Interpretation of recovery process and estimation of recovery trend of tsunami-induced salinized groundwater

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06301
• 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: National Agriculture and Food Research Organization
• Principal Investigator: Tsuchihara Takeo 国立研究開発法人農業・食品産業技術総合研究機構, 農村工学研究部門, 上級研究員 (30399365)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 津波 / 地下水 / 塩水化 / 水素・酸素安定同位体比 / 溶存ガス

Outline of Final Research Achievements

Field observation in a tsunami-induced salinized coastal aquifer using multiple environmental tracers (such as major ions, stable isotope ratios of hydrogen and oxygen, and sulfur hexafluoride) revealed the differences in contribution of recharge sources to the aquifer, groundwater residence time, and residual saline groundwater. The results showed that the application of these environmental tracers can provide information to help understand a groundwater recharge process, a classification of recharge sources, and a difference in recovery process from tsunami salinization.

Free Research Field

地下水水文学

Academic Significance and Societal Importance of the Research Achievements

環境トレーサーを指標とした調査により塩水化した地下水の再淡水化への回復状況は同地域内でも一様ではなく，異なる涵養源の寄与度，地下水流動実態によりその回復過程が異なることを示した。ここで用いた指標および調査手法は，津波被災地域での営農再開に向けた地下水利用計画立案の検討時に活用できると考えられる。