Showing posts with label The Fours - Summit Relocations. Show all posts
Showing posts with label The Fours - Summit Relocations. Show all posts

Sunday, 30 August 2020

Mapping Mountains – Summit Relocations – The Fours – The 400m Hills of England


Rushy Knowe (NY 681 820)

There has been a Summit Relocation to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill derived from detail on contemporary maps produced from Ordnance Survey data.


This spreadsheet is being evaluated by a number of people, including Ronnie Bowron, who passed the details of this hill for evaluation.

The criteria for the list that this summit relocation applies to are:

The FoursThe 400m Hills of England.  English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main listing of The Fours are three categories of sub hills, with this hill being listed in the 390m Double Sub-Four category, the criteria for which are all English hills at or above 390m and below 400m in height that have 20m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and the 2nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Rushy Knowe, and it is adjoined to Sighty Crag group of hills, which are situated in the north-eastern part of England (Region 33 Scottish Border to the River Tyne), and it is positioned with a minor road and Kielder Water to its north, and has the village of Bellingham towards the east.

When the 2nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was listed with an estimated c 28m of drop, based on the 397m summit spot height positioned at NY 677 817 and an estimated c 369m col height based on interpolation of 10m contouring between 360m – 370m that appear on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.

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

The details for this hill have now been re-assessed against Ordnance Survey data hosted on the Magic Maps website, and this mapping gives a 398m spot height on the summit area of this hill positioned at NY 681 820.

Extract from the Magic Maps website

This new summit position and interpolation of col contouring were also re-assessed against 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 the estimated col height for this hill being amended to c 371m, with this based on interpolation of 5m contouring between 370m – 375m.

Extract from the OS Maps website

The above detail 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 in a different field, or where a number of potential summit positions are within close proximity and the highest point is not where previously given, or when it is positioned to a different feature such as in a conifer plantation, or when the high point of the hill is placed within a different map contour, or 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 that is judged to be 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 listed summit height of this hill is now 398m and its new position is NY 68108 82036, this position is not given a spot height on the contemporary Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and is approximately 350 metres north-eastward from where the previously listed summit is positioned.


The full details for the hill are:

Group:  Sighty Crag

Name:  Rushy Knowe

OS 1:50,000 map:  80

Summit Height:  398m (spot height)

Summit Grid Reference (new position):  NY 68108 82036 (spot height)

Col Height:  c 371m (interpolation)

Col Grid Reference:  NY 67304 81373 (interpolation)

Drop:  c 27m (spot height summit and interpolated col)


Myrddyn Phillips and Aled Williams (August 2020)



Friday, 14 August 2020

Mapping Mountains – Summit Relocations – The Fours – The 400m Hills of England


Green Side (NT 906 076)

There has been a Summit Relocation to a hill that is listed in the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill confirmed by LIDAR analysis.

This was initiated by Joe Nuttall who produced a summit analysis programme that used LIDAR with an alternative height map (DEM) allowing identification of summits and cols and thereby drops.  The resulting spreadsheet that Joe produced contains over 29600 hills.

This spreadsheet is being evaluated by DoBIH Editors and others, and for this particular hill it was Jim Bloomer who initially assessed its height and that of its adjacent peak via LIDAR analysis.

Myrddyn Phillips then evaluated this hill’s details via LIDAR analysis and confirmed its height and hence its summit relocation and addition as a 390m Sub-Four.

LIDAR image of Green Side (NT 906 076)

The criteria for the list that this summit relocation applies to are:

The FoursThe 400m Hills of England.  English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main listing of The Fours are three categories of sub hills, with this hill being added to the 390m Sub-Four category, the criteria for which are all English hills at or above 390m and below 400m in height that have 30m minimum drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and the 2nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Green Side, and it is adjoined to The Cheviot group of hills, which are situated in the north-eastern part of England (Region 33 Scottish Border to the River Tyne), and it is positioned with a minor road to its south-east and farther afield has the A68 road to its south-west, the B6341 road to its south-east and the A697 road to its east, and has the town of Rothbury towards the east south-east.

When the 2nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was not classified but was listed with an estimated c 17m of drop, based on the 389m summit height adjoined to a triangulation pillar that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map, and an estimated c 372 col height based on interpolation of 5m contouring between 370m – 375m that appear on the OS Maps website.

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

Approximately 1km to the north-east of the triangulation pillar atop Green Side is the hill named Lord’s Seat.  The flush bracket adjoined to this trig pillar is given as 389.534m and positioned at NT 90299 07313 in the OS Trig Database, with its map height given as 389m.  As the map height of Lord’s Seat is 392m it was this hill that was classified as the 390m Sub-Four with c 53m of drop.

However, it was not until LIDAR became available that the details for these two hills 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 for these two hills is given below:


Lord’s Seat:  392.2m at NT 91281 07968 and NT 91282 07966

Green Side:  395.5m at NT 90695 07602


The above detail 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 in a different field, or where a number of potential summit positions are within close proximity and the highest point is not where previously given, or when it is positioned to a different feature such as in a conifer plantation, or when the high point of the hill is placed within a different map contour, or 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 that is judged to be 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.
  
As Green Side is higher than Lord’s Seat the respective cols are swapped and Green Side becomes the 390m Sub-Four.  However, the subsequent drop for Lord’s Seat is sufficient for it to be classified as a 390m Double Sub-Four.

LIDAR image of Green Side and Lord's Seat

Therefore, the summit height produced by LIDAR analysis is 395.5m and this is positioned at NT 90695 07602, this is approximately 400 metres north-eastward from where the triangulation pillar is positioned and approximately 600 metres south-westward from where the old listed summit of Lord’s Seat is positioned.


The full details for the hill are:

Group:  The Cheviot

Name:  Green Side

OS 1:50,000 map:  80

Summit Height:  395.5m (LIDAR)

Summit Grid Reference (new position):  NT 90695 07602 (LIDAR)

Col Height:  339.5m (LIDAR)

Col Grid Reference:  NT 90531 07919 (LIDAR)

Drop:  56.0m (LIDAR)


Myrddyn Phillips and Aled Williams (August 2020)



Sunday, 17 June 2018

Mapping Mountains – Summit Relocations – The Fours


High Hill (SD 833 636)

There has been a Summit Relocation to a hill that is listed in The Fours initiated by LIDAR analysis conducted by Myrddyn Phillips.  The Fours is the title for the list of 400m hills of England and is co-authored by Myrddyn Phillips and Aled Williams with the 2nd edition of the booklet containing this list published by Mapping Mountains Publications on the 24th April 2018.

The criteria for the list that this summit relocation affects are:

English hills at and above 400m and below 500m in height that have 30m minimum drop, accompanying the main list of The Fours are three categories of sub hills, with this hill being classified in the 390m Sub-Fours.  The criteria for 390m Sub-Four status are all English hills at and above 390m and below 400m in height that have 30m minimum drop. 

The name of the hill is High Hill and it is situated in Region 35; The Northern and Central Pennines, Section 35B; The Central Pennines, and is positioned with the B 6480 road to its west which joins the A 65 road to its south south-west, and has the small town of Settle to its west.

As the upper section of the hill is a part of designated open access land an ascent is feasible from most directions, with a public footpath heading west to east and placed to the north of the summit and relatively easy access from a minor road to the south.

The summit area of this hill has a 390m uppermost contour that is given a 398m spot height positioned at SD 83244 63492 on contemporary Ordnance Survey maps, and this is where the summit of the hill was listed in the 1st edition of The Fours when published by Europeaklist in December 2013.

Extract from the Ordnance Survey Interactive Coverage Map hosted on the Geograph website with the summit position circled

The highest land in the 390m ring contour was analysed via LIDAR by Myrddyn Phillips.  The LIDAR (Light Detection & Ranging) technique is highly accurate height data that is now freely available for much of England and Wales. 

The summit height produced by LIDAR analysis is 398.3m and is positioned at SD 83338 63674, this position is not given a spot height on contemporary Ordnance Survey maps, although it and that of the previously listed summit both possess an uppermost 395m ring contour on OS Maps.

LIDAR image of the summit area of High Hill

Therefore, the confirmation of the relocated summit position is at SD 83338 63674 and this is approximately 200 metres north north-east from where the previous listed 398m map heighted summit was given in the 1st edition of The Fours.


The full details for the hill are:

Cardinal Hill:  Pen y Ghent

Summit Height:  398.3m (LIDAR)

Name:  High Hill

OS 1:50,000 map:  98

Summit Grid Reference (New Position):  SD 83338 63674 (LIDAR)  

Drop:  40.2m (LIDAR)


Myrddyn Phillips and Aled Williams (June 2018)