Fforest (SN 944 900)
There has been a Summit Relocation to a hill that
is listed in the
Y Pedwarau – The 400m Hills of Wales and
the Y Trichant – The 300m Hills of Wales,
with the summit height and its position confirmed
via LIDAR analysis conducted by Aled Williams.
 |
| LIDAR image of Fforest (SN 944 900) |
The criteria for the two listings
this summit relocation affects are:
Y Pedwarau – The 400m Hills of Wales. Welsh hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main Y Pedwarau list are five categories of sub hills, with this summit relocation applying to a hill listed in the 390m Sub-Pedwar category, with the criteria for this sub category being all Welsh hills at or above 390m and below 400m in height that have a minimum 30m of drop. The list is co-authored by Myrddyn Phillips and Aled Williams, with the Introduction to the Mapping Mountains publication of this list appearing on the 30th January 2017, and the list is now available in its entirety on Mapping Mountains in Google Doc format.
Y Trichant
– The 300m Hills of Wales. Welsh hills at or above 300m and below 400m
in height that have 30m minimum drop, with an accompanying sub list entitled the Sub-Trichant with the criteria for this sub category
being all Welsh hills at or above 300m and below 400m in height with 20m or
more and below 30m of drop. The list is authored by Myrddyn Phillips, with the
Introduction to the list and the renaming of it appearing on Mapping Mountains on the 13th May 2017.
The name the hill is listed by is Fforest and it is adjoined
to the Pumlumon group of hills, which are situated in the northern part of Mid and West Wales (Region B,
Sub-Region B2), and
it is encircled by minor roads and has the Afon Trannon to its north and a part
of the B4569 road towards the east, and has the village of Trefeglwys towards
the east north-east.
When the original 300m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website the summit height of this hill was listed as 391m which was based on the spot height positioned at SN 94301 90124 that appears on the Ordnance Survey 1:25,000 Explorer map.
 |
| Extract from the Ordnance Survey 1:25,000 Explorer map |
When the 1st edition of the Y Pedwarau was published by Europeaklist in May 2013 the hill
appeared under the details given above using the six figure grid reference of
SN 943 901. These details were amended
for the Y Pedwarau list appearing on
Mapping Mountains with the ten figure summit grid reference of SN 94294 90127
used, with this being taken from details on DoBIH.
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 bwlch image for Fforest |
The summit height produced by LIDAR analysis is 391.5m
at SN 94401 90011 and its position in relation to that previously given comes within the
parameters of the Summit Relocations used within this page heading, these
parameters are:
The term Summit Relocations applies to any listed
hill whose summit meets the following criteria; where there are a number of
potential summit positions within close proximity and the highest point is not
where previously given, or a relocation of approximately 100 metres or more in
distance from either the position of a map spot height or from where the summit
of the hill was previously thought to exist, or when the summit of the hill is
in a different field compared to where previously given, or when it is
positioned to a different feature such as in a conifer plantation, or when the
high point of the hill is placed within a different map contour compared to its
previous listed position, or when the natural and intact summit of a hill is
confirmed compared to a higher point such as a raised field boundary that is
judged to be a relatively recent man-made construct.
Therefore, the summit
height produced by LIDAR analysis is 391.5m and is positioned at SN 94401 90011,
this position is not given a spot height on contemporary Ordnance Survey maps
and is approximately 120 metres south-eastward from where the previously listed
summit is positioned.
The full details for the hill are:
Group: Pumlumon
Name: Fforest
OS 1:50,000 map: 136
Summit Height: 391.5m (LIDAR)
Summit Grid Reference (New Position): SN 94401 90011 (LIDAR)
Bwlch Height: 355.8m (LIDAR)
Bwlch Grid Reference:
SN 93945 89099 (LIDAR)
Drop: 35.7m (LIDAR)
Myrddyn Phillips and Aled Williams (November 2019)
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