KAWAI Takayuki

写真a

Affiliation

Graduate School of International Resource Sciences 

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Research Interests 【 display / non-display 】

  • 地下水

  • 水文水資源

  • 自然地理

  • 水文地質

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Graduating School 【 display / non-display 】

  • 　
    -
    1999.03

    Hosei University   Faculty of Literature   Graduated

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Graduate School 【 display / non-display 】

  • 　
    -
    2006.03

    Tottori University  Graduate School, Division of Agricltural Sciences  Doctor's Degree Program  Completed

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Campus Career 【 display / non-display 】

  • 2021.12
    -
    Now

    Akita University   Graduate School of International Resource Sciences   Associate Professor  

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Research Achievements 【 display / non-display 】

    ◆Original paper【 display / non-display 】

  • Sand movement analysis of the Tottori Sand Dunes using aerial photogrammetry by UAVs

    Tadaomi SAITO, Takayuki KAWAI, Yoshiki TAKAHARA, Dai NAGAMATSU, Koji Inosako

    Journal of Arid Land Studies ( 日本沙漠学会 )  34 ( S ) 87 - 91   2024  [Refereed]

    Research paper (journal)  

    <p>The Tottori Sand Dunes, located along Japan’s Sanin Coast, are a UNESCO Global Geopark and a popular tourist attraction with millions of annual visitors. Monitoring of environmental conditions including sand movement is needed for the protection and utilization of the dunes. The objectives of this paper were (i) accuracy evaluation of aerial photogrammetry using three UAVs (Unmanned Aerial Vehicles: Drones) and two types of structure from motion (SfM) software and (ii) sand movement analysis in the dunes using the best results. For each flight, about 1800 vertical photographs (side overlap: 60%, and top-bottom overlap: 80%) were taken at altitudes of approximately 100 m above ground level using three UAVs for a 1500 km<sup>2</sup> area of the dunes. The obtained images were processed using two SfM software, PhotoScan Professional (currently Metashpae: Agisoft) and Pix4Dmapper (Pix4D), for building 3D models. The position data of survey piles in the dunes were used as the GCP (ground control point) setting for image processing and model evaluation. The results revealed that the accuracy of the models was significantly affected by the difference in the SfM software but was not greatly influenced by the difference in UAVs. The models generated from PhotoScan generally curved and had larger errors at the center parts and around the edges of the models (average RMSE=1.74 m), while the models generated from Pix4Dmapper had smaller errors throughout the entire areas (average RMSE=0.38 m). From the comparison of the models obtained from Pix4Dmapper, the characteristics of sand movement such as the movement of the ridge line towards the inland area, were elucidated in the dunes from 2016 to 2018.</p>

    DOI CiNii Research

  • Water level change of Lake Tana, source of the Blue Nile: Prediction using teleconnections with sea surface temperatures

    Yasuda H.

    Journal of Great Lakes Research ( Journal of Great Lakes Research )  48 ( 2 ) 468 - 477   2022.04  [Refereed]

    Research paper (journal)   International Co-author

    Water level change of Lake Tana, the source of the Blue Nile was analyzed. Correlations between the water level change and global sea surface temperature (GSST) were calculated and teleconnections were found. Prediction of water level was performed using a recurrent artificial neural network model. First, the seasonal change of water level was divided into three phases, the rising, recession 1, and recession 2 phases. The water level increased during the rising phase, decreased rapidly during the recession 1 phase, and decreased at a uniform rate during the recession 2 phase. To find teleconnections of the water level change in the rising phase with GSST, correlations between the level change and GSST were calculated. Sea regions on the Pacific Ocean indicated significant correlations with the level change at lag 0–1 month and lag 6–7 months. There was a strongly correlated sea zone over the western Pacific Ocean at time lags of 6–7 months. To predict water level change, SST time series of the correlated zone was applied to a recurrent neural network model. Predictions of changes of the rise of the water level of Lake Tana during the rainy season from teleconnections with SSTs via the neural network model simulated the observed changes well (r = 0.795). Prediction of the changes of Lake Tana's water level with a lead time of 6–7 months can greatly facilitate management of the lake's water resources.

    DOI

  • Teleconnection of rainfall time series in the central Nile Basin with sea surface temperature

    Yasuda H.

    Paddy and Water Environment ( Paddy and Water Environment )  16 ( 4 ) 805 - 821   2018.10  [Refereed]

    Research paper (journal)   International Co-author

    DOI

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    ◆Other【 display / non-display 】

  • Development of a method for identifying well drilling sites using vegetation as an indicator in semi-arid grassland areas

    Birukawa Yuri, Kawai Takayuki, Sakanaka Shinya, Tsuchiya Ryouta, Takatsuki Seiki, Batoyun Tserenpurev, Morinaga Yuki

    Proceedings of the General Meeting of the Association of Japanese Geographers ( The Association of Japanese Geographers )  2024a ( 0 ) 180   2024

    DOI CiNii Research

  • Construction of Virtual Reality Space of the Tottori Sand Dunes using UAVs

    SAITO Tadaomi, KAWAI Takayuki, OKASHITA Kisumi, INOSAKO Koji

    沙漠研究   32 ( S )   2022

    J-GLOBAL

  • Use of UAV Photogrammetry for Monitoring Topographic Changes in the Tottori Sand Dunes, Japan

    LIU Jiaqi, KIMURA Reiji, WU Jing, KAWAI Takayuki

    日本砂丘学会誌   69 ( 1 )   2022

    J-GLOBAL

  • Investigation of groundwater distribution using a ground penetrating radar in the Tottori sand dunes

    齊藤忠臣, 河合隆行, 西本貴之, 猪迫耕二, 安田裕, 塩崎一郎

    応用水文   33 ( 33 ) 51 - 60   2021.03

    J-GLOBAL

  • Land susceptibility to water and wind erosion risks in the East Africa region

    Fenta A. A, Tsunekawa A, Haregeweyn N, Poesen J, Tsubo M, Borrelli P, Panagos P, Vanmaercke M, Broeckx J, Yasuda H, Kawai T, Kurosaki Y

    Science of The Total Environment   703   135016   2020.02

    DOI

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Grant-in-Aid for Scientific Research 【 display / non-display 】

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Presentations 【 display / non-display 】

  • Influence of polacrylamede application on structure stability of Ethiopian soils

    Fujimaki H, Kawai T, Mamedov A.L

    10th International congress on the Soil resources and environment conservation  2018.10  -  2018.10 

  • Aerial photogrammetry and three-dimensional modeling of the Tottori sand dune using UAV

    Saito, T, Kawai, T, Inosako, K, Yasuda, H

    Desert Technology 13 International Conference  2018.03  -  2018.03 

  • Estimation of hydrogeological structure combining groundwater-aeration-sound, ground-penetrating- radar and resistivity tomography in semi-arid area

    Takayuki Kawai, Motoyuki Sato, Yasuyuki Tada, Ryota Tsuchiya, Yuki Morinaga, Masato Shinoda, Seiichirou Kuroda, Hiroshi Yasuda

    Desert Technology 13 International Conference  2018.03  -  2018.03 

  • NMR and GPR sounding to characterize groundwater aquifer in sand dunes area

    Chisato Konishi, Kunio Aoike, Takayuki Kawai, Seiichiro Kuroda

    Symposium on the Application of Geophysics to Engineering and Environmental Problems 2017  2017.03  -  2017.03 

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