Contrasting approaches in sediment managements along rivers in Piemonte (Italy)

For a long time in-stream excavations of alluvial deposits has been done in Piemonte region (Italy) for sand and gravel mining, altering channels geometry and bed elevation. These anthropogenic activities have substantially altered the sediment yield of many water courses in Piemonte, and the induced effects on rivers (also at present days, such as channel incision and instability, undermining of structures, as well as habitats alteration) forced the local Authorities for a careful sediment management at a watershed basin scale. Therefore, since the nineties, in-stream excavations are prohibited in Piemonte, while at present sediments removal or addition from/to the river bed is mainly intended to obtain river ameliorations, restoring the dynamic equilibrium state of rivers, hazard reduction and flood risk mitigation. For this aim a careful investigation on Piemonte’s rivers planform and profile changes should be done, as a starting point to assess the morphological planar and profile trends in Piemonte’s rivers. The comparison of historical data and the application of numerical models, are useful means for such a kind of analysis. An application of this approach is proposed for the Sesia river (Italy)