Wednesday 25 October 2023

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


Pt. 466.7m (SK 034 589) 

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 LIDAR analysis conducted by Myrddyn Phillips. 

LIDAR image of Pt. 466.7m (SK 034 589)

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 list are three categories of sub hills, with this hill being included in the 400m Sub-Four category, the criteria for which are all English hills at or above 400m and below 500m 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 hill is being listed by the point (Pt. 466.7m) notation, and it is adjoined to the Axe Edge group of hills, which are situated in the Peak District, and it is positioned with minor roads to its north-east, west and south, the A53 road farther to its west and the B5053 road to its south-east, and has the town of Leek towards the west south-west.

When the 1st edition of the The Fours was published by Europeaklist in December 2013, this hill was listed as a 400m Sub-Four with 29m of drop, based on the 467m summit spot height that is positioned at SK 035 589 and appears on the Ordnance Survey 1:25,000 Explorer map and the 438m col spot height that appeared on the Ordnance Survey Vector Map Local hosted on the Geograph website and which was entitled the Interactive Coverage Map.  This is also the position the summit of this hill was listed as when the 2nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018. 

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.

LIDAR analysis gives the highest ground on this hill as 466.9m positioned at SK 03494 58988.  However, this is a part of a raised field boundary and protocols dictate that as this is deemed a relatively recent man-made construct such ground is discounted from the height of a hill. 

LIDAR summit image of Pt. 466.7m (SK 034 589)

The height produced by LIDAR analysis to the natural summit of this hill is 466.7m and is positioned at SK 03488 58962, 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 high point of the hill is found to be positioned; in a different field, to a different feature such as in a conifer plantation,  within a different map contour, to a different point where a number of potential summit positions are within close proximity, 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 or covered reservoir 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 height produced by LIDAR analysis to the natural summit of this hill is 466.7m and is positioned at SK 03488 58962, 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 32 metres south-westward from where the high point of the raised field boundary is positioned. 

 

The full details for the hill are:

Group:  Axe Edge

Name:  Pt. 466.7m

OS 1:50,000 map:  119

Summit Height:  466.7m (LIDAR)

Summit Grid Reference (New Position):  SK 03488 58962 (LIDAR)

Col Height:  439.4m (LIDAR)

Col Grid Reference:  SK 03455 60210 (LIDAR)

Drop:  27.3m (LIDAR)

 

Myrddyn Phillips and Aled Williams (October 2023)

 

  

No comments: