[274] e-Perimetron, Vol.1, No. 4, Autumn 2006 [274-286] www.e-perimetron.org | ISSN 1790-3769 Caterina Balletti * Digital elaborations for cartographic reconstruction: The territorial transformations of Venice harbours in historical maps. Keywords: Historic maps; georeferencing; geometric transformations; DTM; modelling. Summary The territory image given by historical cartography constitutes a very concrete base for a diachronical analyses of territory that involves in physical, historical, economi- cal and social elements. The aim of historical analyses through cartography is to un- derstand the present trim of territory, that is the result of antique choices, and to evaluate critically the evolving dynamics: past interventions condition present situa- tion, such as today interventions would condition the future. The basic processing of georeferencing historical maps respect to today cartography makes the individuation and the application of innovative methods necessary to recover the metric and topo- logical content of maps, for a both qualitative and quantitative reading. The research presented in the paper is about a very important theme for the city of Venice and it describes planning and realizing works for safeguarding harbour activi- ties in the past, to support the new interventions. Maps (from the XVth century to our times) are meaningful documents to understand the development of a very delicate part of Venice, which received, during centuries, a constant and extended attention and competence by the Serenissima Magistracy. The work was about the definition and the application of rigorous methods of geo- referencing and of 3d cartographic representations coming from computer graphic field which are not yet employed in ordinary practice. In our society, where visual communications has assumed a essential rule in information’s spreading, cartogram- phic documents, fitted to new technologies, can represent a easily perceptible and ex- tremely incisive message in territory information’s communication. Cartography selected For the study of the territorial transformations of the sea openings of Venice, a selection of maps that cover a period from 1500 to our days was used; these maps are important do- cuments to understanding the evolution of this delicate part of the city of Venice, since the areas object of the study have always been the object of attention and interest by the city magistrature. Historical cartography returns a precise image of the geographic reality of time, unique and priceless evidence of the phenomena that, as Marinelli writes (1881) "no oral or writ- ten description would be enough to describe them." Study of the historical cartography starting in 1500 allows us to describe the great planning and construction jobs of the sea openings guaranteed effective port use of the city of Venice. * Università IUAV di Venezia – laboratorio di fotogrammetria – Circe, s. croce 1624, 30125 Venezia. [balletti@iuav.it ]