Building on an earlier study of global trends in sandy beach macrofauna communities, based on published surveys of 161 beaches, we examine trends in biological factors, especially mean individual body size and community density. Mean individual body size decreases across the gradient from reflective to dissipative beaches, although this decrease cannot be explained by any single factor. Density increases across this gradient so that dissipative beaches support densities of macrofauna orders of magnitude above those recorded on reflective beaches, implying that the potential for competition and other biological interactions is much greater in dissipative systems. Some latitudinal variation occurs in mean individual body size, but there are minimal latitudinal effects on density. Progressing from reflective to dissipative beaches, species richness increases much faster than predicted by the usual species area relationship, indicating that changes in the nature of the beach over this gradient, rather than simple area effects, enable many more species to colonise dissipative beaches. We concluded that the change in macrofauna communities across this gradient of beach types is not simply a response to increasing area (or beach width), but rather that an increasingly benign environment allows more species, greater densities, and more small and delicate forms to occur on dissipative beaches.

In an effort to identify the potential effects of beach replenishment projects on waterbird and shorebird communities, avian abundance, species richness, and behavior were monitored at three transects before and after beach replenishment. The length of the study was 2 years with weekly surveys for most of the year. Data were analyzed with a Before/After Control Impact Pairs (BACIP) design, which incorporated spatial and temporal data from a control beach and replenished beaches into one analysis. No significant changes in mean waterbird and shorebird abundance were detected after replenishment, although the data do suggest that habitat use by waterbirds might have increased at replenished beaches. Of the individual waterbird and shorebird species examined, only Laughing Gulls and Black-bellied Plovers exhibited a significant change in abundance after replenishment, with these species exhibiting an increase and a decrease, respectively. Postreplenishment changes in waterbird and shorebird species richness were not consistent. Waterbird feeding activity declined significantly after replenishment, but, overall, there was no strong evidence that shorebird and waterbird feeding activity were altered by replenishment. Despite the BACIP design, high variability was common for most parameters. Recommendations for future bird monitoring projects include the use of multiple control sites and scheduling surveys to reduce all potential sources of variability.

Field measurements of tidal current velocities are used to infer sediment transport characteristics in the lower section of a large, tidally dominated estuarine system at Whangarei Harbour, New Zealand. Recent (2002) developments at the harbour entrance included a 32.6 ha intertidal reclamation and a 31.8 ha dredged turning basin. Residual distance vectors indicate that the postdevelopment, large-scale pattern of sediment transport dynamics remains consistent. Minor, localised modification of transport potentials has been observed immediately adjacent to the developments, however. These modifications include a slight realignment of current flows near the reclamation wall and some leakage from a previously identified transport loop near the dredged basin. The potential for scour is identified along the eastern margin of the dredged basin, which could act to remove material moving downslope into the basin from its western edge. These data are consistent with numerical model results that predicted minimal consequences resulting from the developments. Lower harbour sediment dynamics are consistent with established patterns for tide-dominated inlets, with separation of the channel into areas of ebb and flood dominance, and typical transport patterns over the flood tidal delta. Broad-scale inlet geomorphology has been maintained, which is consistent with other dredged tide-dominated inlets.

The paper presents the coastal vulnerability index (CVI) for the estimation of vulnerability of the coastal region of Mangalore coast, India, from Talapady to Surathkal. The CVI is an indication of the relative vulnerability of the various segments of the Mangalore coast to coastal erosion hazards. The following variables are used in the estimation of CVI, which is used to rank the vulnerability of the coastal regions: geomorphology, regional coastal slope, shoreline change rates, and population. The rankings for each variable were combined and an index value calculated for 1′ × 1′ grid cells covering the study area.

Field measurements were used to investigate circulation, mixing processes, and variations in temperature and salinity in the coastal boundary layer off Perth, Western Australia. This region is characterized by a low amplitude diurnal tidal regime, a strong southwesterly summer sea breeze, and a topography dominated by submerged barrier reefs. Subinertial current dynamics were analyzed using a simplified depth-averaged alongshore momentum equation. Offshore of the reefs, the results showed a balance between wind stress, alongshore pressure gradient, and bottom friction and acceleration forces. The alongshore pressure gradient contributed to accelerating the water body, but wind was the dominant driving force for a majority of the time. Onshore of the reefs (lagoonal waters), the alongshore dynamic balance was mainly between wind stress and bottom friction. The temperature variability in Perth coastal waters was in agreement with the seasonal variations in the net air–sea heat flux. The exchange rates between lagoonal waters in the area and the adjacent shelf waters were estimated, and the results showed an estimated flushing time of 4 to 13 days for the lagoonal waters. The seasonal variations of salinity in the area were dominated by changes in the salinity of the offshore waters and local discharge of groundwater. The vertical structure of the nearshore water was found to be dominated by wind mixing. In summer, solar heating in the morning stratified the water column, the sea breeze mixed the water column in the afternoon, and convective cooling at night sustained this mixing until the early morning; in winter the water column generally remained mixed throughout the day.

The seasonal dynamics of phytoplankton chlorophyll and nutrients were studied between August 1997 and March 1999 along a cross-shelf section of the inner coastal of Paraná State, southern Brazil. Vertical thermohaline stratifications in the rainy summer alternated with winter homogeneities. Nitrate-N varied from 0.17 to 1.13 µM, nitrite-N from 0.04 to 1.10 µM, phosphate-P from 0.37 to 0.73 µM, and silicate-Si from 2.5 to 10.2 µM, all presenting maximum concentrations at the bottom layers at the outer stations. Chlorophyll concentrations varied from <0.02 to 10.8 µg·L⁻¹ throughout the study period, with maxima at subsurface and bottom layers depending on the season. Seasonal differences in the distributional patterns of nutrients and chlorophyll were caused by two main wind-driven physical processes: (i) onshore intrusions of South Atlantic Central Waters and (ii) remote continental runoff from La Plata River. These were considered the main sources of new nutrients in summer and winter periods, respectively. Phytoplankton biomass (indicated by chlorophyll concentrations) tends to accumulate at subsurface layers, representing the primary source of organic matter for pelagic and benthic habitats in the inner shelf off Paraná State.

The Bragg resonant reflection of water waves propagating over a sinusoidally varying topography is investigated numerically by using a couple of ordinary differential equations derived from the Boussinesq equations. Derived governing equations are integrated with a fourth-order Runge-Kutta method. Applied topographies are focused on the shallow-water environment and intermediate depth zone, where the Boussinesq equations are suitable for describing behaviors of waves. Incident waves are random waves, which can be frequently observed in shallow-water regions. Optional shapes of incident waves are approximated with the Fourier decomposition. The Bragg reflection of random waves is simulated by using the TEXEL storm, MARSEN, ARSLOE (TMA) shallow-water spectrum in this study. Evolution and reflection of random waves are largely influenced by nonlinearity.

This paper discusses the problems of sedimentation in the entrance to a fishery harbour and its impact on the morphology of a sandy, very exposed coastline. An improved layout of the main breakwaters has been developed. The results obtained from testing the new layout in a morphological modelling complex are discussed. The new layout is expected to lead to improved bypass, decreased sedimentation and coastal impact, and a greater natural depth at the entrance, and to provide safer navigation conditions. The reliability of the modelling results was established through a comprehensive calibration process in which historical morphological development scenarios were successfully simulated. The recommended layout has been constructed and was inaugurated in December 2004. The performance of the new layout seems promising with respect to maintaining the required navigation depth in front of the entrance. However, because of the short operation time since the opening, sufficient quantitative data on maintenance dredging in the outer harbour is presently not available.

Habitat choice and interactions of foraging shorebirds and gulls were studied at a migratory stopover in Delaware Bay, New Jersey. Foraging, vigilance, aggressive behavior, and habitat choice of shorebirds were affected by the presence of gulls. There were significant differences in the time each species devoted to actively feeding; knots spent significantly less time foraging than did the other species. Birds congregated in the habitats where their foraging rates were the highest. When turnstones and laughing gulls fed in larger conspecific flocks, they had higher foraging times. Red knots were most aggressive toward laughing gulls, turnstones were most aggressive toward herring gulls, sanderlings were most aggressive toward turnstones, and semipalmated sandpipers were most aggressive toward knots.

There were significant differences in habitat use: 1) Gulls and turnstones were more abundant along the tide line, 2) turnstones were more abundant on the upper beach, 3) semipalmated sandpipers and turnstones were more abundant on sandbars, 4) only gulls fed on the beach mud, and 5) laughing gulls and semipalmated sandpipers were more common along creeks than were the other species.

Within 5 minutes of a human disturbance, gulls returned to predisturbance levels, while the shorebirds did not. Shorebirds responded most strongly to the presence of dogs than to other disturbances and did not return to beaches following a disturbance by a dog. These observations suggest that there may be some competition for foraging space among foraging species, especially between the shorebirds and the larger gulls, that human disturbance affects shore-birds more strongly than gulls, and that shorebirds and gulls use the habitats differently. The data can be used to manage human disturbance and to protect habitats where the shorebirds have the highest foraging rates, but the least exposure to gulls.

Waves and currents recorded off Chavara, southwest coast of India, over a period of 2 years are used to understand the wave-current regime of this monsoon dominated coast. The waves during monsoon are characterised by higher heights, shorter periods, and are confined to westerly directions. The wave characteristics indicate nearby generation. The premonsoon and postmonsoon waves are characterised by lower heights and higher periods with the direction being more southerly. Waves arrive from a wider range of generating areas during the fair weather periods, particularly during the premonsoon months. The wave heights exhibit yearly variations, but the periods and directions remain relatively constant. Like the waves, the currents also show seasonal changes with stronger currents during monsoon and weaker currents during fair weather. The alongshore components of the currents are mostly much stronger than the cross-shore flows and the pattern is mostly diurnal although a semidiurnal signal is also readily apparent, the latter associated with tidal currents. The diurnal activity is mostly wind-induced. In the monsoon season, the dominant direction is southerly to southwesterly, whereas during the premonsoon and postmonsoon it varies between northwest and southeast. Notable deviations to the generally understood pattern of southerly currents during monsoon and northerly currents during fair weather are observed. This could be attributed to the reported occurrence of a cyclonic eddy during monsoon and anticyclonic eddy during fair weather in the Lakshadweep Sea.

Wind-tunnel experiments were conducted to investigate the effects of vegetation, in particular beach grass, on blown sand in terms of elevation changes of a mobile sand bed and distributions of mean wind velocity for various vegetation canopies. For flexible vegetation layer displacement amplitude of vegetation leaf sway was also measured. The results indicate that a vegetation canopy with low height, high density, and vegetation flexibility is effective in reducing the sand-transport rate. Within and above a canopy of flexible vegetation, the vibrations of leaves increases the air turbulence, which creates a complex interaction between the mean wind velocity and the air turbulence, and thereby reduces the wind velocity in the vegetation area; consequently, the sand-transport rate decreases.

I treat the reflectance of light from coastal ocean water in terms of diffused volume scattering phase function P(θ) derived from successive products of the normalized volume scattering function β(θ). My results show that the wavelength dependence for backscattering in a multiple scattering process is directly proportional to the angle-independent dimensionless source function b/a, which is the ratio of the total volume scattering coefficient b and the total volume absorption coefficient a. I use this result to produce a statistical formula for remote sensing reflectance (R_rs). The statistical formula shows good agreement with experimental data, and—unlike the standard oceanographic expressions for R_rs given in terms of b_b/(a + b_b), where b_b is the volume backscattering coefficient—the statistical relationship for R_rs accounts for the effects of photon turnaround and reduces to the expected asymptotic limits for diffuse reflectance when a → 0 but b_b remains finite and when b_b → 0 but a and b remain finite.

Anthropogenic management of dynamic ecosystems has led to decline of species dependent on processes that maintain suitable habitat, particularly on barrier islands. By evaluating environmental variables over large geographic areas, remote-sensing data and geographic information systems (GIS) hold increasing promise for management of these unique habitats and their species associates. We used light detection and ranging (LIDAR) data to extract habitat variables for Amaranthus pumilus, a federally threatened flowering annual of the Atlantic barrier islands. We asked: (1) can habitat variables for A. pumilus be extracted from remote-sensing data, and (2) can these variables be used to model suitable habitat?

We extracted topographic habitat variables for naturally occurring plants and evaluated habitat using multiple statistical techniques and other published model performance measures. We found that elevation was the most limiting topographic variable controlling the occurrence of Amaranthus pumilus. The most occurrences fell with in a 1.23 m range relative to local mean high water. Additionally, we used digital imagery collected concurrently with the LIDAR data to assess the role of vegetation cover in A. pumilus distribution. The occurrence of seabeach amaranth in previous years also was factored into the models. The models performed well, predicting 46%–100% of the plant occurrences using as little as 2% of the habitat.

Amaranthus pumilus can potentially serve as a conservation “umbrella” for coastal biodiversity. The methods presented here for identification of A. pumilus habitat, using GIS and model construction of potential habitat, can be applied to other species of concern, including nesting shorebirds and sea turtles.

Damages during extreme wind events highlight the weaknesses inherent in coastal residential building construction and underscore the need for improving the structural performance of typical residential buildings. Also, there is a tremendous concern for the existing stock of buildings that are not sufficiently designed and constructed to an acceptable building code. Conducting research to better understand simultaneous hurricane-induced wind, rain, and debris effects on the built environment will lead to innovative design technologies that can mitigate hurricane wind damage. The International Hurricane Research Center (IHRC) at the Florida International University (FIU) has developed a new research approach to better understand categories 1 to 5 hurricane-induced effects on residential buildings and other structures through full-scale, destructive testing, much the same way that the automobile industry tackled the crash worthiness issue or the earthquake community approached building safety. This research will foster the development of novel mitigation techniques to improve our built environment's resilience to hurricane impact. To develop these advanced techniques, we will subject test models of representative building structures or appropriate portions of such structures to hurricane-induced wind–rain–debris effects in a controlled and repeatable environment using the Wall of Wind testing apparatus developed by the IHRC. Through such full-scale destructive testing, performance-based evaluation, and failure-mode analysis, innovative mitigation techniques will be developed. Wall of Wind experimentation has the potential for revolutionizing our building and retrofitting practices.

Western Europe's de-polderisation policy was launched in the 1980s and has since spread along the coasts, especially in the UK, where it is governed by coastal defence objectives through “managed realignment” and environmental objectives that are predominant elsewhere. Various means of de-polderisation exist: through tidal gates, breaches, or sea dike removal. Although physical studies on de-polderisation should be continued, it is equally important to examine the social context, favouring or not, of marsh restoration because acceptance of any de-polderisation scheme largely depends on public opinion. The results of five opinion surveys carried out in France and the UK were thus compared and revealed diverging opinions or unexpected indifference toward de-polderisation. A profile of those opposed shows that they are relatively old and regularly frequent the de-polderised sites or live near them. “Negative” reactions, however, are also linked to a lack of knowledge about the marsh environment and of the effects of de-polderisation. Other explanations surface as well: that today coastal environments are quite simply viewed as “landscape,” the degree of human intervention in the implemented schemes, the physical and eustatic context, and the degree to which people are informed. Public knowledge could be improved and mentalities changed through better communication methods, especially on a local level. Furthermore, the creation of a “variables bank” capable of explaining public attitudes and perceptions more systematically would also improve “social management” of the de-polderisation policy.

Detecting the morphologic change of intertidal shoals from satellite images is severely hampered by the requirement that they be acquired at the same tidal height. This limitation is circumvented with a new detection method proposed in this paper. It is based on the median line of tidal channels from which the stability of adjoining intertidal shoals is inferred. This method was applied to detect the changes of intertidal shoals in the vicinity of Jiangang Town in Jiangsu Province of East China from seven Thematic Mapper images recorded between 1988 and 2003. The delineated median lines of three tidal channels from the seven images were overlaid with each other in MapInfo. It is found that the net positional change of a channel varies with its section. The closer a section is to the shore, the larger change it underwent. On average, the magnitude of change in a section ranges from 25 to 134 m per annum. Temporarily, all three channels experienced more changes in early than in recent years of the study. The intertidal shoals have shifted their boundaries at a rate of about 110–150 m per annum, which would decrease further offshore. It is concluded that the intertidal shoals have shown some degree of stability over the study period.

Surf forecasts are vital for safety, property protection, and planning of coastal activities. In Hawaii, surf is frequently dangerous during the boreal fall through spring for northwest- through north-facing coastal areas, which are characterized by narrow shelves, steep bottom slopes, and zones of high refraction. Forecasts of deepwater wave characteristics have improved with the advancement of the Wave Watch III model. A waverider buoy located 5 km northwest of Waimea Bay, Oahu measures the deepwater wave field. Although the offshore wave field is well forecasted and observed, the transformation to surf heights has not been clearly defined and verified. This paper describes an empirical method for estimating breaker heights derived from a comparison of Waimea buoy measurements and north shore, Oahu daily surf observations, which nominally represent the H_1/10 for the locations with the highest reported surf and have been recorded in Hawaii scale. The first task of this study is to translate the visual surf observations from Hawaii scale to trough-to-crest heights. The results show that the trough-to-crest heights are twice the Hawaii scale values within the 10–20% margin of error for the full range of breaker sizes encountered in Hawaii. The empirical method is resolved by deriving a coefficient of refraction on the basis of comparisons of the trough-to-crest surf observations with the shoaling-only, estimated breaker heights, which are calculated from the Waimea buoy's significant wave heights and dominant periods. The resultant formula uses offshore wave height and period to estimate surf heights, which represent the H_1/10 for zones of high refraction, i.e., nominally the areas of highest surf. The empirical formula should be applicable to other coastal zones of the world with similar geophysical traits and could serve as a scale reference for coastal wave models, such as the Simulating Waves Nearshore model.

A three-dimensional numerical model is described to study and investigate the impact of the Orissa super cyclone on the ocean. The forcing mechanism in the model is the wind stress derived from moving cyclonic storm/satellite winds. Numerical experiments have been performed using the model in order to understand the dynamics and thermodynamics of the ocean owing to the cyclone crossing the Paradip coast. The model was used to simulate the thermal response of the ocean to study the surface cooling and the surge associated with the cyclone. A net decrease in sea-surface temperature of about 5–6 °C and a peak surge of over 6 m were simulated when the storm moved over the Orissa coast. The model computations were compared with the satellite data (TMI—Tropical Rainfall Measuring Mission [TRMM] Microwave Imager) available during the storm period. In the subsequent experiments, the variation of the ocean's response to the changes in the translation speed of the cyclone was examined. We conclude that the speed of the cyclone, which determines the resident time of the cyclone over the ocean, leaves an overwhelming influence on sea-surface cooling and surge generation.

Oil-related activities such as single point mooring (SPM), installation, navigation, marine transportation, and oil exploration all have the potential to cause oil spills and pose major threats to the coastal ecosystem along the Indian coast. The Gulf of Kachchh, a biologically rich ecosystem composed of mudflats, submergible shoals, islands, sandy beaches, rocky shore, coral reefs, and mangroves, is located along the northwest coast of India. Its proximity to the Persian Gulf has attracted the establishment of facilities for transferring, piping, and loading of crude oil and petroleum products, mainly the Arabian crude. The marine ecosystem of the gulf is always at risk due to accidental and operational oil spills in the gulf. In this paper, an attempt is made to identify the resources that are at risk due to such oil spills. An integrated numerical simulation modeling approach has been applied to generate the probable oil trajectory and fate analysis, and the results have been integrated into geographic information systems (GIS) to locate and estimate the resources at risk. Sensitivity analysis of the resources available in the study area was carried out in order to set the resource protection priorities in the event of an oil spill.

The application of optically stimulated luminescence (OSL) to the dating of recent aeolian sand ridges on Rømø, an island off the southwest coast of Denmark, is tested. These sand ridges began to form approximately 300 years ago, and estimates of the ages are available from historical records. Samples for OSL dating were taken ∼0.5 m below the crests of four different dune ridges; at least five samples were recovered from each ridge to test the internal consistency of the ages. Additional samples were recovered from the low lying areas in the swales and from the scattered dune formations in a broad hummocky area landward of the well-defined ridges. Despite low luminescence signals, we were able to obtain a mean age for the youngest ridge of 17 ± 2 years, consistent with the known age of >28 years. Optical ages of individual samples in our study ranged between 10 ± 3 years and 690 ± 50 years, and all ages were broadly consistent with those expected from historical information. The oldest aeolian surface on Rømø appears to be 370 ± 30 years. This is built on what we interpret as a marine sandbank, whose surface is ∼700 years old. The sand ridges seaward of the hummocky dune field have well-defined building phases separated by inactive periods and the first major ridge formed ∼235 years ago. This study demonstrates that optical dating can be successfully applied to these young aeolian sand deposits, and we conclude that OSL dating is a powerful chronological tool in studies of coastal change.

The devastating December 26, 2004, tsunami produced abundant geologic effects along the Andaman coast of Thailand. The tsunami inundated the numerous sandy beaches and flowed over the adjacent aeolian dunes. On some of the dunes, the tsunami scoured circular holes 10–30 cm in diameter, and in its waning phases, it coated the holes with mud. The tsunami locally deposited a sand sheet that ranged from 0–30 cm in thickness, with an average thickness of approximately 10 cm. Sedimentary structures within the sand sheet include ripples from inflow and outflow, graded bedding, parallel lamination, and double-layered deposits. Erosion, locally severe, affected sand beaches and tidal inlets. We use these erosional and depositional features to infer the main processes that acted during inundation from the tsunami.

Wan-an Island is one of the most stable green sea turtle nesting sites in Taiwan. Each of the 11 beaches is characterized by various width, slope, grain size, and vegetation coverage. The digging success of the gravid female turtles on this island varies a great deal, and the average value is not high. Many investigations have demonstrated that the nest environment can influence the nest site distribution. The major environmental factors include: substratum compactness, vegetation coverage, grain size, and porewater content. Results of this study indicated that the substratum compactness is directly or indirectly influenced by other factors. This, in turn, would affect the digging success directly. The vegetation coverage can not only influence the substratum compactness but may act as an inducing factor for digging. As a result, the substratum compactness and vegetation coverage may be the most important environmental factors that influence the nest site distribution on Wan-an Island. The different combinations of various environmental factors might result in the high variation in digging success. Based on the result of this study, a hypothesis of nesting behavior of the green turtle on Wan-an Island is proposed. This is the first study ever that has demonstrated quantitatively the influence of beach characteristics on the nest site selection of the green sea turtles.

From November 2 to 5, 1996, an intense extratropical cyclone was near the National Data Buoy Center buoy 46035 in the Bering Sea. At the storm's extremes, the buoy measured minimum sea-level pressure (= 966.1 mbar), 10 m wind speed (= 28.2 m/s), peak gust (= 38.9 m/s), significant wave height (= 15.4 m), and peak period (= 16.7 s). During this period, 41 hourly observations were recorded when the waves were not fully developed; these records are the subject of our detailed analysis. It is shown that the wind–pressure relation was governed by the cyclostrophic equation; stability was neutral (i.e., the logarithmic wind profile law is useful); the relation between dimensionless wave height and period as normalized by the wind speed and the friction velocity follows the formulas found in the literature. Further determination of the friction velocity using the gust factor concept is successful to incorporate both tropical and extratropical cyclones.

The Bonnet Carré Spillway was constructed in 1931 to divert floodwater from the Mississippi River into Lake Pontchartrain, an oligohaline estuary near New Orleans, Louisiana. The spillway was opened from March 17 through April 18, 1997. Infaunal macroinvertebrate population, surface and bottom salinity, and dissolved oxygen data were examined to determine the effects of this diversion. These data were obtained from November 1996 through November 1998 from five sites on an east-to-west transect across Lake Pontchartrain. A community composed of oligohaline taxa persisted during the freshwater period, but changes in dominance, and to a lesser extent composition, occurred over time and among sites. There was a pronounced spatial effect related to the distance of the sites from the spillway and from tidal passes. Based on decreases in species diversity (H′), abundance, and the number of taxa, it appears that the opening had a deleterious impact on the benthos. The cause of these changes cannot be attributed with certainty to any one factor, but we speculate that they were the result of reduced salinity, cyanobacterial blooms, and hypoxia/anoxia. Although recovery occurred, based on overall changes in macroinvertebrate abundance and Rangia cuneata clam biomass, there was no evidence of increased benthic invertebrate productivity.

A recent study reveals that more than 60,000 miles (>96,500 km) of coastal roadways are in the 100-year floodplain in the United States and vulnerable to the attacks of water surges and storm waves generated by hurricanes. Mitigating the effects of coastal flooding requires accurate predictions of the destructive hydrodynamic forces. This study demonstrates a methodology for integrating state-of-the-art storm surge and wave prediction models as an effective tool for engineering design of coastal infrastructure and facilitation of hurricane emergency management. The methodology has the capability of resolving complex geometry and topography typical of coastal road flooding. The surge model incorporates moving shoreline conditions associated with flooding and allows for nonlinear interactions among astronomical tide, storm surge, and wave setup. The wave model takes into account the unsteadiness of wind forcing, currents, and water levels. A historical hurricane event is simulated for the landfall of Hurricane Georges (1998) on the north coast of the Gulf of Mexico. Good agreement between the modeled and measured surge hydrographs in Mobile Bay, Alabama, has been found. The advanced surge model (ADCIRC), coupled with the wave model, successfully simulates the inundation and measured high water marks along two highways adjacent to the bay. The third-generation wind wave model (SWAN) coupled with the hydrodynamic model reveals the temporal and spatial variability of wave heights and wave periods in the Mobile Bay estuary and on the flooded highways. Numerical experiments were carried out to examine the response of the estuary to various forcing agents, including the offshore surge hydrograph, local wind forcing, and wave thrust.

This study analyzes the detailed nonlinear wave–wave interactions during 6 hours of wave generation in a mistral event. Nonlinearity and phase coupling are computed using wavelet bicoherence, which is a new technique in analyzing wind–wave and wave–wave interactions.

Computations of wavelet bicoherence are conducted for the 13 continuous records of measured wave data. The phase coupling and nonlinear wave–wave interactions are shown to occur at different bicoherence levels, and these levels are different from one record to another. Furthermore, the study shows that there is an increase in nonlinear wave–wave interaction with time.

The Gulf of Kachchh (Gulf), India, an ecologically rich habitat, has a wide variety of activities, such as extensive salt farming along the coast, brine release from salt farms, maintenance dredging by ports and disposal of dredged material, release of hot water from thermal power plants, and navigation. Management of coastal and marine areas by maintaining the balance between the developmental activities and protection of marine environment is a challenging task for coastal managers and requires a complete understanding of the physical, chemical, and biological aspects of the system. In this study, a two-dimensional hydrodynamic model (MIKE-21) was developed for Gulf of Kachchh with rectangular grid resolution of 450 by 450 m to understand the role of circulation pattern for mixing capacity of the Gulf. The model was calibrated with tide and current at predetermined locations. The model predictions show good agreement with the measured tide and current data. The model-predicted amplitudes and phases of major tidal constituents at four locations compare well with the observed data. The root mean square error for model predictions was found to be within 10%. Analysis of residual currents obtained from a 29.5-days simulation revealed the formation of eddies in the outer Gulf. Presence of these eddies and the magnitudes of residual currents indicate the mixing capacity of the central and outer Gulf. The results strengthen and extend understanding of circulation and mixing patterns in the management of the habitat.

This paper presents time-series data collected from four shallow mooring stations located in the inner part of Mobile Bay, Alabama, during the passage of Hurricane Ivan in September 2004. Sharp changes in salinity and its gradient were observed in the open part of Mobile Bay even before Ivan landed. Increases in water level (2.20–2.43 m) and salinity (7–11 practical salinity units) during the passing of Ivan were large enough to double mean depths and background salinities, respectively, in the relatively secluded areas of the Mobile-Tensaw Delta. Large diel variations in dissolved oxygen, as large a daytime increase as 9.7 g m⁻³, were observed in the Mobile-Tensaw Delta after landfall of Ivan. Community metabolism rates estimated using the diel oxygen curve method show that both the production and the respiration rates increased by 2–3 times after Ivan passed, suggesting that supersaturation dissolved oxygen conditions in the afternoon were the result of high primary production driven by storm-enhanced input of nutrients and that low dissolved oxygen conditions in the following morning were the result of high community respiration of storm-enhanced input of organic matter from benthic sediments and inundated wetlands.

The accuracy of elevation measurements obtained with a recently described one-person beach profiling method is examined. A reanalysis of the available data indicates that the accuracy of this method is below the reported average of 99.76%, and actually ranges from about 91% to 99%. Of greater concern, the absolute error in elevation measurements (average = 15 cm, maximum = 35 cm) is shown to be large enough to potentially exceed temporal changes in profile elevation, effectively rendering those changes undetectable. It is suggested that the acceptable level of error for a given project be carefully considered prior to adoption of this method.