Cowles, G.W., 2013. A block-structured adaptive mesh refinement solver for morphodynamic modeling.

An adaptive solver for two-dimensional horizontal morphodynamic modeling studies is presented. The method employs an established augmented Riemann solver to compute unsteady, two-dimensional flows over arbitrary topography. An Exner equation is used to model the evolution of the bed using several common load formulas. The morphodynamic coupling is stabilized using an upwind approach. The scheme is implemented in a highly scalable block-structured adaptive mesh refinement framework. The resulting solver is well balanced and resolves the dry state while maintaining nonnegative depth. Idealized tests include comparison with exact Riemann solutions for dam break problems and an analytical solution for the migration of a one-dimensional sinusoidal bedform. Practical tests include the migration of a Gaussian perturbation and the evolution of flood and ebb shoals in a tidal inlet. The solver is benchmarked on a modern multiprocessor machine to quantify the scalability of the approach.