Watson, P.J., 2016. Acceleration in U.S. mean sea level? A new insight using improved tools.

The detection of acceleration in mean sea level around the data-rich margins of the United States has been a keen endeavour of sea-level researchers following the seminal work of Bruce Douglas in 1992. Over the past decade, such investigations have taken on greater prominence given mean sea level remains a key proxy by which to measure a changing climate system. The physics-based climate projection models are forecasting that the current global average rate of mean sea-level rise (≈3 mm/y) might climb to rates in the range of 10–20 mm/y by 2100. Most research in this area has centred on reconciling current rates of rise with the significant accelerations required to meet the forecast projections of climate models. The analysis in this paper is based on a recently developed analytical package titled “msltrend,” specifically designed to enhance estimates of trend, real-time velocity and acceleration in the relative mean sea-level signal derived from long annual average ocean-water-level time series. Key findings are that at the 95% confidence level, no consistent or substantial evidence (yet) exists that recent rates of rise are higher or abnormal in the context of the historical records available for the United States, nor does any evidence exist that geocentric rates of rise are above the global average. It is likely that a further 20 years of data will identify whether recent increases east of Galveston and along the east coast are evidence of the onset of climate change induced acceleration.

Rangel-Buitrago, N.G.; Thomas, T.; Phillips, M.R.; Anfuso, G., and Williams, A.T., 2016. Wave climate, storminess, and northern hemisphere teleconnection patterns influences: The Outer Bristol Channel, South Wales, U.K.

This paper investigates potential climate-change impacts on the Outer Bristol Channel (Wales, U.K.) by analysing a 15-year wave-buoy dataset (1998–2013) to characterise wave climate and storms. The research showed that the increasing storminess experienced during the latter half of the 20th century did not, as expected, continue into the first decades of the 21st century; however, the wave climate showed clear cyclic variation in average monthly significant wave height (H_s), with low values occurring between May and August (H_s < 1.4 m, H_smax < 6 m) and a minimum in August (H_s = 1.3 m, H_smax = 5.2 m). Monthly mean wave power was 27.4 kwm⁻¹, with a maximum of 951 kwm⁻¹ during December. The 267 storm events were recorded during the assessment period. Storm-severity distribution presented a log-normal trend, with weak and moderate events making up 73% of the record (125 and 69 events, respectively); significant (18%), severe (4%), and extreme (6%) storms resulting in 73 events that are more destructive made up the remainder of the record. Fifty-five percent of the monthly averaged wave variations, wave power, and storminess indices are linked to several teleconnection patterns, the most relevant being the Arctic Oscillation, with 23.45%, the North Atlantic Oscillation, with 20.65%, and the East Atlantic with 10.9%. This kind of characterization is essential for design considerations to any proposed developments within the Bristol Channel that affect the coastal zone, e.g., the proposed design of the Swansea Bay Tidal Lagoon, which is capable of generating over 542,000 MWhyr⁻¹ of renewable energy.

van Gaalen, J.F.; Tebbens, S.F., and Barton, C.C., 2016. Longshore sediment transport directions and rates from northern Maine to Tampa Bay, Florida: Literature compilation and interpretation.

This paper examines site-specific and regional longshore sediment transport directions and rates along the U.S. seaward coast from the northern Maine border to the mouth of Tampa Bay, Florida. From previous studies, it is known that along the coast, there are nodal zones, i.e. locations of divergence or convergence in longshore current, as well as variations in current direction and sediment transport rate. Available published field-based studies of sediment transport directions and rates were compiled to create a map of the direction and rate of longshore transport. A detailed compilation of local and regional published studies is provided in tables and in a sequence of eight regional maps. Compiled studies of longshore transport reveal a dominant southward direction. On the regional scale, 12 nodal zones are identified. At the local scale, the number of nodal zones increases by approximately an order of magnitude. This work builds upon the Master's thesis of van Gaalen (2004).

Kruel, S., 2016. The impacts of sea-level rise on tidal flooding in Boston, Massachusetts.

In Boston, Massachusetts, chronic tidal flooding due to sea-level rise will occur in many developed parts of the city over the next several decades and beyond. This study examines the frequency and severity of tidal flooding due to increases in sea level of between 0.3 to 1.8 m (1.0 and 6.0 ft), as well as where flooding will generally occur. Local tide gauge data are compared to the National Weather Service's flood stage categories to determine how frequently they will be reached at high tide as sea level rises. GIS data are used to demonstrate where flooding is likely to occur, and U.S. Census data are used to identify assets that will be impacted. The study also depicts the relationships among the multiple datums currently used to measure water levels in Boston. Results of the analysis indicate that in the absence of any new flood barriers, the incidence of minor tidal flooding will increase to about 75 times per year within Boston Harbor with 0.3 m (1 ft) of sea-level rise. Nine-tenths of a meter (3 ft) of sea-level rise will result in about 30 occurrences of moderate flooding per year, and 1.2 m (4 ft) will bring that same frequency of major flooding incidents. Tidal flooding due to 1.8 m (6 ft) of sea-level rise will affect approximately 20% of the population and land, as well as housing, public facilities, transportation infrastructure, and hazardous waste sites. The study suggests that future conditions will require the development of nonemergency responses to flooding as well as a new approach to urban floodplain management.

Hoang, T.C.; O'Leary, M.J., and Fotedar, R.K., 2016. Remote-sensed mapping of Sargassum spp. distribution around Rottnest Island, Western Australia, using high-spatial resolution WorldView-2 satellite data.

Satellite remote sensing is one of the most efficient techniques for marine habitat studies in shallow coastal waters, especially in clear waters where field observations can be easily carried out. However, such in situ observations have certain limitations: they are time consuming, have a limited ability to capture spatial variability, and require an interdisciplinary approach between marine biologists and remote-sensing specialists. The main objective of this study was to survey and map Sargassum beds around Rottnest Island, Western Australia, through a combination of high spatial resolution WorldView-2 imagery, using a validated depth invariant index model for water-column correction, and in-field observations. The combination of field survey data and four classification methods resulted in highly accurate classification outcomes that showed the distribution patterns of Sargassum spp. around Rottnest Island during the austral spring season (October 2013). Overall, the minimum distance and Mahalanobis classifiers yielded the highest overall accuracy rates of 98.32% (kappa coefficient, κ = 0.96) and 98.30% (κ = 0.96), respectively. The K-means classification method gave the lowest accuracy percentage of 42.50% (κ = 0.22). Thus, the primary results of this study provide useful baseline information that is necessary for marine-conservation strategic planning and the sustainable utilization of brown macroalgae resources around the Western Australian coast.

Albrecht, F. and Shaffer, G., 2016. Regional sea-level change along the Chilean coast in the 21st century.

Regional sea-level change for Chile is considered until the end of the 21st century for the representative concentration pathway (RCP)4.5 and RCP8.5 scenarios. The main components that contribute to sea-level change are analyzed and summed to achieve a total estimate of sea-level change along the coast of Chile and in the Southeast Pacific. Included are the steric/dynamic component, the contribution from land ice loss, and the sea-level change due to the glacial isostatic adjustment. Regional fingerprints and global means are combined to estimate sea-level change in this area. For the steric/dynamic component two different estimates are considered. The results are compared with those found in the Intergovernmental Panel on Climate Change Fifth Assessment Report. The total mean sea-level rise along the coast lies between 34 cm and 52 cm for the RCP4.5 scenario and between 46 cm and 74 cm for the RCP8.5 scenario, depending on the location and the steric/dynamic component estimate considered. This component is the main contribution in each scenario. All estimates show a modest, relatively constant decrease in sea-level rise along the coast from north to south.

Weaver, R.J.; Johnson, J.E., and Ridler, M., 2016. Wind-driven circulation in a shallow microtidal estuary: The Indian River Lagoon.

Studying wind-driven fluctuations in the surface elevation along the Indian River Lagoon (IRL) allows researchers to better understand the best methods for managing sustainable water quality in a microtidal estuary. Water quality has a direct effect not only on the marine life, but also on tourism. This study improves the knowledge of circulation and surge in a shallow, microtidal estuary while enabling validation of numerical modeling efforts. Two submersible pressure sensors were deployed in the IRL for 7 months. Data collected from these gauges is analyzed in conjunction with data from permanent gauges at Haulover Canal and Sebastian Inlet, with an emphasis placed on the relationship between surface elevation and meteorological forcing. A time series analysis was employed to correlate periods of harmonic oscillations with wind events. Analysis focused on the direction of the wind with respect to the along-estuary and cross-estuary orientation of the lagoon. Results indicate that the water rises or falls uniformly in the cross-estuary direction and is transported to the south during Nor'easter events, piling up at the constriction south of Sebastian Inlet. Study results will be used to provide a better understanding of circulation in shallow-water estuaries, as well as improve numerical models to better predict wind-driven circulation in the IRL.

Gibeault, C.; Neumeier, U., and Bernatchez, P., 2016. Spatial and temporal sediment dynamics in a subarctic salt marsh (Gulf of St. Lawrence, Canada).

Sediment transport in the salt marsh and the lagoon of Penouille is driven by tidal currents, waves, wind, and ice rafting, which interact with topography and vegetation to control the spatial distribution of surface sediments. Multiple linear regressions of 203 samples of marsh surface sediments show that grain size gets finer and organic matter content increases with distance from the lagoon inlet, the sandy peninsula, the closest creek, and the lagoon. The vegetation parameters and surface microtopography have only a minor influence. Locally, grain size can get finer with elevation, while organic matter content increases. However, across the entire marsh, grain size exhibits the opposite trend with elevation, a consequence of aeolian transport and ice rafting. The 94 samples covering the lagoon show a trend of finer grain size with distance from the lagoon inlet and with sea grass cover. Penouille marsh has been relatively stable from 1975 to 2008: analysis of five georeferenced aerial photographs shows that only 3% of the marsh area was lost due to outer marsh edge retreat. Ten sediment cores collected in the marsh show a thickness of 0.14–0.72 m of marsh sediments overlying a sandy substrate. Radiocarbon dates suggest that marsh establishment occurred in the north side of the lagoon around 1000–1200 cal BP. Accretion rates based on radiocarbon dates are 0.4–1 mm/y for several centuries, whereas ¹³⁷Cs dating indicates rates of 1–3 mm/y since 1963, and accretion plates indicate 2.9 ± 0.9 mm/y between 2010 and 2012. Accretion rates since 1963 are similar to the relative sea-level rise (RSLR) of 1.5 mm/y at Penouille for the 1969–2014 period. However, the accelerated RSLR of 3.7 mm/y observed over the last 20 years and additional RSLR due to climate change may progressively drown the marsh if accretion rate does not substantially increase.

Santos, F.L.; Reis, M.T.; Fortes, C.J.E.M.; Lotufo, A.D.; Neves, D.R.C.B.; Poseiro, P., and Maciel, G.F., 2016. Performance of a fuzzy ARTMAP artificial neural network in characterizing the wave regime at the Port of Sines (Portugal).

Techniques based on artificial neural networks (ANNs) have been increasingly applied to predict emergency situations, such as extreme wave conditions, wave overtopping or flooding, and damage to maritime structures, in coastal and port areas. In this work, a fuzzy adaptive resonance theory with mapping (FAM) ANN was trained to predict the wave regime both inside and at the entrance to the Port of Sines, one of the major trade and economic gateways of the Iberian Peninsula, located on the Portuguese west coast. In situ measurements using pressure sensors, wave buoy data, and results from two numerical wave propagation models—simulating waves nearshore (SWAN) and diffraction refraction elliptic approximation mild slope (DREAMS)—were used to train and validate the ANN. The wave regime was calculated for different points outside and inside the port. In general, the FAM predictions outside the port showed a satisfactory fit to the wave parameters (significant wave height, peak wave period, and mean wave direction) from the numerical model SWAN. Inside the port, differences from the DREAMS model were greater, because the optimized FAM parameters were obtained only for outside the port and the FAM network showed some difficulties in accounting for the complex phenomena of wave refraction, diffraction, and reflection within the port. Consequently, it is of paramount importance to obtain the FAM results based on fully optimized parameters to use the FAM output in place of the numerical models of wave propagation. Nevertheless, this methodology proved capable of providing a fast and satisfactory response that is especially useful in the scope of risk management, particularly in wave forecasting and warning systems.

Webb, B.M. and Marr, C., 2016. Spatial variability of hydrodynamic timescales in a broad and shallow estuary: Mobile Bay, Alabama.

Residence, exposure, and flushing times are examples of hydrodynamic timescales that describe the physical mass transport within a water body. The response and spatial variability of these measures to tides and discharge were investigated through hydrodynamic model simulations of Mobile Bay, Alabama using a two-dimensional depth-integrated circulation model coupled with a Lagrangian particle tracking model. Hydrodynamic timescales were estimated and analyzed using the particle tracking results. Flushing of the estuary was found to transition from tidally enhanced to river dominated for Q > 1715 m³ s⁻¹. A simple power law regression was found to accurately represent the spatially averaged timescales (R² > 0.99) for tidal and river forcing. Spatially averaged timescales generally ranged from 4 to 130 days, with large deviations related to particle initial position, magnitude of river discharge, and local winds. The longest timescales were found in areas where adverse pressure gradients contributed to water retention as a result of separated flow and closed-cell circulation. Increasing river discharge enhanced the barotropic pressure gradient, which dominated the along- and across-estuary momentum balances in all but the minimum flow scenario where the across-estuary balance was geostrophic. Meteorological forcing was found to increase the spatial variance in hydrodynamic timescales by as much as 60% as compared with cases with discharge and tides only. The increased spatial variability was a result of inhibited flushing due to enhanced northerly flows along the shorelines and expanded regions of closed-cell circulation in the eastern portion of the estuary.

Watabe, Y. and Sassa, S., 2016. Sedimentation history of sandbars in flood-tidal delta evaluated by seismic method in Lake Tofutsu, Japan.

An extensive pattern of sandbars within a flood-tidal delta complex can be seen at the tidal inlet of Lake Tofutsu, one of the lagoons located along the Okhotsk Sea in Hokkaido, Japan. The primary aim of this study was to investigate the sequential sedimentation history of these sandbars. The shear-wave velocity structure, which is equivalent to the stiffness variation, of these sandbars was examined using a surface-wave method called the multichannel analysis of surface waves (MASW) to identify and describe the stratigraphy of the flood-tidal delta at the tidal inlet of Lake Tofutsu. The MASW results demonstrated that even though the sandbars appeared to comprise the same sandy material, the sediment under the sandbars had a very varied stratigraphy, comprising the river-borne muddy sediment derived from the upstream side of the lagoon and wave-induced marine sandy sediment derived from the coastal sand of the Okhotsk Sea. The second aim of this study was to verify the sedimentation history described on the basis of the MASW results through laboratory testing of sediment samples collected at characteristic points along the MASW array. The sampling method was modified to be applicable to low-cost sediment investigation at tidal flats and was conducted by human power without the aid of an engine. The collected samples were examined in the laboratory to obtain the depth profiles of grain-size distribution and carbon 14 dating. The results obtained from the sampling are consistent with the sequential sedimentation history evaluated by MASW.

Tan, C.; Huang, B.; Liu, F.; Yang, Q.; Jiang, C., and Zhang, S., 2016. Transformation of the three largest Chinese river deltas in response to the reduction of sediment discharges.

The Yellow, Yangtze, and Pearl rivers deliver more than 1.2 × 10¹² m³/a of freshwater and 13.6 × 10⁸ t/a of sediment into the western Pacific Ocean, playing important roles in the morphological evolution of the ocean in this region. From the 1950s to the 2000s, the total sediment loads of the three rivers decreased by 81.2%; this change has been primarily caused by human activities, such as dam construction and water–soil conservation projects. The sediment loads in the Yellow, Yangtze, and Pearl rivers decreased by 89.9%, 62.1% and 57.1%, respectively, from the 1950s to the 2000s. In response to the sediment supply decrease, the sediment regimes of the river channels in the lower reaches of the three rivers generally transitioned from deposition to erosion since the 1990s. The erosion of the channel has modulated the characteristics of the suspended sediment delivered to the estuary; for example, the erosion of the lower river channel increased the sediment flux and caused relatively coarser suspended sediments to be delivered to the estuary. As a consequence of the changes in the river basins, the evolutions of the three river deltas have transformed in the 2000s. The subaqueous deltas of the Yellow and Yangtze rivers changed from deposition to erosion. However, the Pearl River delta generally prograded seaward, and a portion of its subaqueous delta (e.g., the Modaomen River mouth) underwent erosion. In the coming decades, the sediment discharges into the seas from these three rivers are likely to decrease further because of intensifying human activities. Therefore, enhanced erosion in the three river deltas will continue when the river deltas remain unprotected. Our study demonstrates that human activities in the three river basins can influence the morphological changes of the estuaries, indicating that a river basin and its coastal zone are an integrated system.

Cao, H.; Chen, Y.; Tian, Y., and Feng, W., 2016. Field investigation into wave attenuation in the mangrove environment of the South China Sea coast.

Coastal mangroves form the land-sea interface and face an increasingly aggressive threat from ocean waves as a result of sea-level rise. This study investigates the buffering effect of mangroves on the coast of Leizhou Bay in the South China Sea under two different climates (normal windy weather and storm). By doing this, we aim to establish the exact wave damping rate due to the presence of mangroves and to study the wave and spectral characteristics of wave energy in the vegetated area. Wave gauges are mounted along a cross-shore transect to monitor the wave conditions during particular time periods. From the data analysis, we found that the recorded maximum significant wave height is 22.3 cm at the outermost station and remarkable wave damping was experienced within the mangrove troops of 100 meters. To evaluate the wave dissipation on the mudflat, an empirical expression is proposed on the basis of the field data. In this way, the net vegetation-induced wave dissipation is quantified separately. The spectral analysis of wave energy shows the modalities of frequency-dependent wave energy dissipation under different weather conditions. From the results, we conclude that the wave height was strictly subjected to the concurrent water depth even under the storm condition. The relative water depth (to the wave height) determined wave generation or dissipation on the mudflat. Despite the existence of dissipation by the mudflat, wave energy was majorly attenuated by the mangrove system. The wind growth of wave energy is of great significance when studying the spectral characteristics of wave energy during storm conditions.

Kong, J.; Pan, M.; Shen, C.; Hua, G., and Zhao, H., 2016. Analysis of the morphological changes and related sediment transport mechanisms of the Baisha Shoal in the Qiongzhou Strait, China.

The morphological changes and evolutionary mechanism of the Baisha Shoal in the Qiongzhou Strait were investigated using various methods, including bathymetric chart comparisons, geomodeling, hydrodynamic modeling, and hydrologic statistical analysis. Water depths were extracted from digitized charts to explore the evolution of the Baisha Shoal and to quantitatively estimate the changes in the shoal area within the 5-m isobath. The grain-size trend analysis (GSTA) model was introduced to explain the features of bed sediment distribution and to analyze the sources of the sediment. Tidal flow models and wave models were adopted to simulate the tidal flows and wave fields around the Baisha Shoal and to reveal the sediment transport dynamics. Further comparisons based on a Mann-Kendall trend analysis and remote-sensing image data from different years were used to discuss the reason for the recent evolution of the Baisha Shoal. The results show that the formation of the Baisha Shoal was caused by the combined effects of reciprocating flow in the eastern and western directions and waves from the NE direction. However, in recent years, the Baisha Shoal has demonstrated an unsteady geomorphological state and is transitioning from a deposition-dominated state to an erosion-dominated state. Erosion has become most significant since 2004, as reflected in the shoal area within the 5-m isobath, which is decreasing by 0.732 km²/y. The analysis demonstrated that a reduction in sediment load and increased sand mining are the two most significant factors that are progressively altering the shoal morphology. If these issues cannot be resolved, the strong dynamic surroundings will aggravate the erosion of the Baisha Shoal. This study on the Baisha Shoal highlights the necessity of combining different approaches to better understand coastal evolutionary features, dynamic mechanisms, and evolutionary causes, as well as to guide future coastal protection engineering design.

Renjith, K.R.; Joseph, M.M.; Ratheesh Kumar, C.S.; Manju, M.N., and Chandramohanakumar, N., 2016. Nutrient distribution and bioavailability in a tropical microtidal estuary, southwest India.

This study estimates the spatial and seasonal variations of phosphorus and nitrogen fractions in the surface sediments of Cochin Estuary to assess their bioavailability and the factors governing biogeochemical distribution. Seasonal variations of the dissolved nutrients suggest that phosphorous buffering activity is very high in the estuary, and there could be a nitrogen limitation in the absence of any external input. Iron-bound and calcium-bound inorganic fractions were the major forms of sedimentary phosphorus in the central estuary. Upstream regions were characterised by higher proportions of organic phosphorus, mainly as alkali-soluble fractions. Bioavailable fractions ranged from 2.61% to 90.43% of total phosphorus and show a significant increase during the lean pre-monsoon period. This increase, which was not attributed to total phosphorus, could play a major role in negating any possible phosphorus limitation. The bioavailable nitrogen fractions varied from 1.57% to 23.89% of total nitrogen and were much lower when compared with phosphorus. Despite the concomitant increase in the water column as well as sedimentary nitrogen during the post-monsoon season, the seasonal variation was not reflected in the sedimentary bioavailable nitrogen percentage, as the increase was confined only to urea, which was found at negligible levels during the other seasons. The study showed that physical characteristics of the substratum play a major role in the geochemical distribution of nutrients, along with organic matter diagenesis. Higher heterotrophic activities fuelled by the allochthonous input of organic matter resulted in relatively lower retention of nitrogen in the sediments of Cochin Estuary.

Antón, A.I.; de la Peña, J.M.; Almazán, J.L., and Lechuga, A., 2016. Appropriate locations for geotextile bag revetments: An analysis.

Social pressure exerted by urban development, the increase in erosion on many coastal stretches, and the rise in sea level due to climate change over the last few decades have led governments to increase investment in coastal protection. In turn, a reduction in costs and increases in ease of construction and rate of implementation have led to sand-filled geotextile elements, such as bags, tubes, and containers, becoming an alternative or supplement to traditional coastal defence materials, such as rubble mounds, concrete, and so on. Not all coastal zones are appropriate for sand-filled geotextile structures as coastal defences. This article analyses suitable zones for locating geotextile bag revetments to protect coasts from storm erosion and concludes that the least suitable zones are the surf zone (on an open coast and on a slightly protected coast) and deep water (on an open coast), except if a suitable reinforcement is carried out when the demand makes it necessary this build this kind of defence.

Hyatt, M.W.; Anderson, P.A., and O'Donnell, P.M., 2016. Behavioral release condition score of bull and bonnethead sharks as a coarse indicator of stress.

Capture and handling stress can induce acidosis and sometimes mortality in sharks. To approximate physiological condition after capture, fisheries researchers may use a behavioral health assessment at release. The goal of this study was to assess the efficacy of the behavioral release condition score (BRCS) in estimating the physiological stress response. The score was tested against changes in acid-base, blood gas, and metabolite analytes (pH, partial pressure of CO₂, and lactate) and factors known to influence those analytes (species, capture and handling time, and water temperature) among wild-caught bull (Carcharhinus leucas) and bonnethead (Sphyrna tiburo) sharks. After gill net capture, sharks were processed for tagging, morphometrics, and blood sampling. Blood was sampled immediately before release. At release, a BRCS was assigned as good, fair, poor, or moribund. BRCS was modeled as a response to changes in blood analytes and putative stressors using ordinal logistic regression (OLR). Effects of significant main factors were further explored graphically and in chi-square tests or (multivariate) analyses of variance (MANOVAs/ANOVAs). Linear discriminant analyses with cross-validation were used to assess the ability of those factors to discriminate among BRCS on a case-by-case basis. The OLR models suggest that BRCS responds in species-specific ways to all three blood analytes and putative stressors. However, the broad overlaps in ranges of these parameters among BRCS lend prediction of BRCS by either of these two sets of predictors to be challenging to utilize. Given the coarse relationship of BRCS to acid–base status in these species, further investigation of this and other behavioral assessment methods is recommended.

Moreira, D.; Simionato, C.G.; Dragani, W.; Cayocca, F., and Luz Clara Tejedor, M., 2016. Characterization of bottom sediments in the Río de la Plata estuary.

Bottom sediments and surface water samples were collected in the intermediate and outer Río de la Plata (RDP) estuary, South America, during 2009–10, in six repeated cruises, with 26 stations each. Samples were processed for grain size and for water and organic matter content. The aim of this work is to analyze this new data set to provide a comprehensive and objective characterization of the bottom sediment distribution, to study the composition, and to construct a conceptual model of the involved physical mechanisms. Principal components analysis is applied to the bottom sediment size histograms to investigate the spatial patterns. Variations in grain size parameters contain information on possible sediment transport patterns, which were analyzed by means of trend vectors. Sediments show a gradational arrangement of textures: sand dominant at the head, silt in the intermediate estuary, and clayey silt and clay at its mouth. Textures become progressively more poorly sorted offshore, and the water and organic matter content increase and seem to be strongly related to the geometry and the hydrodynamics. Along the northern coast of the intermediate RDP, well-sorted medium and fine silt predominates, whereas along the southern coast, coarser and less sorted silt prevails from differences in tidal currents, in the tributaries' water pathways, or both. Around Barra del Indio, clay prevails over silt and sand, and the water and organic matter content reach a maximum, probably because of flocculation and reduction of the currents. Immediately seaward of the bottom salinity front, net transport reverses its direction, and well-sorted, coarser sand from the adjacent shelf dominates. Relict sediment is observed between the Santa Lucía River and Montevideo, consisting of poorly sorted fine silt and clay. The inferred net transport suggests convergence at the bottom salinity front, where the limit of the estuarine deposits is observed.

Tano, R.A.; Aman, A.; Kouadio, K.Y.; Toualy, E.; Ali, K.E., and Assamoi, P., 2016. Assessment of the Ivorian coastal vulnerability.

Climate change and variability of associated factor, such as sea-level rise, could increase exposure of the Gulf of Guinea coastal area to coastal erosion and inundation. The processes (relative sea-level rise, tidal range, and wave height) and state factors (geomorphology, coastal slope, and coastline change rate) have been analyzed to evaluate the vulnerability index of the Ivorian coastal area. This study area was divided into three zones based on geomorphology. A coastal vulnerability index (CVI) was computed for each zone according to six factors describing its variability. Results indicate that the entire Ivorian coastal zone falls into a moderate-risk category. The relative vulnerability of the different sections depends strongly on the geomorphology and on wave energy factors. This vulnerability increases spatially westward taking account of their CVI values. The CVI will undoubtedly increase with predicted sea-level rise. The result of this study could provide wide coastal information to coastal managers and Ivorian government coastal people and help to protect the coastal ecosystem.

Filipot, J.-F., 2016. Investigation of the bottom-slope dependence of the nonlinear wave evolution toward breaking using SWASH.

Numerical simulations of irregular waves propagating over planar beaches with slopes varying from 1 to 10% are performed with the Simulating WAves till SHore (SWASH) model. As reported in observational studies, waves shoaling over steep (mild) slopes break in shallower (deeper) water. The bottom slope is found to influence the cumulative contribution of the triad wave interactions to the wave spectrum. The triad contribution affects wave skewness and wave asymmetry at breaking point. This consolidates findings reported in previous field studies and has significant implications for coastal applications.