2024 Volume 80 Issue 18 Article ID: 24-18012
In the port planning of Hitachi-naka Port, it is determined that the east breakwater of the port is to be extended by 2032 southward for 350 m length relative to the present condition, resulting in the total length from 5,650 m to 6,000 m. After the elongation, the direction of waves incident from the opening between the tip of the east breakwater and Isozaki fishing port breakwater rotates clockwise, resulting in the increase in incident wave angle relative to the direction normal to the shoreline. This enhances the intensity of northward longshore sand transport. Taking these changes into account, beach changes of Ajigaura Beach were predicted using the BG model. It was concluded that the recovery of a sandy beach is possible at Ajigaura Beach when an impermeable breakwater is newly constructed south of the present south breakwater together with the beach nourishment using 30,000 m3 of sand, even if the east breakwater is elongated. Moreover, the removal of the north breakwater is effective to reduce the closedness of Ajigaura Beach.
