Continuous measurements of flow rate in a shallow gravel‐bed river by a new acoustic system

Kawanisi, Kiyosi; Razaz, Mahdi; Ishikawa, Kazuhiko; Yano, J.; Soltaniasl, Mohammad

doi:10.1029/2012wr012064

Cited by 30 publications

(33 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, establishing a method and/or technology for quantifying discharge is of paramount importance. The purpose of this study is to demonstrate the feasibility of monitoring streamflow by the use of fluvial acoustic tomography system (FATS) (Kawanisi , et al , , Kawanisi , et al , , Kawanisi , et al , ).…”

Section: Introductionmentioning

confidence: 99%

High‐frequency streamflow acquisition and bed level/flow angle estimates in a mountainous river using shallow‐water acoustic tomography

Kawanisi

Bahrainimotlagh

Sawaf

et al. 2016

Hydrological Processes

View full text Add to dashboard Cite

Abstract:The acquisition of reliable discharge estimates is crucial in hydrological studies. This study demonstrates a promising acoustic method for measuring streamflow at high sampling rate for a long period using the fluvial acoustic tomography system (FATS). The FATS recently emerged as an innovative technique for continuous measurements of streamflow. In contrast to the traditional point/transect measurements of discharge, the FATS enables the depth-averaged and range-averaged flow velocity along the ray path to be measured in a fraction of a second. The field test was conducted in a shallow gravel-bed river (0.9 m deep under lowflow conditions, 115 m wide) for 1 month. The parameters (stream direction and bottom elevation) required for calculating the streamflow were deduced by a nonlinear regression to the discharge data from the well-established rating curve. The crosssectional average velocities were automatically calculated from the acoustic data, which were collected on both riverbanks every 30 s. The FATS was connected to the internet so that the real-time flow data could be obtained. The FATS captured discharge variations at a cut-off frequency of approximately 70 day À1 . The stream exhibited temporal discharge changes at multiple time scales ranging from a few tens of minutes to days.

show abstract

Section: Introductionmentioning

confidence: 99%

High‐frequency streamflow acquisition and bed level/flow angle estimates in a mountainous river using shallow‐water acoustic tomography

Kawanisi

Bahrainimotlagh

Sawaf

et al. 2016

Hydrological Processes

View full text Add to dashboard Cite

show abstract

“…It is worth mentioning that work previously conducted by Kawanisi et al [2012] showed that the relative error may reduce to 610% in freshwater zone characterized with no density gradients or remarkable changes in flow direction.…”

Section: Comparison Of the Direction And Mean Flow Velocity With Crosmentioning

confidence: 99%

“…Based on CAT, fluvial acoustic tomography (FAT) is designed for continuous measurement of the crosssectional average velocities in shallow rivers using higher frequencies (10-30 kHz). Its ability to reconstruct a scalar function using tomographic techniques with only one acoustic path already resulted in a wealth of applications, e.g., measuring flow rate in freshwater rivers [e.g., Kawanisi et al, 2012] and measuring tidal bores with 4 kHz transducers [Zhu et al, 2012]. However, when only data from one acoustic transmission line is available, transformation of along-ray velocity data to streamwise velocity involves a major assumption, i.e., current is unidirectional and forms a constant angle with the sound ray.…”

Section: Introductionmentioning

confidence: 99%

An acoustic travel time method for continuous velocity monitoring in shallow tidal streams

Razaz

Kawanisi

Nistor

et al. 2013

Water Resources Research

View full text Add to dashboard Cite

[1] Long-term variations of streamflow in a tidal channel were measured using a Fluvial Acoustic Tomography (FAT) system through one transmission path. FAT is an innovative acoustic technology that utilizes the time-of-travel method to determine velocity between two points from multiple ray paths that traverse the entire cross-section of stream. Due to high spatial variability of flow distribution stationary ADCP measurements were not likely to yield true section-averaged flow velocity and moving-boat ADCP method was therefore used to provide reference data. As such, two short-term moving boat ADCP campaigns were carried out by the authors. In the first campaign, a couple of acoustic stations were added to the FAT system in order to resolve flow angularity in addition to the mean velocity. Comparing the FAT results with corresponding ADCP section-averaged flow direction and velocity indicated remarkable consistency. Second campaign was designed to capture the influence of salt wedge intrusion on the sound propagation pattern. It was found that FAT velocity measurements bias high if acoustic stations lay inside the cooler freshwater layer. Ray-tracing hindcasts suggest that installing acoustic stations inside the salt wedge may significantly improve function of output of the system. Comparing salinities evaluated from long-term FAT travel time records with nodal salinity measurements provided by conductivity-temperature sensors reveals the potential ability of FAT in measuring salt flux.

show abstract

“…Using cross-sectional area and cross-sectional velocity obtaining from the acoustic tomography method, flow rate can be estimated 18) :…”

Section: ) (6) Flow Ratementioning

confidence: 99%

Acoustic Investigations of Tidal Bores in Qiantang River

2015

View full text Add to dashboard Cite

The continuous measurements of flow velocity/rate and suspended sediment concentration (SSC) in tidal rivers are crucial in estuarine studies. However, the accurate estimates of these terms are difficult and labor-intensive procedures are needed; thus, a robust and efficient method of the measurements is required. The changes of cross-sectional average suspended sediment concentration, tidal bore celerity and flow velocity were measured in the Qiantang River by using acoustic tomography systems. The struser showed that the amount of SSC increased more than threefold during tidal bores. The acoustic systems could successfully measure the cross-sectional average velocity in the unsteady flows though the high SSC bred a short missing period after the bore arrival.

show abstract

Continuous measurements of flow rate in a shallow gravel‐bed river by a new acoustic system

Cited by 30 publications

References 19 publications

High‐frequency streamflow acquisition and bed level/flow angle estimates in a mountainous river using shallow‐water acoustic tomography

High‐frequency streamflow acquisition and bed level/flow angle estimates in a mountainous river using shallow‐water acoustic tomography

An acoustic travel time method for continuous velocity monitoring in shallow tidal streams

Acoustic Investigations of Tidal Bores in Qiantang River

Contact Info

Product

Resources

About