Uncertainty quantification in shallow water-sediment flows: A stochastic Galerkin shallow water hydro-sediment-morphodynamic model

All shallow water hydro-sediment-morphodynamic (SHSM) models are prone to uncertainty arising from inadequate representation of the underlying physics and error in input parameters. At time writing, most SHSM solve deterministic problems, whilst studies quantification remain rare. Here a new stochastic model is proposed, extended well-balanced, operator-splitting-based, generalized polynomial chaos Galerkin (gPC-SG) solver one-dimensional hydrodynamic equations. A series probabilistic numerical tests carried out, corresponding idealized dam break flow over fixed bed laboratory experiments flow-sediment-bed evolutions induced by sudden landslide failure. The proposed modelling framework shows promise for water-sediment flows erodible beds.