Monitoring and modeling Large Wood recruitment and transport in a Mountain basin of North-Eastern Italy

An integrated investigation based on field surveys and GIS modeling is being carried out in the Rienz basin (630 km2, Eastern Italian Alps), to predict large wood (LW) recruitment and transport during large flood events. Mobility and transport distance of LW elements of different size is being monitored through repeated surveys of tagged logs in different reaches of the main Rienz River and in one of its tributaries, the Brunst Creek (11.3 km2). Preliminary results show both mobility and displacement length seem to be highly influence by channel morphology characteristics rather than by hydraulic variables. Potential LW deriving from unstable slopes connected to the channel network is predicted using the SHALSTAB model coupled to a GIS-based connectivity index. Connected LW volumes from the slopes, summed to LW erodible within the river corridors, are then routed through the stream network applying simple Boolean transport conditions.