Mg. Villagrán-Valenzuela, Mauricio

Estuaries are dynamic ecosystems with crucial environmental, economic, and social functions, driving extensive hydro-morphological research supported by numerical modeling. This study systematically reviews estuarine modeling applications over the past 15 years to identify commonly used tools, model configurations, and validation strategies, to examine regional trends in the application, and to explore and discuss the relative emphasis on hydrodynamic, sediment transport, and morphological modeling within the selected studies. Following the PRISMA 2020 methodology, a comprehensive search in Scopus and Web of Science identified 3926 articles, from which 197 met the eligibility criteria. Each study was analyzed to assess modeling software, mesh types, dimensional configurations, and validation parameters. Results indicate that DELFT3D is the most widely used tool, followed by TELEMAC and FVCOM, with a preference for two-dimensional models and structured meshes. Model accuracy, assessed through Skill Scores, confirms their reliability in representing estuarine dynamics. Additionally, findings reveal significant geographical disparities, with China leading research efforts, while Latin America and Africa remain underrepresented. This gap highlights the need to expand modeling efforts in these regions to enhance estuarine management and resilience. Strengthening numerical modeling in diverse contexts will improve the predictive capacity of hydro-morphological processes, supporting sustainable decision-making in estuarine environments.

Detailed video images and ADCP measurements were used to describe the processes of suspended sediment transport by the Mataquito River into the Pacific Ocean. It is found that, in the absence of fluvial flood discharges, suspended sediment transport to the sea only takes place during low tide periods and it is characterized by pulses of different frequencies that in turn are related to the spatial velocity distribution at the river inlet. It was observed that at low tide the highest velocities are near the mouth of the river, presenting an heterogeneous spatial distribution. In this high speed zone, we hypothesized the shear stresses are big enough to re-suspend fine sediment that is transported into the ocean by the main river current. A simple conceptual explanation based on these findings is presented, seeking to explain the observed dynamic equilibrium of the Mataquito River inlet after the significant alterations produced by the 2010 M8.8 earthquake and tsunami.