Droning on about Tarradale

by Andy Hickie

Drone image of Tarradale Through Time barrow cemetery dig, as featured in “Current Archaeology” November 2019.

Back in 2017, I caved in to the demands of consumerism, and purchased a new quadcopter, a Phantom 3 Advanced, which is equipped with a camera and GPS unit. I flew multiple flights around Avoch but, after a while, the novelty of seeing one’s house from the air at different angles and altitudes begins to wear thin, and I began to wonder what I could actually do with a drone. Having always had an interest in archaeology and, spurred on by seeing some of the images Alan Thompson of NOSAS had created, I decided to carry out a few experiments of my own.

My first flights took in locations such as the distillery and settlement at Mulchaich, and the features of Kinbeachie castle – sites which had already been mapped by Alan by drone, the results of which I could use as a ‘benchmark’ against which I could compare those of my own.

At the same time, I began experimenting with various flight planning apps which allow for off-line autonomous flight planning, as well as online platforms for image processing. I found that “DroneDeploy” and “Mapsmadeasy” combined provided a fairly user-friendly pipeline, whereby image capture and photogrammetry can produce georeferenced photomosaics and digital surface models (DSMs). These can then be imported into software such as QGIS for further processing.

Having found the software which satisfied my needs, I then turned my attention to potential sites which I could map – and decided on the cropmarks of the Barrow Cemetery at Tarradale. At this point, my intent was purely to satisfy my own curiosity – just to see what I could see, and how it would compare with the archaeology found at the forthcoming 2019 dig.

And so, on 10 June 2018, accompanied by my daughter Emma to act as co-pilot and “spotter”, I visisted Tarradale to map the area with the drone. I can still recall the excitement I felt as the images began to appear on the monitor of the remote controller, which showed the cropmarks were developing. However, my satisfaction was tempered somewhat when I got home and began to process the photographs. Although the cropmarks were indeed evolving, the crop was insufficiently ripe, and many of the details remained hidden (see image below).

A Walkover Survey of Aigas Community Forest

by Roland Spencer-Jones (NOSAS)

In April 2015, NOSAS was approached by the development officer of Aigas Community Forest to see if we could undertake an survey of this newly acquired 285-hectare forest. The local community had completed the purchase of the forest from the Forestry Commission that month. Part of the sale conditions were that an archaeological survey would be required. After some discussion, mainly centred on the size of the task ahead, NOSAS said yes, and the two co-leaders of the survey – Roland Spencer-Jones (RSJ) and Anne Coombs (AC) – got into planning mode.

RSJ undertook a desk-based assessment of the history and known archaeology of the forest. This included searching the maps on the digital map resource of National Library of Scotland, the Canmore archive of Historic Environment Scotland, the local Highland Council’s Historic Environment Record and maps from the previous Lovat Estate archive. In addition he had conversations with local landowners and local community members who had either had personal experience of the forest and its history or had undertaken some research of their own. Two of these local landowners were able to provide old photographs that complemented the historical record.

This desk-based assessment concluded that:

• There was little forest cover in the area now covered by the forest in the mid-18^th century when historical records first began. Much of land was covered in moor and moss, and was “good hill pasture” for grazing animals.
• Planting of the forest began in the mid-19^th century at a time when part of the Aigas Estate was enclosed to both contain stock and to prevent grazing damage. This work was first developed by rich landowners from further south in the UK, as was happening with many other parts of Scotland at that time. A network of paths through the forest was started at this time.

These three photographs demonstrate clearly the successive cropping of the Aigas Forest. The building is Aigas Mains farmhouse, on the southern border of the forest. The photographs are taken in 1933 (above left), 1960 (above right) and 1992 (right)

 

• From 1877 until the early 20^th century the estate was further developed as a sporting estate, with further afforestation and further enclosure of the land. At this time many of the settlements bordering the forest were cleared, and consolidated in houses built in the Crask of Aigas village at the heart of the forest. The path network was expanded, and a road was constructed through the forest to reach the moor above it.
• The forest was progressively consolidated during the 20^th century with successive cycles of planting and cropping. A significant harvest of the trees in the forest occurred in the early 1950’s, which means that it survived the felling that occurred in other Scottish forests during the two World Wars.
• The current forest cover represents a major planting of mixed conifer trees in the early 1960’s.