Detecting Change at Archaeological Sites in North Africa Using Open-Source Satellite Imagery

Abstract

Our paper presents a remote sensing workflow for identifying modern activities that threaten archaeological sites, developed as part of the work of the Endangered Archaeology of the Middle East and North Africa (EAMENA) project. We use open-source Sentinel-2 satellite imagery and the free tool Google Earth Engine to run a per-pixel change detection to make the methods and data as accessible as possible for heritage professionals. We apply this and perform validation at two case studies, the Aswan and Kom-Ombo area in Egypt, and the Jufra oases in Libya, with an overall accuracy of the results ranging from 85–91%. Human activities, such as construction, agriculture, rubbish dumping and natural processes were successfully detected at archaeological sites by the algorithm, allowing these sites to be prioritised for recording. A few instances of change too small to be detected by Sentinel-2 were missed, and false positives were caused by registration errors, shadow and movements of sand. This paper shows that the expansion of agricultural and urban areas particularly threatens the survival of archaeological sites, but our extensive online database of archaeological sites and programme of training courses places us in a unique position to make our methods widely available.

Ethical considerations for remote sensing and open data in relation to the endangered archaeology in the Middle East and North Africa project

“…Banks et al, 2017). Alongside this, we are experimenting with automatic site and change detection methods; for instance, applying custom algorithms to Google Earth Engine (Rayne et al, 2020). The accumulated information is captured in the EAMENA database, which is a custom instance of the open-source Arches platform (http://archesproject.…”

Monumental funerary landscapes of Dhar Tagant (south‐eastern Mauritania): Towards ethical satellite remote sensing in the West African Sahel

“…Endangered heritage monitoring: The multi-institutional EAMENA team has demonstrated the usefulness of integrating image interpretation, land-use mapping and traditional field survey to record, assess and analyse the preservation status of funerary landscapes in the Homs region of western Syria (Rayne et al, 2017, p. 20). The consensual and collaborative documentation of landscape modification through photogrammetry and satellite imagery archives of archaeological sites at risk of destruction by climate change or anthropogenic processes can lead to more active and effective institutional and external monitoring (Brooks et al, 2020;Campana, 2017;Khalaf & Insoll, 2019;Parcak et al, 2016;Rayne et al, 2020). These phenomena are likely to intensify in the face of increasing regional aridification, which also severely threatens the food security of agropastoral communities throughout the Sahel and beyond.…”

Creating the funerary landscape of Eastern Sudan

“…On the contrary, regions far from the Nile Valley remained, until recently, relatively unexplored due to generally lesser academic interest and lack of infrastructure [10,16]. Nonetheless, they are prone to destruction caused by conflicts and land mismanagement like many other more famed North-African sites [17][18][19].…”