The Middle Valley of the Sinni (Italy, Southern Basilicata). Analysis of Visibility Between Medieval Fortified Sites (11Th-14Th Century A.D.)
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Journal of Research and Didactics in Geography (J-READING), 2, 7, Dec., 2018, pp. 83-93 DOI: 10.4458/1682-08 The middle valley of the Sinni (Italy, southern Basilicata). Analysis of visibility between medieval fortified sites (11th-14th century A.D.) Valentino Vitalea a Dipartimento delle Culture Europee e del Mediterraneo (DiCEM), University of Basilicata, Matera, Italy Email: [email protected] Received: April 2018 – Accepted: November 2018 Abstract Viewshed Analysis, or visibility analysis, allows you to evaluate the range of the observation area from a given location, tower, lookout, the creation of a hypothetical model of how these sites communicated and related to each other. The study, conducted as part of the author’s doctoral thesis, examines the ancient medieval landscape in the middle Sinni Valley in southern Basilicata, starting from the development of the entire system of fortifications between the municipalities of Valsinni and Colobraro, in the eastern portion, with the two respective fortresses of barrage locality “Il Pizzo” and locality “Cozzo Madonne della Rocca”, until you reach the innermost part in a Tyrrhenian direction westwards with the fortress of the “Castello di Seluci”, now in the municipality of Lauria (PZ). In the case of fortified settlements in the hinterland of this area, a central function was carried out by Chiaromonte (PZ), the center of the county already under the Norman Clermont family during the 11th century A.D. and also during the Regency of the Sanseverino family in the 14th century A.D. With these premises it is fundamental not only to highlight the area immediately visible from each site, but also to understand the level of intervisibility that had to exist in the settlement network of this given territory between the 11th and 14th centuries A.D., the moment when the entity and future vocation of this precise territory are consolidated. Keywords: Drone, Medieval Archaeology, Medieval Topography, Norman, RPAS, Viewshed Analysis 1. Introduction. Archaeological survey historical picture of particular interest. The area activities extends from the Ionian coast in the east to the slopes of Mount Sirino in the west and is crossed The medieval settlement system of the Sinni by the river Sinni; inside it included the territory valley preserves significant traces of structures, of Mercourion and Latinianon, particularly whose chronological limits take into account the involved in the development of religious central centuries of the Middle Ages, from the settlements of both Greek and Latin rite as well th end of the ninth to the 15 century A.D., as being affected by the parallel phenomenon of characterizing a geographical area with a Copyright© Nuova Cultura Italian Association of Geography Teachers 84 Valentino Vitale the encastellation that began here from the 10th reconnaissance campaign; 2) repeated site to 11th century A.D. Just from the 11th century inspections to acquire GPS points to check the A.D. the settlement typology in this territory evidence at different times of the year; 3) changed compared to the previous period, continuous site inspections to perform flights passing from a scattered rural settlement model using RPA of the evidence identified. The to the intensification of the demonic settlement opportunity to replicate the data was on the summit hills (Sogliani, 2010, pp. 171- fundamental considering the visibility of places 195; Sogliani, 2017, pp. 265-312). The strong based on the rich vegetation in different seasons centralisation in a dominant position is indicated of the year. All this evidence is located in places by the spread of the fortified settlement system where no agricultural activities are practised, so in Norman times, a phenomenon in this area, as the surrounding land is currently used for in the rest of the region, facilitated by the forestry purposes and with very little visibility absence of large urban centers. Among the (Brughmans and Brandes, 2017). The experience defensive and lookout settlements abandoned with satellite georeferencing and positioning between the 14th and 15th centuries A.D. and no systems is now a well-established methodology longer repopulated are the towns of “Catarozzo” of investigation in archaeological research. in the municipality of Francavilla in Sinni (PZ), These phases were carried out with the help of a “Castello di Seluci” in the municipality of Leica GNSS GS08 Plus GPS Rover system, Lauria (PZ), “Il Pizzo” (Valsinni, MT) and which made it possible to carry out the most “Cozzo Madonne della Rocca” near the centre of precise mapping of the investigation. The same Colobraro (MT). The portion of territory being RPA Phantom 4 DJI used for aerial investigated by this research has already been reconnaissance is equipped with a GPS sensor partially examined during the years 2001-2003, with accuracy between +/- 20-30 cm (the by bringing together the data in the publication possibility of flight was guaranteed in of the “Archaeological Map of the Sinni Valley” compliance with the legal regulations for RPAS: (Quilici and Quilici Gigli, 2001). These Valentino Vitale operator RPAS for specialized volumes, still indispensable for the knowledge critical and non-critical operations No. 9981). of the elements that constituted the settlement of The shots and photoplans taken through aerial this area, so far represent an underestimated acquisition carry all the information of a ground archaeological fact in the medieval age. The GNSS system, allowing the implementation of sample acquired in years of field research in the the two data directly on the GIS (Campana, middle Sinni Valley, in terms of quantity and 2013). The possibility of earthing the hook complexity, always leads to the same result, just points detected by the GNSS system has made it as in numerous national and international possible to correct the positioning error offered experiences 1. The following considerations by the RPA and georify the orthophotos made represent part of the research activities carried with millimeter precision. The GNSS system out by the author in the area between the allows sub-centimetric precision positioning in municipality of Valsinni (MT) and the eastern areas such as those surveyed with poor shrub limits of the municipality of Lauria (PZ) in the vegetation on the crests of walls. The possibility locality of “Castello di Seluci”, on an to work with an RPA system with integrated investigated territory that extends for about 500 GPS built by DJI with positioning of shots km2 distributed in an area of more than 13 usually below 30 cm, makes it possible data to municipalities in southern Basilicata along the obtain results in the georeferencing phase that middle Sinni valley. The data were taken from summed up do not reach imperfections that go the results of the author’s PhD research beyond a couple of centimeters of error, This conducted between 2015 and 2017, entitled: value can be considered optimal for the “Settlement systems, organization and evolution positioning works of large architectural of the medieval landscape in southern Basilicata: complexes distributed, among other things, on the middle Sinni valley. The forms of secular non-flat surfaces, thickly located at high and ecclesiastical power between the 10th and altitudes along rocky ridges. The feedback 15th centuries A.D.” (Vitale, 2018). The data between different photographic series was of collection phase was divided into: 1) a surface great help in identifying and understanding the Copyright© Nuova Cultura Italian Association of Geography Teachers Valentino Vitale 85 tracks. For the aerial-photogrammetric coverage development of research in the middle Sinni of the territories in question, reference must be Valley includes numerous information plans, all made to the flights of the Basilicata Region and in vector format (Figure 1). to the IGM. The GIS system used for the Figure 1. Chiaromonte (PZ). GIS of medieval evidence. Graphics processing by the Author. digital structure used in a GIS to represent a Most of these are now available through the three-dimensional surface) of the area, a model RSDI Basilicata portal (http://rsdi.regione.basili- that the regional cartography (RSDI Basilicata - cata.it/web/guest/mappe-in-linea). In particular, https://rsdi.regione.basilicata.it/) does not the latter provides cartography useful for the provide at the moment. research work in question such as: administrative limitations; land use map; geolithological map; 2013 and 2014 2. Viewshed Analysis between fortified orthophotos; DSM and DTM (both with a resolution of 5m); regional technical map of sites: questions of method 2013. The sections can be downloaded in The interest in the medieval world in the georeferenced TIFF format for orthophotos, middle Sinni valley, in the problems related to DTM and DSM, while in vector DXF format for the management and organization of the all the above listed types of cards and refer to territory, a place of contact between different the WGS 84 UTM 33 N coordinate system. A people and cultures, makes it possible not only digital model of the land at 5m of the entire to know the historical / settlement of this investigated area was generated from the level territory but to understand a series of pieces of curves of the regional technical cartography evidence that are clearly recognizable on the 1:5.000 (CTR), thus creating the TIN (the TIN territory in their primary vocation in the defined as “Triangulated Irregular Network” is a historical