Reconstructing the physical landscape of the Rieti urban area towards historical sources and cartography

The ancient Roman city of Rieti (Reate) developed on the south-eastern edge of the homonymous plain. It stood on a small cliff of continental carbonate deposits produced by cold mineralised waters (calcareous tufa). Rieti is also known as the “City of Waters” or “the Venice of Central Italy” due to the river Velino, nearby springs, and a network of artificial canals, now buried or channelled underground. Rieti can be considered an excellent example of how historical cartography can contribute to reconstructing the physical landscape of urban areas. Among the cartographic sources of particular importance is the Gregorian Cadastre of the Papal States, built in sice1819 and adopted in 1835. This geometric cadastral particle, appropriately georeferenced in a GIS environment, if compared with the cartographic productions of the late nineteenth century, as the first edition of the Italian Topographic Map and other post-unitary cadastral instruments, allows a diachronic study on the urban and rural landscape evolution of the territory of Rieti. Rivers and channels crossed the old town since the Middle Ages, and each time the city walls expanded, new ditches and canal systems were created, accompanying the progressive development of the urban area.