Please join us for a seminar by Alissa Albrecht on November 13th, 2026 at 1:00PM in Kaufman Hall 136
Dissertation/Thesis Title:
Morphodynamic and Vegetative Modeling of Constructed Salt Marshes at Poplar Island
Abstract:
Constructed salt marshes have grown in popularity as a nature-based solution for coastal habitat
restoration and beneficial use of dredged material. However, predicting the long-term performance of
these marshes remains challenging due to complex interactions between hydrodynamics, sediment
transport, and vegetation growth. Although numerical models exist to simulate marsh hydrodynamics,
many represent vegetation through simplified roughness parameters without accounting for the
feedback between vegetation growth, sediment deposition, and marsh elevation change. The Adaptive
Hydraulics (AdH) model, developed by the U.S. Army Engineer Research and Development Center
(ERDC), includes the SEDLIB-VEG module, which couples vegetation growth and mortality with
hydrodynamics, sediment transport and morphological change.
This study assesses the long-term performance of a constructed tidal marsh and evaluates AdH
SEDLIB-VEG as a tool for morphodynamic and vegetation growth modeling of marshes. A twodimensional numerical model was developed for Cell 1B at the Poplar Island Ecosystem Restoration Project in Chesapeake Bay, Maryland. The model simulates tidal exchange, sediment transport, bed
elevation change, and the growth of Spartina alterniflora and Spartina patens in the low and high
marsh, respectively. Model parameters were developed using construction records, tidal observations,
sediment studies, vegetation sampling, and surface elevation table (SET) measurements. A
morphological acceleration technique was applied to make multi-year simulations computationally
feasible. Four years of marsh development were simulated, and model predictions were compared with
field observations of vegetation biomass and surface elevation change to assess model performance.
The results provide insight into the capabilities and limitations of numerical modeling for constructed
marshes and establish a framework for evaluating how marsh platform elevations, tidal channel
geometry, and sea-level rise may influence future restoration designs.