Article
Engineering, Multidisciplinary
Yeon-joong Kim, Ichiro Fujita, Makoto Hasegawa, Jong-sung Yoon
Summary: This study aims to measure the velocity of soil and rocks by applying space-time image velocimetry (STIV), which has not yet been applied to the soil and rocks waterway experiment. The performance of the velocity evaluation was significantly improved by applying machine learning to the STI slope estimation method, and the velocity can be easily measured with high accuracy by freely setting an area to be measured in the captured image.
Article
Engineering, Civil
Kailin Huang, Hua Chen, Tianyuan Xiang, Yunfa Lin, Bingyi Liu, Jun Wang, Dedi Liu, Chong-Yu Xu
Summary: The ease of access to media resources and computational power has sparked interest in using vision-based approaches for hydraulic monitoring. This paper proposes a photogrammetry-based method called L1-Diffusion to estimate the free surface velocity of a river by incorporating prior knowledge and image information. The proposed method has been validated to accurately and efficiently estimate the free surface velocity in various scenarios.
JOURNAL OF HYDROLOGY
(2022)
Review
Environmental Sciences
Hamish Biggs, Graeme Smart, Martin Doyle, Niklas Eickelberg, Jochen Aberle, Mark Randall, Martin Detert
Summary: This paper reviews methods for estimating the conversion from surface velocity to depth-averaged velocity, and presents a workflow for selecting the appropriate method. The methods include reference discharge and surface velocimetry measurements, extrapolated ADCP velocity profiles, log law profiles, power law profiles, site characteristics, and default assumed values. The paper summarizes approaches for accounting for spatial and temporal heterogeneity in the conversion factor and discusses remaining challenges and future directions.
Article
Environmental Sciences
Seth A. Schweitzer, Edwin A. Cowen
Summary: This paper introduces a new method called Infrared Quantitative Image Velocimetry (IR-QIV) for high-resolution real-time calculation of velocity fields over large water bodies under most weather conditions, with results showing agreement with acoustic velocity measurements, improving both fixed and mobile platform velocimetry.
WATER RESOURCES RESEARCH
(2021)
Article
Water Resources
Win Cowger, Andrew Gray, Stanley Brownlee, Hannah Hapich, Ashok Deshpande, Kryss Waldschlager
Summary: This study focuses on estimating the macroplastic flux in the Santa Ana River middle reach by monitoring the macroplastic concentration and using strategies commonly employed in estimating mineral sediment flux. The results show that channel processes control the size distribution of macroplastic, and different flow stages have different effects on plastic concentration. The annual flux of floating macroplastic is estimated to be 27.4 tonnes per year.
JOURNAL OF HYDROLOGY-REGIONAL STUDIES
(2022)
Article
Environmental Sciences
Boaz Kuizenga, Paolo F. Tasseron, Katrin Wendt-Potthoff, Tim H. M. van Emmerik
Summary: Rivers serve as pathways and storage areas for plastic pollution. Understanding and quantifying plastic transport in rivers is crucial for prevention strategies and evaluating the effectiveness of interventions. This study evaluated floating plastic transport and polymer composition along the Rhine river, showing significant variability and an increase towards the river mouth.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2023)
Article
Environmental Sciences
Carmen Rocamora, Herminia Puerto, Ricardo Abadia, Margarita Brugarolas, Laura Martinez-Carrasco, Jose Cordero
Summary: The Vega Baja region in southeastern Spain faces significant challenges with floating waste accumulation, primarily from reeds and riparian vegetation residues, with anthropogenic waste accounting for a small portion. Understanding the type and origin of floating waste is crucial for developing effective measures to prevent it from reaching the Mediterranean Sea.
Article
Engineering, Civil
Pengfei Gu, Aimin Liao, Hongwei Liu, Wei Wu, Yongxiang Wu, Guodong Liu, Jianan Cao, Gaoxu Wang, Xi Jiang, Pengcheng Hu
Summary: This study proposes a new method for measuring river cross-section data using unmanned aerial vehicles (UAVs). The effectiveness of this method has been verified in different rivers, showing good results. The accuracy of the measurements is affected by the surface velocity, with measurement errors of -4%, -8%, and -18% of the actual water depth for surface velocities less than 1 m/s, 1-2 m/s, and greater than 2 m/s, respectively. The results also indicate that discharge calculated from the measured cross-section has the highest accuracy, followed by the UAVB cross-section, and the generalized cross-section has the worst accuracy.
JOURNAL OF HYDROLOGY
(2023)
Article
Geochemistry & Geophysics
Chen Liu, Biyang Wen, Zhigang Duan, Yingwei Tian
Summary: River discharge is an important hydrological index for the global water cycle and flood/drought forecast. This letter proposes an improved index-velocity method to address the challenge of measuring discharge in mountainous rivers, where the water level changes significantly due to the deep-narrow channel. Experimental results demonstrate that this method achieves higher calculation accuracy and expands the applicability of UHF radar in discharge measurement.
IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
(2023)
Article
Environmental Sciences
Pia M. Eibes, Friederike Gabel
Summary: The study investigated the contamination of microplastic debris in the River Ems in Northwest Germany, showing that the pollution pattern did not increase linearly with river length and indicating possible sinks due to sedimentation. Further research is needed to identify sources, sinks, and transport of microplastics in smaller rivers to find solutions to reduce microplastic loads.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Jitendra Kr Vyas, Muthiah Perumal, Tommaso Moramarco
Summary: The application of entropy theory in hydrometric measurements establishes a relationship between maximum and mean flow velocities, and a proposed two-steps approach for discharge estimation based on this relationship shows promising results in both Italy and India. The proposed method proves to be a viable alternative to the traditional velocity-area method, providing accurate discharge estimations with high efficiency values.
WATER RESOURCES RESEARCH
(2021)
Article
Environmental Sciences
G. Dolcetti, B. Hortobagyi, M. Perks, S. J. Tait, N. Dervilis
Summary: This study examines the potential of estimating river surface velocity, water depth, depth average velocity, and discharge using only a sequence of dynamic water surface images. The method is based on comparing Fourier spectra of pixel intensities with theoretical dispersion relations, showing promising results for remote monitoring of river discharge.
WATER RESOURCES RESEARCH
(2022)
Article
Environmental Sciences
Michio Sanjou, Kyohei Kato, Wataru Aizawa, Takaaki Okamoto
Summary: The present study developed a safety survey system for measuring natural river discharge. The system utilizes a drone-type float with a GPS receiver to monitor the river and measure the discharge. Field tests have confirmed the reliability and practical application of this system.
ENVIRONMENTAL FLUID MECHANICS
(2022)
Article
Engineering, Civil
Taylor Vaughn, Brian M. Crookston, Michael Pfister
Summary: The sensitivity of labyrinth weirs to floating woody debris blockage in channel and reservoir applications depends primarily on trunk diameter and upstream head. Lower heads are more susceptible to debris blockage, with the increase in head due to debris being up to 17% for smaller flow depths and approximately 7% or less for higher reference heads.
JOURNAL OF HYDRAULIC ENGINEERING
(2021)
Article
Engineering, Civil
Hezhen Lou, Hao Li, Shengtian Yang, Xuelei Wang, Zihao Pan, Yujia Zhang, Baichi Zhou, Jun Zhang, Xiaodong Zhang
Summary: In order to address the negative impacts of climate change and human activities on water resources in basins, positive measures such as interbasin water transfer projects and efficient water resource policies have been implemented worldwide, resulting in noticeable effects on the discharges of large rivers. However, the impact on small and medium-sized rivers remains unclear due to insufficient river discharge data. This study focused on the Haihe River Basin in North China and utilized remote sensing hydrological station technology to obtain monthly scale discharge data for 16 small and medium-sized river sections in the past 20 years. The results showed both downward and upward trends in river discharges, with lags in recovery attributed to heavy groundwater exploitation in the basin.
JOURNAL OF HYDROLOGY
(2023)
Article
Geosciences, Multidisciplinary
Ryota Tsubaki, Yoshihisa Kawahara, Yasuhiro Ueda
Article
Environmental Sciences
Ryota Tsubaki, Yoshihisa Kawahara, Xin-Hua Zhang, Kentaro Tsuboshita
WATER RESOURCES RESEARCH
(2017)
Article
Environmental Sciences
Ryota Tsubaki
WATER RESOURCES RESEARCH
(2017)
Article
Environmental Sciences
Ichiro Fujita
Article
Engineering, Mechanical
Ryota Tsubaki, Sandor Baranya, Marian Muste, Yuji Toda
EXPERIMENTS IN FLUIDS
(2018)
Article
Environmental Sciences
Li Bing-dong, Zhang Xin-hua, Tang Han-song, Ryota Tsubaki
JOURNAL OF MOUNTAIN SCIENCE
(2018)
Article
Engineering, Multidisciplinary
Ryota Tsubaki
MEASUREMENT SCIENCE AND TECHNOLOGY
(2020)
Article
Environmental Sciences
Ken Watanabe, Ichiro Fujita, Makiko Iguchi, Makoto Hasegawa
Summary: Image-based river flow measurement methods are easy to use and safe, but may generate incorrect values depending on shooting environment. This study incorporated deep learning into the STIV technique and showed that it can improve efficiency, making it suitable for building a real-time measurement system.
Article
Geography, Physical
Runye Zhu, Ryota Tsubaki
Summary: Bio-hydro-morphodynamic simulation is a valuable tool for analyzing fluvial processes, and the flexibility of vegetation plays a significant role in water flow and bed shear stress. The study results indicate that vegetation flexibility has a substantial impact on river hydrodynamics and morphology development.
EARTH SURFACE PROCESSES AND LANDFORMS
(2022)
Article
Engineering, Civil
Ichiro Ario, Tatsuya Yamashita, Ryota Tsubaki, Shin-ichi Kawamura, Tatsuhiko Uchida, Gakuho Watanabe, Akimasa Fujiwara
Summary: The heavy rainfall in western Japan in July 2018 caused significant damage to social infrastructures and lifelines. This study conducted a field survey and structural analysis on a washed out railway bridge to evaluate the failure conditions and provide design elements for future bridge structures.
JOURNAL OF BRIDGE ENGINEERING
(2022)
Article
Geography, Physical
S. Baranya, G. Fleit, M. Muste, R. Tsubaki, J. Jozsa
Summary: This paper describes the in-situ implementation of Acoustic Mapping Velocimetry (AMV), a newly developed method for estimating bedload transport in rivers. The method combines components and processing protocols from acoustic and image-based methods to provide velocity maps of migrating bedforms. The paper presents case studies of AMV implementation in the Ohio and Mississippi rivers, highlighting the importance of spatio-temporal parameters and the contribution of secondary bedforms to sediment transport. It demonstrates the applicability of AMV as an alternative method for quantifying bedload transport in large sand-bed rivers.
Article
Environmental Sciences
M. Muste, H. You, D. Kim, G. Fleit, S. Baranya, R. Tsubaki, D. Abraham, T. O. McAlpin, K. E. Jones
Summary: A new measurement protocol called Acoustic Mapping Velocimetry (AMV) has been successfully tested for estimating bedload transport features in sandy beds. The AMV utilizes the dune-tracking method (DTM) to characterize bedform geometry, dynamics, and estimate bedload transport rates. This paper compares the AMV technique with three other non-intrusive DTM-based methods and analytical predictors, and finds that the AMV estimates are within 22% of the estimates from other protocols and differ up to 98% from analytical predictions. These differences are attributed to uncertainties in the AMV workflows and methods to reduce their impact.
WATER RESOURCES RESEARCH
(2023)
Article
Geochemistry & Geophysics
Runye Zhu, Ryota Tsubaki, Yuji Toda
Summary: The interaction between vegetation, sediment, and water flow in fluvial landscapes is regulated by hydrological conditions, flood disturbances, and vegetation habitat preferences. This study focuses on the spatial distribution of vegetation cover along river transects during low flow periods. Using a hydro-morphodynamic model, the effects of different vegetation transect distributions on the morphological development of a vegetated braided river were investigated. The model successfully reproduced changes in the river's braiding index, showing that vegetation near the low water channel played a critical role in redirecting water flow and changing the statistical characteristics of the riverbed elevation distribution.
Article
Water Resources
Ryota Tsubaki, Runye Zhu
Summary: A new approach for ortho-rectification using an optical system was proposed in this study. The characteristics of the proposed approach were validated through field measurements and compared to a conventional approach.
FRONTIERS IN WATER
(2021)
Article
Water Resources
Sarawut Jamrussri, Yuji Toda, Ryota Tsubaki
JOURNAL OF APPLIED WATER ENGINEERING AND RESEARCH
(2019)
