Japan Geoscience Union Meeting 2016

Presentation information


Symbol A (Atmospheric and Hydrospheric Sciences) » A-HW Hydrology & Water Environment

[A-HW16] Water and material transport and cycles in catchment ecosystems: from headwater to coastal area

Thu. May 26, 2016 3:30 PM - 4:45 PM Poster Hall (International Exhibition Hall HALL6)

Convener:*Seiko Yoshikawa(Narional Institute for Agro-Environmental Sciences), Masahiro Kobayashi(Forestry and Forest Products Research Institute), Noboru Okuda(Research Institute for Humanity and Nature), Shin-ichi Onodera(Graduate School of Integrated and Arts Sciences, Hiroshima University), Kazuhisa Chikita(Department of Earth and Planetary Sciences, Faculty of Science, Hokkaido University), Tomohisa Irino(Faculty of Environmental Earth Science, Hokkaido University), Shinji Nakaya(Department of Water Environment and Civil Engineering, Faculty of Engineering, Shinshu University), Mitsuyo Saito(Graduate School of Environmental and Life Science, Okayama University)

3:30 PM - 4:45 PM

[AHW16-P18] Properties of water quality and groundwater flow in Okayama plain

*Yusuke Tomozawa1, Shin-ichi Onodera1, Mitsuyo Saito2, Koichi Kitaoka4, Kazuhiro Yamaguchi3 (1.Graduate School of Integrated Arts and Sciences Hiroshima University, 2.Graduate School of Environmental and Life Science, Okayama University, 3.Department of Applied Science, Okayama University of Science, 4.Okayama University of Science)

Coastal alluvial plains have typical properties of formation, sedimentation, hydrogeology, and water use etc. For example, groundwater recharge from a main river mainly occurs at the upstream area of the plain. But seawater intrusion occurs at the coastal area in case of over groundwater abstraction with less management. For coastal groundwater managements and sustainability, it is important to understand the vulnerability of them and confirm the risk stage, using tracer methods. Our objective is to confirm the groundwater flow and water quality characteristics of Okayama plain. We analyzed chemical composition and oxygen and hydrogen isotopic ratios of water collected at the observation sites.
Inorganic ion components of the groundwater indicated the transition from a river type to a marine type from the upstream area of the plain to the coastal line. The detail types are from Ca-HCO3 type, Na-HCO3 type, to Na-Cl type. In addition, hydrogen and oxygen isotope at the mid-stream site of the plain show different values from a river and sea water. This means different groundwater flow system with different recharge area.