AMITA Kazuhiro

写真a

Affiliation

Graduate School of Engineering Science  Department of Systems Design Engineering  Civil and Environmental Engineering Course 

Research Interests 【 display / non-display

  • 水資源・地表環境学

Graduating School 【 display / non-display

  • 1991.04
    -
    1995.03

    Kochi University   Faculty of Science   Graduated

Graduate School 【 display / non-display

  •  
    -
    2003.03

    Kyoto University  Graduate School, Division of Natural Science  Doctor's Course  Completed

Campus Career 【 display / non-display

  • 2018.04
    -
    Now

    Akita University   Graduate School of Engineering Science   Department of Systems Design Engineering   Civil and Environmental Engineering Course   Assistant Professor  

  • 2016.04
    -
    2018.03

    Akita University   Graduate School of Engineering Science   Research Center for Engineering Science   Assistant Professor  

  • 2014.04
    -
    2016.03

    Akita University   Graduate School of Engineering and Resource Science   Research Center for Engineering Science   Assistant Professor  

Research Areas 【 display / non-display

  • Natural Science / Atmospheric and hydrospheric sciences  / 水資源・地表環境学

  • Environmental Science/Agriculture Science / Environmental impact assessment

 

Research Achievements 【 display / non-display

    ◆Other【 display / non-display

  • Prototype geochemical towing observation system for detection of coastal seafloor discharge of volcanic fluids and its evaluation of performance at volcanic CO<sub>2</sub> upwelling area

    OHSAWA Shinji, AMITA Kazuhiro, MISHIMA Taketoshi, SAITO Kei, MASAMOTO Futo, TAKAHASHI Hiroshi, MORIKAWA Noritoshi

    Journal of Japanese Association of Hydrological Sciences ( THE JAPANESE ASSOCIATION OF HYDOROLOGICAL SCIENCES )  52 ( 3 ) 107 - 121   2022.12

    <p>A prototype “Geochemical Towing Observation System" was developed to detect the presence of volcanic fluids discharging from the coastal seafloor in shallow waters from the sea. We confirmed the stable operation of the observation system and evaluated its ability to detect volcanic fluid discharge in one of the coastal waters of Himeshima Island (Oita Prefecture, Japan), where volcanic CO<sub>2</sub> gas has been discharged from the seafloor. In the observed sea area, as the concentration of dissolved inorganic carbon (DIC) in seawater increases, its δ<sup>13</sup>C value changes toward the estimated δ<sup>13</sup>C of volcanic CO<sub>2</sub>, so we believe that the observation system has successfully captured the seafloor discharge of volcanic fluids. In addition to DIC, a significant change in redox potential (ORP/Eh) also appeared, which can be explained by the detection of H<sub>2</sub>S dissolved in seawater contained in seafloor gases. Combined measurements of <sup>222</sup>Rn, salinity corresponding to electric conductivity, and water temperature, which have been effective in detecting submarine groundwater and hot spring water discharges from the seafloor in the Beppu Hot Springs coastal area in the back of Beppu Bay, showed no expected changes. This may indicate that submarine groundwater discharge from the seafloor along the coast of Himeshima Island is not significant and that gas discharge is the main cause.</p>

    DOI CiNii Research

  • STUDY ON IMPROVEMENT OF TAMAGAWA ACIDIC WATER USING FLY ASH GRANUTRALIZER

    SAITO Noritoshi, KAGAYA Fumito, IKEUCHI Takao, SASAKI Asuka, MINAMIDA Yu, AMITA Kazuhiro

    Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research) ( Japan Society of Civil Engineers )  78 ( 5 ) I_233 - I_238   2022

    <p> The Tamagawa acidic water originates from the Tamagawa hot springs in eastern Akita Prefecture. Currently, the pH of Lake Tazawa has increased from 4.6 to about 5.8 due to the operation of a neutralization treatment facility. However, it has not recovered to 6.8, and the water environment and ecosystem have not yet recovered. In this study, a neutralizer was prepared using fly ash to improve Tamagawa acidic water and to expand the use of coal ash. Neutralization experiments were conducted to evaluate the effectiveness of the neutralizer by analyzing pH changes, the neutralizer, and treated water. The results showed that the neutralizer did not disintegrate or leach heavy metal ions in the weakly acidic range, suggesting that the neutralizer could be used stably.</p>

    DOI CiNii Research

  • A study on water balance and water quality improvement in Lake Tazawa

    OYAGI Hideo, CHIKITA Kazuhisa, AMITA Kazuhiro, Fujii Tomoyasu

    Proceedings of the General Meeting of the Association of Japanese Geographers ( The Association of Japanese Geographers )  2020 ( 0 )   2020

    <p>A study on water balance and water quality improvement in Lake Tazawa</p>

    DOI

  • Chemical and Isotopic Compositions of Fumarolic Gases from Yakedake Volcano, Japan

    SAITO Takeshi, SAWAMURA Shun, TAMURA Rina, SEKI Susumu, AMITA Kazuhiro, MISHIMA Taketoshi, OHSAWA Shinji

    BULLETIN OF THE VOLCANOLOGICAL SOCIETY OF JAPAN ( The Volcanological Society of Japan )  64 ( 1 ) 1 - 9   2019

    <p>Since the latest phreatic eruption in 1962-1963, Yakedake volcano has remained dormant, but fumarolic activity around the summit area has continued steadily during the past hundred years. Temperature, chemical, and isotopic compositions of fumarolic gases were ascertained for 2013-2017. Discharge temperatures of the most active fumarole were 113-123°C: much lower temperatures than those during the active period. Lower concentrations of HCl and H<sub>2</sub> and a lower SO<sub>2</sub>/H<sub>2</sub>S ratio coincide with this relative quiescence of the present Yakedake volcano. The apparent equilibrium temperatures estimated from the sulfur reactions were about 250-280°C, which decreased by about 200°Cshortly after the latest eruption and which were lower than the critical temperature of water, suggesting the formation of a volcanic hydrothermal system beneath the summit region. The isotopic compositions of water (D,<sup>18</sup>O) show that the fumarolic fluids were probably formed by mixing of the magmatic fluids and local meteoric water. The contribution of magmatic fluid to the sampled fumarolic fluids was estimated as about 80-90%, which is higher than the values obtained shortly after the latest eruption. The estimated volcanic hydrothermal system under the volcano is possibly less influenced by local meteoric water, in spite of the low discharge temperature and low concentrations of gas species derived from high-temperature volcanic gas.</p>

    DOI

  • Chemical and isotopic compositions of fumarolic gases from Yakedake Volcano, Japan

    Sawamura S., Saito T., Amita K., Mishima T., Ohsawa S.

    PROGRAMME AND ABSTRACTS THE VOLCANOLOGICAL SOCIETY OF JAPAN ( The Volcanological Society of Japan )  2018 ( 0 ) 243 - 243   2018

    DOI

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