Dinas Fach (SM 825 226) – 30-99m Twmpau addition
There has been an addition to the list of 30-99m Twmpau, with the summit height, bwlch height and their locations, the drop and status of the hill obtained from the summit analysis programme that uses LIDAR produced by Joe Nuttall, and then by LIDAR analysis initially conducted by Jim Bloomer and subsequently by Myrddyn Phillips.
LIDAR image of Dinas Fach (SM 825 226) |
30-99m Twmpau – Welsh hills at or above 30m and below 100m in height that have 30m minimum drop, with an accompanying sub list entitled the 30-99m Sub-Twmpau with the criteria for this sub category being all Welsh hills at or above 30m and below 100m in height with 20m or more and below 30m of drop, with the word Twmpau being an acronym standing for thirty welsh metre prominences and upward.
The 30-99m Twmpau by Myrddyn Phillips |
When the original 30-99m height band of Welsh P30 hills were published on Geoff Crowder’s v-g.me website this hill was not included in the main P30 list or the accompanying Hills to be surveyed sub list, as it was considered not to meet the criteria then used in either category.
Extract from the Ordnance Survey 1:50,000 Landranger map |
Extract from the Ordnance Survey 1:25,000 Explorer map |
Extract from the Magic Maps website |
Therefore, the addition of this hill to 30-99m Twmpau status is due to LIDAR analysis, resulting in a 30.45m summit height and a 0.3m bwlch height, with these values giving this hill 30.15m of drop, which is sufficient for it to be classified as a 30-99m Twmpau.
The full details for the hill are:
Group: Carn Llidi
Name: Dinas Fach
OS 1:50,000 map: 157
Summit Height: 30.45m (LIDAR)
Summit Grid Reference: SM 82559 22659 (LIDAR)
Bwlch Height: 0.3m (LIDAR)
Bwlch Grid Reference: SM 82605 22745 (LIDAR)
Drop: 30.15m (LIDAR)
Myrddyn Phillips
(September 2021)
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