Indirect Estimation of Flow and Suspended-sediment Concentration and Load in Small Mountain Streams: an Exploratory Study in Ribeira Seca Stream, Madeira Island

Suspended Sediments ◽

Sediment Concentration ◽

Measurement Campaign ◽

Indirect Determination ◽

Madeira Island ◽

The North

The aim of this study was to assess the applicability of indirect techniques for streamflow and suspended sediment concentration estimation and their use in the calculation of suspended sediment transport rate in the small mountain watersheds of Madeira Island, Portugal. Emphasis was given to the application of salt dilution gauging to the indirect determination of the flow rate and the use of water turbidity data to estimate the concentration of suspended sediments. The field and laboratory work carried out are briefly described, and the main experimental results and the field data from the short measurement campaign performed in the Ribeira Seca stream in Faial, on the north side of the island, are presented and discussed. Whilst the measurement campaign carried out was temporally and spatially limited, it was pioneering for Madeira and allowed to verify the applicability of the indirect hydrometric and sedimentometric techniques used in this exploratory study.

Transport Mechanism of Suspended Sediments and Migration Trends of Sediments in the Central Hangzhou Bay

Water ◽

10.3390/w12082189 ◽

2020 ◽

Vol 12 (8) ◽

pp. 2189

Author(s):

Zekun Song ◽

Weiyong Shi ◽

Junbiao Zhang ◽

Hao Hu ◽

Feng Zhang ◽

...

Keyword(s):

Sediment Transport ◽

Suspended Sediment ◽

Suspended Sediments ◽

Sediment Concentration ◽

Hangzhou Bay ◽

The South ◽

Transport Mode ◽

Tidal Pumping ◽

The North

Based on the 2013 field survey data of hydrology, suspended sediments and bottom sediments in the Central Hangzhou Bay, this paper explores the dynamic mechanism of suspended sediments in Hangzhou Bay by employing material flux decomposition. Meanwhile, the migration trends of bed sediments are also investigated by analyzing grain size trends. The results show that during an ebb or flood tide, the hydrograph of suspended sediment concentration of Hangzhou Bay is dominated by an M shape (bimodal), which is attributed primarily to the generation of a soft mud layer and a separate fluid mud layer. Laterally, the distribution of suspended sediment concentration is high in the south and low in the north. From a macroscopic perspective, the net sediment transport in the study area displays a “north-landward and south-seaward” trend, presenting a “C”-shaped transport mode. That is, the sediments are transported from the bay mouth to the bay head on the north side and from the bay head to the bay mouth on the south side. The sediment transports by advection and tidal pumping are predominant, while the sediment transport by vertical circulation makes little contribution to the total sediment transport. Moreover, the sediment transport in the center of the reach area is dominated by advection, whereas that near both sides of the banks is controlled by tidal pumping. The asymmetry of the tides, i.e., flood-dominance in the north and ebb-dominance in the south, is the primary cause of the dynamic mechanism for the overall “C”-shaped transport mode in Hangzhou Bay. Additionally, coupled with the narrow-head wide-mouth geomorphology, Hangzhou Bay remains evolving by south shore silting and north shore scouring.

Curvas-chave de descargas de sedimentos em suspensão no Baixo São Francisco

Revista Brasileira de Geografia Física ◽

10.26848/rbgf.v13.3.p1248-1262 ◽

2020 ◽

Vol 13 (3) ◽

pp. 1248 ◽

Cited By ~ 1

Author(s):

Solange Cavalcanti de Melo ◽

José Coelho de Araújo Filho ◽

Renata Maria Caminha Mendes de Oliveira Carvalho

Keyword(s):

Suspended Sediment ◽

Suspended Sediments ◽

Sediment Concentration ◽

Gradual Reduction ◽

Sao Francisco River ◽

Sediment Loads ◽

São Francisco River ◽

Historical Series ◽

Suspended Sediment Concentrations

RESUMOO conhecimento da análise quantitativa das concentrações de sedimentos em suspensão transportados pelo rio São Francisco bem como sua relação com as vazões é de muita importância, pois pode auxiliar na identificação dos efeitos da intervenção humana e ou ocasionados pelas condições naturais da região. As regiões a jusante dos barramentos no rio São Francisco apresentam como principal consequência a regularização das vazões e a diminuição das concentrações de sedimentos. O objetivo da pesquisa foi determinar as curvas-chave de sedimentos em suspensão (CCS) nas estações fluviométricas instaladas no Baixo São Francisco (BSF) após a barragem de Xingó. Para o estabelecimento dessas curvas foram utilizados dados de vazão e concentração de sedimentos em suspensão, obtidos do sistema Hidroweb no site da Agência Nacional da Água (ANA) no período de 1999 a 2018. Foram obtidas CCS para todo o trecho do BSF as quais apresentaram bons coeficientes de determinação. Na análise dos dados também foi possível perceber que nos últimos anos, desde 2013 houve redução gradativa das vazões disponibilizadas na barragem de Xingó. Consequentemente, houve também a redução gradativa das cargas de sedimentos em suspensão geradas nas estações de Piranhas, Traipu e Propriá, ou seja, os menores valores já registrados no BSF correspondendo as menores séries históricas tanto de vazão como de sedimentos em suspensão. Keys curves of sediment discharges in suspension in the Lower São Francisco A B S T R A C TThe knowledge of the quantitative analysis of suspended sediment concentrations carried by the São Francisco River as well as its relation with the flows is of great importance, since it can help in the identification of the effects of human intervention and/or caused by the natural conditions of the region. In the downstream regions of the São Francisco riverbanks, the main consequence was the regularization of flow rates and the reduction of sediment concentrations. The objective of the research was to determine the key curves of suspended sediments (CCS) at the fluviometric stations installed in the lower São Francisco river after Xingó dam. For the evaluation, flow data and suspended sediment concentration were used. These data were obtained from the Hidroweb system on the website of the National Water Agency (ANA) from 1999 to 2018. CCS were plotted for all stretches and presented good coefficients of determination (R2). Based on the analysis of the data it was also possible to notice that in recent years, since 2013 there has been a gradual reduction of the flows available in the Xingó dam. Consequently, there was also a gradual reduction of suspended sediment loads generated at the Piranhas, Traipu and Propriá stations, that is, the lowest values already recorded in lower São Francisco, corresponding to the lower historical series of both discharge and suspended sediments.Keywords: dam, flow, sediments

Comparative Assessment of Fluvial Suspended Sediment Concentration Analysis Methods

Water ◽

10.3390/w12030873 ◽

2020 ◽

Vol 12 (3) ◽

pp. 873 ◽

Cited By ~ 1

Author(s):

Flóra Pomázi ◽

Sándor Baranya

Keyword(s):

Suspended Sediment ◽

Acoustic Doppler Current Profiler ◽

Sediment Concentration ◽

Comparative Assessment ◽

Danube River ◽

Indirect Methods ◽

Analysis Methods ◽

Sediment Monitoring

The monitoring of fluvial suspended sediment transport plays an important role in the assessment of morphological processes, river habitats, or many social activities associated with river management. However, establishing and operating a well-functioning sediment monitoring system requires the involvement of advanced indirect methods. This study investigates the advantages and limitations of optical and acoustic devices, to quantify the uncertainties and provide a comprehensive comparative assessment of the investigated indirect methods. The novelty of this study, compared to previous ones, is that four different indirect techniques are parallel tested, i.e., the laser diffraction based LISST-Portable|XR, an infrared based optical instrument, the VELP TB1 turbidimeter, the acoustic based LISST-ABS (Acoustical Backscatter Sensor) sensor, and a 1200 kHz Teledyne RD Instruments Acoustic Doppler Current Profiler (ADCP). The calibration of all the indirect methods was performed based on more than 1000 samples taken from the Hungarian section of the Danube River within a wide suspended sediment concentration range. Implementing a comparative assessment of the different sediment analysis methods, a qualitative and quantitative characterisation of the applicability is provided. Furthermore, a proposal for an optimised sediment monitoring methodology is also suggested.

Dynamics of Suspended Sediments Related to Fine Particles in Lower Mekong River

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.446-447.1528 ◽

2013 ◽

Vol 446-447 ◽

pp. 1528-1533

Author(s):

Sarunya Promkotra

Keyword(s):

Shear Stress ◽

Flow Velocity ◽

Suspended Sediment ◽

Fine Particles ◽

Suspended Sediments ◽

Sediment Concentration ◽

Mekong River ◽

Fall Velocity ◽

Stream Discharge

Analytical results are considered the factors of suspended sediment concentration, fall velocity, dimensionless shear stress, transportation rate and stream discharge. As a result of suspended sediments of Loei, Huang and Mekong River, fine particles account for the applicability in sediment deposits. Floating suspended sediments explicit more clay minerals than suspended sediments. Suspended sediment concentration (SSC) in the estuarine of Loei River and Huang River are moderately less than Mekong River. Flow directions of the interconnected rivers to the mainstream-Mekong River lead to the quantity of SSC. Sediment concentrations attain to the dynamic response. Dimensionless shear stress relates to shear velocity, geometry and grain size of particles, and difference of flow velocity. This shear stress is directly comparative to flow velocity and clay mineral concentrations. The transport rate involves in the flow velocity, SSC and depth of the river. Moreover, stream discharge can be presumed by the geometry of the river and topography of sampling locations.

On the Suspended Sediment Concentration Profile

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.212-213.20 ◽

2012 ◽

Vol 212-213 ◽

pp. 20-24 ◽

Cited By ~ 1

Author(s):

Chen Cheng ◽

Zhi Yao Song ◽

Yi Gang Wang ◽

Jin Shan Zhang

Keyword(s):

Boundary Condition ◽

Suspended Sediment ◽

Order Approximation ◽

Sediment Concentration ◽

Surface Boundary ◽

Sediment Diffusion Coefficient ◽

Surface Boundary Condition ◽

First Order Approximation

After analyzing the surface-boundary condition of suspended sediment concentration (SSC), Cheng et al.[7] further improved the sediment diffusion coefficient which was proposed by Bose and Dey[6]. Then an improved Rouse law (IRL) was developed. This equation, which has a similar form as Rouse law, not only overcomes the zero concentration at the free surface, but also behaves generally better than Rouse law and van Rijn equation over the whole water depth in the verification analysis. In this paper, the surface-boundary condition of SSC is further analyzed. It is elucidated that IRL satisfies the surface-boundary condition more reasonably than Rouse law. In addition, a first-order approximation of IRL is developed. From this approximation, we can easily get the explicit expression of the depth-averaged SSC without any implicit integrals to be solved numerically or by the help of a chart. This is very useful in the further study of non-equilibrium suspended sediment transport (SST).

Surf Zone Turbulence and Suspended Sediment Dynamics—A Review

Journal of Marine Science and Engineering ◽

10.3390/jmse9111300 ◽

2021 ◽

Vol 9 (11) ◽

pp. 1300

Author(s):

Troels Aagaard ◽

Joost Brinkkemper ◽

Drude F. Christensen ◽

Michael G. Hughes ◽

Gerben Ruessink

Keyword(s):

Sediment Transport ◽

Suspended Sediment ◽

Surf Zone ◽

Sediment Concentration ◽

Sandy Beaches ◽

Velocity Signal ◽

Wave Phase ◽

Turbulence Production

The existence of sandy beaches relies on the onshore transport of sand by waves during post-storm conditions. Most operational sediment transport models employ wave-averaged terms, and/or the instantaneous cross-shore velocity signal, but the models often fail in predictions of the onshore-directed transport rates. An important reason is that they rarely consider the phase relationships between wave orbital velocity and the suspended sediment concentration. This relationship depends on the intra-wave structure of the bed shear stress and hence on the timing and magnitude of turbulence production in the water column. This paper provides an up-to-date review of recent experimental advances on intra-wave turbulence characteristics, sediment mobilization, and suspended sediment transport in laboratory and natural surf zones. Experimental results generally show that peaks in the suspended sediment concentration are shifted forward on the wave phase with increasing turbulence levels and instantaneous near-bed sediment concentration scales with instantaneous turbulent kinetic energy. The magnitude and intra-wave phase of turbulence production and sediment concentration are shown to depend on wave (breaker) type, seabed configuration, and relative wave height, which opens up the possibility of more robust predictions of transport rates for different wave and beach conditions.

Sampling strategies to estimate suspended sediment concentration for turbidimeter calibration

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v21n12p884-889 ◽

2017 ◽

Vol 21 (12) ◽

pp. 884-889 ◽

Cited By ~ 2

Author(s):

Leandro Dalbianco ◽

Rafael Ramon ◽

Claudia A. P. de Barros ◽

Jean P. G. Minella ◽

Gustavo H. Merten ◽

...

Keyword(s):

Suspended Sediment ◽

Suspended Sediments ◽

Sediment Concentration ◽

Rainfall Event ◽

Sampling Strategies ◽

Southern Brazil ◽

Rainfall Events ◽

Insufficient Amount ◽

Indirect Relationship

ABSTRACT The influx of sediments carried by rivers can be measured continuously using a turbidimeter through the indirect relationship between turbidity and suspended sediment concentration (SSC). However, this process is dependent on obtaining water samples with suspended sediments to calibrate the turbidimeter. Sampling can be carried out through different methods, resulting in errors and uncertainties in estimating the SSC. Four different possibilities for the composition of the calibration curve were tested in order to evaluate the effectiveness of the turbidimeter calibration for different sampling strategies. The study was conducted in 2012 and 2013 in two catchments in southern Brazil that had a strong sediment yield impact. The results indicate that sampling during rainfall events generate a significant and representative SSC for the turbidimeter calibration. The use of an integrating sampler for synthetic samples provides an effective calibration, but overestimates SSC compared to calibration from rainfall event sampling. The samples collected at fixed intervals - weekly and daily - generated an insufficient amount of data and are not representative of real sediment concentrations of the catchments.

Development of a method for suspended sediment transport monitoring by means of ADCP measurements

E3S Web of Conferences ◽

10.1051/e3sconf/20184005016 ◽

2018 ◽

Vol 40 ◽

pp. 05016

Author(s):

Rui Aleixo ◽

Massimo Guerrero ◽

Nils Ruther ◽

Siri Stokseth

Keyword(s):

Suspended Sediment ◽

Sediment Concentration ◽

Ecological Processes ◽

Critical Data ◽

Adcp Measurements ◽

Remote Measurements ◽

Water Courses ◽

The Relationship

Monitoring stations in rivers and water courses are an important mean to obtain critical data about the different variables that play a role in the hydrodynamics and ecological processes. Measuring suspended sediment concentration often requires the displacement of equipment and manpower to the field. This is often expensive and not practical, in particular during severe weather and flow conditions. A method to determine the suspended sediment concentration as a result of ADCP remote measurements is here presented. This method relies on the relationship between the attenuation to backscatter ratio and the normalized attenuation coefficient. To test this method, data from a field monitoring station in Kokel, on the banks of the Devoll river in Albania, is used.

Proceedings of International Conference "Managinag risks to coastal regions and communities in a changinag world" (EMECS'11 - SeaCoasts XXVI) ◽

METHODOLOGICAL ASPECTS OF THE SUSPENDED SEDIMENT CONCENTRATION MEASUREMENT IN THE COASTAL ZONE

10.21610/conferencearticle_58b4315f3011c ◽

2017 ◽

Author(s):

Рубен Косян ◽

Ruben Kosyan ◽

Marina Krylenko ◽

Marina Krylenko

Keyword(s):

Suspended Sediment ◽

Coastal Zone ◽

Field Experiments ◽

Rotation Axis ◽

Sediment Concentration ◽

The North ◽

Wave Channel ◽

Mediterranean And Black Seas ◽

Methodological Aspects

Results of the suspended sediment concentration study in the coastal zone on the basis of field and laboratory experiments are analyzed. Data from field experiments, performed in the coastal zone of the North, Mediterranean and Black seas, are used. The laboratory researches were fulfilled in the Big Wave Channel of the Hannover University. It is shown that to increase the accuracy of measurement it is necessary to take into account the convective mechanism of the sediment suspension, as well as the size, the direction of the rotation axis and other parameters of the turbulent vortices transporting sand sediments. The presented information will help to improve the quality of field data collection.

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

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/944/1/012014 ◽

2021 ◽

Vol 944 (1) ◽

pp. 012014

Author(s):

A Dwinovantyo ◽

S Solikin ◽

H M Manik ◽

T Prartono ◽

Susilohadi

Keyword(s):

Suspended Sediment ◽

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%.