Wapley Hill (SO 347 624)
There has been a Significant Height Revision to a
hill that is listed in the Tumps. This height revision was initiated by a
survey with the Trimble GeoXH 6000 which took place on the 15th
February 2018 in good conditions with clear visibility, albeit quite chilly.
The name of the hill is Wapley Hill and it is
situated in Region 38 the Welsh Borders and in Section 38B West
Gloucestershire, Hereford and Worcester. The hill is positioned above the B 4362
road which is to its north, and has the town of Llanandras (Presteigne) towards
its north-west and the village of Shobdon towards its east.
 |
| Wapley Hill (SO 347 624) |
All of the upper part of the hill except for its
northern section is a part of designated open access land, and although much of
this upper section is forested there are a series of way-marked footpaths
leading to its summit, which comprises an impressive Iron Age hill fort.
Prior to the survey with the Trimble GeoXH 6000
this hill was listed with a 329m summit height based on the spot height that
appears on the Ordnance Survey 1:25,000 Explorer map. The high point of the hill positioned on one
of the ancient embankments that form a series of five defences, this embankment
has a modern constructed entrance carved through it, and either side of this,
to its immediate north, and its immediate south, are high points, each vying
for the accolade of this hill’s summit position, with the northern one having
been Abney levelled by numerous people as being slightly higher.
 |
| Extract from the Ordnance Survey 1:25,000 Explorer map |
 |
| Extract from the Ordnance Survey Interactive Coverage map hosted on the Geograph website |
These two high points were surveyed with the
Trimble GeoXH 6000, the results are:
Northerly high point: 332.668m (converted to OSGM15) at SO 34754
62456
Southerly high point: 332.774m (converted to OSGM15) at SO 34749
62440
 |
| The Trimble GeoXH 6000 gathering data at the northerly high point of Wapley Hill |
 |
| The Trimble GeoXH 6000 gathering data at the southerly high point of Wapley Hill |
The 332.8m (converted to OSGM15) summit height
produced by the Trimble GeoXH 6000 is 3.8m higher than the previously listed
height of 329m, which was based on the Ordnance Survey spot height that appears
on the 1:25,000 Explorer map and which is positioned on the downward slope of
the summit embankment, and therefore this new height 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 hill whose 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.
As heights on different scaled Ordnance Survey maps are not consistent
the height given on the 1:25,000 Explorer map is being prioritised in favour of
the 1:50,000 Landranger map for detailing these revisions.
The southerly summit of this hill is easily
identified and consists of grass on the path that follows the higher of the
embankments that form this ancient hill fort, it has steep ground either side
of it, whilst the northerly summit is positioned near the base of a small oak
tree and which is beside the narrow path that follows the continuation of the
same higher embankment.
Therefore this hill’s new summit height is 332.8m
(converted to OSGM15), which is 3.8m higher than its previously listed height
which came from the 329m spot height on contemporary Ordnance Survey 1:25,000
Explorer maps.
The full details for the hill are:
Group: Fforest Glud
Summit Height (New Height):
332.8m (converted to OSGM15)
Name: Wapley Hill
OS 1:50,000 map: 137,
148, 149
Summit Grid Reference:
SO 34749 62440
Drop: 160.2m (Trimble summit and LIDAR col)
Myrddyn Phillips (March 2018)
No comments:
Post a Comment