Values Of Sediment Concentration Research Articles

Designing an explainable bio-inspired model for suspended sediment load estimation: eXtreme Gradient Boosting coupled with Marine Predators Algorithm

This study aimed to develop an accurate and reliable model for predicting suspended sediment load (SL) in river systems, which is crucial for water resource management and environmental protection. While Xtreme Gradient Boosting (XGB), a powerful ensemble machine learning (ML) model, has been employed in previous studies, the novelty of this research lies in the introduction of a hybrid approach that synergistically combines XGB with the bio-inspired Marine Predators Algorithm (XGB-MPA) to estimate SL in the Yeşilirmak River (Turkey). To this end, streamflow (Q) and sediment concentration (SC) values as well as their lag times (1 to 3 month lag times) were fed as input variables – under 9 scenarios – into ML models. A time series of datasets from March 1973 to December 2011 and January 2012 to March 2023 were used for training and testing of ML models, respectively. The superiority of the proposed model (XGB-MPA) compared to two other hybrid models, including XGB-PSO (Particle Swarm Optimization) and XGB-GWO (Grey Wolf Optimization) was also investigated. According to the results, the simultaneous application of Q and SC lag time values as inputs has led to the best SL estimates by XGB-MPA, with XGB-MPA9 (RMSE = 103.7 ton/day; NSE = 0.96) exhibiting the lowest error rates. In addition, XGB-MPA has performed better than XGB in all scenarios, with the lowest and highest reduction in RMSE being 19.3% (scenario 5) and 97.4% (scenario 1), respectively. When comparing the performance of hybrid models, the proposed XGB-MPA model has performed best with MAE, RMSE and NSE of 40.94, 103.7 and 0.96, respectively, in comparison with 816.02, 1063.74 and −2.94 for XGB-PSO and 693.16, 981.68 and −2.37 for XGB-GWO. Further research can include the use of time series of efficient variables extracted from satellite images (e.g. land cover, river morphology, etc.) as model inputs. Highlights Improvement of SL estimation by coupling MPA with XGB model Using delayed combinations of streamflow and sediment concentration as model inputs Superiority of MPA compare to PSO and GWO in SL estimation Greater variations in SHAP caused by sediment concentration compared to streamflow Further studies required on the effects of hydrological and topographical features

Suspended sediment transport generated by non-hydrostatic hydrodynamics in Northern Waters of Aceh, Indonesia

Suspended Sediment transport in the Northern Waters of Aceh is investigated in the domains between 5.4° - 5.65° N Latitude and 95.15° - 95.45° E. Therefore, this study aims to calculate the suspended sediment transport using a non-hydrostatic hydrodynamic model with an output distribution of total suspended sediment concentration. The model was run using tidal components of M2, S2, K1, O1, N2, K2, P1, Q1 and the wind every 6 h in February and August 2019 representing the North East and South West monsoons, as well as sea temperature and salinity data. The results of the model correlated with the Tide Model Driver data obtained, and the simulation results indicated the current in February 2019 is different than in August. The numerical simulation results show that the distribution of suspended sediments in Northern Waters of Aceh is driven by currents. Furthermore, the hydrodynamics and the designed model showed that the distribution value of the surface total suspended sediment concentration was lower in August than in February 2019. The verification results of the surface total suspended sediment concentration between the model and the Visible Infrared Imaging Radiometer Suite showed a good match. These results can facilitate the analysis of limited observation and remote sensing data.

Soil erosion control from trash residues at varying land slopes under simulated rainfall conditions.

Trash mulches are remarkably effective in preventing soil erosion, reducing runoff-sediment transport-erosion, and increasing infiltration. The study was carried out to observe the sediment outflow from sugar cane leaf (trash) mulch treatments at selected land slopes under simulated rainfall conditions using a rainfall simulator of size 10 m × 1.2 m × 0.5 m with the locally available soil material collected from Pantnagar. In the present study, trash mulches with different quantities were selected to observe the effect of mulching on soil loss reduction. The number of mulches was taken as 6, 8 and 10 t/ha, three rainfall intensities viz. 11, 13 and 14.65 cm/h at 0, 2 and 4% land slopes were selected. The rainfall duration was fixed (10 minutes) for every mulch treatment. The total runoff volume varied with mulch rates for constant rainfall input and land slope. The average sediment concentration (SC) and sediment outflow rate (SOR) increased with the increasing land slope. However, SC and outflow decreased with the increasing mulch rate for a fixed land slope and rainfall intensity. The SOR for no mulch-treated land was higher than trash mulch-treated lands. Mathematical relationships were developed for relating SOR, SC, land slope, and rainfall intensity for a particular mulch treatment. It was observed that SOR and average SC values correlated with rainfall intensity and land slope for each mulch treatment. The developed models' correlation coefficients were more than 90%.

Analysis Of Sediment Concentration With Flow Speed In The Primary Channel In Saddang

The decrease in channel capacity can cause sedimentation at the bottom of the channel and the condition of the channel lining is damaged so that seepage / leaks occur and buildings and sluice gates do not function properly. This study aims to analyze the concentration of sediment on the flow velocity. Measurements were carried out in the field to observe field conditions in detail related to sediment velocity and concentration. This research was carried out on the Rappang Main Channel from Upstream to Downstream of the Rappang Main Channel. The distance between upstream to downstream of the Rappang Main Channel is +- 30 Km. The distance between the upstream to the center of the research point is +- 18 Km, while the distance between the middle to the downstream channel is +- 12 Km. Velocity measurement using A.OTT propeller current meter model and sediment collection in the channel using grab sampler and van dorn tools. The results showed the effect of velocity on the value of sediment concentration in the dry season.

Sediment concentrations and transport in icebergs, Scoresby Sound, East Greenland

AbstractGlaciers erode their beds and the adjacent landscape by abrasion and plucking and entraining sediment on their way downwards driven by gravity. Ice becomes a sediment transport agent. To determine glacial transport of sediment, measurements of both the ice flux and its concentration of sediment are needed. Once glaciers reach the ocean, ice and its entrained sediment is released into the ocean by calving. Further transport takes place by icebergs. Quantification of IRD (ice‐rafted debris) fluxes, which upon ultimate deposition on the ocean floor is an important climate indicator, becomes even more complicated as icebergs topple and differentially melt while being in transport. While the volume of tidewater glacier ice released by recent calving is quite well constrained by satellite measurements, there is a lack of measurements of the concentration of sediment within the moving ice. Here, we describe a method to collect samples of ice from icebergs systematically for the first time in Greenland together with a strategy to obtain representative samples. Our method is tested in Scoresby Sound, East Greenland in order to describe the transport of sediment into the fjord system related to calving from known glacial source areas. Our data clearly demonstrate that biased and sparse sampling potentially produces unrealistic values of sediment concentrations. Seventy‐two samples from 24 icebergs had an average concentration of sediment of 35.5 g/L of ice with a standard deviation of 97%, between the 24 individual icebergs. The origin of the sediment is related to specific source areas. Based on the samples, we present an estimate of the annual transport of sediment out of Scoresby Sound related to calving ~100 (0.3–200) million t year−1. Finally, we discuss the uncertainties of our estimate.

Combined effects of waves and tides on bottom sediment resuspension in the southern Yellow Sea

A calibrated, coupled model (COAWST) of the Bohai and Yellow Seas was employed to examine the contributions of waves and tides to the sediment transport, and to understand the dynamic factors controlling bottom sediment resuspension around the Shandong Peninsula. The numerical results, which were consistent with the in-situ observations, illustrated two events with large values of suspended sediment concentration (SSC). The two events had similar wave heights, but SSC during the second event was more than twice that of the first one. Numerical experiments indicated that the large values of SSC east of the Shandong Peninsula were mainly ascribed to local resuspension, and that waves played a primary role in sediment resuspension for both high SSC events. The differences in SSC and bottom shear stress between the two events were mainly due to differences in wave period, representing about 65% of the total difference, and the non-linear interactions of wave and currents played a secondary role. Therefore, wave period is an important factor along with wave amplitude in the contribution of waves to sediment resuspension in this region. The combined actions of waves and currents dynamics dominate the sediment resuspension rather than either factor in isolation. Due to sheltering effect by the Shandong Peninsula, the wave effect on sediment resuspension was less to the south of the Peninsula than that to the north and east. In addition, the Shandong Coastal Current was enhanced by the northerly wind leading to more sediment transport southward along the coast of Shandong Peninsula, but this has small effect on the difference of suspended sediment concentration between two storm events.

Approach to sediment monitoring in Hydro Power Plant

The presence of mineral sediments in water led to significant erosion damage to a power plant in the Chilean Andes. The plant is operated by Enel and is equipped with three vertical Francis power units, with approximately 25 MW each operating under a net head of around 120 m. The overall machine condition with reported significant damage on the turbine caused by erosion led to a modernization project with runner replacement and output and efficiency increase. In order to ensure a proper sediment measurement and quantification during the turbine operation, Voith developed, supplied and installed a sediment monitoring system in power unit #01. The monitoring system, developed using the OnCare.Health Hydro platform, applies optical sensors installed directly in the spiral case inlet section to measure the water turbidity. Other operational parameters are recorded, processed and stored together in the same database. Two optical sensors were installed in the spiral case inlet section and provide turbidity readings. The first one is positioned directly flush to the flow. The second one is located in a sampling pipe that collects water from four different points of the same cross section. An automatic water sampler installed in the sampling pipe collects water periodically, which is sent to a laboratory for particle analysis. The laboratory results allow an identification of important parameters such as sediments concentration, particle sizes and materials that are used for correlation with the indicated turbidities. The main data analysis shows that the power unit operated most of the time close to the rated condition. A comparison between turbidities indicated by both sensors shows an offset, probably associated to the particles distribution along the cross section. A system calibration process successfully correlated suspended sediment concentration and turbidity values to allow online indications of the sediment concentration. The system has been operating for almost two years in a close cooperation with the engineering teams of the plant owner and system provider. Main results and system findings for this application will be presented and discussed in this paper.

Exploring the association between landslides and fluvial suspended sediment in a semi-arid basin in central Chile

The systematic monitoring of landslides is an essential input for their characterization and subsequent reduction of their risk. Along the western subtropical Andes, field monitoring is scarce, so alternative methods that can improve the monitoring are valuable. In this work, the capacity of fluvial suspended sediment to detect the occurrence of landslides in a basin was explored, emphasizing how the relationship varies depending on the hydro-sedimentological variable, the triggering causal factor and the landslide type. The values of suspended sediment concentration (SSC), water discharge (Q) and specific suspended sediment yield (SSY) associated with mass movements were collected from a fluviometric station, as well as maxima of these variables that were not associated with landslides. With these data, different General Linear Models were constructed considering possible non-linear effects of the covariates. Flow-type landslides triggered by rain (most of the events) are correctly predicted, especially using the linear effects of SSC and Q. For this mass movement type the prediction is suitable even for events triggered by isolated, short-lived rains, which are difficult to detect in mountainous areas with meteorological devices.

The Influence of Vertical Velocity Distribution on the Calculation of Suspended Sediment Concentration

Based on the advection‐diffusion equation of suspended sediment, a general formula of vertical distribution of suspended sediment concentration was derived by considering the influence of vertical velocity. The new formula was tested against over 3000 sets of field data and obtained a reasonable agreement. Comparing with the Rouse equation of concentration, the accuracy of the new formula increases significantly, and the shortcoming of the underestimation of the Rouse profile in practical application is revised. Through the analysis of the new formula with different vertical time‐averaged velocity coefficients m, it was found that vertical velocity does have an impact on the accurate estimation of sediment concentration, and the extent of which is related to the value of sediment concentration. Utilizing the regression analysis, it was found the vertical time‐averaged velocity coefficient m increases with the height above the bed.

NUMERICAL STUDY ON SUSPENDED SEDIMENT TRANSPORT UNDER THE EFFECT OF WATER TEMPERATURE IN RESERVOIRS/LAKES

Water resources management is one of the most important issues and challenges in the world. This management may be in the form of quality management or quantitative management of water resources. Quality management of water resources is of great importance. A major problem in this case is how the input flow (for example a river) will behave when water flows to a dam reservoir or lake. Distribution of the input stream to the reservoir/lake depends on important parameters such as inflow discharge, input depth, situation and type of the reservoir outlet, type of inlet sediment , sediment concentration of inflow current and reservoir/lake , and etc. Therefore, this effect of each of the mentioned parameters on the distribution in the reservoir or lake should be examined. An important parameter that has not yet been studied is the effect of temperature of the inflow current's and the reservoir/lake's water on the distribution. For this purpose, the FLOW3D computational fluid dynamics code was selected in this study. The effect of water temperature and concentration of suspended sediment on distribution in reservoirs/lakes is considered. Several simulations with different water temperature and suspended sediment concentration values were done. Results are shown and compared each other. The results indicate the high effect of water temperature on distribution of sediments.

Coupled modeling of bed evolution and bank deformation in the braided reach of the Lower Yellow River

<p indent=0mm>Floodplains on both sides of the braided reach in Lower Yellow River (LYR) are extremely wide, accounting for 80% of the total channel area, and large channel deformation occurs during the flood season in this reach. Thus, bed evolution and riverbank deformation are typical characteristics of channel evolution in the braided reach of LYR. To calculate riverbed evolution and riverbank deformation, a one-dimensional coupled model, which includes three modules for hydrodynamics, sediment dynamics, and bed evolution, bank erosion, and accretion, is proposed. The proposed model was used to simulate the longitudinal and lateral deformation in the braided reach of LYR in 2006 and 2018 to conduct detailed processes of model calibration and verification. Results indicate the following. (1) The proposed model can accurately simulate flow and sediment transport processes. The Nash-Sutcliffe efficiency coefficient (NSE) between calculated and measured values of water discharges, water levels, and sediment concentrations was above 0.6, with a maximum value of 0.97. (2) The riverbank accretion and erosion widths were roughly calculated, and the relative errors between the calculated and measured reach-scale riverbank widths were less than 1.5%. (3) Analysis of the effect of riverbank deformation on longitudinal deformation revealed that riverbank accretion and erosion calculation modules played an important role in the calculation of flow, sediment transport, and riverbed evolution in the braided reach of LYR.

Influence of Sediment load on Stable Sand Bed Channels.(Dept.C)

The main objective of this research work is study to what extent sediment load can affect the sand bed channel geometry i.e. mean width, water depth and bed slope. It was found in this study, the bed slope increased regularly with the increasing value of sediment concentration. Statistical analysis was performed to get the relationship between bed slope and sediment concentration at different values of discharges, for canals having median particle size varied between 0.05 mm and 0.5 mm. Both water depth and mean width could decrease with the increasing value of sediment concentration for canals having median particle size ≤ 0.4 mm.

Mutual influences between synchronous measurement of salinity and sediment concentration

Accurate synchronous measurement of salinity and sediment concentration has always been a concern for estuarine researchers. Considering salinity measurement based on electrical conductivity and sediment concentration measurement based on optical backscatter are still the most widely used measurement methods, a set of salinity measuring instrument and a set of fibre optic sediment concentration measuring instrument are designed and developed in the paper. The mutual influences between synchronous measurement of salinity and sediment concentration are experimentally studied. The experimental results show that the presence of sediment decreases the measured value of salinity, and the presence of salinity decreases the measured value of sediment concentration. The correlation relations and the corresponding correction formulae are determined experimentally. The proposed method improves synchronous measurement accuracy of salinity and sediment concentration, which is of great significance for their accurate measurement in estuarine coastal waters.

Kajian Distribusi Konsentrasi Sedimen Suspensi Menggunakan TSS Meter pada Sungai Brantas di Desa Pendem Kota Batu

The river is the site of sedimentation, which sediment is sourced from erosion and erosion of the soil layer on the slopes of the river. This sedimentation can decrease water utilization because it results in reduced capacity and water quality in rivers, irrigation channels, reservoirs, and others. So research is needed to find out the distribution of suspension sediment concentrations to plan the steps in the management of water along the river. The method used in solving this problem is to use portable TSS Meter, Partech 740 structure to facilitate the collection of the concentration of suspension sediment in the field easily at any given height. This study was conducted ten (10) times sampled at different times and days using portable TSS Meter aids to determine the distribution value of suspension sediment concentration at each flow depth. In this study, there is a relationship between flow discharge (Qw) and suspension sediment discharge (Qs) with the equation Qs = 1.1071.Qw2.3488, and there is a relationship between flow discharge and the average suspension sediment concentration with the equation C = 12.813.Qw1.3488, and the last obtained magnitude of rouse exponent factor is in the range of 0.01435 – 0.054064.

3D numerical modelling of asynchronous propagation characteristics of flood and sediment peaks in three gorges reservoir

The asynchronous propagation characteristics of flood and sediment peaks downstream (i.e., sediment peak lagging behind flood peak) are crucial for the operation of sediment peak release to reduce the sedimentation of the Three Gorges Reservoir (TGR). In the flood season of 2013, the sediment peak regulation was conducted in the TGR, based on the asynchronous propagation characteristics of flood and sediment peaks, and promising results were achieved towards reducing the reservoir sedimentation. In this study, the processes of flood propagation and sediment transport over a stretch of 280 km, upstream of the TGR on the Yangtze River were studied through a three-dimensional (3D) semi-implicit cross-scale hydroscience integrated system model (SCHISM), focussing on the asynchronous propagation characteristics of flood and sediment peaks downstream. It was demonstrated that firstly, the model efficiently and accurately reproduced the processes of flood propagation and sediment transport during the 2013 flood season compared with the measured results. The sensitivity analysis showed that the horizontal grid used in the numerical modelling had a greater influence on the model results than the vertical grid. The Manning coefficient was not sensitive to flood peaks propagation with a large flow discharge. Next, the validated model was adopted to investigate the asynchronous propagation characteristics of the flood and sediment peaks under different TGR operational scenarios. The results indicated that the impounded level ahead of the Three Gorges Dam (TGD) had an insignificant influence on the occurrence time and magnitude of the flood peak, but had a significant influence on the occurrence time and magnitude of the sediment peak. The time of sediment peak lagging behind flood peak increases as the impounded level in the TGR increased. The peak value of sediment concentration gradually decreased owing to the sediment deposition. The research results could provide a scientific basis for further optimising the sediment peak regulation, and the 3D numerical model could provide a reliable real-time tool to predict the arrival time of the flood and sediment peaks in the TGR.

Sediment diffusion coefficient model for predicting the vertical distribution of suspended sediment concentration in uniform open-channel flows

This paper presents a theoretical model for predicting the vertical distribution of suspended sediment concentrations in open-channel flows. The model developed uses a new sediment diffusivity coefficient obtained by the application of the Itakura and Kishi correction method to the Kerssens sediment diffusivity profile. The new coefficient is calculated using composite operators applied to the Rouse sediment diffusivity profile. The diffusivity profile proposed increases as a parabolic profile from zero at the bottom to a maximum value in the lower part of the flow, and then decreases slowly towards the water surface without reaching zero. The maximal value is calculated at a level between 20 and 30% of the total water depth as explained previously by Coleman. Based on this diffusivity profile, a theoretical formulation for computing sediment concentration is derived analytically, using the well-known convection–diffusion equation. We compare results from the proposed model with experimental measurements and existing theoretical models, obtained by previous researchers, in order to evaluate the applicability of the present model to predict particle concentration profiles in open-channel flows. The computed values of sediment concentrations are in good agreement with the experimental data reported in the literature.

Application of newly developed ensemble machine learning models for daily suspended sediment load prediction and related uncertainty analysis

ABSTRACT Ensemble machine learning models have been widely used in hydro-systems modeling as robust prediction tools that combine multiple decision trees. In this study, three newly developed ensemble machine learning models, namely gradient boost regression (GBR), AdaBoost regression (ABR) and random forest regression (RFR) are proposed for prediction of suspended sediment load (SSL), and their prediction performance and related uncertainty are assessed. The SSL of the Mississippi River, which is one of the major world rivers and is significantly affected by sedimentation, is predicted based on daily values of river discharge (Q) and suspended sediment concentration (SSC). Based on performance metrics and visualization, the RFR model shows a slight lead in prediction performance. The uncertainty analysis also indicates that the input variable combination has more impact on the obtained predictions than the model structure selection.

Hydrological Modelling of Sediment Yield of Agr0 -Forestry Watershed

For this analysis, the Manot sub-basin region of Upper Narmada Basin located in Madhya Pradesh, India, is designated for estimation of runoff, sediment load, sediment concentration and sediment yield using SWAT. The model was implemented during 1989 and 2008. NBSSLUP soil data, Digital Elevation Model (DEM), slope, Land use Ground cover (LULC) and climate records of temperature and rainfall were used as inputs for the Manot Gauge Station. The forecasted model discharge was estimated statistically and compared the real daily flow data from 1989 to 2008, which corresponds to a major number. The R2 value (coefficient of determination) for discharge, sediment concentration, sediment load and sediment yield values for the period 1989 to 2008 were found to be 0.95, 0.94, 0.96 and 0.96 respectively. RMSE for discharge, sediment concentration and sediment yield were found to be 0.32, 0.27 and 0.17, respectively. The expected sediment load at the Manot Gauge Station for the duration (1989–2008) is 6670918 tons per year and the observed sediment load is 6255565 tons per year. Simulated sediment load and measured sediment load at the Manot Gauge Station are 14.13 tons / year / hectare and 15.02 tons / year / hectare, respectively. Predicted sediment concentrations and measured sediment concentrations at the Manot gauging station were found to be 8.81 ppm and 7.46 ppm, respectively. Similarly, the expected and observed Sediment Yield was 1.513 mm and 1.704 mm respectively.

Evaluación de los procesos superficiales de escorrentía en cárcavas originadas en olivares convencionales. Un apartado a tener en cuenta en la planificación territorial

Se analiza la respuesta hidrologica de una carcava efimera frente a un evento de lluvia equivalente de frecuencia “ordinaria” (≈1 ano) a partir de una simulacion de escorrentia en una cuenca experimental con olivar en Puente Genil, Cordoba (Espana). Mil litros de agua fueron bombeados durante 10 minutos y la descarga total, la velocidad superficial de avance de frente de flujo, la concentracion de sedimentos y los cambios morfologicos en el perfil transversal fueron calculados. Los resultados mostraron elevadas diferencias entre las tasas de escorrentia de hasta un 17% entre las condiciones “secas” y “humedas”. La concentracion de sedimentos instantanea llego a alcanzar valores de hasta 40 g l-1. Se concluye que las carcavas en olivares convencionales son capaces de registrar elevadas tasas de erosion y escorrentia, particularmente bajo condiciones de mayor humedad. Se requiere mas informacion y atencion a las medidas de control sobre la erosion por el flujo concentrado de la escorrentia en la planificacion agricola.

Laboratory measurements of the fall velocity of fine sediment in an estuarine environment

The study of the fall velocity variation of fine sediment in estuarine areas plays an important role in determining how various factors affect the flocculation process. Previous experimental studies have focused solely on the relation between the median fall velocity and influencing factors, while in the current study, the variation of the fall velocity in quiescent water also was examined. The experimental results showed that the vertical distribution of sediment concentration was more uneven, and larger variations occurred earlier during the settling process under higher salinity and/or sediment concentration conditions. The fall velocity initially increased then decreased over time, peaking at ∼20 min after settling began, and stabilizing at a value similar to that in freshwater, regardless of the initial sediment concentration and salinity combinations. Along the water depth, the fall velocity increased monotonically with a gradually decreasing gradient. The median fall velocity increased then decreased with increased salinity. The salinity at which the peak fall velocity occurred depended on the initial sediment concentration. The relation between the median fall velocity and initial sediment concentration displayed an obvious two-stage pattern (i.e., accelerated flocculation and decelerated, hindered settling) at higher salinities; whereas the maximum median fall velocity was observed at two consecutive sediment concentration values under lower salinity conditions. Finally, an empirical equation estimating the median fall velocity of cohesive fine sediment was formulated, incorporating the effects of both salinity and sediment concentration.