Dendrogeomorphological investigations of debris flow in the Maritime Alps (Northwestern Italy)

To investigate the spatial and temporal history records of debris-flow activity in the Maritime Alps (Northwest Italy), a dendrochronological analysis was performed in Piano del Valasco and S. Anna di Vinadio sectors These areas are characterized by a high frequency of debris-flow activity and are uniformly covered by Larix decidua Mill. A total of five debris-flow fans were analyzed sampling more than 500 trees. Moreover, a geomorphological survey of the source areas, flow channels and final lobes was performed. The dendrochronological results improve the knowledge of debris-flow occurrence in the Maritime Alps for the last two centuries, confirming some historical records and adding new events. Around the middle of the last century (1948-1950) huge debris flows affected the analyzed fans, destroying most of the trees. Eventually, several others events are recorded, most of them previously not documented in this region.