So some data I used from the 2011 UK census (England, Wales and Cornwall) was 1. those with a skill in the Welsh language (the full question was only asked of census respondents living in Wales) and 2. those self-describing as Cornish for national identity.
The data is converted from census output polygons, to dots randomly placed within the part of the output polygon below 300m altitude.
Although there is quite a lot of land above 300m in Wales, there is actually only one or two census output area polygons that entirely disappear when terrain above 300m is cut out. So if you're in Blaenavon, apologies for deleting you.
Using the environmental layers of elevation, slope (from Shuttle Radar Topography Mission) and distance from the coast, this is the output:
|Notice that the habitat suitability for Welsh speakers is actually higher in areas such as the North York Moors, and North Devon than Ynys Môn.|
|Habitat suitability drops off further than 60km from the coast|
|Altitudes of 200m-300m appear to be most suitable for Welsh speakers according to the observations of the census data.|
|The Welsh speakers are not suited to living on flat terrain.|
|A range of coastal areas are suitable for resettlement of the Cornish in the event of for example, unexpected reactivation of the igneous activity of the Cornubian batholith.|