FIRENZE: IL SUO IMPATTO SULL’EVOLUZIONE GEOMORFICA DELL’AREA

Abstract

Coli M., Agili F., Pini G. & Coli N., Firenze: its impact on the landscape. IT ISSN 0394-3356, 2004
In this study we have applied computer digital tools in order to show the changes of the Florence country area in these last twenty centuries during the development of the city of Florence, which was founded by Julius Caesar in 56 b.C. as colony for his veterans.
Florence was settled in accordance to the sun with a N-S and W-E street grid. Florence was placed in an upraised area, between the
Arno river and the Mugnone creek. That site allowed the control of the ford on the Arno river, along the main path from the Tyrrhenian
coast to the Adriatic one. At those times, the natural landscape, constituted by the wandering Arno river and its tributaries as by marshlands and bogs, had already been changed by about two centuries of land use by Romans. Romans used to reclaim marshlands and bogs by means of “centuriazione”: squared grid of ditches and roads which deeply marked the country. Traces of the centuriazione are still now visible, it drove and still drives the country and outskirt onsets. Centuriazione was oriented according to the ground natural set (NW-SE and SW-NE). The development of Florence in Roman time (in the III Century, Florence numbered about 50.000 people, and dropped down to 1.000 in the Bizantine age, VI Century) and in the late Medieval and Renaissance time (when Florence numbered about 100.000 habitants) was along the suburbs. Suburbs where aligned along the outgoing roads and in order to enclose suburbs, the successive rings of the city walls gave to Florence a pentagonal shape. The last city walls (XIV Century) were mostly destroyed in the late XIX Century to give space to the ring of the avenues and to new quarters outside. These new quarters were set oriented parallel to the destroyed city walls. The new outskirts built in the last fifty years in the country surrounding Florence were still settled according to the old trace of the centuriazione. During this time span, the creeks were put as moat and progressively diverted by their natural path until they were totally channelled or covered. The Arno river was progressively rectified, narrowed and banked. After the fall of the Roman Empire, marshlands and bogs taken newly place which were progressively reclaimed since XI till XX Century. In event of large floods the Arno river course became as large as it used to be.