Australia is one of the driest continents on earth with most interior lands classified as steppe or desert. With an expanding coastal population pushing farther inland, the need for freshwater increases for urban use, agriculture, and industry and because there is little freshwater at the surface and most of the groundwater is too saline and generally unsuitable for multiple uses, new sources of freshwater must be sought to sustain future development of Western Australia's interior. To mitigate this ongoing macroproblem, it is proposed to establish a new Southern Ocean maritime sea-lane between Antarctica and Western Australia with the first large-scale deployment of very capacious floating liquid freshwater containers (Stauber bags), barges hauled and shuttled regularly by carousel-type supertugboats to convey a directly acquired, essentially cost-free, bulk-harvested potable subglacial Antarctic meltwater possibly siphoned from beneath the floating Amery Ice Shelf and transported to Western Australia. Access of the floating liquid freshwater containers to Perth, the capital city, would be up-slope the offshore Perth Canyon to the continental shelf. Stored containers could lay off in the lee of Rottnest Island at the Perth Terminal. From there, freshwater could be transported to wherever needed in coastal rural and urban Western Australia. On land, Pecero self-rolling bags could be used to distribute all imported freshwater farther inland and serve also as stationary (parked) reservoirs. Stock watering, farm irrigation, and drinking water as well as mineral mine, petroleum refinery, and sewage treatment processing are likely additional income-producing consumptive users. Both bulk long-distance conveyance and long-term storage on land by such means will naturally reduce the present-day stress on Western Australia's domestic water supplies, storage, and delivery systems that are limited by regional climates with long-term seasonal dryness. Freshwater imported would absolutely reduce freshwater stress on Western Australia's excessivelyexploited rivers and excessively mined aquifers.

Light detection and ranging (LIDAR) techniques, combined with Global Positioning Systems (GPSs), make it possible to obtain accurate topographical and bathymetric maps, including maps of shoreline positions. LIDAR surveys can produce 10- to 15-cm vertical accuracy at a spatial resolution greater than one elevation measurement per square meter. This meets the requirements of many coastal research and management applications of LIDAR, including flood zone delineation, monitoring beach-nourishment projects, and mapping changes along sandy coasts and shallow benthic environments from storms or long-term sedimentary processes. Typically, a LIDAR sensor may collect data down to depths of about three times the Secchi depth. If the depth or the water turbidity is too great, acoustic echo-sounding is used. Airborne LIDARs have also been applied with hyperspectral imagers to map wetlands, beaches, coral reefs, and submerged aquatic vegetation (SAV). The objective of this article is to review the use of LIDAR techniques for collecting topographic and bathymetric data and to present three case studies, including lessons learned from each.

Natural and anthropogenic impacting factors simultaneously cause wetland loss in the Louisiana coastal area. Ongoing natural processes are integrated with anthropogenic impacting factors to rationalize the contribution of each impact type within a total system. From baseline conditions of today, two natural processes account for approximately 85% of the estimated cumulative land loss by 2050: (1) subsidence by sediment compaction and tectonism that is driven by the weight of the Mississippi Delta's sedimentary pile and (2) absolute sea-level rise. Hurricanes are sudden natural processes that act as impact accelerators. After the Mississippi River became hydrologically isolated from the delta it built, anthropogenic impacts coinciding with the ramp up to peak oil production in the Louisiana coastal area caused many direct impacts, such as the construction of access canals and pipelines, but indirect impacts are largely symptomatic of natural delta platform submergence. Formation extraction is the only significant anthropogenic activity influencing projected land losses: about 6%. Other anthropogenic activities, such as onshore development, maintenance dredging, and oil spills, are not significant impacting factors. Additive processes, such as delta outbuilding and coastal restoration, are also not significant. A growing body of Louisiana coastal area subsidence studies is proceeding in absence of insight as to how conclusions might be ordered by the subsurface structural fabric that has influenced coastal geomorphology and that continues to influence surface processes. Subsidence assessments have been heavily weighted with inputs based on surface and near-surface data sets that are easy to see and touch. Approaches using basin analysis techniques are a critical omission. Such outputs integrate subsurface geologic logs and seismic data sets into products able to inform decisions about locating coastal restoration or flood protection projects and avoid areas of geologically persistent subsidence.

Heterotheca subaxillaris (J. de Lamarck) N. Britton & H. Rusby is a New World aromatic, pioneer species that rapidly colonizes disturbed, xeric habitats on temperate and subtropical coastal dunes. Also known as camphorweed, H. subaxillaris has low moisture requirements, and it tolerates low nutrient levels and high sand temperatures. Dimorphic achenes have a dual germination strategy. Disc achenes are nondormant, and seeds germinate over a wide range of temperature conditions, whereas ray achenes are dormant at maturity and require after-ripening before seed germination. Heterotheca subaxillaris competes well with other species in disturbed sites, but growth and reproduction are inhibited when it is in competition with dominant dune grasses.

Information regarding the present condition, historical status, and dynamics of mangrove forests is needed to study the impacts of the Gulf of Mexico oil spill and other stressors affecting mangrove ecosystems. Such information is unavailable for Louisiana at sufficient spatial and thematic detail. We prepared mangrove forest distribution maps of Louisiana (prior to the oil spill) at 1 m and 30 m spatial resolution using aerial photographs and Landsat satellite data, respectively. Image classification was performed using a decision-tree classification approach. We also prepared land-cover change pairs for 1983, 1984, and every 2 y from 1984 to 2010 depicting “ecosystem shifts” (e.g., expansion, retraction, and disappearance). This new spatiotemporal information could be used to assess short-term and long-term impacts of the oil spill on mangroves. Finally, we propose an operational methodology based on remote sensing (Landsat, Advanced Spaceborne Thermal Emission and Reflection Radiometer [ASTER], hyperspectral, light detection and ranging [LIDAR], aerial photographs, and field inventory data) to monitor the existing and emerging mangrove areas and their disturbance and regrowth patterns. Several parameters such as spatial distribution, ecosystem shifts, species composition, and tree height/biomass could be measured to assess the impact of the oil spill and mangrove recovery and restoration. Future research priorities will be to quantify the impacts and recovery of mangroves considering multiple stressors and perturbations, including oil spill, winter freeze, sea-level rise, land subsidence, and land-use/land-cover change for the entire Gulf Coast.

Scenery is a resource that has to be evaluated in an objective and quantitative manner to provide a means of comparison against other resource considerations and environmental impact assessments. This article presents the results of a quantitative evaluation of coastal scenery, enhancing the previous public survey questionnaires for Turkey, the U.K., Malta, and Croatia. The technique developed to evaluate coastal scenery uses 26 scenic parameters (of both physical and perceptual characteristics) for the four countries listed above and also for Australia, Ireland, the United States, New Zealand, and Japan, assembled via consultations with coastal users and experts. The weights of the scenic parameters are estimated and, together with a checklist that uses a fuzzy mathematics approach, an evaluation index (D) for each site is estimated for 86 worldwide coastal regions. These sites are further classified into five categories according to the D values they achieved. The results show that human impacts may adversely affect the coastal scenic value of a site. Comparison between assessment grades from experts and those from the public showed good agreement, specifically for human parameters. The results could be quite useful as a guideline for assessing, designing, and managing coastal areas when decisions must be made regarding intensive urban and industrial developments.

This article defines short-term (tidal cycle) sediment-transport patterns at a backbarrier beach based on detailed field studies. Fieldwork was planned to record nonstorm, spring tide conditions that enable the definition of background sediment dynamics at the study area. The experiment was set at two beach morphologies: beach face and sandbank. Current meters were deployed at both sites. Fluorescent tracer techniques were applied to determine rates and direction of transport. Topographic surveys and sediment sampling were undertaken. During the experiment, limited tracer displacement and small morphological changes occurred. The low magnitude changes are representative of predominant, low-energy hydrodynamic conditions. Sediment transport was primarily longshore orientated and dependent on the velocity of tidal currents. Tidal currents had the potential for sediment transport only during a short period of the tidal cycle and had higher velocities during ebb, which results in a net sediment transport orientated towards the nearby inlet. It is suggested that there is dependence on sediment transport rate at the study site and on the variability of tidal currents, which are greatly influenced by the distance to, and conditions of, the nearby Ancão Inlet.

O presente artigo define os padrões de transporte sedimentar, a curta escala de temporal (a nível do ciclo de maré), para uma praia interna localizada no interior de um sistema de ilhas barreira. Os trabalhos de campo decorreram durante um clima de não tempestade, em regime de marés vivas, permitindo a definição das condições morfodinâmicas de base da praia. A experiência incidiu em duas morfologias, na face de praia e num banco arenoso paralelo à praia, localizado na parte terminal do perfil. Em cada uma dessas morfologias foi colocado um correntómetro. Nos mesmos locais procedeu-se ainda à colocação de traçador fluorescente, para aferir a taxa e direcção de transporte sedimentar. Foi ainda efectuado um levantamento topográfico da área total, e colheita de sedimento superficial. Na generalidade, observou-se fraca deslocação do traçador desde o ponto de injecção, bem como a ocorrência de alterações morfológicas pouco significativas. O clima de não tempestade a que se associam estas fracas alterações morfológicas representa as condições hidrodinâmicas típicas da praia. O transporte sedimentar é maioritariamente longilitoral, sendo controlado pela velocidade da corrente de maré. As correntes de maré apresentaram potencial para desenvolvimento de transporte sedimentar durante um curto período do ciclo de maré, com maiores velocidades em vazante. Em resultado, o transporte sedimentar é preferencialmente orientado para a barra de maré. Assim, sugere-se a existência de uma dependência entre a magnitude do transporte na área de estudo e as correntes de maré, directamente relacionadas com a Barra do Ancão.

Marine features associated with Late Quaternary isostatic adjustment are well documented in central and coastal Maine, United States. However, the effects of glacially induced land-surface tilting in the interior of the state and its affects on coastal landforms are not well understood. Investigations at Moosehead Lake, Maine's largest lake, indicates that isostatically forced tilting shifted the lake's outlet from the Penobscot River drainage to the Kennebec River drainage, resulting in a significant effect on marine delta formation through changes in the discharge and competence of the Kennebec and Penobscot Rivers, two of the largest in the region. Historic stream-gage data are used as an analogue to quantify the effect of the outlet shift on the relative discharge of these two rivers. These data suggest that, in the upper portions of the watersheds, the Penobscot River lost approximately 25% of its annual discharge, while the Kennebec River experienced an approximately 74% increase in annual discharge. The timing of this change, established in the abandoned lake outlet into the Penobscot River, coincides with the end of deposition of the Penobscot paleodelta in Penobscot Bay and the onset of deposition of the western lobe of the Kennebec paleodelta. This indicates that changing river discharges were also linked to changes in sediment loads at the rivers' mouths. In addition, these findings imply that coarse-grained fluvial deposits (North Anson Formation) identified in the upper Kennebec valley may be the result of the rapid and large increase in river discharge associated with the divide shift. Recognition of both marine and fluvial features associated with isostatic adjustment emphasizes the importance of this process on early postglacial landscape formation.

An empirical time series (1941–2007) of advance and retreat data from the coast of Guyana is modeled with statistical time-series techniques. Subseries of 5-y periods are fitted to modified Box-Jenkins space–time models. Second-order spatial-cyclic autoregressive models, associated with cyclical advance and retreat patterns, fit the data for five different subseries. First-order autoregressive models are also suitable to describe the data from five other subseries, thereby suggesting a long-memory response in the coastal system. Three of the subseries are fitted to space–time autoregressive moving-average models, thereby indicating the presence of random shocks (i.e., random events) in the coastal system. The various models are indicative of cyclical, long-memory, and short-memory processes operating in the coastal system. These processes can be associated with mudshoal propagation and stabilization and with temporal stochastic processes that force the coast to advance or retreat in different locations.

Seawalls remain one of the most widely adopted coastal-protection measure. The seawalls should be stable to ensure safety and optimally use the coastal space with a minimum or no waves overtopping but still keeping the crest elevation low. This may possibly be achieved by reshaping the front of the structure in such a way that it offers maximum resistance to the flow or enhances the dissipation of incident wave energy. With this as the background, an experimental study measuring run-up and overtopping of three different types of curved-front face seawall models, as well as the dynamic pressures exerted on each of them, was carried out. The measured parameters for the three types of seawalls are compared with that for a vertical seawall. All the tests were carried out with the models rigidly fixed over a bed slope of 1 in 30 in a wave flume and subjected to the action of regular waves. The details of the test facility, models, experimental program, results, and analysis are presented and discussed in this article.

Our objective was to characterize a barrier island dune chronosequence to determine the relationships between spatial distribution and specific physiological strategies for forb survival in a high stress environment. Specifically, we hypothesized that (1) forbs on dune crests, where water is less available, would exhibit higher water-use efficiency (WUE) with higher δ¹³C compared with the front and back of each dune, (2) forbs on the primary dune where soil N is lowest would exhibit higher N use efficiency (NUE) with lower C∶N ratio compared with forbs on secondary and tertiary dunes, and (3) the taprooted annual, Conyza sp., would have a lower WUE and NUE compared with two shallow-rooted biennials. For each species, we determined leaf C∶N, %N, δ¹³C, relative water content, and total chlorides. Environmental characteristics quantified on each dune included depth to water table and soil chlorides, organic matter, and pH. No significant differences were found for δ¹³C across dune positions or C∶N values across dune ages; therefore, these two hypotheses were not supported. Conyza sp. had the lowest δ¹³C and C∶N ratio, which supports our hypothesis that Conyza sp. would have the lowest WUE and NUE and might have more access to resources compared with Cirsium and Rumex species. Cirsium sp. had the highest δ¹³C (−27.1 ± 0.1‰), indicating greater WUE. Cirsium sp. also had the largest range of C∶N values, suggesting a more plastic NUE. Higher WUE and NUE may partially explain why Cirsium sp. was the only species found at every site.

The main geomorphological features of dunes/beaches were investigated along the central Adriatic coast of Italy (Abruzzo). Nine foredune areas typified by established dunes and incipient dunes were investigated through detailed geomorphological surveying and an analysis of historical maps and photographs (aerial and land). The dunes are located along both low and high coasts. The morphology is typical of foredunes, with elongated fields parallel to the coastline. The total linear extension is ∼15,500 m; established dunes are more extended than incipient ones and occupy the greatest portion of the total surface area (∼1,500,000 m²). Analyses of historical maps and photographs (aerial and land) led to the reconstruction of coastal dune morphology from the beginning of the 1800s to the turn of the 20th century, showing a surface reduction >80%. Accelerator mass spectrometry ¹⁴C dating, carried out on samples of Helix sp., outlines the minimum age of Abruzzo dune systems at about 730 ± 40 years before present. The overall study enabled the reconstruction of different geomorphological arrangements of the dune areas, allowing us to define the dunes of the Abruzzo coast as seminatural foredunes, with mainly direct and locally indirect management control. The reconstruction of dune evolution identifies Abruzzo's oldest recognizable period of aeolian deposition in the late Middle Ages; aeolian deposition was widely active until the early 1900s and dunes were a significant morphological component of the Italian coastal landscape. The first significant human-induced processes began in the 1900s; over the last 50 years human activity has played an important role in the coastal morphogenesis, with direct and indirect effects on coastal dune reduction and removal heavily affecting the whole coastal system.

Mexican coasts with aquaculture potential have been divided into 11 homogeneous coastal units (HCUs) based on zoning criteria related to economic activities, available infrastructure, population density, potential space availability, and exposure to hurricane impact in coastal municipalities. Data were obtained from the 2004 economic census, the 1990 population census, and the 2005 population count of Mexican coastal municipalities. Fishing occurs in all HCUs and employs the largest number of people among analyzed economic activities, followed by tourism (represented by the number of people working in hotels, motels, and similar establishments). Mining, particularly associated with petroleum, employs the third largest number of people; however, this activity is concentrated in the Gulf of Mexico. Aquaculture (primarily of shrimp) employs the smallest number of people among analyzed activities and is more prevalent on the Pacific coast. Based on criteria used to assess coastal space, Pacific coastal areas corresponding to HCUs located in northwestern Mexico and on the Yucatan coast, possess the most suitable natural conditions for aquaculture activity in sheltered coastal spaces.

A time series of relative abundance of Atlantic menhaden Brevoortia tyrannus was compared with concomitant time series of phytoplankton and zooplankton abundance in the York River, Virginia. Menhaden catch-per-unit-effort (CPUE) was measured from pound net catches and disaggregated by fish size. Phytoplankton and zooplankton were enumerated and assigned to general taxonomic categories from collection stations in proximity to the pound nets. The CPUE data were divided into juvenile and adult categories and segmented over time based on transition points in the time series identified using sequential t test analysis of regime shifts (STARS). Transitions in adult CPUE were more closely associated with transitions in zooplankton abundance than with changes in phytoplankton abundance. The data suggest that menhaden adjust their mesoscale distributions within a large estuarine system like Chesapeake Bay based on changing patterns of zooplankton prey and independently of phytoplankton blooms. This distribution preference is attributed to the efficiency in which the fish filter various sizes of particles from the water column. The exception to this trend occurred in late summer when menhaden abundance declined in the York River despite the high abundance of suitable prey. This was likely the result of a bloom of the ichthyotoxic dinoflagellate Cochlodinium polykrikoides, which maintained densities known to be lethal to fish for 1 month. Collectively, these results suggest that adult menhaden play a minimal role in providing ecosystem filtration and may actually promote primary production through the removal of zooplankton grazers and the excretion of nutrients.

In this study, a volume of fluid–based flow model is developed to calculate the wave run-up along a sloping bottom or a moving vertical wall. The model equations are continuity and momentum equations, which are solved numerically for the values of fluid velocity and pressure using the finite-difference scheme. The moving free surface is traced according to the concept of volume of fluid, with calculated net change of fluid flux for updating the new position of the free surface. This model is applied to study the piling up of a nonlinear free surface in front of an impulsively moving wall. The results in terms of free-surface elevation and pressure distribution for various moving-wall conditions are presented with the comparisons to available experimental data. Model application is also performed by simulating propagation of nonlinear shallow-water waves (solitary waves or cnoidal waves) and the process of wave run-up along a sloping bottom. The predicted wave elevations and run-ups are found to agree reasonably well with other published numerical solutions and measured data.

River runoff into Ría de Viveiro presents great seasonal variability due to the region's climate—but always in the context of discharge values that are small relative to the size of the estuary. This work has two main objectives: (i) to implement the first numerical model of ría hydrodynamics and (ii) to determine whether the river discharge variability has significant effects on the system and, if so, which. The numerical model, which takes into account all driving agents (tides, river discharge, and winds), is successfully validated based on sea level and flow velocity observations, with very high correlation coefficients. It is then applied to different study cases representative of typical summer and winter scenarios. Three main conclusions can be drawn: (i) The flow is primarily tide driven. (ii) However, the river discharge is not without significance—it causes ebb–flood asymmetry with ebb dominance. (iii) The main consequence of the seasonal variability of river discharge is the seasonality of the ebb–flood asymmetry itself. Weak and essentially confined to the inner ría in summer, it gains strength in winter and extends to the outer ría, where different flood and ebb patterns arise.

In this study, a wave-damping rate was derived for waves propagating over a multilayered, permeable seabed of finite depth. For a single-layer bed, a monogram is presented for the relationship between the wave-damping rate and the relative water depth for various depths of the permeable bed. The derived damping rate was used in the extended mild-slope equation to calculate wave dissipation over the permeable bed. For a single-layer bed, the result from the extended mild-slope equation model was compared with the result from the integral equation method and showed good agreement. The extended mild-slope equation model was also used to examine the wave transmission over a permeable shoal with a various number of layers, each with a different permeability. In general, short waves are more influenced by the permeability of the shoal than long waves unless the water depth is so great that the influence of the permeable bed on the surface water waves disappears. For a multilayered bed, the influences of the permeability of the upper layer on wave dissipation and transmission are more significant than those of the lower layers.

The U.S. Geological Survey and other federal and state agencies have been collecting continuous temperature and salinity data, two critical estuarine habitat variables, throughout San Francisco estuary for over two decades. Although this dynamic, highly variable system has been well studied, many questions remain relating to the effects of freshwater inflow and other physical and biological linkages. This study examines up to 20 years of publically available, continuous temperature and salinity data from 10 different San Francisco Bay stations to identify trends in temperature and salinity and quantify the salinity–freshwater inflow relationship. Several trends in the salinity and temperature records were identified, although the high degree of daily and interannual variability confounds the analysis. In addition, freshwater inflow to the estuary has a range of effects on salinity from −0.0020 to −0.0096 (m³ s⁻¹) ⁻¹ discharge, depending on location in the estuary and the timescale of analyzed data. Finally, we documented that changes in freshwater inflow to the estuary that are within the range of typical management actions can affect bay-wide salinities by 0.6–1.4. This study reinforces the idea that multidecadal records are needed to identify trends from decadal changes in water management and climate and, therefore, are extremely valuable.

We outline some misconceptions and methodological deficiencies presented in the comparison of four types of aeolian saltation sensors. Specifically, we clarify the sampling area, operation, and response of the sensors and comment on the methodological challenges for field-based sensor comparisons. The goal of this discussion is to clarify some inconsistencies that may influence the selection of one sensor over another in future research. Indirectly, we hope to highlight research needs and improve the reliability of aeolian transport measurements.