# Detecting Change at Archaeological Sites in North Africa Using Open-Source Satellite Imagery
## 1 Introduction
The EAMENA project has already demonstrated the potential  
Figure 1: Location of study areas in Libya and Egypt. of this for our huge study region [1; 20]. Most studies, whether using high- or medium-resolution imagery, are confined to drawing attention to problems at single, well-known sites and offer no solution for how remote sensing and automated approaches could protect sites. [PERSON] et al. [13] apply partially supervised classification algorithms to detecting change using high-resolution imagery of the pyramids in Egypt and propose that this could be valuable to archaeologists, but do not offer any concrete solutions for its widespread use in the country. EAMENA's unique database of over 170,000 sites and network of trained heritage professionals offers an unprecedented opportunity to address this challenge. In this paper, we apply our methodology to a case study in Egypt with the AKAP project. EAMENA team members [PERSON] and [PERSON] collaborated with AKAP on two field seasons (in November 2018 and January 2020), particularly focusing on recording the condition of sites and validating the initial results of change detection using remote sensing. Since 2005 AKAP has worked in selected areas north of the modern city of Aswan, both along the Nile and in the desert hinterland, recording a variety of sites dating from the Palaeolithic to the pre-modern era, and consisting of isolated finds, scatters, towns, temples, cemeteries, quarries, and rock art. The area corresponds to the region of the First Nile Cataract, an important crossroads in Northeastern Africa that for long periods marked the border between ancient Egypt and Nubia. Archaeological sites in the region are threatened by land reclamation, quarrying, and urban development, including the construction of a new city (New Aswan) on the west bank north of Aswan. Our second case study for this paper is the Jufra area of Libya. EAMENA and Dr [PERSON] collaborated with the Trans-SAHARA project on the Jufra case study. The Trans-SAHARA project has recorded sites across a vast area of Saharan Africa and its periphery [21]. In 2013 [PERSON] undertook field survey to collect dating material, and [PERSON] and [PERSON] subsequently digitised the archaeological sites using satellite imagery. [PERSON] and [PERSON] have most recently worked on change detection applied to these sites. Jufra consists of three Saharan oases in central Libya: Sukna, Hun, and Waddan. Each has an urban centre and a large area of irrigated oasis gardens of cereals and cultivated palms. Jufra has some of the earliest evidence for agriculture in the Central Sahara with two areas of foggaras (subterranean ground-water transporting channels) and associated settlements to the south of Hun and Waddan [15] (130-137). These probably date to the early first millennium AD (if not earlier). Slightly later in date are four nucleated settlements of densely packed rectilinear structures that sit within large and extensive field systems. Radiocarbon dating of material from the walls of these settlements suggest they date to the early medieval period and the expansion of trans-Saharan trade (seventh to ninth centuries AD) [15], but Roman pottery observed during a field survey in 2013 from at least one of these suggests an earlier origin. To the north of Hun is a late medieval walled town with a mosque and an attached cemetery. Finally, the most recent sites are the former towns of Sukna, Hun, and Waddan. The agricultural areas of this last phase are still detectable in modern land divisions and remained largely the same up until the 1970s.