9-8 Marsh Shoreline Change Analysis to Inform Nature-Based Erosion and Marsh Loss Mitigation in Beaufort County, SC.

Session: Advances in Geologic Mapping, Databases, and Dissemination: Student Posters

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Abstract:

As part of the National Fish and Wildlife Foundation–funded project Building Capacity for Beaufort County’s Resilience with Living Shorelines, this study evaluates long-term estuarine shoreline change across Beaufort County to identify and prioritize locations for nature-based solution (NBS) implementation. Coastal communities in the southeastern United States are becoming increasingly vulnerable to shoreline erosion, habitat loss, and flooding due to sea-level rise, storm impacts, and development pressures, creating an urgent need for spatially explicit decision-support tools to guide resilience investments.

High-resolution EagleView Pictometry aerial imagery (2-ft spatial resolution) from 2004 (2-ft spatial resolution), 2017 (4-inch Resolution), and 2025 (3-inch resolution) was analyzed to quantify shoreline change over a 21-year period. Standard three-band imagery was enhanced to a five-band surrogate dataset by generating pseudo-vegetation indices using raster function templates, enabling improved discrimination between vegetated land and open water. Supervised land–water classification outputs were converted to polygon features, and shoreline position was inferred from the land–water interface. Polygon overlays across time slices were used to identify spatial patterns of erosion and accretion, which were quantified and visualized within a GIS environment to assess relative shoreline vulnerability. All imagery used in the analysis has been resampled to horizontal positional accuracy of approximately 2 ft, and shoreline change results are interpreted within this spatial uncertainty envelope, emphasizing relative patterns and trends rather than precise point-scale shoreline positions.

Results reveal spatially heterogeneous shoreline behavior across the county, with distinct clusters of persistent erosion and localized accretion associated with marsh migration, inlet dynamics, and protected embayments. These patterns provide a defensible basis for prioritizing candidate sites for living shorelines and other NBS strategies. The resulting products are intentionally designed to be visually intuitive, allowing shoreline change trends and priority areas to be readily interpreted by both technical practitioners and non-technical stakeholders. By directly supporting site prioritization, project scoping, and cost-effective NBS deployment, this work aligns with the planning and investment priorities of the South Carolina Office of Resilience, providing an actionable framework for guiding state and local resilience funding decisions.

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