What-if nature-based storm buffers on mitigating coastal erosion

Area of Science:

• Coastal engineering
• Marine ecology
• Nature-based solutions

Background:

• Intertidal zone ecosystem restoration is gaining traction for coastal erosion mitigation.
• Seagrass meadows offer a nature-based solution to buffer storm impacts.

Purpose of the Study:

• To assess the effectiveness of seagrass meadows in reducing coastal erosion using a modeling framework.
• To determine optimal strategies for planting seagrass for enhanced coastal protection.

Main Methods:

• An integrated model framework combining hydrodynamic and morphodynamic (XBeach) simulations was employed.
• The model was applied to simulate storm impacts and erosion on the coast of Norderney, German Bight.
• What-if scenarios were used to evaluate different seagrass meadow configurations.

Main Results:

• Optimizing seagrass meadow location and size significantly improves erosion mitigation efficiency.
• Maximum meadow size does not always correlate with the greatest erosion reduction; depth and storm intensity are key factors.
• Seagrass density and stem height are critical for achieving substantial erosion reduction (at least 80%).

Conclusions:

• Seagrass transplantation is a viable nature-based solution for coastal erosion control.
• Effective seagrass-based coastal protection requires careful consideration of meadow placement, dimensions, density, and plant characteristics.
• The study provides valuable design insights for implementing seagrass meadows as coastal defenses.