Friday, 18 May 2018

Mapping Mountains – Hill Reclassifications – The Fours

Black Hill (SD 865 662) – Four reclassified to 400m Sub-Four

There has been a reclassification to the listing of The Fours due to LIDAR analysis conducted by Aled Williams.  The Fours is the title for the list of 400m hills of England and takes in all English hills at and above 400m and below 500m in height that have a minimum 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.

Accompanying the main list of The Fours are three categories of sub hills, with this hill being reclassified to the 400m Sub-Fours.  The criteria for 400m Sub-Four status are all English hills at and above 400m and below 500m in height that have 20m or more and below 30m of drop. 
Prior to LIDAR analysis this hill was listed with c 30m of drop based on the 468m summit spot height that appears on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map and an estimated col height of c 438m based on col contouring between 430m – 440m on the 1:50,000 and 1:25,000 maps, with the col contours between 440m – 445m on OS Maps, which is the recent replacement for OS Get-a-map.

The name of the hill is Black Hill and it is situated in the Central Pennines and is placed in Region 35, Section 35B, with its Cardinal Hill being Pen y Ghent (SD 838 733).  The hill is positioned with Malham Tarn to its east and has the small town of Settle to its west south-west.

As the summit of the hill is a part of designated open access land it can be approached from most directions, with the nearest public footpath being to the north which gives access from a minor lane to the open access land.

The reclassification of Black Hill to 400m Sub-Four status is due to LIDAR analysis conducted by Aled Williams.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

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

Black Hill

Summit Height:  468.4m

Summit Grid Reference:  SD 86566 66232

Col Height:  440.2m

Col Grid Reference:  SD 86841 66039

Drop:  28.2m

LIDAR image of Black Hill

Therefore, the 468.4m LIDAR analysis for the summit position at SD 86566 66232 and the 440.2m LIDAR analysis for the col position at SD 86841 66039 gives this hill 28.2m of drop, which is insufficient for its continued status as a Four.

The full details for the hill are:

Cardinal Hill:  Pen y Ghent

Summit Height:  468.4m (LIDAR)

Name:  Black Hill

OS 1:50,000 map:  98

Summit Grid Reference:  SD 86566 66232 (LIDAR)

Drop:  28.2m (LIDAR)

For the additions, deletions and reclassifications to The Fours reported on Mapping Mountains since the December 2013 publication of the list by Europeaklist please consult the following Change Registers:

Myrddyn Phillips and Aled Williams (May 2018)

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