Analysis Of Sediment Transport Research Articles

Tidal Current with Sediment Transport Analysis and Wind Turbine Foundation Pile Scour Trend Studies on the Central Bohai Sea

Tidal Current with Sediment Transport Analysis and Wind Turbine Foundation Pile Scour Trend Studies on the Central Bohai Sea

Development of an acceleration method for sediment transport analysis with suspended load and bedload in an integrated river channel and coastal region

ABSTRACT To analyze sediment dynamics in estuaries during floods, a method capable of three-dimensional flows for high-resolution calculations is essential. However, such calculations are computationally intensive for midium to long term periods. We developed a high-speed calculation method for temporal variations in river bed topography and sediment discharge from river basins based on the average component acceleration (ACA) method by shortening the duration of floods. In the ACA method, the local components remained unchanged, and the temporal variation in the average components was amplified. This study developed the ACA method to calculate sediment transport, including bedload and suspended load, around an estuary. The ACA method enabled five times faster than the analysis of riverbed variations and the amount of sediment discharge compared to the conventiola non-accelerated analysis. It also accurately captured the widening of the estuarine sandbar opening during a flood demonstrating its utility for medium- to long-term riverbed-change analysisand its advantage over the other acceleration methods.

Implementing Superresolution of Nonstationary Tides with Wavelets: An Introduction to CWT_Multi

Abstract Tides are often nonstationary due to nonastronomical influences. Investigating variable tidal properties implies a trade-off between separating adjacent frequencies (using long analysis windows) and resolving their time variations (short analysis windows). Previous continuous wavelet transform (CWT) tidal methods resolved tidal species. Here, we present CWT_Multi, a MATLAB code that 1) uses CWT linearity (via the “response coefficient method”) to implement superresolution, i.e., resolving tidal constituents beyond the Rayleigh criterion; 2) provides a Munk–Hasselmann constituent selection criterion appropriate for superresolution; and 3) introduces an objective, time-variable form of inference (“dynamic inference”) based on time-varying data properties. CWT_Multi resolves tidal species on time scales of days, and multiple constituents per species with fortnightly filters. It outputs astronomical phase lags and admittances, analyzes multiple records, and provides power spectra of the signal(s), residual(s), and reconstruction(s); confidence limits; and signal-to-noise ratios. Artificial data and water levels from the Lower Columbia River Estuary (LCRE) and San Francisco Bay Delta (SFBD) are used to test CWT_Multi and compare it to harmonic analysis programs NS_Tide and UTide. CWT_Multi provides superior reconstruction, detiding, dynamic analysis utility, and time resolution of constituents (but with broader confidence limits). Dynamic inference resolves closely spaced constituents (like K1, S1, and P1) on fortnightly time scales, quantifying impacts of diel power peaking (with a 24-h period, like S1) on water levels in the LCRE. CWT_Multi also helps quantify the impacts of high flows and a salt barrier closing on tidal properties in the SFBD. On the other hand, CWT_Multi does not excel at prediction, and results depend on analysis details, as for any method applied to nonstationary data. Significance Statement Ocean tides, especially in coastal and estuarine systems, are often nonstationary, in the sense that the mean and standard deviation of tidal properties vary over time, usually in response to some nontidal process. We introduce here a MATLAB code, CWT_Multi, that uses wavelet transforms to resolve both tidal species and constituents on time scales from a few days to months. Our code accommodates multiple scalar time series and has typical tidal analysis features like constituent selection and inference, plus two forms of uncertainty analyses. It is flexible, allowing the user to adapt analysis properties to diverse datasets. CWT_Multi is applicable to many problems involving time-variable tides, including sea level rise, compound flooding, sediment transport, and wetland habitat analyses. Application to vector data is a straightforward extension, but further development of our uncertainty analysis is merited. Because nonstationary tidal analysis is rapidly advancing, we also define the features of a “well-formed” analysis code.

Assessing the possible influence of human activities on sediment transport in the Saskatchewan River and its delta

Sediment transport is a complex, multi-dimensional process. With the advancement in computing power and sophistication of computer applications over recent decades, it has become possible to conduct detailed analysis and simulations of soil erosion and sediment transport. The primary objective of this study was to examine and predict the potential influence of human activities on sediment transport. This was achieved by analyzing sediment transport in the Saskatchewan River beneath the E.B. Campbell Dam and in the Saskatchewan River Delta. The Hydrologic Engineering Center's-River Analysis System (HEC-RAS) was deployed to ascertain the sediment transport capacity and estimate erosion, sedimentation, and riverbed changes. Cross-sectional data, flow data, and sediment data were used in conjunction with HEC-RAS. The simulation results reveal that sediment transport below the E.B. Campbell Dam is limited, leading to notable sediment erosion. The selected study area has witnessed significant erosion during high-flow periods, particularly in the event of floods. Between 2012 and 2019, the riverbed elevation at the selected survey site decreased by approximately 0.45 m. The study findings corroborate that the Saskatchewan River and its delta have been impacted by human activities. Potential erosion and deposition below the E.B. Campbell Dam have been simulated for the selected site. The aim is to provide decision-makers or related stakeholders with insight into how dam operations can be adjusted to decrease erosion while sustaining hydrological, ecological, and environmental outcomes from human activities.

Hydrogeomorphology of the origin of the Amazon River, the confluence between the Marañón and Ucayali rivers

AbstractThe origin of the Amazon River is formed at the confluence of the Marañón and Ucayali rivers. Remote sensing and detailed hydrodynamics, sediment transport and bed morphology analysis under different hydrological conditions have been applied to understand the control mechanisms of the modern confluence, thus informing about ancient confluences. Results showed that: 1) meandering‐meandering confluences existed when bifurcated meandering channels from the Marañón River joined the meandering Ucayali River, 2) far‐field scale provided the boundary conditions for the near‐field scale processes. In the case of the Marañón River, the spatial frequency and displacement of incoming anabranching structures to the confluence location set the boundary conditions for the near‐field scale. In the case of the Ucayali River, the incoming hydrodynamics and bed morphology are governed by far‐field processes such as the occurrence of cutoffs, 3) high intensity secondary flows at large rivers were observed at far‐ and near‐field scales, where previous studies have reported that secondary flows are weak or nonexistence or mainly found downstream of confluences. Finally, 4) even though the Marañón River is larger compared with the Ucayali River, the confluence hydrogeomorphology is governed by the Ucayali River because of more developed and stronger secondary flows.

ANALISIS ENDAPAN SEDIMEN DASAR BENDUNG KAMUN TERHADAP TINGGI MERCU DAN KEHILANGAN DEBIT AIR SALURAN INDUK CILUTUNG BARAT KABUPATEN MAJALENGKA

Kamun Dam is a permanent weir with its water intake in the Cilutung River Basin (DAS). One major factor affecting water reduction at the weir is sediment settling at the upstream base. Effective and efficient management is crucial for irrigation water and networks to maximize benefits. Water loss from primary to secondary and tertiary channels negatively impacts irrigation system performance. The water flow through weirs and structures with varying discharges influences the water surface profile and its characteristics.This research aimed to determine the water level, total sediment transport capacity, water discharge loss in the West Cilutung main channel, and the water surface profile shape. The data comprised primary data from field investigations and secondary data, including average discharge data from 2008-2017.Water level analysis was performed using hydraulic formulas and the Trial and Error method. The highest water level recorded was 0.74 m in April, and the lowest was 0.22 m in August. Sediment transport analysis, using the Meyer-Peter Muller method, estimated that it would take approximately 13 years to fill the upstream of Kamun Dam with 1,436,470.04 m³ of sediment, without dredging, given a river width of 74.15 m and height of 3 m. Water discharge loss analysis, using the inflow and outflow method, showed Qrenc results from BLK.1-BLB.1 at 0.06 m³/sec and Qactual at 0.27 m³/sec. The water surface profile analysis, using the graphical integration method, yielded Qrenc results for profile I f(y) = 4786 and Qactual results for profile I f(y) = 789

Climate change as main driver of centennial decline in river sediment transport across the Mediterranean region

The analysis of suspended sediment transport and of its variations over time is crucial for understanding environmental evolution and it is the key to future challenges caused by current global warming. The Mediterranean area is a hot spot for global changes, and the variation of precipitation amount and intensity will modify the environment of this region.In this work, we analyse the time series of suspended sediment transport of two rivers located in central Italy by using statistical and artificial intelligence techniques. Our study aims to re-analyze time series of suspended sediment transport, in order to demonstrate that climate change is responsible for the substantial decrease in the amount of sediment over the past century, in relation to the atmospheric teleconnections of the North Atlantic. Anthropic pressures like reforestation, land use change, and dam building have influenced the sediment transport capacity of rivers, causing a reduction of sediment concentration in water.These results are key factors to determine the future management of the Mediterranean areas, where the future scenarios predict a greater drop in yearly precipitation, and therefore a possible further decrease in the sediment transport capacity of the rivers, with major consequences for coastal and fluvial environments.

Sediment transport analysis under combined action of waves and current using a novel semi-coupled computational fluid dynamics solver

Sediment transport analysis under combined action of waves and current using a novel semi-coupled computational fluid dynamics solver

Inter‐ and intra‐annual fluctuations and attribution analysis of runoff and sediment transport in the middle and lower Yangtze River

AbstractAssessing the changing regimes of runoff and sediment load in rivers, as well as analysing their underlying causes, is essential for maintaining the ecological integrity of rivers and promoting the sustainable development of water resources. Current methods of attribution analysis focus on accounting for the effects of climate change and human activities on inter‐annual variability in streamflow and sediment. However, the contribution of individual drivers to intra‐annual hydrologic variability is often overlooked. The study analysed the inter‐ and intra‐annual fluctuations in runoff and sediment load in the middle and lower Yangtze River using a water‐sediment variation attribution model, the Extreme Gradient Boosting algorithm, and the Multiple‐Factor Attribution method. The results showed that human activities were responsible for over 70% of the inter‐ and intra‐annual fluctuation in runoff and sediment load in the Yichang, Hankou, and Datong sections. Additionally, it was found that human activities were the main contributor to the reduction in both runoff and sediment load in all sections. Closer to the Yangtze estuary, human influence on intra‐annual fluctuation of runoff decreases while climate change influence increases, and human influence on both inter‐ and intra‐annual fluctuation of sediment load becomes less significant. The sensitivity of annual runoff to precipitation is greater than that of air temperature and evaporation in the Yichang, Hankou, and Datong sections. An increase of 10% in precipitation from baseline values leads to a corresponding increase of 3.13%, 2.24%, and 3.91% in runoff for the Yichang, Hankou, and Datong sections. The annual sediment load is more sensitive to changes in runoff than to precipitation, air temperature, and evaporation in each section. A 10% increase in runoff from the baseline value leads to an annual sediment load increase of 20.36%, 10.11%, and 8.78% at Yichang, Hankou, and Datong, respectively. This study provides a theoretical basis and guidance for decision‐making to protect and sustainably develop the water and sediment resources in the Yangtze River Basin.

Modified stochastic diffusion particle tracking model driven by skew Brownian motion: Analysis of sediment particle motion in turbulent flow under the effects of ejection and sweep.

Turbulent bursting events have been classified into outward interactions (Q1), ejections (Q2), inward interactions (Q3), and sweeps (Q4) in various studies. Ejections (Q2) and sweeps (Q4) have been identified as significant contributors to time consumption, momentum flux, and sediment flux. Additionally, research has shown that the distribution of these events varies nonuniformly at different bed elevations. Despite extensive investigations into the nonuniform distribution of turbulent bursting events, their impact on sediment transport has been rarely explored. In this work, we developed a modified stochastic diffusion particle tracking model (SD-PTM) driven by skew Brownian motion (SBM) using the stochastic Lagrangian approach to scrutinize sediment particle movement in turbulent flows. The model incorporates turbulent characteristics derived from a direct numerical simulation dataset, allowing for a comprehensive analysis of sediment particle dynamics. Moreover, the proposed model accounts for the nonuniform spatial distribution of ejection and sweep events, as well as the particle movement direction during these events. Numerical simulations of the model were conducted to trace sediment particle trajectories in the streamwise and vertical directions. The analysis of sediment transport involved calculating the variance of particle trajectories to examine anomalous diffusion. The model's performance was evaluated by comparing it with flow velocity and sediment concentration profiles obtained from measurements in previous studies. In conclusion, our study suggests that the motion of sediment particles in turbulent flow can be thoroughly investigated under extreme flow conditions using the modified SD-PTM driven by SBM.

ANALISIS ANGKUTAN SEDIMEN PADA SUNGAI CISEEL DENGAN METODE SHEN AND HUNG

The Ciseel watershed is a river that has flood problems which had submerged an area in Ciamis Regency and Banjar City, the purpose of this study was to analyze sediment transport in the Ciseel watershed using the shen and hung method in reducing the impact of flooding which was carried out from June to August in year 2023. The method used in this study is a survey method, namely by making direct observations to the location of the Ciseel river to obtain data as material for conducting sediment research analysis using the shen and hungs method.The results of the analysis of sediment transport in the Ciseel River using the Shen and Hungs method in the upstream section show that the load sediment transport is 55.58 tons/year, in the middle section it is 46.62 tons/year, then in the downstream section it is 5.84 tons/year.

River capacity prediction based on flood discharge probability scenario and sediment transport consideration: Study Case in Sayung River

Pantura road at estuary of Sayung River is often flooded because it has a lower elevation than the river embankment. To avoid this, we must know the flood capacity of the river so that we can plan flood control and maintenance of river channels. Usually in flood prevention planning, it only design structure with unsteady flow model without sediment transport analysis. It is contrary with river nature because bed and river bank will easily erode, then transported as sediment and deposited in the lower reaches of the river. It makes river geometry will vary along with increasing of sedimentation. Therefore, capacity of the river will be analyzed with sediment transport using HEC-RAS 6.2 quasi unsteady flow model. Based on transport sediment simulation, sediment material deposition at Sayung River is 45,000 m3 every year. It makes river capacity decreased. Sayung River capacity is currently 242.15 m3/s, in 2023 is 200 m3/s, in 2024 is 185m3/s, in 2025 is 170 m3/s, year 2026 is 155 m3/s, in 2027 is 140m3/s, in 2028 is 120m3/s, in 2029 is 100m3/s, in 2030 is 77.5m3/s.

Long-term spatial and temporal trend analysis of stream flow and suspended sediment transport of Godavari River Basin, India

Long-term spatial and temporal trend analysis of stream flow and suspended sediment transport of Godavari River Basin, India

An experimental study on monitoring of marine sediment transport by using a 3D sediment trap

The observation and analysis of sediment transport in oceans is an important means for the protection of the marine environment, resource development, construction engineering, and element cycling. However, traditional methods of observing sediment transport are either limited by the range of the instruments used or their own observational attributes, such that they cannot be used to accurately detect and analyze the process of transport of marine sediment. A 3D sediment trap has been proposed to compensate for the shortcomings of the various monitoring tools in our team, but no mature method for the analytical inversion of the data obtained from this device has been developed to date. In this paper, we developed analytical methods to invert sediment transport processes using corrected capture efficiency, sample inversion, and transport flux analysis. Through an annular flume test, we measured the turbidity, pressure, and particle size of the water stream and substituted them into the proposed analytical equations, thus verifying the applicability of the analytical methods. We used the slice experiment of the time series of the sediment samples, to determine the validity of the sample inversion, and establish the relationship between the particle size and concentration of the captured samples. We performed restoration tests on the process of sediment transport to establish a set of methods of flux analysis based on the velocity and turbidity of flow. And finally corrected for capture efficiency by particle size. The combination of analytical methods and 3D sediment trap could provide technological support for investigating the evolution of the sea, ecological cycle, and marine engineering.

Airflow Dynamics and Aeolian Sand Transport Across a Beach‐Climbing Dune‐Clifftop Dune System

AbstractThis study presents an analysis of wind flow and sediment transport from the beach up a 50 m high, long (130 m), steep (mean slope 26°) climbing dune and across a 1.5 m high max, 85 m long and 17.5 m wide clifftop dune 30 km south of Dakhla in Morocco, NW Africa, during highly oblique incident wind conditions. Multiple 2D sonic and cup/vane anemometers and sand traps were utilized for measurements. Flow steering was significant on the upper climbing dune. Flow deceleration occurred near the dune toe, and topographic forcing of flow was considerable on the upper slopes of the climbing dune. Near‐surface flow steadiness (CVU1, CVU0.25) on the climbing dune straight slope segment was low and constant. The distance upslope over which the airflow reached a speed comparable to that on the beach increases as the incident wind speed increases. The greatest flow acceleration and speed‐up was observed at the cliff edge reaching 250% at 1 m height and 220% at 0.25 m height for the lowest incident wind speed class (4–5 m/s). The sand transport rate declined from the beach to the climbing dune toe and lower slope, but at the uppermost section of the climbing dune was 4 times higher than in the beach for the 7–8 m/s incident wind speed. Sand in aeolian transport was generally finer than surface sand, with the mean grain size increasing up the slope. A comparison of the sand transport data collected with sand transport models, and the effects of slope on Aeolian transport are also examined.

PRELIMINARY INVESTIGATION OF SHORELINE RESPONSE IN SAN JUAN, LA UNION, PHILIPPINES

Coastal erosion has been affected by environmental factors and human development. The investigation of the coastal erosion in San Juan, La Union covers the analysis and quantitative data that can be applied to protect the coastal community, to minimize economic losses, and to plan for the improvement of coastal process response. The main objective of this study was to investigate the shoreline response based on the extent of the coastal erosion problem of the 5.36 km - coastline of San Juan La Union and predict the long-term erosion pattern and shoreline change. The characteristics of the triggering factors of coastal erosion were evaluated during normal and extreme weather conditions. The areas along the coastline were characterized whether it experienced dominant deposition or erosion. Changes in shoreline position were assessed to predict future shoreline change scenarios. Sediment transport analysis was conducted by using the Kamphuis Formula and the CERC Formula.

Sediment Transport and Suspension Analysis to Support Development Planning for Port Pota, East Nusa Tenggara, Indonesia

Sediment Transport and Suspension Analysis to Support Development Planning for Port Pota, East Nusa Tenggara, Indonesia

ITERATIVE REFRACTION-CORRECTION METHOD ON MVS-SFM FOR SHALLOW STREAM BATHYMETRY

Abstract. Extracting accurate bathymetric information from clear, shallow waters in complex riverine environments can be challenging, but it is crucial for many applications, such as hydraulic modeling, ecological monitoring, and sediment transport analysis. Multi-view stereo photogrammetry (MVS-SfM) has emerged as a promising technique for acquiring high-resolution bathymetric data from aerial imagery. However, the accuracy of MVS-SfM can be affected by various factors, including water refraction, which can distort the depth measurements. In this study, iterative Dietrich’s refraction-correction method is tested for extracting bathymetry from MVS-SfM in a complex riverine environment. Moreover, we proposed a workflow for applying the method using raster data files, which can be more readily available than point clouds. It also compared the obtained results with previous applications and evaluated them using statistical indices and ratios. For this case study, the multicamera refraction method produces bathymetric datasets with accuracies of ~0.019% of the flying height and precisions of ~0.07% of the flying height. This study contributes to increased confidence in exploiting aerial imagery for bathymetric mapping in photogrammetric procedures under field conditions and can facilitate the management and conservation of clear water systems.

Comparative Study of Sediment Transport using the Caldwell and Cerc Methods at the Donggala Fish Landing Base

Donggala Fish Landing Port (PPI) is a fish port located in Central Sulawesi, precisely in Labuan Bajo Village, Banawa District, Donggala Regency, which is located along the high seas coast. The change in shoreline at the Donggala Fish Landing Base is caused by sediment transport that occurs due to wind and incoming waves. This study aims to determine the sediment characteristics, the amount of longshore sediment transport that occurs per year, and the ratio of the amount of sediment transport for 10 years using the Caldwell method and the CERC method. Analysis of sediment characteristics was carried out by testing carried out in the laboratory with the analyzed parameters, namely: sediment density, sediment grain size distribution and sedimentation velocity. There are many methods that can be used to calculate sediment transport, including the Caldwell method and the CERC method. The results of the sedimentation analysis, it is found that the sediment fraction is sand with various diameters, namely ϕmin = 0.075 mm and ϕmax = 25 mm, sediment density γmin = 2,604 g/cm3 and γmax = 2,678 g/cm3 and sedimentation velocity Wmin = 0.251 m/s and Wmax = 9,946 m/s. From the calculation of sediment transport analysis using the Caldwell method, the maximum amount of sediment transport that occurred in 2009 was 0,956 m3/year and for the CERC method, the maximum amount of sediment transport occurred in 2009 was 0,210 m3/year. The calculation of sediment transport analysis that was reviewed for 10 years, the value obtained by the Caldwell method Qs = 3,353 m3/year, while the CERC method Qs = 0,705 m3/year so that the amount of sediment transport using the Caldwell method is greater than using the CERC method.

Numerical analysis of sediment transport and depth averaged flow velocity in non-prismatic compound channels

The flow velocity in compound open channels is greatly affected by the geometry of both the main channel (MC) and floodplain (FP). In this study, a numerical investigation of the joint effect between the FP divergence angle and the size of suspended sediment particles on sediment transport and flow depth-averaged velocity (DAV) in non-prismatic diverging compound channels was conducted. In addition, the influence of relative flow depth on the DAV in different flow directions (i.e., stream-wise and span-wise) was examined. Three divergence angles of 4.0, 6.3 and 11.3°, four sediment particle sizes of 1, 5, 50 and 500 µm and two relative depths of the FP with respect to the MC of 0.20 and 0.40 were considered during simulations. A Computational Fluid Dynamics (CFD) software ANSYS-Fluent was used to perform the required simulation scenarios and the DAV was expressed in terms of a dimensionless velocity (i.e., relative depth-averaged velocity; RDAV) to generalize the use of the obtained results. Results revealed that the span-wise RDAV gradient between the MC and FP at the middle and the end sections of the divergence reach is much larger in the case of higher divergence angle. Moreover, the presence of coarse sediment particles in the sediment-laden flow resulted in an augmentation in the fluctuations of span-wise and stream-wise RDAVs as compared to those obtained in the case of fine sediment particles. Results also showed that the span-wise RDAV gradient between the two subsections (MC and FP) increases with decreasing the relative flow depth. Sediment particle size had a considerable impact on the span-wise RDAV values, especially in the case of lower relative depth. As the sediment particle size increases, the distortion in the span-wise RDAV distribution curves increases. However, the stream-wise RDAV along the MC and FP decreases, as the sediment particle size decreases, especially in the case of higher relative depth. Based on the results, it can be concluded that the span-wise DAV gradient was greatly affected by the FP divergence angle and sediment particle size. The fluctuations in the span-wise DAV gradient were more pronounced in the case of higher divergence angles and coarser sediment particles. The stream-wise DAV distribution along the MC and FP was mainly influenced by the relative depth and sediment particle size. The stream-wise DAV dip along the MC and FP was more explicit in the case of higher relative depths and finer sediment particles.