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Black, K.P.; Baba, M.; Mathew, J.; Kurian, N.P., and Ilic, A., 2021. Guidelines to prepare India's coast for climate change. Journal of Coastal Research, 37(6), 1117–1129. Coconut Creek (Florida), ISSN 0749-0208. India's first coastal protection guidelines for climate-change adaptation are described. The guidelines are holistic, recognizing the links between engineering, economic, physical, legal, social, environmental, and governmental intricacies. Robust protection solutions under climate change for millions of coastal residents may occur only when all these facets are improved within the complex regulatory, budgetary, and practical circumstances in India. Fifty-seven specific guidelines are presented in nine categories ranging from administrative to best-practice coastal protection. An "environmental softness ladder" that ranks coastal protection methods was developed as a scientific tool to guide policy development and project implementation. "Minimum floor level" for safe building was defined for each Indian coastal state using climate-change data produced for the study by Indian and international institutes. Beaches are more stable when the net sediment transport fluxes are close to neutral. "Grand schemes," which make large-scale changes to the coast rather than continuing with piecemeal localised works, are recommended. With diverse dynamics over a long coastline in India, the 4-year study engaged an exceptionally large number of experts, agencies, government bodies, development partners, and other stakeholders. [ABSTRACT FROM AUTHOR]

Parnell, K.E. and Smithers, S.G., 2020. Regional and local variability in coastal processes in Torres Strait, Australia, and its importance for climate change planning. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 616–620. Coconut Creek (Florida), ISSN 0749-0208. In small island states or regions, climate change planning is frequently undertaken at a country or regional level, and it is assumed that problems are common and that remedial actions can be widely applied. Community members observe treatments such as seawalls elsewhere and demand similar interventions even though they may be inappropriate. Torres Strait lies between mainland Australia and Papua New Guinea and has communities on a diverse range of islands including low muddy, coral cay, volcanic and continental island types. Approaches to solving problems caused by changing coastal processes on these varied shorelines are discussed at scales from regional to specific sites. Torres Strait has two distinct wind seasons which influence wave-driven processes and lead to seasonally reversing alongshore sediment transport, with shoreline dynamics also controlled by coastal orientation and the beach / reef flat interactions. The low muddy islands have limited management options, requiring shore protection and elevation. Shorelines on coral cay islands and the volcanic and continental islands change shape seasonally. In these settings, planning must allow for the seasonal shoreline adjustments, with structural treatments to manage longer-term shoreline trends used only to protect high-value assets and important cultural sites where alternative management responses are not possible. [ABSTRACT FROM AUTHOR]

Wegner, C.E. and Ellis, J.T., 2017. The influence of sea-level rise on wave-energy dissipation and wave-driven currents at Buck Island Reef National Monument. Modern Caribbean reefs have undergone significant degradation in the past century because of various anthropogenic stressors, which include climate-change-related impacts, hurricanes, and, potentially, sea-level rise. Degraded reefs will be unable to maintain sufficient vertical accretion with substantial increases in sea level, which will alter the hydrodynamics of these systems. A reduction in wave dissipation by reefs has the potential to shift the shorelines behind the reefs, potentially resulting in economic and habitat losses for tropical shorelines. This study focused on a barrier reef with low, live coral cover (<10%) and accretion rates comparable to current rates of sea-level rise in the region (∼1.7 mm/y). Tides served as a proxy for sea-level rise, with the spring high tide representing a future low tide. These findings indicate that at low tide, infragravity wave frequencies (0.004-0.04 Hz) dominate in the lagoon and are a function of wave breaking on the reef. At high tide, the infragravity waves are less prominent. Current velocities were higher at high tide, averaging 0.14 m s−1 vs. 0.11 m s−1 at low tide. The spectral current characteristics correlate with the infragravity wave frequencies and suggest that these waves are a driving force in lagoon circulation. Wave-energy transmission increased at high tide by 20-30% throughout the sampling period. These results suggest that with sea-level rise, infragravity band waves will be reduced and affect the stresses on the sea bed and sediment-transport processes, also allowing larger and more energetic waves to reach the shoreline. [ABSTRACT FROM AUTHOR]

Postacchini, M.; Russo, A.; Carniel, S., and Brocchini, M., 2016. Assessing the hydro-morphodynamic response of a beach protected by detached, impermeable, submerged breakwaters: A numerical approach. Coastal areas host a large fraction of the world's population and are exposed to natural extreme events, which are a serious threat to human life, as well as to economies. For this reason, sea storms are increasingly the object of studies, and the design of traditional coastal defenses is being carried out in conjunction with modeling analyses. Relying on numerical simulations performed by means of an innovative shallow-water hydro-morphodynamic model, the present work explores the overall response of a protected beach to sea storms. Numerical tests evaluate the effects of sea states extracted from realistic sea storms having different spectral characteristics, as well as the influence on beach morphology of positioning shore-parallel, impermeable, submerged breakwaters. Simulation results revealed that, while erosion/accretion patterns depend weakly on the different sea state conditions, the morphodynamics induced around the barriers is strongly influenced by the breakwaters' positioning. More specifically, at least for the forcing here analyzed, bed variations were shown to increase when the structures are progressively located offshore; on the other hand, the swash zone morphology seems to be only weakly influenced by the positioning of the breakwaters. We also observed that for an increasing extension of the volume over which dissipative breaking mechanisms occur, a decreasing inshore erosion is accompanied by an equally fast decrease of offshore erosion. Analysis of the vorticity fields shows that breakwaters placed far from the shoreline induce an evolution of the vortices generated by breaking waves rather different from the one due to breakwaters placed closer to the shoreline (which can induce seaward flows through the gap, like rip currents). [ABSTRACT FROM AUTHOR]

Al-Nasrawi, A.K.M.; Jones, B.G., and Hamylton, S. M., 2016. GIS-based modelling of vulnerability of coastal wetland ecosystems to environmental changes: Comerong Island, southeastern Australia. 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. 33-37. Coconut Creek (Florida), ISSN 0749-0208. Sustainable management of coastal zones has become a complicated issue. The majority of the human population lives along the coast, where their activities, together with a range of environmental changes, have altered the natural ecosystem processes and caused changes in coastal wetlands. To ensure sustainable use of coastal resources, a comprehensive set of modelling tools can help managers to make decisions. This study uses Comerong Island (southeastern NSW, Australia) as a case study to demonstrate the importance of modelling modifications to environmental change. Several data-based modelling approaches are employed to explore how human activities have altered this estuarine island setting over the last sixty years (1949 - 2014). Multi-temporal changes in land cover, shorelines and sediment delivery are estimated from remote sensing data, GIS analysis, and laboratory tests on water and sediment samples (grain size, X-ray diffraction and loss on ignition and water analysis). Results show there are significant changes to the areal extents and elevation of mangroves, saltmarshes and shorelines in the wetlands on Comerong Island over the time period of analysis, including northern accretion (0.4 km2), eastern, middle and southern erosion (0.7 km2) of the island. The implementation of modelling using GIS tools, water and sediment samples to monitor ecosystem processes, such as sediment transport and erosion/deposition, will allow resource managers to make more informed decisions by evaluating the potential consequences of the existing situation. [ABSTRACT FROM AUTHOR]

Osborne, P.D. and Forest, A., 2016. Sediment dynamics from coast to slope - Southern Canadian Beaufort Sea. 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. 537-541. Coconut Creek (Florida), ISSN 0749-0208. Profound changes in cross-shelf sediment fluxes are anticipated in coming decades in the southern Canadian Beaufort Sea where an accelerated increase in temperature could lead to large changes in Arctic river hydrology and coastal-marine geomorphologic processes. In the past decade sediment exported to the Beaufort Shelf has increased while sea level pressure has increased accelerating the Beaufort Gyre, strengthening coastal upwelling and expanding the Mackenzie River plume offshore. Sea-ice extent has decreased while storminess has increased increasing wave action, coastal downwelling, current surge and resuspension and transport on the shoreface and shelf. This paper investigates mechanisms, quantities and rates of sediment transport operating in this cold continental shelf-slope environment. Past studies from more than 2 decades of research are compared with recent measurements to develop improved estimates of sediment sources, pathways, fate and fluxes across the shelf and slope. In particular, we explore connections between data from a long term mooring observatory deployed over the continental shelf and slope during the ArcticNet-Industry Partnership (2009-2011) and Beaufort Regional Environmental Assessment (BREA 2011-2015) to those acquired in studies focusing on nearshore and shoreface. Sediment fluxes from the Mackenzie River and erosion of permafrost coasts are compared with outer shelf-slope measurements of settling particles and near-bottom fluxes. In turn, the role of atmospheric and cryospheric processes in forcing sediment transfer from coast to slope is investigated to assess system response to changing climate and evaluate implications for marine hydrocarbon resource development along the continental margin of the Arctic Ocean. [ABSTRACT FROM AUTHOR]

Dai, H.; Ye, M., and Niedoroda, A.W., 2015. A model for simulating barrier island geomorphologic responses to future storm and sea-level rise impacts. This paper presents the Barrier Island Profile (BIP) model, a new computer code developed to simulate barrier island morphological evolution over periods ranging between years and decades under the impacts of accelerated sea-level rise and long-term changes in the storm climate. The BIP model is a multiline model that represents the time-averaged dynamics of major barrier island features from front beach to backshore. Unique contributions of BIP to coastal modeling include a dynamic linking of interacting barrier island features and consideration of both future sea-level rise and storm climate impacts. The BIP model has the built-in capability of conducting Monte Carlo (MC) simulations to quantify predictive uncertainty caused by uncertainty in sea-level rise scenarios and storm parameters. For a series of barrier island cross-sections derived from the characteristics of Santa Rosa Island, Florida, BIP was used to evaluate their responses to random storm events and five potential accelerated rates of sea-level rise projected over a century. The MC simulations using BIP provide multiple realizations of possible barrier island morphologic responses and their statistics, such as mean and variance. The modeling results demonstrate that BIP is capable of simulating realistic patterns of barrier island profile evolution over the span of a century using relatively simple representations of time- and space-averaged processes with consideration of uncertainty of future climate impacts. [ABSTRACT FROM AUTHOR]

Solomon, J.A.; Donnelly, M.J., and Walters, L.J., 2014. Effects of sea level rise on the intertidal oyster Crassostrea Virginica by field experiments. Sea level rise predictions for the next century range from 20 to 200 cm. Coupled with climate change-related increases in storm activity and associated alterations to sediment transport, estuaries and the organisms that live in them may be impacted. Along the eastern seaboard and gulf coast of the United States, Crassostrea virginica is an economically and ecologically important estuarine shellfish species. In an effort to understand potential effects of climate change on intertidal Crassostrea virginica, a novel method for manipulating inundation time of intertidal oysters was developed to examine effects of altering daily inundation time on sedimentation, predation, and competition. Called the oyster ladder, this method consists of suspending oyster shell as recruitment substrate at different elevations within the intertidal zone between mean low and mean high water. A six-week experiment was deployed during the peak of the 2011 oyster recruitment season at two sites within Apalachicola Bay, Florida. Data was collected on oyster recruitment, shell length, presence of sessile competitors, and sedimentation. Mean oyster shell length peaked at 95% time inundated, while recruitment peaked at 80% time inundation. Maximum sedimentation occurred at the highest inundation times (95% time inundation). The oyster ladder proved to be an effective tool for manipulating inundation times for C. virginica and suggests that sea level rise will have an effect on abundance, growth and survival of this of intertidal species. [ABSTRACT FROM AUTHOR]

Leach, C.; Kennedy, D.M.; Carvalho, R.C., and Ierodiaconou, D., 2020. Predicting compartment-scale climate change impacts related to Southern Ocean wave forcing: Port Fairy, Victoria, Australia. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1157-1161. Coconut Creek (Florida), ISSN 0749-0208. On the southern coast of Australia one of the principle impacts of climate change will be a change in wave magnitude and direction resulting from intensification of the Southern Ocean storm systems. In Victoria, Australia, this is likely to cause significant change in sediment dynamics and possible shoreline re-orientation. In this paper, Port Fairy (western coast of Victoria) is used as a case study to explore the sensitivity of this embayment to changing wave climate conditions. Bed level change rates and spatially variable sediment transport rates are investigated. The results indicate that a southerly shift in the wave climate could intensify sediment transport processes and erosional patterns in this area. [ABSTRACT FROM AUTHOR]

Fernández-Fernández, S.; Silva, P.A.; Ferreira, C.C., and Carracedo-García, P.E., 2020. Longshore sediment transport estimation at Areão Beach (NW Portugal) under climate change scenario. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. (Seville, Spain). Journal of Coastal Research, Special Issue No. 95, pp. 479-483. Coconut Creek (Florida), ISSN 0749-0208. The knowledge of longshore sediment transport is essential to understand coastal systems morphological evolution, and consequent erosion/accretion processes. This research is focused on Areão Beach, a groined sandy beach, located southwards of Aveiro Lagoon (NW Portugal). The high energetic wave climate and coastline orientation induce a substantial southward net sediment transport rate. Nevertheless, this transport is interrupted by coastal defense structures resulting in erosion problems downdrift. Future changes in wave and storm climate can alter current patterns of coastal erosion. This contribution aims to characterize the longshore sediment transport rate under a future wave climate scenario. The Delft3D-WAVE module propagated wave spectral data for historical and future, corresponding to climate change scenario RCP8.5. The hydrodynamic parameters (significant wave height, peak wave period and wave direction) were extracted at offshore Areão Beach and linear wave theory was applied to obtain significant wave height and wave direction at breaking point. Then, CERC empirical sediment transport formula re-evaluated in 2013 was used to estimate longshore sediment transport values. The results disclose a change in the magnitude of longshore sediment transport and an intensification of northwards transport in the future. These findings can contribute for an adequate decision-making regarding beach erosion management. [ABSTRACT FROM AUTHOR]