Mapping Mountains – Hill Reclassifications – The Fours - The 400m Hills of England

Dow Low (SK 098 678) – 400m Sub-Four addition

There has been an addition to the listing of The Fours due to analysis of data on the OS Maps website, which is the recent replacement for OS Get-a-map, with confirmation from subsequent LIDAR analysis conducted by Myrddyn Phillips.  The Fours is the title for the list of 400m hills of England and takes in all English hills at or 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 2^nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24^th April 2018.

Accompanying the main list of The Fours are three categories of sub hills, with this hill being added to the 400m Sub-Fours.  The criteria for 400m Sub-Four status are all English hills at or above 400m and below 500m in height that have 20m or more and below 30m of drop.  

Prior to analysis of data on OS Maps this hill was not classified as its present construction is the result of mining activity from the Hindlow Quarry; therefore it does not possess any upper ring contours on the Ordnance Survey 1:50,000 Landranger or 1:25,000 Explorer maps.

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

The land where the summit of this hill is situated is positioned on that associated with Dow Low (SK 093 675) and therefore it is listed by the same name.  The hill is situated in the Southern Pennines and is placed in Region 36, with its Cardinal Hill being Axe Edge (SK 035 706).  The hill is positioned between the B 5053 road which is to its west and the A 515 road to its north-east and has the town of Buxton to its north north-west.

View of Dow Low (SK 098 678)

As the summit of the hill is not a part of designated open access land and a part of a working quarry permission to visit should be sought, for those wishing to do so an ascent from the north-east may prove the easiest.

The initial addition of this hill to 400m Sub-Four status is due to the analysis of data on the OS Maps website coupled with analysis of imagery on Google Maps and Google Earth concluding that the hill is solid and stable.  The mapping on the OS Maps website gives contour intervals at 5m which has enabled the height of the summit and col to be estimated when compared to the lack of detail on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer maps.  Therefore with an estimated summit height of c 416m based on an uppermost 415m ring contour on OS Maps and an estimated col height of c 388m, based on col contouring on OS Maps between 385m – 390m, these values give this hill an estimated c 28m of drop, which is sufficient for it to be classified as a 400m Sub-Four.

Extract from OS Maps

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 image of Dow Low (SK 098 678)

Therefore, the confirmation of the addition of this hill to 400m Sub-Four status is due to LIDAR analysis, resulting in a 419.2m summit height and a 398.0m col height, with these values giving this hill 21.2m of drop, which is sufficient for it to be classified as a 400m Sub-Four.

 

The full details for the hill are:

Cardinal Hill:  Axe Edge

Name:  Dow Low

OS 1:50,000 map:  119

Summit Height:  419.2m (LIDAR)

Summit Grid Reference:  SK 09807 67866 (LIDAR)

Col Height:  398.0m (LIDAR)

Col Grid Reference:  SK 09828 67761 (LIDAR)

Drop:  21.2m (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:

The Fours

The Fours – 400m Sub-Four

The Fours – 390m Sub-Four

The Fours – 390m Double Sub-Four

Myrddyn Phillips and Aled Williams (August 2018)