A methodology to re-profile areas involved in debris flow phenomena

Rio Velt watershed is located in the municipality of Sauris di Sotto, in the Friuli Venezia Giulia Region and is made by three subwatershed that have their confluence upstream the crossing of provincial road that take to Sauris di Sopra. In Schneider tales during 1800, there were witnesses of possible debris flow phenomena in the area. On this basis and on geomorphologic evidences, an outline of the event has been realized. This perimeter has the ID (Identification Number) 0301070200 inside the landslide Italian inventory called I.F.F.I. (Inventario dei Fenomeni Franosi in Italia) and has been adopted in second instance from the P.A.I. project (Piano di Assetto Idrogeologico). The outlined region represent a wide area in which are located different infrastructures as a camping place, a sport center and part of the province road. The present work would like to highlight the importance of using of objective methodologies to outline the debris flow phenomena and this permit to obtain scenarios of event that reconstruct the verified events or to create new scenario for area that has not yet been involved in alluvial events in which there are not data available for a back analysis process. So, in the studied area many simulations have been realized that allowed to identify with more awareness a possible event in order to modify the actual outline and to make it acceptable for the P.A.I. Project.