The Trodden Path: GIS-analyses of Settlement and Mobility Patterns in Western Sicily during the Islamic Period

This study uses GIS spatial analyses to provide explanations for the settlement and mobility patterns of the peasant communities that inhabited the Trapani Mountains during the Islamic period (9th-11th century). The object of analysis consists of 24 medieval settlements, which were identified between 2009 and 2012 as part of the Idrisi Project in the Trapani Mountains. The techniques used in this study are a combination of cost surface analyses (CSA) and line-of-sight analyses (LOSA). Both techniques have demonstrated their potential in providing social and cultural explanations to landscape organization and settlement patterns over the last two decades. The fact that they have never been applied to the chronological and spatial framework of Islamic Sicily represents a considerable advantage for this purpose, as it allows using well-developed techniques in a virgin research context. The paper is divided into four parts. The first one introduces the case study. It gives a brief overview of Islamic archaeology in Sicily and on the research activities of the Idrisi Project, describes the theoretical approach to the study of landscape and ends with the identification of the historical questions analyzed through the application of GIS. The next section tackles the methodology and is divided into two parts, each one dedicated to one group of analyses, CSA and LOSA respectively. The third section is dedicated to the results, which are focused on: the connection between settlements and environmental resources (mainly water sources and production spaces); least cost paths connecting the network of settlements; relation between least cost paths and trazzere (historical dirt roads); visual control of landscape. The last part is dedicated to the discussion of the results. As will be shown, water sources emerge as an attractor for the Islamic period settlements. This result, if read in conjunction with the rest of the GIS analyses and other studies developed by the Idrisi project, seems to be a possible indicator of the practice of irrigated agriculture in the Islamic period in this area.