Recalculation of bedload transport observations in Swiss mountain rivers using the model sedFlow

Abstract

Abstract. Only few validated numeric models are available for the simulation of bedload transport dynamics in mountain streams. In this study, the recently developed modelling tool sedFlow has been applied to simulate bedload transport in two Swiss mountain streams. It is shown that sedFlow can be used to successfully reproduce observations from historic bedload transport events with reasonable parameter set-ups. The simulation results shed light on the difficulties that arise with traditional flow resistance estimation methods when macro-roughness is present. In addition, our results demonstrate that greatly simplified hydraulic routing schemes, such as kinematic wave or uniform discharge approaches, are probably sufficient for a good representation of bedload transport processes in steep mountain streams. The influence of different parameters is qualitatively evaluated in a simple sensitivity study. This proof-of-concept study demonstrates the usefulness of sedFlow for a range of practical applications in alpine mountain streams.