Modeling the Impacts of Sand Placement Strategies on Barrier Island Evolution in a Semi-enclosed Bay System: Model Input and Results

The impacts of five proposed restoration alternatives at Little Dauphin Island, Alabama (AL) were assessed using process-based numerical models to simulate annual scale sediment transport and storm-driven morphological change. The five restoration alternatives include a no-action scenario representing a continuous island (R0), a tidal inlet channel realignment (R1), a sand spit (sand motor) nourishment (R2), a beach and dune restoration (R3), and an offshore borrow source (R4). A two-dimensional XBeach model was used to simulate storm-driven beach and dune evolution for each scenario for three historic storms: Hurricane Ivan (2004), Hurricane Katrina (2005) and Hurricane Sally (2020). A two-dimensional Delft3D model was used to simulate sediment transport and resultant bed level morphologic change for each scenario over a 5-year period. The modeled initial and final bed level elevations for each scenario are provided here. For further information regarding input generation and visualization of model outputs, refer to Passeri and others (2025).

Passeri, D.L., Mickey, R.C., Thompson, D.M., Itzkin, M., Godsey, E., Bilskie, M.V., Seymour, A., Poisson, A., Ikeda, J., and Hagen, S.C., 2025 , Modeling the impacts of sand placement strategies on barrier island evolution in a semi-enclosed bay system: Coastal Engineering, v. 197, no. 104697, https://doi.org/10.1016/j.coastaleng.2025.104697.