Impact of sea level rise on the hydrodynamic regime and sediment distribution in the Dong Nai-Sai Gon River basin of Southern Vietnam

Sea level rise (SLR) significantly impacts morphodynamics, altering hydrodynamics, sediment transport, and riverbed morphology. This study examines these effects in the Dong Nai-Sai Gon River (DNSG) basin, focusing on the Soai Rap River mouth. Using an integrated numerical model (TELEMAC-2D–SISYPHE–TOMAWAC), simulations were conducted under three SLR scenarios: baseline (SCE0), SLR+0.5 m (SCE1), and SLR+1.0 m (SCE2). Results indicate erosion in Zone 1 (upstream), sediment balance in Zone 2 (midstream), and deposition in Zone 3 (estuary and coastal areas). Regression-based linear equations were developed to understand the sediment deposition relationships among the zones under varying SLR conditions. We have discovered new insights into sediment dynamics, providing predictive tools for sustainable sediment management and adaptation to SLR in estuaries. Additionally, this work contributes to understanding regional morphodynamic responses to SLR and informs strategies for managing sediment resources in estuarine systems.