Flood risk estimation through document sources analysis: the case of the Amalfi Rocky Coast

A systematic investigation of historical sources was carried out analysing both published and unpublished sources since XVI century. The great variety of historical sources made it necessary to formulate an ad hoc scientific procedure that would above all take into consideration the document's intrinsic quality in order to minimize spurious data. In this task, the level of information was decisive: we were able to carry out spacetime identification, estimate the area affected, the type of damage to public and private structures, and the geological effects induced. On the basis of the size of the areas hit by flooding, the type of effects induced on the urban and physical environment and the recurrence intervals, we estimated the magnitude of the events. The latter measure is undoubtedly fundamental for hydrogeological risk assessment and for estimating the return times of extreme events in the area.