FLOW PROCESSES ON ALLUVIAL FANS IN THE EASTERN ITALIAN ALPS

A method based on morphometric criteria was devised to assess in a fir st approximation the flow type on alluvial fans in mountainous areas w ithin North-Eastern Italy. Geomorphic and/or sedimentologic evidences identify three classes of fans: debris flow fans, fluvial fans and mix ed fans. A plot of Melton's ruggedness number versus fan slope discrim inates these three groups. The morphometric approach was applied on so me drainage basins, taking into account only Melton's number. Historic al information on past high-intensity flow events confirm the suitabil ity of the method.