Rip currents are fascinating, natural, surf zone phenomena that occur daily on many beaches throughout the world. My colleagues, students, advisors, and I have been studying rip currents for more than 10 years and have performed more than 10 comprehensive field experiments on various beaches throughout the world using different observational techniques and model simulations to improve our understanding and prediction of rip currents. We have written a series of scientific articles describing the intricacies and complexities of rip current behavior using statistical and mathematical equations. These manuscripts are typically published in professional journals, which often do not communicate our results to those who would benefit from the information—the beachgoing public and ocean swimmers. Herein, we summarize our findings to help people of all ages gain a better understanding of currents at the coast.

Australia's so-called “Dead Heart,” its hot arid interior landscape, can be brought into irrigated agricultural production with the importation of extracontinental freshwater supplies originating in Papua New Guinea. Despite Queensland's La Niña-caused historic and costly 2010 to 2011 river flooding induced, in great part by tropical cyclone Yasi, its westernmost torrid region is classed as arid, currently almost without any irrigation agriculture present. Freshwater importation from Papua New Guinea's Fly River via an undersea pipeline mostly skirting the Torres Strait could increase the value of Queensland's little-used dryland Outback and, perhaps, establish new overseas markets in Asia for exported agricultural products. An induced perennial Diamantina River could replenish groundwater recharge regions (Great Artesian Basin) and convert Lake Eyre to a permanent lake of slightly brackish water. Irrigated eucalyptus tree plantations might serve, in part, to counter some Earthly global warming. The Torres Strait Islanders will benefit economically as well as other social groups on the mainland of Papua New Guinea. Here we examine closely some of the technical aspects of a Papua New Guinea-Queensland (PNG-QLD) Undersea Freshwater Pipeline Macroproject (UFPM) installation. We offer a choice of two routings for the PNG-QLD UFPM (Case A) while at the same time making clear our informed preference.

To establish existing conditions for dredge material beneficial use projects and to help implement principles of Regional Sediment Management (RSM) into projects and studies, this paper is an assessment of sediment sources and sinks, physical processes, and longshore sediment transport along the west and south shore of Lake Erie. This summary compiles information from a widely scattered technical literature and synthesizes the results in preparation for development of a sediment budget.

The U.S. shore of Lake Erie has 28 river or harbor mouths protected with jetties and structures, of which 16 are Federal navigation projects. Much of the sediment management since the mid-1800s has revolved around providing safe navigation, maintaining depth in navigation channels, and disposing of the dredged material.

Sediment sources include material brought down the rivers (often fine-grained); industrial dumping and runoff from sewers, gravel, sand, and clay eroded from glacial till bluffs and clay banks; sediment created in situ from bedrock bluff weathering (primarily from shale); and limited supply from lake bed lowering and offshore outcrops. Losses include wave- and ice-induced transport to deep water, sediment trapped in fillets at harbor jetties, sediment dredged from harbor entrance channel and placed in confined disposal facilities (CDFs) or placed offshore, bluff armoring, and (formerly) beach mining.

Today, the south shore of Lake Erie is severely sand-starved compared with conditions that existed 200 years ago. The lack of available sediment is largely due to man-made causes. As the shore developed and became urbanized after the mid-1800s, residents, industries, and municipalities attempted to arrest bluff erosion with the use of structures and vegetation. Now the U.S. shoreline of Lake Erie is almost 83% protected, a larger percentage than any ocean coast except in urban areas. It means that little sediment exchange occurs compared with predeveloped conditions, which, in turn, means that managers must recycle and reuse existing sediment to maintain recreation beaches. Managing sediment to benefit a region sustainably potentially will save money, allow use of natural processes to solve engineering problems, and improve recreation resources and natural habitat.

Cet article est une évaluation des sources et puits de sédiments, des phénomènes physiques et du transport de sédiment le long des côtes ouest et sud du lac Érié. L'objectif est de décrire les conditions environnantes actuelles pour les projets de mise en valeur des matériaux de dragage et ainsi faciliter l'implémentation des principes de Gestion Régional des Sédiments (RSM) lors de projets et études.

Information et données provenant d'une multitude d'articles scientifiques et de littératures techniques sont synthétisées et présentées en vue de la préparation d'un budget sédimentaire.

La berge américaine du lac Érié possède 28 embouchures de rivières et ports protégés par des brise-lames ou autre structures. Seize d'entre eux sont des projets de navigation sous le gouvernement fédéral.

Depuis la deuxième moitié du 19e siècle, la gestion des sédiments marin a surtout constitué à rendre les voies navigables sécuritaires, à maintenir la profondeur des canaux de navigation et à disposer des matériaux de dragage.

Les sédiments côtier proviennent de plusieurs sources, notamment des rivières (particules fines surtout), de rejet industriel (cendre et débris), des drains fluviaux, de l'érosion des escarpements de till (gravier, sable, argile) et des bancs d'argile, de l'altération des affleurements rocheux (surtout du shale), et finalement, en moindre importance, de l'érosion des sédiments et des affleurements rocheux situé au fond du lac. Les pertes de sédiments surviennent lors de leur transport en eaux profond

Recent research has highlighted the importance of soil biota in the establishment success of target plant species in restorations. This has led to restoration efforts that include soil amendments containing mycorrhizal fungi as well as other soil organisms. Although several studies have demonstrated interactions between plant species and soil biota, few studies have looked at interactions between plant variety and soil biota, particularly in the context of restoration. When several sources of plant material are available to land managers, it may be important to account for interactions between plant variety and soil inoculum. Here we present results from an experiment examining interactions between plant variety and soil inoculum for beach restoration. At two lakeshore beaches in Chicago, IL, we planted two varieties of the native beach grass Ammophila breviligulata, a common plant used in beach restoration. We included a soil inoculum treatment for half of the plots, using soil from nearby mature plant communities. The “Cape” variety of Ammophila had double the survivorship and growth of the regional variety of Ammophila “Vans.” Soil inoculum significantly increased survivorship and growth of the regional variety in one site, but not of the “Cape” variety. Mycorrhizal spore abundance and diversity, as well as plant root colonization, did not differ between treatments, indicating that some other soil organisms may be providing benefits to plants in this study. Our work shows that performance of key species for beach restoration can vary up to 300% depending on complex interactions between soil biota and plant variety.

Beach erosion problems have become prevalent in Korea as a result of its economic growth and coastal development. This paper summarizes a comprehensive approach used to mitigate beach erosion that occurred after the construction of a coastal road with a seawall along Namae Beach in Korea. Field measurements of waves and currents were performed to identify the wave-induced current pattern associated with the observed shoreline erosion in front of the seawall. The construction of a short jetty and two submerged reef mounds was proposed to reduce the wave-induced current and resulting beach erosion. After the jetty construction from May to August, 2008, the shoreline advanced offshore continuously in the zone affected by the jetty. Field monitoring will be continued during the reef mound construction and for beach nourishment proposed to maintain a wide beach in front of the seawall. This mitigation project indicates that the effect of a coastal road on an adjacent beach should be taken into account before its siting because of the long-term evolution of the beach morphology.

Daily flow data from four central wastewater treatment systems in coastal North Carolina were examined for responses to rainfall, tide level, and other environmental variables during the period January 2005 through December 2008. Flow data revealed substantial variation at several timescales, indicating external effects on flow volumes, most likely through inflow and infiltration (I&I). Daily flow volumes were strongly influenced by short-term rainfall quantities, as expected, but other factors contribute on a longer-term basis. The portion of total flow attributable to I&I varied from <10% to >100% of base flow. Multiple regression analysis showed that infiltration, defined in this analysis as flow responses to rainfall integrated over 3 day or longer periods, contributed the majority of increased flow. Significant infiltration effects indicate that collection systems are leaky and that elevated groundwater levels drive increased influent flows through central treatment systems. Sea-level variations also drove significant responses of influent flows. Increases in groundwater levels, whether from heavy rainfall or from increases in sea level, thus pose three threats to coastal sewer infrastructure: (1) reduction in treatment efficiency with higher flow volumes, (2) increased risk of bypasses as flow capacity is exceeded, and (3) introduction of saline water into treatment systems, with possibly negative consequences for the mechanical and biological integrity of these systems and higher operating and maintenance costs. Heavy rainfalls from coastal storms and higher than normal seawater levels from flooding tides would periodically increase the hazards from rising average sea levels. We recommend that additional studies be undertaken to assess saltwater infiltration into collection systems and that coastal municipalities monitor the integrity of their system components in relation to the threats posed.

The humped-back relationship in species diversity during succession was tested using vegetation in a coastal sand dune system of the German Wadden Sea island of Spiekeroog. Permanent plots were studied over 15 years along a spatial chronosequence from young grey dunes to old brown dunes. Species diversity, succession rate, and environmental indicator value were used to evaluate multitemporal dynamics of the ecosystem. Long-term development of the dune vegetation was reflected along the chronosequence, whereas fluctuations of plant communities were analyzed by short-term changes of each permanent plot.

The study confirmed the intermediate stress theory, whereas highest species diversity was reached at the transition zone of the environmental gradients. Total species richness showed humped-back relations along the xerosere. Hotspots in species diversity varied with the life form group. Highest richness of herbaceous plants was reached in semidynamic young grey dunes, whereas highest richness of bryophytes and lichens shifted due to competition effects to the driest parts of the dune gradient in older successional stages.

Moreover, the study confirmed the biodiversity-stability theory, with highest ecosystem stability at highest diversity. More stable environments showed lower succession rates than dynamic, disturbed environments. Thus, during secondary succession with probably repeated disturbance, the succession rate was higher and no clear direction of vegetation development was found in comparison to primary succession. The succession rate in a primary series represented a unimodal relation with total species richness. Thus, species-poor vegetation often dominated by one species, such as heathlands, as well as species-rich vegetation, showed lowest succession rates. These communities probably are more stable due to a balanced species combination represented by higher evenness.

Biogeochemical couplings between land and coastal waters are increasingly altered by land cover changes forced by accumulation of human uses of watersheds. In particular, human activities increase nitrogen loads to receiving waters. Definitions of forcings require estimation of external nitrogen sources and evaluation of the effects on the roles of different land covers, retention within watersheds, and net exports to the sea. One powerful example of change in N loads is the effect of urban development on the watershed and concentrations of inorganic nitrogen in the water of Great South Bay (GSB), New York. We defined land uses, delimited subwatersheds emptying into GSB, and estimated nitrogen loads to subwatersheds and from these to receiving waters. Wastewater-derived nitrogen was the dominant source to watershed surfaces (55%), with lesser amounts added by atmospheric deposition to land (31%) and fertilizer use (15%). About 77% of nitrogen entering the watershed was retained within the watershed, so that despite land use changes, the watershed furnished a substantial water quality subsidy, preventing enrichment of GSB. This high within-watershed retention is similar to rates observed elsewhere and was to a significant degree linked to areas of natural vegetation. About 50% of total nitrogen that entered GSB was of wastewater origin; only 16% was contributed by atmospheric deposition on land, 26% by direct atmospheric deposition on GSB, and 7% by use of fertilizer on land. In addition, the direct atmospheric deposition onto GSB amounted to 44% of the land-derived load, within ranges affecting other estuaries.

GSB is low on the range of eutrophication of estuaries. Within-watershed retention is still high, but land cover changes manage to force enough throughput of land-derived nitrogen—particularly wastewater nitrogen—to enrich coastal receiving waters. As land cover further shifts away from natural vegetation, eutrophication of GSB, and coastal receiving waters in general, will increase.

The wave absorption performance of a new type of steel floating breakwater with truss (FBT), which is composed of a box-type pontoon and truss structures, has been investigated experimentally. The truss structures are attached to the front and the rear of the pontoon, and exaggerate wave energy dissipation due to wave breaking. Flow visualization has revealed that the front truss breaks the incident waves and effectively converts wave energy to turbulent energy. Image analysis of the motions of the FBT and determination of the transmission coefficient K_t showed efficient dissipation of wave energy resulting from the truss structure. K_t is also discussed and quantified with the aid of dimensional analysis. Values of K_t are plotted against the ratio of the water depth h to the wavelength of incident waves L, and the profiles obtained are normalized by introducing values of h/L at which K_t equals 0.5, i.e., (h/L)_0.5. Normalization gives a universal empirical expression for K_t, and empirical expressions of (h/L)_0.5 are also obtained by independently changing the shape parameters and the wave steepness. A graphic chart of (h/L)_0.5 is provided so K_t of the FBT can be evaluated easily. This data-reduction method developed for the quantification of K_t may be applicable for other floating breakwaters as well as for this new type.

This study examines changes in shoreline change trends at Grand Isle, Louisiana, in relation to the implementation of a detached breakwater field completed in 1999. Eight sets of aerial photographs and digital orthophoto quarter quadrangle mosaics ranging from 1973 to 2004 were analyzed to establish pre- and postconstruction shoreline trends. Preconstruction, the island experienced persistent growth at its downdrift end. Postconstruction, this accretion ceased, and the downdrift end of the island began to experience erosion. The area landward of the breakwater field was accretionary before construction and became stable, whereas accretion increased in the area immediately updrift of the breakwater field. Two key design parameters, breakwater length and distance from the shoreline, were used to assess the potential for the formation of salients. Results from an engineering model suggest that the breakwaters were constructed too far offshore for this typical response to occur. Nonetheless, results of the air photo analysis indicate a marked change in shoreline migration trends following construction of the breakwater field.

(1) Simulations of wave action and erosion, using a wave-producing device and a recirculating flume, were established on the Haigang mudflat, in the Yellow River estuary, China, along with the geotechnical-parameter tests of the water content, bulk density, undrained shear strength, penetration strength, and grain-size distribution. Moreover, the variety of seabed morphological characteristics under different wave actions was also observed in field. The experimental results showed that the erodibility of the silty sediment was significantly affected by the cyclic wave loading in Yellow River estuary. The erodibility varied with the changing wave loading and was closely related to the liquefaction and topography characteristics of the surficial sediment, which restricted the physical and mechanical properties of the sediment. Additionally, the wave loading transformed the sediment components and the size grading, which also had a remarkable effect on the erodibility. Increasing the length of the time vibration during wave loading clearly reduced erosion resistivity, although fluctuations appeared in the overall downward trend, consistent with the strength indexes of the silty sediment.

The other geotechnical parameters, size grading, and sediment components show the wave's dynamic variation with the changing conditions, but no clear internal relationship could be found between the varying physical parameters and the variation in erosion during the changing conditions of the wave during the experiments.

El Niño events elevate water levels, change wave direction and storm frequency, and provide an analogy to the likely impacts of climate change. Elevated sea levels intensify coastal erosion impacts affecting not only oceanfront property and recreational users, but also habitats and species that depend on the coast. This study examines physical and ecological responses to and recovery from the extreme 1997–98 El Niño along beaches of Isla Vista, California, a stretch of coastline dominated by unidirectional alongshore sediment transport.

Using topographic light detection and ranging (LIDAR), physical measurements, and biological surveys we quantify physical changes and assess ecological responses. We quantify short-term reductions in beach widths (>60%) and sand volumes (∼80%). Although dune-backed beaches lost greater sand volumes, bluff-backed shorelines lost greater percentages of beach width. Four erosion hot spots were identified consistent with a pattern of beach reorientations.

Macrophyte wrack abundance, a primary food for sandy beach ecosystems, was significantly correlated with dry sand beach width. Macroinvertebrate biomass was reduced and a decline in mean size of individuals persisted for several species. Abundance and species richness of shorebirds were lower during the El Niño.

Beach segments and reorientations recovered at different times, on the basis of littoral drift direction, shoreline orientation, and wave exposure. The reorientation at the updrift beach impounded sand for >3 years after the El Niño, catalysing an erosion wave that propagated downdrift affecting downcoast beaches. Recovery of the updrift beach led to the widest beach widths shown in the historic record, whereas the downdrift beach underwent continued erosion >6 years after the El Niño. Recovery of wrack abundance and shorebirds to pre-El Niño levels took >3 years. Reductions in biomass and mean size of invertebrates were detected 2 years after the event. Recovery time lines provide information for coastal managers evaluating impacts and timing of erosion mitigation alternatives.

The pollen record in a sediment core from Manzala lagoon on the Nile delta coastal margin of Egypt, deposited from ca. AD 1860 to 1990, indicates rapid coastal wetland vegetation responses to two primary periods of human activity. These are associated with artificially altered Nile hydrologic regimes in proximal areas and distal sectors located to ∼1200 km south of Manzala. Freshwater wetland plants that were dominant, such as Typha and Phragmites, decreased rapidly, whereas in the early 1900s, brackish water wetland species (e.g., Amaranthaceae) increased. This change occurred after closure of the Aswan Low Dam in 1902. The second major modification in the pollen record occurred in the early 1970s, after Aswan High Dam closure from 1965 to 1970, when Typha pollen abundance increased rapidly. Massive population growth occurred along the Nile during the 130 years represented by the core section. During this time, the total volume of lagoon water decreased because of conversion of wetland areas to agricultural land, and input of organic-rich sediment, sewage (municipal, agricultural, industrial), and fertilizer in Manzala lagoon increased markedly. Although the wetland plant community has continued to respond to increasingly intensified and varied human-induced pressures in proximal sectors, the two most marked changes in Manzala pollen best correlate with distal events (i.e., closure of the two dams at Aswan). The study also shows that the two major vegetation changes in Manzala lagoon each occurred less than 10 years after closure upriver of the Low and High dams that markedly altered the Nile regime from Upper Egypt to the coast.

The variability and trends of storminess and extreme storm sequences on the Perth metropolitan coast are documented based on an extensive analysis of wave, wind, air pressure and water level observations for the period 1994–2008. By using the same statistical criteria for storm identification from different datasets, the storminess index across four datasets was compared. A preliminary examination of the nine most commonly used storminess indices reveals the level of interconnections among these indices. Strong correlation was found between annual total storm wave power and annual total storm wind hours. However, the correlation between annual storm indices determined by Fremantle nontidal residual water level and annual storm indices determined by Rottnest total wave heights was weak. Thus, it is not appropriate to use water level storminess index as a proxy to extend the relatively short wave records. The objective ranking of annual storminess by different data types and indices offers coastal engineers the statistical background for the selection of representative years and extreme storm sequences. No evidence of increasing (or decreasing) trends in extreme storm power was identified to validate the wave climate change hypotheses for the Perth region.

Artists of the XVII Provinces contributed considerably to cartography. For instance, Peter Pourbus, a Bruges painter, is the author of maps of Zeeland and of the Zwin Region, an area that Emperor Charles V (1500–1577) was anxious to protect against a seaborne enemy invasion. The coastal areas of Flanders and Zeeland were repeatedly covered, in prehistoric, protohistoric, and historic times, by the North Sea waters. The storm of the 13th century broke through continental barriers, opening a channel whose draught allowed ships to sail up to such towns as Sluis, Damme, and Hoek, sites that became, for several centuries, outer harbors of Bruges. The trade thus generated is at the origin of Bruges's wealth, leading to the Zwin inlet being nicknamed the “Golden Inlet.” Sadly, silting set in and occlusion of the inlet progressed inexorably. This benefited Antwerp, which took up the declining trade of Bruges. The richest city of northwestern Europe yielded thus to a sister city that would be, for several centuries, the largest city of the world. The Zwin inlet is today just a natural swimming pool. And at high tide a rivulet of water allows some canoes to manœuver. On the other hand, the region became a world-celebrated bird and plant natural refuge. Yet Bruges, like the phoenix reemerged from ashes, is again a ranking port, thanks to sea canals linking it to the sea and an artificial harbor (Zeebrugge) some 20 km south of the Zwin inlet's mouth, in full expansion. On the shoreline, erosion and sedimentation have brought about new modifications, some of which impact faunal presence, while others might trigger a political “tempest in a teapot.”

Analyses of land area and population distribution in the Low Elevation Coastal Zone (LECZ) and their potential susceptibility to future sea level rise have been used to derive first-order assessments of areas and populations at risk. Variations in results are shown to be highly dependent on the input datasets. In this paper we explore differences in land and population distribution estimates in the LECZ resulting from the use of three digital elevation models and two population datasets at global, continent, and country levels.

Results at the global scale show differences of up to 150% in area estimates, depending on the elevation model used. The differences are most extreme below 1 m elevation and diminish at higher elevation increments. On the continent level, the use of different elevation models produced area estimate differences ranging from more than 1200% at an elevation of 1 m to 160% in the LECZ. Country-level differences are even higher. Similarly, substantial differences in population distribution can arise with the use of different population datasets. Population counts below 1 m elevation range from 1% to 2.3% of the total global population. In the LECZ, estimates vary from 9.2% to 10.9% of the total global population. Differences at continental and country levels are also significant depending on the elevation model and the population dataset used. These large differences indicate that results of such analyses should be regarded with caution and within the context of the methods and materials used.

This paper presents a detailed study of a beach nourishment project in Beidaihe, China. The study consists of a detailed assessment of a small-scale trial project that was carried out during May to June in 2008 to create two bathing sites on West Beach and a numerical evaluation of scheme options for the full project involving beach nourishment, groins, and submerged breakwaters. The monitoring data indicate that the nourished beach in the small-scale project was slowly eroding but in February of the following year the beach was still 20 m wider than it was before the project. The long-term shoreline evolution was then predicted using the generalized model for simulating shoreline change, which was calibrated to reproduce the posttrial project shoreline. The model indicates that without follow-up nourishment, the nourished beach created by the trial project will cease to be suitable for bathing in just 2–3 years. As to the full project the numerical evaluation of various scheme options indicates that the east groin plays a key role in protecting the beach in the long term and the removal of a rock jetty at east end of the beach in 2002 is identified as one of the major causes for the present severe erosion of West Beach. On the basis of the simulation results an optimum scheme for the project is proposed.

A recent article published in the Journal of Coastal Research analysed a number of different sea-level records and reported that they found no acceleration of sea-level rise. We show that this is due to their focusing on records that are either too short or only regional in character, and on their specific focus on acceleration since the year 1930, which represents a unique minimum in the acceleration curve. We find that global sea-level rise is accelerating in a way strongly correlated with global temperature. This correlation also explains the acceleration minimum for time periods starting around 1930; it is due to the mid-twentieth-century plateau in global temperature.