2019 Fiscal Year Final Research Report

Re-evaluation of water purification function of the forest with high frequency measurements of water chemistry

Research Project

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Project/Area Number	17H03832
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Research Field	Forest science
Research Institution	Kyoto Prefectural University (2019) Kyoto University (2017-2018)
Principal Investigator	Katsuyama Masanori 京都府立大学, 生命環境科学研究科, 教授 (40425426)
Co-Investigator(Kenkyū-buntansha)	尾坂兼一滋賀県立大学, 環境科学部, 講師 (30455266) 芳賀弘和鳥取大学, 農学部, 准教授 (90432161)
Project Period (FY)	2017-04-01 – 2020-03-31
Keywords	森林の水質浄化機能 / 高時間分解能観測 / 自動観測センサー / 硝酸イオン濃度 / 溶存有機態炭素濃度 / 降雨流出過程
Outline of Final Research Achievements	Long-term observations of stream and groundwater quality were conducted at short intervals of less than 10 minutes. The stream and groundwater observation in a forested area in Shiga prefecture, and streamwater observation in a forested area in Okayama prefecture were carried out. The observation in Shiga prefecture revealed that both nitrate (NO3-) and dissolved organic carbon (DOC) concentrations responded sharply to fluctuations in stream flow, but the flow-concentration relationship was not constant and varied from case to case. However, due to the failure of this device, it was not possible to obtain stable data continuously for a long period of time. In the observation in Okayama prefecture, data were obtained stably except in the winter season when it was closed by snow, but it was found that sediment generated during floods affected the observed values.
Free Research Field	森林水文学
Academic Significance and Societal Importance of the Research Achievements	本研究では水質を短時間間隔で測定可能な自動センサーを用いた。同種の装置適用は欧米では過去10年以上にわたって進んでおり、多くの成果が出ているが、日本国内では本研究が初の適用事例である。そのため、日本に森林流域で同種の装置を適用する上での問題点は何かを整理することが第1歩として重要である。結果として得られた、製品選びから設置・運用上の注意点に至る情報は学術コミュニティにおいて貴重な財産となる。また、この観測から得られた、森林流域における水質変動メカニズムの解明は、今後増加が予想される豪雨災害における森林の役割を評価する上で、社会的意義も大きいものである。