Mitigating the impacts of environmental change on cultural heritage using drone-based survey techniques

With the increasing effects of climate change, archaeological sites in coastal regions are increasingly under threat by coastal or fluvial erosion, melting permafrost or rising sea levels (Masselink and Russell 2013). Due in part to a lack of resources and remoteness of some locations, many sites are unstudied and lack adequate environmental management strategies despite being vulnerable to destruction, often resulting in a significant loss of knowledge of human history. The recent SCHARP project (www.scharp.co.uk), for example, surveyed approximately 35% of the Scottish Coast, assessing 12000 recorded monuments (See also Rennie et al 2017). The results indicated that 4000 of these sites needed some form of archaeological intervention, with even the c.100 sites marked as a priority proving a number far exceeding the physical and economic capacity of any state or commercial body. In many instances, unless major infrastructure is threatened, the state takes a minimal approach to coastal management, allowing the coastline to evolve naturally over time, primarily due to the expense of engineering solutions and the adverse ecological effects they can have. However, unlike certain environments or ecosystems that can migrate naturally or by engineered intervention, archaeological monuments cannot be re-created elsewhere - they are a diminishing resource.

Many threatened coastal sites have not been subject to detailed recording, either by conventional ground-based methods or modern techniques such as airborne LiDAR. Both methods can be costly and time consuming, and require skilled individuals to undertake and/or process the collected data. The recent application of drone technology is quickly revolutionising many sectors, including archaeology. Drone derived photogrammetry, in particular, has become an important and cost effective technique for recording cultural heritage (e.g. O'Driscoll 2018). Its effectiveness in wider landscape studies, however, has not yet been fully realised, despite the technique allowing users to undertake large-scale topographical survey and create dense three-dimensional models at a fraction of the cost of LiDAR, and at a much higher spatial resolution. High-resolution topographical surveys can contribute greatly to the recording of extant archaeological sites as well as the identification of previously unseen surface features.

While there are clear applications for such technology in a heritage management capacity, other novel drone-based techniques can add further value. The potential for thermal, multi- and hyper-spectral imaging to detect subsurface archaeology is well known. Until recently these techniques were confined to low-resolution satellite and light-aircraft derived surveys which are costly and are often undertaken in conditions unfavourable for archaeology. However, with the advent of modern drones and a significant evolution in hardware, these techniques have become more applicable to archaeologists, though there are little published examples of their use.
In this regard, the project will assess the ability of developing drone technology and other relatively low-cost remote sensing techniques to rapidly record and discover archaeological sites threatened by coastal erosion. The candidate will be trained in the use and applicability of a variety of interdisciplinary and novel methods of survey, with the results of the project having the potential to feed into policy making and heritage management, while also being used as a resource allocation tool for government agencies.