Wednesday, 30 November 2016

Mapping Mountains – Hill Reclassifications – Yr Uchafion


Pt. 637.4m (SO 266 322) - Uchaf reclassifed to 500m Sub-Uchaf

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 of 15m of drop, 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 hill is situated in the Mynyddoedd Duon (Black Mountains) group of hills in the eastern part of the Parc Cenedlaethol Bannau Brycheiniog (Brecon Beacons National Park) in the Region of South Wales (C-3) and is situated on the most easterly of the main elongated ridges of this hill range with Waun Fach (SO 215 299) being its Cardinal Hill, and it is positioned above the small community of Capel-y-ffin to its south-west and the Olchon Valley to its east and the Vale of Ewyas to its south.  The hill can be accessed on good paths from these two valleys or from its south-east or north-west via the Offa’s Dyke Path that follows the ridge crest.

As an appropriate name for this hill is not in the public domain it is being listed under the point (Pt. 637.4m) notation, and its reclassification from an Uchaf to a 500m Sub-Uchaf is due to the analysis of LIDAR data.  LIDAR (Light Detection & Ranging) is highly accurate height data that is now freely available for much of England and Wales, and the hill was first analysed with this data by Joseph Nuttall, independent of this, Aled also analysed LIDAR data using a slightly different method and ascertained the details for this hill’s reclassification.

If Pt. 637.4m does not have the minimum of 15m of drop it would be taken out of the listing of Welsh hills at or over 500m in height that has a minimum of 15m of drop, and has the working title of Yr Uchafion, and if having between 14m and below 15m of drop the hill would be classified as a 500m Sub-Uchaf.

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


Pt. 637.4m

Summit Height:  637.4m (converted to OSGM15, and middle of three equivalent height points)

Summit Grid Reference:  SO 26696 32273

Bwlch Height:  622.7m (converted to OSGM15)

Bwlch Grid Reference:  SO 26711 32628

Drop:  14.7m


As the stated philosophy for our co-authored lists is to take the most accurate data available on any given day, and as Ordnance Survey map data uses a 637m summit spot height attained from an aerial survey that has a prescribed margin of uncertainty of +/- 3m applicable to it and as the previously listed bwlch height is based on contour interpolation we are taking the LIDAR data for the height details of this hill until a more accurate survey can take place.  LIDAR data is quoted as having a prescribed margin of uncertainty of +/- 0.15m. 

Therefore, the 637.4m LIDAR data produced for the summit position at SO 26696 32273 and the 622.7m LIDAR data produced for the bwlch position at SO 26711 32628 is insufficient for this hill to retain its Uchaf status, and therefore it is reclassified to a 500m Sub-Uchaf with 14.7m of drop, and therefore Pt. 637.4m is taken out of the main listing of Yr Uchafion and the list will be updated accordingly.

This now revises the total in Yr Uchafion which will be updated accordingly and the hill is now listed as a 500m Sub-Uchaf.


The full details for the hill are:

Cardinal Hill:  Waun Fach

Summit Height:  637.4m (converted to OSGM16, LIDAR data, and middle of three equivalent height points)

Name:  Pt. 637.4m

OS 1:50,000 map:  161

Summit Grid Reference:  SO 26696 32273 
  
Drop:  14.7m (converted to OSGM15, LIDAR data)


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


UCHAF ADDITIONS




UCHAF RECLASSIFICATIONS



Pt. 637.4m (SO 266 322) Uchaf reclassified to 500m Sub-Uchaf with 14.8m of drop.



UCHAF DELETIONS




Pt. 637.4m now reclassified from an Uchaf to a 500m Sub-Uchaf

Myrddyn Phillips and Aled Williams (November 2016)








Tuesday, 29 November 2016

Articles - Internet


Introduction

The articles listed below all appear on the Internet and have either been written by myself, or they have been written in conjunction with input from other people or are directly related to things that I have been involved in.

The listing below includes brief details relating to each article and hyperlinks to their source, with the articles listed chronologically in receding order.




2016, published 25.11.16 by UKHillwalking


Listing the reclassifications to the Nuttalls list since first publication in 1989 and 1990.





2016, published 09.11.16 by UKHillwalking


Rob Woodall’s completion of the Welsh, English and Manx hills at or above 300m.





2016, published 14.09.16 by Geographical


The official online magazine for the Royal Geographical Society covers the elevation of Calf Top to 2,000ft (609.6m) status.




2016, published 08.09.16 on the Ordnance Survey blog


Calf Top reaches the height of 2,000ft (609.6m – just!) through the new geoid model employed by the Ordnance Survey.





2016, published 06.09.16 by UKHillwalking


The elevation of Calf Top to the ranks of 2,000fts.





2016, published 06.09.16 by Grough


Calf Top enters the ranks of Gewitts and Nuttalls as it reaches the height of 2,000ft (609.6m) for all of 6mm.





2015, published 02.10.15 by Grough


Boo Smith’s article reporting the Ebury Press publication of Leland Carlson’s book ‘Dull Men of Great Britain’.





2015, published 29.09.15 by the BMC


Hanna Lindon interview with Graham Jackson on the recent survey results of Creag na Caillich and Mullach Coire nan Cisteachan which confirmed previous surveys conducted by Alan Dawson.




2015, published 11.09.15 by UKHillwalking


Confirmation of previous surveys conducted by Alan Dawson with Creag na Caillich demoted and Mullach Coire nan Cisteachan promoted to the ranks of Munro Tops.





2015, published 11.09.15 by Grough


The demotion of Creag na Caillich and the promotion of Mullach Coire nan Cisteachan to the Munro Tops confirming previous surveys conducted by Alan Dawson.





2015, published 03.08.15 by Grough


Surveying the hill listed by John and Anne Nuttall as Moelwyn Mawr North Ridge Top.





2015, published 03.08.15 by UKHillwalking


The loss of Moelwyn Mawr North Ridge Top from the list of Nuttalls.





2015, published 09.06.15 by UKHillwalking


Leading up to the survey of Meall Gaineimh.





2015, published summer 2015 by The King’s School Chester


King’s School Chester kindly sent me photographs of Arthur St George Walsh to accompany The History of Welsh Hill Lists article that appeared on the Mapping Mountains site, and followed this up with their own piece on their former teacher.




2015, published 13.04.15 by Grough


The publication of the co-authored list with Aled Williams of Y Pellennig – The Remotest Hills of Wales.





2015, published 13.04.15 by UKHillwalking


An article on the publication of Y Pellennig – The Remotest Hills of Wales which is co-authored with Aled Williams.





2014, published 14.10.14 on the Ordnance Survey blog


The re-surveying of Snowdon with Mark Greaves; Geodetic Analyst at Ordnance Survey was filmed for an ITV Wales programme entitled ‘Climbing New Heights’.





2014, published 14.10.14 by UKHillwalking


Reporting the re-survey of Snowdon with Mark Greaves; Geodetic Analyst representing the Ordnance Survey.





2014, published 13.10.14 by Grough


Reporting the re-survey of Wales’ highest mountain.





2014, published 22.08.14 by UKHillwalking


Detailing the first accurate summit survey of the highest point of Y Berwyn, a mountain that at one time did not exist on Ordnance Survey maps.





2014, published 29.06.14 by Grough


More than 25 years ago Bill Wright reported that the Ordnance Survey had ‘missed’ a mountain from their maps, and the missing mountain proved to be the highest point of the Berwyn.





2014, published 10.03.14 on the Korec blog


Reporting on when a Trimble encountered a hill named Whimble.




2013, published 16.12.13 by UKHillwalking


The publication of The Fours – The 400m Hills of England, which is a list co-authored with Aled Williams.





2013, published 15.12.13 by Grough


The Fours, a co-authored list with Aled Williams detailing the 400m hills of England.





2013, published 15.11.13 on the Ordnance Survey blog


Surveying Knight’s Peak and the Basteir Tooth on the Cuillin of Skye.





2013, published 13.11.13 by UKHillwalking


Article on the Knight’s Peak and Basteir Tooth survey results.





2013, published 13.11.13 by Grough


Bob Smith reporting the consequences of the Knight’s Peak survey.





2013, published 19.08.13 on the Ordnance Survey blog


Laying the scene for the upcoming survey of Knight’s Peak.





2013, published 14.08.13 by Grough


Bob Smith reporting the upcoming survey of Knight’s Peak.





2013, published 04.06.13 by UKHillwalking


An article on the publication of Y Pedwarau – The 400m Hills of Wales which is co-authored with Aled Williams.





2013, published 27.05.13 on BBC Wales News


BBC Wales reports on the publication of Y Pedwarau which is co-authored with Aled Williams.




2013, published 22.05.13 by Grough


The publication of Y Pedwarau – The 400m Hills of Wales, a co-authored list with Aled Williams.





2013, published 07.05.13 on the Ordnance Survey blog


A report on the survey of Tal y Fan filmed for BBC Breakfast with Mark Greaves representing the Ordnance Survey.





2013, published 04.04.13 by UKHillwalking


Dan Bailey reports on the reclassification of Thack Moor.





2013, published 03.04.13 on the Ordnance Survey blog


The elevation of Thack Moor to the ranks of 2,000ft mountains.





2013, published 03.04.13 by Grough


Bob Smith’s article on Thack Moor joining the ranks of 2,000ft (609.6) Hewitts and Nuttalls.





2012, published 08.11.12 on the Ordnance Survey blog


The survey of Buidhe Bheinn and Sgurr a’ Bhac Chaolais to separate the infamous twin topped Corbett.





2012, published 08.11.12 by Grough


Bob Smith reporting on the survey of Buidhe Bheinn and Sgurr a’ Bhac Chaolais to separate the infamous twin topped Corbett.





2012, published 06.09.12 by Grough


Dave Hewitt reports on the reclassification of Beinn a’ Chlaidheimh.





2012, published 14.05.12 in the Marhofn magazine


I’d corresponded with ‘Clem’ Clements for many years and was fortunate to visit him shortly before he died.




2011, published 13.08.11 by Grough


Bob Smith reports on the ramifications of the Beinn a’ Chlaidheimh survey result.




2011, published 21.05.11 by Grough


Bob Smith reporting on whether the recognised county top of Nottinghamshire stands up to scrutiny?





2011, published 16.04.11 by Grough


Bob Smith reporting on the inclusion of Kirkby Fell in to the ranks of Deweys.





2011, published 01.04.11 on the Ordnance Survey blog


Alan Dawson explains the joys of ‘Hole Bagging’.





2011, published 01.04.11 by Grough


Celebrating the start of April with a new list of holes compiled by Alan Dawson.





2010, published 21.09.10 by the Snowdonia National Park Authority


Reporting that Wales now has five mountains higher than 1,000m.





2010, published 21.09.10 by Grough


Liz Roberts reporting on the inclusion of Glyder Fawr in to the ranks of ‘Super Mountains’.





2010, published 07.09.10 by Grough


John McHale’s article on the impending announcement of the Glyder Fawr survey result.





2010, published 29.06.10 on the Ordnance Survey blog


Would one of the most iconic mountains in Wales lose its 3,000ft status?





2010, published 26.06.10 by the Snowdonia Society


The Snowdonia Society’s announcement of the survey result of Tryfan.





2010, published 24.06.10 by Grough


John McHale reporting on the survey result of Tryfan.





2010, published 19.06.10 by Grough


Bob Smith’s article reporting the imminent survey of Tryfan.





2010, published 15.06.10 on the Ordnance Survey blog


An article of the impending survey of Tryfan.





2010, published 15.03.10 by Grough


Liz Roberts reporting on the announcement that Tryfan is to be accurately surveyed.





2010, published 09.03.10 by the Snowdonia Society


The Snowdonia Society’s announcement that Tryfan is to be re-surveyed.





2009, published 11.09.09 by Grough


Dave Hewitt’s article on The Munro Society’s press conference announcement on the survey results of the Munro heightings.





2009, published 10.09.09 by Grough


John McHale reports of the Sgurr nan Ceannaichean reclassification.




2009, published 08.09.09 by Grough


Dave Hewitt’s article on the imminent announcement from The Munro Society’s heightings.





2009, published 24.08.09 by Grough


John McHale’s article on the imminent announcement of the survey results from The Munro Society’s heightings.





2009, published 22.08.09 by Grough


Bob Smith reporting on the impending survey result of Milk Hill and Tan Hill to confirm the county of Wiltshire’s high point due to be broadcast on BBC’s Countryfile the following day.





2009, published 09.07.09 by the Snowdonia Society


The inclusion of Castell y Gwynt into the ranks of Welsh 3,000fts.





2009, published 15.04.09 by Grough


The inclusion of Mynydd y Cwm and the exclusion of Raw Head from the Marilyn ranks.





2008, published 29.08.08 by Grough


Bob Smith’s article on the announcement of the elevation of Mynydd Graig Goch to 2,000ft (609.6m) mountain status.






My thanks to John Barnard, Graham Jackson, Aled Williams and Mark Trengove for input in to many of the articles, and to Bob Smith at Grough, Dan Bailey at UKHillwalking,  and Melanie Osborne and Andy Steggall at Ordnance Survey for their continued support and to Paul Beauchamp at Ordnance Survey for past support.