Mapping Mountains – Significant Height Revisions – The Fours – The 400m Hills of England

 

Soil Hill (SE 076 313) 

There has been a Significant Height Revision 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 Soil Hill (SE 076 313)

The criteria for the list this height revision affects are:

The Fours – The 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, the 400m Sub-Four category, the 390m Sub-Four category and the 390m Double Sub-Four category.  The list is co-authored by Myrddyn Phillips and Aled Williams and the 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

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

The name the hill is listed by is Soil Hill, and it is adjoined to the Pendle group of hills, which are situated in the southern Pennines, and it is positioned with the B6145 road to its north north-west, the A629 road to its west, a minor road to its south and the A644 road to its north-east, and has the town of Denholme towards the north. 

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

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was listed with a 402m summit height, with an accompanying note stating; 402m summit height taken from the 1,320.4ft (402.46m) surface height on the OS Six-Inch map published in 1852. 

Extract from the Ordnance Survey series of Six-Inch maps

However, due to quarrying activity the height of this hill was in flux.  Therefore, 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 summit image of Soil Hill (SE 076 313)

LIDAR analysis gives the highest ground on this hill as 408.8m positioned at SE 07680 31368, and this comes within the parameters of the Significant Height Revisions used within this page heading, these parameters are:

The term Significant Height Revisions applies to any listed hill whose interpolated height and Ordnance Survey or Harvey map summit spot height has a 2m or more discrepancy when compared to the survey result produced by the Trimble GeoXH 6000 or analysis of data produced via LIDAR, also included are hills whose summit map data is missing an uppermost ring contour when compared to the data produced by the Trimble or by LIDAR analysis.

Therefore, the new listed summit height of this hill is 408.8m and this was derived from LIDAR analysis, 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 6.8m higher than the previously listed 402m summit height, which appeared as a 1,320.4ft (402.46m) surface height on the Ordnance Survey Six-Inch map published in 1852. 

 

The full details for the hill are:

Group:  Pendle

Name:  Soil Hill

OS 1:50,000 map:  104

Summit Height (New Height):  408.8m (LIDAR)

Summit Grid Reference:  SE 07680 31368 (LIDAR)

Col Height:  348.6m (LIDAR)

Col Grid Reference:  SE 06547 31672 (LIDAR)

Drop:  60.2m (LIDAR)

 

Myrddyn Phillips and Aled Williams (June 2023)