Geomorphological evolution of the plain between the Livenza and Piave Rivers in the sixteenth and seventeenth centuries inferred by historical maps analysis (Mainland of Venice, Northeastern Italy)

The ancient hydrographical network and geomorphological framework of the fluvial and coastal plain encompassed between the Livenza and Piave Rivers in the mainland of Venice (Northeastern Italy) were reconstructed, based on historical maps, georeferenced, and overlaid on available geomorphological maps and aerial photographs. A selection of 59 maps was accurately analyzed (32 from the sixteenth century, 31 from the seventeenth century, and 6 from the eighteenth century). They were selected by author, commitment, date, and scale, from among more than 1000 maps edited by Savi e Esecutori alle Acque (the 'hydrographical' service during the Republic of Venice) in the 16th and seventeenth century. The most representatives (7 from the sixteenth century and 6 from the seventeenth century) were georeferenced and redrawn. Finally, four 1:50.000 maps were created, picturing the ancient morphology and hydrographical network in the years 1550, 1600, 1650, and 1700, covering an area of about 130 square kilometers. Geographical information was compared with historical documents and geological, geomorphological, and geochronological data. Further comparison of geodetic maps from the eighteenth to the twenty-first century produced new maps with important information on the paleogeographical and environmental framework across two centuries, and particularly on the artificial diversion projects performed by the Venetian Republic, their effectiveness, and the geomorphological changes both related to human intervention and recent climatic changes.