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AlMashan, N.; Al-Attar, I., and Neelamani, S., 2024. Assessment of annual sedimentation into Failaka Marina (Kuwait) and possible solutions for reduction of siltation. Journal of Coastal Research, 40(3), 527–553. Charlotte (North Carolina), ISSN 0749-0208. Sedimentation is critical for ports, harbors, and marinas, requiring accurate assessment. Failaka Marina in Kuwait is experiencing a severe noncohesive sedimentation problem. The samples collected at the seven locations along the beach showed that the beach has a uniform grain-size diameter, meaning it is poorly graded sand. The sampling at the tip of the southern breakwater showed that the shoaling is mainly sand. The suspended-sediment concentration varies from 0.025 kg m–3 to 1.2 kg m–3, whereas the mean concentration at the marina entrance is 0.85 kg m–3. The time series of the suspended solids over a year in the seawater surrounding Failaka Island shows a range of 8 to 48,069 ppm. Such a considerable variation in suspended load is due to the massive amounts of dredging and spoil disposal at Boubyan Island and Basra Port (Iraq) when a high sediment load moves around Failaka Island with a concentration of more than 40,000 mg L–1. Annual sedimentation is about 2.35 m y–1, which is responsible for blocking the main entrance for navigation. Kuwait's Ministry of Communication allocates $4 to $6 million annually for dredging and disposal activities. This study evaluates the six marina entrance modification scenarios to determine the best scenario that achieves a measurable reduction in sedimentation rate in the Marina. Six marina breakwater modifications were studied, and annual sedimentation rates were numerically computed. The study use Coupled MIKE 21/3 to simulate hydrodynamic conditions for cohesive sediment transport in a problem area. Field data from 2015 calibrated and validated the model. The primary sediment-moving force is SE wind and sea-swell waves. Littoral drift along Failaka Island's southern coastline and high suspended-sediment concentration result in littoral drift and settling. The best scenario showed a 28% sedimentation reduction and a 26% reduction in maintenance dredging costs from the six studied scenarios. [ABSTRACT FROM AUTHOR]

Grain size affects the rates of aeolian sediment transport on beaches. Sediment in coastal environments typically consists of multiple grain‐size fractions and exhibits spatiotemporal variations. Still, conceptual and numerical aeolian transport models are simplified and often only include a single fraction that is constant over the model domain. It is unclear to what extent this simplification is valid and if the inclusion of multi‐fraction transport and spatial grain‐size variations affects aeolian sediment transport simulations and predictions of coastal dune development. This study applies the numerical aeolian sediment transport model AeoLiS to compare single‐fraction to multi‐fraction approaches for a range of grain‐size distributions and spatial grain‐size scenarios. The results show that on timescales of days to years, single‐fraction simulations with the median grain size, D50, often give similar results to multi‐fraction simulations, provided the wind is able to mobilize all fractions within that time frame. On these timescales, vertical variability in grain size has a limited effect on total transport rates, but it does influence the simulation results on minute timescales. Horizontal grain‐size variability influences both the total transport rates and the downwind bed grain‐size composition. The results provide new insights into the influence of beach sediment composition and spatial variability on total transport rates toward the dunes. The findings of this study can guide the implementation of grain‐size variability in numerical aeolian sediment transport models. Plain Language Summary: The growth of coastal dunes is caused by the wind, which moves sand from the beach to the dunes. The sand grains on the beach have different sizes. For instance, the size of the sand grains can vary from the waterline to the start of the dunes. Small sand grains are more easily picked up by the wind than larger, heavier grains. Thus, the size of sand grains and how they are spread over the beach can impact how much sand is moved by the wind. We use computer simulations to calculate how much sand is moved by the wind under different conditions. We investigate how different assumptions about the grain size on the beach influence these calculations. The results show that the calculations with one single sand size, in most cases, give comparable results to simulations with more complicated sand size variations. The simplified approach is beneficial because it reduces the need for detailed field data of grain sizes for future calculations. Key Points: The effects of multi‐fraction transport and spatial grain‐size variations were examined with the numerical aeolian transport model AeoLiSThe D50 can be used as a representative grain size in aeolian sediment transport modeling on a time scale of days to yearsThe bed surface grain size in the upwind source area might be the most relevant to include in aeolian sediment transport models [ABSTRACT FROM AUTHOR]

The advances in morphodynamics numerical modelling and the free availability of such updated models have made XBeach a powerful tool to predict the hydrodynamic and morphologic processes on sandy coasts. This paper addresses the impact of the sea-structure-sediments interactions in the morphological evolution of a coastal stretch which undergoes erosion and overtopping despite having a combined groyne field-dune-seawall defence scheme. Preliminary tests, tailored to conclude on the model mode-version to be applied in the case study, evidence the importance of considering the NH mode. After calibrated and validated, the model was applied for a set of cases to compute and discuss the effect of the individual defence scheme structural elements and the hydrodynamic driving factors, namely the wave energy and obliquity and the tidal range, on the morphodynamics. The results revealed that the seawall aggravates the erosion of the beach, despite being essential in the protection against overtopping and coastline retreat, and that the present configuration of the groyne field does not provide enough protection at the downdrift part of the stretch. The knowledge acquired can support the interpretation of the topo-bathymetric behaviour in similar coastal defence schemes existent worldwide. [ABSTRACT FROM AUTHOR]

In sandy beach systems, the aeolian sediment transport can be governed by the vertical structure of the sediment layers at the bed surface. Here, data collected with a newly developed sand scraper is presented to determine high‐resolution vertical grain size variability and how it is affected by marine and aeolian processes. Sediment samples at up to 2 mm vertical resolution down to 50 mm depth were collected at three beaches: Waldport (Oregon, USA), Noordwijk (the Netherlands) and Duck (North Carolina, USA). The results revealed that the grain size in individual layers can differ considerably from the median grain size of the total sample. The most distinct temporal variability occurred due to marine processes that resulted in significant morphological changes in the intertidal zone. The marine processes during high water resulted both in fining and coarsening of the surface sediment. Especially near the upper limit of wave runup, the formation of a veneer of coarse sediment was observed. Although the expected coarsening of the near‐surface grain size during aeolian transport events was observed at times, the opposite trend also occurred. The latter could be explained by the formation and propagation of aeolian bedforms within the intertidal zone locally resulting in sediment fining at the bed surface. The presented data lays the basis for future sediment sampling strategies and sediment transport models that investigate the feedbacks between marine and aeolian transport, and the vertical variability of the grain size distribution. [ABSTRACT FROM AUTHOR]

Effective coastal management requires an understanding of sediment dynamics. This study examines the distribution of heavy minerals (HMs) in two distinct coastal regions: the mainland and spit, each with unique sediment deposition patterns. The spit accumulates sediment through alongshore sediment transport (AST), while the mainland experiences erosive processes and significant human impacts. The hydrodynamic behaviour and weathering resistance of HMs enables source identification. This has helped to reveal differences between the two regions, with apatite being characteristic of spit sediments and garnet of mainland beaches. Coastal processes, such as erosion, sediment transport, and accumulation, significantly shape the distribution of the HMs, with garnets dominating erosive shores and amphiboles dominating accumulative shores. Furthermore, the study found that human-made coastal infrastructure also affects the composition of HMs and the sediment distribution through AST. This research has implications beyond the local level, providing global insights into the complexities of coastal dynamics. The study emphasises the importance of using HM analysis in conjunction with grain size analysis to understand the distribution of beach sediment composition. It also highlights the significant role of coastal processes, including anthropogenic impacts such as jetty construction or deepening port entrance canals on AST. • Heavy mineral analysis complements grain size analysis to study coastal sediment dynamics. • Heavy mineral composition in beach sediments aided in excluding three coastal areas along the studied sea coast. • Heavy mineral distribution patterns revealed disruptions in alongshore sediment transport due to coastal infrastructure. • Heavy mineral composition depends on coastal processes: garnets dominate on eroding, and amphiboles on accumulative shores. [ABSTRACT FROM AUTHOR]

Featured Application: Geochemical analysis can provide valuable information about the local and regional patterns of sediment transport, distribution, provenance, and coasts' conditions. Sandy coasts are one of the most dynamic spheres; continuously changing due to natural processes (severe weather and rising water levels) and human activities (coastal protection or port construction). Coastal geodynamic processes lead to beach sediment erosion or accumulation. The coast's dynamic tendencies determine the changes in the volume of beach sediments; grain size; mineralogical; and geochemical composition of sediments. In addition to lithological and mineralogical analysis of sediments, geochemical analysis can provide valuable information about the local and regional patterns of sediment transport, distribution, provenance, and coasts' conditions. The study aims to assess trace metals' temporal and spatial distribution determined in the sandy beach sediments along the south-eastern Baltic Sea coast (Lithuania) during 2011–2018. The Lithuanian seacoast is divided into two parts: mainland and spit coast. Our results revealed that the dominant group of elements on the mainland includes Ca–Mg–Mn–Ti and on the Curonian Spit Fe–Pb–As–Co–Cr–Ni–Al, which remain unchanged during the years. The analysis included additional parameters such as beach volume, grain size and sorting, and heavy mineral concentration on the beach. The spatial analysis of trace elements indicated that the trace metal content depends on the coastal processes, but it differs in the mainland and spit sea coast. We identified a higher concentration of trace metals in the erosion-dominated areas in all analysed years on the mainland coast. On the spit coast, the trace metal concentration increased in areas associated with relict coarse sand and where the loading of sediments was active on the beach due to the northward along-shore transport. [ABSTRACT FROM AUTHOR]

The direct impacts of storms on beaches have been well studied; less well understood are the controls of storms on their seasonal‐interannual evolution. We apply a novel empirical orthogonal function (EOF) analysis to a 5‐year data set of monthly subaerial beach topography at Kennedy Space Center, Florida, to extract dominant spatiotemporal topographic patterns. Our hybrid surface EOF (SEOF) approach applies 1‐D EOF techniques to a data set varying in two dimensions, thereby extracting topographic patterns in the longshore and cross‐shore simultaneously while preserving the analytical simplicity of 1‐D approaches. These topographic patterns are then linked to observations of storm impacts. Our approach comprehensively illustrates that storms influenced local topographic evolution over event‐to‐interannual‐timescales. The first mode of topographic variability captures an interannual‐scale change in behavior triggered by the impact of Hurricane Sandy (2012), whereby a cape feature began and sustained rapid aggradation following the event. This pattern is likely linked to storm‐response processes and pre‐existing morphodynamic feedbacks, illustrating that storm response can dictate poststorm recovery processes. This pattern overwhelmed a spatially uniform, seasonal topographic signal, which we attribute to seasonal variability in water level and storminess forcings. The third mode shows links to local framework geology and suggests that some storms can create and/or destroy subaerial berms at this site, where spatial variability of berm existence in discrete longshore compartments can remain stable until a future event. Our results illustrate mechanisms by which storms can create persistent topographic imprints that remain visible for months‐years following events, potentially influencing response to future storms. Key Points: A surface empirical orthogonal function analysis comprehensively reveals spatiotemporal patterns in coastal topographyStorm‐influenced local topographic patterns include interannual‐scale behavior change, a seasonal signal, and a berm existence cycleStorms can have impacts that remain imprinted in the topography for months‐years afterward, likely affecting response to future events [ABSTRACT FROM AUTHOR]

The abundance of fecal-indicating bacteria in water bodies are said to be influenced by environmental conditions. The effect of environmental parameters on the changing microbial population plays an important role in coastal water quality assessment. It's crucial to comprehend these patterns in order to support management initiatives for pollution control. There are studies on faecal bacteria contamination of surface water and how environmental conditions affect it, however majority of them are based on large river basins and temperate regions of developed countries. In this paper, we study the different physicochemical and physical factors of the five recreational beaches in Mumbai, India and examine how these environmental factors affect the levels of faecal indicating bacteria, namely, coliforms in the region. A relatively high number of coliform was identified from the water and sediment samples of Marve Beach (>1600 MP N/100 ml or g), followed by Erangal Beach and Danapani Beach (∼150–350 MP N/100 ml or g), exceeding the normal standard limits of <100 MP N/100 ml set by the Central Pollution Control Board (CPCB) of India. Of the physiochemical parameters examined, BOD showed to have a strong positive correlation with the coliform bacteria. The nutrients and heavy metal concentrations did not show any major effect on the microbial population. The MIKE CMAP predicted tide, MIKE3 Flow Model FM simulated coastal current, ERA5 hourly wind, as well as SWAN model simulated nearshore wave together considerably exhibit alliance of microbial behavior in the beaches with ambient physical processes. This study reveals that Mumbai's coastal water contain significant concentrations of faecal bacteria, which, if not monitored regularly could have future consequences on the recreational activities of the region, thereby on public health. This assessment might help in simulation of water quality prediction, and for optimizing the coastal zone management and development across recreational beaches. [Display omitted] • Current, wind pattern and location are important in the faecal pollution studies. • High fecal indicating bacteria was seen in Marve Beach (>1600 MP N/100 ml or g). • BOD had a strong positive correlation with the coliform bacteria. • Nutrients and heavy metal concentration did not show effect on the study. [ABSTRACT FROM AUTHOR]

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Muthusankar, G.; Proisy, C.; Balasubramanian, D.; Bautès, N.; Bhalla, R S.; Mathevet, R.; Ricout, A.; Senthil Babu, D., and Vasudevan, S., 2018. When socio-economic plans exacerbate vulnerability to physical coastal processes on the south east coast of India. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 1446–1450. Coconut Creek (Florida), ISSN 0749-0208. Industrial and urban development along the coast may exacerbate the changes induced by oceano-climatic processes to such an extent that the coast becomes uninhabitable. This paper presents a baseline study carried out on the 360 km-long Coromandel coast of Tamil Nadu's (TN) Bay of Bengal coast, Southeast India. About 30% of the 72 million inhabitants of the state of TN live in low-lying coastal areas within a variety of ecosystems such as sandy beaches and dunes, wetlands, mudflats and mangroves. Exponential demographic growth combines with dense urban agglomerations, ever-growing industrial and harbour areas, aquaculture and luxury tourism expansion increasing vulnerabilities to coastal erosion and extreme meteorological events. We report here how very high spatial resolution satellite (VHSRS) images, freely provided by Google Earth® engine or from the public database offered by GIS software, may be used to impartially and significantly survey coastal land cover (LC) transformations at fine scales over a number of years using preliminary visual interpretation. The study also gathered demographic data, historical records on strength and trajectories of the cyclones that have hit the TN coast since 1900, and decadal series of daily ERA-Interim/ECMWF waves and Mercator-Ocean oceanic currents. Our results demonstrate a tangle of environmental and human activities and situations subject to specific coastal hazards, particularly severe during the Northeast monsoon season. The potential risks for coastal ecosystems and local communities are finally discussed. [ABSTRACT FROM AUTHOR]

Wave climate and Pacific basin coastal behaviour associated with El Niño Southern Oscillation (ENSO) is understood at a reconnaissance level, but the coastal response to different central Pacific (CP) versus eastern Pacific (EP) flavours of ENSO is unknown. We show that CP ENSO events produce different patterns of directional wave power to EP ENSO along the southeast Australian shelf and southwest Pacific region, because of significant variability in trade-wind wave generation. The modulation of the trade wind wave climate during CP ENSO has thus far been neglected in existing coastal process studies. We also show that coastal change between CP and EP ENSO cannot be inferred from shifts in the deepwater wave climate. This is because variability in trade wind wave generation is masked in deepwater by the persistence of high power extra-tropical waves that have reduced impact on nearshore processes due to high wave refraction. Morphodynamic modelling in a headland-bay beach indicates that CP ENSO leads to higher coastal erosion potential and slower post-storm recovery than EP ENSO during an El Niño/La Niña cycle. We show that the alongshore variability in beach morphological type can be used to model the static equilibrium planform response for each ENSO phase. Results indicate that shoreline response to ENSO in most headland-bay beach coasts is not as simple as the existing paradigm that (anti-) clockwise rotation occurs during El Niño (La Niña). Our methods provide a second-order approach to project coastal response and predict the discrete shoreline rotations for ENSO flavours. [ABSTRACT FROM AUTHOR]

Harley, M.D.; Turner, I.L.; Splinter, K.D.; Phillips, M.S., and Simmons, J.A., 2016. Beach response to Australian East Coast Lows: a comparison between the 2007 and 2015 events, Narrabeen-Collaroy Beach. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 388-392. Coconut Creek (Florida), ISSN 0749-0208. East Coast Lows (ECLs) are intense extratropical cyclones that form off the east Australian coastline and are known to cause significant beach erosion. This study presents analysis of the beach response to two severe ECLs that occurred in the Sydney region in June 2007 and April 2015 based on a three-dimensional coastal monitoring program undertaken at Narrabeen-Collaroy Beach. The results indicate considerable reductions in the subaerial sand volume for both storms, with an average (maximum) reduction of 78 m3 (124 m3) per alongshore meter for the 2007 event and 58 m3 (104 m3) per alongshore meter for the 2015 event. The overwhelming majority (93%) of subaerial beach erosion for both storms was observed to be within the berm section of the beach profile. Further analysis into the alongshore variability of cross-shore beach response reveals that the enhanced erosion during the 2007 event was mainly concentrated in the mid to northern sections of the embayment. It was found that this enhanced erosion was predominantly a result of a greater berm volume in this section of the embayment prior to storm arrival and that berm response to these two events was very similar (R2 = 0.81) when considering erosion as a percentage of the pre-storm berm volume. It is concluded that the berm reduction as a percentage of the pre-storm berm volume can potentially provide a suitable predictor for the beach response to severe ECLs within littoral cells along this coastline. [ABSTRACT FROM AUTHOR]

Ruiz de Alegria-Arzaburu, A.; Arreola-Cortez, M.A.; García-Nava, H.; Hernández-Walls, R., and Mejía-Trejo, A., 2016. The effects of beach morphology variations on the profile of nearshore currents on a gently sloping mesotidal beach. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 457-461. Coconut Creek (Florida), ISSN 0749-0208. Concurrent measurements of subtidal beach morphology and profiles of nearshore currents have been collected over a year period on a gently sloping mesotidal beach in the northwestern coast of the Baja California peninsula in Mexico. Data collected in August 2014 and February 2015 during similar tide, wave and wind conditions are compared at different alongshore locations on the beach in order to determine differences on the vertical structure of the nearshore currents in relation to significant morphologic variations. The beach presents a clear seasonal variability, showing the formation of an inner sandbar during the winter as a result of the erosion of a large portion of the subaerial beach. The morphological differences on the inner subtidal beach shows a subsequent effect on the vertical structure of the nearshore currents. Locations with pronounced sandbars have generally associated cross-shore and longshore components of the current of larger magnitude. Generally, the surface and bottom cross-shore currents are the most energetic while the middle layer presents milder magnitudes. With the presence of an inner bar, the shoreward directed upper and bottom layers become wider (deeper) reducing the width of the middle less energetic layer, and after the breaking zone the water column becomes vertically quasi-homogeneous. This study contributes to the understanding of the feedbacks between the hydrodynamic forcing and the beach morphology. [ABSTRACT FROM AUTHOR]

We analyse the response of small embayed sandy beaches in marginal seas to various hydrometeorological drivers to isolate a specific mechanism that may stabilise beaches under bi-directional wind patterns. The focus is on the evolution of two sandy beaches (Pirita and Russalka) in Tallinn Bay, northeastern Baltic Sea, that are about 3 km apart and oriented at an angle of 35° with respect to each other. A large proportion of annual wave energy flux is packed into a very few days in the year. The wind direction, and thereby the direction of the wave fields, of the strongest storms in the year determines which coastal areas are most affected. We quantify the response of the beaches to hydrometeorological conditions over 12 years, 2008–2020 based on annual high-resolution measurements using airborne and terrestrial laser scanning technology. The fastest sediment removal from the subaerial beach occurs during time periods with elevated water level and strong wave energy flux. Even though annual variations in the sand volume of the subaerial beach are significant, both beaches are stable during the decade studied but respond differently. We outline specific mechanisms that maintain the beaches, best illustrated at Pirita beach where there is strong longshore sediment transport component driven by waves that often arrive the beach at a large angle. Sand that is removed from the higher subaerial segments of the northern part of Pirita beach and moved to the south by north-west storms during periods of elevated water levels, is deposited in the shallow nearshore (above about −0.5 m of the mean sea level). This sediment is then able to be transported back to the north during periods of lower water levels where even relatively small waves generated by moderate south-westerly winds can entrain and move the sediment. This mechanism, different from the classic cut and fill cycle, may implicitly stabilise beaches where there is a bi-directional wind regime and a small tidal range. Another, less explicit cross-shore mechanism, is found for the differently oriented Russalka beach where waves usually approach at a small angle with respect to the shore normal. This beach is maintained by a synchronisation of intense waves and water level that limits the depth of deposited sand with respect to mean sea level. The two mechanisms are thus fairly similar, however Pirita beach has extensive alongshore excursions of sand. • Laser scanning technique applied to quantify, in detail, the evolution of two beaches over 12 years. • The patterns of change generally do not match the course of hydrometeorological drivers. • The beaches are stabilised by specific mechanisms. • Sediment is moved in one direction under elevated water levels and back under low water levels. [ABSTRACT FROM AUTHOR]

We address the possibilities of combining terrestrial (TLS) and airborne laser scanning (ALS) techniques with the classical concept of equilibrium beach profile to quantify the changes in the total sand volume of slowly evolving sandy beaches. The changes in the subaerial beach are determined from a succession of ALS surveys that were reduced to the same absolute height using a TLS survey of a large horizontal surface of constant elevation. The changes in the underwater sand volume from the waterline down to the closure depth are evaluated using an inverse of the Bruun Rule. The relocation of the waterline is extracted from the ALS scanning of elevation isolines of 0.4-0.7 m. The method is applied to an about 200 m long test area in the central part of Pirita Beach (Tallinn Bay, north-eastern Baltic Sea). The sand volume in this area exhibits extensive interannual variations. The annual gain of sand in the entire beach was about 2000 m³/y in 2008-2010 and the annual loss was about 1100 m³/y in 2010-2014. The changes in the underwater part of the beach are by a factor of 2-2.5 larger than the changes in the subaerial part. [ABSTRACT FROM AUTHOR]

An in-depth analysis has been made to simulate hydrodynamic scenarios for understanding the nearshore sediment transport controls of placer mineral depletion at Manavalakurichi, India. From the analyses of topographic configuration (extracted from Hydrographic Nautical Chart No. 2048 and data generated during year 2010), we inferred that the 5-m isobaths had broadened and exhibited shallowness. Distances between the coastline and the isobaths were found to have increased significantly over the past five decades. Along with this, the 10 and 20-m contours were found to have shifted about 35-100 m horizontally landward. These changes led to severe sediment deposition in these regions due to the changed wave energy levels and refraction patterns. Numerical simulations linking bathymetry, hydrodynamics, sediment load, and significant wave heights revealed that changes in bathymetry would amplify the wave heights and convergence of wave energy. Associated removal of sand from the high-energy zones will eventually lead to sediment starvation situations and depletion of placers in the adjacent beaches. As the observed trends of depletion generate great concern, detailed oceanographic investigations should be taken up immediately in the region. Fine-resolution hydrodynamic datasets should prove useful for further evaluating the physical responses of the system to the altered geometry and for exploring remedial measures for restoring the heavy mineral content of the beach sand. [ABSTRACT FROM AUTHOR]

Royal Hawaiian Beach in Waikīkī plays an essential role in Hawai'i's tourism-based economy. To inform development of management policies, we conduct two years of weekly ground and aerial surveys (April 2018 to February 2020) to track change on this chronically eroding beach. We use multiple linear regressions, Self-Organizing Maps (a form of cluster analysis), remotely sensed nearshore sand fields, hydrodynamic modelling, and monitoring of key physical processes to identify the principal drivers of beach change. Our results show 12 months of subaerial accretion (+2400 ± 59 m3) followed by 10 months of erosion (−3090 ± 51 m3) for a net loss of 690 ± 51 m3, and document that interannual variations in beach width and volume overprint seasonal patterns. Notably, a seasonal signal is recorded in the topographic structure of the beach. We test the relationship of beach volume and width to variations in wind, water level, wave energy flux generated from southern hemisphere swell, and wave energy flux from locally generated trade-wind waves. We identify three beach segments and three nearshore sand fields that form a sand-sharing, source-sink network, yet operate quasi-independently. Our analysis reveals that individual beach segments and their adjacent sand fields experience coherent (simultaneous) gains and losses of sand, suggesting that alongshore sediment exchange is dominant over cross-shore exchange. The main drivers of beach change are variations in water level and wave energy flux. Beach volume and width both vary with nearshore sand cover, indicating that free exchange with nearshore sources is intrinsic to beach variability. Our results suggest that rising sea level and extreme El Niño-Southern Oscillation events will contribute to Royal Hawaiian Beach destabilization, which may amplify erosional events and increase the cost of future beach maintenance. • Two years of weekly beach observations identify environmental drivers of change. • Seasonal beach change is overprinted by interannual processes of erosion/accretion. • Cluster analysis reveals that beach topography is organized by season. • Sediment exchange is dominated by alongshore, not cross-shore patterns. • Nearshore and intertidal sediments respond coherently to wave forcing. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we review and synthesize field measurements of suspended sediment transport on the shoreface of dissipative, intermediate and reflective beach states. The morphodynamic beach state continuum was originally established in the 1970s but at the time, only hydrodynamic processes and morphologies in these various states were described. Since the early 1980s when sensors capable of resolving suspended sediment concentration at intra-wave time scale became available, many studies have examined suspended sediment transport by waves and currents on the shoreface. The synthesis of this work shows that the two end states in the morphodynamic continuum, which are the dissipative and reflective states, exhibit relatively small rates of cross-shore sediment transport and weak gradients in that transport which both ensure that the nearshore morphology is relatively stable. The intervening intermediate beach states typically exhibit prominent bar topographies and in these states, strong morphodynamic feedbacks between hydrodynamic processes and morphology create locally large transport rates and sharp transport gradients which is the reason for the dynamic nature of these beach states. Transport processes driving sediment onshore and offshore within beach states are discussed as well as the transport processes responsible for state transitions. [Copyright &y& Elsevier]

ABSTRACT Knowledge of surface moisture on beaches is vital for aeolian process studies because moisture increases transport thresholds and limits mass flux. A number of beach surface moisture measurement techniques have been employed in the field, including sample extraction, commercial soil moisture sensors, and remote sensing techniques. Each method has significant limitations in the context of aeolian process studies. This study was designed to test infrared optic techniques for measuring beach surface moisture. A simple infrared sensor (narrow-band radiometer) was developed to measure beach surface moisture content. The accuracy and practical usability of the narrow-band radiometer were assessed in comparison to a commercial handheld spectroradiometer. Field calibrations conducted at Cape San Blas, Florida and Padre Island, Texas indicated that the narrow-band radiometer performed quite well. The R2 values exceeded 0·98 in each case, and the standard error averaged about 1% moisture content compared with gravimetric moisture contents determined from 1·5 mm deep surface scrapes. The performance of the two instruments was found to be comparable, with the narrow-band radiometer slightly outperforming the spectroradiometer. In practical applications, the narrow-band radiometer also has logistical advantages and is better suited to measure large numbers of points. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Depth of closure (DOC) is a commonly-used parameterization of the seaward limit in significant elevation change along a beach profile. Engineers, scientists, and resource managers use this parameter to make decisions and formulate designs for activities ranging from ecological restorations to beach nourishment and harbor construction. We present empirically measured DOC values from eight sites along the U.S. East Coast from Long Island NY to Georgia. The sites represent a spectrum of settings between fully wave-dominant and mixed-energy barriers and beaches, and five of the eight surveys extend back at least one decade. There are multiple DOC formulations based on wave conditions that tend to over-estimate DOC values compared to empirical observations. Our results show a similar pattern, with modeled DOC averaging 2.5 m (m) deeper than surveyed values but yielding reasonable results in wave-dominant environments. Along mixed-energy sites, modeled DOC values range from 1.0 to 5.7 m deeper than empirical observations. Alongshore comparison of observed DOC values within individual sites also suggests the movement of shoals on the lower shoreface near inlets may further complicate DOC estimates compared to strand-type shorelines with relatively featureless nearshore slopes. • Empirical estimates of Depth of Closure vary along the US East Coast with tide range. • Modeled values of Depth of Closure are closer to the empirical observations under wave-dominant conditions. • Tidal inlet shoals and bars may represent a confounding factor in determining Depth of Closure. [ABSTRACT FROM AUTHOR]

The basic factors affecting sediment supply for and transport processes at Pirita Beach, a sandy section of the southeastern coast of Tallinn Bay, are analysed. Observations of bathymetry, sediment properties and sources, sediment transport processes and their changes arising from coastal engineering activities are reported. The mean grain size is about 0.12 mm, with the fine sand fraction (0.063-0.125 mm) accounting for about 77% of the sediments. Coarse sand dominates only along the waterline. The content of coarser sediments is greater in the northern part of the beach. A number of coastal engineering structures have blocked natural sediment supplies. The beach suffers from sediment deficit now and has lost about 400 m³ of sand annually from the dry beach between 1997 and 2005. [ABSTRACT FROM AUTHOR]

Analytical solutions to a beach evolution equation are obtained for the case where the initial beach shape may be an arbitrary function of position and where the forcing conditions may be a (known) function of time. The focus of this paper is the derivation of a generalized solution to the one-line equation describing the impact that time varying forcing can have on beach development close to a groyne. Explicit solutions are obtained using an integral transform technique. The solutions are found in terms of closed-form integrals which, for all but the simplest cases, require numerical evaluation. Example applications of the new solutions are described. [ABSTRACT FROM AUTHOR]

This study analyzed the seasonal variation of sedimentary reservoirs in sandy beaches located at the insular margin of a tidal inlet (Itamaracá Island, Pernambuco, Brazil). We measured the sedimentary budget and identified the dominant coastal processes (accretion or erosion) from Dec/2017 to Dec/2018. In six field campaigns by a Remotely Piloted Aircraft System, digital terrain models and extracted cross shore profiles were obtained which allowed for the quantification of beach morphology variability by variations in sedimentary volume. The following three sectors were classified and analyzed according to their location and coastal alignment in relation to the tidal inlet: internal (O–L), intermediate (SW–NE), and external (S N) sectors. ERA Interim reanalysis data were used to evaluate the regional standards of ocean surface waves and wind, showing predominance of southeast (109° and 124°, respectively) and wave power with average peaks of 46.5–51.8 kW/m (dry season) and 57–65.3 kW/m (rainy season). Sedimentary gain took place between Apr–Jul/2018, with Sep–Dec/2018 being the period of greatest loss. The internal sector showed positive sedimentary budget (+704.52 m3) with the prevalence of the accretion process, while both intermediate and external sectors lost about 5009 and 14,110 m3, respectively, with the erosive process prevailing at the end of the studied period. • A Dominant erosive process acting on the Itamaracá Island southeastern sandy beaches • During the rainy season higher speeds are expected from the ebb and flood tide currents. • Higher values were observed in the tide average amplitude and wave power during the rainy season. • RPAS and GNSS combination is adequate for understanding morphological and sedimentary evolution. • RPAS based photogrammetry allows for the generation of orthophotomosaics and DTMs in a practical and economical way. [ABSTRACT FROM AUTHOR]

Since 2011, beach nourishment has become the preferred solution for mitigating coastal erosion along the Mediterranean coast of Israel, as it is considered "soft" and environmentally friendly. However, using fine sand for nourishment in Israel without supporting measures is problematic due to the high wave energy and strong longshore currents in the littoral zone that tend to drift the sand away. This would require ongoing, multiyear, costly, and never-ending maintenance. In the present study, we analyzed sand and pebble alternatives for nourishment of the eroded beach in front of Tel Ashkelon, an important coastal archaeological site in southern Israel that suffers from severe erosion. Based on Pranzini et al. (2018), we analyzed the alternatives, evaluated their cost and efficiency, and assessed their potential environmental impacts. The study concluded that for protecting the southern part of Tel Ashkelon beach, pebble nourishment is the optimal solution, mainly regarding durability and cost. Using this material for nourishment will better absorb the storm wave impact and protect the foot of the archaeological Tel from erosion, and require lower maintenance cost than using finer sand nourishment. [ABSTRACT FROM AUTHOR]

Biausque, M. and Senechal, N., 2020. Analysis of two contrasting seasonal recovery periods of an open sandy beach, using high frequency DGPS surveys. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 377-381. Coconut Creek (Florida), ISSN 0749-0208. High frequency DGPS surveys were undertaken for 2.5 years (November 2015 until April 2018) on an open sandy double barred beach in the SW of France (Biscarrosse Beach) covering three winter and two summer periods. On those latitudes, summers are usually described as seasonal recovery periods. The morphological response of the beach during two consecutive summer periods (2016 and 2017) has been analyzed to identify processes involved in seasonal recovery. Analysis of alongshore mean profiles indicates that the summer 2016 is marked by a progressive berm reconstruction, manly driven by cross-shore sediment transport. The beach recovery in 2016 can be characterized as complete with a stable berm through the summer season associated with steady beach cusps, and a seaward dune foot migration. During this summer the variations in volume of each section of the beach (intertidal/supratidal beach and dune) show sediment transport firstly orientated from the intertidal beach toward the supratidal one, and, later, driven from the supratidal beach to the dune. This cycle is coherent with recent observations described by Philips (2017). In contrast, the summer 2017 is characterized by an incomplete recovery, an unstable berm and so, a much more complex dynamic: the berm, rapidly rebuild (by the end of June), started to erode in July. Six sequences of cross-shore sediment exchanges are measurable along the season between the intertidal and the supratidal beach, inducing successive erosion/ accretion of both sections of the beach. Thus, according to those results summers 2016 and 2017 present variable spatial and temporal dynamics. Moreover, analysis of hydrodynamic and environmental factors indicate that recovery periods not only depend on hydrodynamic conditions, such as wave energy and tide, but also on winter/summer morphological coupling, and sandbar/beach coupling. [ABSTRACT FROM AUTHOR]

This study presents a vulnerability assessment methodology that was developed to analyze the Croatian Eastern Adriatic Coast (CEAC), which has extremely complex geomorphology. Local coastal retreat, slope instability phenomena, and the influence of marine erosion play a significant role in coastal geohazards in the southeastern coastal area of the Krk Island (Kvarner area, northeastern channel part of the Adriatic Sea). Recent studies emphasize the need to develop an adequate methodology to monitor its evolution and define adequate risk management strategies. The vulnerability analysis was performed on the basis of the available data, taking into account local geological and oceanographic conditions. The coastal vulnerability analysis of the CEAC presents an adaptation of the existing methodology, emphasizing the significance of the geological factor, and providing novel elements of the parameter analysis (i.e., coastal slope, beach width, and significant wave height). This methodology was adapted and improved for the local rocky coast, but can be used on other complex rocky coasts worldwide. The calculated Coastal Vulnerability Index (CVI) around the Stara Baška settlement should be considered to have priority over the vulnerable areas in further monitoring and investigations. [ABSTRACT FROM AUTHOR]