The water in the development of Florence (central Italy) between the Roman and the Renaissance ages: the resource and the hazard

Abstract

Pallecchi P. et al., The water in the development of Florence (central Italy) between the Roman and the Renaissance ages:
the resource and the hazard. (IT ISSN 0394-3356, 2010)
The early geomorphological events occurring in the mid valley of the Arno River have determined a suitable setting for the foundation
of Florence. Fluvial processes shaped the future area where Bronze Age people settled down possibly on a seasonal base, followed
by the Etruscans and the Romans that selected the same location as a suitable place for the early Florence town. A network of short
tributaries north of the Arno River represented transverse physiographic barriers and sources of additional water for a stable settlement. Since those times the Florentine people experienced the advantages and risks of such a riverine setting. As for other ancient urban centres, the rises and falls of Florence have been largely driven by the changing political and socio-economic scenarios. The late Middle Age and the Renaissance re-flourishing of the town, following the late Roman Age-early Middle Age depopulation, led to increase in land demand for urban expansion and a growing need of hydropower for the industry. This expansion progressively impacted on the cross-section of the Arno River narrowing it and thus increasing the flooding risk. Two tributaries, Mugnone and S.
Gervasio creeks, were diverted several times as moats along the city walls as they were rebuilt around the expanding town. A comparison of the frequency of floods in the Arno and Tiber rives and the global temperature variation for the period spanning the late Middle Age–Renaissance, indicates that anthropic impact on the Arno River at Florence during the 12th–16th centuries contributed to some catastrophic floods such as the 1333 one that lead to great damage in town and crop failure in the territories. In other periods such as during the cold, humid Little Ice Age between the 16th and 19th centuries, human activities and climatic conditions worked synergistically in determining flooding hazards.