A vegetation roughness model to evaluate flood risk along Secchia river

In January 2014, a serious flooding event (due to a levee breach) occurred in the towns of Bastiglia and Bomporto, located in the Modena Province (Italy) along Secchia River. Since then, concerns have increased about the role of vegetation in Secchia river channel during big floods. A detailed characterization of riparian vegetation features has then been produced by the Po River Interregional Agency (AIPo) to point out critical issues about current vegetation pattern along Secchia river banks and possibly plan a maintenance - remediation strategy. This characterization report constitutes a good basis for a hydrodynamic modelling work; a 1D finite-volume model with mobile bed, accounting for the influence of different vegetation patterns and densities on flow resistance has been applied to a 60 km long stretch of Secchia river, to support management choices and possibly check the effectiveness of a proposed vegetation plan in reducing flood risk. The agreement of the simulation results for a real flood event with gauged values is satisfactory.