Ryota TSUBAKI / 椿涼太

Dr. (Eng.) / 博士(工学)

Associate Professor, Department of Civil Engineering, Kobe University, Japan

神戸大学大学院市民工学専攻准教授

Publons/Web of Science Link

Google Scholar Link

Researchmap Link

For inquiry to Ryota TSUBAKI, use the inquiry form.

Research interest: 研究テーマ

Understanding the development process of river geomorphology and managing river geomorphology by utilizing natural processes: 河川の地形変化の予測と制御

Keywords: Gravel bed rivers, vegetation, numerical simulation

High-resolution inundation flow simulation and its application to mitigate physical and environmental risks: 高解像度洪水氾濫流解析と、その解析で評価される洪水氾濫流の水理特性に着目した物理的被害や環境への影響の評価と緩和

Keywords: LiDAR, DEM, Finite volume method, Unstructured grid, railway, urban, mountainous

Advanced field monitoring of fluid flow and sediment transport in flooding rivers: 洪水中の河川の流れ・土砂・物質輸送の実測方法の開発と発展

Keywords: Flow visualization, acoustic, pressure, sediment transport, turbulence, gravel bed rivers

Lab members: 研究室メンバー紹介

Ryota TSUBAKI/ 椿涼太

Sefat Karimullah (Research associate, Nagoya University)

Noe KIMURA/木村乃依 (M1)：流砂環境の再生のための自己調節型の土砂供給システムに関する基礎的研究

Maho ISHIHARA/石原真歩 (M1)：中小洪水による網状礫河川の形状変化制御に向けた流速分布計測の現地計測方法の確立

Koki TSURUNAGA/鶴長晃樹 (B4)：過去から現在に至る河道地形および河川生物生息環境の中長期実態分析

Taichi MIYAURA/宮浦太一 (B4)：中山間地と水害

Miku HANIOKA/埴岡光来 (B4)：部分的河道拡幅と通過土砂

Naoya OSHIMA/大島尚也 (B4)：河川の風波

Recent activities

Attended the 22nd Annual Joint Seminar between Korea and Japan at Daegu, South Korea (October 2026)

Dr. Lee at KICT and LOC organized the seminar, and 11 Japanese participants had visited Daegu.

Upper: Geumhogang River, overgrowth of woody riparial vegetation.

Middle: from a submersible bridge. We see blocks on the bridge girder edge, it's helpful for driver (no such structre in Japanese such bridges.)

Bottom: Flood water spillwat inlet at the Yeongcheon Dam.

Upper: WIld sesami hot noodle.

Lower: reproducted Woljeonggyo Bridge. Bridge piers remaining had excavated, analyzed and reported by KICT.

Upper: the Arc, venue for the seminar, managed by K-Water and local goverment.

Middle: group photo.

Lower: Sunrise on the way back.

画像解析勉強会@旭川に参加してきました (2026/10)

午前中は，石狩川の旭橋観測所で流量観測の現場状況などを視察・確認しました．

お昼ご飯は，おそば屋さん．10割白，8割白，8割黒，10割黒から選ぶ本格派．

午後の勉強会では，次世代流量観測と河川画像解析について，過去の経緯や動向などを紹介しました．

旭川の近くの神居古潭．昨年度は工事中で近づけませんでしたが，今回は，近づけました．

留萌のゆるキャラ，KAZUMOちゃん．トウモロコシかとおもったら，数の子で赤ちゃんを背負ってる！

セイコーマートのHot chefでザンギが復活していてビックリ（9月に全国大会で行った時には遭遇しなかった）．カフェオレと一緒にしみじみ味わいました！

Attended the CNU Conference of Advanced Technology (CCAT) 2026 at Kongju National University, Cheonan Campus (October 2026)

Prof. Kim at Kongju National University suggested that I join this conference, and I gave a presentation on our field survey study.

A cup of Paik's Dabang Coffee, a famous coffee originated in Korea . It tastes good.

Rainwater infiltration site on campus; a pilot study by Prof. Lee.

The conference session covered diverse topics. The discussion with participants, led my Prof. Kim, was interactive and interesting.

After the conference, on the way to the airport, visited the Indepencence Museum. The exhibition was very fulfilling.

More recent activities

Study supervision

See the page for the supervision.

Description of selected papers

Image motion analysis of sediment particles migrating on dunes

Tsubaki, R., Baranya, S., Muste, M. and Toda, Y.: Spatio-temporal patterns of sediment particle movement on 2D and 3D bedforms, Experiments in Fluids, Vol. 59, No. 93, 2018. Post-print, View-only-version.

Flood Risk Assessment of the Middle Reach of the Helmand River, Afghanistan

K Sefat, R Tsubaki: Flood Risk Assessment of the Middle Reach of the Helmand River, Afghanistan, Journal of Disaster Research 19 (2), 455-464, 2024. Journal link.

A glacial lake outburst flood risk assessment for the Phochhu river basin, Bhutan

T Wangchuk, R Tsubaki: A glacial lake outburst flood risk assessment for the Phochhu river basin, Bhutan, Natural Hazards and Earth System Sciences 24 (7), 2523-2540, 2024. Journal link.

Effects of vegetation distribution along river transects on the morphology of a gravel bed braided river

R Zhu, R Tsubaki, Y Toda: Effects of vegetation distribution along river transects on the morphology of a gravel bed braided river, Acta Geophysica, 72 (2), 1097-1112, 2024. Journal link.

Impact Assessment of Flushing Flow from a Dam to Invasive Aquatic Plant Egeria densa in a Gravel-bed River

R Tsubaki, Y Kawahara, Y Mizuguchi: Impact Assessment of Flushing Flow from a Dam to Invasive Aquatic Plant Egeria densa in a Gravel-bed River, KSCE Journal of Civil Engineering 28 (3), 1062-1074, 2024. Journal link.

Experiment to clarify the condition of railway embankment scour

Tsubaki, R., Kawahara, Y. and Ueda, K.: Railway embankment failure due to ballast layer breach caused by inundation flows, Natural Hazards, Vol. 87, No. 2, doi: 10.1007/s11069-017-2789-3, 2017, Post-print, Journal link.

Fragility curve for railway embankment scour

Tsubaki, R., Bricker, J.D., Ichii, K. and Kawahara, Y.: Development of fragility curves for railway embankment and ballast scour due to overtopping flow, Natural Hazards and Earth System Sciences, EGU, Vol. 16, 2455-2472, doi:10.5194/nhess-16-2455-2016, Paper.

Sediment budgeting using detailed bathymetry maps: Acoustic mapping velocimetry (AMV)

Muste, M., Baranya, S., Tsubaki, R., Kim, D., Ho, H., Tsai, H. and Law, D.: Acoustic mapping velocimetry, Water Resources Research, Vol. 52, doi: 10.1002/2015WR018354, 2016.5, Journal link, Paper.

Spatial interpolation of river ADCP data

Tsubaki, R., Kawahara, Y., Muto, Y. and Fujita, I.: New 3-D flow interpolation method on moving ADCP data, Water Resources Research, Abstract, Paper, Repository

Development of image based flow measurement method and utilization to open water flow analysis

Multi-camera large-scale particle image velocimetry

Tsubaki, R.: Multi-camera large-scale particle image velocimetry. Measurement Science and Technology, doi: 10.1088/1361-6501/ab85d5, 2020, Post-print, Journal link.

On the Texture Angle Detection Used in Space-Time Image Velocimetry

Tsubaki, R.: On the Texture Angle Detection Used in Space-Time Image Velocimetry (STIV), Water Resources Research, Vol. 53(12), doi: 10.1002/2017WR021913, pp.10908-10914, 2017, Post-print, Journal link.

Smartphone apps for river flow measurement (LSPIV apps for iOS and Android)

Tsubaki, R., Fujita, I., Yu, K. and Muste, M.: Large-scale particle image velocimetry (LSPIV) implementation on smartphone, Proceedings of 36th IAHR congress, ISBN: 978-90-824846-0-1, Paper number 3874 on WEB site, Hague, Netherlands, June 28, 2015. Link

Innovation on river monitoring and its application on eco-hydraulics assessment

Development and refinement of methods for measuring water and sediment flow during floods, and assessment of their impact on river ecosystems (riparian and aquatic plants and attached algae)

Compact geophone

Tsubaki, R., Kawahara, Y., Zhang, X and Tsuboshita, K.: A new geophone device for understanding environmental impacts caused by gravel bedload during artificial floods, Water Resources Research, Vol. 53, doi: 10.1002/2016WR019726, 2017, Journal link, Paper, Post-print.

Flood inundation flow modeling

Railway embankment overtopping

Uncertainty assessment of the calculated result

Tsubaki, R. and Kawahara, Y.: The uncertainty of Local Flow Parameters During Inundation Flow Over Complex Topographies with Elevation Errors, Journal of Hydrology, Vol.486, 2013. Journal link, Repository

Mesh generation using LiDAR data

Tsubaki, R., Fujita, I.: Unstructured grid generation using LiDAR data for urban flood inundation modelling, Hydrological Processes, Vol. 24, No. 11, pp. 1404-1420, 2010, Abstract, Paper, Repository

Investigation of flow in a channel in Japanese garden

Tsubaki, R., Nakayama, Y. and Fujita, I.: The design secret of Kyokusui-no-En's meandering channel, Journal of Visualization, Vol. 11, No. 3, pp. 265-272, 2008.7. Abstract, Repository

Ryota TSUBAKI / 椿 涼太