Development of non-traditional isotope proxies for groundwater hydrological study

• Project/Area Number: 17K00527
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental dynamic analysis
• Research Institution: Kwansei Gakuin University
• Principal Investigator: Tanimizu Masaharu 関西学院大学, 理工学部, 教授 (20373459)
• Co-Investigator(Kenkyū-buntansha): 細野 高啓 熊本大学, 大学院先端科学研究部(理), 准教授 (30367065) ; 若木 重行 国立研究開発法人海洋研究開発機構, 超先鋭研究開発部門(高知コア研究所), 技術研究員 (50548188)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2017: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
• Keywords: 地下水 / 同位体 / 質量分析 / 微量元素 / ICP / 阿蘇山 / 金属元素

Outline of Final Research Achievements

The flow velocity and direction of groundwater have been estimated mainly from hydraulic models, but the isotopic ratios of elements are useful to constrain the parameters independently. In this study, 7Li/6Li and 234U/238U isotope ratios dissolved in groundwater were analyzed to use as new isotopic proxies. Their spacial and temporal changes and trends in concentration and isotope ratio of groundwater in the Kumamoto area showed the usefulness of the isotopic proxies to detect small injection of sea water component or hydrothermal fluid, and groundwater mixing process, respectively.

Academic Significance and Societal Importance of the Research Achievements

地下水は、涵養から流出まで数年から数千年の時間がかかるため、汚染物質が一度混入すると、その除去には膨大な費用と時間が必要となる。熊本市域地下水の例では、上昇傾向にあった硝酸性窒素の濃度は、さまざまな努力により近年減少傾向に向かっているが、その混入起源物質や混入域の特定には完全には至っていない。このような地下水中に混入した人為起源物質の移行を把握し、さらに元素の地下水中での挙動を正しく把握するために、本研究で確立した溶存微量元素の同位体指標による地下水流動の解析は、有用であると考えられる。

Research Products

• [Journal Article] Changes of groundwater flow systems after the 2016 Mw 7.0 Kumamoto earthquake deduced by stable isotopic and CFC-12 compositions of natural springs (2020)
  • Author(s): Ide Kiyoshi、Hosono Takahiro、Kagabu Makoto、Fukamizu Keisuke、Tokunaga Takahiro、Shimada Jun
  • Journal Title: Journal of Hydrology Volume: 583 Pages: 124551-124551
  • DOI: 10.1016/j.jhydrol.2020.124551
  • Peer Reviewed
• [Journal Article] Recovery of lost nexus synergy via payment for environmental services in Kumamoto, Japan (2019)
  • Author(s): Taniguchi, M.、Burnett, K.、Shimada, J.、Hosono, T.、Wada, C.A.、Ide, K.
  • Journal Title: Frontiers in Environmental Science Volume: 7 Pages: 28-28
  • DOI: 10.3389/fenvs.2019.00028
  • Peer Reviewed / Open Access
• [Journal Article] Sequential chemical separation of Sr, Nd and Pb from geological samples using multi-step extraction column chromatography (2018)
  • Author(s): 若木重行、川合達也、永石一弥、石川剛志
  • Journal Title: JAMSTEC Report of Research and Development Volume: 27 Issue: 0 Pages: 1-12
  • DOI: 10.5918/jamstecr.27.1
  • NAID: 130007506144
  • ISSN: 1880-1153, 2186-358X
  • Year and Date: 2018-09-01
  • Peer Reviewed / Open Access
• [Journal Article] A Rapid and Precise Determination of Boron Isotope Ratio in Water and Carbonate Samples by Multiple Collector ICP-MS (2018)
  • Author(s): Tanimizu, M.、Nagaishi, K.、Ishikawa, T.
  • Journal Title: Analytical Sciences Volume: 34 Issue: 6 Pages: 667-674
  • DOI: 10.2116/analsci.18SBP05
  • NAID: 130007395544
  • ISSN: 0910-6340, 1348-2246
  • Year and Date: 2018-06-10
  • Peer Reviewed / Open Access
• [Journal Article] On the use of coprostanol to identify source of nitrate pollution in groundwater (2017)
  • Author(s): Nakagawa Kei、Amano Hiroki、Takao Yuji、Hosono Takahiro、Berndtsson Ronny
  • Journal Title: Journal of Hydrology Volume: 550 Pages: 663-668
  • DOI: 10.1016/j.jhydrol.2017.05.038
  • NAID: 120006987495
  • Peer Reviewed / Int'l Joint Research
• [Presentation] Coseismic hydroenvironmental changes in response to 2016 Mw 7.0 Kumamoto crustal earthquake, southern Japan: insights from multidisciplinary approaches (2019)
  • Author(s): Hosono, T., Manga, M., Wang, C.-Y. and Working Group of Japanese Association for Groundwater Hydrology
  • Organizer: AGU Fall Meeting 2019
  • Int'l Joint Research / Invited
• [Presentation] Distribution and formation of highly saline water in the northwest plain of Aso caldera, south Japan (2019)
  • Author(s): Okamura, K., Hosono, T., Romero-Mujalli, G., Amann, T., Louvat, P., Hartmann, J.
  • Organizer: Goldschmidt Conference 2019
  • Int'l Joint Research
• [Presentation] 海水Ba安定同位体組成の高精度分析法の開発 (2019)
  • Author(s): 若木重行、手塚勇輝、宮崎隆、堀川恵司
  • Organizer: 2019年度日本地球化学会年会
• [Presentation] Trace of anthropogenic nitrate in groundwater by isotopic proxies in Kumamoto area (2019)
  • Author(s): Sugimoto, N.、Sakiyama, M.、Hosono, T.、Tanimizu, M.
  • Organizer: European Winter Conference on Plasma Spectrochemistry 2019
  • Int'l Joint Research
• [Presentation] B-Li isotope systematic of groundwater for water flow proxy (2018)
  • Author(s): Sugimoto, N.、Hosono, T.、Tanimizu, M.
  • Organizer: Resources for Future Generations 2018
  • Int'l Joint Research
• [Presentation] Deciphering downward movement of nitrate through volcanic unsaturated formation using high composition δ15N and δ18O tracers (2018)
  • Author(s): Boateng, D.、Hosono, T.、Okumura, A.、Sakiur Rahman, A.T.M.、Shimada J.
  • Organizer: 45th IAH Congress
  • Int'l Joint Research
• [Presentation] Fully Coupled Surface and Subsurface Flow Simulation with Model Validation Using Stable Isotopes and Tracer of Kumamoto Region in Japan (2018)
  • Author(s): Sakiur Rahman, A.T.M.、Hosono, T.、Tawara, Y.、Boateng, D.、Shimada, J.
  • Organizer: 45th IAH Congress
  • Int'l Joint Research
• [Presentation] δ11B-δ7Li 同位体指標を用いた地下水の起源推定と熊本地震の影響評価 (2018)
  • Author(s): 杉本直人、先山正祐、細野高啓、谷水雅治
  • Organizer: 2018年度日本地球化学会年会
• [Presentation] 微量元素濃度組成と金属元素同位体比からみた熊本地域地下水の地域的特徴と熊本地震による影響評価 (2018)
  • Author(s): Sugimoto, N.、Tanimizu, M.、Hosono, T.
  • Organizer: 日本地球惑星科学連合2018年大会
• [Presentation] 地下温度の繰返し測定による熊本地域の地下水流動変化の検討－2017・2018年測定値と過去データの比較 (2018)
  • Author(s): 宮越昭暢、谷口真人、井手淨、奥村梓、利部慎、細野高啓、嶋田純
  • Organizer: 日本地球惑星科学連合2018年大会
• [Presentation] Origin of groundwater in Kumamoto city estimated from multipe stable isotope proxies (B, Li, O H) (2017)
  • Author(s): Sugimoto N.、Hosono T.、Tanimizu M.
  • Organizer: Asia-Pacific Winter Conference on Plasma Spectrochemistry
  • Int'l Joint Research
• [Presentation] 微量元素B,Liからみた熊本市地下水の起源解析 (2017)
  • Author(s): 杉本直人、細野高啓、谷水雅治
  • Organizer: 日本分析化学会66回年会
• [Presentation] 阿蘇山西麓域における同位体指標B,Liを用いた地下水の起源推定 (2017)
  • Author(s): 杉本直人、細野高啓、谷水雅治
  • Organizer: 2017年度日本質量分析学会同位体比部会
• [Presentation] 環境試料の高精度ホウ素同位体比測定に関する分析条件の最適化 (2017)
  • Author(s): 谷水雅治
  • Organizer: 日本分析化学会66回年会
• [Presentation] Behaviors of nitrate in unsaturated zone in groundwater recharge area in Kumamoto, southern Japan (2017)
  • Author(s): Okumura A.、Hosono T.、Shimada J.
  • Organizer: 44th IAH Congress Groundwater Heritage and Sustainability
  • Int'l Joint Research
• [Presentation] Nitrate behaviors and its transportation time scale in unsaturated zone under farmlands with different fertilization log in Kumamoto region (2017)
  • Author(s): Okumura A.、Hosono T.、Shimada J.
  • Organizer: European Geosciences Union General Assembly 2017
  • Int'l Joint Research