The set of equations used in modelling river morphodynamics needs to be (at least) wellposed to be representative of the real natural phenomenon. As we deal with a time dependent process the solution needs to be wave-like to be well-posed. In other words, the solution must have a domain of dependence and of influence. Otherwise, the future river state influences the present solution, which is physically unrealistic. Based on an analysis of the system of equations to model one-dimensional river morphodynamics with unisize sediment and a Chezy-based friction term, Cordier (2011) concluded that the system is always well-posed. Stecca (2014) extended the analysis to a mixture of sediment with 2 size fractions and concluded that under degradational conditions the system may become ill-posed. This result supported the first analysis that found ill-posedness in mixedsize sediment morphodynamics conducted by RIbberink (1987) assuming a simpler model. Here we extend these analyses by adding the effects of flow curvature which creates an intrinsically 3D flow referred to as secondary or spiral flow (Van Bendegom, 1947). In this study the flow is assumed bi-dimensional which implies that the secondary flow needs to be parameterized.
|Publication status||Published - 2017|
|Event||NCR-Days 2017 - Wageningen, Netherlands|
Duration: 1 Feb 2017 → 3 Feb 2017
|Period||1/02/17 → 3/02/17|
|Other||Netherlands Centre for River Studies is a corporation of the Universities of Delft, Utrecht, Nijmegen, Twente and Wageningen, UNESCO-IHE, RWS-WVL and Deltares|