Value of ancient cartography for geoenvironmental purposes. A case study from the Po River delta coast (Italy)

Abstract

A set of four large-scale pregeodetic maps was studied. They depict the Po River delta ancestor in the late-16^th century AD (before the year 1604), an extremely important area for the geoenvironmental and historical evolution of Northern Italy at the beginning of the Little Ice Age. The maps are very detailed and complex. This characteristic involves some problems relating to accuracy and comparison with present-day cartography. This first attempt at map georeferencing is required in order to make possible original coastline location in areas that do not exist today because of sea erosion. Nevertheless, a further attempt is already being made for achieve a better understanding of the maps. Inner details and manifest errors were highlighted so as to better appraise the reliability of the maps and the authors’ survey methodologies. Furthermore, a particular and highly peculiar geomorphological object (i.e. an offshore megabank) was analyzed and rejected as a completely untrue ancient landscape tract. Hence, the really interdisciplinary character of this kind of studies must be ever taken into consideration and critical map analysis should not merely be seen as a useless and time-consuming analytical tool since the fortuitous preservation of ancient documents can dispel wayward interpretations in geoenvironmental reconstruction.