Performance of a Marsh and Sill Shoreline Stabilization Treatment Under Sea Level Rise in Little Lagoon, Gulf Shores, Alabama
Date of Award
Civil, Coastal, and Environmental Engineering
Bret M. Webb, Ph.D., P.E., D.C.E
Little Lagoon is a shallow body of water located in Gulf Shores, Alabama, and an erosion analysis has exhibited that some areas of the southwestern shoreline have been eroding since 1992. A living shoreline project was proposed to mitigate this erosion by creating a staggered system of rip-rap sills with plantings and backfilling. This research focuses on comparing a "with" and "without" project condition using XBeach in a ID, transect based mode to simulate several storm conditions including sea level rise effects based on different scenarios that are expected in 2050. The effectiveness of the living shoreline designs as compared to the existing profile is examined by analyzing profile elevation changes, gross and net cross-shore sediment transport, shoreline position, and average wave height behind the planted vegetation as a proxy for wave energy reduction in terms of submergence. Results showed that the average wave height was reduced and there was a positive effect on shoreline position with the presence of marsh and sill. The sediment transport and shoreline position data did not determine that this project would be worth it for the stakeholders to invest in this project. Future studies using a validated model would provide better results and provide practitioners with a useful application for designing and implementing living shorelines.
Carpenter, Kelsey B., "Performance of a Marsh and Sill Shoreline Stabilization Treatment Under Sea Level Rise in Little Lagoon, Gulf Shores, Alabama" (2022). Theses and Dissertations. 122.