## 2 Materials and Methods
### Archaeological Sites  
This research also relies on the knowledge of site locations; however, accurate coordinates for archaeological sites are not always available. This is especially true for settlements investigated by older salvage projects which, due to time constraints, rarely revisit a site after the first discovery, especially if it was not a target for rescue excavation. Moreover, technological limitations impact the quality of information about a site location [56] (pp. 47-50). In order to work properly in a GIS environment, data on archaeological sites from the study regions were gathered from two primary sources:  
* An open, and freely available dataset of Google Earth placemarks, available as a.kmz file named \"ANE.kmz\", which stores name and location of more than 2500 archaeological sites across Egypt and the Near East [54];
* Manual georeferencing of archaeological site distribution maps published in scientific reports. For the Haditha Dam [10] (Figure 4); for the Mosul Dam [57] (map 3), [58] (map 2), [59] (map 2); for the Hamrin Dam [54] (map 2). The addition of the second source of data was necessary because the ANE.kmz, although massive, does not store a complete inventory of all the archaeological sites in the study areas. In order to digitise sites from the distribution maps with enough accuracy, it was necessary to operate in a series of steps, which are part of a common procedure for repositioning sites in GIS, especially for Near Eastern archaeologists, who often deal with old survey data. These steps, apart from georeferencing the maps, combine the analysis  
Figure 6: Study area—the Hamrin Dam region. of site location descriptions and topographic maps provided by scientific reports and the use of satellite imagery, in order to improve the accuracy of repositioning a site in GIS (see ref [56] pp. 50-53 for an overview of the process). However, it was not always possible to relocate all known sites in each area with enough confidence, and the resulting dataset used in this research is necessarily incomplete. The final dataset consisted of 54 sites for the Haditha Dam, 48 for the Mosul Dam, and 42 for the Hamrin Dam, for a total of 144 archaeological sites (see also Section 2.4.2). The dataset used here for the Mosul Dam is different from the one published in Sconzo; Simi, 2020 [60]. While location precision for sites analysed in this paper was checked against that dataset, the overall accuracy and related results might have changed. The Mosul Dam dataset published in Sconzo; Simi, 2020 [60] will be the target of a future, more accurate, endeavour conducted by [PERSON], [PERSON], and [PERSON] using the same methodology applied here. This research also relies on the possibility of measuring the resurfaced extent of an archaeological site. For this reason, polygons representing the extent of a site were drawn in GIS, based on their visibility on satellite images coupled with topographic maps, when available. It was not possible to reconstruct the actual extent of all the sites available; therefore, polygons were drawn only for those sites that satisfied the following conditions:  
* On satellite images, the site shows evident features such as walls that delimit its extension;
* Visible topographic features (e.g., a Tell) that was taken as minimum site extent. Such conditions were necessary in order to account for an ongoing discussion about the reliability of overall sites dimensions reconstruction and definition of clear limits for archaeological settlements. This discussion is also tied to the matter of how Near Eastern archaeological surveys have historically been conducted (see, e.g., [PERSON], 2002 [61], pp. 81-84; [PERSON], 2012 [56], pp. 54-56). All these elements dictate careful consideration when dealing with sites' extent. For this reason, simple dimensions such as, e.g., \"50 \(\times\) 100 m\" provided by survey reports were not considered here, and only sites that met the conditions highlighted before were included in the analysis.