Application of Mike 21/3 Coupled Model <scp>FM</scp> for Selecting a Suitable Coastal Protection Structure for Hiep Thanh Commune, Tra Vinh Province (Vietnam)†

Coastal erosion in Tra Vinh province and the Mekong Delta region is becoming increasingly severe due to various factors, among which hydrodynamic conditions (tides, waves, river, and sea currents) play a crucial role. This study utilizes the MIKE 21/3 Coupled Model FM to assess the effectiveness of two coastal protection scheme options for the coastal area of Hiep Thanh commune, Tra Vinh: reinforced concrete revetment (Option 1) and hybrid revetment (trees branch fences, geotube bags, and perforated breakwater – Option 2). The results indicate that Option 1 provides better protection for the existing shoreline. However, Option 2 demonstrates superior performance in wave attenuation and beach nourishment, with the ability to reduce wave height approaching the shore by up to 70%. Option 2 also contributes to erosion reduction and shoreline lowering during the Northeast monsoon season (high water levels and strong waves). This study provides a scientific basis for selecting a suitable coastal protection scheme for the Hiep Thanh commune and can serve as a reference for areas with similar natural conditions. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.