LAUSR

This study presents a new approach to modeling marsh evolution. The Tidal Marsh Model (TMM) has been developed as a module within the SCHISM (Semi-implicit Cross-scale Hydroscience Integrated System Model) framework. Some unique features of the TMM are dynamic rates, cross-scale simulations, and incorporation of anthropogenic stressors, which allow it to overcome many limitations that current marsh models possess. To evaluate model performance, the TMM was applied in Carter Creek and Taskinas Creek within the York River system (Virginia, USA). We assessed model outputs against field observations focusing on two main aspects: marsh boundary evolution and distribution of marsh sediments. Marsh change is captured with an accuracy of 81% in Carter Creek and an accuracy of 78% in Taskinas Creek. Different statistical descriptors were used to evaluate the model’s ability to reproduce the distribution of observed marsh sediment fractions. Results in both study areas show a satisfactory agreement between sediment model outputs and field observations. This innovative modeling approach will help close some critical knowledge gaps in the current understanding of the system dynamics and allow better implementation of management actions to preserve these ecosystems and their services.