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McNamara, G. and Vieira da Silva, G., 2023. The coastline paradox: A new perspective. Journal of Coastal Research, 39(1), 45–54. Charlotte (North Carolina), ISSN 0749-0208. The coastline paradox, which suggests that coastlines have indefinite lengths, is a widespread and misleading concept that has endured in scientific literature for over 50 years. This paper argues that the length of a coastline is real and finite. The measurement of coastlines allows for the quantification of coastline dynamics and engineering responses to these changes. The real difficulties in measuring sometimes complex coastal shapes have taken the appearance of an unreal impossibility. The paradox is resolved using three methods. The first examines definitions used to establish the features to which "coastline" refers. The second applies these definitions to the measurement of real coastlines. Finally, a geometrical analysis is carried out to resolve the paradox mathematically. The purpose of this paper is to help resolve the paradox and reduce confusion surrounding the topic, which will be of direct use for coastal communities and planners to assess and respond to coastline changes and sea-level rise. [ABSTRACT FROM AUTHOR]

Skinner, W.K., 2024. Coastal hazard assessment from multidecadal profile response incorporating climate patterns and sea-level rise. Journal of Coastal Research, 40(3), 511–526. Charlotte (North Carolina), ISSN 0749-0208. A new method for coastal hazard assessment is described and demonstrated by reference to a 40-year cross-shore profile record in Papamoa, New Zealand. It is based on a mathematical interpretation of the envelope within which long-term historic cross-shore profiles vary and from which, for the required assessment period, the statistically significant fully accreted-state and fully eroded-state profiles can be determined. The Monte Carlo method is used to derive stochastic outcomes for long-term trend (LTT) and sea-level rise (SLR) on the basis of correlations with, and a long term proxy for, a decadal-scale climate pattern, which in the example case is the Interdecadal Pacific Oscillation. Sediment volumes for short-term fluctuation and the LTT are determined and conserved to reflect a consistent wave climate over the assessment period when appraising the effect of SLR. Dune biomass is accounted for when determining erosion scarp stability and hence the final extent of the current and future hazard zones. Results are presented in schematic form as excursions relative to a land benchmark and also as full end-state profiles extending from the dune backshore to the closure depth, with the latter determined by bar volume and profile. Various scenarios are appraised, including those that incorporate SLR predictions of the climate models of the Intergovernmental Panel on Climate Change. The relative risk of various scenarios is benchmarked to the probalistic expected outcome to produce a risk-based, site-specific assessment of coastal hazards. [ABSTRACT FROM AUTHOR]

Basack, S.; Loganathan, M.K.; Goswami, G., and Khabbaz, H., 2022. Saltwater intrusion into coastal aquifers and associated risk management: Critical review and research directives. Journal of Coastal Research, 38(3), 654–672. Coconut Creek (Florida), ISSN 0749-0208. Coastal regions mainly rely on sources of local fresh groundwater for domestic, irrigational, and industrial usages, which are vulnerable to high-risk of getting intruded by saltwater. Excessive pumping of fresh groundwater initiates advances of saltwater-freshwater interface inward due to hydraulic equilibrium and continuity. This introduces saline water intrusion into coastal aquifers. This is also caused by natural hazards like sea-level rise and storm-surge. The saltwater intrusion in coastal aquifers contaminates the freshwater storage, thereby emerging as a major environmental issue. To incorporate adequate coastal groundwater control and management techniques that are effective and conveniently implementable, understanding the phenomenon of saline water intrusion and the risk assessment is of utmost importance. Several scientific contributions including theoretical (analytical and numerical) solutions, experimental (laboratory and field) results, design recommendations, and risk analysis are available, indicating remarkable advances in the research area. The authors have attempted to summarize the significant contributions over the last few decades in each of these study aspects through extensive literature survey and critical analysis of the existing knowledge. It is observed that risk prevention and control methodologies such as qanat-well structure, shallow and deep wells might not be effective in many coastal areas as the complex intrusion process is yet to be understood clearly. Moreover, the high intensity coastal hazards that often occur due to climate change continue to make aquifers more vulnerable, adversely affecting the coastal groundwater management. The paper presents a critical overview of existing studies on saline water intrusion into coastal aquifers and associated risks and management techniques. Furthermore, adequate research directives with recommendations for future development are also provided. [ABSTRACT FROM AUTHOR]

Patsch, K.; King, P.; Reineman, D.R.; Jenkins, S.; Steele, C.; Gaston, E., and Anderson, S., 2021. Beach sustainability assessment: The development and utility of an interdisciplinary approach to sandy beach monitoring. Journal of Coastal Research, 37(6), 1130–1157. Coconut Creek (Florida), ISSN 0749-0208. Sandy beaches are valued for various ecosystem services but are increasingly imperiled by anthropogenic stressors. Sea-level rise (SLR), reductions to sand supply, hardening the position of the coastline, and the prevalence of human development along California's coast combine to reduce the fundamental dynamism critical to the resilience of California's beaches. If California continues with business as usual, many of its beaches will erode and eventually disappear. Coastal jurisdictions in California are planning for SLR. However, these coastal managers lack a standardized regional assessment tool that compiles information on the current and likely future condition of sandy beaches. Without such a tool, these managers have limited ability to analyze the integrated impacts of historic decisions or future alternative management scenarios upon beach morphology, ecological functioning, economics, and social utility. This paper presents a study of the Beach Sustainability Assessment (BSA) decision support tool applied to 17 beaches spanning Santa Barbara, Ventura, and Los Angeles counties. In addition to scoring and grading geomorphological, ecological functioning, and social utility components, the BSA provides a single, overall grade for each beach. To demonstrate the utility of the BSA, a scenario with 1 m of SLR and a 100-year storm was simulated to assess the changes to the overall grade and component grades. The BSA offers a cost-effective, standardized protocol to monitor the condition of California's sandy beach ecosystems. The metrics support spatial and temporal comparisons on a regional scale, giving coastal managers and stakeholders the ability to assess real trade-offs among management solutions. Current BSA indices indicate that beaches in the Southern California Bight study area are already struggling, with most urban beaches receiving Cs and Ds for ecological functioning. The SLR stressor test indicates that ecological functioning and social utility will continue to decline with increasing sea levels. [ABSTRACT FROM AUTHOR]

Adaptation is defined as the planned or unplanned, reactive or anticipatory, successful or unsuccessful response of a system to a change in its environment. This paper examines the current status of adaptation to sea-level rise and climate change in the context of European coasts. Adaptation can greatly reduce the impact of sea-level rise (and other coastal changes), although it requires adjustment of coastal management policies to changing circumstances. Consequently, adaptation is a social, political, and economic process, rather than just a technical exercise, as it is often conceived. The Synthesis and Upscaling of sea-level Rise Vulnerability Assessment Studies project has shown that adaptation to sea-level rise is widely divergent among European countries. Crudely, four groups of countries were identified: 1. Those that do not worry about accelerated sea-level rise and should not as their coasts are not susceptible 2. Those that do not worry as they have more urgent problems 3. Those that do not worry but probably should 4. Those that do worry and have started to adapt At the European Union level, while coastal management is a focus, this effort is mainly targeted at today's problems. Hence, this paper suggests the need for a concerted effort to address adaptation in coastal zones across Europe. Sharing of experience among countries would facilitate this process. [ABSTRACT FROM AUTHOR]

This paper introduces the collection of papers on impacts of sea-level rise on a number of European countries, and presents some overarching conclusions. [ABSTRACT FROM AUTHOR]

Rate of global eustatic sea-level rise during the Holocene Epoch has been identified as the principle cause of observed changes or inferred evolution of nontectonic coastal systems in mid- to low-latitude areas. The rate of rise is now three times faster than it was for the past several thousand years and similar to values associated with the middle Holocene marine transgression. This acceleration can be attributed to human-caused global warming. In this investigation, the effects of accelerating sea-level rise on coastal sedimentary environments of the SE Saline Everglades were quantified. The results reveal historic changes to coastal habitat, sedimentation, and stratigraphy that are transgressive. These changes initiated during the early 20th century and are attributed to accelerating sea-level rise. As this acceleration and the resulting geologic record is a suspected consequence of human-induced global warming, the paper concludes with a discussion of the relevance of these observations, in tandem with others, to the current debate over the utility and use of the proposed Anthropocene. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Coastal Research is the property of KnowledgeWorks Global, Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The authors reflect on the definition and criteria of coastal counties to determine the percentage of the U.S. population who live in coastal areas. They compare the common definition of coastal counties (which includes watersheds along the coast and along the Great Lakes) with those of the Federal Emergency Management Agency (FEMA). According to the authors, FEMA normally uses 100-year floodplain and census block data to define coastal areas. He recommends this usage when dealing with sea level rise predictions.

This paper deals with the classification of the coasts of two Greek islands (Salamina and Elafonissos), according to the sensitivity to long-term sea-level rise by applying the Coastal Sensitivity Index (CSI). Salamina lies in the Saronic Gulf about 2 km off-coast from Piraeus (the port of Athens). The island has an area of 93.5 km2 while the total length of the coastline is 131.3 km. Elafonissos has an area of 19 km2 (coastline length: 30.4 km) and lies west of cape Maleas in the Lakonic Gulf (South-east Peloponnese). CSI calculation involves the physical variables of geomorphology, coastal slope, relative sea-level rise rate, shoreline change rate, mean tidal range and mean wave height, in a quantifiable manner. Every section of the coastline is assigned a risk ranking based on each variable, and the CSI is calculated as the square root of the product of the ranked variables divided by the total number of variables. CSI maps which were produced for the studied islands showed that Elafonissos is more susceptible to a future sea-level rise since an extensive length of its coast (16.7 km, corresponding to 54.5% of the entire coastline) is characterized as highly and very highly sensitive primarily due to the low topography and the presence of extensive sandy beaches. On the other hand only 2 km of Salaminas' shoreline, corresponding to 1.5% of the entire coast of the island, is of high sensitivity. Areas of high and very high CSI values host socio-economically important land uses (urban areas and recreational activities). [ABSTRACT FROM AUTHOR]

Chen, Y.; Huang, W., and Xu, S., 2014. Frequency analysis of extreme water levels in east and southeast coasts of China with analysis on effect of sea level rise. Qiantang bore as well as the storm surge are great disasters for river bank protection at the estuary of Qiantang River. Pearl River estuary is also frequently attacked by strong typhoon storm surge. The risk of damage from storm surge is expected to increase in both estuaries, exacerbated by sea level rise (SLR) and possible climate-induced increases in typhoon intensity and frequency. Adequate estimation on extreme water level will be essential to the coastal flood mitigation for both estuary areas with the effect of climate change. In this study, the popular frequency models Weibull, Lognormal, Gumbel, P-III and GEV are compared on Ganpu station located at the estuary of Qiantang River and Denglongshan station in Guangdong province, the optimal GEV model is recommended. For the risky analysis and management concern induced by the shortage of studied data, the estimated 50 year and 100 year extreme water levels respectively at Ganpu and Denglongshan stations are recommended in this study. Both studied stations located at different estuaries are all type II GEV model as the parameter of GEV distribution are higher than 0. The difference of the parameter and the reason causes the difference in the studied stations are analyzed and discussed in this paper. Furthermore, with the estimated 2.9mm/yr SLR by sea level bulletin of China, effect of SLR in frequency analysis on Denglongshan station is discussed. [ABSTRACT FROM AUTHOR]

Long, S.A.; Mango-Mutiti, C.; Mutiti, S., and Weese, D.A., 2023. Investigating the effects of increasing water salinity on an endemic crayfish. Journal of Coastal Research, 39(5), 816–822. Charlotte (North Carolina), ISSN 0749-0208. The greatest diversity of freshwater crayfish is found in the southeastern United States, home to nearly 75% of the world's known crayfish species. Many of the freshwater habitats for these crayfish are threatened by human activities and face degradation from multiple fronts, one being climate-related sea-level rise. This threat is significant for island populations that are unable to disperse to favorable locations. The goal of this study was to investigate the salinity tolerance of Procambarus lunzi (Hobbs 1940b), a species endemic to a small coastal region in the southeastern United States, to predict how sea-level rise might affect vulnerable coastal populations. A total of 171 crayfish was collected from a barrier island in Georgia and exposed to three treatments: freshwater, a slow salinity increase (salinity raised by 1.5‰ weekly), and a fast salinity increase (salinity raised by 3‰ weekly). Weekly mortalities were recorded and used to compute percent survivorship. Individual body masses were also monitored weekly and the average change in body mass between treatment groups was compared using one-way analysis of variance. Regression analysis was used to assess the relationship between initial body mass and the salinity level tolerated before mortality occurred. There was no significant difference in body mass change between the control group and the salinity treatment groups. The salinity level tolerated before mortality occurred was not correlated with individuals' body mass at the start of the treatments. The first mortality occurred at 30‰ salinity and 50% mortality occurred when salinity was >39‰. These results indicate a high tolerance to salinity that was unexpected for a freshwater species. The implication is that P. lunzi may be able to withstand habitat degradation due to sea-level rise given its relatively high tolerance to increases in salinity. [ABSTRACT FROM AUTHOR]

van Proosdij, D; Perrott, B and Carroll, K., 2013. Development and Application of a Geo-temporal Atlas for Climate Change Adaptation in Bay of Fundy Dykelands. Globally, dykelands (former marsh areas protected by dykes) are of strategic importance for climate change adaptation. Many were originally designed to protect agricultural land, yet now protect valuable infrastructure. The purpose of this project was to develop a comprehensive digital atlas incorporating historical plans, shore protection, coastal geomorphology and LiDAR to serve as a basis for climate change adaptation planning in the Bay of Fundy. 110 paper plans were scanned, geo-referenced and features such as current and historical dykes, aboiteaux (tide gates), armouring, ditches, creeks, property boundaries, foreshore marsh, and geodetic elevations were digitized using ArcGIS. Attributes included age of structure, material, dimensions, and ownership. Dyke elevations were surveyed using an RTK GPS, and individual sections were identified as being vulnerable to storm surge and sea level rise. Erosion rates and width of foreshore marsh were calculated per dyke segment. At present, 55% of dykes within Nova Scotia are within 0.5 m of critical elevations established in the 1960s, 2% are more than 0.5 m below critical and all are below the predicted rates of SLR by 2055. There is also a strong relationship between the placement of armouring along the dyke toe and foreshore erosion. Conversely, timely placement of armouring along the foreshore marsh decreased rates of erosion. This was most effective in areas with the largest fetch; less effective where erosion was driven by tidal currents. All data were integrated into ArcReader for use by Agriculture personnel and have been essential for cost effective climate change adaptation planning including dyke topping, hazard mitigation and education. [ABSTRACT FROM AUTHOR]

Foreshore (intertidal) narrowing and steepening have become increasingly discussed issues in coastal management. With rising sea levels they could be expected to lead to higher wave energies reaching the shore, thus enhancing rates of erosion. The present paper investigates changes in the position of the tide lines in Southeast England as measured from historic and modern maps. The changes can be partly explained by sea-level rise and shore platform erosion, but appear to be due mainly to systematic errors associated with the map sources. Comparison of the positional change of tide lines along the 170 km of chalk coast from East Sussex to the Isle of Thanet suggests that evidence for large-scale foreshore narrowing is meagre. The most likely scenario is one of parallel profile retreat resulting from natural processes such as relative sea-level rise. [ABSTRACT FROM AUTHOR]

Recent investigations of tide gauge and hydrographic data point to the conclusion that twentieth-century global sea-level rise was about 1.8 mm/y, with significant decadal and longer variability. Ocean thermal expansion can account for about 0.5 mm/y of the trend, leaving an additional ∼1.3 mm/y water equivalent that must have come from other sources. Greenland, Antarctica, and small glaciers are obvious candidates, and "fingerprints" of their contributions must occur because additions of glacial ice or meltwater to the oceans will not cause a globally uniform rate of sea-level rise. As ice melts or is discharged, Earth will respond elastically, and the geoid will also adjust. The result is that large changes in relative sea level will occur near the area of melting or discharge, and significant (∼20%) deviations from a uniform global rise will occur antipodal to the source. Thus, several authors have used trends of relative sea-level rise obtained from tide gauge data to investigate possible contributions from Greenland, Antarctica, and other sources of global sea-level rise. In this paper, we consider the fingerprint question morphologically by examining the regional variations of relative sea-level change for evidence of these fingerprints. Unambiguous evidence for fingerprints of glacial melting was not found, most likely due to the presence of other signals present in sea-level records that cannot easily be distinguished. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Coastal Research is the property of KnowledgeWorks Global, Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Coastal Research is the property of KnowledgeWorks Global, Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Suffolk coast around Dunwich and Sizewell has experienced major changes during the past 2000 years, with significant loss of land caused by marine erosion. Against a background of projected acceleration in sea level rise and storminess resulting from global climate change, concern has been expressed that present coastal defences may become unsustainable in the medium to longer term, and that the survival of internationally important wildlife habitats is under threat. This paper examines the past coastal evolution in the light of natural processes, and provides a discussion of future management options. Based on analysis of historical maps, charts, air photographs, and ground survey data, it is shown that rates of coastal erosion have actually been much lower in the last 50 years than historically, and at present there is little scientific evidence to support a case for large-scale managed realignment or abandonment of flood and coastal defences. However, in some areas, notably the very northern end of the Minsmere barrier and the middle part of the Dunwich-Walberswick barrier, local realignment and/or construction of stronger secondary flood defences are required to establish a coastal condition that is more in equilibrium with current processes, and to provide adequate protection against marine flooding even under present climatic and sea level conditions. [ABSTRACT FROM AUTHOR]

The article by PASKOFF (2004)—PASKOFF, R., 2004. Potential implications of sea-level rise for France. Journal of Coastal Research, 20(2), 424-434—is discussed is this paper. We present evidence that a geomorphological analysis of the coastal and deltaic processes gives different results than those exposed by PASKOFF (2004). [ABSTRACT FROM AUTHOR]

ABSTRACT Tuck, M.E.; Ford, M.R.; Masselink, G., and Kench, P.S., 2018. Physical Modelling of Reef Platform Hydrodynamics. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 491–495. Coconut Creek (Florida), ISSN 0749-0208. Low-lying coral reef islands are considered extremely vulnerable to the implications of climate change, particularly sea level rise. Over the last decade numerical modelling has been the primary method used to predict the future state of coral reef islands in response to rising sea level. However, disregarding complex island morphodynamics, numerical models treat islands as geomorphically inert landforms despite evidence showing islands fluctuate in size, shape and position on the reef flat across a range of timescales. In order to improve our understanding and incorporate reef island morphodynamics into predictive models, a physical modelling methodology is applied to a motu, a gravel island generally located on the windward side of coral reef atolls. Physical modelling experiments took place in the Coastal Basin at the COAST laboratory, Plymouth University, UK. A 1:50 scale reef platform was constructed based on the morphology of the reef platform on the windward side of Funafuti atoll, Tuvalu. Wave processes on the reef platform have a strong influence on island geomorphology and therefore accurate replication of the hydrodynamic processes are a crucial aspect of successfully physically modelling island morphodynamics. This paper details the reef platform hydrodynamics observed during 18 experiments where wave height, wave period and water level were varied. Results highlight the successful application of physical modelling to reproduce field observations of reef platform hydrodynamics in the flume, demonstrating the accuracy of the scaled physical modelling experiments. [ABSTRACT FROM AUTHOR]

Lim, H.S.; Lee, H.J.; Kim, D., and Hong, S., 2023. Beach erosion along the eastern coast of Korea: A brief review. Journal of Coastal Research, 39(1), 181–190. Charlotte (North Carolina), ISSN 0749-0208. Most of the beaches on the eastern coast of Korea are eroding at an alarming rate, triggered by combined natural and artificial causes. In this review, each of the major causes of beach erosion is addressed briefly. A few protection measures such as breakwaters and nourishments are also discussed, with the emphasis on the unexpected or undesirable outcomes. Finally, some of the essential requirements for the field measurements in a beach are mentioned. Global warming has induced the chief natural causes of the beach erosion in Korea, including a gradual increase in wave energies and sea level. An estimation in this review suggests the rates of shoreline of 1 m/10 yrs on the eastern coast by sea-level rise alone. By comparison, artificial beach erosion is most likely to occur upon emplacing structures nearby. A variety of the artificially erosional cases by beach developments are described in the review. Storms and typhoons play a critical role in eroding beaches and changing local morphologies in a short period of time and thus should be observed hydrodynamically. However, the diminishing run-off of rivers and streams should be regarded as the primary reason for the nationwide artificial erosion of beaches. The scanty supply of stream sands to the beaches, together with the influence of global warming, would have the beaches eroded continuously without any coastal developments. [ABSTRACT FROM AUTHOR]

Lester, C.; Griggs, G.; Patsch, K., and Anderson, R., 2022. Shoreline retreat in California: Taking a step back. Journal of Coastal Research, 38(6), 1207–1230. Coconut Creek (Florida), ISSN 0749-0208. Adapting to long-term sea-level rise has emerged as perhaps the most significant coastal management challenge of the 21st century. But this challenge has become fraught with controversy in California, especially around the idea of managed retreat. This article reframes the current adversarial and highly politicized dichotomous controversy about managed retreat with an overview of California's actual experience managing coastal shoreline hazards over the last half-century. The review shows that managed retreat in California is more than an either-or fight about private beachfront residential property. The article reviews a range of cases in which development or development potential has been moved back from the shoreline. The cases stand in contrast to the overly simplified debate about managed retreat and show that retreat has been happening on California's coast for decades. The discussion identifies the complexity and multiple dimensions of shoreline adaptation over long periods and concludes with some observations in hopes of shedding light on and opening more reasonable discussion of pathways to shoreline retreat and resilient communities. [ABSTRACT FROM AUTHOR]

Youn, S. and Zarillo, G., 2022. Morphological analysis of barrier islands in the Nakdong River Estuary, South Korea. Journal of Coastal Research, 38(3), 475–490. Coconut Creek (Florida), ISSN 0749-0208. The Nakdong Estuary system and the associated barrier island system near Busan, South Korea, consists of dynamic shorelines characterized by morphological transformations that result from natural disasters (typhoons and flooding), rising sea levels, and construction projects (the Nakdong Estuary Dam and the Busan Newport). This study aims to synthesize existing water level, wave, meteorological, and morphological data obtained from various institutions with the objective of identifying major factors that influence shoreline and area change over time. These objectives were met by analyzing the shoreline and area with direction analysis from center point (DACP) to consider the influence of river discharge and sea-level rise and to determine shoreline shifts in barrier island orientation over time. From DACP, it was determined that the Nakdong barrier islands rotated clockwise because of erosion and deposition. Offshore shorelines of barrier islands advanced by 0.1 to 2 km between 1972 and 2013. The area change rate between 1972 and 2013 was 20.85% from 100 to 180° because of the Maenggeummeori-do channel construction and discharge from the Nakdong Estuary Dam. Morphological changes and shifts in shoreline positions were caused by alteration of flow patterns because of construction of the Nakdong Estuary Dam and sea-level rise in the Nakdong Estuary system based on the timeline of the shoreline and area change rates. This study exemplifies the need for a preconstruction development plan in a study area to ensure that the results of a project are environmentally sound with respect to the potential impacts of project construction and sea-level rise. [ABSTRACT FROM AUTHOR]

Over the past 40 years, consideration of tile potential effect of sea level rise on sandy coasts has been dominated by the conceptual model proposed in the Bruun Rule, which is used to predict the horizontal translation of the shoreline associated with a given rise in sea level. A review of the hypotheses that form the basis for this two-dimensional model suggests that the assumption of net sand transfer to the nearshore profile and deposition of a thickness of sediment equal to the rise in sea level is probably incorrect. Moreover, the model omits consideration of a significant component of the coastal sediment budget, namely the dune sediment budget, and the processes associated with beach-dune interaction. An alternative conceptual model is developed on the basis of a two-dimensional equilibrium profile similar to that which forms the basis for the Bruun Model. The proposed model incorporates consideration of the dune sediment budget and foredune dynamics. In contrast to the Bruun Model, it predicts no net transfer of sediment to the nearshore profile and preservation of the foredune through landward migration. It is argued that the model proposed here offers a better starting point for developing more realistic models of shoreline response to sea level rise that incorporate consideration of alongshore sediment transfers and more complex coastal morphology and sediment characteristics. Testing of the validity of the model and its potential use for integrated coastal zone management will require consideration of the volume changes associated with sea level rise on a decadal scale. [ABSTRACT FROM AUTHOR]

Stotts, S.; Callahan, J., and Gulledge, O., 2021. Impact of channel dredging and straightening in an Atlantic white cedar (Chamaecyparis thyoides L. (B.S.P.)) freshwater tidal wetland. Journal of Coastal Research, 37(5), 973–986. Coconut Creek (Florida), ISSN 0749-0208. Once prominent up the eastern coast of the United States, freshwater wetlands with Atlantic white cedar (AWC; Chamaecyparis thyoides L. (B.S.P.)) are now vanishing due to saltwater intrusion and anthropogenic landscape alterations. This study utilizes a historic, anthropogenic disturbance to provide insight into the AWC response to salinization. A major straightening and dredging project in the 1920s, including 16 oxbow cuts, allowed brackish water to move upstream in the St. Jones River in Dover, Delaware, leading to the die-off of an AWC swamp. The sampled AWC experienced climate change, storms, hydrologic alterations, and sea-level rise. Annual ring width and suppression event chronologies were developed from dead AWC and were compared to groupings of climate variables in the predisturbance (1895–1920) and postdisturbance (1928–1958) periods. Results of the dendrochronological analysis indicate that the AWC in this study died at an average age of 49.3 years, earlier than typically expected for such species. After the straightening and dredging, the AWC experienced changes in growth response to temperature while suppression events became positively correlated with elevated temperature (p = 0.024) and high precipitation (p = 0.019). The system also showed signs of becoming more sensitive to storm events in the postdisturbance period. [ABSTRACT FROM AUTHOR]

The quantity and quality of long sea level records from the Mediterranean reflects to a great extent the situation pertaining globally. There are a few, high quality records, but not as many as one would like, and those that do exist are not distributed uniformly along the whole coastline. The longest records provide precise estimates of 'relative' sea level trends, but uncertainties in determining rates of vertical land movement preclude accurate measurement of 'regional eustatic' change for comparison to assessments from climate change studies. The northern Mediterranean records can be used to demonstrate the ability to extract information on differential vertical land movements from such data, as can sea level records from many other parts of the world, and to underline the importance of long term recording to locations at risk from potential future sea level changes. This paper will review these 'global' issues from the regional perspective. [ABSTRACT FROM AUTHOR]

Brunel, C. and Sabatier, F., 2007. Pocket beach vulnerability to sea-level rise. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 604 – 609. Gold Coast, Australia, ISSN 0749.0208 The objective of this paper is to quantify the role of relative sea-level rise in the retreat of the shoreline and to evaluate this retreat in terms of future sea-level rise on 23 pocket beaches in Provence (France). Between 1896 and 1998, all of the investigated pocket beaches underwent erosion, with an average retreat of 12.1 (± 3.5) m. Making use of the flooding principle, and assuming a relative sea-level rise of +11 cm between 1896 and 1998, we obtain an average shoreline retreat of 5.8 (± 3.5) m. A comparison between measured average retreat and calculated average retreat suggests that sea-level rise is one of the main factors influencing shoreline retreat (50% of shoreline retreat can be explained by sea-level rise). The position of the shoreline for 2100 is evaluated not only by using the historical shoreline trend and the flooding method but also by adding the historical shoreline trend and the flooding concept in the case of an increase in sea-level of about +44 cm (for 2100). On the investigated pocket beaches, the presence of a cliff 'blocking' the landward migration of the profile will lead to a significant reduction in beach width. Thus, we envisage that the pocket beaches will lose 75 % to 97 % of their present surface area. In other words, we predict the eventual disappearance of the pocket beaches in Provence. [ABSTRACT FROM AUTHOR]

Watson, P.J., 2019. Updated mean sea-level analysis: South Korea. Journal of Coastal Research, 35(2), 241–250. Coconut Creek (Florida), ISSN 0749-0208. The threat of sea-level rise to the heavily populated Korean Peninsula has profound and far-reaching implications. This study updates and extends the several previous works undertaken to analyse tide-gauge records and satellite altimetry around South Korea using enhanced time-series analysis techniques to detect coastal vertical land motion and current rates of rise and accelerations in mean sea level to augment planning, design, and risk management activities. Although the longest tide-gauge records available only date back to 1960, every effort has been made to separate the mean sea-level trend from the more dynamic influences with improved precision using state-of-the-art analytical techniques. The analysis identified general trends of subsidence observed around the margins bounded by the East China Sea and East Sea (Sea of Japan) below 36°N, whereas uplift was a more prevalent feature along the margins bounded by the Yellow Sea. All tide-gauge records longer than 50 years exhibited 'relative' mean sea-level rise increasing marginally over the length of the record, suggesting the presence of an acceleration; however, the estimated time-varying accelerations (albeit predominantly positive) are small and not statistically different from zero (95% confidence interval). Although the average trend of sea-surface height from satellite altimetry across this region was 3.2 mm/y, key spatial variations were evident, with the highest rates of rise centred in two discrete areas east and west of South Korea around 37.5°N, each exceeding 8 mm/y. [ABSTRACT FROM AUTHOR]

Smith, S.M.; Tyrrell, M.; Medeiros, K.; Bayley, H.; Fox, S.; Adams, M.; Mejia, C.; Dijkstra, A.; Janson, S., and Tanis, M., 2017. Hypsometry of Cape Cod salt marshes (Massachusetts, U.S.A.) and predictions of marsh vegetation responses to sea-level rise. The structure and functioning of salt marsh ecosystems are being impacted by sea-level rise, and a major determinant of their vulnerability to this aspect of climate change is their ground surface elevation relative to tide heights (hypsometry). In this study, a comprehensive real-time kinematic (RTK) global positioning system (GPS) survey was conducted within four salt marshes at Cape Cod National Seashore (CCNS) to create digital elevation models, and in situ water-level loggers were used to collect tidal data within each system. From these data, marsh surface elevations were calculated relative to mean high tide elevations for 2013 and projected elevation change rates with 50 cm and 100 cm of sea-level rise. Vegetation responses to these scenarios were then modeled based on the relationship of high and low marsh zones to relative elevation. The results suggest that (1) CCNS marshes sit low within their tidal frames, unlike the majority of salt marshes in New England, (2) high marsh areas will be most affected with sea-level rise, with 90-100% losses under both 50 cm and 100 cm sea-level rise scenarios, and (3) total marsh losses of up to 30% could ensue with 100 cm of sea-level rise. Such changes, should they occur, would substantially impact the coastal environment on Cape Cod and profoundly impact the ecosystem services provided by these systems. [ABSTRACT FROM AUTHOR]

Antón, A.I.; de la Peña, J.M.; Almazán, J.L., and Lechuga, A., 2016. Appropriate locations for geotextile bag revetments: An analysis. Social pressure exerted by urban development, the increase in erosion on many coastal stretches, and the rise in sea level due to climate change over the last few decades have led governments to increase investment in coastal protection. In turn, a reduction in costs and increases in ease of construction and rate of implementation have led to sand-filled geotextile elements, such as bags, tubes, and containers, becoming an alternative or supplement to traditional coastal defence materials, such as rubble mounds, concrete, and so on. Not all coastal zones are appropriate for sand-filled geotextile structures as coastal defences. This article analyses suitable zones for locating geotextile bag revetments to protect coasts from storm erosion and concludes that the least suitable zones are the surf zone (on an open coast and on a slightly protected coast) and deep water (on an open coast), except if a suitable reinforcement is carried out when the demand makes it necessary this build this kind of defence. [ABSTRACT FROM AUTHOR]

Albrecht, F. and Shaffer, G., 2016. Regional sea-level change along the Chilean coast in the 21st century. Regional sea-level change for Chile is considered until the end of the 21st century for the representative concentration pathway (RCP)4.5 and RCP8.5 scenarios. The main components that contribute to sea-level change are analyzed and summed to achieve a total estimate of sea-level change along the coast of Chile and in the Southeast Pacific. Included are the steric/dynamic component, the contribution from land ice loss, and the sea-level change due to the glacial isostatic adjustment. Regional fingerprints and global means are combined to estimate sea-level change in this area. For the steric/dynamic component two different estimates are considered. The results are compared with those found in the Intergovernmental Panel on Climate Change Fifth Assessment Report. The total mean sea-level rise along the coast lies between 34 cm and 52 cm for the RCP4.5 scenario and between 46 cm and 74 cm for the RCP8.5 scenario, depending on the location and the steric/dynamic component estimate considered. This component is the main contribution in each scenario. All estimates show a modest, relatively constant decrease in sea-level rise along the coast from north to south. [ABSTRACT FROM AUTHOR]

Oh, S.M.; Moon, I.-J., and Kwon, S.J., 2016. Increasing the highest storm surge in Busan harbor, In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 760-764. Coconut Creek (Florida), ISSN 0749-0208. One of the most pronounced effects of climate change in coastal regions is sea level rise and storm surges. Busan in particular, the fifth largest container handling port in the world, has suffered from serious storm surges and experienced a remarkable mean sea level (MSL) rise. This study investigates a long-term variation of annual maximum surge height (AMSH) using sea level data observed in Busan over 53 years (1962∼2014). The decomposition of astronomical tides and surge components shows that the AMSH has increased 18 cm over 53 years ( i.e., 3.5 mm/year), which is much larger than the MSL trend (2.5 mm/year) in Busan. This significant increase in AMSH is mostly explained by the increased intensity of landfall typhoons over the Korean peninsula (KP), which is associated with the increase of sea surface temperature and the decrease of vertical wind shear at mid-latitudes of the western North Pacific. In a projected future warming environment, the combination of an increasing MSL and AMSH will accelerate the occurrence of record-breaking extreme sea levels, which will be a potential threat in Busan harbor. [ABSTRACT FROM AUTHOR]

Suh, S.W., 2016. Tidal asymmetry and energy variations due to sea-level rise in a macro tidal bay. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 765-769. Coconut Creek (Florida), ISSN 0749-0208. Multiple coastal constructions at shallow depths in macro tidal environments, have resulted in remarkable coastal hydrodynamic alteration resulting in tidal asymmetry, energy flux, and dissipation. Consequently, the temporal aspect of sedimentation has changed abruptly and can eventually cause long-term variations. These anthropogenic alterations should be precisely investigated in relation to sea-level rise (SLR) in order to mitigate unexpected consequences. To understand alteration of tidal asymmetry due to SLR, gamma parameters that combine the traditional tidal amplitude ratio of M4/M2 and phase-lag difference were evaluated using the ADvanced CIRCulation (ADCIRC) model under finely resolved complex coastal geometry. Moreover, tidal energy flux and dissipation changes, in relation to tidal-flat area, were examined in Gyeonggi Bay, South Korea. As a result of SLR, spatial change in tidal asymmetry would occur; moreover, gamma parameter intensity, which shows flood dominance, would attenuate. M2 and M4 tidal energy flux would be lessened by SLR. For the energy dissipation, slight change appeared in M2, while lessening tidal flat area directly affected reduction in M4 based on SLR scenarios. Because a small change in tidal asymmetry could yield long-term morphological changes in the macro tidal environment, these alterations should be treated as important. A numerical restoration test removal of Siwha Dike, which behaved as a tipping point on tidal asymmetry, revealed that even a SLR scenario did not have significant effect if the natural shoreline persists. Thus, future studies should be focused on the importance of long-term impact on tidal alteration induced by coastal construction. [ABSTRACT FROM AUTHOR]

Schubert, J.E.; Gallien, T.W.; Majd, M.S., and Sanders, B.F., 2015. Terrestrial laser scanning of anthropogenic beach berm erosion and overtopping. Anthropogenic berms are widely deployed to manage coastal flooding. The dynamic erosion of scraped berms exposed to waves and a rising tide in southern California was monitored with a terrestrial laser scanner (TLS) on three occasions in February and March of 2012. An improved characterization of initial berm geometry and the dynamics of berm erosion was pursued to accurately predict the onset and impact of coastal flooding associated with berm erosion and overtopping. TLS is shown to yield a digital terrain model (DTM) with a vertical accuracy of ca. 3 cm, indicating it is an excellent source of data for initializing mechanistic and/or empirical models that could be used to predict the onset and rate of wave overtopping. Minimum scan point spacings required to achieve this level of accuracy are investigated and reported. Additionally, a dimensionless water level representing the fractional submergence of the berm is identified as a good predictor of cumulative berm erosion under the test conditions. [ABSTRACT FROM AUTHOR]

Schmid, K.; Hadley, B., and Waters, K., 2014. Mapping and portraying inundation uncertainty of bathtub-type models. Data errors are an unavoidable reality in maps of present conditions, but with the prevalence of ease-of-use formats and software these errors are becoming less evident. In earlier maps, the resolution or scale of the information and its presentation on a physical medium ( e.g., contours) could inherently convey a level of vagueness that corresponded to the accuracy limitations. Maps of modeled output have additional accuracy considerations, especially if extrapolating future or potential events ( e.g., 100-year storm). Sea-level rise (SLR) mapping falls into this category but is also highly dependent on present topographic conditions. SLR and other ecological models use continuous surfaces or digital surface models to generate derived information; however, presentation of the uncertainty information can be difficult or confusing. A technique that conveys uncertainty boundaries for a given confidence level was developed for the National Oceanic and Atmospheric Administration Coastal Services Center's SLR and inundation-visualization tool. The technique and definition of uncertainty levels described herein varies from other common methods, but the use of root-mean-square error (RMSE) to derive the assessment is similar. The technique uses the reported RMSE of both elevation and tidal surface and their relationship to a normal distribution. In this way, user-defined confidence levels can be used to map uncertainty both above and below the deterministic value produced in typical single-surface or bathtub models. The technique is used in this context for SLR and inundation mapping but also has applicability in mapping other phenomena. [ABSTRACT FROM AUTHOR]

Pilkey, O.H. and Cooper, J.A.G. 2014. Are natural beaches facing extinction? In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa) Journal of Coastal Research, Special Issue, No. 70 pp. 431-436. ISSN 0749-0208. On a generational scale, on developed shorelines, the world's recreational beaches are doomed. This is largely because of the widespread assumption that preservation of buildings is a higher priority than preservation of beaches in response to sea level rise. Continuing beach degradation will be inevitable through active or passive processes. Active degradation means the actual removal of the beach, mostly as a result of shoreline engineering or mining. By far, the most important cause of beach loss in this category will be hard structures, especially seawalls. The incorrectly but widely perceived panacea of each replenishment will become economically impossible because of raised sea levels. Replenishment leads to intensified beachfront development and this ironically and inevitably will increase the future construction of seawalls. Passive degradation refers to reduction of the quality of the beach to the point that human usage drops, along with political support for costly beach preservation by nourishment. Passive degradation includes trash accumulation, oil spills, beach driving and most importantly, pollution, which is increasing rapidly apace with population growth and remains largely unrecognized by the beach-using public. [ABSTRACT FROM AUTHOR]

Yoshida, J., Udo, K., Takeda, Y., Mano, A., 2014. Framework for proper beach nourishment as adaptation to beach erosion due to sea level rise. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 467-472, ISSN 0749-0208. Beach erosion caused by sea level rise is a serious problem for people over the world. Beaches play important roles in disaster prevention, recreational use, and nurturing unique ecosystems. Beach nourishment is capable of maintaining the position of the shoreline and the natural environment. However, applying artificial nourishment to the whole beach area is not a practical method due to high costs and the large quantity sand required. There has been no framework for effective adaptation of beach nourishment to solving coastal erosion issues. In this study, we focus on the beach nourishment as an adaptation to beach erosion due to sea level rise and attempt to construct a framework for proper beach nourishment. The framework for the adaptation proposal is as follows: (i) Prediction of shoreline changes and future beach width due to sea level rise; (ii) Determination of beach width to be protected in terms of disaster prevention, ecosystem conservation and recreation respectively; (iii) Specifying vulnerable areas where the area of and width of the beach Step; (iv) Estimation of sand volume and its cost applied only to the vulnerable area. This framework was applied to Japanese beaches where the determine beach width indicated that when a beach width of more than 10 m is needed for prevention against disasters, more than 20 m for ecosystem conservation, and more than 30 m for recreation use. The volume of sand required to maintain the beach width along the whole Japanese beach varies from 61× 106 to 2,300× 106 m3, and by the use of this framework, it is possible to estimate practical nourishment volume and its associated costs for disaster prevention, ecosystem conservation and recreation use. [ABSTRACT FROM AUTHOR]

An underwater survey of the Maldives archipelago has documented various types of erosion features in the Pleistocene reef rock record. Among these were several littoral notches, whose equivalent is found in many other parts of the world. The morphology of the notches at -24 and -35 m suggests that the decelerations of the Holocene transgression were true standstills, or episodes of very slow rise, followed by episodes of rapid rise of the water level. Some deeper water notches were also surveyed. Many caves and cavities in the Pleistocene reef rock, although excavated during low glacial levels, appear to have also been reworked by marine erosion during the Holocene rise. Deep dissection of old cavities by bioerosive action leads to frail, hooplike formations, unable to stand their own weight on dry land. Despite the difficulty of dating such formations as notches, their correspondence with similar features observed in other regions is striking. [ABSTRACT FROM AUTHOR]

Garcin, M., Baills. A., Le Cozannet, G., Bulteau, T., Auboin, A-L., Sauter, J., 2013. Pluri-decadal impact of mining activities on coastline mobility of estuaries of New Caledonia (South Pacific) This work aims at analysing the relative impact of sedimentary supply by rivers versus the effect of sea level rise and other processes over the last 5 decades of some representative coastal stretches of New Caledonia (South Pacific Ocean). The study of twelve coastal estuarine stretches has shown erosion rates ranging from −1.8m/y to accretion rates up to 5.5m/y over the last 50 years. During this time, the climate component of sea level rise has been evaluated around 0.5mm/y in Nouméa and can be considered identical on the studied island. Vertical movements affecting New Caledonia are suspected to be different between western and eastern parts of the island. Nevertheless, in areas with homogeneous vertical movement, the coastal stretches studied show various evolution rates. The analysis of accreting estuarine coastal areas shows that this evolution is linked to sedimentary supply from rivers. On New Caledonia Island, the creation of bare soils by nickel mining during the last 50 years has increased erosion processes on the watersheds and the solid discharge of the rivers. The study shows a strong correlation between the percentage of bare soil surfaces (up to 3.7 % of the watershed surface) generated by nickel mining and the coastline evolution rate (from −2m/y to +4m/y) around the estuaries of each watershed. Therefore, mining activity on watersheds is suspected to have been the major forcing factor of recent coastal changes during the last fifty years. [ABSTRACT FROM AUTHOR]

The potential risk and effects of storm-surge damage caused by the combination of hurricane-force waves, tides, and relative sea-level-rise (RSLR) scenarios were examined at the U.S. Naval Station, Norfolk, Virginia. A hydrodynamic and sediment transport modeling system validated with measured water levels from Hurricane Isabel was used to simulate two synthesized storms representing 50-year and 100-year return-period hurricanes, a northeaster, and five future RSLR scenarios to evaluate the combined impacts of inundation on this military installation in the lower Chesapeake Bay. The naval base topography and nearshore water body of Hampton Roads were included in the coastal modeling system (CMS), a suite of surge, circulation, wave, sediment transport, and morphology evolution models. The modeling domain was a rectangular area covering the entire Naval Station Norfolk in the Hampton Roads and the mouths of the James and Elizabeth rivers. A variable-resolution grid system was created with a finer resolution of 10 m in the naval base and a coarser resolution of 300 m in the regions away from the base. The boundary-forcing conditions to the CMS were regional storm surge produced by the ADvanced CIRCulation (ADCIRC),and wave conditions by the Simulating WAve Nearshore (SWAN) model. The CMS calculated the local water-surface elevation and storm-surge inundation for combined RSLR, surge, waves, and wind. Results indicate that synthetic storms would cause extensive inundation of coastal land around the naval base. Approximately 60% of the land would be under water with the 100-year storm for the present sea level, and 80% for estimated RSLR of 2 m. [ABSTRACT FROM AUTHOR]

The results from analyses of cores and pits carried out during two research campaigns in the littoral lagoon of Albufereta d'Alacant (Western Mediterranean) shed light on the sedimentary dynamics of this area. The erosive sequence and stages recorded in periods prior to the Middle Holocene bear witness to the environmental changes that occurred in the littoral zone between isotope stages 2 and 1 in relation to the rise in sea level during the Holocene. As the rise in the sea level slowed, a freshwater lagoon environment formed around 4000 YBP. After that time, the changes in the littoral environment became less pronounced and were caused by atmospheric circulation in the Northern Hemisphere. Around 3000 YBP, a lagoon open to the sea emerged as the result of a relative change in the sea level. This environment lasted approximately until 1500 YBP. The prolonged survival of the lagoon created by this event and the increase in the marine influence during the later stages of the lagoon's development may be connected with human management of the environment in the Roman era. It was followed by a restricted lagoon environment characterized by cyclical changes in the environment lasting hundreds of years. [ABSTRACT FROM AUTHOR]

Sea-level rise rates have become important drivers for policy makers dealing with the long-term protection of coastal populations. Scenario studies suggest that an acceleration in sea-level rise is imminent. The anticipated acceleration is hard to detect because of spatial and temporal variability, which consequently, have become important research topics. A known decadal-scale variation is the 18.6-year nodal cycle. Here, we show how failing to account for the nodal cycle resulted in an overestimation of Dutch sea-level rise. The nodal cycle is present across the globe with a varying phase and a median amplitude of 2.2 cm. Accounting for the nodal cycle increases the probability of detecting acceleration in the rate of sea-level rise. In an analysis of the Dutch coast, however, still no significant acceleration was found. The nodal cycle causes sea level to drop or to rise at an increased rate; therefore, accounting for it is crucial to accurately estimate regional sea-level rise. [ABSTRACT FROM AUTHOR]

Mombasa is the second largest city in Kenya and the largest international seaport in East Africa, with over 650,000 inhabitants. The city has a history of natural disasters associated with extreme climatic events, most recently, the severe rain-induced flooding in October 2006, which affected about 60,000 people and caused damage to important infrastructure. Because the city is expected to continue to experience rapid growth, the future impacts of such events can only increase. Changes in sea level and storm surges are components of climate change that have the potential to further increase the threats of flooding within the city. This geographic information system-based study provides a first quantitative estimate, both now and through the twenty-first century, of the number of people and associated economic assets potentially exposed to coastal flooding due to sea-level rise and storm surges in Mombasa. The current exposure to a 1 : 100 y extreme water level for the Mombasa district is estimated at 190,000 people and US$470 million in assets. About 60% of this exposure is concentrated in the Mombasa Island division of the city, where about 117,000 people (2005 estimate) live below 10 m elevation. By 2080, exposure could grow to over 380,000 people and US$15 billion in assets, assuming the well-known A1B sea-level and socioeconomic scenario. Future exposure is more sensitive to socioeconomic than climate scenarios. However, there is significant scope within the city limits to steer future development to areas that are not threatened by sea-level rise. Hence, forward planning to focus population and asset growth in less vulnerable areas could be an important part of a strategic response to sea-level rise. The methods used here could be applied more widely to other coastal cities in Africa and elsewhere to better understand present and future exposure and worst-case risks due to climate change and rising sea levels. [ABSTRACT FROM AUTHOR]

KETTLE, N.P., 2012. Exposing compounding uncertainties in sea level rise assessments. Coastal communities and ecosystems, including those along the Carolina coast of the eastern United States, are at risk to permanent or episodic inundation, contamination of freshwater supplies, and a host of other climate change related environmental hazards due to sea level rise. In order to guide development of mitigation and adaptation strategies, stakeholders will require information on baseline conditions and projections of change. However, the interpretation of impact assessments is not always straightforward given the uncertainties in measuring relative sea level rise, the challenges in predicting the magnitude of change, and the difficulty in acquiring appropriate data and methodologies for quantifying impacts. In addition, many sea level rise assessments are not at spatial or temporal scales most relevant for decision makers. In the context of sea level rise assessments, this study presents a model to describe the various sources of compounding uncertainty that can compromise evaluations and complicate interpretations. Sea level trends and impacts along the Carolina coastline-a region at risk to significant economic and environmental losses-are then reviewed as a means of (1) illustrating the compounding sources of uncertainty and (2) testing the state of our knowledge and identifying information gaps and processing limitations that impede understanding adaptation to sea level rise. [ABSTRACT FROM AUTHOR]

Accelerating sea-level rise associated with global climate change will affect sedimentary processes on coral reefs and other shoreline environments by increasing energy and sediment resuspension. On reefs, sedimentation is known to increase coral stress and bleaching as particles that settle on coral surfaces interfere with photosynthesis and feeding, and turbidity induced by suspended sediment reduces incident light levels. Using relationships developed from observations of wave orbital velocity, water-surface elevation, and suspended-sediment concentration on a fringing reef flat of Molokai, Hawaii, predictions of the average daily maximum in suspended-sediment concentration increase from ∼11 mg/l to ∼20 mg/l with 20 cm sea-level rise. The duration of time concentrations exceeds 10 mg/l increases from 9% to 37%. An evaluation of the reduction of wave energy flux through breaking and frictional dissipation across the reef flat shows an increase of ∼80% relative to the present will potentially reach the shoreline as sea level increases by 20 cm. Where the shoreline exists on low, flat terrain, the increased energy could cause significant erosion of the shoreline. Considering the sediment budget, the sediment flux is predicted to increase and removal of fine-grained sediment may be expedited on some fringing reefs, and sediment in storage on the inner reef could ultimately be reduced. However, increased shoreline erosion may add sediment and offset removal from the reef flat. The shifts in sediment availability and transport that will occur as result of a modest increase in sea level have wide application to fringing coral reefs elsewhere, as well as other shoreline environments. [ABSTRACT FROM AUTHOR]

Integration of impacts of sea-level rise to coastal zone management practices are performed through coastal vulnerability assessments. Out of the types of vulnerability assessments, a proposed model demonstrated that relative vulnerability of different coastal environments to sealevel rise may be quantified using basic information that includes coastal geomorphology, rate of sea-level rise, and past shoreline evolution for the National Assessment of Coastal Vulnerability to Sea-Level Rise for U.S. Coasts. The proposed methodology focuses on identifying those regions where the various effects of sea-level rise may be the greatest. However, the vulnerability cannot be directly equated with particular physical effects. Thus, using this concept as a starting point, a coastal vulnerability matrix and a coastal vulnerability index that use indicators of impacts of sea-level rise are developed. The developed model compares and ranks different regions according to their vulnerabilities while prioritizing particular impacts of sea-level rise of the region. In addition, the developed model determines most vulnerable parameters for adaptation measures within the integrated coastal zone management concept. Using available regional data, each parameter is assigned a vulnerability rank of very low to very high (1-5) within the developed coastal vulnerability matrix to calculate impact subindices and the overall vulnerability index. The developed methodology and Thieler and Hammar-Klose the proposed methodology were applied to the Göksu Delta, Turkey. It is seen that the Göksu Delta shows moderate to high vulnerability to sea levelsea-level rise. The outputs of the two models indicate that although both models assign similar levels of vulnerability for the overall region, which is in agreement with common the literature, the results differ significantly when in various parts of the region is concerned. Overall, the proposed Thieler and Hammar-Klose method assigns higher vulnerability ranges than does the developed coastal vulnerability index sea-level rise (CVISLR) model. A histogram of physical parameters and human influence parameters enables enable decision makers to determine the controllable values using the developed model. [ABSTRACT FROM AUTHOR]

The importance of sea-level rise in shaping coastal landscapes is well recognized within the earth science community, but as with many natural hazards, communicating the risks associated with sea-level rise remains a challenge. Topography is a key parameter that influences many of the processes involved in coastal change, and thus, up-to-date, high-resolution, high-accuracy elevation data are required to model the coastal environment. Maps of areas subject to potential inundation have great utility to planners and managers concerned with the effects of sea-level rise. However, most of the maps produced to date are simplistic representations derived from older, coarse elevation data. In the last several years, vast amounts of high quality elevation data derived from lidar have become available. Because of their high vertical accuracy and spatial resolution, these lidar data are an excellent source of up-to-date information from which to improve identification and delineation of vulnerable lands. Four elevation datasets of varying resolution and accuracy were processed to demonstrate that the improved quality of lidar data leads to more precise delineation of coastal lands vulnerable to inundation. A key component of the comparison was to calculate and account for the vertical uncertainty of the elevation datasets. This comparison shows that lidar allows for a much more detailed delineation of the potential inundation zone when compared to other types of elevation models. It also shows how the certainty of the delineation of lands vulnerable to a given sea-level rise scenario is much improved when derived from higher resolution lidar data. [ABSTRACT FROM AUTHOR]

Barrier-island chains worldwide are undergoing substantial changes, and their futures remain uncertain. An historical analysis of a barrier-island chain in the north-central Gulf of Mexico shows that the Mississippi barriers are undergoing rapid systematic land loss and translocation associated with: (1) unequal lateral transfer of sand related to greater updrift erosion compared to downdrift deposition; (2) barrier narrowing resulting from simultaneous erosion of shores along the Gulf and Mississippi Sound; and (3) barrier segmentation related to storm breaching. Dauphin Island, Alabama, is also losing land for some of the same reasons as it gradually migrates landward. The principal causes of land loss are frequent intense storms, a relative rise in sea level, and a sediment-budget deficit. Considering the predicted trends for storms and sea level related to global warming, it is certain that the Mississippi-Alabama (MS-AL) barrier islands will continue to lose land area at a rapid rate unless the trend of at least one causal factor reverses. Historical land-loss trends and engineering records show that progressive increases in land-loss rate correlate with nearly simultaneous deepening of channels dredged across the outer bars of the three tidal inlets maintained for deep-draft shipping. This correlation indicates that channel-maintenance activities along the MS-AL barriers have impacted the sediment budget by disrupting the alongshore sediment transport system and progressively reducing sand supply. Direct management of this causal factor can be accomplished by strategically placing dredged sediment where adjacent barrier-island shores will receive it for island nourishment and rebuilding. [ABSTRACT FROM AUTHOR]

The world's sandy beaches, already eroding at rates of concern to coastal managers, are facing a further threat based on predictions of global climate change. Although mean sea level rise has long been recognized as a likely consequence of climate change, it has been suggested that there may also be a change in ocean storminess—that is, the intensity and frequency of storm events. While the effects of a change in wave height can be handled with existing analysis methods, the effects of a change in the rate at which storms arrive are less obvious and harder to predict. As a prelude to model studies investigating coastal response to changes in storminess, it is necessary to have a reliable method for generating storm and wave histories that contain waves that not only conform to known distributions of height and period but that also arrive at the proper rate in time. In the current work a statistical model of the arrival rate of storms and the wave heights within those storms has been developed. Storminess can be modelled by describing interstorm period, storm duration, the average wave height, and the temporal distribution of storm significant wave heights using methods that have been applied in rainfall modelling. The model has been verified against existing wave climate parameters of wave exceedence and wave persistence, and it has been shown to reproduce these statistics reliably. [ABSTRACT FROM AUTHOR]

During the Holocene, the western part of the present-day Thessaloniki coastal plain (north-central Greece) was flooded by the rising sea level and formed a bay as a consequence of the last postglacial transgression. The rate of the sea-level rise subsequently decelerated, and this bay began to fill with sediments delivered by the Aliakmon and Axios, as well as by other smaller rivers. The palaeogeographic and palaeoenvironmental reconstruction of the Thessaloniki Plain was the focus of several studies published during the past century. Most of these studies are based on the interpretation of historical sources and support the assumption of a fast filling of the bay between the fifth century BC and the fifth century AD. In this work, we first present the results of the analysis of data collected from six boreholes recently drilled in the western part of the plain, up to the western bank of the Axios River. Our study was mainly based on sedimentological and palaeontological analyses and accelerator mass spectrometry and conventional radiocarbon dating of shells and peat. Second, we evaluate the results of this study, as well as of other geological studies, which permit the description of the large-scale stratigraphic pattern of the plain. Data were evaluated on the basis of a geographic information system, used for the first time in such type of work, and were supplemented and assessed with analysis of Landsat imagery. Based on this evidence, we propose a new, detailed palaeogeographic reconstruction for the evolution of the Thessaloniki Plain during the Late Holocene. This plain corresponded to a wide marine bay during the Neolithic times (6000 BP), and later it was characterised by a fast displacement of the shoreline, mainly during Late Bronze Age, Iron Age, and Classical-Archaic periods (2650-2300 BP). A slowing down of the progradation of the alluvial plain occurred during Roman times (2100-1600 BP), and the plain obtained its present-day topography during the second part of the 20th century. [ABSTRACT FROM AUTHOR]