Article
Environmental Sciences
Carl J. Legleiter, Brandon J. Sansom, Robert B. Jacobson
Summary: This study demonstrates the potential of remote sensing technology to assess tracer dye concentrations in complex river environments. Through spectral analysis and image processing techniques, detailed information on dye dispersion processes can be provided at a large scale.
WATER RESOURCES RESEARCH
(2022)
Article
Environmental Sciences
Margaux Filippi, Regina Hanlon, Irina I. Rypina, Benjamin A. Hodges, Thomas Peacock, David G. Schmale
Summary: The study successfully tracked the movement of a dye in the ocean by releasing Rhodamine dye and using the DrOne Water Sampling System system to collect water samples at different locations. Reliable estimates of dye concentration distribution can be obtained during drone sampling and post-processing. This opens up new possibilities for using drones to detect and mitigate hazardous agents in the ocean in the future.
Article
Chemistry, Analytical
Pawel Burdziakowski, Piotr Zima, Pawel Wielgat, Dominika Kalinowska
Summary: This study utilizes commercial UAVs with visible-light cameras to collect image data, develops an effective method for measuring fluorescent dye concentrations, and constructs a mathematical dispersion model. Reference measurements are performed using a laboratory fluorometer, and a new method for measuring fluorescent tracer concentrations is proposed, with concentration maps presented based on an orthophoto within a 2 x 2 m discrete grid.
Article
Water Resources
Christian J. Koppl, Ursula S. McKnight, Gregory G. Lemaire, Agnete M. Norregaard, Thea C. Thiim, Poul L. Bjerg, Peter Bauer-Gottwein, Monica Garcia
Summary: This study evaluated the performance of a hyperspectral imaging system and a consumer grade camera in mapping the concentration of a fluorescent tracer in a contaminated stream. The results showed that the hyperspectral system performed better than the RGB camera in mapping the concentration in all sections of the stream, regardless of illumination changes.
ADVANCES IN WATER RESOURCES
(2023)
Article
Remote Sensing
Min Xu, Hongxing Liu, David Mitchell, Yuehan Lu, Richard Beck, Sagy Cohen, Song Shu, Natasha Dimova
Summary: In this study, a multi-predictor ensemble model was developed to map and assess water turbidity for all rivers and streams in the Tombigbee River Basin using Landsat 8 multispectral images. The model showed a 79% improvement in turbidity estimation accuracy compared to the best traditional empirical model. It can be applied to other river and stream reaches across the basin with high prediction accuracy.
INTERNATIONAL JOURNAL OF REMOTE SENSING
(2023)
Article
Environmental Sciences
L. E. Palman, A. E. Trento, A. M. Alvarez
Summary: This study employed field tracer tests and numerical modeling to analyze scalar transport in a section of the Salado River, showing the impact of complex flow patterns and bathymetric irregularities on concentration curves. Both lateral and longitudinal dispersion coefficients played significant roles in particle transport in the river.
WATER AIR AND SOIL POLLUTION
(2021)
Article
Chemistry, Multidisciplinary
Laszlo Vas, Eniko Anna Tamas
Summary: The study aims to find an effective method for monitoring suspended sediment transport in rivers. The currently used methods are not accurate enough, so the researchers tested an integrated surrogate method based on turbidity registration to determine the suspended sediment yield in the lower reach of the Danube River. The results of the tests show that the method has great potential, but further measurements are needed to refine the relationships.
APPLIED SCIENCES-BASEL
(2023)
Article
Geosciences, Multidisciplinary
Thomas Depret, Emmanuele Gautier, Nathalie Thommeret, Herve Piegay, Clement Virmoux, Janet Hooke, Delphine Grancher
Summary: This study analyzed the spatiotemporal variability factors of bedload mobility in a low-energy gravel-bed meandering river, focusing on interactions between bedload transport distance and bedforms. The results showed that the influence of pre-existing morphology, especially bars, on event transport distance is limited, and the maintenance of bedforms requires successive minor changes.
Article
Engineering, Chemical
Toussaint Ntambwe Kambuyi, Raowia Lamhar, Zakia Zmirli, Bouchra Bejjany, Anas Aguelmous, Hassan Chaair, Khalid Digua, Adil Dani
Summary: A hydrodynamic modelling of a continuous-flow single-channel (CFSC) reactor using Residence Time Distribution (RTD) experimental approach was carried out. The flow patterns homogeneity and possible flow deviations were identified using the Axial Dispersion Model (ADM). The CFSC reactor showed a highly plug-flow behavior at high inlet flowrates, while dead zones and flow deviations were observed at a lower flowrate. The treatment efficiency of the reactor was found to depend on the coagulant dose electro-dissolved per unit of time rather than the hydrodynamic condition. The initial water quality also affected the treatment efficiency, with lower turbidity resulting in lower efficiency.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2023)
Article
Environmental Sciences
Yinghui Zhai, Pu Zhong, Hongtao Duan, Dan Zhang, Xin Chen, Xingjian Guo
Summary: This study used unmanned aerial vehicle (UAV) remote sensing with multispectral technology to successfully monitor the suspended particulate matter concentration (CSPM) in a sediment-bearing Yellow River tributary. The results showed that this method has high accuracy and effectiveness in highly turbid river environments, especially for monitoring before and after rainfall sediment production events.
Article
Environmental Sciences
Yingzhuo Hou, Qianguo Xing, Xiangyang Zheng, Dezhi Sheng, Futao Wang, Bommanna Krishnappan
Summary: Suspended sediments have significant impacts on marine primary productivity and ecological environment. This study utilizes multispectral imagery from SDGSAT-1 to estimate the suspended sediment concentration (SSC) in the Yellow River estuary and its vicinity waters. The results show a notable pattern of higher concentrations in nearshore areas and lower concentrations in offshore areas. The single-band model based on SDGSAT-1's R(854) demonstrates superior performance in estimating SSC, especially in waters with algal blooms.
Article
Chemistry, Analytical
Mingyue Sun, Qian Li, Xuzi Jiang, Tiantian Ye, Xinju Li, Beibei Niu
Summary: In this study, rapid and large-scale estimation of soil salt content (SSC) and organic matter (SOM) was conducted on arable land in the Yellow River Delta (YRD) using multi-source remote sensing. The integration of UAV hyperspectral and satellite multispectral data enabled the accurate estimation of SSC and SOM for a large-scale area. The results revealed significant correlations and distributions of SSC and SOM in the YRD region.
Article
Environmental Sciences
Joel B. Sankey, Temuulen T. Sankey, Junran Li, Sujith Ravi, Guan Wang, Joshua Caster, Alan Kasprak
Summary: Rangelands cover 70% of the world's land surface and play a critical role in providing ecosystem services. Utilizing UAV remote sensing techniques allows for the detection of fine-scale changes in soil nutrients and plant species in degraded rangelands. Combining UAV multispectral and LiDAR technology improves the accuracy of classifying plant functional types and soil fertility microsite types, providing valuable insights for better management of rangeland ecosystems.
REMOTE SENSING OF ENVIRONMENT
(2021)
Article
Environmental Sciences
Ksenia Nazirova, Yana Alferyeva, Olga Lavrova, Yuri Shur, Dmitry Soloviev, Tatiana Bocharova, Alexey Strochkov
Summary: The paper compares water turbidity and suspended particulate matter concentration obtained from in situ and satellite remote-sensing data, demonstrating that with the right algorithm, these values can adequately reflect the real situation, even with standard retrieval algorithms. Special algorithms may be needed for high correlation in specific conditions, like in spring flooding.
Proceedings Paper
Materials Science, Multidisciplinary
Vikash Kumar, Renu Gupta, Ajay Bansal
Summary: TiO2 nanoparticles were synthesized and utilized in the active layer of DSSC's photoanode, with ZnS nanoflowers decorating the scattering layer. The study found that different concentrations of Rhodamine B dye influenced the performance of DSSCs, with some achieving a photo conversion efficiency of over 1%.
MATERIALS TODAY-PROCEEDINGS
(2021)
Article
Environmental Sciences
Carl J. Legleiter, Paul J. Kinzel
Article
Geography, Physical
Christina M. Leonard, Carl J. Legleiter, Devin M. Lea, John C. Schmidt
EARTH SURFACE PROCESSES AND LANDFORMS
(2020)
Article
Environmental Sciences
Lee R. Harrison, Carl J. Legleiter, Brandon T. Overstreet, Tom W. Bell, John Hannon
RIVER RESEARCH AND APPLICATIONS
(2020)
Article
Environmental Sciences
Paul J. Kinzel, Carl J. Legleiter, Paul E. Grams
Summary: The study conducted field trials using a prototype compact topo-bathymetric lidar sensor to measure river depths accurately. Comparisons between measured data and sensor depth data indicated varying application effects of the sensor under different water depths, with river optical properties affecting measurement accuracy.
RIVER RESEARCH AND APPLICATIONS
(2021)
Article
Environmental Sciences
Carl J. Legleiter
Summary: ORByT is a standalone software package that can map water depth from passive optical image data with a thorough accuracy assessment. However, this approach is only suitable for clear-flowing, shallow streams and not appropriate for more turbid, deeper rivers.
RIVER RESEARCH AND APPLICATIONS
(2021)
Article
Environmental Sciences
C. J. Legleiter, P. J. Kinzel
Summary: The IBARI method of inferring river bathymetry from averaged images can increase the accuracy and precision of depth maps, while also improving the representation of channel morphology. This approach is suitable for data collected from helicopters and small unmanned aircraft systems.
WATER RESOURCES RESEARCH
(2021)
Article
Fisheries
David A. Boughton, Lee R. Harrison, Sara N. John, Rosealea M. Bond, Colin L. Nicol, Carl J. Legleiter, Ryan T. Richardson
Summary: The study used high-resolution methods to assess the capacity for anadromous steelhead and spring-run Chinook Salmon reintroduction in the Tuolumne and Merced rivers in the Sierra Nevada of California. Results showed that both systems could support viable populations of these species, with the Merced River being too warm for adult Chinook Salmon in the dry season.
TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY
(2022)
Article
Environmental Sciences
Carl Legleiter, Paul Kinzel
Summary: Remote sensing using particle image velocimetry (PIV) has shown potential for estimating flow velocities in sediment-laden rivers. A new framework introduced in this study, called DIVERS, aims to infer bathymetric information based on flow resistance equations and assumptions regarding flow conditions. The framework demonstrated reasonable accuracy in estimating water depths in a large river in Alaska, with the ability to also reproduce discharge values recorded at a gaging station. Additionally, the accuracy of PIV-derived velocities varied along the channel, with room for improvement in future iterations of the approach.
Article
Environmental Sciences
Carl J. Legleiter, Shawn W. Hodges
Summary: Rivers are sensitive to environmental changes and blooms of benthic algae have become widespread in US national parks, degrading visitor experiences and threatening human and ecosystem health. This study evaluated the potential of remote sensing techniques for mapping algal density in shallow rivers and proposed future improvements.
Article
Environmental Sciences
Carl J. Legleiter, Brandon J. Sansom, Robert B. Jacobson
Summary: This study demonstrates the potential of remote sensing technology to assess tracer dye concentrations in complex river environments. Through spectral analysis and image processing techniques, detailed information on dye dispersion processes can be provided at a large scale.
WATER RESOURCES RESEARCH
(2022)
Article
Environmental Sciences
Carl J. Legleiter, Paul J. Kinzel, Mark Laker, Jeffrey S. Conaway
Summary: Information on velocity fields in rivers is crucial for various applications. This study presents a framework for measuring river velocity using aerial images, which has been successfully tested in two Alaskan rivers.
WATER RESOURCES RESEARCH
(2023)
Article
Environmental Sciences
Lee R. Harrison, Carl J. Legleiter, Vamsi K. Sridharan, Peter N. Dudley, Miles E. Daniels
Summary: Multi-dimensional numerical models are important tools for studying biophysical processes in aquatic ecosystems. This study evaluated the potential of using remote sensing techniques to develop hydrodynamic models for a large river. The results showed that 2D and 3D models had similar accuracy in simulating water depth, and the models could predict velocity with good agreement. High-resolution bathymetry improved the model performance, and the input bathymetry influenced predictions related to adult holding costs. The study demonstrated that hyperspectral imagery obtained from piloted and/or uncrewed aircraft can accurately map the bathymetry of clear-flowing, relatively shallow large rivers.
WATER RESOURCES RESEARCH
(2022)
Article
Environmental Sciences
Carl J. Legleiter, Paul J. Kinzel
Summary: Accurate knowledge of water speed in rivers is vital for ecological and resource management purposes. Remote sensing is a more efficient method for measuring flow velocity, and powerful computational techniques have been developed for inferring velocity fields from videos or image time series. This paper introduces a software tool, TRiVIA, designed to facilitate the use of particle image velocimetry (PIV) by the river community. TRiVIA provides a complete workflow for producing spatially distributed velocity vectors from videos or images, with modules for data extraction, stabilization, enhancement, PIV analysis, visualization, accuracy assessment, and output export. The toolbox, now freely available, can be augmented to incorporate bathymetric information for discharge calculation functionality.
RIVER RESEARCH AND APPLICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Milad Niroumand-Jadidi, Carl J. Legleiter, Francesca Bovolo
Summary: This study evaluates the potential of using Landsat-9 imagery to map river bathymetry and finds that Landsat-9 provides more accurate bathymetry measurements, particularly when pan-sharpened. Additionally, downsampling SuperDove data and the enhanced spectral resolution of the 8-band SuperDoves improved depth retrieval. The neural network-based model outperformed the optimal band ratio analysis in bathymetry retrieval.
IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING
(2022)