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The present paper aimed to assess the sediment distribution pattern, mode of transport, and its interaction with hydrodynamic and topographic conditions at different depths and regions along the east coast of India. About 900 surficial sediment samples were collected and analysed on a monthly basis for the Chennai coastal region at 32 stations from 2013 to 2015. The study region is classified into four types, such as beach, inlet, 5 m, and 10 m depth. Sediment textural and grain size trend analyses were conducted to achieve the objectives. Sediment characteristics for the region were recorded as sandy, equally dominated by unimodal and bimodal at the beach, while unimodal at shallow depths (5 and 15 m). The sediments were medium sand to coarse sand at the beach, mostly fine followed by medium at 5 and 15 m depths. The sediment sorting is dominated by moderately well-sorted sediments; the skewness of beach sediments was negative, while nearshore sediments were found positive; average kurtosis values of sediments were noticed to be mesokurtic. The CM plot depicts that the sediments were mostly derived by tractive current, and the modes of transport are "bottom suspension and rolling" and "graded suspension no rolling" at beach locations and shallow water depths, respectively. The GSTA analysis reveals the annual average sediment transport pattern is northerly. The numerical hydrodynamic study confirms the GSTA and CM plot analysis. The study reveals a stable sedimentary environment south of the Chennai port and instability in the northern part. The study includes large spatiotemporal nearshore sediment data with hydrodynamic conditions, immensely helpful to coastal stakeholders and researchers. [ABSTRACT FROM AUTHOR]

Guru Prasath, J.; Sannasiraj, S.A., and Chandramohan, P., 2024. Nearshore morphological changes due to severe cyclonic storm activity along the east coast of India. Journal of Coastal Research, 40(4), 696–713. Charlotte (North Carolina), ISSN 0749-0208. Nearshore waves, wind, and tidal current mobilize seabed sediments; sort, transport, and redistribute the sediments; and modify the nearshore seabed morphology. Waves play a dominant role in morphological changes among winds, waves, and tidal currents. The nearshore wave breaking induces the initiation of sediment movement, and the associated alongshore current transports a large volume of sediments that tend to either accrete toward or erode from the beach face and seabed. Sediment transport rate in the nearshore waters during cyclones is higher than that under normal conditions. The measured changes due to Cyclone Nivar in November 2020 in the nearshore morphology along the Mahabalipuram coast are examined to understand the response of nearshore morphology to cyclonic wave-induced forcing. The beach-profile measurements across 10 transects at 100 m spacing covering about 1000 m along the coast were measured before and after the passage of Cyclone Nivar as a part of the present field study. The evolving beach profiles during Cyclone Nivar were simulated using the storm-induced beach change (SBEACH) model, which is a cross-shore profile evolution model. The changes due to berm erosion and deposition of nearshore sand bars have been compared from field measurements data and model prediction. The calibrated model was then used to simulate the beach profile response at two other locations along the cyclone-affected coastline to examine the shoreline impact. The calibrated model can be used along the coast to understand the poststorm profiles of the beach with reasonable accuracy. [ABSTRACT FROM AUTHOR]

Abstract: Tidal flats are dynamic coastal ecosystems continually reshaped by natural processes and human activities. This study investigates the application of Empirical Orthogonal Function (EOF) analysis to the long-term profile evolution of tidal flats along the Jiansan Bend of the Qiantang River Estuary, China. By applying EOF analysis to profiles observed from 1984 to 2023, this study identifies dominant modes of variability and their spatial and temporal characteristics, offering insights into the complex sediment transport and morphological evolution processes. EOF analysis helps unravel the complex interactions between natural and anthropogenic factors shaping tidal flats, with the first three eigenfunctions accounting for over 90% of the observed variance. The first spatial eigenfunction captures the primary trend, while the subsequent two eigenfunctions reveal secondary and tertiary modes of variability. A conceptual model developed in this study elucidates the interplay between hydrodynamic forces and morphological changes, highlighting the rotation and oscillation of tidal flat profiles in response to seasonal variations in hydrological conditions. The findings emphasize the effectiveness of EOF analysis in capturing significant geomorphological processes and underscore its potential in enhancing the understanding of tidal flat dynamics, thereby informing more effective management and conservation strategies for these critical coastal environments. [ABSTRACT FROM AUTHOR]

The University of Southern Mississippi has developed the coastal CUBEnet environment. Coastal CUBEnet is a high-resolution, coastal ocean sensor, modeling, and data sharing web-based network that provides the environmental intelligence needed to support the complex modeling of the interlinked processes in the northern Gulf of Mexico. With near-real time data delivery via a common infrastructure, CUBEnet uses state of the art sensors to provide a set of networked measurements systems, visualization tools, and model developments to gain an understanding of the Gulf of Mexico's marine environments. CUBEnet is also a mechanism for improved human engagement with Gulf of Mexico resources and provides stake holders with the data needed to make informed coastal, environmental, and economic decisions. The Coastal CUBEnet's data environment utilizes both stationary and uncrewed mobile systems and high-resolution distributed sensors to create a networked platform across the northern coastal Gulf of Mexico. CUBEnet's modeling environment has developed an implementation of The Coupled Ocean Atmosphere Wave Sediment Transport (COAWST) Model for the Mississippi Bight region that has been applied to investigate shore to shelf advective exchange processes, and their influence on coastal water quality conditions that support the region's prolific marine ecosystem. CUBEnet's modeling environment provides prototype modeling applications that are supported by real-time observations of key coastal environmental variables. CUBEnet's Web accessible visualization tools provide parameter fields and vertical profiles from hydrodynamic models and field observations. Nowcasts and forecast results are available for the Eastern LA coastline, MS coastline, Mobile Bay, and the West coast of Florida. [ABSTRACT FROM AUTHOR]

The sediment transport along a coastal zone of Thermaikos Bay and the interaction with the coastline were studied in the present research. This study concerns the greater basin of an existing breakwater, for which the sand transport during the time periods 1950–1968 and 2009–2017, before and after the construction of the breakwater, were examined. The breakwater led to sand accumulation behind it, causing the well-known phenomenon of salient. It was revealed that climate change, in terms of wind conditions, significantly affected sediment transport; more specifically, the sand transport during 2009–2017 not only decreased significantly, but also changed its direction, in relation to 1950–1968. Based on the information obtained, technical interventions are proposed for the interception of sediment transport and the consequent accumulation of sand behind the breakwater. [ABSTRACT FROM AUTHOR]

Coastal erosion poses significant challenges to shoreline management, exacerbated by rising sea levels and changing climate patterns. This study investigates the influence of gap spacing between semicircular coastal defence structures on shoreline dynamics during storm events. The innovative design of these structures aims to induce a drift reversal of prevalent sediment transport while avoiding interruption of alongshore sediment drift, thus protecting the beach. Three different gap spacings, ranging from 152 m to 304 m, were analysed using the XBeach numerical model, focusing on storm morphodynamic behaviour. Methodologically, hydrodynamic and morphodynamic analyses were conducted to understand variations in significant wave heights adjacent to the structures, in accretion and erosion volumes, and changes in bed level under storm conditions. The study aims to elucidate the complex interaction between engineered coastal protection solutions and natural coastal processes, providing practical insights for coastal management practices. Results indicate that installing semicircular coastal defence structures influences sediment dynamics during storm events, effectively protecting stretches of the coast at risk. Optimal gap spacing between structures is crucial to mitigating coastal erosion and enhancing sediment accumulation, offering a sustainable shoreline protection approach. The findings underscore the importance of balanced location selection to optimize protection benefits while minimizing adverse morphological effects. Overall, this research contributes to advancing knowledge of hydro-morphological phenomena essential for effective coastal engineering and informs the design and implementation of more sustainable coastal protection strategies in the face of increasing coastal erosion and sea level rise challenges. [ABSTRACT FROM AUTHOR]

The Thermaikos Gulf (TG) is a semi-enclosed, river-influenced, marine system situated in the eastern Mediterranean Sea, sustaining both urban coastal regions and ecologically preserved natural areas. Facing a plethora of environmental and anthropogenic pressures, the TG serves as a critical nexus where human activities intersect with marine ecosystems. The quality and health of the TG's marine environment are tightly linked to the socioeconomic activities of the coastal communities comprising approximately 1.5 million inhabitants. The main features of the TG's environmental dynamics and ecological status have been scrutinized by dedicated research endeavors during the last 50 years. This review synthesizes the seminal findings of these investigations, offering an evaluation of their contribution to research, their present collective impact, and their trajectory toward the future. A severe deterioration of the TG's environmental quality was detected in the 1970s and 1980s when the treatment of urban wastewater was completely absent. A steady trend of recovery was observed after the 1990s; however, so far, the goal of a "good environmental state" mandated by national legislation and European directives has not been achieved. A clear reduction in research was detected after 2010, associated with the recession of the Greek economy, following the "golden period" for research in the TG from the mid-1990s until the late 2000s. The most important research gaps and uncertainties are discussed, while specific targeted recommendations for the improvement of monitoring and understanding of the physical, biochemical, and ecological state of the gulf are provided: (i) increase in permanent observational stations (temporally and spatially); (ii) inclusion of all major environmental parameters; (iii) monitoring of the quantity and quality of all land-originated freshwater discharges; (iv) monitoring and management of important aspects of the marine environment that have received minimal attention in the past (e.g., coastal erosion, plastic pollution); (v) development of accurate prediction tools (e.g., numerical techniques) to support first-level responders and efficient management; (vi) establishment of a supervising public entity that would support the holistic overview and management of the entire TG. These suggestions are directed at overcoming the existing uncertainties in the knowledge of the TG, safeguarding its ecological integrity and its role as a crucial link to marine biodiversity and sustainability in the Mediterranean basin. [ABSTRACT FROM AUTHOR]

Wave-induced currents play a critical role in coastal dynamics, influencing sediment transport and shaping bottom topography. Traditionally, long- and cross-shore currents in coastal zones were analyzed independently, often with two-dimensional models for longshore currents and undertow being used. The introduction of quasi-three-dimensional models marked a significant advancement toward a more holistic understanding. Despite recent proposals for fully three-dimensional models, none have achieved widespread acceptance, primarily due to challenges in accurately capturing depth-dependent radiation stress. This paper presents an innovative analytical model advocating for comprehensive three-dimensional approaches in coastal hydrodynamics. The model, based on novel simplification rules, refines relationships governing turbulent stress tensors and provides valuable insights into wave-induced stresses. It offers analytical solutions for both homogeneous and general coastal zones, laying the foundation for future advancements in numerical modeling techniques. [ABSTRACT FROM AUTHOR]

One of the most beautiful beaches in Northern Vietnam, Nhat Le, has recently experienced severe erosion as a result of the ensemble interaction of natural factors, such as tropical cyclones, extreme weather events, and human activities. Consequently, negative impacts on tourism and social and economic development have been recorded. This paper aims to provide a deep understanding of the changes in shoreline and longshore sediment transport at Nhat Le estuary based on two modules of LITDRIFT and LITLINE of the LITPACK software package combined with geospatial analysis. The rate of change statistics is calculated using the Digital Shoreline Analysis System (DSAS) from 30-year multi-temporal satellite data (1989-2019) for multiple historical shoreline positions. The Module of LITDRIFT is employed to estimate sediment transport and the shoreline position calculated from the LITLINE module. These data are then compared with measured topographic data and satellite images. Wave climate conditions are incorporated into the LITDRIFT module to identify the volume of sediment transport along the coast on seasonal and annual bases. The results illustrate that a mean erosion rate of about 2 m per year was observed in the southern sandspit of Nhat Le from 1989 to 2019. This rate reaches 4.5 m per year during 2009-2019. [ABSTRACT FROM AUTHOR]

This paper presents a review of cross-shore sediment transport for non-cohesive sediments in the coastal zone. The principles of sediment incipient motion are introduced. Formulations for the estimation of bedload transport are presented, for currents and combined waves and current flows. A method to consider the effect of sediment heterogeneity on transport, using the hiding–exposure coefficient and hindrance factor, is depicted. Total transport resulting from bedload and transport by suspension is also addressed. New research is encouraged to fill the knowledge gap on this topic. [ABSTRACT FROM AUTHOR]

Wave‐ and current‐supported gravity flows (WCSGFs) represent a primary mechanism responsible for the transport of sediment along gentle coastal and continental slopes. However, due to limited in situ measurements, the dynamic processes involved in the downslope movement of WCSGFs along such slopes remain poorly understood. Here, tripods were strategically deployed on a muddy coastal slope in central Jiangsu, China. We found that WCSGFs occurred following a wave event, particularly during tidal slack periods. In instances where WCSGF events coincide with low slack water, the observed time lags between break and toe sites align with expectations based on gravity‐driven velocities and distances, thereby corroborating the gravitationally induced sediment transport across the gently sloping coast. Comparatively, WCSGF events during high slack water were suggested to originate from the upper tidal flat of the cross‐shore profile and were unable to reach the toe site. Waves are crucial in supporting the downslope transport of WCSGFs. In addition to sustaining the cross‐shore movement of WCSGFs, currents suspend sediments from the high‐concentration layer, dispersing them into the overlying water column. This suspension helps extinguishing WCSGFs. The local slope at the toe site lacks the necessary gravitational force to propel high‐concentration layers further offshore, as evidenced by the abnormally low drag coefficient (CD) derived from the theoretical WCSGF model. Despite their short‐lived nature and limited travel distance, the WCSGFs examined in this study make a significant contribution to cross‐shore sediment transport. This study contributes to a better understanding of WCSGF dynamics and their importance in coastal sediment transport. [ABSTRACT FROM AUTHOR]

The morphological responses of two mesotidal beaches located in different coastal settings (embayed and open sandy beaches) on the northwestern Iberian coast were monitored during the winter of 2018/19. The offshore wave time series analysis is related to high-resolution topo-bathymetric measurements to explore spatial-temporal morphological variability at monthly to seasonal scales. Both locations are subjected to the North Atlantic wave climate which exhibits a pronounced seasonality. Throughout the last decade (2010–2020), significant wave heights reached values of up to Hs~9 m during winters and up to Hs~6 m during summers. On average, approximately 12 storms occurred annually in this region. The results clearly reveal divergent morphological responses and sediment transport behaviors at the upper beach and the intertidal zone during the winter for each location. In the embayed beach (Patos), sediment transport in the nearshore is governed by cross-shore processes between the beach berm and a submerged sandbar. In contrast, the open beach (Mira) showed dynamic sediment exchanges and three-dimensional morphologies alternating between accumulation and erosion zones. Overall, both beaches exhibited an erosional trend after the winter, particularly concerning berm erosion and the subaerial beach volume/shoreline retreat. This study highlights the contrasting morphodynamic response on open and embayed beaches to winter conditions, integrating both the subaerial and submerged zones. Local geological and environmental factors, as well as the coastal management strategies applied, will influence how the beach responds to winter wave events. Monitoring and understanding these responses are essential for effective coastal management and adaptation to changing climate. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Spatio-Temporal Morphodynamics of a Nourished Sandy Shore Based on LiDAR Measurements." The correction addresses errors in the original publication, specifically inappropriate citations in the Discussion section. The correction provides the correct references and clarifies the phenomenon of heightened dune erosion in the area, attributing it to long, oblique depressions in the bottom topography. The correction also discusses the ongoing coastal protection efforts on the Hel Peninsula in Poland and the causes of erosion in the area. The authors state that the scientific conclusions of the article are unaffected by the correction. [Extracted from the article]

We employed idealized numerical experiments using Delft3D to investigate how the interactions of coalescing buoyant river plumes with mangrove vegetation affect sediment transport and deposition in the coastal zone. Our model system, based on the Firth of Thames in the North Island of New Zealand, is designed to represent two mangrove-lined rivers debouching into a coastal bay. Sediment transport patterns into the three adjacent mangrove forest regions (central, western, and eastern) were assessed by quantifying the sediment fluxes over a tidal cycle. The interactions between the buoyant river plumes resulted in a coalesced river plume that flowed along the central mangrove forest between the rivers. The dominant contributors to the total sediment transport into the mangrove forests varied with both the total and the relative flows through the two rivers. When both rivers were forced with their respective flows at the 50th percentile of observed flow, the analysis of sediment transport fluxes along the central forest revealed sediment deposition inside the mangrove forests lining the river mouth nearly four times greater than in the intermediate regions along the central forest; consistent with satellite imagery of the Firth of Thames. Winds of 5 m s−1 modify the overall sediment transport patterns by deflecting the river plume in the direction of the wind. The magnitude of sediment flux is the highest (nearly 80% compared to the no-wind scenario) in the case of an easterly wind scenario as the alongshore transport is enhanced by Coriolis deflection and wind direction aligned with the alongshore flows of the larger plume. • Plume-to-plume interactions result in a coalesced river plume. • Sediment plume bulge of one river inhibits along-shore sediment transport of the other. • The presence of winds altered sediment transport patterns. [ABSTRACT FROM AUTHOR]

The formation and evolution of coastal dunes result from a complex interplay of eco-morphodynamic processes. State-of-the-art models can simulate aeolian transports and morphological dune evolution under certain conditions. However, a model combining these processes for coastal engineering applications was not yet available. This study aims to develop a predictive tool for dune development to inform coastal management decisions and interventions. The aeolian sediment transport model AeoLiS is extended with functionalities that allow for simulations of coastal landforms. The added functionalities include the effect of topographic steering on wind shear, avalanching of steep slopes and vegetation processes in the form of growth and wind shear reduction. The model is validated by simulating four distinct coastal landforms; barchan-, parabolic-, embryo dunes and blowouts. Simulations, based on real-world conditions, replicate the landform formation, migration rates and seasonal variability. • Dune shaping processes are implemented into AeoLiS enabling landform simulations. • Four distinct landform types are simulated utilizing AeoLiS. • AeoLiS replicates accurate landform shapes and dynamics under real-world conditions. • Capabilities added to AeoLiS enable its use for a range of engineering applications. [ABSTRACT FROM AUTHOR]

Sandspits at river mouths are important socio-ecological but fragile coastal ecosystems. Due to their significant role, particularly in shielding areas behind them from wave impact, sandspits are crucial, albeit they also pose challenges such as increased fluvial flooding, which often necessitates substantial engineering interventions such as artificial breaching. Here, four wave-dominated sandspits are compared to determine their common behavior. The study sites at river mouths have in common a high control of waves on longshore sediment transport leading to sandspit development; the Langue de Barbarie at the Senegal River delta, the Bouche du Roi at the mouth of the Mono River in Benin, the Mataquito River mouth in Chile, and the Pomene River mouth in Mozambique, each characterized by unique hydrodynamic conditions and geomorphologic features that influence their evolution and susceptibility to natural and anthropogenic impacts. Their cycles of opening and development, typically spanning decades, are studied by collecting 37 years of shoreline and wave reanalysis data from the Landsat and Sentinel-2 missions. It is shown that part of the morphodynamics is truly intrinsic and that climatic wave evolution drives only a small part of their evolution. A simplified model is introduced to predict the cyclic behavior of spits. The proposed model for sandspit development is based on a cyclic behavior, where newly formed spits mature and eventually break, resetting the cycle. This cyclic perception is represented as a function of time, where the elongation of the spit relative to its maximum length is modeled as a function of time and a constant wave-driven longshore sediment transport component. The model is tested at several sites with similar environmental conditions and blindly at one site with reasonable results. The present work also highlights the importance of spit evolution and the associated variability they impose on coastal downdrift and updrift, especially when considering anticipating the implementation of engineering solutions. • Cyclic behavior of sand spit lengthening. • Predicting sand spit length with a conceptual model. • Updrift and downdrift coastal impact of a sand spit lengthening. [ABSTRACT FROM AUTHOR]

Anthropogenic marine litter (AML) is a global environmental concern. One of the most conspicuous effects of AML is beach litter accumulation, the distribution of which is typically heterogenous. Little information is available on the potential effects of coastal topographic features on litter dispersal. We analysed the abundance, composition, and sources of beach litter on the East coast of England in relation to the presence of coastal groyne structures. Six beaches were surveyed in autumn and winter 2021 using the OSPAR methodology for monitoring beach litter. Litter abundance was lower on beaches with groynes present, which could infer that groynes deflect or bury AML. The presence of groynes had no significant effect on the composition/sources of beach litter. Single-use plastic packaging, fishing waste, and sewage-related debris were the largest contributors of beach litter in this region. Our findings indicate that man-made topographic features may affect marine litter dispersal and coastal accumulation. • Coastal groynes trap sediment transported by longshore drift, increasing accretion. • Litter abundance was lower on beaches with groynes compared to those without. • Topographic features may affect marine litter dispersal and coastal accumulation. • Single-use plastic, fishing waste, and sewage debris were the largest contributors. • The findings will help inform implementation of litter mitigation strategies. [ABSTRACT FROM AUTHOR]

Storms and extremely energetic events may significantly impact the form and structure of beaches, and so cause erosive processes and coastal damages. Efficient management actions require an up-to-date and accurate knowledge of beach morphological changes, with the shoreline position being a good indicator of such changes. This work proposes the use of the open-source Shoreline Analysis and Extraction Tool (SAET) software for the definition of satellite-derived shorelines (SDSs) from L8 and Sentinel-2 imagery to reveal the shoreline position changes at the beaches of the Ebro Delta, NE Spain. Spatial-temporal models (STMs) of shoreline changes enable a characterisation of how the beaches responded to the storms of 2020. In conjunction with wave data, STMs enable an analysis of the erosive response to storm events, as well as a monitoring of subsequent beach recovery in the short and medium term (<1 year). Results show how Storm Gloria (January 2020, Hs max = 7.62 m) acted as a disruptive event and shifting point in the shoreline trend. As a response to that storm, major erosive processes occurred along the delta that caused an average shoreline retreat of 47 m. A progressive recovery during the spring and summer was mainly associated with periods of low wave energy. Nevertheless, by the end of the year a complete recovery had been achieved for about half of the coast, while the other half showed an average erosion of more than 10 m when compared to the pre-storm situation. Both the erosive and the recovery processes took place unevenly on different sections of the coast, probably dependent on factors such as the orientation of the beach and the pattern of longitudinal sediment transport along the coast. • Automatic shoreline extraction from Sentinel 2 and Landsat 8 imagery using SAET. • Pre and post-storm characterisation of SDS position in time and space using STMs. • Storm Gloria (January 2020) caused an unprecedented and heterogeneous impact on the Ebro Delta. • Slow recovery occurred in the months following the event conditioned by orientation and wave patterns. • About half of the delta showed a significant shoreline retreat by the end of 2020. [ABSTRACT FROM AUTHOR]

The formation of the Jiangsu radial sand ridges (RSRs) in East China has received extensive attention. However, the provenance of the Jiangsu RSRs sediments is still controversial. In this study, the Pb isotopic compositions of residual fractions were used to elucidate the provenance of the Jiangsu RSRs sediments. The results showed that Pb isotopic compositions of sediments in onshore RSRs were not significantly different with those of the landward offshore RSRs, indicating the shoreward transport of sediments from the landward offshore RSRs. The combination of Pb–Nd isotopic compositions revealed that the seaward offshore sediments mainly originated from the Yangtze River Mouth, while the onshore and landward offshore sediments were dominantly supplied by the Old Yellow River Delta through the southward flow. This study provides a deep insight into the evolution of Jiangsu RSRs, and is of great value to the Jiangsu coastal protection. • Pb isotopic compositions were only associated with source rocks. • Shoreward transport of sediments from the landward offshore RSRs. • Seaward offshore sediments mainly originated from the Yangtze River Mouth. • Onshore sediments were dominantly supplied by the Old Yellow River Delta. [ABSTRACT FROM AUTHOR]

Coastal zones are dynamic environments where sediment transport significantly influences erosion, deposition, and ecosystem stability. Accurate modelling of the complex interactions between hydrodynamics, sediment transport, and morphological changes in high-energy shoreface areas is crucial for sustainable coastal management. This study aims to assess sediment dynamics and understand the dominant physical drivers of sediment transport in the shoreface by coupling high-resolution numerical modelling with a shoreface sand tracer experiment. Results from the field experiment showed high diffusion and a net onshore and downdrift movement of the tracer in agreement with the observed hydrodynamic data. The numerical modelling strategy, validated with in situ hydrodynamic data and tracer results, demonstrated good performance and highlighted the dominant modes of shoreface sediment transport. While during low energetic wave conditions, the dominant transport mechanism involves the slow-rate bed load sediment movement toward the shore, under moderate energetic wave conditions, longshore wave-induced suspended transport becomes the prevailing mode of transport. The study provides valuable insights to increase the understanding of sediment transport in the shoreface and highlights the importance of coupling numerical modelling with sediment tracer experiments. • Field observations and numerical modelling are used to understand sediment transport in the shoreface • Conceptual sediment dynamic model combines Lagrangian and Eulerian approaches • Energetic wave conditions increase wave-induced currents and sediment transport rates, with waves breaking over the bar crest. • Streaming and wave nonlinearities are the main drivers of sediment transport in the shoreface • Alongshore suspended transport dominates in the surf zone, distributing sediments downdrift [ABSTRACT FROM AUTHOR]

Sediment motion on rippled bed under wave action plays an important role in coastal landforms, but the application of traditional numerical model is limited by large computational work or bottom sediment condition due to unsteady effects. A single-phase model is proposed to maintain low computation and high accuracy for the vortex structure development and suspended sediment motion on vortex rippled bed in wave-induced oscillatory flow. The 2D bottom sediment condition takes into account the acceleration effect and asymmetric boundary layer development under nonlinear waves as well as the sediment phase-lag. The particle inertia and wake flow around sediment particle are considered in sediment turbulence, and the SST k - ω turbulence model which is suitable for inverse pressure gradient flow on rippled bed is selected to close the Reynolds stress. The single-phase model well predicts the velocity on vortex ripples, periodic concentration at fixed points and vertical distribution of averaged sediment concentration. The results show qualitative formation, development and ejection of vortex, and demonstrate quantitative development of vortex center, radius and strength in symmetric and asymmetric flows. In addition, the model well performs the development of sediment cloud referring to vortex structure. • Efficient numerical model is developed for oscillatory sediment transport on vortex ripple and sheet flow. • Bottom sediment condition performs acceleration effect, asymmetric boundary layer and phase-lag. • Particle inertia and wake flow around particle are considered in sediment turbulence. • SST k - ω turbulence model is applied for inverse pressure gradient flow on vortex ripple. • Results show quantitative development of vortex structure and associated sediment cloud. [ABSTRACT FROM AUTHOR]