Regenerative Terrain Strategies for Barrier Island Resilience MICP-informed Sedimentation Approach to Louisiana's Chandeleur Islands

Barrier islands shield coastal areas from storms and rising seas but are increasingly vulnerable due to climate-induced impacts. Since 1998, a series of hurricanes and environmental hazards—including major oil spills—have intensified erosion along Louisiana’s coastline, resulting in widespread land loss and the gradual disappearance of vulnerable barrier islands. Current strategies involve engineered interventions such as relocating offshore materials, installing physical barriers to capture sand, introducing native plantings, and building wave-deflecting structures. While these methods aim to rebuild and stabilize islands, they often fail to account for the dynamic coastal processes at play and rely on carbon-intensive practices that may not support long-term ecological resilience. This study proposes the use of regenerative terrain manipulation strategies to actively influence sediment transport and mitigate erosion, with the goal of enhancing the long-term resilience of Chandeleur Island. Grounded in principles of microbially induced calcium carbonate precipitation (MICP), the sedimentation approach draws on bio-stabilization techniques shown to strengthen coastal soils, supporting the island’s capacity to recover and adapt to evolving environmental conditions. This study employs a mixed-methods experimental approach to test the proposed hypothesis. The first phase involves an in-depth analysis of the Chandeleur Islands’ history and the broader geomorphological processes that shape barrier islands. This includes examining recent physical changes—such as erosion patterns and sediment transport—alongside natural site characteristics like soil composition. A localized spatial analysis, conducted using ArcGIS, evaluates parameters such as wave exposure and predicted soil erosion to identify key vulnerabilities. These insights inform the development of regenerative terrain strategies using Docofossor, a Grasshopper-based terrain manipulation tool, to design MICP-guided dune formations. These dune configurations are physically tested through sandbed experiments simulating wave action to measure subaerial sediment deposition and erosion. Image depth mapping is used to analyze volumetric changes. The tests are expanded to a larger site scale using DuneWorm, another Grasshopper tool, to simulate sediment transport under varying wind-induced wave energy conditions. Results indicate that a three-legged terrain manipulation pattern performs consistently across all wind directions, suggesting its potential as an optimal strategy for island restoration. These findings support the potential of MICP-informed dune systems as a low-carbon, regenerative approach to rebuilding barrier islands. By integrating geomorphology, ecology, and computational design, this research offers adaptive and scalable strategies for coastal resilience and climate-responsive restoration.