A Rapid Method for Modeling Transient River Response Under Stochastic Controls With Applications to Sea Level Rise and Sediment Nourishment

Recent analysis of equilibrium and quasi-equilibrium channel geometry in engineered (fixed-width) rivers has successfully shown that two temporal scales can be distinguished, with quasi-static (long-term) and dynamic (short-term) components. This distinction is based on the fact that channel slope cannot keep pace with short-term fluctuations...

The Quasi-Equilibrium Longitudinal Profile in Backwater Reaches of the Engineered Alluvial River: A Space-Marching Method

An engineered alluvial river (i.e., a fixed-width channel) has constrained planform but is free to adjust channel slope and bed surface texture. These features are subject to controls: the hydrograph, sediment flux, and downstream base level. If the controls are sustained (or change slowly relative to the timescale of channel response), the...

A Well-posed Model for Mixed-Sediment River Morphodynamics

The mixed-size character of sediment is a necessary property to ex- plain physical phenomena such as downstream fining or the presence of armor layers. The active layer model was developed to model mixed-size sediment in river morphodynamics. This model assumes that the topmost part of the bed, the active layer, has no vertical stratification...

The morphodynamic equilibrium state of a river in backwater dominated reaches

When rivers are forced by statistically invariant boundary conditions (i.e. an upstream water discharge, upstream sediment discharge and downstream base level that fluctuate around constant mean values), and are not subject to any forcing with a temporal trend (e.g. no uplift/subsidence, no sea-level rise), they tend to a morphodynamic...

Ill-posedness in modelling 2D river morphodynamics

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...