Grongaer (SN 573 215) – Subhump deletion
This is the fourth in a series of Hill Reclassification posts
that detail hills whose status has been altered in the listing of the Humps (HUndred Metre Prominences)
through map study and / or surveys that I have conducted.
The hill name used in this and forthcoming posts is that used
in the listing of Humps, therefore
individual names and their composition may not match those that are used in listings I am directly
associated with. However, I am of firm
belief that listed hill names used by other authors should be respected when
giving detail within other people’s lists, however inappropriate some hill
names may be considered.
This and forthcoming posts are retrospective as many of these
hill reclassifications were initiated from studying the Ordnance Survey
enlarged mapping that is hosted on the Geograph website, and for the
reclassifications that affected the Humps
the email I posted on the RHB Yahoo Group forum in relation to this hill was
dated 15.04.12.
The listing of Humps
was published in book format by Lulu in 2009 and entitled More Relative Hills of Britain, its author; Mark Jackson gives
credit to a number of people who contributed toward the formation of this list,
these include; Eric Yeaman, Alan Dawson, Clem Clements, Rob Woodall, Bernie
Hughes, Pete Ridges and others. When the
list was published in book format there were 2987 Humps listed with their criteria being any British hill that has
100m or more of drop, accompanying the main list is a sub category entitled the
Subhumps, with the criteria being any
British hill that has 90m or more and below 100m of drop.
 |
| More Relative Hills of Britain by Mark Jackson |
The details for the reclassification appear below:
There has been a deletion to the listing of the Humps (HUndred Metre Prominences) due to
consulting the Ordnance Survey enlarged mapping that is hosted on the Geograph
website, with these details being posted on the RHB Yahoo Group forum on 15.04.12.
Prior to this notification Mark Jackson had listed this hill
as a Subhump with c 91m of drop based
on the 143m summit spot height on the Ordnance Survey 1:25,000 Explorer map and
an estimated bwlch height of c 52m based on bwlch contouring at 10m intervals, interpolation
of bwlch contouring was helped by the use of 5m contour intervals on the
Ordnance Survey enlarged mapping hosted on the Geograph website and therefore
the estimated bwlch height could be better refined to c 54m, and when coupled
with this hill’s 143m summit spot height these values give this hill c 89m of
drop, which is insufficient for it to retain its Subhump status.
 |
| Extract from the Ordnance Survey enlarged mapping hosted on the Geograph website showing the 5m contour lines at the bwlch of this hill |
The hill name appears as Grongaer in the listing of Humps which is its current composition on the Ordnance Survey 1:25,000 Explorer
map. However, its composition on the
current Ordnance Survey 1:50,000 Landranger map is Gron-gaer and it has also
been recorded by the Ordnance Survey as Grongar Hill (Six-Inch map and Historical
1:25,000 map). Whilst preceding the name
of the hill with the use of the definite article Y (Y Grongaer) is recommended
in A Gazetteer of Welsh Place-Names
(University of Wales Press 1967).
The hill is adjoined to the Mynydd Mallaen range of hills and
is situated overlooking the Afon Tywi (River Towy) which is to its south-east,
and the A 40 road which is to its north, with the town of Llandeilo positioned
towards the east of the hill.
The deletion of this hill from Subhump status was accepted by Mark Jackson on the 21.07.12 and the
listing of the Humps was updated
accordingly.
The full details for the hill are:
Name: Grongaer (as
listed in the Humps)
Summit Height: 143m
OS 1:50,000 map: 159
OS 1:25,000 map: 186
Summit Grid Reference:
SN 57315 21592
Drop: c 89m
Myrddyn Phillips (August 2017)
No comments:
Post a Comment