A new map of Doone Hill & Fairy Knowe for CLYDE: old map hits new technology

When the Covid lock-down hit, I started looking for illicit maps on the dark interwebs to run on... One of the first and best I found was CLYDE's map for Fairy Knowe and Doone Hill near Aberfoyle. This is a fantastic area of many medium-sized rugged hills covered with mature oak forest and mature plantation interspersed with streams and marshes. On many runs I would run into deer and otters, and see eagles fly overhead.

I recently acquired suitable LiDAR data, which is now being used for a new fully georeferenced map expanding into new areas. I had not realised what a daunting task it would be! The issue is that this map is pretty old: first mapped (as far as I can tell) by CLYDE's Donald Petrie & father in 1987, it was changed/expanded by Marcus Pinker in 2012, Jon Musgrave in 2016, and Alasdair Pedley in 2022, and possibly had contributions from others as well. In 1987, there was no Google maps, no LiDAR data, no cheap GNSS... So, this map (like nearly all old maps) was topologically correct but geographically a hodgepodge: that is, features were all there and had the more or less correct relationship to each other but were in the wrong geographical place.

My approach (not necessarily the best one) was to convert the old map into a jpeg and rubber-sheet it to the new contours generated from the DSM. Then followed by the long and laborious process of putting all the features (streams, cliffs, boulders, etc.) back in places that seemed most logical from a landscape point a view (cliffs are on downhill slopes, etc. once you placed them, the location of other point features is with respect to these cliffs, etc.). This was then followed by in-person recces with the GNSS set-up to put all these features in exactly the right place and make (many!) corrections and additions.

The task for late 2023 and 2024 is to completely update the vegetation. LiDAR data were analysed using the normalised difference vegetation density (NDVD) statistical analysis technique to get a surprisingly accurate basemap. This is now being converted into a useable and accurate orienteeriong map. Below is a map extract around Kirkton Hill. Hopefully you will find the whole map at an orienteering event reasonably soon.

Extract from the new CLYDE Doon Hill and Fairy Knowe orienteering map