Multitemporal analyses of anthropogenic changes to the drainage network in urban areas: a case study in Rome (Italy)

The geomorphological map of Rome city centre, first published in 2016, is one of the most representative case studies for urban geomorphology, due to the widespread anthropogenic changes to landscape caused by human activities over the city’s millenarian history.

The today topographical and hydrographic setting is therefore the result of both natural and anthropogenic processes, which have occurred and intertwined over time. In particular, the most relevant human interventions affect the hydrographic network in the eastern area of the city, where it firstly arose and developed and where resource abundance and at the same time water management and supply needs were more relevant.

Before significant land-use changes had started since the roman time, this area was drained by the most important left tributaries of the Tiber River, such as the Aniene River, the main watercourses of the city, the Nodicus-Aqua Mariana stream, the Almone River, the Grotta Perfetta and the Vallerano streams. Their courses became culverted or were diverted. Emblematic is the example of the Nodicus valley, standing between Aventino and Palatino historical hills, and the Rivo Aqua Mariana artificially streaming into the Nodicus drainage basin since the 1122 a.D. diversion, which probably restored the original Nodicus hydrographic system.

This work aims at presenting the first relevant results towards the reconstruction of the main topographic transformations on the Tevere River hydrographic left area by analysing the current drainage network and its anthropogenic modifications. The methodological approach consists of multidisciplinary bibliographic research supported by multitemporal geomorphological and topographical analyses. The results of this work are summarized in the map of the changes to the hydrographic network.