Flooding of the Saguenay region in 1996. Part 1: Modeling River Ha! Ha! flooding

This paper presents an application of the model UMHYSER-1D (Unsteady Model for the HYdraulics of SEdiments in Rivers One-Dimensional) for the representation of morphological changes along the Ha! Ha! River during the 1996 flooding of the Saguenay region. UMHYSER-1D is a one-dimensional hydromorphodynamic model capable of representing water surface profiles in a single-river or a multiriver network, with different flow regimes considering cohesive or non-cohesive sediment transport. This model uses fractional sediment transport, bed sorting, and armoring along with three minimization theories to achieve riverbed and width adjustments. UMHYSER-1D is applied to the Ha! Ha! River (Quebec, Canada), a tributary of the Saguenay River, for the 1996 downpour. The results permit forcing data verification and prove that some cross sections are not the right ones. UMHYSER-1D captures the trends of erosion and deposition well although the results do not fully agree with the collected data. This application shows the capabilities of this model and predicts its promising role in solving complex, real engineering cases.