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Through alteration of wave-generating atmospheric systems, global climate changes play a fundamental role in regional wave climate. However, long-term wave-climate cycles and their associated forcing mechanisms remain poorly constrained, in part due to a relative dearth of highly resolved archives. Here we use the morphology of former shorelines preserved in beach-foredune ridges (BFR) within a protected embayment to reconstruct changes in predominant wave directions in the Subtropical South Atlantic during the last ~3000 years. These analyses reveal multi-centennial cycles of oscillation in predominant wave direction in accordance with stronger (weaker) South Atlantic mid- to high-latitudes mean sea-level pressure gradient and zonal westerly winds, favouring wave generation zones in higher (lower) latitudes and consequent southerly (easterly) wave components. We identify the Southern Annular Mode as the primary climate driver responsible for these changes. Long-term variations in interhemispheric surface temperature anomalies coexist with oscillations in wave direction, which indicates the influence of temperature-driven atmospheric teleconnections on wave-generation cycles. These results provide a novel geomorphic proxy for paleoenvironmental reconstructions and present new insights into the role of global multi-decadal to multi-centennial climate variability in controlling coastal-ocean wave climate. A.P.S. and A.H.F.K. acknowledge the Brazilian Ministry of Environment for funding through the SMC-Brazil project. A.H.F.K. acknowledges the Rede Clima, INCT MarCOI “Oceanografia Integrada e Usos Multiplos da Plataforma Continental e Oceano Adjacente—Centro de Oceanografia Integrada (COI)”, CNPQ (PQ2- CNPQ 301963/2015-0, PQ1D CNPQ 301597/2018-9, CNPQ 441545/2017-3) and, CAPES Brazil-Finance Code 001 and Capes/PROEX 88881.146046/2017-01 for financial support. F.J.M. acknowledges the funding from the Spanish Ministry of Science and Innovation through the project PID2019-107053RB-I00. A.P.S. acknowledges the CESM1(CAM5) Last Millennium Ensemble Community Project and supercomputing resources provided by NSF/CISL/Yellowstone. C.J.H. acknowledges that this paper is Contribution 3957 of the Virginia Institute of Marine Science, William & Mary.

This research uses a process-based model (Delft3D), validated with measured wave data, to investigate the controls that a cuspate shoreline and its associated submerged morphology have on wave generation, propagation, and attenuation within a large elongated lagoon (Lagoa dos Patos, Brazil). A method based on the Energy-Flux-Method was applied to the historical wind dataset to define representative wind cases to be used as forcing conditions in the model. The results show that, during extreme wind conditions, the spits dissipate wave energy in the lagoon. This (wave attenuation and the wave sheltering effect) controls the stability of the adjacent coastline. The wave attenuation varies between 18% and 46% along the submerged spit depending on the crest width and the amplitude of the incident waves. Waves are mainly attenuated in the proximal and central portions of the spits where the spits are wider, resulting in a reduced transmitted energy to the adjacent coastline, while larger waves are also attenuated on the distal end of the spits. The degree of attenuation depends on the direction of wave generation, the respective fetch, the spit width, and the water depth. A strong relationship of mutual co-adjustment between the morphology and the wave field results in a very low occurrence of oblique wave angles of incidence, especially for waves propagating across the long lagoon axis. Furthermore, the wave attenuation over the spits is also responsible for its progressive erosion, which, from decades to centuries, may lead to an increase of changes on the lagoon shorelines.

The impacts of severe storms on the coastal zone, combined with rapid population growth in this area, has made coastal risk management an urgent need. However, integrated risk assessment can be a challenging task for many locations worldwide, as it normally requires the use of a large amount of data. The Coastal Risk Assessment Framework phase one (CRAF1), is a recently proposed analytical scheme based on empirical models and spatial analysis that combines different indicators to identify storm-induced hotspots. The methodology, however, requires accurate data at the regional scale and was conceived and validated for the European region. In this study, we show that this approach can be applied, with some simplifications, on data-poor areas, allowing the identification of hotspots considering one or multiple hazards. Here, the coastal risk was assessed for erosion and coastal flooding events with return periods of 10 and 50 years on the Santa Catarina Central Coast. The study area is characterized by the occurrence of storm-induced impacts that historically cause disruption and damage to local communities. Although the components of risk have been assessed using various methods along this sector, to date, no integrated risk analysis has been presented in probabilistic terms. Predicted scenarios for the Santa Catarina Central Coast suggest that extreme episodes may cause several impacts, exposing urban settlements as well local road systems, especially in the municipalities of Tijucas and Florianópolis. The results show that the CRAF1 is an appropriate approach for a first-level risk analysis, even when implemented with poor data resolution, as it effectively points to some of the most vulnerable stretches detected in the study area.

A new mixed turbidite-contourite system is described in the northern Campos Basin, southeastern Brazilian margin. This system is developed in a middle slope setting and was formed through non-synchronous interaction between the turbidity current and a contour current in the same stratigraphic interval (Miocene). Different depositional cycles were accounted based on their diagnostic seismic features. Seismic attributes, seismic facies, and isochron maps were used to identify alternating cycles of downslope and alongslope processes in the study area, along with the intermediate stage with features from both processes (mixed system). Seismic units were then associated with the dominant type of current. Depositional processes resulted from alongslope current activity can be distinguished from the downslope current activity, based on the acoustic characteristics (root-mean-square (RMS) amplitude values), internal architecture, and external geometry pattern. While alongslope currents deposits consist of mainly low RMS amplitude values clinoforms with an alongslope trend; the downslope gravity deposits present high-amplitude or chaotic seismic facies, usually higher values of RMS amplitude, channel or channel-lobe features, erosive surfaces, and a basinward depositional trend. The first and oldest seismic unit (S1) was interpreted as a dominantly alongslope system, with aggrading sigmoidal clinoforms and high-frequency, low-amplitude reflections commonly associated with fine-grained sedimentary deposits, typical of a plastered drift. Basinward mass transport deposit derived from previous drift instability are often identified. Seismic unit S2 represents the intermediate stage where both gravity-driven and along-slope currents act asynchronously. It is referred to as a mixed turbidite-contourite sequence that shows high-amplitude sediment waves migrating upslope and a moat feature carved in its upslope front. The interfingering between high- and low-amplitude reflectors, distal chaotic facies, together with sediment waves and a channel moat, points to a sand-rich deposit reworked by northward-flowing contour currents. Seismic units S3 and S4 show downslope features with chaotic facies (S3) and paleochannels with coarse basal lag deposits interpreted after the high RMS amplitude values (S4). In S4, a series of long-lived submarine channels formed. The last seismic unit, S5, referred to as the second plastered drift sequence, is marked by low-amplitude clinoforms that thin basinward. Important information on the paleocurrents' direction was also made based on the final deposits display (e.g. terraces, sediment waves, paleochannels), where a northward-flowing bottom current was assumed. Research on alternating dominant processes and transitional stages or mixed depositional systems may provide a better understanding of deep-water depositional processes. Because these processes do not always fit previous depositional models that are mainly described for synchronous systems, new insights on cyclic non-synchronous mixed systems can improve our understanding of how mixed systems are organized through time and space. We can also determine which were the dominant processes that controlled the sedimentation by indicating periods where the margin was mostly submitted to sediment transfer from continent to the basin and periods where the oceanic currents prevailed by redistributing sediments along the isobaths and replacing the axis of downslope transfer conduits. Setting new models on cyclic deposits and intermediate stages can have a future economic impact on potential hydrocarbon reservoir architecture.

This paper describes the overpassing process using a case study from southern Brazil, that present a decadal pulse of sediment entering in the system. A transgressive dune field extends across a headland from Santinho beach to Ingleses beach. Analysis of precipitation data (1961-2014), wind direction and speed (1964-2014), aeolian drift potential (DP), aerial photographs/satellite images (between 1938 and 2016) and morphological data (2002, 2010 and 2014) make it possible to analyze the decadal-scale dune field evolution. The wind historical data showed southern wind as the stronger, moving the dune crests to north. The rainfall analysis presents an increasing trend leading to a decrease in drift potential and favors dune stabilization by vegetation growth. There is a decadal pulse of sediment inputs to the system, as well. The northern sector of Santinho beach has a positive budget and provides about 6,000m³/year of sediment to the foredune. Then, with southern winds, the sediment migrates into the dune field (about 3,000-5,000m³/year) reaches Ingleses by overpassing, ensuring a positive sediment budget for the system that occurs at east side of the Ingleses beach.

Variability in global wave climate has been observed to occur in response to climate changes influencing the wave-generating zones. This highlights the need for an improved understanding of long-term wave-climate cycles, considering the multi-decadal variability of the atmospheric patterns and large-scale climate drivers. In this study, a novel use of the morphology of former shorelines preserved in beach-foredune ridges was applied to reconstruct changes in predominant wave directions in the Subtropical South Atlantic during the Late Holocene. A 3km wide semi-continuous sequence of beach-foredune ridges preserved within the Pinheira Strandplain (Santa Catarina State, Brazil) was mapped in order to extract the orientation of the former shorelines and derive a 3000-year record of inferred mean wave direction. The mean wave direction series was compared to ~1000 years of decadal means of mid-latitude mean sea-level pressure gradients (∆MSLP) and zonal westerly wind velocities estimated from the CESM1-CAM5 “Last Millennium Ensemble (LME)”, and to 2000 years of air-surface temperature anomalies for Southern Hemisphere. Results showed that multi-centennial cycles of oscillation in predominant wave direction occurred in accordance with stronger (weaker) South Atlantic mid-latitude mean sea-level pressure and zonal westerlies winds, favouring wave generation zones in higher (lower) latitudes and consequent southerly (easterly) wave climate dominance. It was identified the Southern Annular Mode as the main climate driver responsible for these changes, responding for 43% of the variance in the Subtropical South Atlantic atmospheric patterns in the last 1000 years. Long-term variations in interhemispheric air-surface temperature offsets, coincident with oscillations in wave direction, may have influenced wave-generation patterns similarly to the seasonal behaviour observed over recent decades. Periods of relatively warmer Southern Hemisphere (SH) as compared with Northern Hemisphere (NH) (e.g., during 400–800 CE and the Little Ice Age) favours the predominance of easterly wave energy flux along the eastern South American coast, whereas periods with equivalent NH-SH temperature anomalies (e.g., Medieval Warm Period) or with colder relative SH (last ~150 years) support an increase in the influence of the southerly wave energy flux over the South Atlantic. These results provide a novel geomorphic proxy for paleoenvironmental reconstructions and present new insights into the role of multi-decadal to multi-centennial climate variability on controlling coastal ocean wave climate.

Investigations of headland sand bypassing are still an under-reported subject in the literature. This paper aims to understand the contribution of currents forced by different mechanisms such as tides, winds (i.e. local wind acting over the ocean surface generating currents, without considering wave generation) and waves (as they approach/break on the coast) to headland sand bypassing. The study was carried out in an area comprising a series of seven headlands with varying wave exposure due to changes in shoreline orientation and increasing tidal influence close to a relatively large bay. This paper uses a calibrated and validated process-based model (Delft3D) to simulate a series of scenarios including spring and neap tides during flood and ebb conditions and a range of wind and wave scenarios that encompass both average and extreme conditions. The results indicate that waves are the main driving force for the headland bypassing as they transport sand at rates two orders of magnitude higher than tide- or wind-driven sediment transport. The tide-driven currents can only transport sediment during spring tides in locations where the currents are intensified. It is also demonstrated that the wave direction plays an important role in sediment transport. In exposed areas with larger headlands a combination of wave directions is required to first transport sediment offshore (out of the beach) and secondly to transport sediment alongshore and back to the next beach. Whereas in areas with little variation in wave direction exposure, the same oblique wave direction is responsible for the entire headland bypassing process. This is the first time the contribution of tide-, winds- and wave-generated sediment transport to headland bypassing have been studied.

The inner continental shelf (0–50 m water depth) off Santa Catarina, southern Brazil was investigated using seismic stratigraphic methods to identify and interpret the major seismic stratigraphic units and to reconstruct the late Quaternary evolution of the inner shelf and coast. The stratigraphy comprises a bedrock basement overlain by a thick (> 30 m) unit that comprises, in the distal portion, laminated muds and sands, and in the coast-proximal zone, offlapping deltaic deposits, whose upper surface has been reworked to form alongshore-prograding barrier spits. Deposition of this unit is tentatively attributed to sea levels (− 20 m MSL) during the late Pleistocene (MIS 5a, or 5c). A normal fault in the muddy units with a vertical offset of 3.5 m indicates episodic tectonic activity. Cut into this unit is a profusion of incised valleys, associated with sea level fall ultimately to − 120 m at the last glacial maximum (LGM). The associated subaerial unconformity is only preserved close to shore, where it has escaped subsequent wave ravinement. This, coupled with the well-preserved incised valleys implies the underlying substrate to be weakly cohesive material (mud). The incised valleys display a variety of infilling sediments interpreted variously as basal fluvial sediments, estuarine basin infill muds and marginal bar or barrier-associated sands deposited during the postglacial marine transgression. During a sea level stillstand at ca. -50 m, a 3.5 km-wide planar surface was cut into the unconsolidated coastal plain sediments forming a terrace on which a thick sequence of sands accumulated. This unit is regionally developed and the acoustic signature implies it to comprise littoral sand including a large aeolianite component. The accumulation of sand on this mainland beach/dune system is attributed to establishment of a mature littoral system with strong longshore drift. The fact that it rests on an erosional surface that truncates incised valleys, suggests the unit to be Holocene in age. It is interpreted to have been deposited during a still stand in the Holocene and to have undergone aggradation and cementation until it was overstepped by sea-level rise. Its surface and the coastal plain to landward were then subject to wave ravinement and a thin (ca. 5–6 m) layer of modern marine sands was deposited on the eroded surface. Sea-level rise continued to the regional glacio-isostatic highstand of ca. 5.5 m, after which regressive strandplains developed in response to a renewed mature longshore drift system similar to that prevailing during the − 50 m stillstand of sea level. In the intervening period, rapid shoreline translation over the low gradient surface inhibited the development of the longshore transport system. The three shoreline systems identified show marked differences that relate to sea level change and the influence of the underlying topography. Shoreline 1 (Pleistocene highstand) developed by localised wave-reworking of delta deposits and involved a series of alongshore-prograding barrier spits on a shoreline of alternating high-relief bedrock and littoral sands in coastal re-entrants. Shoreline 2 (− 50 m) was a major accumulation of beach and dune sand deposited as a mainland-attached beach dune system on a low-lying coastal plain environment. Shoreline 3 (the modern coast) comprises a series of headland-embayment beaches, strandplains and transgressive dunes with a strong bedrock control and a well-developed longshore drift system delivering sediment northward.

This chapter reviews the status of headland bypassing (HB) and headland overpassing (HO) research. These processes are fundamental components of the many headland-bound coastal sediment budgets, as they can connect the coastal cells and support the continuity of the sediment transport around or over headlands. This review starts by presenting an overall definition and evolution of the research in this topic. This is followed by the main components of headland bypassing and overpassing (HB&O) processes, addressing the sediment availability, geomorphological constraints and the driving forces. It then describes the HB&O conceptual models and the methods used to investigate bypassing and overpassing. The chapter concludes with examples of HB&O concepts and a discussion on the perspectives, challenges and outlook for the research agenda into headland sediment bypassing and overpassing.

Knowledge of the characteristics of storm surges is of paramount importance for an effective coastal hazard risk assessment. The vast Majority of storm surges in southern Brazil are generated by extratropical cyclones. In this context, this study focuses on spatial and temporal analysis of storm surges caused by the cyclones within a 30-year period. The wind and pressure from CFSv2 data were analyzed from 1979 to 2010 time span, with a time lag of 9 h identified for pressure and 26 h for wind stress. A multiple linear regression model was then employed to estimate the expected intensity of the storm surge. The results suggest that the model represented 82% of the variations in the storm surge levels. The accuracy of the surge predictions was validated by the recorded storm surges using tide gauge data for Itajai port. The agreement between the modelled and the observed values were considered good by explaining 74% of the variations in the storm surge. Finally, Analysis of future scenarios of 1-, 10-, 50- and 100-return period revealed that positive storm surge events may be higher, increasing coastal risks in the coastal zone of southern Brazil.

A user-friendly system designed to understand local littoral processes and design/evaluate coastal interventions, named the Coastal Modeling System (SMC e ) is presented. The system, which comprises a set of numerical models, state-of-the-art methodologies and numerical databases, is prepared to provide a method for coastal practitioners, researchers and decision-makers to address coastal issues, such as erosion and flooding or to evaluate coastal defense structures. The system incorporates a method to transfer numerically generated, calibrated and validated wave series to the surf zone; to estimate the sediment littoral drift by means of up-to-date formulations; and to estimate the flooding level and impacts such as those produced by climate change. In this paper, these skills are detailed. The system, which is adaptable to any coastal region, was implemented for the Brazilian coast (SMC-Brasil). The implementation includes databases and methodological adaptations to local characteristics, a dissemination plan and the development of several study cases.

CASSIE is an open-source web tool for automatic shoreline mapping and analysis using satellite imagery ( www.cassiengine.com ). This tool was built in JavaScript, using Google Earth Engine (GEE) API, and can be applied to any coastal region on Earth where a boundary between water and land exists. CASSIE use the Landsat and Sentinel-2 satellite imagery, freely available from GEE, and implements an automatic shoreline detection using the normalized difference water index (NDWI) together with Otsu image segmentation algorithm. The satellite-derived shorelines are analysed for a set of user-defined cross-shore transects along which several statistical analyses are performed. Comparisons of the CASSIE-derived shorelines and rate of changes with state-of-the art methods show that the products from this tool have sub-pixel accuracy. The new concept of big-data cloud-based computing and storage platform (GEE), together with a user-friendly interface and high level of automation makes of CASSIE a complete tool to support a wide variety of studies and applications where the knowledge of the shoreline behaviour is fundamental.

Highlights • A new description of a non-synchronous Mixed Turbidite-Contourite System. • Alternated and cyclic deposits of down-slope and along-slope processes with a transitional stage of flow interaction. • Dominant flow depositional systems identification based on seismic response. • How mixed systems are organized through time and space. Abstract A new mixed turbidite-contourite system is described in the northern Campos Basin, southeastern Brazilian margin. This system is developed in a middle slope setting, and was formed through non-synchronous interaction between the turbidity current and a contour current in the same stratigraphic interval (Miocene). Depositional cycles were differentiated based on diagnostic seismic features. Seismic attributes, seismic facies, and isochron maps were used to identify alternating cycles of downslope and alongslope processes in the study area, along with the intermediate stage with features from both processes (mixed system). Seismic units were then associated with the dominant type of current. Alongslope current activity can be distinguished from the downslope current based on its acoustic characteristics (mainly low root-mean-square (RMS) amplitude values), internal architecture (clinoforms), and external geometry pattern (alongslope trend). On the other hand, downslope gravity currents develop deposits with high-amplitude or chaotic seismic facies, usually higher values of RMS amplitude, channel or channel-lobe features, erosive surfaces, and a basinward depositional trend. The first and oldest seismic unit (S1) was interpreted as a dominantly alongslope system, with vertical aggrading sigmoidal clinoforms and high-frequency, low-amplitude reflections commonly associated with fine-grained sedimentary deposits, typical of a plastered drift, along with a basinward mass transport deposit (MTD) from previous drift instability. Seismic unit S2 represents the intermediate stage where both gravity-driven and along-slope currents act asynchronously. Its is refered to as a mixed turbidite-contourite sequence that shows high-amplitude sediment waves migrating upslope and a moat feature that is carved in its upslope front. The interfingering between high- and low-amplitude reflectors, distal chaotic facies, together with sediment waves and a channel moat, points to a sand-rich deposit reworked by northward-flowing contour currents. Seismic units S3 and S4 show downslope features with chaotic facies (S3) and paleochannels with coarse basal lag deposits (high RMS amplitude values) (S4). In S4, a series of long-lived submarine channels formed. Last, seismic unit S5, referred to as the second plastered drift sequence, is marked by low-amplitude clinoforms that thin basinward. At the seafloor, submarine channel banks (formed at S4) covered by fine sediment deposits (from S5) show asymmetrical features with a slight northward depositional trend, indicating a northward-flowing bottom current, as the deposits are known to pile up in a downcurrent trend. Important information on the paleocurrents' direction was also made based on the final deposits display (e.g. terraces, sediment waves, paleochannels). Research on alternating dominant processes and transitional stages or mixed depositional systems, with both turbidites and contour currents, may provide a better understanding of deep-water depositional processes. Because these processes do not always fit previous depositional models that are mainly described for synchronous systems, new insights on cyclic non-synchronous mixed systems can improve our understanding of how mixed systems are organized through time and space. Being able to determine which were the dominant processes that controlled the sedimentation by indicating periods where the margin was mostly submitted to sediment transfer from continent to the basin and periods where the oceanic currents prevailed by redistributing sediments along the isobaths and replacing the axis of downslope transfer conduits. Setting new models on cyclic deposits and intermediate stages can have a future economic impact on potential hydrocarbon reservoir architecture.

In an era of global rising sea level, quantifying future shoreline behaviour is a key societal concern. The potential for dramatic shoreline change via overstepping or barrier disintegration on barrier-lagoon coasts as a result of future rapid sea level rise has been considered by various authors, but documented examples of barrier overstepping generally involve either coarse grain sizes or early diagenesis as beachrock. Where overstepping has been inferred, the overstepped barrier is seldom preserved. Using high resolution seismic data we describe the mid-Holocene overstepping of a sandy coastal barrier system and subsequent geomorphological changes that ultimately transformed it into a strandplain fronted by a muddy shoreface. This complete change in character is interpreted in the context of rapid sea level rise (tentatively linked to the 8.2 ka event) during which the former sandy shoreface-barrier was overstepped and decoupled from the contemporary shoreline, leaving the latter sand-starved. Upon overstepping, the wave-influenced shoreline was displaced rapidly to the landward margin of the former lagoon. Preservation of the overstepped uncohesive sandy barrier is attributed to the relatively wave-sheltered location, rapid sea level rise and rapid burial by shoreface sediments. This situation provides an insight into the conditions under which overstepping occurs, and thereby, the future response of barrier-lagoon systems to predicted rapid rates of future sea level rise.

Vieira da Silva, G.; Muler, M.; Prado, M.F.V.; Short, A.D.; Klein, A.H.F., and Toldo, E.E., Jr., 2016. Shoreline change analysis and insight into the sediment transport path along Santa Catarina Island north shore, Brazil. This paper presents a shoreline change analysis applied to identify the sediment transport path involving nine adjoining beaches, including dunes and spits, located along the microtidal eastern and northern shores of Santa Catarina Island (Brazil) and extending 50 km from Barra-Mocambique to Daniela. A data set was comprised of aerial images from 1957, 1978, 1998, 2002, 2007, and 2010, and the 2012 shoreline position measured with real-time kinematic GPS, topobathymetric data set, and a 60-year water-level time series. The images were rectified and the shoreline position for each year was extracted. The average errors (ranging from 1 to 9.8 m) of the rectification process as well as the horizontal tide-related errors (varying from 8.3 ± 2.6 m to 14.9 ± 0.6 m) were calculated wi...

Thick bay-fill sequences that often culminate in strandplain development serve as important sedimentary archives of land–ocean interaction, although distinguishing between internal and external forcings is an ongoing challenge. This study employs sediment cores, ground-penetrating radar surveys, radiocarbon dates, palaeogeographic reconstructions and hydrodynamic modelling to explore the role of autogenic processes – notably a reduction in wave energy in response to coastal embayment infilling – in coastal evolution and shoreline morphodynamics. Following a regional 2 to 4 m highstand at ca 5·8 ka, the 75 km2 Tijucas Strandplain in southern Brazil built from fluvial sediments deposited into a semi-enclosed bay. Holocene regressive deposits are underlain by fluvial sands and a Pleistocene transgressive–regressive sequence, and backed by a highstand barrier-island. The strandplain is immediately underlain by 5 to 16 m of seaward-thickening, fluvially derived, Holocene-age, basin-fill mud. Several trends are observed from the landward (oldest) to the seaward (youngest) sections of the strandplain: (i) the upper shoreface and foreshore become finer and thinner and shift from sand-dominated to mud-dominated; (ii) beachface slopes decrease from >11° to ca 7°; and (iii) progradation rates increase from 0·4 to 1·8 m yr−1. Hydrodynamic modelling demonstrates a correlation between progressive shoaling of Tijucas Bay driven by sea-level fall and sediment infilling and a decrease in onshore wave-energy transport from 18 to 4 kW m−1. The combination of allogenic (sediment supply, falling relative sea-level and geology) and autogenic (decrease in wave energy due to bay shoaling) processes drove the development of a regressive system with characteristics that are rare, if not unique, in the Holocene and rock records. These findings demonstrate the complexities in architecture styles of highstand and regressive systems tracts. Furthermore, this article highlights the diverse internal and external processes and feedbacks responsible for the development of these intricate marginal marine sedimentary systems.

Gomes da Silva, P.; Dalinghaus, C.; Gonzalez, M., Gutierrez, O., Espejo, A., Abascal, A.J., and Klein, A.H.F., 2016. Estimating flooding level through the Brazilian coast using reanalysis data. 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. 1092 - 1096. Coconut Creek (Florida), ISSN 0749-0208. This paper presents an estimative of coastal flooding level values distribution along the Brazilian coast by using reanalysis data and by simulating wave propagation with Snell approximation. The coast was divided into 24 zones and flooding levels series were calculated for each one. Mean and extreme distribution show higher flooding levels occurring in northern coast (3 m higher than beaches in central coast) followed by the southern coast (1 m higher than central coast). High values obtained on north region were associated with greater tidal elev...

Wave runup is one of the most critical parameters contributing to coastline flooding and shoreline change. Many formulas have been developed to empirically predict wave runup characteristics. However, large errors are still associated to these estimates, feeding a debate on the best approach to describe runup through simple parameterizations. In this work we present a comprehensive review on runup, setup and swash empirical models. We use a large database of field measurements to verify the predictive capability of recent formulas, addressing possible sources of variability. We identify the effect of the nearshore bathymetry as an important factor missing in empirical predictors and examine this issue through an analysis of runup simulated with the SWASH model over different barred and linear bathymetries. The details of the submerged beach profile affect estimates, especially with respect to setup values. The lack of standardization in measuring, post-processing and sharing runup data, limits the application of previous published databases on new analysis. We list a set of recommendations that can be used as guidelines for new measurements to broaden the applicability of the datasets in future studies. Finally, we discuss the remaining questions that still need to be further explored.

The present work consists of processing data obtained during the SCARA01A-2D program from the records of the Brazilian National Petroleum Agency (ANP). The chosen prospect is called 0247_Caravela_1993 and was used to observe the dynamics of the water column in the platform region and slope of Santa Catarina Brazilian coast. The processing used by seismic oceanography seeks to highlight thermohaline structure reverberations, which have smaller amplitude compared to those that are typical of reflectors associated with substrate. Since in some cases weak amplitude reflections and noise have the same magnitude, it is necessary to conduct a study to identify whether the noise components are creating artifacts in the image that are not related to the thermohaline structure in the water column. Basic steps of seismic data processing, such as frequency filtering, velocity analysis, normal moveout correction and stacking are followed to obtain the image of the water column. This work shows the spiking deconvolution and the deconvolution with regularization applied to thoses seismic data. The aim was to get the reflectivity function and thus distinguish artifacts in the water column.

This work presents a methodology for using legacy seismic data from oil and gas industry for low-frequency acoustic imaging (up to 200 Hz) of internal oceanic structure. The procedure to obtain these images is called seismic oceanography and is an emerging tool for a large-scale analysis of the ocean physical properties. The collection of seismic data from the oil industry is used for seismic oceanographic processing as they have both similar survey configuration requirements for their data acquisition. The dataset used to define the methodology was obtained with the Brazilian Oil Exploration Database (BDEP). The presented results use the 0247 Caravela1993 line. A robust methodology has been detailed that allows to quickly identify if the dataset could provide useful information for a deeper seismic oceanographic analysis. The processed results indicate that the seismic oceanography processing can be applied in legacy industry data and that there are significant information in the seismic line used that could contribute to physical oceanography research.

This paper presents a new approach for estimating run-up on embayed beaches based on a study of the microtidal coast of Itapocorói Bay, Southern Brazil using the surf similarity parameter and wave height at break location. The four step methodology involved: 1) direct wave measurement (34 days), wave run-up measurement (19 days at 7 points within the bay), measurement of bathymetry and beach topography in the entire bay; 2) tests on available formulae to calculate wave run-up; 3) use of the SWAN spectral wave model to simulate wave parameters at breaking at each wave run-up measurement point and; 4) development of a new formula/approach to assess wave run-up on embayed beaches (in both exposed and protected areas). During the experiments the significant wave height varied from 0.5 m to 3.01 m, the mean wave period from 2.79 s to 7.76 s (the peak period varied between 2.95 s and 17.18 s), the mean wave direction from 72.5° to 141.9° (the peak direction varied from 39.2° to 169.8°) and the beach slope (tan β) from 0.041 to 0.201. The proposed formula is in good agreement with measured data for different wave conditions and varying degrees of protection. The analysis demonstrates that although R² varies from 0.52 to 0.75, the wave run-up distribution over the measurements agreed well with the proposed model, as shown by quantile-quantile analysis (R²=0.98 to 0.99). The errors observed in individual cases may be related to errors of measurements, modeling and to non-linear processes in the swash zone, such as infragavity waves. RESUMO Este artigo tem o objetivo de estimar o run-up em praias de enseada a partir de estudo realizado na Enseada do Itapocorói, localizada em uma costa de micromarés no sul do Brasil utilizando o parâmetro de similaridade de surf (surf similarity parameter) e altura de ondas no ponto de quebra. A metodologia aplicada foi dividida em quatro etapas: 1) medição direta de ondas (34 dias), medidas de wave run-up (19 dias em 7 pontos da baía), medições topo-batimétricas; 2) testes com as fórmulas disponíveis na literatura para cálculo do run-up; 3) uso do modelo espectral SWAN para simular a propagação das ondas e obter os parâmetros de ondas no ponto de quebra no momento das medições do run-up e; 4) desenvolvimento de uma nova abordagem para estimar o run-up em praias de enseada (aplicável às áreas protegidas e expostas da enseada). Os resultados demonstram que, durante os experimentos, a altura significativa de onda variou entre 0,5 e 3,01 m, o período médio entre 1,79 e 7,76 s (o período de pico entre 2,95 e 17,19 s), a direção média entre 72,5° e 141,9° (a direção de pico entre 39,2° e 169,8°) e a declividade da face da praia (tan β) entre 0,041 e 0,201. A fórmula proposta apresenta boa concordância com os dados medidos para diferentes condições de ondas e graus de proteção da praia. Como conclusão destaca-se que, apesar do R² variar entre 0,52 e 0,75, a distribuição das medições de run-up apresentou boa concordância com o modelo proposto, como demonstrado pela análise quantil-quantil (R²=0,98 a 0,99). Os erros observados em casos individuais podem estar relacionados a erros das medições, do modelo e aos processos não lineares presentes na zona de espraiamento, como as ondas de infragravidade.

In order to decrease the simulation time of morphodynamic models, often-complex wave climates are reduced to a few representative wave conditions (RWC). When applied to embayed beaches, a test of whether a reduced wave climate is representative or not is to see whether it can recreate the observed equilibrium (long-term averaged) bathymetry of the bay. In this study, the wave climate experienced at Milagro Beach, Tarragona, Spain was discretized into ‘average’ and ‘extreme’ RWCs. Process-based morphodynamic simulations were sequenced and merged based on ‘persistent’ and ‘transient’ forcing conditions, the results of which were used to estimate the equilibrium bathymetry of the bay. Results show that the effect of extreme wave events appeared to have less influence on the equilibrium of the bay compared to average conditions of longer overall duration. Additionally, the persistent seasonal variation of the wave climate produces pronounced beach rotation and tends to accumulate sediment at the extremities of the beach, rather than in the central sections. It is, therefore, important to account for directional variability and persistence in the selection and sequencing of representative wave conditions as is it essential for accurately balancing the effects beach rotation events.

Elongate, rock-framed Santa Catarina Island partly encloses a low-energy marine embayment that communicates with the ocean via narrow, rock-bounded inlets with ebb and flood-tide deltas. The bay shoreline consists of low-energy sandy beaches, strandplains, mangroves and bayhead deltas while the exposed Atlantic shoreline comprises a series of headland-embayment littoral cells in a linked, north-directed longshore drift system. New and previously published seismic stratigraphic investigations enable assessment of the palaeogeographic/geomorphic evolution of the area since the early Holocene. At a sea level of ca. −50 m a sandy mainland-attached shoreline complex (dune and beach) developed on a coastal plain setting some 6–7 km offshore of the present shoreline. North of the island, a barrier island and tombolo were formed in a coastal re-entrant adjacent to the northern entrance to Florianopolis Bay. The open coast beach/dune system was overstepped by rapid sea-level rise during MWP-1B whereas the barrier island and tombolo continued to accrete until MWP-1C when they too were overstepped. The back-island embayment contains up to 40 m of sediment overlying an irregular bedrock surface. It was initially flooded during MWP-1C and the early muddy sedimentation suggests a distal, sheltered marine embayment. The subsequent development of many large bioherms on bedrock and mud suggests a change to more fully marine conditions as sea-level continued to rise. In the North Bay, these were subsequently enveloped by tidal dunes migrating north from the mid-bay. The vertical stacking of 3-D and 2-D sandy bedforms suggests that a tidal strait had developed with strong tidal currents radiating from a constriction in the vicinity of modern Florianopolis City. The strong tidal currents may be linked to the Holocene sea-level high that is well documented for this region. A fall in sea level from this highstand, coupled with accumulation of tidal strait sediments, reduced the tidal prism and strength of tidal currents in the bay. At the same time, regressive beachridge plains developed in open coast and bay environments. This coincided with development of the contemporary tidal inlet complexes at the north and south outlets of the bay. As a consequence, the upper surface of the tidal strait sand deposits experienced tidal ravinement and the bay switched to a sheltered back-barrier environment dominated by deposition of mud and silt which blanket the contemporary bay floor. The tidal inlets sequestered sand from the littoral drift system in ebb and flood-tide deltas, which created breaks in the longshore drift system, causing littoral sediment to accumulate at the north of the island in a series of spits, and promoting strandplain development south of the island.

The development of lagoon sandy spits is dependent on sediment supply (mainly through longshore transport) and is often related to erosion of updrift beaches under high-angle waves. This paper provides an understanding of the short- to medium-term shoreline evolution of three symmetrical lagoon sandy spits and the related erosion of the adjacent bay beaches of Lagoa dos Patos, Brazil. To do so, two of the most widely used methods to quantify shoreline changes were applied: the transects-from-baseline method and the change polygon method. A historical analysis of the shoreline movement of approximately three decades (1984–2013), was carried out, aiming to track the source of sediments to the spits. Alternate phases of shoreline stability, deposition, and recession (less frequent) in short time intervals (years) showed correlation with the El Nino–Southern Oscillation and Southern Annular Mode indexes. Shoreline stability along beaches in the medium term (60.4% of Arambare and 73.9% of Graxaim beaches, by the linear regression rate calculation), together with the very low average shoreline change rate of +0.7 m y–1 found using both methods, demonstrates that the sediment supply to the spits has been significantly reduced in the past three decades. Furthermore, the large-scale subaqueous portions of the spits are under wave-induced sedimentary reworking accompanied by the up-building of sandbanks from the submerged bars, followed by its landward migration and merging to the spit's shoreline. These results suggest that the spits of Lagoa dos Patos have their growth limited once the amount of sediment supply has been significantly reduced.

This paper presents the spatial distribution of shallow gas structures and classifies them on the basis of two different data sets of CHIRP seismic records, one from the Conceição Lagoon (CL) and the other from North Bay (NB), both on Santa Catarina Island, Southern Brazil. Side scan sonar data from the CL were used to facilitate the understanding. The sub bottom (SB) seismic data were processed and interpreted by means of the SeisPrho software, the side scan sonar (SSS) data by SonarWiz5 software and the spatial extension being measured with the help of GIS. The shallow gas structures were defined in accordance with their shapes in the seismic recordings (echo-character). At the CL, shallow gas accumulations were found in the form of seepages and features presenting shallow gas structures between the surface and 8.20 ms (around 12.3 m). Accumulations of gas were found in the form of Acoustic Blanking with Acoustic Plume, and also Black Shadows. Pockmarks were found on the lagoon floor and associated with gas seepages (average size diameter 0.97 ± 0.19 m and density from 54 to 242 units per 50 m2). In the NB three types of shallow gas features were found in the seismic profile, namely Acoustic Blanking, Turbidity Pinnacles and Intra-sedimentary plumes. The depth varied from the surface to 12.10 ms (around 18.15 m). In both environments, the gas is escaping from the sediment into the water column. The Pockmarks in the CL and the Acoustic Plume features and sediment rich in total sulfur in the NB validate these findings. Resumo Este artigo apresenta a distribuição espacial das estruturas de gás raso e as classifica com base em dois conjuntos de dados de registros sísmicos diferentes com o CHIRP, um na Lagoa da Conceição (CL) e o outro na Baía Norte (NB), ambos na Ilha de Santa Catarina, sul do Brasil. Os dados de sonar de varredura lateral da CL foram usados para facilitar a interpretação. Os dados sísmicos de subsuperfície (SB) foram processados e interpretados por meio do software SeisPrho e os dados obtidos com o sonar de varredura lateral (SSS), pelo software SonarWiz5. A medida espacial foi realizada por intermédio de GIS. As estruturas de gás raso foram definidas de acordo com as formas apresentadas nos registros sísmicos (eco-caráter). Na CL, as acumulações rasas de gás foram encontradas sob a forma de escapes nas exsudações e feições apresentando estruturas de gás superficial, entre a superfície e 8,20 ms (cerca de 12,3 m). Estas acumulações de gás foram encontradas na forma de Cobertura Acústica com Plumas Acústicas associadas, além de Sombra Negra. As pockmarks foram observadas no fundo da lagoa, ligadas aos escapes de gás (diâmetro médio de 0,97 ± 0,19 m e densidade de 54 a 242 unidades por 50 m2). Na NB observou-se três tipos de estruturas de gás raso no perfil sísmico, ou seja, de Cobertura Acústica, Pináculos de Turbidez e Plumas Intrssedimentares. A profundidade variou da superfície até 12,10 ms (cerca de 18,15 m). Em ambos os ambientes, o gás é expelido a partir do sedimento para a coluna de água. As pockmarks na CL e na NB, as feições de pluma acústica e os sedimentos ricos em enxofre total validam essa evidência.

Clastic, depositional strandplain systems have the potential to record changes in the primary drivers of coastal evolution: climate, sea-level, and the frequency of major meteorological and oceanographic events. This study seeks to use one such record from a southern Brazilian strandplain to highlight the potentially-complex nature of coastal sedimentological response to small changes in these drivers. Following a 2 to 4 m highstand at ca 5·8 ka in southern Brazil, falling sea-level reworked shelf sediment onshore, forcing coastal progradation, smoothing the irregular coastline and forming the 5 km wide Pinheira Strandplain, composed of ca 500 successive beach and dune ridges. Sediment cores, grab samples and >11 km of ground-penetrating radar profiles reveal that the strandplain sequence is composed of well-sorted, fine to very-fine quartz sand. Since the mid-Holocene highstand, the shoreline prograded at a rate of ca 1 to 2 m yr−1 through the deposition of a 4 to 6 m thick shoreface unit; a 1 to 3 m thick foreshore unit containing ubiquitous ridge and runnel facies; and an uppermost beach and foredune unit. However, the discovery of a linear, 100 m wide barrier ridge with associated washover units, a 3 to 4 m deep lagoon and 250 m wide tidal inlet within the strandplain sequence reveals a period of shoreline transgression at 3·3 to 2·8 ka during the otherwise regressive developmental history of the plain. The protected nature of Pinheira largely buffered it from changes in precipitation patterns, wave energy and fluvial sediment supply during the time of its formation. However, multiple lines of evidence indicate that a change in the rate of relative sea-level fall, probably due to either steric or ice-volume effects, may have affected this coastline. Thus, whereas these other potential drivers cannot be fully discounted, this study provides insights into the complexity of decadal-scale to millennial-scale coastal response to likely variability in sea-level change rates.

Este trabalho apresenta resultados da classificação morfodinâmica de praias de enseada do Estado de Santa Catarina (158 praias, do Cabo de Santa Marta à Ilha de São Francisco do Sul) e do Litoral Norte do Estado de São Paulo (133 praias, da Baía de Santos à Ubatuba), realizada indiretamente através de interpretação de imagens aéreas. Para isso foram construídos mosaicos georeferenciados com imagens do satélite QuickBird2 (para o Estado de Santa Catarina) e com fotografias aéreas verticais (para o Litoral Norte do Estado de São Paulo). Nas imagens foram analisadas a extensão das zonas de surfe e de espraiamento, presença de bancos, correntes de retorno e cúspides. Praias dissipativas apresentaram zonas de surfe e espraiamento extensas (> 100 m) e presença de sistemas de bancos múltiplos. Nas praias intermediárias foi observada uma extensão moderada das zonas de surfe (até 100 m) e espraiamento (até 10 m), além da presença de bancos rítmicos, correntes de retorno e cúspides. Já nas praias refletivas foi observada a ausência de zona de surfe (com a quebra de ondas ocorrendo na face da praia), zona de espraiamento estreita (< 10 m) e presença de cúspides. No Estado de Santa Catarina foi observado o domínio de praias refletivas. Essas praias dominam as regiões abrigadas, mas também ocorrem em locais expostos e com sedimento grosso. Seu domínio ocorre associado às baías Norte e Sul de Florianópolis, além da região da Costa Brava (da praia de Mata Camboriú à de Taquaras/Taquarinhas), que é exposta a ondas de maior energia. Praias intermediárias e dissipativas ocorrem predominantemente em regiões expostas. No Litoral Norte do Estado de São Paulo houve um equilíbrio entre praias refletivas e dissipativas. As praias refletivas tendem a dominar as regiões abrigadas (e.g. Canal de São Sebastião), mas o tamanho do sedimento disponível parece ser mais importante na determinação do estado morfodinâmico das praias protegidas, uma vez que também ocorrem praias dissipativas nesses locais. As praias intermediárias apresentam-se sempre em locais expostos. Observou-se a coincidência de mais de 70% da interpretação das imagens das praias do Estado de Santa Catarina e do Litoral Norte do Estado de São Paulo com dados de campo disponíveis na literatura. Conclui-se assim que a interpretação de imagens aéreas é um excelente método para determinar indiretamente o estado morfodinâmico de praias de enseada, desde que se tenha boas imagens e um interprete treinado e com experiência.

Inlet stabilization is a common practice in Brazil, as it is worldwide. In this paper we present results of the analysis of the stabilization practices of the Camacho Inlet, located in Santa Catarina State, southern Brazil. This inlet is maintained intermittently, in accordance with a regime designed to benefit both local fishermen and rice farmers. Fishermen require this inlet to be open as a navigation channel during the fishing season; rice farmers needs it closed during the irrigation period to allow the pumping of fresh water from the Congonhas River which drains into the Camacho’s backbarrier lagoon. An additional complication arises from the tendency of this inlet to close naturally due to infilling by dune migration. Aerial images spanning a 65 year time period (1938–2003) were analyzed, demonstrating the variability in the inlet’s width between 0 (closed) and 360 m. The analysis of inlet stability and user needs indicate that an appropriate solution is the implementation of an annual inlet dredging program in the austral autumn. This would allow for the inlet to remain open from May to September and then close naturally for the rest of the year, providing for a backbarrier fresh water reservoir during the irrigation period.

This paper presents a comprehensive review on the interaction between hydrodynamic processes, beach morphology and sedimentology at large scale coastal behaviour along the coastline of Santa Catarina, between Laguna and Sao Francisco Island, a microtidal east coast swell environment with headland and bay geomorphologies. The parabolic bay shape equation has proven to be a convenient and practical tool for studying the stability of the headland-bay beaches, tombolos, and salients in Santa Catarina. The beaches exhibit different patterns of sediment removal as a function of the degree of beach curvature. In highly curved beaches, there is a well-developed shadow zone and a range of morphodynamic conditions, from a sheltered low-energy beach adjacent to the downdrift headland to a high-energy exposed beach on the straight end of the headland-bay beach. The less curved beaches instead, tend to show more uniform behaviour since they are directly exposed to incident waves. There is no obvious relationship between average wave height and mean grain size, showing the importance of sediment source to characterize the sedimentary distribution patterns in the study area. The analysis of beaches showed that beach morphodynamics and sequence profiles for a bay–headland coast in a microtidal east coast environment is a function of geological inheritance (e.g., distance between headlands and orientation, nearshore and inner shelf morphology, coastal plain morphology, and sediment source), and hydrodynamic factors (wave conditions, oceanic wave exposure and relative tidal range).

This paper presents MEPBAY and SMC software tools that allow comprehending and solving problems in headland-bay beach through a parabolic model. These tools can be employed as coastal engineering design tools (including nourishment designs) and also for academic purposes. They are oriented to different end-users, including coastal technicians, scientists and undergraduates and as coastal engineering design tools, they can be applied to different operational levels (pre-design and design). The aim of the paper is to present design guidelines, the capabilities of the tools, their potential use and applications. Both tools were applied to analyze San Lorenzo Beach and demonstrate their ability at different project levels.

This paper aims to quantify the uncertainty in the application of the Parabolic Bay Shape Equation (PBSE) for a bay in static equilibrium. By means of expert elicitation, a database was generated consisting of the position of the control points that determine the Static Equilibrium Planform (SEP). The elicitation consisted of two parts. In Part 1, 22 expert volunteers were asked to place the three control points that determine the SEP on a vertical aerial photograph of Taquaras–Taquarinhas Bay, a morphologically stable bay in the south of Brazil, approximately 1800 m in width and with an indentation of 750 m. The distribution of the location of the SEP along four evenly spaced (200 m) profiles in the southern part of the bay was determined. The overall bias of the location of the SEP calculated over the four profiles was in the order of 41 m (landward) and the average standard deviation was 116 m. These parameters increased when moving alongshore toward the curved section of the bay. This means that the uncertainty in the application of the PBSE is dependent on the particular point of interest along the bay. In Part 2 of the elicitation, 30 volunteers participated. This time the consequence of the placement of the control points (the corresponding SEP) was visible. Comparing the results from Parts 1 and 2, it was observed that when volunteers were directly confronted with the result of the placement of the control points (a plotted SEP) a much smaller variation in the position of the SEP occurred. This implies that when feedback on the result is provided the PBSE is a more robust method.

This paper attempts to highlight issues that are relevant in the application of the Parabolic Bay Shape Equation (PBSE) to a non-equilibrium bay. For this case, the bay of Imbituba in southern Brazil was chosen. The construction of a breakwater to shelter the port of Imbituba in the south of the bay was accompanied by an increase in sedimentation to the port area from an eroding downdrift beach. Superimposed plots of the coastline of the Bay of Imbituba from different years confirm a general trend of accretion of the southern part of the bay accompanied with a retreat of the coastline in the northern part. After the application of the PBSE it became clear that the breakwater caused a change in the equilibrium state of the bay. Between 1947 and 2001 the Bay of Imbituba has changed from a dynamic equilibrium to a natural beach reshaping or self-reshaping. The tendency of the sedimentation of the southern part of the bay can be explained by the SEP associated with the new updrift diffraction point (tip of the breakwater): The seaward position of the SEP predicts a need for additional sediment in order to achieve a stable plan form.

Estuarine hydrodynamics is a key factor in the definition of the filtering capacity of an estuary and results from the interaction of the processes that control the inlet morphodynamics and those that are acting in the mixing of the water in the estuary. The hydrodynamics and suspended sediment transport in the Camboriú estuary were assessed by two field campaigns conducted in 1998 that covered both neap and spring tide conditions. The period measured represents the estuarine hydrodynamics and sediment transport prior to the construction of the jetty in 2003 and provides important background information for the Camboriú estuary. Each field campaign covered two complete tidal cycles with hourly measurements of currents, salinity, suspended sediment concentration and water level. Results show that the Camboriú estuary is partially mixed with the vertical structure varying as a function of the tidal range and tidal phase. The dynamic estuarine structure can be balanced between the stabilizing effects generated by the vertical density gradient, which produces buoyancy and stratification flows, and the turbulent effects generated by the vertical velocity gradient that generates vertical mixing. The main sediment source for the water column are the bottom sediments, periodically resuspended by the tidal currents. The advective salt and suspended sediment transport was different between neap and spring tides, being more complex at spring tide. The river discharge term was important under both tidal conditions. The tidal correlation term was also important, being dominant in the suspended sediment transport during the spring tide. The gravitational circulation and Stokes drift played a secondary role in the estuarine transport processes.As trocas de água e materiais através das desembocaduras de estuários são de difícil quantificação e são de fundamental importância para o entendimento do funcionamento de estuários e da zona costeira. A hidrodinâmica e transporte de sedimentos em suspensão no estuário do rio Camboriú foram estudados através da realização de duas campanhas de campo em 1998 cobrindo as condições de quadratura e sizígia. O período do levantamento foi anterior à obra de construção do molhe em 2003 que alterou a morfologia da desembocadura, fornecendo assim importantes informações base sobre o sistema. Cada experimento cobriu dois ciclos de maré com medições horárias de correntes, salinidade, concentrações de sedimentos em suspensão e nível de água. Os resultados mostram que o estuário é parcialmente misturado com estrutura vertical variando em função da amplitude e fase da maré. A estrutura dinâmica do estuário é balanceada entre os efeitos estabilizadores gerados pelo gradiente vertical de densidade, que permite produzir fluxo de empuxo e estratificação, e os efeitos turbulentos gerados pelo gradiente vertical de velocidade, que gera mistura vertical. A principal fonte de sedimentos para a coluna de água são os sedimentos de fundo, periodicamente resuspendidos pelas correntes de maré. O transporte advectivo de sal e sedimentos em suspensão foi diferente entre condições de quadratura e sizígia, sendo mais complexo durante a sizígia. A circulação gravitacional e a deriva de Stokes apresentam um papel secundário nos processos de transporte estuarinos.

Sandy bay beach in static equilibrium is the only physiographic feature that could remain stable without sediment supply in a persistent swell environment anywhere around the world. With a continuing trend of erosion to sandy beaches worldwide, a conservative and practical hypothesis is not to consider the mobile dynamic wave parameters but to safeguard against a sandy beach under vanishing supply in the future. To achieve this, an empirical bay shape equation is strongly recommended as one of the best coastal management options. Combining with MEPBAY, software derived for implementing the static bay beach concept on a display unit, this empirical bay shape equation is readily applicable to verify the stability of numerous headland bay beaches in natural and man-made condition. It is also adequate for coastal managers to apply this empirical equation as a valuable tool to aid in the creation of headland bay beaches for shore protection, recreation, and coastal management before embarking on sophi...

The Santa Catarina coast is located in southern Brazil between 26° and 29.3°S. The coast trends south then southwest for about 430 km, and contains 922 km of open coast and bay shoreline, with 246 sandy beaches occupying 60 % of the shore. Based on geology and orientation the coast is divided into five coastal provinces, each of which contains a different suite of beach systems. The provinces and their beaches range for the highly embayed Penha to Baia Norte province which is dominated by short low energy reflective beaches, to the exposed high energy Cabo Santa Marta to Torres province which has long near continuous multi-barred dissipative beaches. This chapter reviews the provinces and their beach systems including spatial and temporal controls, as well as beach erosion, hazards and safety.

Beach nourishment on open ocean beaches not bounded by headlands or other structures suffers from high rates of lateral losses of fill volume as the nourished shoreline equilibrates with its surroundings. Estimates of lateral losses are essential for beach nourishment design, these predictions have been made in the last decade utilizing empirical formulations, one line models or lately, process-based coastal morphology models. Coastal morphology models are, however, complex and computationally intensive and in order to maintain a balance between model complexities, computational effort and processing capacity, schematization of model input (input reduction) is necessary. This paper is divided into two main sections. In the first section techniques of wave input reduction for morphological models are evaluated with focus on open ocean wave-dominated coasts. Subsequently, the optimized morphological model is applied to evaluate coastal engineering interventions aimed at reducing volume losses from the Delray Beach nourishment project. Wave input reduction is defined here as the process of reducing the full wave climate of a given coastal region to a set of representative wave-wind conditions, ‘running’ a model with these representative wave conditions in sequence for a smaller time period (i.e. a few tide cycles) and multiplying its effect on the morphology by a Morfac value, that is related to the frequency of occurrence of that wave condition in nature, or its weight in the overall wave climate. Five different techniques of wave input reduction were tested. Of all the methods of wave climate schematization tested the methods defined as ‘Energy Flux Method’ and ‘Opti Method’ showed best results in terms of representing accurately the sediment transport patterns of the study area. The tests conducted indicate that a number around 12 representative wave cases was enough to represent an annual wave climate compared to a very detailed wave climate used as benchmark. The optimized model was used to evaluate alternative engineering solutions to reduce volumetric losses from the beach nourishment project. Engineering solutions evaluated included a construction of a breakwater field, backfilling all dredge pits located offshore of the project site, construction of a groin field at the downdrift end of the project, and backfilling the deepest dredge pit. These engineering interventions caused a reduction in beach volume losses within the project limits with varying levels of effect on the downdrift beaches. Reduction of the volume loss from the project site is technically feasible and may be economically feasible pending further economic feasibility evaluation.