A first approach to modelling fine-sediment dynamics in the Santa Cruz River estuary, southern Patagonia

Santa Cruz River Estuary (SCRE), located in Santa Cruz Province, Argentina, presents an area of 141 km2, receiving river discharges of both the Santa Cruz and Chico River, with mean values of 715 m3/s and 25 m3/s respectively (Bindelli, 2018) and containing visible amounts of clay sediment. It also presents a semi-diurnal and macro-tidal regime that can reach a tidal range of up to 12 m. As stated in Dinápoli et al. (2024), it is part of a region of astronomical dominance, with river discharges and wind having minor influence in hydrodynamics. The sediment plume can be observed in satellite images, presenting a clear tidal influence due to the estuary’s high tidal range, and presumably some seasonal influence as well, due to the river’s seasonal regime. As for the fine sediment characterization, samples were taken from the estuary as part of an Environmental Assessment for engineering works on the area, presenting Kaolinite as the main component, followed by some presence of quartz. In this work, a coupled hydrodynamic and particle tracking model is used to describe the macro-tidal dynamics of the SCRE. Then, as a first approach to modelling the fine-sediment dynamics, a comparison of these results to SENTINEL 2 satellite images is made.