A capital between lands and waters: reconstructing the evolution of the alluvial landscape around Ravenna through digital and field geoarchaeology

The thesis studies the geomorphological transformations that have occurred in the hinterland of Ravenna in the last three millennia by employing a combination of digital and field geoarchaeological approaches to understand how landscape transformations have influenced and have been influenced by human-environment relationships. The study area, corresponding to the southeastern portion of the Po Valley, has undergone intense changes that have led to the burial of palaeosurfaces and associated archaeological sites. Human actions have also intensified these natural processes via extensive land reclamation. Thus, strong geomorphological biases hinder the reconstruction of past settlement patterns. To shed light on the evolution of this highly dynamic floodplain landscape, I employed a multidisciplinary and multiscale approach combining scientific data with interpretations of historical and cartographic sources. After an introductory part on the geomorphological configuration and the historical-archaeological dynamics of the study area, six chapters follow, each focusing on a methodological application, related datasets created/employed and the results obtained. The methodologies are geomorphometric analysis, remote sensing, discussion of cartographic and medieval written sources, analysis of archaeological data, collection and interpretation of geoarchaeological data, and data integration for palaeoDEM modelling. Although these methodologies have been treated separately, the knowledge that each one generated gradually adds up to the previous ones to shed light on the transformations that have taken place in the study area. From a methodological point of view, for the first time established approaches were applied systematically over the entire study area, leading to the mapping of hundreds of fluvial remains, several abandoned medieval fortified sites, and possible traces of unique field systems of various chronologies. In addition, I was able to shed light on the land reclamation process in the area, proving that it began as early as the Middle Ages and continued into the 20th century CE. At the same time, all the collected data were used to push the limits of palaeoDEM modelling applied to an extensive and biased context, testing a strategy to improve further the results obtained. In this way, it was possible to create models of the archaeological potential and palaeogeographical maps for four different chronological periods. Finally, revised and newly acquired knowledge abled me to rewrite a geoarchaeological history of the rivers flowing through the hinterland of Ravenna, the real pivot of the vicissitudes of this territory. Through the evidence of rectification, reclamation and natural and non-natural avulsions, it is possible to understand very well the impact that local communities have had in shaping the current landscape