Table of Contents
Overview
Definition and Importance
Sediment transport is defined as the mechanism through which hydrodynamic processes lead to morphological changes in various environments. It is a critical process that facilitates the movement of sediment, which is essential for the formation of features such as beaches. Without sediment transport, these coastal formations would not exist, highlighting its fundamental role in shaping landscapes.[1.1] The study of sediment transport encompasses both the movement and deposition of sediments, which are vital processes in sedimentology. Once sediment is transported, it can be deposited in diverse environments, including river channels, lakes, deltas, beaches, and deep marine basins. Understanding these processes is crucial for comprehending the formation of sedimentary rocks and the specific environments in which they are deposited.[2.1] Sediment transport has been a subject of research for centuries and continues to pose challenges for earth and marine scientists. Its importance is underscored by its implications for various natural and anthropogenic processes, including river dynamics, coastal erosion, and sedimentary rock formation. The ongoing study of sediment transport is essential for advancing knowledge in fields such as geology, hydrology, and environmental science.[3.1]Key Processes in Sediment Transport
Sediment transport is a complex process influenced by various hydrodynamic conditions and physical characteristics of sediments. Key concepts in sediment transport include viscosity, boundary layers, shear stress, and Shields stress, which are essential for understanding how sediment size is characterized and how it settles according to Stokes' law.[4.1] The dynamics of sediment transport are particularly pronounced during flood seasons, where heightened concentrations of sediment transport necessitate the integration of sediment dynamics into flood risk management strategies.[7.1] This is critical as sediment transport processes can significantly impact river engineering, particularly in addressing the discrepancies between sediment surplus in upstream areas and deficits downstream, which can lead to challenges in flood protection and riverbed degradation.[6.1] Effective sediment management strategies are vital for mitigating these challenges. One primary approach is to reduce sediment yield from upstream sources by implementing erosion control methods and trapping sediment before it reaches reservoirs.[8.1] Additionally, innovative flood modeling frameworks have been developed that incorporate both flood control and sediment transport considerations, enhancing the effectiveness of management strategies.[9.1] In coastal environments, sediment transport is predominantly influenced by the combined action of waves and currents. The suspended sediment concentration and transport in these regions are governed by hydrodynamic conditions, which control sediment resuspension, mixing, and transport processes.[16.1] The maximum sustained rate of gravity-induced sediment transport occurs under strong ambient currents when the supply of easily suspended sediment exceeds the resuspension capacity of these currents.[15.1] Understanding these interactions is crucial for predicting sediment behavior and managing sediment-related challenges in both riverine and coastal systems.In this section:
History
Evolution of Sediment Transport Research
The study of sediment transport has evolved significantly over the past century, beginning in the 1920s with foundational research that laid the groundwork for understanding the mechanics of sediment movement. This period marked the initiation of systematic investigations into how sediment particles are entrained and transported by fluid flows, a process that remains complex and not fully resolved today.[45.1] Over the decades, sediment transport research has expanded to encompass both fundamental and applied aspects, reflecting its importance in geological processes and human activities.[44.1] The mechanics of sediment transport have been a focal point of study for more than 70 years, with numerous advancements contributing to our understanding of sediment dynamics and morphodynamics.[46.1] A significant development in the field occurred in the 1930s when experimental work on sediment transport and bed forms, primarily conducted by engineers, was reintroduced to geologists. This cross-disciplinary collaboration was highlighted during an SEPM symposium on sedimentary structures, which helped bridge the gap between engineering and geological perspectives.[47.1] The importance of sediment transport extends beyond theoretical research; it plays a crucial role in the formation of sedimentary rocks and the evolution of various environments, including river channels, lakes, and coastal areas.[48.1] Recent advancements in technology and research methodologies have further enhanced our understanding of sediment transport processes. For instance, innovative modeling techniques have been developed to simulate sediment dynamics in reservoirs and shallow water bodies, addressing the complexities of sedimentation and deposition.[59.1] As the field continues to evolve, ongoing research aims to fill knowledge gaps in morphodynamic processes and improve management practices in response to rapidly changing environmental conditions.[57.1] The integration of hydraulic engineering with sediment transport research is crucial for effective governance of aquatic environments, highlighting the economic and environmental implications of sediment dynamics.[58.1]Recent Advancements
New Findings in Sediment Dynamics
Recent studies have significantly advanced the understanding of sediment transport dynamics, particularly in relation to various environmental factors and sediment characteristics. One notable area of research involves the interaction between flow velocity and sediment transport. It has been observed that as sediment mass discharge increases, flow velocity tends to decrease, which can influence the transport dynamics of sediment particles in aquatic systems.[91.1] Additionally, the presence of vegetation has been shown to generate turbulence that affects sediment resuspension; specifically, the critical turbulent kinetic energy required for resuspension remains consistent across different sediment sizes, although the critical velocity decreases with an increase in solid volume fraction.[93.1] Flume experiments have also provided valuable insights into sediment transport under controlled conditions. These experiments have modeled the adjustments of channel morphology and sediment supply, revealing that flow resistance due to macro-roughness elements, such as boulders and step-pool sequences, plays a crucial role in regulating bedload transport rates in steep mountain streams.[97.1] Furthermore, the influence of bed-load transport on flow resistance and bed stability has been investigated, highlighting the complex interactions that govern sediment dynamics in steep channels.[96.1] The application of plutonium isotopes as tracers has emerged as a powerful tool for studying sediment transport processes. These isotopes serve as fingerprints for sediments, allowing researchers to trace sediment sources and understand the dynamics of sediment transport in both marine and fluvial environments.[87.1] This method has been instrumental in assessing anthropogenic impacts on sediment transport and has broadened the scope of sediment dynamics research. Moreover, the effects of flow unsteadiness, particularly during flood events, have been recognized for their significant impact on sediment particle motion and pollutant dispersion, emphasizing the need for further exploration of flow characteristics in unsteady conditions.[92.1] Overall, these advancements underscore the intricate relationships between flow dynamics, sediment characteristics, and environmental factors, paving the way for improved management practices and ecological assessments in sediment transport studies.Environmental Impact
Effects on Aquatic Ecosystems
River ecosystems are significantly affected by sediment transport, which plays a crucial role in maintaining ecological balance. However, excessive sediment loads can lead to detrimental impacts on water quality, threatening both human and environmental health. These impacts arise from complex mechanisms that alter the physical, chemical, and biological characteristics of aquatic environments, ultimately affecting the energy sources vital for aquatic ecosystems.[130.1] The construction of dams is a major anthropogenic factor that disrupts sediment transport. Dams trap sediment, which deprives downstream ecosystems of essential minerals and nutrients necessary for supporting plant and animal life. This interruption can lead to the shrinking of wetlands and contribute to the eutrophication of lakes, characterized by excessive algal growth.[134.1] Furthermore, the alteration of sediment dynamics can result in significant ecological consequences, including reservoir capacity loss, river channel erosion, and delta land loss.[134.1] Sediment also serves as a habitat for various aquatic species, providing cover and spawning sites for fish and food organisms. Changes in sediment transport can lead to a decline in benthic species, as the grain size distribution of the bed load shifts away from that of the bed material.[132.1] This decline can disrupt the food web and overall health of aquatic communities. For instance, the Ghaghra River in Uttar Pradesh and the Brahmaputra River, known for its sediment-rich waters, illustrate how human activities, such as dam construction and sand mining, can adversely affect sediment flow and, consequently, river health.[131.1] Moreover, climate change exacerbates these issues by altering flow patterns and sediment transport dynamics, leading to further degradation of river morphology and ecological stability.[138.1] The cascading effects of these changes can trigger regime shifts within ecosystems, as seen in the Yellow River, which has experienced significant alterations due to sediment management practices.[55.1] To mitigate these negative effects, implementing best management practices across various sectors, including agriculture and urban development, is essential. Additionally, incorporating environmental flows (e-flows) into dam operations can help maintain minimum water and sediment discharge downstream, thereby supporting the ecological health of river systems.[136.1] By addressing the impacts of sediment alteration, we can work towards preserving the integrity of aquatic ecosystems for future generations.Role in Landform Development
Sediment transport plays a crucial role in landform development, particularly in the context of climate change and human activities. The degradation of the cryosphere has significantly influenced riverine water and sediment fluxes, leading to varying seasonal and geographical effects on sediment transport processes.[156.1] For instance, alterations in seasonal sediment dynamics have been observed in cryosphere-fed rivers, which are characterized by different hydrological regimes such as glacial, nival, pluvial, and mixed.[157.1] These changes not only affect the cyclical supply of fluvial materials but also have implications for the water-food-energy provisions to downstream communities. Research indicates that the impacts of climate change on precipitation patterns and sediment transport are well-documented, with the ecological consequences being cumulative over time.[158.1] This long-term perspective is essential for understanding how sediment transport influences river morphology and surrounding ecosystems. For example, a study analyzing suspended sediment transport in central Italy demonstrated that climate change has led to a substantial decrease in sediment transport, highlighting the need for further investigation into these dynamics.[159.1] Moreover, specific case studies, such as those conducted in the Lena River delta, reveal that climate change is altering sediment regimes and stream hydromorphology. The primary driver of these changes has been identified as bank degradation due to thermal erosional processes, which are linked to rising air and soil temperatures.[160.1] This underscores the importance of understanding sediment transport not only as a physical process but also as a critical factor in shaping landforms and influencing ecological health in riverine environments.In this section:
Human Influence
Sediment Load Alterations Due to Urbanization
Urbanization significantly alters sediment loads in river systems, primarily through increased runoff and changes in land use. As urban areas expand, the transformation of landscapes leads to heightened sediment transport, which is essential for understanding the implications for aquatic ecosystems and water quality. Specifically, urban development has resulted in increased runoff that carries sediments, nutrients, pollutants, pharmaceuticals, and toxins downstream, thereby affecting both the physical and biological characteristics of aquatic environments.[190.1] The construction of infrastructure and the conversion of land for urban use disrupt natural sediment transport processes, leading to a rise in sediment loads that can overwhelm river systems. This excessive sedimentation can trigger a cascade of negative impacts on water quality, threatening the health of aquatic ecosystems.[192.1] For instance, sediments from urban runoff can suffocate coral reefs and promote harmful algal blooms, which further degrade water quality and disrupt aquatic habitats.[186.1] Moreover, the impacts of urbanization on sediment transport are not limited to immediate water quality issues; they also extend to long-term ecological consequences. The alteration of sediment loads can lead to habitat degradation, affecting biodiversity within aquatic ecosystems. Species that rely on specific sediment conditions for spawning or feeding may experience declines due to altered sediment dynamics.[191.1] To mitigate these impacts, it is crucial to adopt sustainable land management practices that integrate sediment control measures into urban planning. Implementing best management practices across agriculture, construction, and urban development can help minimize the negative effects of excessive sediment on vital water resources, ensuring the health of aquatic ecosystems for future generations.[192.1]Impacts of Dams and River Modifications
Dams and dikes significantly alter sediment transport dynamics in river systems, leading to various ecological consequences. The construction of dikes disrupts natural river flows and sediment transport processes, which can result in habitat fragmentation and changes in sedimentation patterns. Specifically, dikes can create barriers that hinder wildlife movement and alter sediment transport, potentially leading to erosion downstream or sediment accumulation upstream, which raises water quality concerns.[178.1] Dams, in particular, interrupt the continuity of sediment transport, causing sediment to accumulate within reservoirs. This accumulation not only impairs reservoir operation but also deprives downstream reaches of sediments that are essential for maintaining channel form and supporting riparian ecosystems.[180.1] The reduction of suspended sediment load and organic carbon downstream of dams affects benthic ecosystems by diminishing habitat quality, decreasing favorable conditions for native species, and disrupting nutrient flow.[179.1] Moreover, the trapping of sediment and nutrients by dams has led to significant ecological impacts, including loss of reservoir capacity, river channel erosion, delta land loss, and increased eutrophication in reservoirs. These changes contribute to massive greenhouse gas emissions, further complicating the ecological balance in affected areas.[181.1] Overall, the implementation of dams and dikes has profound implications for sediment transport and the health of riverine and coastal ecosystems.[177.1]Modes Of Sediment Transport
Bedload Transport
Bedload transport refers to the movement of sediment particles that are in continuous contact with the riverbed. This mode of transport is primarily associated with larger sediment grains, such as gravel and sand, which move along the bottom of a river or stream. The process of bedload transport can be characterized by two main types: traction and saltation. In traction, larger particles roll or slide along the riverbed, while in saltation, smaller particles are lifted off the bed and then fall back, creating a bouncing motion.[211.1] The dynamics of bedload transport are influenced by various factors, including flow velocity and sediment grain size. As the flow velocity increases, the ability of the water to lift and transport sediment also increases, leading to a greater rate of bedload movement. This interaction between flow and sediment can result in significant changes to river morphology, including bed aggradation and degradation.[219.1] Additionally, the presence of vegetation can affect bedload transport by stabilizing the sediment and reducing the flow velocity, which in turn decreases the amount of sediment that can be transported.[213.1] Understanding bedload transport is crucial for sedimentology, as it plays a significant role in the formation of sedimentary rocks and the overall health of aquatic ecosystems. The study of bedload transport also has practical implications for river management and engineering, as it helps predict sediment movement and its impact on river channels.[213.1]In this section:
Applications
Coastal Engineering
Coastal engineering applications of sediment transport are critical for understanding and managing sediment dynamics in coastal environments. The FUNWAVE-TVD model, a numerical Boussinesq wave model, has been instrumental in analyzing sediment transport and morphology evolution in various coastal engineering contexts. This model is particularly adept at handling rapidly varying terrains and steep slopes in the surf zone, providing significant insights into sediment transport dynamics during large-scale wave flume experiments.[250.1] Recent advancements in high-performance computing have made phase-resolving, Boussinesq-type numerical wave models like FUNWAVE-TVD more practical for addressing nearshore coastal wave processes.[262.1] This model has been widely adopted across scientific and engineering disciplines, facilitating the integration of traditional coastal engineering practices with high-fidelity numerical modeling. Such integration is essential for rapid screening of coastal structure alternatives during the planning, engineering, and design phases of projects.[263.1] Moreover, the application of machine learning (ML) techniques in sediment transport modeling has emerged as a promising approach to enhance the accuracy of predictions. By utilizing available domain knowledge and modern regression techniques, ML can help reduce inaccuracies in sediment transport models, which often stem from the complexities of hydrological processes.[254.1] For instance, a study comparing the performance of a sediment rating curve model with an ML algorithm (XGBoost) highlighted the potential of ML to improve predictions of suspended sediment transport rates under varying hydrological conditions.[255.1] The integration of remote sensing data into sediment transport studies further enhances modeling accuracy. By assimilating remotely sensed suspended sediment data into numerical models, researchers can better capture the dynamics of sediment transport in both inland and coastal waters.[276.1] This approach not only supplements direct measurements, which can be logistically and financially burdensome [277.1], but also allows for a more comprehensive understanding of sediment dynamics in complex environments.Environmental Management and Restoration
Sediment transport plays a crucial role in environmental management and restoration, particularly concerning water quality and ecosystem health. Excessive sediment loads can lead to significant degradation of water quality, impacting both human and environmental health through various mechanisms that alter the physical, chemical, and biological characteristics of aquatic environments.[257.1] To mitigate these negative effects, best management practices are essential across sectors such as agriculture, construction, and urban development. These practices aim to minimize sediment runoff and restore degraded areas, thereby ensuring the health of aquatic ecosystems for future generations.[257.1] Innovative strategies have been developed to address the challenges posed by sediment transport in water treatment processes. For instance, sediment control measures, including sediment ponds and settling basins, can effectively remove suspended particles before they are discharged into water bodies.[256.1] Additionally, the field of sediment remediation has evolved to focus not only on contaminant removal but also on ecological restoration, emphasizing the recovery of resources from sediments as a means of promoting environmental stewardship and sustainability.[259.1] Technologies such as dredging, electrokinetic separation, chemical stabilization, and phytoremediation are employed to treat contaminated sediments, highlighting the importance of integrating ecological perspectives into sediment management practices.[271.1] Furthermore, understanding the interactions between different sediment transport processes—such as suspension, saltation, and bedload movement—is vital for effective coastal ecosystem management. These processes influence sediment mobility in response to waves and currents, which in turn affects the morphodynamics of coastal environments.[267.1] The dynamics of sediment transport can lead to the formation of small-scale bed forms and impact the overall health of coastal ecosystems.[269.1] Therefore, a comprehensive approach that considers these interactions is essential for maintaining the integrity of aquatic habitats and ensuring the sustainability of water resources.[268.1]In this section:
References
[1] Earth Surface Sediment Transport - an overview - ScienceDirect — Abstract Sediment transport is the mechanism that translates the work of hydrodynamic processes into morphological change. Without a transport of sediment, there would be no beaches. Significant progress has been made on the topic of non-cohesive sediment transport in wave-dominated settings since the first publication of this chapter. This especially applies to the study of sheet flow, and
[2] Sediment Transport and Deposition - Geology Science — Sediment Transport and Deposition » Geology Science Home Geology Branches Sedimentology Sediment Transport and Deposition Sediment transport and deposition are key processes in sedimentology that govern the formation of sedimentary rocks. Once sediment is transported, it can be deposited in a wide range of environments, including river channels, lakes, deltas, beaches, and deep marine basins. The study of sediment transport and deposition is critical for understanding the formation of sedimentary rocks and the environments in which they were deposited. This type of sediment transport is important in rivers, streams, and other waterways where sand and other small particles are moved along the bottom by flowing water.
[3] Sediment Transport | SpringerLink — Sediment Transport | SpringerLink Sediment Transport Importance of sediment transport Sediment transport has been studied for centuries and remains a challenging area of research for earth and marine scientists. Sediment transport: new approach and analysis. Journal of Hydraulic Engineering, 123(2), 149–152. The bed load function of sediment transportation in open channels. M.R.D. Sediment Series No. 8. Hydraulics of Sediment Transport. Journal of the Hydraulics Division, ASCE, 96(HY3), 619–632. Coastal Bottom Boundary Layers and Sediment Transport. Journal of Hydraulic Research, 9, 91–113. Journal of the Hydraulics Division American Society of Civil Engineers, 105, 1185–1201. Journal of Hydraulic Engineering, 117(11), 1591–1592. Journal of Hydraulic Engineering, 110(11), 1613–1641. Principles of sediment transport in rivers, estuaries and coastal seas, 7.41–7.43 (stochastic predictor), Oldemarkt: Aqua Publications. Mechanics of Sediment Transport. Sediment Transport.
[4] Sediment transport | PPT - SlideShare — This document summarizes key concepts related to sediment transport in rivers and oceans. It defines terms like viscosity, boundary layers, shear stress, and Shields stress. It explains how sediment size is characterized and settles according to Stokes' law. The structure of bottom boundary layers is described, including the log layer where
[6] PDF — channel systems are common methods used to provide flood control, navigation, water supply, sediment management, irrigation, recreation, and hydropower. ... the channels are efficient conveyors of sediment and the sediment delivery processes are much different than those studied by Trimble and others. ... particularly when sediment transport is
[7] Flood modeling and fluvial dynamics: A scoping review on the role of ... — Past investigations have demonstrated a heightened concentration of sediment transport during flood seasons, emphasizing the necessity of integrating sediment dynamics into flood risk management strategies (Apel et al., 2016; Mao, 2018). While this comprehensive review (Vázquez-Tarrío et al., 2023) has addressed the impact of sediment transport on flood events, the current study endeavors to delve into aspects that have received less attention in previous studies. Although these knowledge gaps introduce significant uncertainty into all computational models, it's essential to acknowledge that the impacts of floods on river morphology and sediment dynamics have been thoroughly documented (Gervasi et al., 2021; Pasternack and Wyrick, 2017; Weber and Pasternack, 2017).
[8] Sediment management strategies - Hydropower — 1. Reduce sediment yield from upstream. The initial stage in sediment management is reducing the amount of sediment entering the reservoir from the contributing catchment. This can be done by minimising sediment production in the catchment through erosion control methods and trapping sediment before it reaches the reservoir.
[9] Flood modeling and fluvial dynamics: A scoping review on the role of ... — Guo et al. (2018) presented an innovative flood modeling framework, departing from conventional approaches, by introducing a hydrological risk model that integrates flood control and sediment transport considerations. The study focused on two catchments on the Loess plateau in China: the upper catchments of the Xianyang and Huaxian stations.
[15] Effects of ambient currents and waves on gravity-driven sediment ... — The maximum sustained rate of gravity-induced sediment transport occurs when ambient currents are strong, but the supply of easily suspended sediment exceeds the resuspension capacity of the ambient currents. Feedback then leads to values of the gradient Richardson number (Ri) within the flow that are near the critical value of 1/4. This
[16] Non-cohesive and cohesive sediment transport due to tidal currents and ... — The suspended sediment concentration and sediment transport in estuarine and coastal regions are mainly dominated by the combined action of waves and currents (Wang, 1989; Lee and Dade, 2004; Franz et al., 2017).Indeed, the hydrodynamic conditions control and affect sediment resuspension, mixing, and transport processes.
[44] (PDF) Sediment Transport - ResearchGate — Sediment transport is a geological process involved in the morphological evolution of the surface of the earth. Fundamental and applied aspects concerning this process are of interest for human
[45] The Physics of Sediment Transport Initiation, Cessation, and ... — 1 Introduction. When an erodible sediment bed is subjected to a shearing flow of a Newtonian fluid, such as air or water, bed particles may be entrained (i.e., set into motion) by the action of flow forces and then transported by the flow, initiating a process known as sediment transport.The critical conditions that are required for the initiation of sediment transport have been studied for
[46] Mechanics of Sediment Transport: Back Matter - ASCE Library — CONCLUDING REMARKS The modem study of the mechanics of sediment transport has been going on for more than 70 years since its commencement in the 1920s. The results of research introduced in the text cover a broad scope and convey the fruits of the many related studies. A review of the long history of development indicates the credits that are due for the progress and achievements made so far
[47] Sedimentology, history | SpringerLink — The fifth major change was that experimental work on sediment transport and bed forms, carried out largely by engineers since the 1930s, was reintroduced to geologists at an SEPM symposium on sedimentary structures (Middleton, 1965; and Middleton, 1977 for later developments).
[48] Sediment Transport and Deposition - Geology Science — Sediment Transport and Deposition » Geology Science Home Geology Branches Sedimentology Sediment Transport and Deposition Sediment transport and deposition are key processes in sedimentology that govern the formation of sedimentary rocks. Once sediment is transported, it can be deposited in a wide range of environments, including river channels, lakes, deltas, beaches, and deep marine basins. The study of sediment transport and deposition is critical for understanding the formation of sedimentary rocks and the environments in which they were deposited. This type of sediment transport is important in rivers, streams, and other waterways where sand and other small particles are moved along the bottom by flowing water.
[55] The delicate balance of river sediments | Science — Sediments play a pivotal role in defining river morphology on small scales (such as riverine habitats) and large scales (such as river deltas), as well as in shaping river ecosystems by transporting nutrients and pollutants. Most anthropogenic land use often increases sediment erosion and transport, whereas dam building decreases sediment
[57] Sediment Transport | MDPI Books — This Special Issue presents a collection of recent advancements in sediment transport research and hydraulic engineering that contribute to filling the knowledge gap in morphodynamic processes at different scales, with an outlook towards innovative river engineering approaches, monitoring systems, available technologies, and management practices tackling rapidly changing environmental conditions.
[58] Sediment Transport - Recent Advances - IntechOpen — The effective governance and administration of many aquatic environments requires a detailed understanding of sediment transport and behavioral dynamics. This has both environmental and economic implications, especially where there is any anthropogenic involvement. Sediment Transport - Recent Advances examines sediment transport-related issues in estuarial, coastal, or freshwater
[59] Recent Advancements in Sediment Transport Modelling in Reservoirs — Recent Advancements in Sediment Transport Modelling in Reservoirs[v1] | Preprints.org An overview of reservoir sedimentation processes, and models of reservoir and shallow water bodies is provided in this article. Modeling of Sediment Transport and Deposition in Reservoirs Shabani, A.; Woznicki, S.A.; Mehaffey, M.; Butcher, J.; Wool, T.A.; Whung, P.Y. A coupled hydrodynamic (HEC-RAS 2D) and water quality model (WASP) for simulating flood-induced soil, sediment, and contaminant transport. Teeter, A.M.; Johnson, B.H.; Berger, C.; Stelling, G.; Scheffner, N.W.; Garcia, M.H.; Parchure, T.M. n.d. Hydrodynamic and sediment transport modeling with emphasis on shallow-water, vegetated areas (lakes, reservoirs, estuaries and lagoons). J. M.; 2002, User’s Manual for GSTARS3 (Generalized Sediment Transport model for Alluvial River Simulation version 3.0), U.S. Bureau of Reclamation Technical Service Center, Denver, Colorado.
[87] Sediment Transport - an overview | ScienceDirect Topics — Plutonium isotopes have proven to be a good tool for studying the different parameters of sediment transport from entry into the water stream to permanent deposition (Liu et al., 2020; Hao et al., 2018; Wang et al., 2020; Yamada et al., 2020). Plutonium isotopes are used as fingerprints of sediments and are widely applied in studies of sediment transport, dynamics and origin (Yamada and Zheng, 2021), sediment sources in marine and fluvial environments (Zebracki et al., 2015; Wang et al., 2021a; Zhang et al., 2020), anthropogenic impact (Corcho-Alvarado et al., 2022; Al-Qasmi et al., 2018; Jaegler et al., 2019).
[91] Effect of sediment transport on flow characteristics in non-prismatic ... — No considerable change was noted for larger particles. Sediment mass discharge had a considerable effect on flow velocity. As sediment mass discharge increased, flow velocity decreased. The flow velocity at the channel outlet was 0.52 and 0.50 m/s corresponding to sediment mass discharge of 5.19 kg/s and 15.56 kg/s, respectively.
[92] Sediment transport during flood event: a review - Springer — Flow unsteadiness in flood events has a significant effect on the structure of the flow field and motion of sediment particles, thereby affecting dispersion of pollutants and river ecology. The aim of the present article was to evaluate state-of-the-art research efforts concerning flow characteristics and sediment transport in unsteady flow condition. The paper is organized in four sections
[93] Impact of Stem Size on Turbulence and Sediment Resuspension Under ... — The vegetation-generated turbulence dominated the total turbulence inside canopies. For the same sediment size, the critical turbulent kinetic energy at which resuspension was initiated was the same for both vegetated and bare beds, which resulted in a critical velocity that decreased with increasing solid volume fraction.
[96] Influence of Bed-Load Transport on Flow Resistance of Step-Pool Channels — This study investigates the influence of bed-load transport on flow resistance and bed stability in steep step-pool channels. A total of 86 flume experiments was performed. Stable step-pool sequences were formed with increasing discharge under clear-water conditions.
[97] Evaluation of bedload transport predictions using flow resistance ... — Steep mountain streams typically feature macro-roughness elements like boulders, step-pool sequences, and a varying channel width. Flow resistance because of such roughness elements appears to be an important control on bedload transport rates. Many commonly used bedload transport equations overestimate the transport in steep streams by orders of magnitude.
[130] How Does Sediment Affect Water Quality? - The Environmental Literacy ... — While a natural component of rivers, lakes, and oceans, excessive sediment loads can trigger a cascade of negative impacts on water quality, threatening both human and environmental health. Sediment affects water quality through a multitude of complex mechanisms, impacting the physical, chemical, and biological characteristics of aquatic environments. The energy source for an aquatic ecosystem is directly impacted by excess sediment. Sediment is a crucial component of our aquatic ecosystems, but excess sediment can dramatically impair water quality, negatively affecting physical, chemical, and biological processes. By implementing best management practices across agriculture, construction, and urban development, as well as restoring degraded areas, we can minimize the negative effects of excessive sediment on our vital water resources, ensuring the health of aquatic ecosystems for generations to come.
[131] River Sediments Explained: Formation, Transport and Human Impact — The river Ghaghra meanders through the plains of Uttar Pradesh, with a dynamic interplay of water and sediments.Image sourced from Google Maps The sediment-rich waters of the Brahmaputra, a river infamous for its devastating floods.Image sourced from Google Maps The Machhu river forms a delta as it meets the sea on the Gujarat coast, creating a fan of sediment deposits.Image sourced from Google Maps. Human activities on rivers such as the construction of dams and barrages, sand mining, hampers the flow of sediments, which affects the rivers’ energy and flow, and consequently its floodplain. Madikheda dam on River Sindh in Madhya Pradesh holds a large volume of water and sediment, and deprives downstream stretches of a free flowing river.Image credits - Aishani Goswami
[132] Sediment and Aquatic Habitat in River Systems — As the grain size distribution of the bed load approaches that of the bed material, the number of benthic species declines. Sediments provide cover and spawning sites for fish and habitat for fish food organisms. Sediment also serves as an indirect indicator of fish‐habitat quality when it provides a temporal integration of depth and velocity.
[134] Sediment and Nutrient Trapping by River Dams: A Critical ... - Springer — In 2006–2021, there are 1385 publications in total, including 1318 articles and 23 reviews; (ii) dams can interrupt river connectivity and trap sediment and nutrients in reservoirs, greatly deceasing sediment and nutrient loads to coastal oceans; (iii) sediment and nutrient trapping by dams has caused a series of ecological impacts, including reservoir capacity loss, river channel erosion, river delta land loss, reservoir eutrophication, and massive greenhouse gas emissions. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
[136] Assessment of reservoir trapping efficiency and hydropower production ... — Addressing the impacts of sediment alteration is crucial, and one approach is to incorporate environmental flows (e-flows) into dam operations . E-flows involve maintaining minimum water and sediment discharge downstream of dams to mimic natural flow patterns and support the ecological health of river systems [ 21 ].
[138] Sediment transport under increasing anthropogenic stress: Regime shifts ... — Ecosystems respond to climatic and anthropogenic forcings with regime shifts and reorganizations of their system structures. In river basins, changes in sediment transport can have cascading effects that cause ecosystem regime shifts. The Yellow River, once the world's most sediment-rich river, has experienced dramatic regime shifts. Although recent intervention has returned sediment
[156] Shifted sediment-transport regimes by climate change and ... - AAAS — Climate change and cryosphere degradation have remarkably affected riverine water and sediment fluxes from polar and high-mountain regions, with varying effects seasonally and geographically (1-3).However, the responses of seasonal dynamics and regime shifts in sediment transport remain largely understudied, limited by the lack of long-term (e.g., decadal) and fine-scale (e.g., monthly to
[157] Shifted sediment-transport regimes by climate change and amplified ... — Climate change affects cryosphere-fed rivers and alters seasonal sediment dynamics, affecting cyclical fluvial material supply and year-round water-food-energy provisions to downstream communities. Here, we demonstrate seasonal sediment-transport regime shifts from the 1960s to 2000s in four cryosphere-fed rivers characterized by glacial, nival, pluvial, and mixed regimes, respectively. Spring see
[158] Altered flow and sediment transport impacts on the ecosystems of ... — The impacts of global climate change on precipitation and sediment transport have been well documented (Darby et al., 2016; Hirmas et al., 2018); however, the time scale of climate change is typically lengthy, and its ecological impacts are cumulative. The impact of human activities on rivers has increased with the advancement of hydraulic
[159] Climate change as main driver of centennial decline in river sediment ... — 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
[160] Climate change impacts on streamflow, sediment load and carbon fluxes ... — Climate change impacts on streamflow, sediment load and carbon fluxes in the Lena River delta - ScienceDirect Climate change impacts on streamflow, sediment load and carbon fluxes in the Lena River delta Based on analyses of correlations between various hydroclimatic drivers and sediment concentration changes across particular distributaries of the Lena Delta extracted from Landsat datasets, bank degradation driven by thermal erosional processes (which are in turn related to air and soil temperature increases) is proved to be the primary factor of the sediment regime in the delta. We conclude that the Lena Delta can be recognized as the global hot spot in terms of the hydrological consequences of climate change, which is altering sediment regimes, stream hydromorphology and carbon transport.
[177] The Environmental Impact of Dike Systems on Local Ecosystems — Dikes also affect sediment transport dynamics. Rivers naturally carry sediment downstream, which supports the health of riverine ecosystems and replenishes coastal areas. When dikes are implemented, sedimentation patterns can change significantly. Reduced sediment flow can lead to erosion downstream and increased vulnerability to other forms of
[178] Understanding Hydrology: The Science Behind Dikes — Dike construction can disrupt natural river flows and sediment transport processes. This alteration may affect local ecosystems: Habitat Fragmentation: Dikes can create barriers for wildlife movement. Sedimentation Changes: Altered sediment transport may lead to erosion downstream or sediment buildup upstream. Water Quality Concerns
[179] Impacts of Major Storage Dams on the Sediment Transport in ... - InSPIRe — From these results, the study shows that the main impact dams have on water quality are the reduction of suspended sediment load and organic carbon, and riverbed sediment grain size. These factors affect downstream benthic ecosystems by reducing habitat, decreasing desirable conditions for native species, and interrupting nutrient flow.
[180] Sustainable sediment management in reservoirs and regulated rivers ... — 1 Introduction 1.1 Reduced Sediment Loads Downstream of Dams. Dams interrupt the continuity of sediment transport through rivers systems, causing sediment to accumulate within the reservoir itself (impairing reservoir operation and decreasing storage) and depriving downstream reaches of sediments essential to maintain channel form and to support the riparian ecosystem.
[181] Sediment and Nutrient Trapping by River Dams: A Critical ... - Springer — In 2006–2021, there are 1385 publications in total, including 1318 articles and 23 reviews; (ii) dams can interrupt river connectivity and trap sediment and nutrients in reservoirs, greatly deceasing sediment and nutrient loads to coastal oceans; (iii) sediment and nutrient trapping by dams has caused a series of ecological impacts, including reservoir capacity loss, river channel erosion, river delta land loss, reservoir eutrophication, and massive greenhouse gas emissions. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
[186] Human Activities on Aquatic Ecosystems | College Board AP ... — Human impact on coral reefs. Coral reefs have been suffering damage due to a variety of factors. Sediments and fertilizers from agriculture, sewage, and urban development runoff into the ocean, suffocating corals and promoting algae growth. Destructive fishing practices like. Blast fishing or cyanide to stun and remove live fish. Overfishing harms coral ecosystems by removing key reef species
[190] Impacts of Urbanization and Development on Estuarine Ecosystems and ... — Urbanization and human-led development have increased more rapidly along shorelines and in coastal watersheds than inland regions over the past century. The result of major land use changes for both urban tracts and agriculture to serve the urban areas, as well as infrastructure development is increased runoff carrying sediments, nutrients, pollutants, pharmaceuticals, and toxins downstream to
[191] The global human impact on biodiversity - Nature — Human activities drive a wide range of environmental pressures, including habitat change, pollution and climate change, resulting in unprecedented effects on biodiversity 1,2.However, despite
[192] How Does Sediment Affect Water Quality? - The Environmental Literacy ... — While a natural component of rivers, lakes, and oceans, excessive sediment loads can trigger a cascade of negative impacts on water quality, threatening both human and environmental health. Sediment affects water quality through a multitude of complex mechanisms, impacting the physical, chemical, and biological characteristics of aquatic environments. The energy source for an aquatic ecosystem is directly impacted by excess sediment. Sediment is a crucial component of our aquatic ecosystems, but excess sediment can dramatically impair water quality, negatively affecting physical, chemical, and biological processes. By implementing best management practices across agriculture, construction, and urban development, as well as restoring degraded areas, we can minimize the negative effects of excessive sediment on our vital water resources, ensuring the health of aquatic ecosystems for generations to come.
[211] The Three Modes of Sediment Transport of Sedimentary Particles — The Three Modes of Sediment Transport of Sedimentary Particles The Three Modes of Sediment Transport of Sedimentary Particles Commonly, sediment grains larger than sand size are transported as part of the bed load in essentially continuous contact with the bed. Such a type of bed load transport is called siltation because the grains tend to move in intermittent contact with the bed. Consequently, the upward/ vertical component of the turbulent motion equals/ exceeds the down-settling velocity of particles, and the grains go into the suspension while in transportation, the particles are in continuous processes of wear and sorting as to size and maturity (textural and mineralogical). The Three Modes of Sediment Transport of Sedimentary Particles Dhaka – 1000, BD student@gelogia.com
[213] Sediment Transport - an overview | ScienceDirect Topics — For example, check dams and appropriate watershed management practices can reduce surface runoff, soil erosion and suspended solids concentration by affecting the relation between surface runoff and watershed sediment transport (Bai et al., 2020; Yan et al., 2015). Following the idea of retaining the physics involved in sediment dynamics, Hudson and Sweby studied the influence of steady and unsteady approaches in the mathematical model when computing free surface flows considering bed-load transport. It is generally considered that the presence of vegetation is associated with increased sedimentation of suspended particles in rivers, flumes and agricultural channels (Abt et al., 1994; Cotton et al., 2006; López and García, 1998) and decreased bed-load transport (Kothyari et al., 2009).
[219] Turbulent flow mechanisms in meandering channels with sediment transport — The present study examines the role of turbulent flow in the development of sediment transport by applying a discharge to maintain mobile bed conditions with non-uniform sand bed material. The interaction of flow in a river with the sediment can generate bed aggradation and degradation processes, which are relevant in river management engineering.
[250] A coupled model for sediment transport dynamics and prediction of ... — Taking advantage of FUNWAVE-TVD model's capacity to employ rapidly varying terrains and steep slopes in the surf zone, this study provides significant insights into the sediment transport dynamics in a variety of coastal engineering applications. Sediment transport and morphology evolution were analyzed for the case of large-scale wave flumes
[254] Sediment Transport Modeling through Machine Learning Methods: Review of ... — Effective modeling of sediment load components remains a challenging task since their complicated hydrological procedure. On this account, this chapter aims to appraise the role of machine learning methods in modeling the sediment transport and review the different strategies for increasing the level of modeling accuracy.
[255] Using Machine Learning to Predict Suspended Sediment Transport under ... — The specific objectives of the study are as follows: (i) to evaluate the performance of the sediment rating curve model compared with a machine learning algorithm (i.e., XGBoost) based on historical data; and (ii) to evaluate potential future changes in hydrological processes and suspended sediment transport rates using the combined rainfall‒runoff and machine learning model up to the year 2100 based on the three representative concentration pathways (RCPs) (i.e., RCP2.6, RCP4.5, and RCP8.5). There are several reasons for the slightly lower performance of the selected models (Efthimiou 2024): (i) sediment transport processes can vary over time due to seasonal changes (e.g., influence of vegetation) or extreme weather events (e.g., local flash floods in sub-catchments) with intensive sediment transport on a subdaily time step, ii) there is potential for human activities (e.g., water works in the riverbed) during low-flow conditions, iii) there is potential uncertainty in the relationship between turbidity and suspended sediment concentration (Jastram et al.
[256] PDF — 3. Water Quality Degradation: Problem: Increased turbidity, along with the release of contaminants from dredged materials, can negatively affect water quality. Mitigation: Implementing sediment control measures, such as sediment ponds or settling basins, can help remove suspended particles before discharge. Additionally, thorough testing
[257] How Does Sediment Affect Water Quality? - The Environmental Literacy ... — While a natural component of rivers, lakes, and oceans, excessive sediment loads can trigger a cascade of negative impacts on water quality, threatening both human and environmental health. Sediment affects water quality through a multitude of complex mechanisms, impacting the physical, chemical, and biological characteristics of aquatic environments. The energy source for an aquatic ecosystem is directly impacted by excess sediment. Sediment is a crucial component of our aquatic ecosystems, but excess sediment can dramatically impair water quality, negatively affecting physical, chemical, and biological processes. By implementing best management practices across agriculture, construction, and urban development, as well as restoring degraded areas, we can minimize the negative effects of excessive sediment on our vital water resources, ensuring the health of aquatic ecosystems for generations to come.
[259] Towards sustainable futures: A review of sediment remediation and ... — The complex interaction between sediment properties and environmental factors significantly influences the deposition, retention, and ultimate destiny of contaminants, thereby affecting their bioavailability and toxicity (Go et al., 2009). The field of sediment remediation has evolved from a primary focus on contaminant removal to encompassing a broader ecological perspective (Bianco et al., 2023; Pringault et al., 2010). The recovery of resources from sediments has become a critical focus, aligning with the dual goals of environmental stewardship and resource sustainability (Liu et al., 2023b; Mehmood et al., 2023). The existing technology in treating Cd polluted sediment mainly includes dredging, electrokinetic separation, chemical stabilization and phytoremediation (Yang et al., 2024).
[262] FUNWAVE-TVD testbed : analytical, laboratory, and field cases for ... - HPC — Over the last couple of decades, advancements in high-performance computing have allowed phase-resolving, Boussinesq-type numerical wave models to be more practical in addressing nearshore coastal wave processes. As such, the open-source Fully Nonlinear Wave model-Total Variation Diminishing (FUNWAVE-TVD) numerical wave model has become more ubiquitous across all scientific and engineering
[263] Wave Response with Coastal Structures — FUNWAVE Documentation — Wave Response with Coastal Structures¶. Ongoing work with the U.S. Army Engineer Research and Development Center (ERDC) has focused on connecting traditional coastal engineering practices with high-fidelity numerical modeling for the benefit of providing rapid screening of coastal structure alternatives in the planning, engineering, and design phase of a new or existing project.
[267] Observations of Bedform Migration and Bedload Sediment Transport in ... — 1 Introduction. Coastal morphodynamics is driven by sediment mobility in response to waves, currents, and combined wave-current flows. Sediment transport is broadly considered in two classifications, bedload and suspended load transport (van Rijn, 1993).Numerous studies have shown that the small-scale morphologic change is correlated to the bedload transport (Aagaard et al., 2001; Amos et al
[268] The nature of saltation and of 'bed-load' transport in water — The theory, which is largely confirmed by these and other earlier experiments, indicates that suspension by fluid turbulence of mineral solids larger than those of medium sands does not become appreciable until the bed shear stress is increased to a value exceeding 12 times its threshold value for the bed material considered.
[269] Relative Contributions of Bed Load and Suspended Load to Sediment ... — Sediment grain saltation occurs in lower energy flow conditions (0.05 < θ < 0.50) and typically results in the development of small-scale bed forms (e.g., ripples). Under strong bed shear stress and strong pressure gradients, typical of skewed-asymmetric waves in the surf zone, small-scale bed forms are planed out with the onset of sheet flow
[271] Towards sustainable futures: A review of sediment remediation and ... — The complex interaction between sediment properties and environmental factors significantly influences the deposition, retention, and ultimate destiny of contaminants, thereby affecting their bioavailability and toxicity (Go et al., 2009). The field of sediment remediation has evolved from a primary focus on contaminant removal to encompassing a broader ecological perspective (Bianco et al., 2023; Pringault et al., 2010). The recovery of resources from sediments has become a critical focus, aligning with the dual goals of environmental stewardship and resource sustainability (Liu et al., 2023b; Mehmood et al., 2023). The existing technology in treating Cd polluted sediment mainly includes dredging, electrokinetic separation, chemical stabilization and phytoremediation (Yang et al., 2024).
[276] Assimilation of remote sensing observations into a sediment transport ... — Numerical models are important tools that are used in studies of sediment dynamics in inland and coastal waters, and these models can now benefit from the use of integrated remote sensing observations. This study explores a scheme for assimilating remotely sensed suspended sediment (from charge-coupled device (CCD) images obtained from the Huanjing (HJ) satellite) into a two-dimensional
[277] Toward Improved Accuracy of Remote Sensing Approaches for Quantifying ... — Because of the high logistical and financial costs of direct measurements of riverine suspended sediment, remote sensing is increasingly used to supplement the direct-observation record. The accuracy of this method is poorly constrained, and its potential as a tool for understanding river sediment transport is thus limited.