ABSTRACT
Bedload transport simulations in the Hasliaare Swiss mountain river were performed along a 17 km long study reach with the one-dimensional numerical model sedFlow. Simulation results of the extreme flood event of 2005 and of annual sediment delivery to the lake of Brienz are in agreement with observations on bedload transport. Increased debris-flow activity was observed in the two steep tributary catchments of Rotlauibach and Spreitgraben during the last ten years, which may be related to climate change. Scenarios of increased sediment input from five tributaries in the future were defined for further simulations. The simulation results show that this lateral sediment input increases the downstream bedload transport in the Hasliaare over a length of about 2-4 km past the last active tributary. No increase in the modeled bedload transport occurs at the end of the study reach.
