Introduction
Y
Pedwarau – The 400m Hills of Wales
Publication
History
Y
Pedwarau are the Welsh hills at or above 400m and below 500m in
height that have a minimum drop of 30m.
The list’s initial compilation was completed in November 2002 and
entitled The 400m Peaks of Wales and
was first published on 19th December 2002 on the RHB Yahoo Group
file database along with the equivalent English and Manx hills, with the file
entitled the 400m hills of England, Isle
of Man and Wales, this file was uploaded by Rob Woodall who later augmented
data from Clem Clements into the database.
The listing was re-evaluated and later published on 22nd
October 2004 on Geoff Crowder’s v-g.me website and entitled The Welsh 400 Metre Peaks, coinciding
with Geoff’s publication the list was also published by Mike Grant on his
5everdene website.
The master hand written list was maintained by Myrddyn
Phillips with occasional updates appearing on the v-g.me website, with the
original publication on the RHB Yahoo Group file database later being
duplicated en masse by Mark Jackson without prior consultation with, or even
notification to the author, with these data forming the equivalent part of the
Tumps and with this act resulting in years of undue data divergence that is
ongoing.
The list was next fully re-evaluated for publication by
Europeaklist on 23rd May 2013, with the compilation now entitled Y Pedwarau and leading the way to the
list becoming co-authored with Aled Williams.
The listing of Y Pedwarau was
later published on 6th January 2014 by Phil Newby on his
Haroldstreet website, and all future updates to the list have been catalogued
on the Mapping Mountains site.
Y
Pedwarau on
Mapping Mountains
Since Y Pedwarau
was published by Haroldstreet there has been a number of reclassifications to
the list, all of these have been reported on Mapping Mountains, but few have
found their way into the Haroldstreet publication.
With the advent of independent surveyors and the accuracy of
LIDAR data it is becoming increasingly more difficult to keep a list up-to-date
if it is hosted on another person’s website, and for these reasons it has
become evident that Mapping Mountains should host the master Y Pedwarau list.
Y
Pedwarau will be published on Mapping Mountains in hill group format
on an ad hoc basis. Therefore when each
hill group has been compiled with all relevant detail it will be uploaded to
the Master List which will be available in Google Doc format on the Mapping
Mountains site. As the list will be
published by group format and therefore not initially in its entirety, it will
take approximately a year until the complete up-to-date list is available on
the Mapping Mountains site.
As well as the main Y
Pedwarau list being published the Mapping Mountains publication will also
have five Sub lists accompanying the main P30 list, these Sub lists are:
500m
Sub-Pedwarau - Welsh hills at or above 500m and below 510m
in height with 30m minimum drop.
500m
Double Sub-Pedwarau - Welsh hills at or above 500m and below 510m
in height with 20m or more and below 30m of drop.
400m
Sub-Pedwarau - Welsh hills at or above 400m and below 500m
in height with 20m or more and below 30m of drop.
390m
Sub-Pedwarau - Welsh hills at or above 390m and below 400m
in height with 30m minimum drop.
390m
Double Sub-Pedwarau - Welsh hills at or above 390m and below 400m
in height with 20m or more and below 30m of drop.
To the knowledge of the authors this is the first time that
a higher tier Sub category has accompanied a list that includes the standard
lower tier Sub category. In this
instance the higher tier is the 500m
Sub-Pedwarau and 500m Double
Sub-Pedwarau and the lower tier is the 390m
Sub-Pedwarau and the 390m Double
Sub-Pedwarau. One without the other
is being inconsistent, that is now rectified for Y Pedwarau.
The list consists of the following:
Group: Each hill appears under their Group, this is
the group / range that the hill is a part of.
For example; Crimpiau (SH 733 595) is a part of the hill group known as
the Carneddau. The Groups are arranged
from north to south on a west to east orientation.
Name: This is considered the most appropriate name
for the hill with respect to the information available to the authors. Sometimes the name used does not correspond
to current Ordnance Survey map spelling and composition or the name may not
appear on any map. Where no appropriate
name has been discovered for the hill from any source, the Point (for example;
Pt. 478m) notation is used rather than making up a name that has no local or
historical evidence of use.
Summit
Height (m): This
gives the map height in metres of the hill above Ordnance Datum Newlyn (ODN),
often referred to as sea level. Where a
height is quoted to a decimal place it implies that the hill has been surveyed
by GPS / GNSS receiver or obtained from LIDAR analysis (these heights
may not match current Ordnance Survey map heights), with the heights produced by GNSS receiver converted to OSGM15. Where a ‘c’ (circa) appears preceding the
height it means there is no known spot height available and the height has been
estimated from contour interpolation.
Region: There are three Regions in
Wales; North Wales, Mid and West Wales, and South Wales. The Regional split of Wales used in this list
has been documented on the Mapping Mountains site.
Sub-Region: The three Regions of Wales are
further split up into Sub-Regions, this sub-division takes in the topography
and geography of each Region.
1:50,000
Map: This column gives the number or numbers of
the 1:50,000 Ordnance Survey Landranger map that the summit of the hill appears
on.
1:25,000
Map: This column gives the number or numbers of
the 1:25,000 Ordnance Survey Explorer map that the summit of the hill appears
on.
Cardinal
Hill: Each hill group can
be split into Cardinal Hills; these are the hills of most significant height or
drop/prominence. In affect these are the
‘Grouped Parent Hills’ to any individual hill that is listed. Since publication of Y Pedwarau by Europeaklist in May 2013 the Cardinal Hills for Wales
have been fully re-evaluated and updated accordingly.
Summit Grid
Reference: This is the ten
figure grid reference (10FGR) for the summit of the hill. This has either been produced by an accurate
survey, a map spot height or when neither is available by a centralised position
in an uppermost contour ring.
Summit Grid Reference extracted from: Details of where the ten figure grid reference for the summit was derived.
Drop (m): This column details the prominence of the hill; this is commonly referred to as ‘drop’ or ‘reascent’. The drop is the height difference between the summit and connecting bwlch to the higher parent peak along the watershed. The letter ‘c’ before the drop figure signifies there is no spot height or surveyed height known for either summit or more usually, the bwlch, therefore a part of the drop figure has been estimated from contour interpolation.
Summit Grid Reference extracted from: Details of where the ten figure grid reference for the summit was derived.
Drop (m): This column details the prominence of the hill; this is commonly referred to as ‘drop’ or ‘reascent’. The drop is the height difference between the summit and connecting bwlch to the higher parent peak along the watershed. The letter ‘c’ before the drop figure signifies there is no spot height or surveyed height known for either summit or more usually, the bwlch, therefore a part of the drop figure has been estimated from contour interpolation.
Notes: This column gives details relating to the
hill.
Thanks are given to the people who submit 10 figure grid
references to the Database of British and Irish Hills (DoBIH) and for DoBIH
making these available for public use.
To
access the Y Pedwarau Change Registers:
Myrddyn Phillips and
Aled Williams (January 2017)
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