Thursday, 7 June 2018

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


Shovel Down (SX 658 857) – 400m Sub-Four deletion

There has been a deletion to the listing of 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 initially conducted by Aled Williams and subsequently by Myrddyn Phillips.

LIDAR image of Shovel Down (SX 658 857)

The criteria for the list that this deletion applies to 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, with this hill being deleted from 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 name the hill is listed by is Shovel Down and it is adjoined to the High Willhays group of hills, which are situated in Dartmoor in the south-west of England, and it is positioned with minor roads to its north-east and south-east and the B3212 road farther to its south-east and the A382 road farther to its north-east, and has the town of Chagford to the east north-east.

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 an estimated c 21m of drop, based on a 435m summit height and an estimated c 414m col height, with the latter based on interpolation of 10m contouring between 410m - 420m.  

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

The 435m summit height was taken from what was presumed to be a 1,427ft (434.954m) height that appeared on the Ordnance Survey 1:10,560 map.  However, the last figure of the imperial height was blurred and a ? was added to the hand written notes accompanying the listing of this hill.  The Ordnance Survey 1:10,000 series of maps has this figure as 1,421ft (433.126m).

Extract from the Ordnance Survey 1:10,000 series of 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.

Therefore, the deletion of this hill from 400m Sub-Four status is due to LIDAR analysis, resulting in a 432.8m summit height and a 413.4m col height, with these values giving this hill 19.3m of drop, which is insufficient for it to retain its 400m Sub-Four status. 


The full details for the hill are:

Group:  High Willhays

Name:  Shovel Down

OS 1:50,000 map:  191

Summit Height:  432.8m (LIDAR)

Summit Grid Reference:  SX 65837 85738 (LIDAR)

Col Height:  413.4m (LIDAR)

Col Grid Reference:  SX 66235 86023 (LIDAR)

Drop:  19.3m (LIDAR)


For the additions, deletions and reclassifications to The Fours - The 400m Hills of England reported on Mapping Mountains since the December 2013 publication of the 1st edition of this list by Europeaklist please consult the following Change Registers:










Myrddyn Phillips and Aled Williams (June 2018)

No comments:

Post a Comment