Louisiana Coastal Protection and Restoration Authority

Barrier Island Topographic State: Indicators of Resistance vs Resilience

Characterizing the barrier island geomorphic state: Indicators of resistance and resilience

Barrier islands are highly dynamic features with strong connections between the geomorphic state and response to natural processes. Research has shown that geomorphic state, which can be characterized using elevation data and habitat coverage, is linked to a barrier island’s resistance, the island’s short-term response to storms, and resilience, the long-term ability of the barrier island to adapt to sea-level rise. The ability to determine current conditions and predict short- and long-term responses to storms or sea level rise leads to more successful barrier island restoration.

The Challenge

The LA TIG Monitoring and Adaptive Management (MAM) Strategy has identified a need for barrier island creation, restoration, and maintenance (resilient/maintained over time) with the goal of reducing land and habitat loss as a high-level objective under the Wetland, Coastal, and Nearshore Habitats (WCNH) Restoration Type. An associated fundamental objective is to support natural processes of barrier island evolution (e.g., overwash building the back-barrier platform and longshore sediment transport and connectivity between islands) through barrier island restoration projects.

To develop a Specific, Measurable, Achievable, Relevant, appropriate Timeline (SMART) objective, the LA TIG has identified that a Monitoring and Adaptive Management effort is needed to develop and document an approach for assessing and characterizing restored barrier island response to natural processes like overwash or sea level rise.

The Approach

This project will address this information gap while working closely with other ongoing barrier island activities to support integration into planning and restoration, such as the Louisiana Coastal Protection and Restoration Authority’s (CPRA) Barrier Island Comprehensive Monitoring Program (BICM) and Barrier Island System Management Program (BISM). The Water Institute team, along USGS and other partners, will work to outline the resistance and resilience of Louisiana barrier islands based on a literature review and analysis of available data. Supporting data used will include habitat maps, elevation, and sediment grain size. The work will also include stakeholder engagement and coordination throughout the project and documentation of findings in a report.