Dune bed statistical analysis using multibeam echosound survey data

In alluvial river the bed forms represent the most relevant features governing flow resistance and bedload transport, they can have a wide range of geometry patterns corresponding to the same hydrometric condition. Bed forms influences the kinematic field, the flow resistance, the conveyance, and the stability of the fluvial infrastructures. Morphological changes and the bedload component can be evaluated considering the changing flow conditions, the geometry of the bedforms and their downstream migration. Different scales of bedforms may coexist within the channel, and so ripples are superimposed on the back of the primary forms. Bed undulation can be analysed through spectral analyses approach. In this study, Multi-Beam Echo-Sounder (MBES) surveys carried out in Po River (Italy) are considered. Combining bed surface DTM and spectral analysis, the filtered bed undulation is obtained, statistic geometrical properties of the bedforms and their kinematic are analysed.