Elucidation of causes of decrease in spring water volume of the Kogane River and measures to restore discharge for conservation of Suizenjinori(Aphanothece sacrum (Sur.) Okada)

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K05882
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 41030:Rural environmental engineering and planning-related
• Research Institution: Kyushu University
• Principal Investigator: Taniguchi Tomoyuki 九州大学, 農学研究院, 助教 (00549123)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: スイゼンジノリ / 湧水 / 希少生物 / 水動態 / 圃場整備 / 太陽光発電

Outline of Final Research Achievements

The Kogane River in Asakura City, Fukuoka Prefecture, is the world's only natural habitat for Suzenjinori(Aphanothece sacrum (Sur.) Okada) under natural conditions. However, in recent years, the discharge(amount of spring water) in the Kogane River has decreased, resulting in a drastic decline in the amount of the Suzenjinori production, and the conservation measures are urgently needed.
In this study, the causes of the decrease in the spring water flow were clarified. Moreover, the introduction of surface drainage from upstream farmland to the Kogane River, winter flooding of surrounding farmland, and reduction of pumping costs using solar power generation were examined as measures to restore the flow, and the effects and problems of each measure were clarified.

Free Research Field

農業農村工学

Academic Significance and Societal Importance of the Research Achievements

これまで明らかにされていなかった黄金川の流量減少の原因を，過去の圃場整備や土地利用の観点から科学的に明らかにした．さらに，水動態，地下水涵養，太陽光発電の活用など，スイゼンジノリの保全に向けた複数の対策を検討した．本研究で実施した研究手法や対策は，同様の課題を抱える他の希少生物の保全にも活用できる．また，本研究をきっかけに，スイゼンジノリに関心をもつ研究者や企業と協働で，スイゼンジノリの保全に向けた活動が始まった．行政との情報交換も始まっており，本研究の成果は今後の保全活動に向けた重要な知見となる．