scholarly journals MEASUREMENT OF SUSPENDED SEDIMENT ON TIDAL FLAT WITH AN ACOUSTIC DOPPLER CURRENT PROFILER

2008 ◽  
Vol 52 ◽  
pp. 949-954 ◽  
Author(s):  
Kiyoshi KAWANISHI ◽  
Tomoya YOKOYAMA ◽  
Masamitsu MIZUNO ◽  
Shoji FUKUOKA
Keyword(s):  
Suspended Sediment ◽  
Tidal Flat ◽  
Acoustic Doppler Current Profiler ◽  
Current Profiler

scholarly journals Quantifying Suspended Sediment using Acoustic Doppler Current Profiler in Tidung Island Seawaters

2021 ◽  
Vol 29 (1) ◽  
Author(s):  
Henry Munandar Manik ◽  
Randi Firdaus
Keyword(s):  
Water Column ◽  
Suspended Sediment ◽  
Suspended Solids ◽  
Acoustic Doppler Current Profiler ◽  
Sediment Concentration ◽  
In Situ Measurement ◽  
Ocean Current ◽  
Echo Intensity ◽  
Current Profiler

Tidung Island, located near Jakarta Bay, is a tourism and conservation area. It is necessary to keep these seawaters unpolluted. To calculate the level of pollution, it is necessary to know the sediment concentration. Quantifying concentration suspended sediment is important for knowledge of sediment transport. Researchers usually use water sample analysis and optical method for quantifying suspended sediment in seawater. Less accuracies of these methods are due to under sample of seawater and the existence of biological fouling. One promising method to measure concentration of suspended sediment is using Acoustic Doppler Current Profiler (ADCP). ADCP is usually used by oceanographer and hydrographer to measure ocean current. In this research, ADCP with 300 kHz operating frequency was used effectively to measure suspended sediment concentration (SSC) and ocean current simultaneously. The echo intensity received from suspended sediment was computed using sonar equations to quantify SSC. The empirical equation between echo intensity and SSC was found. The SSC value obtained by ADCP was also compared with in situ measurement. The result showed that quantified SSC value obtained by ADCP was nearly equal with SSC obtained from in situ measurement with coefficient correlation of 0.98. The high concentration ranged from 55 mg/L to 80 mg/L at the surface layer to a depth 12 m, moderate concentration ranged from 45 mg/L to 55 mg/L at a depth 12 m to 40 m, and low concentration less than 45 mg/L at a depth greater than 40 m. The distribution of SSC was correlated with ocean current condition. In small currents, suspended solids will settle faster so that the concentration in the water column will decrease. Conversely, if the velocity is high, suspended solids will continue to float carried by the current in the water column so that the concentration is high.

scholarly journals Prediction and classification of suspended sediment and zooplankton signals from acoustic Doppler current profiler backscatter data using artificial neural networks

2021 ◽  
Vol 944 (1) ◽  
pp. 012014
Author(s):  
A Dwinovantyo ◽  
S Solikin ◽  
H M Manik ◽  
T Prartono ◽  
Susilohadi
Keyword(s):  
Suspended Sediment ◽  
Suspended Sediment Concentration ◽  
Acoustic Doppler Current Profiler ◽  
Suspended Sediments ◽  
Sediment Concentration ◽  
Optimal Number ◽  
Environmental Data ◽  
Zooplankton Abundance ◽  
Current Profiler ◽  
Artificial Neural

Abstract Characterization of each underwater object has its challenges, especially for small objects. The process of quantifying acoustic signals for these small objects can be done using high-frequency hydroacoustic instruments such as an acoustic Doppler current profiler (ADCP) combined with the artificial intelligence (AI) technique. This paper presents an artificial neural network (ANN) methodology for classifying an object from acoustic and environmental data in the water column. In particular, the methodology was tuned for the recognition of suspended sediments and zooplankton. Suspended sediment concentration and zooplankton abundance, which extracted from ADCP acoustic data, were used as input in the backpropagation method along with other environmental data such as effects of tides, currents, and vertical velocity. The classifier used an optimal number of neurons in the hidden layer and a feature selection based on a genetic algorithm. The ANN method was also used to estimate the suspended sediment concentration in the future. This study provided new implications for predicting and classifying suspended sediment and zooplankton using the ADCP instrument. The proposed methodology allowed us to identify the objects with an accuracy of more than 95%.

scholarly journals Comparison of Acoustic to Optical Backscatter Continuous Measurements of Suspended Sediment Concentrations and Their Characterization in an Agriculturally Impacted River

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 981 ◽  
Author(s):  
Zacharie Sirabahenda ◽  
André St-Hilaire ◽  
Simon C. Courtenay ◽  
Michael R. van den Heuvel
Keyword(s):  
Suspended Sediment ◽  
Drainage Basin ◽  
Acoustic Doppler Current Profiler ◽  
Agricultural Watershed ◽  
Indirect Measurements ◽  
Sediment Budgets ◽  
Suspended Sediment Concentrations ◽  
Frequency Monitoring ◽  
Current Profiler ◽  
The Relationship

The increased soil loss in an agricultural watershed raises challengers for river water quality and a reliable automated monitoring for suspended sediment concentrations (SSC) is crucial to evaluate sediment budgets variation in systems. The aims of this study were (1) to test if an acoustic doppler current profiler (ADCP) would give similar results to turbidity probe measurements as a high frequency monitoring tool for suspended sediment; and (2) to analyze the relationship between sediment drivers and SSC in a typical agricultural drainage basin. The acoustic and optical backscatter sensors were used to collect SSC data during the ice-free seasons of four consecutive years in the Dunk River (PEI, Canada). The slopes of the relationships between the two SSC indirect measurements were not significantly different than 1. Correlations between SSC and hydro-meteorological variables showed that the high SSC values were more associated with the streamflow and water velocity than precipitation. This study highlighted the great potential of ADCP for the continuous monitoring of suspended sediment in an agricultural watershed. For summer periods the prevalence of clockwise hysteresis (74.1% of measured rainstorm events with SSC > 25 mg L−1) appeared related to rainstorm behaviors.

scholarly journals Estimating suspended sediment concentrations using a broadband ADCP in Mahshahr tidal channel

2011 ◽  
Vol 8 (4) ◽  
pp. 1601-1630 ◽  
Author(s):  
P. Ghaffari ◽  
J. Azizpour ◽  
M. Noranian ◽  
V. Chegini ◽  
V. Tavakoli ◽  
...  
Keyword(s):  
Time Series ◽  
Suspended Sediment ◽  
Suspended Particle ◽  
Acoustic Doppler Current Profiler ◽  
Monitoring Method ◽  
Asymmetric System ◽  
Promising Tool ◽  
Suspended Sediment Concentrations ◽  
Current Profiler ◽  
The Persian Gulf

Abstract. Data sets of Acoustic Doppler Current Profiler (ADCP) backscatter intensities (ABS) were used to evaluate suspended sediment concentrations (SSC) in the Mahshahr Channel (MC) of the Persian Gulf. Since the echo intensity is closely related to turbidity in water, the ADCP may be a promising tool to monitor the sediment transport. The low susceptibility of the acoustic backscatter to bio-fouling and the ADCP provision of current profiles as well as sediment time series makes this monitoring method more advantageous compared with the traditional methods. Time series of ADCP backscatter intensity profiles were used for improving temporal resolution of SSC estimates. Backscatter and traditional observational data were separated into two segments. The first part was utilized for calibrating the backscatter data and attributing the intensity to suspended particle concentrations and using the second part acoustic intensities were validated. Acoustic based SSC estimates are slightly underestimated in comparison with traditional water sample based SSC values, but still there is good agreement between acoustic SSC and traditional observations. Results illustrate a rather high correlation between lab based and acoustic based particles in suspension (R2 = 88 %). Additionally measurements reveal the domination of a semidiurnal ebb asymmetric system in the MC. Tidal currents provide the main energy source for particle resuspension and transport. Maximum suspended load concentrations are evident in ebb tides, while the currents strengths are enough to refloat loads from the bed. In general spring tides show higher SSC values compared with neap tides in the study area.

scholarly journals Hydrodynamics Sabang Bay and Its Influence on Near Shore Sediment Transport, Weh Island, Indonesia

Jurnal Segara ◽  
2020 ◽  
Vol 16 (2) ◽  
Author(s):  
Ulung Jantama Wisha ◽  
Ilham Ilham
Keyword(s):  
Sediment Transport ◽  
Suspended Sediment ◽  
Marine Pollution ◽  
Acoustic Doppler Current Profiler ◽  
Andaman Sea ◽  
Hydrodynamic Characteristics ◽  
Marine Tourism ◽  
Current Profiler ◽  
Near Shore ◽  
Wave Induced

Sabang Bay is one of areas of significance in Weh Island that becomes a center of marine tourism. Recently, massive urban development in coastal areas impacts on the increase of marine pollution and sedimentation issues within the bay. This study aimed to determine hydrodynamic characteristics and its influence on evoking sedimentation within the bay. Acoustic Doppler Current Profiler (ADCP) was installed within the bay for 30 days, which recorded surface elevation, waves, and sea currents. Sediment transport along the coast was determined by comparing the sediment transport and waves energy component in the form of flux equation. Tidal current speed ranging from 0-0.2 m/s moves predominantly southeastward and northwestward during flood and ebb tides, respectively. Significant wave height (Hs) ranges from 0.18-1 m with the period span of 3.5 seconds propagates toward within the bay, resulting in enhanced sedimentation within the bay caused by the wave-induced scour and turbulence. Sediment budget transported within the bay reaches 1586.18 m3/year. This proves that the sediment movement extremely occurs within the bay wherein the concentration of suspended sediment ranges from 5-35 mg/L and 2-25 mg/L during the high tidal and low tidal conditions, respectively. Scour and turbulence events are strongly induced by internal solitary waves generated from the Andaman Sea that results in increased coarse-sized sediment deposition when the flood tide takes place. While, during ebb tide, the widespread distribution of suspended sediment will occur over the bay.

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