| Project/Area Number |
18K05890
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 41030:Rural environmental engineering and planning-related
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| Research Institution | National Agriculture and Food Research Organization |
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Principal Investigator |
Ishida Satoshi 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, 研究領域長 (30414444)
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| Project Period (FY) |
2018-04-01 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2021)
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| Budget Amount *help |
¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000)
Fiscal Year 2020: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2018: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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| Keywords | 二重揚水 / アップコーニング / 地下水 / 塩水化 / 津波 / 東日本大震災 / パッカー / 揚水試験 / 回復 |
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| Outline of Final Research Achievements |
Pumping tests were carried out every three months in 19 monitoring wells in Watari district, from 2018 to 2020 to clarify degree of recovery from groundwater salinization caused by tsunami. Since saltwater was distributed in deep part of aquifer, a packer was installed at boundary between saltwater and freshwater in the pumping tests. Groundwater was pumped from a shallower depth than the packer (test A), and from both shallower and deeper depth than the packer at the same time (test B).
(A) The closer to the coast, the higher the EC of the pumped groundwater. Near the coast, the shallower the packer's depth, the lower the EC of groundwater. When the packer's depth was 5m, the EC of groundwater was less than 200mS / m at all points. These results show that groundwater with low EC can be used by reducing the depth of the well.
(B) The EC of groundwater pumped from two depths at the same time maintained a constant value. These results show that upconing can be suppressed by this method.
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| Academic Significance and Societal Importance of the Research Achievements |
本研究により，津波被災地において塩水化した地下水の回復状況を調査する手法とその結果が示され，新たな学術的知見が得られた。また，塩水化した地下水が残っている地域で，淡水を再利用するための方法が示された。このことは，農業用地下水の安定的な確保や営農計画の策定に向けた有益な情報となることが期待される。
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