Coastal Erosion Sedimentation

Coastal erosion sedimentation is the process by which large sediment particles are broken down into smaller grains by the continuous action of waves and coastal currents. These finer sediments are then transported by coastal circulation and gradually redistributed until they reach a new state of equilibrium. The process begins with wave and current erosion along the shoreline, followed by sediment transport offshore and along the coast. As particle size decreases, sediments are carried farther into calmer waters, creating a characteristic distribution from coarse material near the erosion source to finer sediments in low-energy environments.

The impacts of coastal erosion sedimentation include navigation hazards caused by shoaling, shoreline changes, altered sediment grain-size distribution, increased water turbidity, changes in seabed depth, and reduced environmental quality and visitor comfort in coastal tourism areas.

Marine numerical modeling provides an effective tool for analyzing and simulating sediment transport generated by coastal erosion. Modeling scenarios are developed based on the estimated sediment budget released from eroding shorelines, enabling quantitative assessment of sediment pathways, deposition patterns, and long-term coastal evolution.

The modeling framework typically combines Hydrodynamic Modeling with Wave Modeling, including Spectral Wave, Nearshore Spectral Wave, Wave Refraction–Diffraction, and Wave Analysis modules to evaluate wave energy and coastal circulation. Bed Sediment Transport, Suspended Sediment Transport, and Particle Tracking modules simulate sediment movement and grain-size distribution, while the Coastal Morphology module predicts long-term shoreline evolution and erosion patterns.