Application of a new cellular model for bedload transporting extreme events at steep slopes

A cellular model for bedload transport at steep channel gradients and alluvial fans has been developed to simulate lateral distribution of erosion and deposition on alluvial fans of mountain streams. The cellular model, named FluviSed, applies a quasi-steady-state routing of a flood hydrograph over a rectangular grid. Bedload transport is calculated and the morphological changes are updated after each time step. FluviSed is designed to complement existing one-dimensional bedload transport simulation tools by using their outcome as an input for the simulation of inundated areas. The model has been evaluated against TomSed, a one-dimensional bedload transport model. Further, a back-calculation of a laboratory bedload experiment and a real flood event from 2005 at Schnannerbach in Austria are provided to test the model's suitability for reproducing morphological changes caused by flood events at high channel gradients.