The morphodynamics of a swash bar was monitored over two tidal cycles during a storm event at Skallingen, Denmark. Higher water levels during the first tidal cycle forced waves to break either landward of, or at, the bar crest. The bar was unable to significantly alter the pattern of wave breaking over the foreshore slope, creating a potential for bar erosion through an offshore transport of sediment. In response, the bar became more symmetric in cross-section, and its height decreased. Lower water levels during the second tidal cycle forced waves to break on the seaward slope, causing the bar to rebuild and its crest to migrate onshore. The onshore migration of the swash bar occurred despite little change in the offshore wave height from one tidal cycle to the next and in conditions that are typically associated with offshore transport and bar migration. The results further illustrate a strong tidal dependency in which water depth relative to bar height is an important control on the morphodynamics of the swash bar, but in a manner that appears contrary to recent evidence from the subtidal zone.

Cospectra of velocity and concentration from collocated sensors during the second tidal cycle exhibited a strong infragravity signal, with sediment resuspension largely restricted to the onshore phase of the infragravity oscillations. Suspension during this phase was associated with the passage of individual surf bores and exhibited a depth-dependent phase lag with the velocity accelerations at the leading face of the wave. It is proposed that the primary role of the acceleration is to alter the amount of sediment suspended, with a net onshore transport accomplished by the skewness in the oscillatory velocity field. However, the onshore migration of the swash bar could only be explained by the gradient in the acceleration skewness, which was sufficiently coupled spatially with the morphology.

Divers in the 1980s discovered a large concentration of archaeological material on the seafloor off Kaulonia, a Greek colony on the Ionian coast of southern Italy. It has been proposed that a small hook-shaped cape, now submerged, was present off the site during settlement from about 700 to 389 BC. Since 1992, however, most of Kaulonia's seafloor sector has been buried by a thick (to 4 m) sand cover. This investigation resumes study of Kaulonia's margin by high-resolution seismic survey, analysis of sediment in cores and excavated sections buried along the coast, and petrologic examination of rock used for construction of a temple, the site's major structure. The sector, located in the tectonically active Calabrian arc, has been subject to considerable elevation rise of land onshore, and an equivalent rate of seafloor subsidence (∼1 mm/yr). A distinct Holocene sequence, composed of beachrock-type sandstone and fluvial-marine–transported conglomerate, in sediment sections landward of the beach can be traced seaward to depths of ∼7 m about 300 m from the present shoreline. Correlation of the sequence helps define changes of coastline position from before Greek settlement to the present. Rather than a generally progressive migration landward of the shoreline in response to relative sea-level rise, the coast has experienced more complex shifts (sea-to-land, land-to-sea, and return to land) due to up-and-down motion in the sector between the alluvial plain behind the beach and innermost shelf. By the mid-Holocene, the shoreline had advanced seaward, resulting in coastal emergence, and it did not return landward (resubmerging the margin) until after the site's abandonment; submergence was complete by late Roman time. We now recognize a broad arcuate headland, rather than a small hooked cape, seaward of the site ∼2500 years ago. Without a lagoon, sufficiently deep lake, or man-made port available for protected anchorage, vessels sailing to Kaulonia for trade were either beached or anchored close to shore and, perhaps seasonally, within the mouth of the Assi River. Composition of beachrock-type sandstone in Holocene sections on land is comparable to that offshore and also to sandstone used for temple base construction. Extensive sandstone exposures along this coast may have been one reason why Greeks selected the site for settlement.

Beach erosion, a problem along most sandy shores, can be caused by man-induced interventions to the coast or natural processes. Remediation of beach erosion (i.e., beach restoration) along eroding developed beachfronts is commonly practiced in the United States by periodic beach renourishment with or without coastal structures. Rates of erosion within beach fills generally vary greatly, and areas that erode faster than the nourishment average are commonly termed erosional hot spots (EHSs). Delray Beach, located on the southeast coast of Florida, was renourished for the fourth time on December of 1992 with about 914,000 m³ of sand dredged from offshore and placed along 2.7 km of beach. About 448,000 m³ of the fill had eroded away by 2001, about eight and a half years after initial construction. Two beach segments with erosion rates higher than the nourishment average were identified based on analysis of annual beach profile data. About 40% of the eroded volume accrued from one of these beach segments, a 600-m long EHS located on the downdrift end of the nourishment. We evaluated hypotheses to explain EHS development; these included the influence of nearshore features (reefs and borrows) on nearshore wave propagation, variability of grain size alongshore, and changes in shoreline orientation induced by the placement of fill. The nearshore reefs have little to negligible influence on the nearshore waves and are not the cause of the EHSs. Borrow areas significantly influence nearshore waves along the beach. Grain-size differences alongshore were also not the cause of increased erosion of EHS segments since grain sizes are not persistently finer where higher erosion is observed or vice versa. Change in shoreline orientation in the south end of the fill (EHS segment) causes an acceleration of the alongshore currents and an increase in sediment transport potential. Shoreline orientation effects appear to play a relatively more significant role in the development of the EHS in the south end of the fill than the other processes evaluated.

The Paranaguá Bay is located on the center-north littoral of the state of Paraná in the south of Brazil. Three natural channels give access to the Atlantic Ocean, denominated as North and Southeast (north of Mel island) and Galheta channel (south of the same island). The last one is the main access to the Paranaguá port, where maintenance dredging activities are necessary for navigation. This study aims to characterize the channel morphological variations from 1972 to 2000. It is our goal also to quantify the sedimentation rates for some critical sections of the channel and to understand the processes of sediment transport along the southern mouth of the bay. The wave front arrives preferentially from southeast, and the alongshore drift of the coastal sediments is toward the northeast. The alongshore sediment flux on the Paranaguá Bay mouth vicinities is characterized by two main fluxes: (1) on the external sector, one contours the terminal lobe of the ebb-tidal delta, deflecting the channel to the northeast. In spite of the rectification attempts, by dredging, channel deflection has persisted through the past decades. (2) On the inner sector, the sediment flux moves up the estuary, along the margin of the Pontal do Sul coastal village, being redirected by the ebb-tide currents proceeding from the Cotinga channel, to the Galheta channel. The tidal currents lose energy on the widest portion of the estuary, and the sediments are deposited there, forming an inner bank. Sedimentation rates calculated for the external sector varied between 19.3 and 229.2 × 10³ m³/mo, but a larger data set is necessary, for the confirmation of this pattern of channel shoaling.

Few observational techniques are capable of simultaneously mapping the shoreline and nearshore sand bars at high resolution and over large distances, especially during storms when waves are large and visibility is reduced. Proof-of-concept experiments were undertaken to test the feasibility of using X-band radar, mounted on a beach vehicle with dual-channel global positioning system (GPS), to rapidly map the swash and nearshore bars over several kilometers. Bar and Swash Imaging Radar (BASIR), a mobile system developed in collaboration with Imaging Science Research, was evaluated under varying wave heights and storm conditions through comparisons with bathymetric profiles and video along the North Carolina Outer Banks. The video, operated by Oregon State University Coastal Imaging Lab and the U.S. Army Corps of Engineers Field Research Facility in Duck, North Carolina, utilizes a similar technique of time averaging and multiple-image merging to map sand bars. Significant correlation and relatively low root-mean-square differences were found between the video and radar mosaics. Bar and swash imaging radar under-predicted the cross-shore distance of the inner bar relative to measured bathymetric profiles. Measurements collected during a storm with significant wave heights of 3.5 m compared very closely with the results collected 12 hours later when seas had fallen to 2 m. Results suggest BASIR may prove to be a robust observational technique for mapping the evolution of swash-defined shorelines and nearshore bars during storms. At present, limitations to BASIR include (1) alongshore mapping distance constrained by tide fluctuations and (2) the necessity of having wave heights substantial enough to dissipate over the mapped feature.

Technical information in support of integrated terrestrial and marine protected area conservation requires coastal zone base mapping that spans the land-sea interface. However, the coastal zone is currently served by two independent and nonoverlapping cartographic traditions—topographic maps and hydrographic charts. We discuss challenges towards harmonizing the information from these incompatible sources into a standardized base map capable of supporting future integrated terrestrial and marine conservation applications. We use an example from an archipelagic area off British Columbia, Canada, that aspires to mountaintop to sea-bottom conservation to highlight problems encountered when contemplating integrated topographic and hydrographic base mapping. Lack of a standardized representation of the coastline, confusing terminology, lack of high-density mapping of the coastal zone, and the inability to translate between various vertical datums are the most serious issues. Also, we review current solutions being developed toward improved base mapping for the land-sea interface.

Beach erosion has direct consequences for Hawaii's tourist-based economy, which depends on the attraction of beautiful sandy beaches. Within the last century, however, beaches on Oahu and Maui have been narrowed or completely lost, threatening tourism and construction development. In order for the counties and state of Hawaii to implement coastal regulations to prevent infrastructure damage, it is necessary to find a statistically valid methodology that accurately delineates annual erosion hazard rates specific to Hawaii. We compare the following erosion rate methods: end point rate (EPR), average of rates (AOR), minimum description length (MDL), jackknifing (JK), ordinary least squares (OLS), reweighted least squares (RLS), weighted least squares (WLS), reweighted weighted least squares (RWLS), least absolute deviation (LAD), and weighted least absolute deviation (WLAD). To evaluate these statistical methods, this study determines the predictive accuracy of various calculated erosion rates, including the effects of a priori knowledge of storms, using (1) temporally truncated data to forecast and hindcast known shorelines and (2) synthetic beach time series that contain noise. This study also introduces binning of adjacent transects to identify segments of a beach that have erosion rates that are indistinguishable. If major uncertainties of the shoreline methodology and storm shorelines are known, WLS, RWLS, and WLAD better reflect the data; if storm shorelines are not known, RWLS and WLAD are preferred. If both uncertainties and storm shorelines are not known, RLS and LAD are preferred; if storm shorelines are known, OLS, RLS, JK, and LAD are recommended. MDL and AOR produce the most variable results. Hindcasting results show that early twentieth century topographic surveys are valuable in change rate analyses. Binning adjacent transects improves the signal-to-noise ratio by increasing the number of data points.

In this paper, we review and analyze the cyclic morphodynamics and sand-bypassing processes at the Ameland Inlet, The Netherlands. The inlet is located between the islands of Terschelling and Ameland in the Dutch Wadden Sea. The bypassing rate and sand storage have a periodicity of 50 to 60 years in connection with the migration of the channels in the inlet and the transformation of the gorge between a one-channel and a two-channel system. These developments modulate the volumes of the shoal and bypassing bars and produce an attenuating sand wave toward the downdrift coast. An aggregate model is developed to describe the inlet morphology at this intermediate timescale. The model is based on a modified equilibrium-volume approach, which allows erosion and accretion of the shoal and bars to occur about their long-term equilibrium. The model results depict observed morphologic behaviors of the inlet and corroborate the measured modulation of the downdrift coastline. The simulation of the effect of the 1979 and 1980 sand mining operations in the ebb tidal delta reproduces the reported rapid recovery of the sandpits and illustrates the capabilities of the model as an inlet planning and management tool.

The purpose of this work is to identify and quantify those stretches in the Buenos Aires province that present different degrees of risk in view of the rise of the mean sea level and to determine its nature. The study focused on the Buenos Aires province coast because its variant geomorphology represents the different morphologies along the whole of the Argentinean coastline. The aim of this article is to study the response of two of the coastal vulnerability equations to the environmental diversity and to determine which one is more suitable to be applied to the rest of the country. On verifying the equations, CVI6 was found to be more appropriate for the analysis of coasts with different morphologies. Depending on the physical characteristics of each area, the consequences would include flooding and the loss of low lands in areas such as the Samborombón Bay, Bahía Blanca Estuary, and Anegada Bay, and the eroding of the beaches between Punta Rasa and Bahía Blanca.

Beach nourishment requires large volumes of sand from offshore and new sources are constantly sought for development. The sediment-starved continental shelf off the central-west coast of Florida has traditionally supplied beach-quality sediments from ebb-tidal shoals and nearshore sand sheets, but as these supplies dwindle, sand searches increasingly look farther offshore for resources. Widely spaced sediment ridges, interspersed by karstified limestone seafloor (hard grounds), offer potential as sand resources that can be exploited by dredging to renourish eroded beaches for shore protection. The sand ridges, late Holocene in age, are generally shoreface detached, sediment starved, and clustered in “ridge fields.” Six sediment ridge fields identified along 285 km of coast (Anclote, Sand Key, Sarasota, Manasota, Captiva, and Collier) contain about 1.4 billion cubic meters of sediments that are potentially available for dredging. Evaluation of these sediment sources, within the purview of the USMinval Code, requires the determination of resources, reserves, and level of certainty of assessment applied to a rating of resource potential. Present research is attempting to identify the overall resource potential with an eye toward eventually determining sand volumes in reserves, which will be much less than the total sand resource volume.

This study from summer 2002 describes the largely undisturbed vegetation cover of pioneer habitats on coastal dunes of the Świna Gate Barrier, west Polish coast. The aim of the study was to survey the morphology of the youngest undisturbed dunes on an accumulation coast and describe the different vegetation types. The influence from tourism in the main selected study area is rather low; however, increasing numbers of tourists potentially threaten the dunes. The result of the study is the map of habitats and graphs of species in each section of the dunes. Ecological indicator values were calculated for each section of the dunes, showing the changing ecological conditions for the different habitats. Each habitat has some typical species, which are sometimes completely restricted to this single habitat. Consequently, the value for conservation of these undisturbed complex dunal ecosystems with all habitat types is high.

Land subsidence due to consolidation of sediment was analyzed in the Yellow River delta, using lithological data of deposits, equations of soil mechanics, and empirical relations. Subsidence in an abandoned deltaic lobe largely results from the consolidation of deltaic clay layers accumulated in the prodelta, the bays, and marine clay layers underlying the delta. The prodelta and marine clay layers have a total thickness of approximately 14 m. In the areas where thick bay-clay layers accumulated on the prodelta-clay layers, the total thickness of the clay can reach 20 m. Calculations show that after 15-m-thick deltaic strata were deposited on the seabed, the total consolidation of the 14-m-thick clay layers is approximately 1.44 m and 1.52 m for the 20-m-thick clay layers. After the first 40 years, the rate of land subsidence resulting from consolidation of the 14-m-thick clay layers will decrease gradually to 0.005 m/y. For the 20-m-thick clay layers, it will take 57 years for the rate of subsidence to decrease to 0.005 m/y.

Remotely sensed images, maps, charts, and historical accounts document the evolution of the Lingayen Gulf bayhead plain in the northwestern Philippines. Beach ridges and relict channel patterns record delta progradation and switching that, together with meander belt migration, constructed the bayhead plain. The latest delta switching occurred after 1935, when the downstream portion of the Agno River, the largest river discharging into the bayhead, was artificially diverted to a more direct route. The shoreline retreated in the abandoned delta; in contrast, paired sets of beach ridges that diverge toward the new river mouth formed a cuspate delta. In the more landward portions of the coastal plain, similar but older pairs of wedge-shaped beach ridge sets occur between more continuous to parallel sets that also truncate their apical ends. The pair of wedge-shaped sets was used to map paleodelta lobes; the continuous-parallel sets record transgressive events. Within 7 kilometers of the bayhead plain, at least 15 paleodelta lobes were alternately, successively, or simultaneously built by three river systems. These paleodeltas formed during the sea level fall from 2.4 ka to the present. Before this, westward tilting because of movements along the two faults that bound the alluvial plain and switching of the main distributary channel of the Agno alluvial fan caused the lower Agno River to migrate episodically to the southwest. Continued channel avulsions in the alluvial fan changed the sediment loads of the multiple river pathways created by meander belt migration, leading to delta switching downstream. Contemporaneous 220-year recurrences of delta switching and high-magnitude Philippine Fault earthquakes indicate tectonic control of the bayhead plain evolution.

A set of quantitative parameters is derived for the morphological characterization of estuaries. This is the first part of a long-term project aiming at the ecological characterization of tidal environments, which should provide practical tools for the management of such systems. The parameters apply to the macroscale, that is, the scale of the estuarine cross-section, including channels and adjacent intertidal areas. They are derived from recent theoretical models for estuarine morphology, as well as data from the tide-dominated Scheldt estuary. The set of parameters is believed to be universally representative, although this needs to be supported by further research, including data from other estuaries. The analysis suggests that morphodynamic equilibria do not form a continuum but manifest themselves as discrete steps. For each step, there is a straightforward relation between the extension of the intertidal areas and the other parameters. For the Scheldt estuary, large width-to-depth changes are necessary to jump from one equilibrium state to the other.

The seasonal variations of water quality parameters as nitrite plus nitrate (NO⁻;_x), total phosphate (PO³⁻₄), chlorophyll a (chl a), and dissolved oxygen (DO) are analyzed across the Croatan-Roanoke-Albemarle-Pamlico-Core Sounds estuarine system (CAPES). Overall, several patterns are observed: The Chowan-Roanoke-Albemarle system is generally phosphorous limiting for phytoplankton growth, whereas both the Tar-Pamlico and the Neuse Rivers are generally nitrogen limiting. The largest PO³⁻₄ gradients exist in the upstream portion of the Albemarle Sound, and the largest NO⁻_x gradients exist in the lower Neuse and the Tar-Pamlico Rivers. Dissolved oxygen appears to have the strongest seasonal signal among the water quality variables, with highest DO values observed during winter (within the CAPES and in the nearshore area) or spring (in the continental shelf and deeper ocean) and lowest during summer. Chlorophyll a concentrations are highest during spring (within the CAPES) or winter (offshore). In contrast, the NO_x⁻ and PO³⁻₄ concentrations in both the Tar-Pamlico and Neuse River estuaries are usually higher during the second half of the year. The time differences of the peak nutrient and chl a concentrations suggest that highest algal growth rate (and hence nutrient uptake rate) occurs during spring, and the consumed nutrients are released to the water column through a nutrient recycling method later in the year.

A coupled three-dimensional hydrodynamic water quality model is then applied to the entire system. The general model setup and parameter derivation of the model is presented here. The basic observed water quality characteristics such as the nutrient limiting pattern and the spatial gradients across the system are reproduced in the model. The model results also suggest that nutrient fluxes, generated from the diagenesis of deposited organic matter and released from the sediment bed, could be an important mechanism for nutrient recycling in the region.

A study was conducted on the south Texas Gulf Coast to evaluate color-infrared (CIR) aerial photography and CIR true digital imagery combined with unsupervised image analysis techniques to distinguish and map black mangrove [Avicennia germinans (L.) L.] populations. Accuracy assessments performed on computer-classified maps of photographic and digital images of the same study site had both producer's and user's accuracies of 100% for black mangrove. An accuracy assessment performed on a computer-classified map of a digital image only of a second study site had a producer's accuracy of 78.6% and a user's accuracy of 100%. These results indicate that CIR photography and digital imagery combined with image analysis techniques can be used successfully to distinguish and quantify the extent of black mangrove along the south Texas Gulf Coast.

We differentiated the sandy coast of South China into three basic types of coastal geomorphology: cape-bay coast, barrier-lagoon coast, and straightened coast. After analysis on regional variations of the dynamic environment along the modern coast of South China and comprehensive comparisons among on-the-spot observational data in different seasons from different foreshore profiles of the sandy coast situated on different geographic coastal sections, the morphodynamic characteristics of the sandy beaches along the coast of South China were explored. The tectonic movements and sea level changes occurring during the regional geologic historical processes lay down a basis for the development of large-scale sandy coastal geomorphology. After the postglacial, sea level was relatively stable. Under recent coastal dynamic conditions, the scouring-silting adjustment made by the actions of supply, migration, and accumulation of the sandy beach sediments made decisive effects on the state of the beach face. Among them, the wave-tide index (K value) is an important indicator that reflects these changes. The K values of sandy beaches along the coasts of South China are generally more than 1. Most of the sandy beaches are predominated by wave-dominated geomorphology, with a rather great beach face gradient. There correlation between the K value and seasonal deformation degree of the sandy beach is positive. The grain size of the beach face sediment is closely related to the K value and also is affected to a smaller extent by the seasonal changes of wind wave and the geographic distribution of the various shorelines.

Storm overwash is a critical issue in coastal management efforts to mitigate damage to infrastructure. This paper contributes to those efforts by documenting the findings of a field survey at the Perdido Key, Florida, section of Gulf Islands National Seashore following the landfall of tropical cyclone Isidore in September 2002. The poststorm survey of overwash sites detected scouring along the northern edge of an access road that faced away from the Gulf of Mexico and the oncoming storm surge. Most sites experienced removal of minor amounts of sand and roadbed material, which left the edge of the overlying asphalt road surface unsupported. However, more severe scouring at one site caused the overlying asphalt road surface to fracture and collapse. An extreme example of this process was observed following the landfall of Hurricane Opal at Pensacola Beach, Florida, in 1995. The scouring process and its effects were consistent with a process recognized in fluvial systems as knickpoint development. Related scouring processes known as hydraulic jump and dam overtopping are also discussed. Coastal management options for mitigating this problem include reducing overwash and increasing resistance to scour. Methods to protect dams from overtopping offer potential solutions to this problem. An alternative solution is proposed that would offer protection against minor overwash events; however, it is unlikely that any of the methods discussed herein would be highly effective against an extreme event like Hurricane Opal.

Schinus terebinthifolius Raddi (Schinus) is one of the most widely found woody exotic species in South Florida. This exotic is distributed across environments with different hydrologic regimes, from upland pine forests to the edges of sawgrass marshes and into saline mangrove forests. To determine if this invasive exotic had different physiological attributes compared to native species in a coastal habitat, we measured predawn xylem water potentials (Ψ), oxygen stable isotope signatures (δ¹⁸O), and sodium (Na ) and potassium (K ) contents of sap water from plants within: (1) a transition zone (between a mangrove forest and upland pineland) and (2) an upland pineland in Southwest Florida. Under dynamic salinity and hydrologic conditions, Ψ of Schinus appeared less subject to fluctuations caused by seasonality when compared with native species. Although stem water δ¹⁸O values could not be used to distinguish the depth of Schinus and native species' water uptake in the transition zone, Ψ and sap Na /K patterns showed that Schinus was less of a salt excluder relative to the native upland species during the dry season. This exotic also exhibited Na /K ratios similar to the mangrove species, indicating some salinity tolerance. In the upland pineland, Schinus water uptake patterns were not significantly different from those of native species. Differences between Schinus and native upland species, however, may provide this exotic an advantage over native species within mangrove transition zones.

The structure and function of intertidal communities are intimately linked with hydrologic regime, which itself is defined by elevation gradients relative to sea level. Water surfaces have long been used as a reference plane for determining topographic profiles of the underlying ground surface. Although relatively straightforward in static systems such as lakes or ponds, this method is more complicated in the intertidal zone where the water surface is in vertical motion. Here we evaluate a technique using water marks to indicate maximum tide heights from which ground elevations relative to a tidal datum can be calculated. Comparisons of data using this technique to optical-leveling surveys in several salt marshes of Connecticut and Massachusetts showed that the water surface conformed to a horizontal plane at high, slack tide and that watermarks could be used as a reliable reference plane for determining ground elevations from flooding depth.

On the basis of recent advances in the formulations of atmospheric stability and sea-surface roughness, a parameterization of overwater friction velocity (u_*) is derived. It is shown that during hurricane conditions, u_* can be obtained from U₁₀, the wind speed at 10 m height. Verifications of the proposed equation against the correspondent data sets based on boundary-layer theories from three hurricanes are successful for operational applications.