Long‐Term Interactions between the Roman City of Ostia and Its Paleomeander, Tiber Delta, Italy

Abstract

This study examines the long term interactions between the well-known Roman city of Ostia and a river meander. Located at the mouth of the Tiber River, Ostia was a major harbor city that connected Rome to the Mediterranean Sea. Based on aerial photography and boreholes analysis, the paleodynamics of the Fiume Morto's paleomeander are understood to be linked to the urban evolution of the city of Ostia. Four periods of evolution have been identified as a result of this interdisciplinary work: (1) the foundation of Ostia's urban center, in the 4 th -3 rd century BC, occurred when the meander already existed;(2) between the 4 th century BC and the 3 rd century AD, human/environmental interactions contributed to the compound growing of the meander which possibly eroded an important Roman road linking Ostia to Rome; (3) from the Imperial period until the meander was cut off in AD 1557-1562, the constricted meander channel at the apex led to the stability of the downstream river channel; (4) the cut off of the paleomeander was completed in 1562, leading to the filling of the paleochannel. These successive phases of channel evolution mark changing fluvial risks from the Roman period to today.

River channel evolution and tsunami impacts recorded in local sedimentary archives – the ‘Fiume Morto’ at Ostia Antica (Tiber River, Italy)

“…Stratigraphic records from the eastern Fiume Morte, (cores MO 1 and MO 2; Salomon et al ., ; Fig. ) correlate well with present results.…”

“…Also, Salomon et al . () present an intermediary sand layer (unit C2) which seems to correlate well with subunit B2 at site TEV 3A, representing some fluvial influence on the lagoonal system. Yet, lagoon‐type deposits set in at 9·5 m b.s.l.…”

“…The data confirm that an early form of the meander, as suggested by Salomon et al . (), was already established when the castrum at Ostia was founded.…”

“…As shown by Salomon et al . (,b), the former Tiber meander Fiume Morto represents an adequate geoarchive to achieve the main objectives of this study.…”

“…Based on a set of vibracores drilled where the former course of the Fiume Morto intersects the Decumanus of ancient Ostia of the 4th to 3rd Centuries bc , Salomon et al . (,b) presented a first study on the sedimentary record of the Fiume Morto itself in an archaeological context. Additionally, one core from this set was used to reconstruct vegetation changes by means of pollen analyses (Pepe et al ., ).…”