研究者詳細 - 吉田　圭介

論文 - 吉田　圭介

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UAVを活用した河川巡視時のペットボトル検出モデルにおける画像生成AIの応用査読

下江大地, 潘是均, 吉田圭介, 西山哲, 小島崇

土木学会論文集 81 ( 16 ) n/a - n/a 2025年2月

河川カメラ，物体検出AI及び大規模マルチモーダルモデルによる人の河川利用調査の検討査読

山田悠生, 吉田圭介, 潘是均, 小島崇

土木学会論文集 81 ( 16 ) n/a - n/a 2025年2月

Interchangeability of Cross-Platform Orthophotographic and LiDAR Data in DeepLabV3+-Based Land Cover Classification Method 査読

Shijun Pan, Keisuke Yoshida, Satoshi Nishiyama, Takashi Kojima, Yutaro Hashimoto

Land 14 ( 2 ) 217 - 217 2025年1月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：MDPI AG

Riverine environmental information includes important data to collect, and the data collection still requires personnel’s field surveys. These on-site tasks still face significant limitations (i.e., hard or danger to entry). In recent years, as one of the efficient approaches for data collection, air-vehicle-based Light Detection and Ranging technologies have already been applied in global environmental research, i.e., land cover classification (LCC) or environmental monitoring. For this study, the authors specifically focused on seven types of LCC (i.e., bamboo, tree, grass, bare ground, water, road, and clutter) that can be parameterized for flood simulation. A validated airborne LiDAR bathymetry system (ALB) and a UAV-borne green LiDAR System (GLS) were applied in this study for cross-platform analysis of LCC. Furthermore, LiDAR data were visualized using high-contrast color scales to improve the accuracy of land cover classification methods through image fusion techniques. If high-resolution aerial imagery is available, then it must be downscaled to match the resolution of low-resolution point clouds. Cross-platform data interchangeability was assessed by comparing the interchangeability, which measures the absolute difference in overall accuracy (OA) or macro-F1 by comparing the cross-platform interchangeability. It is noteworthy that relying solely on aerial photographs is inadequate for achieving precise labeling, particularly under limited sunlight conditions that can lead to misclassification. In such cases, LiDAR plays a crucial role in facilitating target recognition. All the approaches (i.e., low-resolution digital imagery, LiDAR-derived imagery and image fusion) present results of over 0.65 OA and of around 0.6 macro-F1. The authors found that the vegetation (bamboo, tree, grass) and road species have comparatively better performance compared with clutter and bare ground species. Given the stated conditions, differences in the species derived from different years (ALB from year 2017 and GLS from year 2020) are the main reason. Because the identification of clutter species includes all the items except for the relative species in this research, RGB-based features of the clutter species cannot be substituted easily because of the 3-year gap compared with other species. Derived from on-site reconstruction, the bare ground species also has a further color change between ALB and GLS that leads to decreased interchangeability. In the case of individual species, without considering seasons and platforms, image fusion can classify bamboo and trees with higher F1 scores compared to low-resolution digital imagery and LiDAR-derived imagery, which has especially proved the cross-platform interchangeability in the high vegetation types. In recent years, high-resolution photography (UAV), high-precision LiDAR measurement (ALB, GLS), and satellite imagery have been used. LiDAR measurement equipment is expensive, and measurement opportunities are limited. Based on this, it would be desirable if ALB and GLS could be continuously classified by Artificial Intelligence, and in this study, the authors investigated such data interchangeability. A unique and crucial aspect of this study is exploring the interchangeability of land cover classification models across different LiDAR platforms.

DOI： 10.3390/land14020217

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Trials of Night-Time 4K-Camera-based Human Action Recognition in Riverine Environments with Multimodal and Object Detection Technologies 査読

Shijun PAN, Keisuke YOSHIDA, Yuki YAMADA, Takashi KOJIMA

Intelligence, Informatics and Infrastructure 5 ( 1 ) 89 - 97 2024年11月

Generating 3D Models for UAV-Based Detection of Riparian PET Plastic Bottle Waste: Integrating Local Social Media and InstantMesh 査読

Shijun PAN, Keisuke YOSHIDA, Daichi SHIMOE, Takashi KOJIMA, Satoshi NISHIYAMA

Drones 8 ( 9 ) 471 2024年9月

Assessment of spawning habitat suitability for Amphidromous Ayu (Plecoglossus altivelis) in tidal Asahi River sections in Japan: Implications for conservation and restoration 査読

Keisuke Yoshida, Hiroshi Yajima, Md. Touhidul Islam, Shijun Pan

River Research and Applications 40 ( 8 ) 1497 - 1511 2024年6月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Wiley

Abstract

The Amphidromous Ayu (Plecoglossus altivelis), vital for Japan's riverine commercial fisheries, is experiencing population decline due to habitat degradation. In response, Japan is implementing restoration efforts by releasing juvenile fish and cultivating spawning habitats. This study, focusing on the Asahi River's Heidan area, evaluates Ayu spawning habitat suitability, especially in tidal zones, and its conservation implications. Through field surveys and numerical analysis, the research identifies optimal conditions for spawning amid dwindling numbers. Observations from the 2020 peak spawning season showed that water temperatures below 20°C are conducive to spawning, with the best sites producing up to 48,817 eggs/m². Gravel sizes between 0.85 and 53.0 mm were identified as crucial for effective spawning. Notably, artificial spawning grounds established in 2019 showed no spawning activity, likely due to saline intrusion from tides. Using the three‐dimensional hydrodynamic‐aquatic ecosystem numerical model, the study assesses flow, substrate, and water quality's impact on spawning, corroborated by sensor data. A key finding is the negative correlation between salinity and egg density in tidal sections of the Asahi River. Furthermore, an artificial intelligence (AI)‐based YOLOv5 model, trained on underwater images, effectively detected Ayu aggregations, demonstrating an F1‐score of 0.757 in differentiating Ayu from other coexisting fish species in the same aquatic environment. This AI approach provides a nonintrusive method for monitoring Ayu populations and habitat preferences. The research underlines that successful spawning habitats require minimal saline intrusion, with optimal salinity and flow conditions. These insights are critical for spawning ground development, emphasizing the management of tidal effects and riverbed conditions to bolster Ayu populations and preserve aquatic ecosystems.

DOI： 10.1002/rra.4329

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Monitoring Human Activities in Riverine Space using 4K Camera Images with YOLOv8 and LLaVA: A Case Study from Ichinoarate in the Asahi River 査読

Shijun PAN, Keisuke YOSHIDA, Yuki YAMADA, Takashi KOJIMA

Intelligence, Informatics and Infrastructure 5 89 - 97 2024年5月

Comprehensive Analysis of On-Site Riparian Waste Pollution: A Case Study on the Hyakken River Basin 査読

Shijun PAN, Keisuke YOSHIDA, Takashi KOJIMA

Intelligence, Informatics and Infrastructure 5 98 - 103 2024年5月

航空レーザ計測と洪水解析による植生抗力の３次元分布推定と竹林倒伏・木本流失の再現計算査読

古谷崚, 吉田圭介, 岡田拓巳, 梶川勇樹, 西山哲

土木学会論文集 80 ( 16 ) 23-16161 2024年

ランダムフォレストを用いた多波長励起蛍光光度計による植物プランクトンの組成分類査読

矢島啓, 藤井陽, 管原庄吾, 吉田圭介

土木学会論文集 80 ( 16 ) 23-16032 2024年

ノリ養殖漁場でのクロダイの食害把握に向けた水中画像の深層学習と教師データ基準の検討査読

吉田圭介, 潘是均, 横山貴洋, 山下泰司, 上田勇輝, 杉野博之, 小島崇

土木学会論文集 80 ( 16 ) 23-16150 2024年

Mutual validation of remote hydraulic estimates and flow model simulations using UAV-borne LiDAR and deep learning-based imaging techniques 査読

Md Touhidul Islam, Keisuke Yoshida, Satoshi Nishiyama, Koichi Sakai

Results in Engineering 20 101415 - 101415 2023年12月

Detection and Segmentation of Riparian Asphalt Paved Cracks Using Drone and Computer Vision Algorithms 査読

Shijun PAN, Keisuke YOSHIDA, Satoshi NISHIYAMA

Intelligence, Informatics and Infrastructure 4 ( 2 ) 35 - 49 2023年12月

Application of the Prompt Engineering-assisted Generative AI for the Drone-based Riparian Waste Detection 査読

Shijun PAN, Keisuke YOSHIDA, Takashi KOJIMA

Intelligence, Informatics and Infrastructure 4 ( 2 ) 50 - 59 2023年12月

Three-dimensional numerical modelling of floods in river corridor with complex vegetation quantified using airborne LiDAR imagery 査読

Keisuke Yoshida, Yuki Kajikawa, Satoshi Nishiyama, Md. Touhidul Islam, Shin Adachi, Koichi Sakai

Journal of Hydraulic Research 61 ( 1 ) 88 - 108 2023年1月

Promises and uncertainties in remotely sensed riverine hydro‐environmental attributes: Field testing of novel approaches to unmanned aerial vehicle‐borne lidar and imaging velocimetry 査読

Md. Touhidul Islam, Keisuke Yoshida, Satoshi Nishiyama, Koichi Sakai, Shin Adachi, Shijun Pan

River Research and Applications 38 ( 10 ) 1757 - 1774 2022年12月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Wiley

Recent advancements in remotely sensed techniques have markedly expanded data acquisition potential in riverine studies, but the techniques' applicability must be validated and improved because of uncertainties associated with diverse field conditions. This study is the first experimental evidence of using a newly designed unmanned aerial vehicle (UAV)-borne green lidar system (GLS) and deep learning-automated space–time image velocimetry (STIV) for remote investigation of hydraulic and vegetation quantities of the gravel-bed Asahi River in Okayama Prefecture, Japan. In addition to identifying bed deformation in waters shallower than 2 m, the GLS point clouds characterized the submerged infrastructure with block detailing patterns, thereby identifying positional displacement and severely damaged parts. This paper also presents a noncontact method of estimating incremental river discharge. Compared to benchmarked flow model estimates, remotely sensed discharges for three transects covering shallower, deeper, and partially submerged woody vegetation areas were overestimated by 1–11%, with 4% underestimation for another cross-section. The STIV analysis also showed complicated flow patterns that were reasonably confirmed by flow vectors from depth-averaged modeling. Ultimately, depth-averaged flow model estimates validated hydraulic parameters derived remotely from GLS and STIV, and vice versa. In addition to approximating vegetation growth rates, the study using GLS attributes accurately identified riparian vegetation types as herbaceous (70%), woody (86%), and bamboo groves (65%). Finally, our findings provide insight into the management of shallow clear-flowing vegetated rivers and remote sensing of streamflow to validate hydrodynamic-numerical methods.

DOI： 10.1002/rra.4042

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その他リンク： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/rra.4042

水中カメラの画像と深層学習による魚道を遡上する稚アユの検出に関する検討査読

潘是均, 古谷崚, 吉田圭介, 山下泰司, 小島崇, 白神義章

土木学会論文B1(水工学) 78 ( 2 ) I_127 - I_132 2022年11月

The application of drone-assisted deep learning technology in riverbank garbage detection 査読

Shijun PAN, Keisuke YOSHIDA, Afia S. BONEY, Satoshi NISHIYAMA

Journal of JSCE, B1 78 ( 2 ) I_133 - I_138 2022年11月

堤防越水場に設置した裏法面被覆工の不陸が流体力特性へ及ぼす影響に関する研究査読

飯干富広, 佐々木海音, 安達森, 忰熊公子, 吉田圭介

土木学会論文B1(水工学) 78 ( 2 ) I_655 - I_660 2022年11月

旭川感潮域におけるアユ産卵場面積の拡大を目的とした砂州の横断掘削とその効果の検証査読

吉田圭介, 足立真綾, 矢島啓, 山下泰司, 安達森, 藤井陽

土木学会論文B1(水工学) 78 ( 2 ) I_1111 - I_1116 2022年11月

担当区分：筆頭著者,　責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：公益社団法人土木学会

旭川感潮域の兵団地区においてアユの産卵場面積の拡大を目的に，自然産卵場周辺の砂州の一部を掘削し，平常の流量条件で新たに人工産卵場を造成した．本研究はこれに関連して現地観測と数値計算を行い，造成の成否に関わる水理環境の適性を検討した．また，造成に伴う既存の自然産卵場環境への影響の有無を調べた．その結果，産卵適地は常時，塩分上昇のない区域であり，河床粒度と産卵時間帯の水深，流速が既往研究での適性値内であるとの既往研究の知見が再検証された．また，造成箇所の産卵数密度は流況よりも粒径の適性に依存する可能性が示唆された．さらに，高解像度の平面2次元計算の結果から，本造成は既存の自然産卵場の水理環境をあまり変化させておらず，造成当初の目的である産卵場面積の増大に寄与したことが明らかになった．

DOI： 10.2208/jscejhe.78.2_i_1111

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旭川中原橋周辺の河道形状及び植生分布の違いが更正係数に与える影響に関する数値的検討査読

安達森, 梶川勇樹, 吉田圭介, 西山哲

土木学会論文B1(水工学) 78 ( 2 ) I_1153 - I_1158 2022年11月

Drone-LiDAR-assisted Image Fusion methodology for Deep Learning-based Land Cover Classification 査読

Shijun PAN, Keisuke YOSHIDA, Takashi KOJIMA, Satoshi NISHIYAMA

Intelligence, Informatics and Infrastructure 3 ( 3 ) 15 - 25 2022年11月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Japan Society of Civil Engineers

This study uses an unmanned aircraft mounted green Light Detection and Ranging (LiDAR) system to verify the learnability associated with deep learning regarding land cover classification (i.e., evaluated by the average and the absolute difference value of label-based F1, overall accuracy or Macro F1 under the premise of cross-seasonal mutual-prediction). Image fusion method in this study mainly attempts to superimpose the visualized LiDAR data with the aerial photographs to provide new features. LiDAR data are visualized using high contrast color scale (default), average high contrast color scale (same color, different split points as default), and high contrast gray color scale (different color, same split points as default). The reason of setting these methods is to compare the impact of split points and point-associated color in the color scale on learnability of cross-seasonal data. It is worth noting, however from the view of the results, that relying solely on aerial photographs is not sufficient, comparing with image fusion method, especially when training and predicting using cross-seasonal data. From the comparison of the label-based F1, this study has proved the necessary impact of LiDAR on vegetation label-based land cover classification.

DOI： 10.11532/jsceiii.3.3_15

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YoloV5 analysis for juvenile ayu detection in underwater images of fishway 査読

Shijun Pan, Ryo Furutani, Keisuke Yoshida

Proc. of the 2022 Int. Symp. on Ecohydraulics 2022年10月

Using airborne lidar bathymetry-aided transfer learning method in riverine land cover classification 査読

Shijun Pan, Keisuke Yoshida, Takashi Kojima

Proc. of the 2022 Int. Symp. on Ecohydraulics 2022年10月

Developing 3-D numerical flood flow model for vegetated rivers: A case study for lower Asahi River flooding in Japan 査読

Md. Touhidul Islam, Keisuke Yoshida, Yuki Kajikawa, Satoshi Nishiyama

Proc. of 39th IAHR World Congress 2022年6月

Novel UAV-borne green LiDAR versus traditional airborne LiDAR: A case study to characterize hydraulic and riparian vegetation attributes 査読

Md. Touhidul Islam, Keisuke Yoshida, Satoshi Nishiyama, Koichi Sakai

Proc. of 39th IAHR World Congress 2022年6月

Airborne LiDAR-assisted deep learning methodology for riparian land cover classification using aerial photographs and its application for flood modelling 査読

Keisuke Yoshida, Shijun Pan, Junichi Taniguchi, Satoshi Nishiyama, Takashi Kojima, Md. Touhidul Islam

Journal of Hydroinformatics 24 ( 1 ) 179 - 201 2022年1月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IWA Publishing

<title>Abstract</title>
In response to challenges in land cover classification (LCC), many researchers have experimented recently with classification methods based on artificial intelligence techniques. For LCC mapping of the vegetated Asahi River in Japan, the current study uses deep learning (DL)-based DeepLabV3+ module for image segmentation of aerial photographs. We modified the existing model by concatenating data on its resultant output port to access the airborne laser bathymetry (ALB) dataset, including voxel-based laser points and vegetation height (i.e. digital surface model data minus digital terrain model data). Findings revealed that the modified approach improved the accuracy of LCC greatly compared to our earlier unsupervised ALB-based method, with 25 and 35% improvement, respectively, in overall accuracy and the macro F1-score for November 2017 dataset (no–leaf condition). Finally, by estimating flow-resistance parameters in flood modelling using LCC mapping-derived data, we conclude that the upgraded DL methodology produces better fit between numerically analyzed and observed peak water levels.

DOI： 10.2166/hydro.2022.134

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Characterizing vegetated rivers using novel unmanned aerial vehicle‐borne topo‐bathymetric green lidar: Seasonal applications and challenges 査読

Md. Touhidul Islam, Keisuke Yoshida, Satoshi Nishiyama, Koichi Sakai, Tomoyuki Tsuda

River Research and Applications 38 ( 1 ) 44 - 58 2022年1月

UAVレーザ点群と航空写真を併用した深層学習による河道の地被分類法の検討査読

野村碧都, 吉田圭介, 谷口純一

土木学会論文B1(水工学) 77 ( 2 ) I_913 - I_918 2021年12月

旭川の感潮域におけるアユの好適な産卵場の検討査読

足立真綾, 吉田圭介, 矢島啓, 山下泰司

土木学会論文B1(水工学) 77 ( 2 ) I_1429 - I_1434 2021年12月

Flood risk assessment in vegetated lower Asahi River of Okayama Prefecture in Japan using airborne topo-bathymetric LiDAR and depth-averaged flow model 査読

Keisuke Yoshida, Kimihisa nagata, Shiro maeno, Koji mano, Satoshi nishiyama, Md. Touhidul Islam

Journal of Hydro-environment Research 39 39 - 59 2021年10月

担当区分：筆頭著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Elsevier BV

This paper describes application of airborne LiDAR bathymetry (ALB) with near-infrared and green pulsed lasers for gathering distributed vegetation conditions and topo-bathymetric data for rivers. For the lower Asahi River of Okayama Prefecture in Japan, the ALB data validity was verified using field observation data. This study also examined the applicability of ALB data for numerical simulations of the lower Asahi River flooding in early July 2018 in Japan, comparing simulated and observed data. Results demonstrated that the methodology for this study works well for parameterization of distributed vegetation on a reach scale. This study also applied numerical tests to investigate the effects of vegetation establishment on flood control plans for the lower Asahi River using parameters validated for flood flow simulations. Results demonstrate that the predicted water level markedly exceeds the high water level because of thick vegetation presently established along few-kilometerlong upstream sections of the targeted river reach. Therefore, we conclude that the present findings can support cost-effective management tasks for vegetated rivers.

DOI： 10.1016/j.jher.2021.06.005

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平成30 年7月豪雨時の旭川分流堰周辺の植生分布を考慮した3次元洪水流解析査読

吉田圭介,梶川勇樹,永田貴美久,西山哲,間野耕司,堺浩一,Md. Touhidul ISLAM,児子真也

土木学会論文集B1(水工学) 76 ( 2 ) I_985 - I_990 2020年12月

Model-induced comparative study of ALB and UAV-borne green LiDAR systems on vegetated lower Asahi river assessment in Japan 査読

Md. Touhidul ISLAM, Keisuke YOSHIDA, Koichi SAKAI, Satoshi NISHIYAMA, Tomoyuki TSUDA, Kimishisa NAGATA and Shiro MAENO

土木学会論文集B1(水工学) 76 ( 2 ) I_529 - I_534 2020年12月

ALB 点群データを援用した河川航空写真の深層学習による地被分類法の検討査読

吉田圭介,谷口純一,潘是均,小島崇,永田貴美久,渡邊明英

土木学会論文集B1(水工学) 76 ( 2 ) I_1003 - I_1008 2020年12月

担当区分：筆頭著者,　責任著者記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：公益社団法人土木学会

河道の地被分類は河川の治水や水環境の研究や実務において重要な基礎資料である．近年では豪雨による河川災害が危惧され，特に，地先単位の洪水疎通能力の評価において河積や，河道内の植生の高さおよび密生度が必要となり，例えば航空レーザー測深(ALB)データの更なる利用が期待される．本研究では岡山県旭川下流の国管理の約4.5kmの区間を対象に，ALB計測時に撮影される航空写真を活用し，ALB点群データから得られる植生高とレーザー点数を組み合わせることで新たな深層学習による地被分類方法を開発した．解析の結果，航空写真だけよりもALB点群データを併用することで，竹林・樹木と草本の分類性能が向上した．しかし，時期の異なるデータセットを相互に学習や推論に用いると，落葉などの影響で樹木と草本の分類性能が低下することが分かった．

DOI： 10.2208/jscejhe.76.2_i_1003

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Verification of STIV analysis of flood discharge at Nakano observatory in the Ota River by flow analysis using ALB data 査読

K. Yoshida, S. Nigo, S. Maeno, K. Mano, M. Nakano

Proc. 22nd IAHR-APD Congress 2020年9月

Flood simulation model coupled with woody vegetation wash-out in the lower Asahi River 査読

K. Nagata, K. Yoshida, S. Maeno, S. Nigo, MD. T. Islam

Proc. 22nd IAHR-APD Congress 2020年9月

Estimation of distributed flow resistance in vegetated rivers using airborne topo-bathymetric LiDAR and its application to risk management tasks for Asahi River flooding 査読

Keisuke Yoshida, Shiro Maeno, Shuhei Ogawa, Koji Mano and Shinya Nigo

Journal of Flood Risk Management 13 ( 1 ) e12584 2020年3月

植生高分布と限界掃流力を考慮した植生流出を伴う洪水流解析モデルの検討査読

吉田圭介,前野詩朗,永田貴美久,児子真也,赤穗良輔

土木学会論文集B1(水工学) 75 ( 4 ) I_325 - I_330 2019年12月

2018 年7 月西日本豪雨時の岡山県での降雨特性と旭川水系での洪水被害の調査解析査読

吉田圭介,前野詩朗,工藤亮治,近森秀高,赤穗良輔,小川修平,永田貴美久

土木学会論文集B1(水工学) 75 ( 1 ) 172 - 183 2019年12月

2018 年豪雨による倉敷市真備地区の被災状況と包括型氾濫解析モデルによる氾濫シナリオの検討査読

前野詩朗,赤穗良輔,二瓶泰雄,赤松良久,吉田圭介

土木学会論文集B1(水工学) 75 ( 1 ) 387 - 402 2019年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：公益社団法人土木学会

<p> 2018年7月豪雨災害により，倉敷市真備町を流下する小田川及びその支流の末政川，高馬川，真谷川の複数箇所で堤防が決壊し，真備町では1200haの地域が浸水し，多くの方が犠牲となった．本研究では，現地調査により浸水状況を明らかにした．また，河道の洪水流と決壊箇所からの氾濫流を同時に解く包括型氾濫解析モデルを用いて，氾濫シナリオを検討した．解析では，最初に，決壊を生じさせない条件で解析を行い，氾濫開始時刻の推定を行い氾濫シナリオを検討した．次に，決壊させた条件で解析を行い，氾濫水の挙動を明らかにするとともに，解析により得られた浸水深は現地調査結果をよく再現できることを明らかにした．</p>

DOI： 10.2208/jscejhe.75.1_387

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太田川中野観測所におけるSTIV流量観測とALBデータを用いた水理解析による精度検証査読

児子真也,吉田圭介,前野詩朗,間野耕司,中野光隆

土木学会論文集B1(水工学) 75 ( 4 ) I_613 - I_618 2019年12月

数値浮子モデルとDIEX法をカップリングさせた洪水流量推定法の構築と現地適用査読

赤穗良輔,前野詩朗,中山彰人,吉田圭介

土木学会論文集B1(水工学) 75 ( 4 ) I_625 - I_630 2019年12月

環境DNA 分析と物理環境調査による旭川下流部におけるアユの産卵可能性の検討査読

吉田圭介,乾隆帝,宇田川涼平,前野詩朗,赤松良久,児子真也,?橋幸生,永田貴美久

土木学会論文集B1(水工学) 75 ( 4 ) I_529 - I_534 2019年12月

Evaluation of discharge equation of lateral overflow located in the curved part of river, 査読

M. Ishihara, R. Akoh, S. Maeno and K. Yoshida

Proc. of 38th IAHR World Congress 2019年9月

ALBによる河道地形の再現性向上に伴う河床変動解析の改善効果の検討査読

山口華穂,吉田圭介,前野詩朗,間野耕司,赤穗良輔,西山哲

土木学会論文集A2（応用力学） 74 ( 2 ) I_465 - I_474 2019年2月

水路湾曲部に設置される横越流堤の流量公式の検討査読

石原正義,赤穂良輔,前野詩朗,吉田圭介

土木学会論文集B1(水工学) 74 ( 5 ) I_841 - I_846 2018年12月

ALB計測データを用いた流況解析に基づく旭川下流部におけるアユの産卵場の物理環境評価査読

吉田圭介,前野詩朗,高橋幸生,児子真也,小川修平,赤穗良輔

土木学会論文集B1(水工学) 74 ( 5 ) I_421 - I_426 2018年12月

Estimation of hydrodynamic forces acting on concrete blocks of toe protection works for coastal dikes by tsunami overflows 査読

Keisuke Yoshida, Shiro Maeno, Tomihiro Iiboshi, Daisuke Araki

Applied Ocean Research 80 181 - 196 2018年11月

担当区分：筆頭著者,　責任著者掲載種別：研究論文（学術雑誌）

The extraordinary tsunami generated by the Great East Japan Earthquake in 2011 destroyed coastal protection facilities in the Tohoku region. After the catastrophe, landward toe protection works comprising concrete blocks were proposed at damaged coastal areas. However, the hydrodynamic behavior of the protection works against tsunami overflows has not been fully elucidated by earlier experimental studies. Therefore, this study investigated validity of three-dimensional (3-D) numerical simulations of tsunami flows over a simulated coastal dike with protection works of concrete block models. This study also presented a method of estimating the hydrodynamic forces acting on block models under the tsunami overflows. After conducting basic validation of the present numerical method, we compared experimentally obtained results of hydrodynamic forces to results obtained from simulations. Results show that the simulation data are qualitatively consistent with experimental data for the considered cases of overflow depths of four kinds. They also presented that the characteristics of hydrodynamic forces depend mainly on both the distance from the dike foundation and tsunami overflow depth. The salient finding is that the hydrodynamic forces are affected to a considerable degree by the irregularity of the block model arrangement or surface asperity of the protection works. The impulsive force of tsunami overflows at actual coasts will perturb concrete blocks placed in orderly rows at the original installation. Therefore, the landward toe protection works using concrete blocks necessitate supportive constructions to enhance their structural stability.

DOI： 10.1016/j.apor.2018.09.001

Scopus

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Estimating flow resistance by vegetation in rivers using high-resolution airborne laser bathymetry 査読

K. Yoshida, S. Maeno, K. Mano, S. Ogawa, and R. Akoh

12th Int. Symp. on Ecohydraulics 2018年8月

Remote sensing of morphodynamics and habitats in rivers using airborne LiDAR bathymetry 査読

K. Yoshida, S. Maeno, S. Nigo, K. Mamno, S. Takahashi, and R. Akoh

12th Int. Symp. on Ecohydraulics 2018年8月

河床高データの解像度と計算格子サイズが河床変動解析に及ぼす影響に関する検討査読

中山彰人,赤穗良輔,前野詩朗,吉田圭介

河川技術論文集 24 107 - 112 2018年6月

ALB点群を用いた樹木群の密生度算定法の検討査読

吉田圭介,前野詩朗,小川修平,井関禎之,赤穗良輔

土木学会論文集B1(水工学) 74 ( 4 ) I_547 - I_552 2018年3月

微地形を考慮した氾濫解析手法の検討と鬼怒川洪水氾濫域を対象とした数値実験査読

赤穗良輔,前野詩朗,高橋巧武,吉田圭介,石川忠晴

土木学会論文集B1(水工学) 74 ( 4 ) I_1441 - I_1446 2018年3月

都市氾濫解析に用いる建物群の空隙率の設定方法に関する実験的検討査読

赤穗良輔,前野詩朗,小川俊,吉田圭介

土木学会論文集B1(水工学) 74 ( 4 ) I_1525 - I_1530 2018年3月

用水路網が南海トラフ地震下の津波氾濫に与える影響の検討査読

工代健太,前野詩朗,赤穗良輔,吉田圭介

土木学会論文集B1(水工学) 74 ( 4 ) I_439 - I_444 2018年3月

航空レーザ測深を用いた河道の植生種分布の判定手法の検討査読

吉田圭介,前野詩朗, 間野耕司, 岩城智大, 小川修平, 赤穗良

土木学会論文集A2（応用力学） 73 ( 2 ) I_607 - I_618 2018年2月

背面盛土内にジオテキスタイルを併設した粘り強い海岸堤防構造の検討査読

飯干富広,前野詩朗,田井祐介,吉田圭介,赤穂良輔

土木学会論文集B2（海岸工学） 73 ( 2 ) 1075 - 1080 2017年11月

Application of high-resolution ALB data of shallow water to river flow analysis 査読

K. Yoshida, S. Maeno, K. Mano, K. Yamaguchi, and R. Akoh

Proc. 3rd Int. Symp. on Shallow Flows 2017年6月

Improvement of float measurement method for river discharge using quasi-3D flood analysis 査読

R. Akoh, S. Maeno, and K. Yoshida

Proc. 3rd Int. Symp. on Shallow Flows 2017年6月

適正な分流量を維持するための百間川分流部の固定堰周辺における植生管理方策の検討査読

平井康隆,前野詩朗,吉田圭介,岩城智大,小川修平,赤穗良輔

土木学会論文集B1(水工学) 73 ( 4 ) I_1081 - I_1086 2017年3月

準三次元洪水流解析モデルを用いた浮子観測流量の高精度化手法の構築査読

赤穗良輔,前野詩朗,吉田圭介

土木学会論文集B1(水工学) 73 ( 4 ) I_517 - I_522 2017年3月

ALBを用いた河道地形計測の精度検証と流況解析の改善効果の検討査読

吉田圭介,前野詩朗,間野耕司,山口華穂,赤穗良輔

土木学会論文集B1(水工学) 73 ( 4 ) I_565 - I_570 2017年3月

フーリエ解析を用いた岡山市沿岸における津波ピークのリアルタイム予測法の検討査読

工代健太,前野詩朗,赤穗良輔,吉田圭介

土木学会論文集B1(水工学) 73 ( 4 ) I_1027 - I_1032 2017年3月

津波越流時における海岸堤防のブロックを用いた裏法尻保護工に作用する流体力の数値計算査読

吉田圭介,前野詩朗,竹内章人,赤穗良輔,飯干富広,荒木大輔

土木学会論文集A2（応用力学） 72 ( 2 ) I_485 - I_494 2017年2月

市街地レイアウトを考慮した岡山市における津波到達前後の浸水範囲予測および避難時間の検討査読

赤穗良輔,前野詩朗,高橋巧武,工代健太,吉田圭介

土木学会論文集B2（海岸工学） 72 ( 2 ) 289 - 294 2016年11月

津波越流による海岸堤防裏法尻保護工の衝撃時の被災特性に関する実験的研究査読

前野詩朗,吉田圭介,荒木大輔,田井祐介,飯干富広,赤穗良輔

土木学会論文集B2（海岸工学） 72 ( 2 ) 1135 - 1140 2016年11月

Forestation control works: secular change at the Gion area in the Asahi River 査読

K. Yoshida, S. Maeno, K. Yamaguchi, T. Iwaki, S. Fujita, Y. Hirai

Proc. 20th IAHR-APD Congress 2016年8月

Dam break experiment to characterize landward bed scouring for coastal dikes 査読

T. Iiboshi, S. Maeno, K. Yoshida, Y. Tai, A. Takeuchi, R. Akoh

Proc. 20th IAHR-APD Congress 2016年8月

Sequential data assimilation for estimating bed roughness of vegetated flooded rivers 査読

K. Yoshida, S. Maeno

Proc. 20th IAHR-APD Congress 2016年8月

Study of tidal effect on tsunami behavior striking offshore of Okayama city 査読

K. Kudai, S. Maeno, K. Yoshida, R. Akoh

Proc. 20th IAHR-APD Congress 2016年8月

Improvement of diversion weir and surrounding vegetation condition effects on diversion discharge in the Asahi River 査読

K. Yoshida, S. Maeno, R. Akoh, K. Yamaguchi, T. Iwaki, S. Fujita, Y. Hirai

Proc. 20th IAHR-APD Congress 2016年8月

旭川祇園地区における経年変化を考慮した礫河原再生効果の検討査読

前野詩朗,吉田圭介,平井康隆,岩城智大,山口華穂,藤田駿佑

土木学会論文集B1(水工学) 72 ( 4 ) I_1069 - I_1074 2016年3月

洪水時の河道内植生による流水抵抗の逆推定手法の検討査読

吉田圭介,前野詩朗

土木学会論文集B1(水工学) 72 ( 4 ) I_1063 - I_1068 2016年3月

南海トラフ地震下の鳴門・明石海峡部の津波波形を用いた岡山市に襲来する津波の予測モデルの検討析査読

工代健太,前野詩朗,赤穗良輔,吉田圭介

土木学会論文集B1(水工学) 72 ( 4 ) I_397 - I_384 2016年3月

植生消長モデルを用いた礫河原再生後の物理環境変化の検証査読

平井康隆,前野詩朗,吉田圭介,藤田駿佑,赤穗良輔

土木学会論文集B1(水工学) 72 ( 4 ) I_1063 - I_1068 2016年3月

Flood hydrograph estimation using an adjoint shallow-water model 招待査読

Keisuke Y., Tadaharu I.

Journal of Hydro-environmental Research 9 ( 3 ) 429 - 440 2015年9月

Numerical prediction of hydrodynamic force acting on a natural stone in open-channel flows 査読

K.Yoshida, S. Ushijima, R. Tanaka, N. Miyagi, S. Maeno

Proc. 36th IAHR World Congress 2015年7月

旭川における植生分布の経年変化を考慮した洪水流の数値解析査読

吉田圭介,前野詩朗,藤田駿佑,松山悟,岩城智大,平井康隆

土木学会論文集B1(水工学) 71 ( 4 ) I_1039 - I_1044 2015年3月

アイスハーバー型魚道の流れの解析と低流量・河床低下時の機能改善査読

前野詩朗,吉田圭介,田中龍二

土木学会論文集B1(水工学) 71 ( 4 ) I_1081 - I_1086 2015年3月

GPUによる分流を含む洪水流計算の高速化査読

吉田圭介,田中龍二,前野詩朗

土木学会論文集B1(水工学) 71 ( 4 ) I_589 - I_594 2015年3月

GPUによる河川の浅水流計算の高速化査読

吉田圭介,田中龍二,前野詩朗

土木学会論文集A1（応用力学） 70 ( 2 ) I_761 - I_768 2015年2月

開水路に置かれた自然石に作用する流体力の数値計算査読

吉田圭介,牛島省,田中龍二,宮木伸,前野詩朗

土木学会論文集A1（応用力学） 70 ( 2 ) I_701 - I_708 2015年2月

Effects of landward slope protection and toe protection work shape at coastal dikes on landward bed scouring caused by tsunami overflow 査読

Tomihiro Iiboshi, Shiro Maeno, Keisuke Yoshida, Daisuke Takata, Akira Yamamura

Proc. of the 36th IAHR World Congress 4103 - 4111 2015年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IAHR-INT ASSOC HYDRO-ENVIRONMENT ENGINEERING RESEARCH

Coastal dikes in Iwate, Miyagi, and Fukushima prefectures in Japan were damaged severely by tsunami overflow consequent to the 2011 off-the-Pacific coast of Tohoku Earthquake. A main factor of the failure was landward bed scouring following the tsunami overflow. Coastal dikes were destroyed completely or partially because of embankment material outflows caused by scouring of the landward bed. Because of this severe damage, the tsunami committee in Japan recommended several methods to produce resilient structures for coastal dikes. One method is landward toe protection works to reduce the landward toe bed scouring. It can improve the coastal dike stability. However, the relation of protection work shapes to landward bed scouring characteristics remains unclear. Therefore, we particularly examined the effects of landward slope and toe protection work shapes on landward bed scouring. We conducted small-scale experiments to clarify the effects of works with different characteristics. The obtained results demonstrate that a large scouring hole was formed around the landward toe area in any shape of the slope protection works without bed protection works. Landward bed protection works can reduce size of the scouring hole. A surface protuberances of landward toe protection works is more effective to reduce the scouring depths and areas.

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津波越流による海岸堤防裏法尻の洗掘に及ぼす裏法被覆工と法尻保護工形状の影響査読

飯干富広,前野詩朗,吉田圭介,高田大資

土木学会論文集B2（海岸工学） 70 ( 2 ) I_966 - I_970 2014年11月

Inverse estimation of distributed roughness coefficients in vegetated flooded rivers 査読

Keisuke Yoshida, Shiro Maeno

Journal of Hydraulic Research 52 ( 6 ) 811 - 823 2014年9月

Study on characteristics of hydrodynamic force on slope and landward toe protection works of coastal dikes due to tsunami overflow 査読

T. Iiboshi, S. Maeno, K. Yoshida, D. Takata

19th IAHR-APD Congress 2014年9月

Development and application of vegetation dynamics model for effective river management tasks in the Asahi River 査読

K. Yoshida, S. Maeno, S. Matsuyama, S. Fujita

River Flow 2014 571 - 579 2014年9月

Evaluation of hydrodynamic forces acting on bridge under flood in steep medium and small scale rivers 査読

S. Maeno, K. Yoshida, R. Tanaka

19th IAHR-APD Congress 2014年9月

Numerical simulation of tsunami inundation in Okayama city, Japan 査読

K. Kudai, K. Yoshida, S. Maeno

19th IAHR-APD Congress 2014年9月

Prediction of forestaion process in the Asahi river, Japan using a vegetation dynamics model 査読

K. Yoshida, S. Maeno, S. Fujita, S. Matsuyama

19th IAHR-APD Congress 2014年9月

津波越流時に海岸堤防法面および法尻保護工に作用する流体力特性に関する研究査読

飯干富広,前野詩朗,吉田圭介,高田大資

土木学会論文集B3（海洋開発） 70 ( 2 ) I_498 - I_503 2014年8月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：公益社団法人土木学会

東北地方太平洋沖地震時の大津波が堤防を越流し，裏法尻を洗掘させることで，岩手・宮城・福島県の海岸堤防は大きな被害を受けた．これは，これまでの設計では考慮されていなかった津波越流に起因する被害であり，堤防裏法面及び法尻保護工の重要性が認識されることとなった．しかし，これまでの研究では，越流した水塊が裏法尻部保護工に作用する流体力を評価したものはない．そこで，本研究では堤防裏法面被覆工および裏法尻保護工の形状の違いによる法面の圧力特性と裏法尻の流体力特性に着目し，水理模型実験による検討を行った．法尻保護工に作用する揚力は，津波波高の増加により一旦は増加するが，ある越流水深以上になると，逆に小さくなることが分かった．また，法尻保護工の表面粗度は，法尻部の流速を低減できるが，法尻保護工に作用する流体力は逆に大きくなるため，めくれや滑動対策を適切に行う必要があることがわかった．

DOI： 10.2208/jscejoe.70.I_498

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南海トラフ巨大地震を想定した岡山市の津波遡上解析査読

工代健太,吉田圭介,前野詩朗

土木学会論文集B3（海洋開発） 70 ( 2 ) I_289 - I_294 2014年8月

洪水時の急勾配中小河川の橋梁に作用する流体力の評価査読

前野詩朗,吉田圭介,田中龍二

土木学会論文集B1(水工学) 70 ( 4 ) I_883 - I_888 2014年3月

旭川大原試験区における植生消長シミュレーションモデルの構築と検証査読

前野詩朗,吉田圭介,松山悟,藤田駿佑

土木学会論文集B1(水工学) 70 ( 4 ) I_1369 - I_1374 2014年3月

Effects of groin installation on gravel bed restoration in the Tedori River 査読

S. Maeno, K. Yoshida, K. Kaseguma and A. Yamamura

12th Int. Symp. on River Sedimentation 2013年9月

Inverse estimation of flow resistance due to vegetation in the Asahi River during a flood 査読

K. Yoshida and S. Maeno

Proc. 35th IAHR Congress 2013年9月

Three-Dimensional Flow Analysis around Permeable Hydraulic Structure Comprising Connected Stones 査読

S. Maeno, K. Yoshida, K. Kaseguma and A. Yamamura

Proc. 35th IAHR Congress 2013年9月

Effect of flood impact on wash-out of vegetation and bed deformation in the Asahi River 査読

K. Yoshida, S. Maeno, S. Matsuyama and N. Mishima

12th Int. Symp. on River Sedimentation 2013年9月

射流場の護岸・根固めブロックに作用する流体力評価査読

忰熊公子,前野詩朗,吉田圭介,高田大資,山村明

土木学会論文集B1(水工学) 69 ( 4 ) I_691 - I_696 2013年3月

2011年9月旭川洪水における河道内植生の流水抵抗特性の検討査読

吉田圭介,前野詩朗

土木学会論文集B1(水工学) 69 ( 4 ) I_715 - I_720 2013年3月

手取川の洪水時の礫河原再生工の変形要因の検討査読

前野詩朗,忰熊公子,吉田圭介,山村明

土木学会論文集B1(水工学) 69 ( 4 ) I_721 - I_726 2013年3月

旭川の大原箇所における植生生長と洪水時の植生流出条件の検討査読

前野詩朗,吉田圭介,三島望,松山悟

土木学会論文集B1(水工学) 69 ( 4 ) I_727 - I_732 2013年3月

Estimation of river discharge hydrograph by using adjoint shallow-water model 査読

Keisuke Y. and Tadaharu I.

Proc. 18th IAHR-APD 2012年8月

Unsteady tidal effects on flood flow in the estuarine channel of Yangtze river 査読

Z. Wang, T. Ishikawa and K. Yoshida

Proc. 3rd Int. Symp. on Shallow Flows 2012年6月

Flood flow analysis using a quasi-three-dimensional flow model and aerial photos 査読

Keisuke Y., Tadaharu I. and Yasuhisa M.

Proc. 3rd Int. Symp. on Shallow Flows, 2012年6月

Adjoint法による流量ハイドログラフ推定法に関する研究査読

吉田圭介, 石川忠晴

水工学論文集 56 ( 4 ) I_1261 - I_1266 2012年3月

揚子江下流河道の洪水流に対する潮汐の非定常効果査読

王張嶠, 石川忠晴, 吉田圭介

土木学会論文集B1（水工学） 68 ( 1 ) 67 - 76 2012年

準3次元モデルによる利根川下流部1998年9月洪水流の再現査読

石川忠晴, 吉田圭介, 箕浦靖久

土木学会論文集B1（水工学） 67 ( 3 ) 155 - 167 2011年11月

浅水流adjointモデルによる河床粗度の時間変化の逆推定法に関する基礎的検討査読

吉田圭介

応用力学論文集 14 ( 2 ) I_533 - I_540 2011年9月

Inverse estimation of bed roughness coefficients of open-channel by using shallow-water adjoint model 査読

Yoshida, K. and Ishikawa, T.

Proc. 34th IAHR Congress 4392 - 4399 2011年6月

浅水流adjointモデルによる複断面河道の河床粗度の逆推定法に関する基礎的検討査読

吉田圭介

水工学論文集 55 S_1009 - S_1014 2011年3月

Inverse estimation of bed roughness coefficients of open-channel by using adjoint model in shallow-water flows 査読

吉田圭介

Journal of Hydroscience and Hydraulic Engineering 29 ( 1 ) 1 - 13 2011年

Quasi-3D flow solver by CIP-Soroban scheme and its application to flood flow in Tone River 査読

Yoshida, K. and Ishikawa, T.

Proc. 17th APD-IAHR Congress 3a043 2010年2月

変分法と浅水流モデルを併用した河床粗度の逆推定法に関する研究査読

吉田圭介, 石川忠晴

水工学論文集 54 991 - 996 2010年

Derivation of upstream boundary condition for 3-D numerical simulation of sediment dispersion around the Yangtze River mouth, China 査読

Wang, Z., Yoshida, K and Ishikawa, T.

Proc. 3rd Int. Conf. on Estuaries & Coasts 754 - 761 2009年9月

実体視と画像相関解析を併用した洪水航空写真解析手法の構築と検証査読

箕浦靖久, 石川忠晴, 吉田圭介

水工学論文集 53 997 - 1002 2009年

準3次元CIP-Sorobanモデルによる利根川洪水流の大規模数値計算査読

吉田圭介, 石川忠晴, 箕浦靖久

水工学論文集 53 877 - 882 2009年

Quasi-3D solver of meandering river flows by CIP-Soroban scheme in cylindrical coordinates with support of boundary fitted coordinate method 査読

Yoshida, K. and Ishikawa, T.

Proc. 16th APD-IAHR Congress 2008年9月

Flood flow analysis on aerial photos by image correlation method with support of stereo visualization 査読

Minoura, Y., Ishikawa, T. and Yoshida, K.

Proc. 16th APD-IAHR Congress 999 - 1004 2008年9月

Flow solver of arbitrarily meandering river by CIP-Soroban-BFC scheme with quasi-3D method 査読

Yoshida, K. and Ishikawa, T.

Proc. 8th International Conference on HydroScience and Engineering 2008年9月

Derivation of boundary condition for quasi-3D model of water exchange between Neijiang and Yangtze river 査読

Zhao, L., Yoshida, K., Ishikawa, T. and Futagi, K.

Proc. 16th APD-IAHR Congress 491 - 496 2008年9月

Study on turbidity increase during flood in Myoginohana area of lake Kasumigaura 査読

Yoshida, K., Ishikawa, T., Kobayashi, Y., Sasaki, F., Aoyama, S. and Ichiyama, M.

Proc. 16th APD-IAHR Congress 472 - 477 2008年9月

円筒座標CIP-Soroban法と境界適合座標法を組み合わせた蛇行河川の準3次元計算法査読

吉田圭介, 石川忠晴

水工学論文集 52 997 - 1002 2008年

Depth-averaged numerical solver of meandering river flows by CIP-Soroban grids in cylindrical coordinate system 査読

Yoshida,K, Ishikawa, T

Journal of Hydroscience and Hydraulic Engineering, JSCE 26 ( 1 ) 11 - 28 2008年

鎮江市内江の流動計算のための長江水理条件の導出査読

趙聯芳, 吉田圭介, 石川忠晴, 二木敬右

水工学論文集 52 1051 - 1056 2008年

Numerical prediction of meandering river flows by CIP-Soroban grids in cylindrical coordinate system 査読

Yoshida, K. and Ishikawa, T.

Proc. 32nd IAHR Congress 2007年7月

霞ヶ浦の妙技の鼻水域における出水時濁度上昇に関する研究査読

吉田圭介, 石川忠晴, 佐々木史, 青山貞雄, 市山誠

河川技術論文集 Vol.13 13 - 18 2007年

実体視と相関解析の併用による洪水航空写真解析の効率化査読

箕浦靖久, 石川忠晴, 吉田圭介

水工学論文集 Vol.51 1093 - 1098 2007年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japan Society of Civil Engineers

Stereo images obtained from sequential aerial photographs of river freshets contain a lot of useful information for river hydraulics as well as river engineering works. The image correlation analysis is a standard technique for analyzing the images, but it sometimes produces anomalous results for the area where color fluctuation of the water surface is small. On the other hand, a classical manual analysis through stereo eyeglasses usually works well even in such unclear parts of the images, but the manual analysis costs much labor and time. <BR>In this study, a new technique to analyze stereo images of river flows is developed by combining the above mentioned two methods: A small amount of suggestions are made by using the results from the manual analysis for the image correlation analysis on a computer, and then the results of the second trial of the latter is much improved without any significant time consumption.

DOI： 10.2208/prohe.51.1093

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円筒座標でCIP-Soroban法を拡張した蛇行河川の浅水流計算法査読

吉田圭介, 石川忠晴

水工学論文集 Vol.51 805 - 810 2007年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japan Society of Civil Engineers

A new numerical solver is developed for a shallow-water flow model to simulate meandering river flows. This solver can investigate the flows in the curved river channel, by means of the adaptive CIP-Soroban (CIP-S) scheme in a cylindrical coordinate system. Time development of water velocity and free-surface level is computed by the orthogonal curvilinear coordinate system without any transformation of the governing equations, and the advection term is calculated by the high-accuracy CIP scheme. The numerical grid points of the waterfront line at the river bank are moved and tracked by the kinematic condition so that the grid points are always located on the line, and the rearrangement of the positions of the girds is easily conducted by the original CIP-S method. From the verification of this solver by the pure advection problem and by the numerical solution of the meandering river flows, in comparison with the CIP-S method in a Cartesian coordinate system and with the boundary fitted coordinate (BFC) method, it is shown that the proposed numerical solver reasonably predicts the main flow profile and water surface elevation and will be a promising numerical method as one of the practical solutions.

DOI： 10.2208/prohe.51.805

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Fundamental investigation of depth-averaged numerical model with evolution of secondary currents in curved channels 査読

Yoshida, K. and Ishikawa, T.

Proc. 15th APD-IAHR Congress 2006年8月

2次流の時空間発展を考慮した水深積分モデルに関する基礎的検討査読

吉田圭介, 石川忠晴

水工学論文集, 第50巻 pp.781-786 781 - 786 2006年

Direct numerical simulation of two-fluid system and its application to air-water turbulent flows with deformed interfaces 査読

Yoshida, K., Ushijima, S. and Nezu, I.

Proc. 31st IAHR Congress 836 - 846 2005年9月

風シアーと底面シアーが共存する開水路混成流における組織乱流構造と気液界面気体輸送過程に関する研究査読

吉田圭介,禰津家久

土木学会論文集 803/II-73 57 - 67 2005年5月

気液2流体界面を含む混相場の直接数値計算査読

吉田圭介, 牛島省, 禰津家久

水工学論文集, 第49巻 49 709 - 714 2005年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japan Society of Civil Engineers

In this study, a direct numerical simulation for analyzing the immiscible incompressible two-fluid flows was carried out with the 3-dimensional MARS method, and the applicability of this scheme was verified in the water column collapse phenomenon, 2-dimesional channel flows between two walls and 3-dimensinal air-water co-current flows between a non-slip wall and a free-slip wall. It was shown that the present numerical simulation was in good agreement with previous experimental and numerical results, and that the volume of fluid in flows was sufficiently conserved for the long simulation time step. However, it is pointed out in the 3-D air-water co-current flows that lack of simulation grids and inadequate averaged time generates the inaccurate results in this DNS.

DOI： 10.2208/prohe.49.709

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逆流風波開水路混成場における乱れ構造と気体輸送に関する実験的研究査読

禰津家久, 福谷彰, 吉田圭介, 垂井晃一

応用力学論文集 8 911 - 918 2005年

逆流風波開水路混成場における乱流特性に関する研究査読

禰津家久, 垂井晃一, 吉田圭介

水工学論文集, 第49巻 49 505 - 510 2005年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japan Society of Civil Engineers

This study describes an experimental investigation on turbulence characteristics and the water-surface fluctuations in adverse wind-driven open-channel flows by using both a laser Doppler Anemometer (LDA) and a wave gauge simultaneously. In this study, it was shown that the velocity fluctuations of water flow near the interface in not only cocurrent flow but also adverse flow are significantly affected by the water surface in every range of frequency. However turbulence characteristics in water layer in adverse wind-driven open-channel flows are different from those in cocurrent flow, and there exists a high correlation between turbulence and the surface fluctuations in predominant frequency due to high-sheared wind flow.

DOI： 10.2208/prohe.49.505

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Experimental study on air-water interfacial turbulent hydrodynamics and gas transfer in wind-induced open-channel flows 査読

Yoshida, K. and Nezu, I.

Proc.4th International Symposium on Environmental Hydraulics 185 - 191 2004年12月

Numerical prediction of incompressible two-fluid system and its application to stratified flows with water and silicone-oil, 査読

K. Yoshida, S. Ushijima and I. Nezu

Proc. 14th APD-IHAR 309 - 309 2004年12月

水面上に風シアーが存在する開水路流場における水層乱れ構造と水面変動に関する研究査読

禰津家久, 吉田圭介, 垂井晃一

水工学論文集 Vol.48 517 - 522 2004年

風シアーを伴う開水路乱流場における水層組織渦構造に関する研究査読

吉田圭介, 禰津家久, 垂井晃一

応用力学論文集 Vol.7 1051 - 1060 2004年

Fundamental study on air-water interfacial coherent structures in wind-induced water-waves flows by PIV measurements 査読

Nezu, I. and Yoshida, K.

Proc. 30th IAHR Congress C-1 235 - 242 2003年8月

Computation of immiscible two-fluid flows with a unified numerical procedure 査読

Yoshida, K., Ushijima, S. and Nezu, I.

Proc. 30th IAHR Congress D 663 - 670 2003年8月

PIV法を用いた風波界面近傍流体の組織構造に関する基礎的研究査読

禰津家久, 吉田圭介, 池田大輔

水工学論文集 Vol.47 457 - 462 2003年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Japan Society of Civil Engineers

This paper describes an experimental study on turbulent bursting phenomena across air-water interface in wind-induced water waves by using Particle-Image Velocimetry (pry). The purpose of this study is to clarify coherent structures near the air-water interface in a wind-driven shear layer, and to evaluate an effect on momentum transport due to the busting events from the interfacial water to water-body flow. As the results of experiments, it is shown that the water flow is a combined flow with a wall shear flow and orbital motions, and that the wave-induced fluctuations have major power in the whole velocity fluctuations. In particular, when the bursting events are detected near the air-water interface by human eyes in the time-series of PIV raw images, only the low-frequency fluctuations are enhanced obviously at that time in wavelet-filter analysis. Therefore, it is inferred that the mechanism of water momentum transport is organized by the wave-induced fluctuations from the air-water interface to the water bulk, not by the bursting events with small fluctuations. It is also recognized by PIV measurements that the busting events are closely related to the unsteady wave-induced velocity fluctuations near the interface.

DOI： 10.2208/prohe.47.457

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風波発生下における自由水面近傍での組織構造に関する基礎的研究査読

禰津家久, 吉田圭介, 池田大輔, 垂井晃一

応用力学論文集 Vol.6 933 - 942 2003年

水面上に風シアーが存在する開水路流れ場における水・空気層乱流構造に関する基礎的研究査読

禰津家久, 吉田圭介, 牛島省

土木学会論文集 733/II-63 ( 733 ) 67 - 76 2003年

フラックス制御を利用する移流方程式の5次精度保存形スキーム査読

牛島省, 吉田圭介, 竹村雅樹, 禰津家久

土木学会論文集 747/II-65 ( 747 ) 85 - 94 2003年

非圧縮性混相流場に対する数値解法と水-シリコンオイル成層流への適用性に関する考察査読

牛島省, 吉田圭介, 禰津家久

応用力学論文集 6 891 - 898 2003年

Experimental Study on Mutual Turbulent Structures across Air-Water Interface in Wind-Induced Water Waves by Synchronous LDA Measurements 査読

Nezu,I, Yoshida,K, Ikeda,D

Journal of Hydroscience and Hydraulic Engineering, JSCE. Vol.21 ( No.1 ) 63 - 70 2003年

自由水面流れの数値計算における内部流動の解析精度に関する考察査読

牛島省, 禰津家久, 吉田圭介, 池田大輔

水工学論文集 Vol.47 409 - 414 2003年

Numerical prediction of free surface flows with QSI scheme on collocated grid system 査読

Ushijima, S., Yoshida, K., Takemura, M. and Nezu, I.

Proc. 10th international symposium on flow visualization F0162 2002年8月

Numerical prediction of free surface flows with QSI scheme on collocated grid system 査読

S. Ushijima, I. Nezu and K. Yoshida

Proc. 13th APD-IAHR Symp. 322 - 326 2002年8月

Turbulence visualization of multi-scale water velocity fluctuations of wind-driven water waves in air-water two-phase flows 査読

I. Nezu, K. Yoshida and S. Ushijima

Proc. 10th International symposium on flow visualization F0088 2002年8月

Experimental study on interfacial turbulent structures in wind-induced water waves by synchronous LDA measurements 査読

I. Nezu, S. Ushijima and K. Yoshida

Proc. 13th APD-IAHR Symp. 38 - 43 2002年8月

水・空気層の同時計測による風波界面近傍流体の相関構造に関する研究査読

禰津家久, 吉田圭介

水工学論文集 Vol.46 547 - 552 2002年

Study on turbulent structures of air-induced water waves by using phase-averaged PIV measurements 査読

Nezu, I., Ushijima, S., Onitsuka, K. and Yoshida, K

Proc. 3rd Int. Symp. on Measurement Techniques for Multiphase Flows 211 - 220 2001年8月

PIV measurements of turbulent structures across air-water interface in wind-driven water waves 査読

Nezu, I., Ushijima, S., Onitsuka, K. and Yoshida, K.

Pcoc. 6th Asian Symp. on Visualization 363 - 365 2001年5月

砕波を伴う風波の界面乱流構造に関する研究査読

禰津家久, 牛島省, 吉田圭介

土木学会論文集 684/II-56 ( 684 ) 69 - 80 2001年

PIV法を用いた砕波を伴う風波の界面乱流構造に関する研究査読

禰津家久, 井上理恵, 吉田圭介

応用力学論文集,Vol.3 3 775 - 786 2000年

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