NUMERICAL MODELLING OF THE EFFECTS OF RIVER DISCHARGE REGULATION ON THE MORPHOLOGY AND SEDIMENT TRANSPORT DYNAMICS IN A SHALLOW ESTUARY

摘要

This paper presents an analysis of the sediment transport dynamics in the inner part of the Arousa estuary due to tidal and river currents under non-stratified conditions. For this purpose we use a 2D sediment transport model coupled to a 2D depth-averaged shallow water model and a bed-deformation module. The sediment transport model includes non-equilibrium bed load and suspended load formulations. Turbulent stresses computed with a depth averaged mixing length model are considered in the hydrodynamics as well as in the suspended load equation. A bed slope correction is included in order to account for the effects of gravity on the bed load rate and direction. The numerical model is used to analyse the influence of the river discharge on the sediment transport dynamics of the inner estuary for different tidal ranges (neap, mean and spring tides).