2021 Volume 77 Issue 2 Pages I_799-I_804
On the Zushi coast facing Sagami Bay, longshore sand transport induced by the wave-sheltering effect owing to the Hayama Port breakwater prevails along this coast, resulting in shoreline recession and advance on the north and south sides, respectively. Part of sand transported southward and crossed the permeable jetty is deposited inside the Tagoshi River mouth, causing closure of a river mouth at the river mouth with shoreline recession on the north end of the beach. As a measure against beach erosion, recycle use of sand which was dredged from the Tagoshi River mouth located the southeast end of the pocket beach has been transported to the northwest end. Since there is a gap between the concrete blocks of the jetty, the amount of sand transported to the river mouth is large, resulting in increase in maintenance cost of sand transport. As a measure, the closure of this gap between the concrete blocks is effective for preventing sand deposition.
