Identification, computation, and mapping of anthropogenic landforms in urban areas: Case studies in the historical centre of Genoa, Italy (UNESCO World Heritage)

Urban geomorphology is a recent discipline that has gained a great deal of interest amongst the scientific community also for its clear connection with the concept of Anthropocene. The identification of anthropogenic landforms in an urban area requires a multidisciplinary approach, mostly using multi-temporal map comparisons, direct and indirect geognostic surveys, and detailed study of the urban landscape. Mediterranean cities have a particularly complex history: their original settlement usually dates back to the medieval period, but often to more ancient, occasionally even prehistoric, times. The result is an urban landscape characterised by modified natural landforms, but above all by anthropogenic landforms linked to the stratification of various urban phases. Reconstructing the landforms before major anthropogenic impacts of the last centuries is a particularly complex operation, and scientific research appears in its early stages. In this research, we introduce examples of the reconstruction of natural landforms in the historic centre of Genoa, a port city that experienced a peak of expansion in the Middle Ages and the Modern Age. The results obtained on four pilot areas highlight significant and previously unknown anthropic modifications and the associated landforms in the urban landscape. Large excavations, fills supported by ramparts, and sea embankments have been identified and quantitatively evaluated using a mixed approach between different disciplines: historical geography, geomatics, physical geography and geomorphology, and engineering geology. This methodology may be applied to other Mediterranean and extra-European urban contexts and may contribute, on the one hand, to the identification of potential geomorphological risks in urban areas and, on the other hand, to the use of urban landscape forms for geological heritage and geodiversity development activities.