Policy development is a dynamic and cyclic process characterised by successive stages of development, implementation and evaluation. Throughout this process, interaction between science and coastal management plays an important role. An illustration is given in this paper, based on an analysis of the history of coastal policy in the Netherlands over the last two decades. Evaluation in 1995 of the coastal policy of Dynamic Preservation, developed during the late 80's and implemented in 1990, led to a redefinition in 2000. Implementation in 2001, of a sustainable coastal policy in the Netherlands with both a small- and a large-scale approach, is the result.

The analysis in this paper indicates that the successful development and implementation of coastal policy in the Netherlands, is related to the use of a systematic ‘frame of reference’; characteristics are explicit definitions of both strategic and operational objectives applied in a 4-step decision recipe of (1) a quantitative state concept, (2) a bench marking procedure, (3) a procedure for CZM measures or intervention and (4) an evaluation procedure. Applications of this frame of reference show its high potential to better integrate coastal science and coastal policy and -management and to stimulate co-operation.

Electromagnetic profiling and groundwater sampling on Sugarloaf Key and Little Torch Key in the Lower Keys of Florida show that these small, low-lying islands support only brackish-water lenses. On both islands, the lenses have central cores with lower salinities surrounded by areas of increasing salinity. The uppermost few meters of these central zones are uniform and slightly brackish (∼3 ppt) year-round on Sugarloaf Key. On Little Torch Key, which is smaller, there is a similar central, uniform brackish zone during the wet season, with salinity slightly higher than on Sugarloaf Key. These lenses are similar in form to many freshwater lenses, except that the central zone is slightly brackish rather than fresh.

During the dry season Little Torch Key loses the central brackish zone, and salinities increase approximately linearly with depth. This dry-season pattern, in which the freshwater/saltwater mixing zone effectively extends throughout the lens, is similar to that documented on Enjebi Island on the Enewetak Atoll. Seasonal variations on Little Torch Key are less evident outside the central zone.

The central lower-salinity core on Sugarloaf Key coincides with elevations > 0.8 m. Using vegetation as a proxy for elevation, the central zone corresponds to the highest elevations on Little Torch Key as well. Tidal efficiencies on Sugarloaf Key indicate the tidal signal propagates through the high-permeability, buried Key Largo Limestone, and then upward through the overlying lower permeability Miami Limestone that contain the lenses. Mixing driven by tidal pumping is likely responsible for the absence of true freshwater lenses on these islands.

The Volga Delta developed in the closed Caspian basin can be classified as a river-dominated type. The subaqueous part of the delta (avandelta) is characterized by an extremely gentle slope and may be subdivided into shallow and deep parts. The very low-angle slope of the shallow avandelta is a major factor to mitigate impacts of Caspian sealevel (CSL) changes on the Volga Delta during the last 100 years.

The CSL has fluctuated 3.46 m in the last 100 years, with a high of −25.55 m relative to the Baku Datum (BD) in 1903 and a low of −29.01 m BD in 1977. Sea-level changes can be grouped into three stages: (1) slowly falling at an average rate of 1.1 cm yr⁻¹ in 1900–1929; (2) rapidly falling at an average rate of 6.3 cm yr⁻¹ in 1930–1977; (3) rapidly rising at an average rate of 8.8 cm yr⁻¹ in 1978–1999. During the rapid fall stage of sea level, the Volga delta-plain expanded at a rate of 2.3 km² yr⁻¹ to 180 km² yr⁻¹ because of alluvial accumulation and exposure of the shallow avandelta. Flourishing subaqueous vegetation promotes this expansion by trapping suspended sediments on the avan-delta.

The shallow avandelta is primarily covered by freshwater and its geomorphic and sedimentary features are controlled more by the river flow than by the CSL changes, waves or wind-induced currents. The shallow avandelta decelerated delta progradation during sea-level fall and delayed delta retreat during sea-level rise. Significant changes in the delta-plain area have not occurred in the rapid CSL rise stage. Moreover, the distributaries and their distal underwater channels underwent erosion by the river flow at least until the end of the last century. The CSL has risen with an average annual rate of 8.8 cm during the last 20 years, yet coastal erosion, coastal flooding, wetland loss and saltwater intrusion, observed in other deltas, have not occurred here. This may have resulted from the existence of the shallow avandelta and show that the world's deltas respond to sea-level rise in different ways.

Tidal inlet morphology is strongly dependent on local hydrodynamic conditions that rely on wave/tide dominance. In some places, this hydrodynamic context exhibits a very strong seasonal pattern, showing tide-induced morphologies in summer and wave-induced ones in winter. The Barra Nova tidal inlet in Algarve, South Portugal, presents such characteristics. Short term morphological changes were investigated during an extensive field campaign carried on in February and March 1999, after the winter storm period. This study integrates both topo-bathymetric surveys and remotely sensed video data in order to assess the morphological evolution of the inlet system during the transitional period following storms. Comparison of datasets issued from these two direct and indirect methods has shown a very good agreement (errors usually less than 10 cm in elevation) that allows the quantification of morphological changes of the entire inlet system during the whole period of video observation.

During a transitional period after winter storms, ebb shoals adjust rapidly to the new low wave energy conditions. They migrate eastwards (50 m in two weeks for the main sand bar of the downdrift swash platform), resulting in a global downdrift trending of the whole delta. This evolution, closely linked to the previous development of storm-induced features, tends to close the system. Despite a large retreat of Barreta Island during the storm event before the campaign, simultaneous downdrift migration of the inlet channel was not observed. Our results suggest that such a migration can occur only at the end of the transitional phase once the storm induced morphologies have been destroyed.

Concern is growing in France about climate change and the related issue of accelerated sea-level rise (ASLR). Although a national vulnerability assessment has not been produced, available information is sufficient to clearly identify the coastal zones which are at risk. On the Mediterranean coast, the most vulnerable area corresponds to the deltaic plain of the Rhône River, chiefly because of human actions (e.g., shortage of sediment supply as a result of dam construction; river embankments). Coastal erosion, lowland flooding, and ground water salinisation are the main impacts expected from ASLR. The Languedoc coastal barriers will move landward faster than at present, thus jeopardising dense tourist facilities. On the Atlantic coast, enhanced erosion of the Aquitaine sandy beaches is expected. Existing salt marshes do not appear threatened because mud sedimentation from soil erosion is active, but reclaimed areas will be at risk of flooding. Moderate salt intrusion is expected into the Loire estuary. The Normandy chalk cliffs may not recede faster than at present. Existing laws and regulations dealing with coastal management are sufficient to address the potential impacts which may affect populations and economic activities in the forthcoming decades as sea level rises.

The vertical accretion of salt marshes is mainly due to flow reduction and wave damping by vegetation. However, the details of the hydrodynamics are only partially understood, and have been studied mainly in the laboratory. This study presents detailed field investigations of the water flow in a Spartina maritima salt-marsh in the Ria Formosa, a shallow, meso-tidal lagoon in Southern Portugal. Detailed velocity profiles were obtained within and above the 30 cm high canopy using a high-precision velocimeter. Results show that the influence of the bottom becomes negligible a few centimetres above the bed, and that the flow depends on the vegetation density at each level of the canopy. When the canopy is partially emergent or is only slightly submerged, the upward increase of horizontal velocity is roughly linear. A more drastic flow reduction exists when the canopy is well submerged, with a slow, nearly constant velocity in the denser part of the canopy and a faster, logarithmic shaped velocity profile above. This dampening effect of the vegetation is expected to promote sedimentation. However, the short-term sedimentation rate obtained with sediment traps during fair-weather conditions is usually lower in the Spartina marsh than in the surrounding areas. Therefore, the effect of the Spartina canopy for sediment accumulation seems to be more that of erosion protection during storms than of sedimentation enhancement during normal conditions. Using these results, a simple conceptual model is proposed for the sedimentary processes taking place in the intertidal areas of the studied lagoon.

The fine grained carbonate mud sediments of central Florida Bay are resuspended quite easily. However, this disturbance is usually limited to the surficial (‘floc’) layer, as the underlying sediments appear to be stabilized by an hydrogelation involving the bulk organic matter. That gelation has occurred within these sediments is suggested from their physical behavior and an observed mathematical relationship between the percentages of organic carbon (C_org) and water. Specifically, when extruded from a core barrel, the sediment maintains its integrity and has the consistency of a fine spackling compound. However, upon homogenization, as with a stirring rod prior to sieving, these sediments break into two distinct phases, ½–⅔ milky water and ⅓–½ sediment grains, by volume. The relationship observed between C_org and water was modeled as both linear (% water = (0.0777) C_org 0.2984, R² = 0.8664) and logarithmic (% water = 0.2489 L_n C_org 0.2842, R² = 0.9455) functions. As this relationship tends to be asymptotic at higher C_org (>3.5%_dry)/water values (>60%) and given an higher correlation, the relationship appears better modeled as a logarithmic function. Values of C_org from 1.2 to over 6.5%_{dry wt.} and water contents from 30 to over 70%_wt. were observed. The calculated intercept revealed that, without organic carbon (viz. hydrogel formation), these carbonates would likely contain only ∼30% water by weight (‘m’ from linear model).

This gelation is proposed to involve exopolymeric substances (EPS), likely polysaccharides, derived from diatoms and cyanobacteria of the microphytobenthos. A cyanobacterial-diatomaceous biofilm/mat underlain by purple sulfur bacteria was shown, by pigment based chemotaxonomy, to form the main components of the microphytobenthos. Additional water column detrital biomass, also mainly cyanobacteria and diatoms, is admixed with the living micro-phytobenthos in a flocculent/nephloid layer above the sediments prior to final incorporation into the gel-stabilized sediment column. Loss of seagrass cover appears to have allowed higher energy wave induced effects to reach the water-(nephloid)-sediment interface and increase overall turbidity in the bay.

The effects of these gelatinized organics upon sediment stability, pore water chemistry and dissolved species flux in/out of the sediments are discussed as areas for future research which takes this (hydro-) gelation phenomenon into account.

There are no previously published granulometric studies of the sediments from the coastal areas of the UAE. In this study one hundred and forty-four beach sediment samples were collected from coastal districts of seven emirates (Abu Dhabi, Dubai, Sharjah, Ajman, Umm Al-Quwain, Ras Al-Khaimah and Fujairah) for the purposes of grain size analysis and province delineation. A range of grain size data analysis methods, such as bivariate scatter plots and discrimination functions, were employed in the interpretation of the environments and mechanisms of sediment deposition. Multivariate statistical analysis was also used to discriminate between different coastal zones.

The Arabian Gulf coast can be divided into the following three provinces: a) Abu Dhabi/Dubai province, b) Sharjah/Ajman/Umm Al-Quwain province and c) Ras Al-Khaimah province. The Gulf of Oman coast can be divided into the following four provinces: a) Rol Diba Province, b) Dadnah/Aqqa province, c) Khor Fakkan province and d) Fujairah province. The results from this study suggest that the variations between different sites may be due to either the diversity of the sources of the sediments, or to the geomorphology of the coastal area. The second factor has controlled the details of transport of sediments along the coastal areas. Another important variable is the geology of the coastal strip that affects the types and distributions of coastal sediments.

Three late Quaternary stratigraphic units are present in the macrotidal-flat deposit in Namyang Bay, west coast of Korea: a mid-to-late Holocene greenish gray sand/mud deposit (unit M1), an early Holocene reddish brown clay deposit (unit T1), and a late Pleistocene yellowish, semi-consolidated mud deposit (unit M2), in descending order. Unit M1, representing a Holocene intertidal-flat deposit, shows a coarsening-upward trend in texture, which is resulted from the continual retrogradation of the tidal flat during the mid-to-late Holocene sea-level rise. This retrogradational coarsening-upward succession, elucidating a reverse trend to the progradational fining-upward facies model generalized for tidal flats worldwide, may be attributable to a very low accumulation rate (< 1 mm/yr) in this sediment-barren coastal setting. Reddish brown-colored unit T1, clearly separated from overlying unit M1 by a sharp lithologic boundary, consists of homogeneous clay with abundant freshwater siderite grains. Radiocarbon age, siderite grains, and lithologic features indicate that unit T1 is the early Holocene deposit in freshwater bog or swamp, infilling topographic lows. Overlain unconformably by the early Holocene clay deposit, unit M2 is characterized by dewatered, oxidized mud, which is interpreted as being the late Pleistocene tidal deposit that was subaerially exposed during the sea-level lowstand, possibly LGM. The unconformity between units M2 and T1 is probably related to the latest Pleistocene or earliest Holocene sea-level lowstand.

Bahía Blanca Estuary is a complex network of tidal channels, extensive tidal flats, low marshes areas and islands. The lack of a large source of sediments either from river or the shelf results in that the tidal channels of this estuary controlling the dispersal of sediment into the system. A 3-year study of morphodynamic equilibrium has been carried out in the tidal channels of Bahía Blanca Estuary with the aim to investigate the evolution of the system. Detailed changes in the spatial bathymetry linked to the observed flow and sediment processes give a clearer indication of the tidal circulation in the channels. This paper discusses morphologic variability and processes of the erosion, deposition and transport of sediment, which determines the morphological evolution of the system.

Current measurements showed that channels appeared to be ebb-dominated with peak speeds of up to 1.2 m/s. Examination of current durations suggests that flood-time dominance is about 7 hr, while ebb period is 5 hr. The cross section bathymetry is usually bimodal with two channels separated by a shallow area. The deeper channel experiences ebb-directed net, while the shallower channel could be influenced by the net flood current. The net sediment transport into of these systems is shown to be governed more by the degree of tidal velocity asymmetry (ebb flow). In change the degree of time asymmetry (flood flow) governs the trends of erosion by the longer duration of tidal flood.

Channel migration causes a shift from degradation in the north sector to aggradation in the south side, during adjustment. As a consequence, the estimated rate of migration is on the order of 25 m yr⁻¹.

Comparing the migration pattern between tidal and fluvial channel, we can to say that in rivers, where the water flows only one way, all morphologic features tend to migrate downstream. In tidal channels, by contrast, the erosive features appear to migrate in opposed directions to the dominant sediment transport direction. It is the erosive processes at tidal channels, which are mainly associated with flood currents dominance.

In order to reap the potential of airborne lidar surveys to provide geological information useful in understanding coastal sedimentary processes acting on various time scales, a new set of analysis methods are needed. This paper presents a multi-temporal lidar analysis of north Assateague Island, Maryland, and demonstrates the calculation of lidar metrics that condense barrier island morphology and morphological change into attributed linear features that may be used to analyze trends in coastal evolution. The new methods proposed in this paper are also of significant practical value, because lidar metric analysis reduces large volumes of point elevations into linear features attributed with essential morphological variables that are ideally suited for inclusion in Geographic Information Systems.

A morphodynamic classification of north Assategue Island for a recent 10 month time period that is based on the recognition of simple patterns described by lidar change metrics is presented. Such morphodynamic classification reveals the relative magnitude and the fine scale alongshore variation in the importance of coastal changes over the study area during a defined time period. More generally, through the presentation of this morphodynamic classification of north Assateague Island, the value of lidar metrics in both examining large lidar data sets for coherent trends and in building hypotheses regarding processes driving barrier evolution is demonstrated.

Lake-level change and landslides are primary controls on the development of coastal environments along the coast of northeastern Lake Michigan. The late Quaternary geology of Sleeping Bear Dunes National Lakeshore was examined with high-resolution seismic reflection profiles, ground-penetrating radar (GPR), and boreholes. Based on sequence-stratigraphic principles, this study recognizes ten stratigraphic units and three major unconformities that were formed by late Pleistocene glaciation and postglacial lake-level changes. Locally high sediment supply, and reworking by two regressions and a transgression have produced a complex stratigraphy that is prone to episodic failure. In 1995, a large landslide deposited approximately 1 million m³ of sediment on the lake floor. The highly deformed landslide deposits, up to 18 m thick, extend 3–4 km offshore and unconformably overlie well-stratified glacial and lacustrine sediment. The landslide-prone bluff is underlain by channel-fill deposits that are oriented nearly perpendicular to the shoreline. The paleochannels are at least 10 m deep and 400 m wide and probably represent stream incision during a lake-level lowstand about 10.3 ka B.P. The channels filled with sediment during the subsequent transgression and lake-level highstand, which climaxed about 4.5 ka B.P. As lake level fell from the highstand, the formation of beach ridges and sand dunes sealed off the channel and isolated a small inland lake (Glen Lake), which lies 5 m above the level of Lake Michigan and may be a source of piped groundwater. Our hypothesis is that the paleochannels act as conduits for pore water flow, and thereby locally reduce soil strength and promote slope failure.

Twenty-six years of monthly beach profiles located along 3.6 km Narrabeen beach were analyzed using time series, principle components (PCA) and wavelet analysis. The time series reveal both beach oscillation (erosion-accretion) and rotation between the boundary headlands. The rotation phenomenon is confirmed by the 2nd PCA component, explaining 58% of the remaining data variance. The scale of beach oscillation is on the order of 70 m, with 30 m of this oscillation attributed to beach rotation. Continuous wavelet transform analysis identified decadal scale patterns in beach response. This analysis indicates that variability in ensemble beach width and beach rotation exhibit long-term non-stationary variability. Longer-term cycles of behavior in overall beach erosion/accretion and beach rotation appear to coincide with each other, while short term fluctuations suggest a variety of physical processes are responsible for beach width variation and the interannual rotation phenomenon.

Chronic erosion of beaches along the eastern Texas barrier island coast is increasingly mitigated by renourishment efforts that periodically place large volumes of sand onshore. Location of beach-quality sands on the inner continental shelf is challenged in an environment where terrestrial rivers deposit fluvial sediments in back bays and lagoons instead of offshore and by shelf areas that are dominated by muds. The search for beach-quality sands thus requires understanding of the coastal geological framework and morphodynamic processes that accompanied late Quaternary evolution in the northern Gulf of Mexico. The occurrence of surficial sand deposits as positive bathymetric features on the seafloor (ridges, shoals, banks) and presence of sands buried in paleovalley (drowned channels) infill sequences makes for complicated search procedures that must accurately differentiate a range of sedimentary settings by geophysical and geotechnical surveys. Compilation of vast amounts of data from historical core logs and newly acquired information in a marine information system (MIS) permits spatial analyses in a format that is compatible with development of a sand search model. The resulting differentiated investigative sand-search methods, that comprise part of the Texas Sand Search Model (TSSM), are able to target potential borrow areas in ebb-tidal shoals, low-relief ridge deposits, high-relief banks, and in mud-covered paleovalley sequences.

World-wide coastal zones are subject to physical and societal changes. Due to climate change sea level is expected to rise and storm conditions may become more intensive. Both may lead to shore erosion intensification in the coastal zone. Moreover, the coastal zone is intensely used for societal development. The pressure upon the coast increases. It may be questioned whether coastal defence is compatible with spatial development in the coastal zone. To guide the consequences of climate change and the societal developments in a responsible manner, spatial decisions have to be taken cautiously. A long-term coastal vision is important to ensure safety in the future and to gain as much profits from the economic opportunities offered by the coastal zone as possible.

This problem is resolved here by an economic optimisation method. Long-term coastal policies are economically assessed with a stochastic economic optimisation model. This model combines the hydraulic and morphological processes in the coastal system with the maintenance measures and the socioeconomic and ecological activities. The maintenance costs in relation to the possible damage resulting from coastal recession are optimised with the model. The model is influenced by various uncertainties, which affect the optimisation results. Therefore, uncertainty distributions have been assessed and Monte Carlo simulations are made with the model.

The model is applied to the Dutch coast. The expected minimal total costs of various coastal policies are estimated. Optimisation results show that coastal defence and societal activities in the coastal zone in the Netherlands are indeed compatible.

The variability of two lake gravel beaches (Loch Lomond, Scotland) is described in the context of changing environmental conditions. Waves, water levels and wind orientation and velocity were recorded for 1 year. The wave climate comprises small amplitude, high frequency, short-period waves and periods of calm (mean frequency = 0.92 secs; mean significant wave height = 0.08 m). Incident wind-wave direction was an important influence on beach morphology. Water levels fluctuate and there is a general increase in level. Wave activity combined with high water levels affects the upper beach and backshore although here, the highest waves were recorded at low water levels which minimised wave damage.

Cliff erosion rates were recorded. Beach morphological changes showed highly variable profile types which were closely related to beach elevation, exposure and sediment supply. Sections of beach represented by individual profile types showed re-occurring profile types and different sections of beach responded differently to similar conditions. Specific characteristics e.g. narrow beach form, steep foreshores, scarps, beach ridge formation and preservation were noted and a morphological classification for coarse clastic beach profile types was devised. Beach planform is complex and antecedent morphology can persist for some 10 years. Sediment movement is restricted to individual bays which behave as sediment cells. Recommendations for shore management plans which are closely linked to the geomorphological and sedimentological conditions at specific sites within the context of the whole shoreline are given. These have wider application for restricted-fetch coarse clastic beach sites.

This study deals with incorporating predictions of sea level rise into practical municipal planning. Predictions of global mean sea level rise can be made with more confidence than many other aspects of climate change science. The world has warmed in the past century, and as a result global mean sea level has risen and is expected to continue to rise. Even so, there are significant uncertainties regarding predictions of sea level. These arise from two main sources: the future amount of greenhouse gases in the atmosphere, and the ability of models to predict the impact of increasing concentrations of greenhouse gases.

Current knowledge regarding the effect of global warming on sea level rise is reviewed. Global mean sea level is expected to rise by 3–30 cm by 2040, and 9–88 cm by 2100. An important remaining uncertainty is the future contribution of surface water storage (for example, lakes and reservoirs) to changes in sea level. In addition, there are also significant local sea level effects that need to be taken account in many regions of the globe, including isostatic and tectonic effects. The thermal expansion component of sea level rise is also likely to vary regionally, due to regional differences in the rate of downward mixing of heat and to changes in ocean currents.

The current state of planning for sea level rise in Australia is reviewed. While not all coastal municipalities include sea level rise in their planning schemes, the recent adoption in a number of States of new planning schemes with statutory authority creates a changed planning environment for local government. Coastal urban planning needs to take sea level rise into account because its effects will be apparent during the typical replacement time of urban infrastructure such as buildings (before about 70 years). For local planning, ideally a risk assessment methodology may be employed to estimate the risk caused by sea level rise. In many locations, planning thresholds would also have to be considered in the light of possible changes in storm surge climatology due to changes in storm frequency and intensity, and (in some locations) changes to return periods of riverine flooding. In the medium term (decades), urban beaches will need beach re-nourishment and associated holding structures such as sea walls. Changes in storm and wave climatology are crucial factors for determining future coastal erosion.

This review paper provides a brief review on the development of ideas in the fields of the sea level change of the ECS (East China Sea), the history of the Yangtze River entering the sea and paleochannels in the shelf of the ECS since the Last Glacial Maximum (LGM). The paper summarizes two opposite theories about the Yangtze River entering the sea during the LGM. One theory is that the Yangtze River input a lacustrine in the north of Jiangsu province which was defunct in middle Holocene, and the river was once dry. The other was that the Yangtze River still existed and entered into the Okinawa Trough during the LGM, but scholars share different opinions on which course the river ran across and which place the river input the trough.

This paper concludes future work is to study the evolution of the Yangtze River and the paleoclimate and the corresponding events as a whole from the view of regional and even global change, and more attention should be paid to the study on mud sediment, the Yangtze River's response to the changes in climate and sea-level, and the channel metamorphosis.

The decrease in longshore sediment volumes from north to south, calculated for littoral cells between inlets, indicates significant loss from the littoral drift system along the Florida east coast or localized deposition. The decrease in littoral drift volume from about 490,000 m³ of sediment over a distance of about 550 km (average diminution rate of about 890 m³ km⁻¹) was traditionally accounted for in terms of alongshore deposition and some unknown degree of speculated offshore transport. With the application of laser airborne depth sounding (LADS) technology to bathymetric survey in southeast Florida (2001–2003), recognition of detailed bottom topography became possible for the first time. Significant in this regard was the bathymetric display of macro- and mesoscale morphological features that showed areal continuity of sandy bottoms and the prominent but disjunctive occurrence of relict barrier coral reef tracts that line the shelf edge. Identification of gaps in the line of barrier reefs showed pathways of cross-shore sediment transport from the inner shelf to offshore beyond the shelf edge. Diabathic sediment transport through these reef gaps robs the littoral sediment package by allowing the chuting of sediments during high energy events or when the backreef flats over fill with sand. The reef gaps are thus leaky valves where littoral sediments are periodically chuted offshore and lost from the littoral drift system.