Sediment transport and morphodynamics at salt marsh boundary in the shallow bay during cold front passages

Understanding the processes of wetland boundary morphodynamics is critical to evaluating the vulnerability of wetlands. Specifically, analysis of changes in sediment supply at the wetland boundary due to the effects of global sea-level rise and local subsidence provides a more comprehensive depiction of future changes in coastal wetlands. This requires analysis through numerical modeling along the wetlands area to provide predictive information for future scenarios. However, sediment transport and morphological dynamics in adjacent bays have not been incorporated into regional models of wetland evolution. The study investigates the short-term sediment transport processes in a highly resolved wetland boundary within Galveston Bay during cold front passages. In-situ measurements verified the hydrodynamic and waves conditions at the salt marsh boundary during the period of two cold front passages. The model showed that the circulation of sediment fluxes to Galveston Bay was increased during the cold front passage. In addition, extensive wetlands flooding caused by cold fronts significantly affected the sediment supply to the wetlands. The sea-level rise adaptation of the salt marsh platform was verified by comparing the baseline and relative sea level rise models.