill Reclassifications – Yr Uchafion


Blaen y Clawdd Du (SN 878 752)

There has been a new entry to the listing of Yr Uchafion instigated from analysis of LIDAR data by Aled Williams.  Yr Uchafion is the draft title for a list of the Welsh 500m P15s that takes in all hills in Wales at or above 500m that have a minimum drop of 15m, the list is a joint compilation with Aled Williams.  Details relating to this list were published on the Mapping Mountains site in November 2015.

The listing of Yr Uchafion includes three sub lists; the 500m Sub-Uchaf, 490m Sub-Uchaf and the Double Sub-Uchaf category.  The classification of this hill is from unclassified to Uchaf, as the hill was previously catalogued with insufficient drop even to attain 500m Sub-Uchaf status.

The hill is situated in the Elenydd group of hills with its Cardinal Hill being Draws Drum (SN 790 811) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2).  The hill is situated with the small community of Llangurig to the north-east and is positioned between the stream valleys of the Afon Elan to the south and the Nant y Trafel Gwyn which flows into the Nant y Dernol to the east.

The hill can be accessed from a forestry road to its north, although this may require a bit of tree bashing to reach its high point unless the track is left for open hillside at the northerly connecting bwlch, or it can be accessed from the south-west where a narrow mountain road gives the opportunity of starting the ascent from approximately 390m high.

The hill was previously catalogued with 13m of drop and therefore thought of as being unclassified, this value was based on detail from Ordnance Survey maps, with the 1:50,000 Landranger, the 1:25,000 Explorer and the enlarged map hosted on the Geograph website all giving a summit spot height of 517m, with the latter map also giving a bwlch spot height of 504m.

The name of the hill is Blaen y Clawdd Du and its classification as an Uchaf is due to analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.

Aled’s analysis of LIDAR data gives the hill the following details:


Blaen y Clawdd Du

Summit Height:  516.8m

Summit Grid Reference:  SN 87845 75282

Bwlch Height:  501.2m

Bwlch Grid Reference:  SN 87916 75115

Drop:  15.6m


Therefore, the 516.8m LIDAR data produced for the summit position at SN 87845 75282 and the 501.2m LIDAR data produced for the bwlch position at SN 87916 75115 gives this hill 15.6m of drop which is sufficient for it to be included as an Uchaf  as its drop value is more than the minimum of 15m required.


The full details for the hill are:

Cardinal Hill:  Draws Drum

Summit Height:  516.8m (LIDAR data)

Name:  Blaen y Clawdd Du

OS 1:50,000 map:  135, 136, 147

Summit Grid Reference:  SN 87845 75282 
  
Drop:  15.6m (LIDAR data)


This now brings the overall total for Yr Uchafion / The Welsh 500m P15s to 629 hills with the overall total for the 500m Sub-Uchaf category remaining at 26.

The additions, reclassifications and deletions to Yr Uchafion / The Welsh 500m P15s reported on Mapping Mountains are ills of wales as follows:



UCHAF ADDITIONS





Blaen y Clawdd Du (LIDAR data) (SN 878 752) added as an Uchaf with 15.6m of drop




UCHAF RECLASSIFICATIONS









UCHAF DELETIONS







Myrddyn Phillips and Aled Williams (February 2017)

Monday, 13 February 2017

Change Register - The 500-Metre Tops of Ireland


Change Register

The 500-Metre Tops of Ireland


The 500-Metre Tops of Ireland are the Irish hills at or above 500m and below 609.6m (2,000ft) in height that have a minimum drop of 30m.  The list is co-authored by Michael Dewey and Myrddyn Phillips with each having produced a version of the list independent of the other.  Michael’s list originated in 1998 and comprised 186 hills, whilst Myrddyn’s list originated in 2000 and comprised 191 hills with a further 29 hills listed in a sub list entitled ‘Hills that need on the spot surveying with the prospect of being future additions’, this sub list forms the basis of the 500m Subs that now accompanies the main P30 list.

The list produced by Myrddyn was sent to a number of people including Michael Dewey and the Mountaineering Council of Ireland (now named Mountaineering Ireland).  Having produced versions of the same list the two authors combined each and decided to produce one co-authored list.  Data were re-evaluated and the updated co-authored list was sent to the Mountaineering Council of Ireland and later formed the lower height band of the list that appeared on the fledging MountainViews website in 2002, this list was later named the Arderins in 2009, with the higher height band of this list using data from the late Joss Lynam’s 600m Irish list.    

The 500-Metre Tops of Ireland listing was next fully re-evaluated with assistance from Jim Bloomer prior to it being published on the Hill Bagging website on 1st June 2011, and it was then published in the downloadable Access and Excel versions (v12.0) of the Database of British and Irish Hills (DoBIH) on 27th November 2011. 

Although the criteria has remained the same the list has changed greatly since its first publication with the advent of independent surveyors enabling greater accuracy for numerical data, and the meticulous research conducted by Paul Tempan and incorporated by MountainViews, the listing also now incorporates three Sub categories, the aforementioned 500m Subs, the 490m Subs and the 490m Double Subs.

It seems fitting that the list of The 500-Metre Tops of Ireland should now benefit from a detailed Change Register, and although the majority of updates to this list took place when the two versions were originally combined in 2000, it is prudent for this Change Register to initially detail the changes to the list since the 2011 publication by the Hill Bagging website.

The Change Register to The 500-Metre Tops of Ireland appears below with the reclassifications to the main P30 list being detailed chronologically in receding order.




Change Register

The 500-Metre Tops of Ireland





Knocknaveacal North Top    509.1m at V 74438 56269

The first hill to be reclassified from the main P30 list to the 500m Subs list, and its reclassification was announced on the Mapping Mountains site on 06.11.15, the hill was previously listed as a 500m P30 based on the 513m summit spot height that appears on the Ordnance Survey of Ireland 1:50,000 Discovery Series map 84 and an interpolated col height of c 482m, which gave this hill a listed drop of c 31m.  The hill was subsequently surveyed by John Fitzgerald on the 30.05.15 with a Trimble GeoXH 6000 resulting in a 509.1m summit height and 482.6m col height, the surveyed drop of 26.5m is insufficient for this hill’s retention in The 500-Metre Tops of Ireland list and it is now reclassified to a 500m SubThe 500-Metre Tops of Ireland total decreases by one and confirmed as 201.




27th November 2011 – Database of British and Irish Hills publishes The 500-Metre Tops of Ireland. 

The 500-Metre Tops of Ireland total confirmed as 202.




1st June 2011 – Hill Bagging publishes The 500-Metre Tops of Ireland. 

The 500-Metre Tops of Ireland total confirmed as 202.






Michael Dewey and Myrddyn Phillips (February 2017)



Sunday, 12 February 2017

Mapping Mountains – Hill Reclassifications – Yr Uchafion



Cefn Cwm Coel (SN 891 647)

There has been a reclassification to the listing of Yr Uchafion instigated from analysis of LIDAR data by Aled Williams.  Yr Uchafion is the draft title for a list of the Welsh 500m P15s that takes in all hills in Wales at or above 500m that have a minimum drop of 15m, the list is a joint compilation with Aled Williams.  Details relating to this list were published on the Mapping Mountains site in November 2015.

The listing of Yr Uchafion includes three sub lists; the 500m Sub-Uchaf, 490m Sub-Uchaf and the Double Sub-Uchaf category.  The reclassification of this hill is from Uchaf to 500m Sub-Uchaf, with the criteria for this sub category being all Welsh hills at or above 500m in height that have 14m or more and below 15m of drop.

The hill is situated in the Elenydd group of hills with its Cardinal Hill being Carn yr Hyrddod (SN 790 704) and is placed in the Region of Mid and West Wales (Region B, Sub-Region B2).  The hill is situated with the small community of the Elan Village to its east and is positioned above the Claerwen Reservoir to its west and the Graig-ddu Reservoir to its east.

The hill can be accessed from its east south-east, starting from a picnic place where a public footpath heads west through conifer and then deciduous woodland contouring round the south-western part of the Graig-ddu Reservoir.  A track then leads up the lower slopes of the hill to open access land and a faint path marked on the Ordnance Survey 1:25,000 Explorer map then heads toward the summit.

The hill was listed as an Uchaf with 15m of drop which is the minimum required for inclusion in the main list, this was based on detail from Ordnance Survey maps, with the 1:50,000 Landranger, the 1:25,000 Explorer and the enlarged map hosted on the Geograph website all giving a summit spot height of 504m, with the latter map also giving a bwlch spot height of 489m.

The name of the hill is Cefn Cwm Coel and its reclassification from an Uchaf to a 500m Sub-Uchaf is due to analysis of LIDAR data by Aled Williams.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales.  As LIDAR data does not cover this hill’s summit, only the bwlch data can be analysed.

Aled’s analysis of LIDAR data gives the hill the following details:


Cefn Cwm Coel

Summit Height:  504m

Summit Grid Reference:  SN 89101 64730

Bwlch Height:  489.6m (LIDAR data)

Bwlch Grid Reference:  SN 88436 65371

Drop:  14m (LIDAR data for bwlch)


Therefore, the 504m summit spot height on Ordnance Survey maps at SN 89101 64730 and the 489.6m LIDAR data produced for the bwlch position at SN 88436 65371 gives this hill 14m of drop which is insufficient for it to retain its Uchaf status as its drop is below the minimum of 15m required.


The full details for the hill are:

Cardinal Hill:  Carny yr Hyrddod

Summit Height:  504m

Name:  Cefn Cwm Coel

OS 1:50,000 map:  147

Summit Grid Reference:  SN 89101 64730 
  
Drop:  14m (LIDAR data for bwlch)


This now brings the overall total for Yr Uchafion / The Welsh 500m P15s to 628 hills and the overall total for the 500m Sub-Uchaf category to 26.

The additions, reclassifications and deletions to Yr Uchafion / The Welsh 500m P15s reported on Mapping Mountains are ills of wales as follows:



UCHAF ADDITIONS








UCHAF RECLASSIFICATIONS





Cefn Cwm Coel (LIDAR data for bwlch) (SN 891 647) Uchaf reclassified to 500m Sub-Uchaf with 14m of drop




UCHAF DELETIONS






Myrddyn Phillips and Aled Williams (February 2017)