ABSTRACT
In the present paper is discussed the performance of three different 1-D hydro-sedimentary numerical codes: (i) HEC-RAS (Corps of Engineers of the US Army), (ii) Telemac-Mascaret/Courlis (EDF) and (iii) Mage/AdisTS (Irstea). Their hydrodynamic module is based on similar equations (1D Shallow water equations). However, the sedimentary modules often differ in the description and modelling of parameters such as bed shear stress representation, grain size distribution, or bed evolution and involve different input data. The three numerical codes were used to simulate the 2016 dam flushing operation on the French Upper Rhône River, which is characterized by three different phases for the specific case of the Seyssel dam reservoir: (i) sediment deposition, (ii) erosion and (iii) propagation. The calibration of the hydro-sedimentary models was performed using SPM loads (from calibrated turbidity records), particle-size measurements and bathymetric data. A sensitivity analysis was performed for the most relevant parameters of each software.
