I have been looking at these again, and have produced a few maps with the QOSM plugin, which dynamically loads OpenStreetMap tiles into QGIS.
These maps below were produced with the Thunderforest Outdoors rendering. The slopelines are as previously, red for convex slopes, blue for concave, with thicker lines denoting steeper slopes.
Previous versions of this had used a version of OpenStreetMap that I was preparing myself from the source data within QGIS. Using the basemap tiles I can focus on adapting the visualisation of the slope lines themselves a bit more.
|Camborne and Redruth, including Carn Brea and Portreath|
|A close up of Truro|
|Indicating the downslope direction with arrows.|
|Delabole, showing the slate quarry.|
|Cadair Idris, Wales|
|A wider view of Cadair Idris, too small a scale to allow plotting the arrows.|
|Pen y Fan, Brecon Beacons, Wales|