Updated on 2021/03/24

写真a

 
TSUBAKI Ryota
 
Organization
Graduate School of Engineering Civil and Environmental Engineering 2 Associate professor
Graduate School
Graduate School of Engineering
Undergraduate School
School of Engineering Architecture
Title
Associate professor
Contact information
メールアドレス

Degree 1

  1. Doctor (Engineering) ( 2006.3   Kobe University ) 

Research Interests 2

  1. High resolution inundation flow simulation and its application to mitigate physical and environmental risks

  2. Advanced field monitoring of fluid flow and sediment transport

Research Areas 2

  1. Social Infrastructure (Civil Engineering, Architecture, Disaster Prevention) / Hydroengineering

  2. Social Infrastructure (Civil Engineering, Architecture, Disaster Prevention) / Disaster prevention engineering

Current Research Project and SDGs 3

  1. Development of river channel morphology control approach

  2. Advanced field monitoring of fluid flow and sediment transport

  3. High resolution inundation flow simulation and its application to mitigate physical and environmental risks

Research History 2

  1. Nagoya University   Department of Civil and Environmental Engineering   Associate professor

    2016.4

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    Country:Japan

  2. Hiroshima University   Assistant Professor

    2012 - 2016.3

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    Country:Japan

Education 1

  1. Kobe University   Graduate School, Division of National Science and Technology

    2003.4 - 2006.3

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    Country: Japan

Professional Memberships 2

  1. IAHR

  2. 土木学会

Committee Memberships 10

  1. 土木学会・河川観測高度化研究小委員会   委員長  

    2020.12   

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    Committee type:Academic society

  2. 土木学会 水工学委員会 河川部会   委員  

    2020.4   

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    Committee type:Academic society

  3. 土木学会・流量観測高度化研究小委員会   委員長  

    2019.6 - 2020.12   

  4. 土木学会・水工学論文集編集小委員会   幹事  

    2019.4 - 2021.3   

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    Committee type:Academic society

  5. 土木学会・水工学論文集編集小委員会   委員  

    2017.10 - 2019.3   

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    Committee type:Academic society

  6. 土木学会・水工学委員会 基礎水理部会   委員  

    2017.6   

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    Committee type:Academic society

  7. 土木学会・水工学委員会 グローカル気候変動適応研究推進小委員会   幹事  

    2016.4   

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    Committee type:Academic society

  8. 第12回 International Association of Hydro environment Engineering Research, Eco Hydraulics 部門 国際シンポジウム 運営委員会   委員  

    2016.2 - 2019.3   

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    Committee type:Academic society

  9. 土木学会・流量観測高度化研究小委員会   委員  

    2011.3 - 2020.3   

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    Committee type:Academic society

  10. 土木学会水工学委員会河川部会   部会員  

    2009.4   

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Awards 1

  1. 土木学会・第61回水工学講演会・ベストディスカッションアワード

    2017.3   土木学会・水工学委員会  

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    Award type:Award from Japanese society, conference, symposium, etc.  Country:Japan

 

Papers 57

  1. Morphological Evolution of bifurcated channel with reopened and narrowed side channel inlets Reviewed

    Zhu, R. and Tsubaki R.

    Japan Society of Civil Engineers   Vol. 76   page: 1225 - 1230   2020.10

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    Authorship:Corresponding author   Language:English   Publishing type:Research paper (scientific journal)  

  2. Multi-camera large-scale particle image velocimetry

    Tsubaki Ryota

    MEASUREMENT SCIENCE AND TECHNOLOGY   Vol. 31 ( 8 )   2020.8

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1088/1361-6501/ab85d5

    Web of Science

  3. 実河川の可視化表面流速分布データを利用した水深分布の推定に関する研究 Reviewed

    椿 涼太,加藤敦貴

    土木学会河川技術論文集   Vol. 26   page: 143-148   2020.6

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    Authorship:Lead author   Language:Japanese  

  4. 河床の大礫に付着したコケの剥離に関する実験的研究 Reviewed

    椿 涼太,飯嶋洋樹,戸田祐嗣,田代喬

    土木学会河川技術論文集   Vol. 26   page: 325-330   2020.6

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  5. 画像を利用した水文観測を実施する際の実務上の課題と対応策 Reviewed

    椿 涼太

    土木学会河川技術論文集   Vol. 25   page: 209-212   2019.6

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    Authorship:Lead author   Language:Japanese  

  6. 砂堆形状の変遷過程における砂粒子の移動と河床近傍流速の特性 Reviewed

    北村 旭,椿 涼太,河原 能久,内田 龍彦

    土木学会論文集B1(水工学)   Vol. 74 ( 5 ) page: I_973 -I_978   2018.11

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  7. 植生流出が河岸侵食に与える影響に関する実験的研究 Reviewed

    尾花まき子,中村俊之,戸田祐嗣,椿 涼太

    土木学会論文集B1(水工学)   Vol. 74 ( 5 ) page: I_1267-I_1272   2018.11

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  8. Influence of deflection angles on flow behaviours in open-channel bends

    Li Bing-dong, Zhang Xin-hua, Tang Han-song, Tsubaki Ryota

    JOURNAL OF MOUNTAIN SCIENCE   Vol. 15 ( 10 ) page: 2292-2306   2018.10

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1007/s11629-018-4848-y

    Web of Science

  9. Integrated Flood Countermeasures in the Upper and Middle Chao Phraya River Basin Reviewed

    Jamrussri, S., Toda, Y. and Tsubaki, R.

    Journal of Applied Water Engineering and Research     2018.7

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1080/23249676.2018.1497559

  10. Spatio-temporal patterns of sediment particle movement on 2D and 3D bedforms

    Tsubaki Ryota, Baranya Sandor, Muste Marian, Toda Yuji

    EXPERIMENTS IN FLUIDS   Vol. 59 ( 6 )   2018.6

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1007/s00348-018-2551-y

    Web of Science

  11. 砂堆を形成した砂粒子の移動の可視化計測 Reviewed

    椿 涼太,Sandor Baranya, Marian Muste, 戸田祐嗣

    土木学会論文集B1(水工学)   Vol. 74 ( 4 ) page: I_1093-I_1098   2018.3

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  12. 洪水氾濫流による鉄道施設被害 Invited

    椿 涼太

    ながれ   Vol. 37 ( 1 ) page: 27-32   2018.2

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    Language:Japanese  

  13. On the Texture Angle Detection Used in Space-Time Image Velocimetry (STIV)

    Tsubaki Ryota

    WATER RESOURCES RESEARCH   Vol. 53 ( 12 ) page: 10908-10914   2017.12

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1002/2017WR021913

    Web of Science

  14. Railway embankment failure due to ballast layer breach caused by inundation flows Reviewed

    Tsubaki, R., Kawahara, Y., and Ueda, Y.

    Natural Hazards   Vol. 87 ( 2 ) page: 717-738   2017.5

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1007/s11069-017-2789-3

  15. 小出水中に礫河川の河床材料に作用する圧力の時間変動の実測 Reviewed

    椿 涼太

    土木学会論文集B1(水工学)   Vol. 73 ( 4 ) page: I-697-I_702   2017.3

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  16. 砂堆上の個別砂粒子の移動計測の試み Reviewed

    北村 旭,河原 能久,椿 涼太

    土木学会論文集B1(水工学)   Vol. 73 ( 4 ) page: I_529-I_534   2017.3

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  17. A new geophone device for understanding environmental impacts caused by gravel bedload during artificial floods Reviewed

    Ryota Tsubaki, Yoshihisa Kawahara, Xin-Hua Zhang, Kentaro Tsuboshita

    A NEW GEOPHONE DEVICE   Vol. 53 ( 2 ) page: 1491   2017.2

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    Publishing type:Research paper (scientific journal)  

    DOI: 10.1002/2016WR019726

  18. Acoustic mapping velocimetry Reviewed

    Muste M, Baranya S, Tsubaki R, Kim D, Ho H, Tsai H, Law D.

    Water Resources Research   Vol. 52 ( 5 ) page: 4132-4150   2016

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    Publishing type:Research paper (scientific journal)  

    DOI: 10.1002/2015WR018354

  19. Development of fragility curves for railway embankment and ballast scour due to overtopping flood flow Reviewed

    Tsubaki Ryota, Bricker Jeremy David, Ichii Koji, Kawahara Yoshihisa

    Natural Hazards and Earth System Sciences   Vol. 16 ( 12 ) page: 2455-2472   2016

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    Publishing type:Research paper (scientific journal)  

    DOI: 10.5194/nhess-16-2455-2016

  20. FLUSHING FLOW IMPACT ON INVASIVE AQUATIC PLANT IN A REACH DOWNSTREAM OF A DAM Reviewed

      Vol. 60   page: Ⅰ_1117-1122   2016

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    CiNii Article

  21. CHARACTERISTICS OF INUNDATION FLOW AND FORESEEN DAMAGE IN MOUNTAINOUS FLOOD PLAINS CAUSED BY FLOODS DUE TO PROBABLE MAXIMUM PRECIPITATION Reviewed

    TSUBAKI Ryota, KAWAHARA Yoshihisa, TSUKAI Makoto

    Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering)   Vol. 72 ( 1 ) page: 11-25   2016

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

     A procedure for estimating flood damage to buildings, roads, and railways located in mountainous flood-plains due to probable maximum precipitation events is proposed. Probable maximum precipitation and consequent flood are estimated using the method proposed by Kadoya and Nagamori, 1979. For case study simulations, two areas, both located in the Chugoku District and damaged by recent large flood events, are selected. The characteristics of inundation flow in two areas under flood conditions caused by probable maximum precipitation are estimated using a two-dimensional flow model with fine-resolution calculation grids. Damage to humans and structures caused by probable maximum flood events is estimated based on the relationship between recorded damage due to recent large floods and inundation flow characteristics estimated using our numerical model. Effective measures to increase resilience in communities in mountainous regions are also discussed.

    CiNii Article

  22. HIGH-RESOLUTION DOWNSCALED SIMULATION OF HEAVY RAINFALL IN HIROSHIMA IN AUGUST 2014 USING WRF Reviewed

      Vol. 60   page: Ⅰ_211-216   2016

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    CiNii Article

  23. STUDY ON MEASUREMENT OF BED-LOAD IN GRAVEL-BED RIVER UTILIZING DIGITAL SOUND RECORDER Reviewed

    TSUBOSHITA Kentaro, TSUBAKI Ryota, KAWAHARA Yoshihisa

    Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering)   Vol. 71 ( 4 ) page: I_823-I_828   2015

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    This paper describes a method of measuring flow rate and size distribution of sediment transported in gravel-bed river during small flood. The device developed is inexpensive, compact and can be installed in the river bed by hand. A steel shell covers the device and impact sound when sediment hits the steel shell is recorded by a digital sound recorder stored in the steel shell. The relationship between sound wave profile and a diameter of the impinged sediment particle was validated based on the result of flume experiment. The proposed method was used to measure processes of sediment transport during a flushing flow released from a dam, then the size distribution and amount of bed-load were successfully analyzed.

    CiNii Article

  24. Effects of trees along floodplain edges on the flow structure in compound meandering channel

    Y. Kawahara, R. Tsubaki, F. S. Nhavotso

    Proceedings of the International Conference on Fluvial Hydraulics, RIVER FLOW 2014     page: 483-489   2014.1

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    Measurements have been carried out to clarify the effects of the tree belts along the edges of roughened floodplains on the flow field. A meandering main channel having 0.87 m width and 0.040 m depth with a wavelength of 3.64 m is located along the center of a straight flume, which is 21.8 m long and 2.2 m wide. Flows in a compound channel with three different vegetation layout are measured at the same flow rate: (i) no tree along the floodplain edges, (ii) trees along the half of the floodplain edges, (iii) trees along all the floodplain edges. Measurement has shown that spiral motions are present in the main channel with/without tree belts and that the regions of high primary velocity is concentrated in the main channel over the depth. The tree belts are found to significantly increase the water level, hence decrease the magnitude of primary velocity over the entire channel while they produce small change in velocity distribution, indicating that the flow pattern in the main channel under high water condition is strongly affected by the geometry of the meandering main channel and not by the tree belts along the floodplain edges. © 2014 Taylor & Francis Group, London.

  25. INUNDATION FLOW IN MOUNTAINOUS VILLAGE IN ASA RIVER BASIN DURING 2010 JULY TORRENTIAL RAINFALL EVENT

    TSUBAKI Ryota, ASAI Koji, NAKAMURA Akihiko, TOMURA Kentaro, KAWAHARA Yoshihisa, NAGANO Hiroyuki

    PROCEEDINGS OF THE JAPANESE CONFERENCE ON HYDRAULICS   Vol. 70 ( 4 ) page: I_1441-I_1446   2014

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    In this paper, an inundation .ow in the Matsugase district, Sanyo-Onoda City, during the 2010 July torrential rainfall event was analyzed. Topographical data of this area were measured by aerial LiDAR survey. The DEM obtained by the LiDAR survey was veri.ed by .eld survey data measured by RTK-GPS. A shock-capturing shallow water .ow model with a .ne calculation grid (two to 5 meters in resolution) was utilized to represent inundation .ow in the inundated area. The calculated water depth was compared with the water records. The characteristics of inundation .ow, especially the e.ect of the embankments in the inundated area, and those relation to local damage were discussed. E.ects of embankment rise and reduction of energy loss due to a bridge were evaluated.

    CiNii Article

  26. NUMERICAL ANALYSIS OF HEAVY RAINFALL IN WESTERN SHIMANE PREFECTURE IN AUGUST, 2013 USING WRF-LETKF

    KITA Masato, KAWAHARA Yoshihisa, TSUBAKI Ryota, USHIYAMA Tomoki

    Journal of applied mechanics   Vol. 70 ( 2 ) page: I_277-I_287   2014

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    With the increase of extreme climate events due to the global climate change, urban areas have been becoming more prone to flooding. This trend highlights the importance of effective schemes to mitigate the damage and loss due to inundation. The advancement of numerical prediction method for heavy rainfall is a key technology for early warning. The objectives of this study are twofold. One is to clarify the applicability of the combination of WRF (Weather and Research Forecasting) model and a data assimilation method LETKF (Local Ensemble Transform Kalman Filter). The other is to discuss the evolution of rainfall system that caused heavy rainfall based on the numerical results. We carried out numerical simulation of heavy rainfall in western Shimane prefecture in August, 2013. Comparison between the calculated results and those measured by a radar-AMeDAS shows that the numerical results fail to reproduce the intensity and the location of the heavy rainfall with small success during the latter half of the rainfall event. It is found that the ensemble mean rainfall provides a slightly better results about the peak value and peak time of rainfall compared to those by the deterministic approach without assimilation, showing the effectiveness of LETKF. The heavy rainfall event over Shimane prefecture is considered to have occurred by the southwest moisture flux converge near the front with the orographic effect of the Chugoku distract.

    CiNii Article

  27. Image analysis and reconstruction of the 2008 Toga River flash flood in an urbanised area

    I. Fujita, Y. Kunita, R. Tsubaki

    Australian Journal of Water Resources   Vol. 16   page: 151-162   2013.7

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    In the afternoon of 28 July 2008, a flash flood occurred in the water-friendly reach of the Toga River in Kobe City, tragically drowning five people that included three children. They were among about 50 people enjoying the river environment. The flash flood was caused by sudden localized torrential rain in urbanized area of the small river basin. The onset of the flash flood was captured by a river monitoring camera as consecutive still images, while the surface flow just after the peak flow was videotaped by a TV cameraman without using a tripod. In order to estimate the peak discharge of the flash flood, the space-time image velocimetry technique developed by the authors was applied to the video images after applying image stabilization. The estimated discharge was used as an input hydraulic parameter of the 2D numerical simulation, with a success of reproducing the transient flow pattern observed by the monitoring camera. In addition, the distribution of hydrodynamic force the people in the river were exposed to was calculated to reveal the difficulty of evacuation in flash flood condition, even when the depth of water is less than knee high. © Institution of Engineers Australia, 2013.

    DOI: 10.7158/W12-011.2013.16.2

  28. The uncertainty of local flow parameters during inundation flow over complex topographies with elevation errors Reviewed

    Tsubaki Ryota, Kawahara Yoshihisa

    JOURNAL OF HYDROLOGY   Vol. 486   page: 71-87   2013.4

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.jhydrol.2013.01.042

    Web of Science

  29. On the Spatial Distribution of Aquatic Plant in Gravel River Reviewed

    Tsubaki Ryota, Kawahara Yoshihisa

    PROCEEDINGS OF THE 35TH IAHR WORLD CONGRESS, VOLS I AND II     page: 2049-2055   2013

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    Language:English  

    Web of Science

  30. Numerical Prediction of Heavy Rainfall Using Weather and Research Forecasting Model Reviewed

    Kita Masato, Kawahara Yoshihisa, Tsubaki Ryota, Ushiyama Tomoki

    PROCEEDINGS OF THE 35TH IAHR WORLD CONGRESS, VOLS III AND IV     page: .   2013

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    Language:English  

    Web of Science

  31. Experimental Study of Turbulent Flows in an Open Channel with Different Vegetation Patches Reviewed

    Matsubara Katsuma, Kawahara Yoshihisa, Yamamoto Takuya, Tsubaki Ryota

    PROCEEDINGS OF THE 35TH IAHR WORLD CONGRESS, VOLS I AND II     page: 5416-5424   2013

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    Language:English  

    Web of Science

  32. WASHU OUT PROSESS OF SUBMERGED PLANT DURING FLUSHING DISCHARGE

    MIZUGUCHI Yusuke, TSUBAKI Ryota, KAWAHARA Yoshihisa, MATUBARA Katsuma

    PROCEEDINGS OF THE JAPANESE CONFERENCE ON HYDRAULICS   Vol. 69 ( 4 ) page: I_1351-I_1356   2013

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    Abnormal growth of submerged plants in rivers not only interferes with fishery and navigation but also blocks sunlight from arriving at river bed materials, leading to the growth failure of attached algae that living creatures there are fed on. It is important for river engineers to clarify how submerged plans can grow and be washed out because they can propagate in such a way that their lobed leaves survive in downstream reaches. This study aims at making clear the conditions how some submerge plant is washed away by the floods. The field surveys were conducted before and after an artificial flood from reservoir to measure the distribution of Egeria densa and to quantify its wash-out rate through cross-sections. These results have revealed the wash-out condition of the submerged plant.

    CiNii Article

  33. ESTIMATION OF DETACHMENT RATIO OF ATTACHED ALGAE DUE TO SEDIMENT COLLISION BY USING NDVI IMAGE ANALYSIS

    ISHIO Shota, TSUBAKI Ryota, KAWAHARA Yoshihisa, NAKADOI Yusuke

    PROCEEDINGS OF THE JAPANESE CONFERENCE ON HYDRAULICS   Vol. 69 ( 4 ) page: I_763-I_768   2013

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    To evaluate the detachment process of attached algae in rivers, a series of flume experiments were carried out. Time-series analysis of NDVI (Normalized Difference Vegetation Index) image of cobbles covered by attached algae was conducted to estimate the change in Chl-a or the decrease in attached algae density. A new method to convert NDVI to Chl-a was developed to measure the attached algae density on cobbles in a nondestructive and continuous way. Quantitative analysis of the detached rate of attached algae has shown that the detachment ratio can be closely correlated with the work done by sediment impinging on the cobbles.

    CiNii Article

  34. Dam-break flows over mobile beds: Experiments and benchmark tests for numerical models

    Sandra Soares-Frazo, Ricardo Canelas, Zhixian Cao, Luis Cea, Hanif M. Chaudhry, Andres Die Moran, Kamal El Kadi, Rui Ferreira, Ignacio Fraga Cadórniga, Noemi Gonzalez-Ramirez, Massimo Greco, Wei Huang, Jasim Imran, Jérme Le Coz, Reza Marsooli, André Paquier, Gareth Pender, Marianeve Pontillo, Jeronimo Puertas, Benoit Spinewine, Catherine Swartenbroekx, Ryota Tsubaki, Catherine Villaret, Weiming Wu, Zhiyuan Yue, Yves Zech

    Journal of Hydraulic Research   Vol. 50   page: 364-375   2012.8

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    In this paper, the results of a benchmark test launched within the framework of the NSF-PIRE project Modelling of Flood Hazards and Geomorphic Impacts of Levee Breach and Dam Failure are presented. Experiments of two-dimensional dam-break flows over a sand bed were conducted at Université catholique de Louvain, Belgium. The water level evolution at eight gauging points was measured as well as the final bed topography. Intense scour occurred close to the failed dam, while significant deposition was observed further downstream. From these experiments, a benchmark was proposed to the scientific community, consisting of blind test simulations, that is, without any prior knowledge of the measurements. Twelve different teams of modellers from eight countries participated in the study. Here, the numerical models used in this test are briefly presented. The results are commented upon, in view of evaluating the modelling capabilities and identifying the challenges that may open pathways for further research. © 2012 Copyright International Association for Hydro-Environment Engineering and Research.

    DOI: 10.1080/00221686.2012.689682

  35. New 3-D flow interpolation method on moving ADCP data

    R. Tsubaki, Y. Kawahara, Y. Muto, I. Fujita

    Water Resources Research   Vol. 48   page: -   2012.5

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    A simple but accurate interpolation procedure for obtaining the three-dimensional distribution of three-component velocity data, from moving acoustic doppler current profiler (ADCP) observation data, is proposed. For understanding actual flow structure within a river with complex bathymetry, the three-dimensional mean velocity field provides a basic picture of the flow. For obtaining the three-dimensional distribution of three-component velocity data, in this work, anisotropic gridding was introduced in order to remove the random component of measured velocity data caused by the turbulence of the flow and measurement error. A continuity correction based on the pressure equation was used to reduce both random and systematic errors. The accuracy of the developed method was evaluated using three-dimensional flow simulation data from a detached-eddy simulation (DES). By using the procedure developed, the complex flow structure surrounding the spur dikes section in the Uji River was successfully visualized and explored. The proposed method shows superiorities in both accuracy and consistency for the interpolated velocity field, as compared to the kriging and inverse-distance weighted (IDW) methods. © 2012. American Geophysical Union.

    DOI: 10.1029/2011WR010867

  36. The application of LS-PIV to a small irregular river for inbank and overbank flows

    B. Gunawan, X. Sun, M. Sterling, K. Shiono, R. Tsubaki, P. Rameshwaran, D. W. Knight, J. H. Chandler, X. Tang, I. Fujita

    Flow Measurement and Instrumentation   Vol. 24   page: 1-12   2012.4

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    This paper examines the feasibility of applying a mobile, large scale particle image velocimetry (LS-PIV) system to a 300m reach of a small river in order to estimate the discharge. Detailed velocity measurements at a number of locations were carried out using an acoustic Doppler current profiler (ADCP) and acoustic Doppler velocimetry (ADV) for inbank, bankfull and overbank flows. The lateral distributions of the velocity index k (i.e., the ratio of the depth-averaged velocity to the surface velocity) were found to be influenced by the secondary currents, channel vegetation and flow conditions. An attempt is made to quantify the relationship between secondary flow and the velocity index. Appropriate conclusions and advice relating to the practical use of a LS-PIV system as applied to a small river are given. © 2012 Elsevier Ltd.

    DOI: 10.1016/j.flowmeasinst.2012.02.001

  37. REFINEMENT OF EVALUATION MODEL FOR ATTACHED-ALGAE REMOVAL CONSIDERING REMOVAL PATTERNS

    NAKADOI Yusuke, TSUBAKI Ryota, KAWAHARA Yoshihisa

    PROCEEDINGS OF THE JAPANESE CONFERENCE ON HYDRAULICS   Vol. 68 ( 4 ) page: I_751-I_756   2012

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    Growth and detachment of the attached-algae in river bed is one of the key factors in ecological system in the river. The detachment process of the algae can be categorized into three types, namely 1 Natural detachment due to aging, 2 Detachment due to flow and bed material load and 3 Detachment caused by rolling of the bed material. To evaluate the detachment processes during flood, we conducted a series of field survey in a site in the Johge River. In the period this survey had been conducted, a flushing discharge and a flood due to typhoon were observed. The chlorophyll-a densities on the bed material before and after floods were measured. Based on the field survey results, the detachment processes of algae are evaluated, and a new model to estimate an amount of detachment during the flood is proposed.

    CiNii Article

  38. Earthen embankment breaching

    Weiming Wu, Mustafa S. Altinakar, Chung R. Song, Mahmoud Al-Riffai, Nathaniel Bergman, Scott F. Bradford, Zhixian Cao, Qin J. Chen, Serban G. Constantinescu, Jennifer G. Duan, D. Michael Gee, Blair Greimann, Greg Hanson, Zhiguo He, Pal Hegedus, Thomas Van Hoestenberghe, David Huddleston, Steven A. Hughes, Jasim Imran, Yafei Jia, Jeffrey D. Jorgeson, René Kahawita, Cassie C. Klumpp, Yong Lai, Eddy J. Langendoen, Shielan Liu, Fekadu Moreda, Mark Morris, Hervé Morvan, Bryan Orendorff, Jay Pak, Patrik Peeters, Seann Reed, Brett F. Sanders, Steve H. Scott, Sandra Soares-Frazao, James Sutherland, Martin J. Teal, Ryota Tsubaki, Tony L. Wahl, David M. Weston, David T. Williams, Yves Zech, Limin Zhang

    Journal of Hydraulic Engineering   Vol. 137   page: 1549-1564   2011.12

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    © ASCE. Embankment breaching processes are very complex and involve mixed-regime free-surface flow with overfalls and hydraulic jumps, pressurized pipe flow, strong vertical and lateral erosion, discrete mass failure, and headcut migration. The failure mode and mechanism are affected by upstream and downstream water conditions, embankment configurations, and soil properties and state. Great progress has been made to investigate embankment breaching processes through laboratory and field experiments and real-world case studies. However, most laboratory experiments were for smallscale homogeneous embankments, only a few outdoor experiments were conducted at large scales (up to several meters in height) and/or were of composite construction, and only limited data sets for historical embankment failures were sufficiently documented. A number of parametric, simplified physically-based, and detailed multidimensional physically-based embankment breach models have been established in the past decades, but prediction with these models involves significant uncertainties. The biggest limitation of the existing breach models is quantifying erosion rates or erodibility of cohesive soils and sediment entrainment under embankment break/breaching flows. It is important to conduct more large-scale laboratory experiments and field case studies to improve existing embankment breach models or develop new ones. These models should also be enhanced by incorporating better physical insights, by using more efficient computational technologies, and integrating them into more robust flood forecasting and risk assessment systems with comprehensive relevant databases

    DOI: 10.1061/(ASCE)HY.1943-7900.0000498

  39. Measurement of the flood discharge of a small-sized river using an existing digital video recording system Reviewed

    Tsubaki Ryota, Fujita Ichiro, Tsutsumi Shiho

    JOURNAL OF HYDRO-ENVIRONMENT RESEARCH   Vol. 5 ( 4 ) page: 313-321   2011.12

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    DOI: 10.1016/j.jher.2010.12.004

    Web of Science

  40. FAILURE MECHANISM OF RAILWAY EMBANKMENT DUE TO INUNDATION FLOW CAUSED BY HEAVY RAINFALL Reviewed

    TSUBAKI Ryota, KAWAHARA Yoshihisa, SAYAMA Takahiro, FUJITA Ichiro

    PROCEEDINGS OF THE JAPANESE CONFERENCE ON HYDRAULICS   Vol. 67 ( 4 ) page: I_919-I_924   2011

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    Railway and road embankments on a flood plain affect the propagation of inundation flow. In inundation simulation, the embankment in the flooded area is treated as the solid wall that inundation flow is able to overflow. However, the embankment involves the potential to be damaged during a severe flood event, and the breakage of the embankments causes not only physical damage but also a reduction of transportation function. In this study, the damage to the embankment of the Kishin line during the flood event in August 2009 is analyzed. The topographic and hydraulic conditions of the embankment failure are discussed.

    CiNii Article

  41. ACCURACY VALIDATION OF AN ESTIMATION METHOD OF DISCHARGE HYDROGRAPH USING AN ARTIFICIAL FLOOD Reviewed

    YOSHITAKE Hiroki, KAWAHARA Yoshihisa, TSUBAKI Ryota, NAKADOI Yusuke

    PROCEEDINGS OF THE JAPANESE CONFERENCE ON HYDRAULICS   Vol. 67 ( 4 ) page: I_1237-I_1242   2011

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    An estimation method of flood discharge hydrograph is developed that couples a 2-D unsteady flow model considering the effect of vegetation toppling and a 2-D model for bed elevation change due to bed load transport. The method is applied to a flush flood from the Haizuka dam in the Jouge River where vegetation became submerged with deformation in large areas. Measurements of water level hydrographs at several points, the discharge with ADCP at a weir and bed elevation change at a point were carried out during the flood. It is shown that the estimated discharge hydrograph gives reasonable agreement with the measured result and that the reliable data of bed elevation is crucial to accurate estimation of discharge hydrograph in a steep slope river.

    CiNii Article

  42. QUANTITATIVE EVALUATION OF THE EFFECT OF FLUSH DISCHARGE TO EXFOLIATE OF ATTACHED ALGAE Reviewed

    NAKADOI Yusuke, TSUBAKI Ryota, KAWAHARA Yoshihisa, YOSHITAKE Hiroki

    PROCEEDINGS OF THE JAPANESE CONFERENCE ON HYDRAULICS   Vol. 67 ( 4 ) page: I_1381-I_1386   2011

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    Field measurement and numerical simulation are carried out for an artificial flush flood in 2010 in the downstream reach of Haizuka dam located at the Jouge River to quantify the effect of flush flood on the exfoliation of attached algae. Measured items are water level, chlorophyll a (Chl-a), SS and attached algae at several locations. The relation between Chl-a attached to riverbed stones and velocity at the same location before the flood and the relation between detached rate of the algae and accumulated bed shear stress during the flood are obtained based on the field observation and 2-D numerical simulation. Based on these relations the total amount of supplied algae to water over the measurement reach during the flood is estimated to around 15.0kg in which the total amount of exfoliated algae is estimated to around 9.4kg.

    CiNii Article

  43. Unstructured grid generation using LiDAR data for urban flood inundation modelling Reviewed

    Tsubaki Ryota, Fujita Ichiro

    HYDROLOGICAL PROCESSES   Vol. 24 ( 11 ) page: 1404-1420   2010.5

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1002/hyp.7608

    Web of Science

  44. AN EXAMINATION OF DRIVING FORCE OF WATER SURFACE OSCCILATION AT OPEN-CHANNEL SIDE CAVITY FLOW Reviewed

    KADOTANI Ken, FUJITA Ichiro, TSUBAKI Ryota

    Doboku Gakkai Ronbunshuu B   Vol. 52   page: 757-762   2008

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    It is well known that a surface oscillation is generated by installing a rectangular side-cavity structure to an open channel flow. The intensity of oscillation increases greatly as the increase of the Froude number. In addition, the type of oscillation changes easily depending on the shape of side-cavity and the width of ratio of the main channel to the depth of side-cavity. In our previous experiments, we categorized the oscillation pattern into four types. In the present study, the space-time correlation relations between the surface elevation and the velocity component at the inlet of the side-cavity is examined by the large eddy simulation that allows the water surface variation. It was found that the type of oscillation is largely divided into two types, i. e. with and without a strong depth-velocity correlation.

    CiNii Article

  45. FLOW STRUCTURE ON GROINS DURING FLOOD EVENT AND MORPHOLOGICAL EVOLUTION OF TOPOGRAPHY Reviewed

    TSUBAKI Ryota, FURUHATA Hisashi, TSUJIMOTO Tetsuro

    Doboku Gakkai Ronbunshuu B   Vol. 52   page: 691-696   2008

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    Morphological evolution of the topography of the reach with groins is investigated using a numerical model solving the two-dimensional shallow water equations in this study. A flood event is represented to discuss the dischargedependent change of the interaction between flow structure and sediment transport. The primary flow is meandering according to alternate or multiple bars formed in the channel during low-water and medium-water periods, and it is found that deposition of the fine sand and silt on vegetated area between groins is affected by the meander of primary flow. During a high-water period, on the contrary, the primary flow follows the large-scale topography of the river so that flow on the flood plain is also straightforward according to the large-scale channel form. This straightforward flow on the flood plain, formed between groins, induces three-dimensional flow structure (longitudinal vortex), develops streak go through the groins longitudinally, and forms the rib-shaped topography on the flood plain. This ribbed bathymetry is highly interacting with sediment transport not only within the flood plain but also between the channel and the flood plain.

    CiNii Article

  46. ANALYSIS OF OPEN-CHANNEL CONFLUENCE FLOW HAVING DIFFERENT STEEP SLOPES IN FIXED BED AND MOVABLE BED Reviewed

    DEGUCHI Takashi, FUJITA Ichiro, TSUBAKI Ryota, OZONO Masashi

    Doboku Gakkai Ronbunshuu B   Vol. 51   page: 823-828   2007

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    In Recent years, flood disasters are frequently taking place where relatively steep slope rivers meet in the mountainous area. The cause of the disasters is mainly due to the sudden rise of water level at a confluence, which sometimes accompanies a hydraulic jump in the upstream region. In this research, a numerical simulation based on the shallow water equations and the unstructured grid system is performed to investigate the effect of the discharge ratio to the flow patterns and the riverbed change at a confluence. In order to simulate a river confluence in the mountains, the main channel slope is set at 1/80 with a tributary channel slope of 1/40. Laboratory experiments are also conducted to provide data with respect to water surface profiles and bed variation. Water surface velocity distributions are obtained by an imaging technique, LSPIV, using a high vision video camera. It is made clear that general flow features calculated by the simulation model agree fairly well with the experiments including the locations of hydraulic jumps and local scour.

    CiNii Article

  47. CORRECTION AND INTERPOLATION OF IRREGULARY MEASURED ADCP DATA AND EXTRACTION OF 3-D FLOW CHARACTER Reviewed

    TSUBAKI Ryota, FUJITA Ichiro, MUTO Yasunori, YOROZUYA Atsuhiro

    Doboku Gakkai Ronbunshuu B   Vol. 51   page: 1063-1068   2007

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    Publishing type:Research paper (scientific journal)  

    The procedure of extraction of three-dimensional distribution of velocity field from ADCP measurement data is presented in this study. Cross-sectional velocity distributions have been generally used to indicate three-dimensional feature of flow. However complex flow fields, generated by combination of a complex bathymetry, curve of the channel and river structure, are difficult to investigate only by using the cross sectional velocity distribution. In this study, anisotropic averaging and interpolation method is introduced to remove random component caused by turbulence of flow and random error of measurement. The continuity correction using pressure equation is also used to reduce both random and system errors. The validity of our procedure is confirmed by using three-dimensional numerical simulation result. Finally, by using our procedure, the complex flow around spur-dikes is explored.

    CiNii Article

  48. STANDARD FOR APPLICATION METHOD OF LSPIV TO SURFACE VIDEO RECORD OF ACTUAL FLOOD FLOW Reviewed

    OKABE Takeshi, FUJITA Ichiro, TSUBAKI Ryota, WAKUDA Atsushi

    Doboku Gakkai Ronbunshuu B   Vol. 51   page: 1087-1092   2007

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    Publishing type:Research paper (scientific journal)  

    Using a surface video record of a large-scale flood in Yoshino River, Shikoku, Japan, some problems related to application method of Large Scale Particle Image Velocimetry (LSPIV) are examined in detail. First, from a hydraulic point of view, a new method is proposed for exclusion of incorrect velocity data and calculation of time-averaged velocity. Second, decision standards are examined with respect to the primary LSPIV model parameters. As a result, it was confirmed that the appropriate time-interval, template size and detection area size for PIV analysis procedure range between 1/3 to 1/2 seconds, between 1.5 to 2 times the maximum size of brightness pattern and about 2 times the estimated displacement distance of templates, respectively.

    CiNii Article

  49. ANALYSIS OF OPEN-CHANNEL FLOW WITH A SIDE CAVITY ZONE BY LES TAKING INTO ACCOUNT OF WATER SURFACE VARIATION Reviewed

    KADOTANI Ken, FUJITA Ichiro, TSUBAKI Ryota, MATSUBARA Takayuki

    Doboku Gakkai Ronbunshuu B   Vol. 51   page: 655-660   2007

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    Open-channel flows with a relatively large-scale side cavity zone exhibits water surface oscillations in spanwise or streamwise directions. Although the side cavity zone is installed for improving the water-friendly environment, such oscillations, once occurred in the actual river in the urban areas, may cause flooding, resulting in a large damage in the residential area. In order to investigate the flow features associated with such surface oscillation, the authors have developed a 3D LES model that utilizes a density function for detecting air-water interface. With the developed model, it becomes possible to simulate water surface oscillation observed in the experiments. In this paper, the flow features related to the water surface oscillation as well as the local flow features along the interface between the main channel and the side cavity zone are investigated for the subcritical flows with relatively large Froude number.

    CiNii Article

  50. WATER SURFACE OSCILLATION ANALYSIS OF SIDE CAVITY FLOW USING SHALLOW-WATER MODEL WITH UNSTRUCTURED GRID Reviewed

    TSUBAKI Ryota, FUJITA Ichiro

    Doboku Gakkai Ronbunshuu B   Vol. 50   page: 763-768   2006

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    Numerical simulation and experimental measurement are used to investigate the resonant instabilities in flow past a side cavity. The shallow water flow equations are solved by using the finite volume method with an unstructured grid system. The flow characteristics of numerical and experimental results are compared and found to be in favorable agreement qualitatively between the results, especially behavior of a long term and large scale oscillation mechanism. The frequencies of oscillation mode analyzed by POD (Proper Orthogonal Decomposition) are compared to theoretical and semi-empirical formulae, from which the feature of the short term oscillation and the long term one are distinguished. The condition which provides an intense long term oscillation are discussed by using experimental and numerical results.

    CiNii Article

  51. FIELD MEASUREMENTS AND INUNDATION ANALYSIS OF THE FLOODED AREA OF THE IZUSHI RIVER IN 2004.10 Reviewed

    OZONO Masashi, TSUBAKI Ryota, FUJITA Ichiro, Kawatani Takeshi

    Doboku Gakkai Ronbunshuu B   Vol. 50   page: 685-690   2006

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    There occurred a levee break of the Izushi River near the district of Torii in Izushi-chou, Hyogo Pref. on Oct. 20, 2004, which is caused by the heavy rainfall induced by Typhoon No. 23 (TOKAGE). In order to perform a high-resolution inundation simulation of this area, detailed topographical data is measured by using a kinematic GPS system. Two dimensional shallow water equation based on the unstructured grid system is used for the simulation. Since the grid size is adjusted so that respective houses can be resolved in the simulation, it became possible to estimate hydrodynamic forces exerted on the houses, which is found to have a close relation to the actual house damages.

    CiNii Article

  52. WATER SURFACE OSCILLATION ANALYSIS OF SIDE CAVITY FLOW USING STEREOSCOPIC IMAGE MEASUREMENT AND POD Reviewed

    FUJITA Ichiro, TSUBAKI Ryota

    Doboku Gakkai Ronbunshuu B   Vol. 49   page: 535-540   2005

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    When a relatively large side cavity zone is installed in an open channel, the influence of separated vortices and recirculation flow generated at the zone is sometimes exerted to the main flow as water surface oscillation. The mechanism of the oscillation is still not clearly understood because of the complexity of the phenomena. In this research, by using a stereoscopic surface measurement system developed by the authors, time-dependent water surface configurations are successfully measured at a sampling rate of 12Hz, from which general features of the surface oscillation is made clear for a wide range of the Froude number. We then applied the proper orthogonal decomposition (POD) method to the measured data and found out that the surface oscillation can be clearly decomposed into a Seiche-like major mode and sub-modes with smaller wavelengths.

    CiNii Article

  53. EXPERIMENTAL STUDY OF FLOW IN CURVED RECTANGULAR OPEN CHANNEL WITH SIDE CONCAVITY Reviewed

    TSUBAKI Ryota, FUJITA Ichiro, NAKANO Atsushi

    Doboku Gakkai Ronbunshuu B   Vol. 48   page: 859-864   2004

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    This study aims to clarify the flow structure in curved rectangular open channel with a side concavity. Surface flow velocity profile is measured using PIV technique and bottom flow direction is obtained by a new method using image analysis of bottom streamlines visualized by dye injection method. In curved channel flow, developing process of secondary flow is examined. The structure of channel flow with side concavity in each side is investigated and their differences are clarified. The results show that water level is lager in the case the side concavity is installed in the outer bank. On the other hand, surface fluctuation is greater in the inner bank case. The aspect ratio of channel width to water depth changed the structure of the flow around side concavity.

    CiNii Article

  54. MEASUREMENTS OF WATER SURFACE VARIATIONS BY USING STEREO VIDEO IMAGES Reviewed

    TSUBAKI Ryota, FUJITA Ichiro

    Doboku Gakkai Ronbunshuu B   Vol. 48   page: 523-528   2004

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    Publishing type:Research paper (scientific journal)  

    This paper presentsa new innovativem ethod for measuringt wo-dimensionawl aterl evel variations.T his method uses a pair of images captured by a stereo arrangement of CCD cameras. With this method it is possible to measure the instantaneous water surface form non-intrusively. At first, we explain the measurement principal and the experimental procedure for obtaining stereo images. Second, we exam measurement accuracy by applying our technique to waves and surface ripples generated by a falling drop, and find that we can resolve waves as small as 1mm. Third, we measure periodic surface fluctuation produced in an asymmetry cavity with a reasonable accuracy. Finally, we describe the problems of this technique and future research plans.

    CiNii Article

  55. VELOCITY MEASUREMENTS AROUND NON-SUBMERGED AND SUBMERGED SPUR DYKES BY MEANS OF LARGE-SCALE PARTICLE IMAGE VELOCIMETRY Reviewed

    FUJITA Ichiro, MUTO Yasunori, SHIMAZU Yoshiro, TSUBAKI Ryota, AYA Shiro

    Doboku Gakkai Ronbunshuu B   Vol. 47   page: 943-948   2003

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    Publishing type:Research paper (scientific journal)  

    Field observations on the surface flow were carried out in a straight reach of the Uji River. Velocity distributions on the water surface were obtained based on the captured video images by means of large-scale particle image velocimetry (LSPIV). Flow structures around spur dykes are studied for both non-submerged and submerged cases.<BR>It is clearly seen that, for both cases, the dykes are working as an additional roughness. Their effect on channel conveyance capacity is estimated in terms of the effective channel width calculated from the velocity distributions. It is also of interest that the maximum velocity filament appears at a different position as the water depth varies in case of the channel with single-side dykes such as studied here. In addition, large-scale boils shedding from the submerged dykes are clearly observed and their origin and advection mechanisms are also evaluated.

    CiNii Article

  56. EVALUATION OF SIDE CONCAVITY STRUCTURE INSTALLED IN URBAN RIVER USING FINITE VOLUME METHOD WITH UNSTRUCTURED GRID SYSTEM Reviewed

    FUJITA Ichiro, TSUBAKI Ryota

    Doboku Gakkai Ronbunshuu B   Vol. 47   page: 523-528   2003

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    Publishing type:Research paper (scientific journal)  

    A new two-dimensional simulation model for urban rivers applicable to complicated sidewall geometry was developed. The proposed model is based on the finite volume method (FVM) with flux differcncing splitting (FDS) under unstructured grid system. Firstly, the performance of the model was evaluated by the comparison with experimental results for a straight open-channel with a long side concavity having an aspect ratio of ten. The calculated results showed fairly good agreements with the experiments, indicating the good performance of the model. Secondly, the model was used to examine the effects of various sidewall geometries on the local water-level increase at the side concavity section. It was shown that water depth variations within the side concavity section can be controlled by a separation wall and the optimum arrangement of the separation wall for the present side concavity shape was proposed.

    CiNii Article

  57. FIELD MEASUREMENT OF SURFACE VELOCITY DISTRIBUTION BY GRADIENT METHOD USING SPATIOTEMPORAL IMAGES Reviewed

    FUJITA Ichiro, TSUBAKI Ryota

    Doboku Gakkai Ronbunshuu B   Vol. 46   page: 821-826   2002

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    Publishing type:Research paper (scientific journal)  

    A new one-dimensional velocity measurement method using image analysis was developed. In this method, image intensity distribution for a line specified in the mean flow direction on a flow video image was cumulated in the temporal direction, thereby creating a spatiotemporal image with a striped pattern indicating the mean velocity on the specified line. The striped pattern is created due to the convection of image intensity conveyed by the mean flow. This method is applicable to river surface images videotaped from a riverbank during flood. Since the images are distorted the spatial resolution in the far field is relatively low; however, the presented method showed a favorable performance in the measurement of flood surface flow of the U River. The result was compared with that by the large-scale particle image velocimetry (LSPIV) and the new method's superiority was verified. Also a method for improving mapping relationship between the CRT coordinates and the physical coordinates was demonstrated.

    CiNii Article

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Books 2

  1. 水理実験解析書2015年度版

    土木学会( Role: Sole author)

    土木学会  2015.2  ( ISBN:978-4-8106-0828

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    Language:Japanese

  2. 身近な水の環境科学 実習・測定編(自然の仕組みを調べるために)

    日本陸水学会東海支部会( Role: Sole author)

    朝倉書店  2014.6  ( ISBN:978-4254180473

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    Language:Japanese

Presentations 37

  1. 河床の大礫に付着したコケの洪水による剥離のモデル化

    椿涼太

    陸水学会東海支部第23回研究発表会  2021.2.13  陸水学会東海支部会

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    Event date: 2021.2

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン  

  2. 川底での圧力変動計測による土砂移動量の算定の試み

    濱口遼馬,椿涼太

    陸水学会東海支部第23回研究発表会  2021.2.13  陸水学会東海支部会

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    Event date: 2021.2

    Language:Japanese   Presentation type:Oral presentation (general)  

    Venue:オンライン  

  3. Simulation of braiding river morphology development accounting flexibility of riparian vegetation, International conference

    Zhu R. and Tsubaki, R.

    22nd Congress of the Asia and Pacific Division of the IAHR 

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    Event date: 2020.9

    Language:English   Presentation type:Oral presentation (general)  

    Country:Japan  

  4. Bedload transport measurement in a Japanese gravel river using synchronized hydrodynamic and hydroacoustic pressure sensing International conference

    Tsubaki, R., Fuentes-Pérez, J. F., Kawamura, S., Tuhtan, J. A., Sumitomo, K.

    Riverflow2020 

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    Event date: 2020.7

    Language:English   Presentation type:Oral presentation (general)  

    Country:Netherlands  

  5. Flood damage assessment and inundation mapping of Helmand River, Afghanistan

    Karimullah, S., Tsubaki, R.

    土木学会中部支部研究発表会 

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    Event date: 2020.3

    Language:English   Presentation type:Oral presentation (general)  

    Venue:愛知県長野市   Country:Japan  

  6. 洪水中の河床付近の水圧変動の計測

    椿涼太

    陸水学会東海支部第22回研究発表会 

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    Event date: 2020.2

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  7. 実洪水流量を画像で算定する方法に関する研究―画像により得られる表面流速の特徴からの水深分布の推定-

    加藤敦貴,椿涼太

    陸水学会東海支部第22回研究発表会 

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    Event date: 2020.2

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  8. Multi-camera Large-scale Particle Image Velocimetry International conference

    Tsubaki, R.

    38th IAHR congress 

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    Event date: 2019.9

    Language:English   Presentation type:Oral presentation (general)  

    Country:Panama  

  9. Aquatic Mosses on Cobble in Riffles and Those Resistance to Disturbances due to High Flow and Sediment Implement International conference

    Tsubaki, R., Miyamoto, M., Toda, Y. and Tashiro, T.

    38th IAHR congress 

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    Event date: 2019.9

    Language:English   Presentation type:Oral presentation (general)  

    Country:Panama  

  10. On-site measurement of flow, turbulence and sediment transport from remote-sensing and distributed sensor approaches Invited International conference

    Ryota Tsubaki

    Seminar on water resource project 

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    Event date: 2019.5

    Language:English   Presentation type:Oral presentation (general)  

    Country:Hungary  

  11. 被災事例に基づいた洪水氾濫による道路盛土法肩洗掘の被害発生条件の検討 International conference

    野村竜矢,椿 涼太

    土木学会中部支部研究発表会 

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    Event date: 2019.3

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  12. 河川河床近傍の多地点・連続モニタリング技術開発の為の基礎的研究 International conference

    椿 涼太,飯嶋洋樹,金田一清香

    土木学会中部支部研究発表会 

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    Event date: 2019.3

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  13. 河床付着苔の出水撹乱に対する応答

    宮本雅也,椿涼太,田代喬,戸田祐嗣

    陸水学会東海支部第21回研究発表会 

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    Event date: 2019.2

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  14. Image analysis for river flow observation International conference

    Ryota Tsubaki

    16th Annual Joint Seminar between Korea and Japan 

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    Event date: 2018.9

    Language:English   Presentation type:Oral presentation (general)  

    Country:Korea, Republic of  

  15. LSPIV app data fusion of velocity and elevation data International conference

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    Event date: 2018.8

    Language:English   Presentation type:Oral presentation (general)  

    Country:Japan  

  16. Measurement of pressure fluctuation on bed cobbles during small floods International conference

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    Event date: 2018.8

    Language:English   Presentation type:Oral presentation (general)  

    Country:Japan  

  17. 洪水プロセスの接触・非接触モニタリング Invited

    椿 涼太

    第6回気象災害におけるAI活用検討会 

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    Event date: 2018.6

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  18. 時空間画像の角度抽出について

    椿 涼太

    第七回 流量観測の高度化に関する勉強会 

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    Event date: 2018.6

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  19. 貯留水の熱的利用可能性に関する研究 その 9放熱実験による自然対流の挙動

    村上季実子,金田一清香,西名大作,河﨑 啓太,北野 博亮,岩田 剛,椿 涼太

    平成29年度日本建築学会中国支部研究会 

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    Event date: 2018.3

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  20. 貯留水の熱的利用可能性に関する研究 その 10 実験値を用いた自然対流モデルの改良

    河﨑 啓太,金田一清香,西名大作,村上季実子,北野 博亮,岩田 剛,椿 涼太

    平成29年度日本建築学会中国支部研究報告集 

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    Event date: 2018.3

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  21. 河川環境の接触・非接触モニタリング

    椿 涼太

    陸水学会東海支部会第20回研究発表会 

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    Event date: 2018.2

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  22. スマートフォンを利用した可視化流量観測アプリケーションの開発-キャリブレーションと地図情報の統合-

    椿 涼太,二瓶泰雄,藤田一郎

    土木学会第72回年次学術講演会 

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    Event date: 2017.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  23. In-situ measurement of gravel transport and near-bed pressure changes in a river during small floods Invited International conference

    Tsubaki, R

    Malaysia-Korea-Japan Mini Symposium on Modeling and Measurement in Hydraulics 

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    Event date: 2017.8

    Language:English   Presentation type:Oral presentation (general)  

    Country:Malaysia  

  24. Field measurements of the absolute pressure distribution acting on bed material Invited International conference

    Tsubaki, R., Toda, Y. and Miyamoto, M.

    37th IAHR congress 

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    Event date: 2017.8

    Language:English   Presentation type:Oral presentation (general)  

    Country:Malaysia  

  25. 砂堆上の粒子計測 Invited

    椿 涼太:

    流砂・河床変動に関する若手勉強会 

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    Event date: 2017.7

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  26. スマートフォンを利用した可視化洪水観測の試みと展望

    椿 涼太

    第六回 流量観測の高度化に関する勉強会 

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    Event date: 2017.7

    Language:Japanese   Presentation type:Public lecture, seminar, tutorial, course, or other speech  

    Country:Japan  

  27. 貯留水の熱的利用可能性に関する研究 その7 CFD解析によるヒートポンプ運用時の放熱過程と熱源温度

    河崎啓太,金田一清香,西名大作,竹原渓吾,椿 涼太

    平成28年度日本建築学会中国支部研究発表会 

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    Event date: 2017.3

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  28. 氾濫原の鉄道盛土の洪水越流破壊の経験的確率関数の構築

    椿 涼太,Bricker Jeremy, 一井康二,河原能久

    土木学会中部支部研究発表会 

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    Event date: 2017.3

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  29. 礫河川の中小洪水時の流れと土砂移動に関する現地計測の試み Invited

    椿 涼太

    第29回東海陸水談話会 

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    Event date: 2016.12

    Language:Japanese   Presentation type:Public lecture, seminar, tutorial, course, or other speech  

    Country:Japan  

  30. モバイルブリッジTMによるライフライン復旧法の一考

    有尾一郎,近広雄希,谷倉 泉,小野秀一,中沢正利,中谷 伸,山田公一,中村繁央,田中義和,椿 涼太,松本慎也,安達光太郎

    第7回インフラ・ライフライン減災対策シンポジウム 

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    Event date: 2016.12

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  31. 礫河川に繁茂するオオカナダモの消長における出水攪乱規模と水温の変化の影響

    椿 涼太,河原能久

    土木学会第71回年次学術講演会 

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    Event date: 2016.9

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  32. スマートフォンを用いた可視化洪水観測の試みと展望

    椿 涼太

    第五回 流量観測の高度化に関する勉強会 

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    Event date: 2016.7

    Language:Japanese   Presentation type:Symposium, workshop panel (public)  

    Country:Japan  

  33. フラッシュ放流にあわせた中礫の瀬への土砂還元の試行

    椿 涼太,坪下健太郎,河原能久

    平成28年度土木学会中国支部研究発表会 

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    Event date: 2016.5

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  34. 二次元・三次元砂堆上の砂粒子の可視化計測

    北村 旭,椿 涼太,河原能久

    平成28年度土木学会中国支部研究発表会 

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    Event date: 2016.5

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  35. 急斜面上の角柱群に作用する流体力の計測

    河津駿二,河原能久,椿 涼太

    平成28年度土木学会中国支部研究発表会 

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    Event date: 2016.5

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  36. 出水規模の違いによるオオカナダモの流出形態と流出量の変化の分析

    小手川勇太,椿 涼太,河原能久

    平成28年度土木学会中国支部研究発表会 

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    Event date: 2016.5

    Language:Japanese   Presentation type:Oral presentation (general)  

    Country:Japan  

  37. Interannual flood impact on aquatic plant cover International conference

    35) Tsubaki, R., Tanaka, S. and Kawahara, Y.

    11th International Symposium on Ecohydraulics 2016 (ISE2016) 

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    Event date: 2016

    Language:English   Presentation type:Oral presentation (general)  

    Country:Australia  

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Works 2

  1. LSPIV app

    Ryota Tsubaki

    2017.1

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    Work type:Software   Location:App store  

  2. SWEapp

    Ryota Tsubaki

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    Work type:Software   Location:App store  

Research Project for Joint Research, Competitive Funding, etc. 12

  1. 一連河道区間と局所的弱点箇所の2重スケール評価による低水護岸・高水敷系侵食被災リスク評価技術の開発

    2020.4 - 2022.3

    河川砂防技術研究開発公募 河川技術分野 

    戸田祐嗣

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    Grant type:Competitive

  2. 小型・多チャンネル絶対圧系を利用した礫河川の河床近傍の乱流現象の実測

    2020.4 - 2022.3

    河川基金 

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    Grant type:Competitive

  3. 画像を利用した洪水流量観測手法に関する研究

    2019.4 - 2021.3

    研究助成 

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    Grant type:Competitive

  4. Multi-camera Large-Scale Particle Image Velocimetry

    2019.4 - 2020.3

    立松財団海外調査研究助成 

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    Grant type:Competitive

  5. 河川洪水可視化計測に関する共同研究

    2019.4 - 2020.3

    国内共同研究 

  6. 河川洪水可視化計測に関する共同研究

    2017.4 - 2019.3

    国内共同研究 

  7. 河床環境のオンライン・リアルタイム計測

    2017.4 - 2018.3

    前田記念財団研究助成 

    椿 涼太

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    Grant type:Competitive

  8. 画像解析法と水理解析の連携による安全・安定的な河川水位・流量計測システムの確立と実用化

    2016.4 - 2018.3

    河川砂防技術研究開発公募 河川技術分野 

    二瓶泰雄

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    Grant type:Competitive

  9. 河床変動過程の可視化計測技術の開発

    2015.4 - 2017.3

    技術開発支援制度 

    椿涼太

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    Grant type:Competitive

  10. Development of a monitoring system for gravel transport during small floods for environmental assessment

    2014.6 - 2016.5

    The Open fund of State Key Laboratory of Hydraulics and Mountain River Engineering (Sichuan University) 

    Ryota Tsubaki

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    Grant type:Competitive

  11. スマートフォンを用いた洪水流量観測システムに関する研究

    2014.4 - 2015.3

    研究開発助成 

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    Grant type:Competitive

  12. 機動的な洪水流の可視化計測システムの開発

    2014.4 - 2015.3

    河川整備基金助成事業 

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    Grant type:Competitive

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KAKENHI (Grants-in-Aid for Scientific Research) 6

  1. 気候変動への段階的適応のための河道地形・植生の中長期動態予測

    Grant number:20H02257  2020.4 - 2025.3

    戸田 祐嗣

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    Authorship:Coinvestigator(s) 

    河川工学分野における気候変動への段階的な適用策を構築するため,本研究では気候変動影響を考慮したうえで河道地形と植生繁茂動態を数十年(10~30年程度)の時間スケールで予測できる技術を開発することを研究目的とする。この目的を達するため,(1)過去から現在に至る河道地形・植生動態の中長期実態分析,(2)既に気候変動の影響が現れつつある近年の大規模出水後の地形・植生動態変化の実態把握,(3)数十年スケールでの河道地形・植生動態予測モデルの開発,および(4)開発されたモデルを用いて将来気候条件へ遷移していく中での段階的な河道地形・植生繁茂を予測する。

  2. Initial recruitment and re-germination mechanism of riparian vegetation onto bare sand bars

    Grant number:17K06575  2017.4 - 2020.3

    Toda Yuji

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    Authorship:Coinvestigator(s) 

    This study aims to clarify the initial recruitment zone of riparian vegetation based on the field investigations. The results show that more seeds accumulated at the shoreline than that at the flat area of the bare bar. It was also found that the seed density at the downstream side of dunes on the bare bar is much higher than that at the upstream side. The hydrochory may be the dominant factor for seed dispersal to shoreline, and wind is the significant seed dispersal approach to the downstream side of dunes on bare bar. The initial recruitment model was proposed with the consideration of inundation frequency, sediment transport and spring flood. The simulation results showed that the initial recruitment zone is along the shoreline with the line shape. The comparison of simulation and field survey results show that the initial recruitment model can well predict the initial recruitment zone.

  3. Development of multi-point monitoring technology and field measurements of sediment movement, near-bed flow, and water temperature in gravel rivers

    Grant number:17K06574  2017.4 - 2020.3

    Tsubaki Ryota

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    Authorship:Principal investigator 

    Grant amount:\4680000 ( Direct Cost: \3600000 、 Indirect Cost:\1080000 )

    A new pressure fluctuation measurement system has been developed for use in riverine environmental surveys. In this study, we carried out a field survey for a flushing discharge event accompanied with channel excavation. The bed-load measurement system developed in a previous study had also used during the survey. The noise in the pressure fluctuation data had recorded during the field survey, and it was likely to be caused by sediment movement. The noise could be removed by using a low-pass filter. A technique for monitoring the flow and water temperature in the vicinity of the riverbed at multiple locations throughout the year had established.

  4. Development of heat supply network using unutilized energy -Application of reservoirs as heat source-

    Grant number:16K06609  2016.4 - 2019.3

    Kindaichi Sayaka

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    Authorship:Coinvestigator(s) 

    We have developed a water source heat pump system using water reservoirs intended for agricultural applications or flood control as a heat source. In this study, we proposed a practical model using TDR (Thermal Distribution Rate), which describes natural convection during heat release from heat pumps, to calculate seasonal variations of heat source temperature. TDR model shows reasonable changes of heat source temperature regardless of whether heat pumps are operated or stopped. Several calculations show high energy saving effects >20% compared to air source heat pumps, indicating that reservoirs are a possible heat source in heat pump systems.

  5. 礫河川の中小出水時の土砂移動の時空間分布計測に基づく藻類の流失モデリング

    2014 - 2015

    科学研究費補助金  若手研究(B)

    椿 涼太

  6. 省電力無線通信網を用いた市街地の浸水モニタリングシステムの開発と基本実証

    2006

    科学研究費補助金 

    椿 涼太

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Industrial property rights 3

  1. 掃流砂観測装置及び掃流砂観測方法

    椿 涼太

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    Applicant:国立大学法人広島大学

    Application no:特願2013-152734  Date applied:2013.7

    Announcement no:特開2015-021935  Date announced:2015.2

    Country of applicant:Domestic  

    J-GLOBAL

  2. 橋梁

    椿 涼太, 中島 卓司, 陸田 秀実, 有尾 一郎

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    Applicant:国立大学法人広島大学

    Application no:特願2012-236673  Date applied:2012.10

    Announcement no:特開2014-084689  Date announced:2014.5

    Patent/Registration no:特許第6502004号 (P6502004)  Date registered:2019.4 

    Country of applicant:Domestic  

    J-GLOBAL

  3. 実河川を対象とした流速観測装置、流速観測方法,および流速観測プログラム

    椿 涼太, 藤田 一郎, 岡部 健士

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    Applicant:国立大学法人神戸大学, 国立大学法人徳島大学

    Application no:特願2006-238738  Date applied:2006.9

    Announcement no:特開2008-058264  Date announced:2008.3

    Country of applicant:Domestic  

    J-GLOBAL

 

Teaching Experience (On-campus) 9

  1. 総合プロジェクトA

    2020

  2. 土木工学のフロンティア

    2020

  3. 環境土木工学実習

    2019

  4. 基礎セミナー

    2016

  5. 開水路水理学

    2016

  6. 研究室セミナー

    2016

  7. 流れ・地形解析学演習

    2016

  8. 水圏力学特論

    2016

  9. 水理学実験

    2016

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