International Journal of Sediment Research最新文献

{"title":"Suspended sediment concentration within submerged vegetation canopies: An improved method","authors":"Shanghong Zhang ,&nbsp;Hao Jia ,&nbsp;Caihong Tang ,&nbsp;Yujun Yi ,&nbsp;Yinghao Zhang ,&nbsp;Qipeng Mou","doi":"10.1016/j.ijsrc.2025.09.004","DOIUrl":"10.1016/j.ijsrc.2025.09.004","url":null,"abstract":"<div><div>Aquatic vegetation plays a crucial role in regulating sediment transport and maintaining the stability of aquatic ecosystems. To investigate the turbulence structure and suspended sediment distribution under the influence of natural flexible submerged vegetation, this study selected <em>Vallisneria natans</em> (eelgrass), a representative flexible submerged plant, as the experimental material. Systematic measurements of flow structure and suspended sediment concentration (SSC) were conducted under submerged vegetation conditions. The experimental results demonstrated that the presence of flexible vegetation significantly altered the vertical distribution of flow velocity and turbulence characteristics. Under different vegetation densities, noticeable variations were observed in time-averaged velocity, lateral and vertical Reynolds stresses, and turbulent kinetic energy (TKE), with particularly pronounced changes in the near-bed and canopy regions. Compared to the bare bed condition, SSC in vegetated flows was significantly reduced, and the reduction became more evident with increasing vegetation density. To predict the SSC profiles under flexible vegetation conditions, the vertical distribution of the turbulent diffusion coefficient was calculated. Results showed that the coefficient exhibited a linear distribution within the canopy, reaching a maximum near the canopy top. Based on this distribution pattern, an improved Rouse equation applicable to submerged flexible vegetation conditions was proposed. The modified Rouse model was validated against measured SSC profiles under various vegetation densities and hydraulic conditions, demonstrating its ability to accurately predict the vertical distribution of suspended sediment. This study provides theoretical support for sediment transport modeling, hydrodynamic regulation, and ecological restoration in vegetated riverine and lacustrine environments. It also lays a foundation for advancing the understanding of the coupled interactions among flow, sediment, and vegetation.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"41 1","pages":"Pages 135-144"},"PeriodicalIF":3.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term succession of fish biodiversity in the Yellow River Estuary under the influence of water–sediment regime changes","authors":"Yiping Wang ,&nbsp;Yongjun Lu ,&nbsp;Huaixiang Liu ,&nbsp;Yaohui Hu ,&nbsp;Xinhou Zhang ,&nbsp;Mingcheng Zhu ,&nbsp;Yuhong Zeng","doi":"10.1016/j.ijsrc.2025.10.001","DOIUrl":"10.1016/j.ijsrc.2025.10.001","url":null,"abstract":"<div><div>The estuarine reach of the Yellow River (YRE), located within the core zone of the Yellow River Delta Reserve, serves as a critical zone where the conservation and restoration of fish biodiversity constitute essential elements for achieving high-quality development in the Yellow River Basin. However, the fish population in this area is subject to multiple disturbances (especially water‒sediment regime changes), and because of the year-round fishing ban, relevant data are lacking. By integrating historical fish species records with water‒sediment phases classified via Bayesian mutation analysis and key drivers identified via principal component analysis, this study elucidates the reasons for the evolution of fish biodiversity. The results revealed mutation points of the annual runoff (2001) and sediment load (2004) in the YRE during 1950–2023, with a marked declining trend preceding these shifts (<em>P</em> &lt; 0.05), accompanied by fluctuations in fish taxonomic diversity and obvious changes in the dominant fish ecological types. Moreover, the key water–sediment factors influencing fish biodiversity were associated primarily with fish reproduction and migration during the investigation periods, including the proportion of monthly mean discharge relative to the natural baseline phase, minimum daily ecological flow guarantee rate, and annual flow cessation days in zero-flow years. We emphasize that these findings are based on empirical observations from implemented water regulations, but the causal relationship requires rigorous testing via process-based models or controlled experimental studies. Nevertheless, this study still provides the necessary empirical data and initial hypotheses for subsequent research, which can serve as a reference for optimizing protection measures for the YRE.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"41 1","pages":"Pages 170-181"},"PeriodicalIF":3.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Short-term effects of polyacrylamide application on soil detachment capacity in rills of deforested hillslopes: A flume experiment","authors":"Misagh Parhizkar ,&nbsp;Manuel Esteban Lucas-Borja ,&nbsp;Nikolaos Tziolas ,&nbsp;Pietro Denisi ,&nbsp;Demetrio Antonio Zema","doi":"10.1016/j.ijsrc.2025.07.013","DOIUrl":"10.1016/j.ijsrc.2025.07.013","url":null,"abstract":"<div><div>Very few studies have explored the effectiveness of polyacrylamide (PAM) application on soil in mitigating rill erosion, especially in deforested environments. This study has measured the soil detachment capacity (<em>D</em>_c) on samples of deforested soil (untreated or treated with PAM). <em>D</em>_c has been estimated by flume experiments under three bed slopes (6.9 %, 17.2 %, and 18.2 %) and five flow discharges (0.078, 0.096, 0.116, 0.138, and 0.154 L·s⁻¹) together with three key soil properties (cation exchange capacity, mean weight diameter of soil aggregates, and organic matter content). Compared to the untreated soil, <em>D</em>_c has significantly (<em>p</em> &lt; 0.05) decreased on average by 38 % after the PAM application, while the cation exchange capacity, stability of soil aggregates, and organic matter content have increased (<em>p</em> &lt; 0.001) by 50 % to over 100 %. However, <em>D</em>_c is weakly correlated to the latter soil properties (<em>r</em> &lt; 0.33, <em>p</em> &lt; 0.05). A clear discrimination between treated and untreated sites has been revealed by a multivariate statistical analysis. The soil erodibility parameter (<em>K</em>_r) and critical shear stress (<em>τ</em>_c) in rills have also been estimated through linear regressions on <em>D</em>_c for use in erosion models. <em>D</em>_c can be accurately estimated by linear equations using the stream power as a predictor (<em>R</em>² &gt; 0.77). Overall, the study has demonstrated that PAM is an effective soil amendment that reduces soil detachment in rills of deforested hillslopes by about 40 %.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"41 1","pages":"Pages 145-154"},"PeriodicalIF":3.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of sediment resuspension in shallow lake under variable wind speed and water depth","authors":"Wenguang Luo ,&nbsp;Yan Pan ,&nbsp;Jing Lu ,&nbsp;Jinxiao Zhao","doi":"10.1016/j.ijsrc.2025.06.011","DOIUrl":"10.1016/j.ijsrc.2025.06.011","url":null,"abstract":"<div><div>Understanding wind-induced sediment resuspension is essential for predicting turbidity dynamics and nutrient cycling in shallow lakes. This study investigates the spatial variability of sediment resuspension under different hydrodynamic conditions and quantifies the influence of wind-driven forces on sediment stability. A controlled laboratory experiment was conducted using a wind-generation system comprising 13 rows of fans positioned at varying distances and angles with respect to three distinct regions (A, B, and C). Turbidity variations exhibited a strong linear correlation with the dimensionless parameter (<em>W</em>²/<em>H</em>) (<em>R</em>² = 0.85–0.92), where <em>W</em> represents wind frequency (Hz) and <em>H</em> denotes water depth (m). This parameter effectively captures resuspension sensitivity. Further analysis showed that W, which reflects the proximity to the wind source, integrates the effects of both wind angle and position. Using the 50 NTU water quality threshold, critical (<em>W</em>²/<em>H</em>) values were determined as 2787, 7176, and 16,771 for regions A, B, and C, respectively—corresponding to wind frequencies of 17 Hz, 27 Hz, and 41 Hz at a depth of 0.1 m. Accordingly, regions B and C require approximately 1.6 and 2.5 times more wind energy than region A to reach the same turbidity level. These findings establish a quantitative relationship between wind-driven turbulence and sediment transport, providing insight into the spatial heterogeneity of sediment stability. This research offers both theoretical and practical implications for water quality management, including optimizing artificial aeration, mitigating eutrophication, and improving sediment regulation strategies in shallow lake ecosystems.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"41 1","pages":"Pages 36-44"},"PeriodicalIF":3.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bed roughness effects on horseshoe vortex dynamics and soil erosion mechanisms in vegetated overland flows","authors":"Huilan Zhang ,&nbsp;Fangzheng Gu ,&nbsp;Shaoqin Xia ,&nbsp;Feng Li ,&nbsp;Ping Wang ,&nbsp;Linghan Wang ,&nbsp;Di Zhang ,&nbsp;Yanchong Duan ,&nbsp;Qigang Chen","doi":"10.1016/j.ijsrc.2025.07.004","DOIUrl":"10.1016/j.ijsrc.2025.07.004","url":null,"abstract":"<div><div>Understanding how bed roughness modulates hydrodynamic processes around vegetation is critical for predicting soil erosion patterns in sloped landscapes. Through flume experiments with high-frequency particle image velocimetry (PIV), this study quantifies the interactions between bed roughness (<em>k</em>_<em>s</em> = 0.009, 0.25, 0.75, 1.55) and horseshoe vortex (HV) dynamics under overland flow conditions (<em>Re</em>_<em>D</em> = 2627–3815). Time-averaged flow field analysis, based on vorticity and swirl strength methods, revealed that increasing surface roughness disrupted the HV system by reducing the number of vortices, decreasing the vorticity and swirl strength of the primary HV, and shifting its position closer to the bed. Statistical analysis of the instantaneous velocity components showed the emergence of bimodal probability density functions (PDFs) and joint probability density functions (JPDFs) in the near-wall region upstream of the cylinder, representing the backflow and downflow events. As roughness increased, the bimodal region decreased in size and shifted further from the cylinder. Linear stochastic estimation (LSE) was used to characterize the underlying flow modes, indicating that the backflow event was associated with the backflow mode, while the downflow event was linked to the zero-flow mode. Notably, roughness elements enhanced flow stagnation (zero-flow mode dominance &gt; 60 %), suggesting a potential mechanism for erosion mitigation. These findings provide quantitative linkages between micro-scale hydrodynamics and landscape-scale erosion processes, informing the design of vegetation-based erosion control strategies through targeted roughness manipulation.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"41 1","pages":"Pages 110-124"},"PeriodicalIF":3.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sedimentary organic matters within the subtropical mountainous river-estuary-bay continuum: Provenances, fates and implications","authors":"Fengling Yu ,&nbsp;Junyang Ma ,&nbsp;Zhaoquan Huang ,&nbsp;Chengcheng Gao ,&nbsp;Yishu Hou ,&nbsp;Liangrong Zou ,&nbsp;Dan Yu ,&nbsp;Nengwang Chen ,&nbsp;Siguang Liu ,&nbsp;Tian Xia","doi":"10.1016/j.ijsrc.2025.07.005","DOIUrl":"10.1016/j.ijsrc.2025.07.005","url":null,"abstract":"<div><div>Deep insight into the spatialtemporal composition and distribution dynamics of suspended particulate organic carbon (POC) and sedimentary total organic carbon (TOC) within the mountainous river-estuary-bay continuum provides us with a unique perspective for examining the impact of estuarine flow on the material cycle within the river-estuary-bay systems. In this study, we conducted a comparative analysis of the river-estuary-bay continuum of two subtropical mountainous rivers, the Jiulong River (JLR) and the Zhangjiang River (ZJR), southern China. Seasonal samples of suspended particles and surface sediments were collected from the lower river reaches, estuaries, and bay areas. Both suspended and sedimentary samples were analyzed for organic content and their isotopic signatures (δ¹³C), and C/N ratios. The results reveal notable differences between the two systems. The JLR system exhibits stronger seasonal and spatial variations in POC sources compared to the ZJR system. In contrast, the estuary and bay of the ZJR system show more pronounced marine POC signals than those of the JLR system. In the sediments of the estuary and bay, soil organic matter and C₃ plants contribute to over 60 % of the total organic matter in the JLR system, whereas in the ZJR system, marine organic matter and soil are the two most significant contributors. This study identifies that estuarine hydraulic conditions control the provenance, dynamics, and fate of particulate organic matter (POM). River discharge plays a pivotal role in regulating the dispersion of terrestrial organic matter in the estuary; Estuarine circulation and the position of the turbidity maximum zone govern the temporal and spatial distribution of sedimentary organic matter. Moreover, high soil contribution to the estuarine and bay sediment organic matter suggests strong soil erosion of adjacent land, likely attributed to human activities. Our findings highlight the high sensitivity of POC composition and dynamics in these mountainous river-estuary-bay systems to changes in river discharge, tidal current, and maybe wave conditions. The results of this study will deepen our understanding of the dynamics and fate of POM from different sources within the mountainous river-estuary-bay continuum and provide vital information for the effective management of these highly dynamic and sensitive ecosystems.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"41 1","pages":"Pages 72-82"},"PeriodicalIF":3.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"River system sediment rating curve parameter estimation via integrated models","authors":"Tushar Khankhoje,&nbsp;Samrat Boro,&nbsp;Parthasarathi Choudhury","doi":"10.1016/j.ijsrc.2025.06.010","DOIUrl":"10.1016/j.ijsrc.2025.06.010","url":null,"abstract":"<div><div>Continuous water and sediment flow monitoring across river cross sections is essential for the management of flood- and sediment-related problems in watersheds. The sediment rating curve (SRC) estimates missing or uncertain sediment flow via its corresponding water discharge. Generally, a power form of relationship correlates the two quantities. The log-transformed water discharge and sediment discharge data were used to depict the SRCs developed in the present study. SRC parameter estimation via least squares regression using at-site dataset pairs can be found in the literature. However, the availability of reliable datasets at the site limits model applicability. This method does not describe the SRC on the basis of the continuity aspects of river system flow characteristics. Therefore, the current study proposes integrated SRC estimation models (Model 2 and Model 3) using modified Muskingum equations abiding by the spatial and temporal continuity of the entire river system state. These models are derived from streamflow storage balance criteria and ensure flow continuity norms. Moreover, Model 3 considers an inverse power form of the relationship depicting the water flow characteristics that govern the sediment transport phenomena through the river system. Standalone models for SRC parameter estimation (Model 1) were also developed for comparison among all three models via the root mean square error (RMSE), NRMSE (normalized root mean square error) and coefficient of determination (<em>R</em>²). The Mahanadi River system within Chhattisgarh state, India comprises five sections at tributaries, and the main channel was considered for the study. The improved NRMSE by Model 2 (7.53%) and Model 3 (7.14%) at Rajim and Model 3 (3.44%) at Bamnidhi in comparison to Model 1 at Rajim (9.19%) and Bamnidhi (4.80%) encouraged the application of integrated models for SRC estimation in river systems. Moreover, Model 3 outperformed Model 2 in some cases where the sediment transport process may be governed by water flow characteristics.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"41 1","pages":"Pages 45-59"},"PeriodicalIF":3.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sediment coarsening in the Yellow River subaqueous delta: Regional patterns, causes, and implications","authors":"Yaoshen Fan ,&nbsp;Guangzhou Wang ,&nbsp;Shentang Dou ,&nbsp;Hongyu Ji ,&nbsp;Weiming Xie ,&nbsp;Peng Li ,&nbsp;Xiaokang Du ,&nbsp;Shoubing Yu ,&nbsp;Shaohua Zhang ,&nbsp;Chao Zhu","doi":"10.1016/j.ijsrc.2025.10.005","DOIUrl":"10.1016/j.ijsrc.2025.10.005","url":null,"abstract":"<div><div>Sediment coarsening in submerged deltas is commonly attributed to seabed erosion because of insufficient sediment input. The Yellow River subaqueous delta (YRSD) has exhibited distinct coarsening patterns following both accretion and erosion events. To investigate these contrasting mechanisms, grain size distributions, elevation changes, and bottom shear stress patterns were analyzed across the delta from 1992 to 2022. The results revealed distinct sedimentary patterns among the abandoned YRSD, active YRSD, southern Laizhou Bay, and adjacent Bohai Sea, with average median grain size (<em>D</em>₅₀) increases of 17, 17, 6, and 0 μm, respectively. Sediment coarsening occurred primarily from 1992 to 2000, when the river mouth position was artificially altered and fluvial sediment grain size increased from 16 to 29 μm. From 1992 to 2015, the active YRSD experienced accretion at a rate of 7.8 mm/yr. Moreover, the abandoned YRSD and southern Laizhou Bay experienced significant erosion. The erosion rates were −5.1 and −1.0 mm/yr, respectively. This led to the identification of two mechanisms of sediment coarsening: erosion-driven coarsening in sediment-deficient areas and accretion-driven coarsening where the input sediment grain size increased. Although marine processes did not intensify during this period, the bottom shear stress distribution changed substantially due to morphological evolution, with correlation coefficients between grain size and shear stress showing increasing trends in littoral zones. This strengthening relationship, coupled with the declining fluvial sediment load, demonstrates the YRSD transition from river-dominated to wave-dominated processes, providing important insight into delta evolution under changing sediment regimes. The insights gained can guide Yellow River Delta management through targeted strategies and provide essential evidence for predicting delta evolution.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"41 1","pages":"Pages 155-169"},"PeriodicalIF":3.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of the most suitable artificial neural network method for sediment estimation in the Euphrates-Tigris Basin","authors":"Ömer Faruk Karaca ,&nbsp;Kadri Yürekli","doi":"10.1016/j.ijsrc.2025.07.011","DOIUrl":"10.1016/j.ijsrc.2025.07.011","url":null,"abstract":"<div><div>In studies on water resources planning and management, regular and complete hydrological data such as streamflow and sediment data are needed. Since the existing data generally do not fully reflect the entire process, the process needs to be modeled in order to make more reliable decisions. The aim of this study is to investigate the possibilities of estimating the sediment amount with the ANN technique, which can be used in many areas today, with the streamflow and sediment measured from 20 sediment gauging stations (SGS) established by State Hydraulic Works (SHW) in the Euphrates-Tigris Basin and to try to determine the most appropriate network structure. The ANN structures to be used were determined as the most commonly used Radial Basis Artificial Neural Network (RBANN), Feed Forward Back Propagation Artificial Neural Network (FFBP) and Multilayer Artificial Neural Network (MLP). The obtained results were compared with the Multiple Linear Regression (MLR) method. The highest <em>R</em>² values obtained were determined as 0.9683 and 0.9969 in the RBANN model, 0.9546 and 0.9820 in the MLP model, 0.9735 and 0.9732 in the FFBG model with the CG and LM algorithms, respectively. When only the mean values of the test values according to the ANN models were examined, the highest value was again obtained as 0.8507 in the RBANN and LM algorithms. In terms of sediment estimation, the highest <em>R</em>² value in the ANN analysis was found in the RBANN model LM algorithm as 0.9804 in the train phase, 0.9969 in the testing phase and 0.9970 in the cross-validation phase.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"41 1","pages":"Pages 98-109"},"PeriodicalIF":3.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Turbulence structure and near-wall suppression in equilibrium and nonequilibrium sediment transport: An experimental study","authors":"Bambang Agus Kironoto ,&nbsp;Miskar Maini ,&nbsp;Adam Pamudji Rahardjo ,&nbsp;Istiarto","doi":"10.1016/j.ijsrc.2025.08.001","DOIUrl":"10.1016/j.ijsrc.2025.08.001","url":null,"abstract":"<div><div>Sediment transport in open channels plays a significant role in shaping turbulent flow structures, influencing sediment dynamics and flow resistance. Transport regimes are classified into equilibrium, where sediment inflow and outflow are balanced, and nonequilibrium, characterized by bed degradation. This study experimentally investigated the turbulence characteristics of sediment-laden, low-velocity open-channel flows under two conditions: sediment-feeding (SF) flows representing equilibrium and nonsediment-feeding (NSF) flows representing degradation-type nonequilibrium conditions. Laboratory experiments were conducted in a 10-m recirculating flume using a 16-MHz acoustic Doppler velocimeter (ADV). Velocity and turbulence profiles were collected under fixed- and movable-bed configurations using two sediment types (<em>d</em>₅₀ = 1.55 and 1.85 mm) simulating tropical riverbeds. Analyses of velocity profiles, turbulence intensities, Reynolds shear stress, mixing length, eddy viscosity, energy spectra, velocity correlations, and turbulence scales were performed. The results reveal clear distinctions between the SF and NSF flows, particularly near the bed. Sediment feeding reduces the near-bed velocity gradient (d<em>u</em>/d<em>y</em>), suppresses near-wall turbulence, and shifts the turbulence intensity peak upward to <em>y</em>/<em>H</em> ≈ 0.15. It also significantly reduces the Reynolds shear stress, whereas changes in the eddy viscosity near the bed are less pronounced because of the dominant velocity gradients. A hybrid model combining exponential and power-law terms is proposed to better represent the turbulence intensity and shear stress profiles under sediment-feeding conditions. Spectral analysis confirmed that, despite the 50 Hz sampling limit of the ADV, the inertial subrange follows Kolmogorov's −5/3 law, although the dissipation range was not captured, and microscale estimations remain approximate. Compared with sediment feeding, increased bed roughness reduces turbulence scales, whereas bed mobility effects are secondary. Shear velocity estimates derived from the Clauser, energy gradient, and Reynolds shear stress methods indicate that turbulence-based methods yield more consistent results in sediment-laden flows. These findings advance the understanding of sediment–turbulence interactions and improve sediment transport modeling for low-velocity open channels. Furthermore, these insights can be applied to enhance predictive modeling, optimize sediment management strategies, and support the design of more resilient river engineering structures, particularly in tropical systems.</div></div>","PeriodicalId":50290,"journal":{"name":"International Journal of Sediment Research","volume":"41 1","pages":"Pages 1-22"},"PeriodicalIF":3.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145929122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}