A geographic database for flood risk assessment, integrating diachronic data, is proposed, considering as study area the Versilia river basin (North - West Tuscany), prone to frequent flood events. Particularly, beginning form cadastral maps of the first half of the XIX century, the diachronic data of land use have been processed, and the soil hydrologic characterization has been carried out. The analysis deals with the integration of current cartographic data and historical data, as described above extracted from ancient maps and documents recently discovered in the archive of the Regional Office for Territory Protection, of Lucca (Italy). The ancient folder holds, in a detailed way, the studies carried out by the technicians of the “Royal Civil Engineers Corp” of Lucca, for the Versilia river basin recovery, after a disastrous flood event occurred on September 25th, 1885. The analysis points out the recognized significance of the knowledge of past events and history of the territory and the importance of a multidisciplinary approach, connecting the instruments of historical geography with those used for applied sciences.