Ocean long wave monitoring system and hazard map related to the occurrence of secondary undulation in the western coast of Southern Kyushu

2021 Fiscal Year Final Research Report

• Project/Area Number: 18H01684
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 25030:Disaster prevention engineering-related
• Research Institution: Kagoshima University
• Principal Investigator: Yamashiro Toru 鹿児島大学, 理工学域工学系, 教授 (20158174)
• Co-Investigator(Kenkyū-buntansha): 加古 真一郎 鹿児島大学, 理工学域工学系, 准教授 (60709624) ; 齋田 倫範 鹿児島大学, 理工学域工学系, 准教授 (80432863)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 副振動 / 海洋長波 / 自動監視システム / 小島漁港 / 枕崎漁港 / ハザードマップ / 上甑島浦内湾

Outline of Final Research Achievements

In this study, it was suggested that the occurrence of large secondary undulation at Oshima fishing port and Makurazaki fishing port in Kagoshima prefecture can be predicted with almost 50% accuracy by monitoring ocean long waves in Meshima Island, Nagasaki prefecture. We were also able to complete a prototype model that can monitor the secondary undulation and long ocean waves in real time.
It was possible to identify the flooded areas of houses and roads when a large secondary undulation occurrs in Urauchi Bay of Kamikoshiki Island at the time of high tide. Furthermore, we clarified the evacuation place of small boats when the secondary undulation occurrs and the suitable place for the installation of the tuna farming cage because the influence of the seiche is small.

Free Research Field

海洋物理学

Academic Significance and Societal Importance of the Research Achievements

副振動は周期数分から数10分の海水面の上下動であり、南九州西岸域では冬から春先にかけて頻繁に発生する。そして、波高が2ｍを超えるような大きな副振動は、発生時期によっては家屋浸水や道路冠水、小型船舶の転覆、養殖生簀破損と養殖魚の逃げ出し等の被害を及ぼす。本研究成果として小島漁港と枕崎漁港における大きな副振動の発生予測の実現性を明らかにできたことや、上甑島浦内湾の副振動ハザードマップに資するデータを作成できたことは、漁港利用者の船舶、積み荷等の財産、マグロ養殖の生産活動を副振動災害から防ぎ、安心・安全な地域づくりに貢献するという点で社会的な意義が深いと言える。