Komar, P.D. and Harris, E., 2022. Tectonic and climate-controlled hazards on the shores of Hawke's Bay, New Zealand. Journal of Coastal Research, 38(6), 1075–1095. Coconut Creek (Florida), ISSN 0749-0208.

Elevations of the Hawke's Bay shore on the Pacific coast of New Zealand were altered by an earthquake in 1931, such that at its north end the gravel beach and shore-front properties were raised by 2 m, while elevations dropped by 1 m at its south end. Along the elevated shore, the morphology was altered from a low-lying gravel spit that had experienced frequent overwash events, changed to a gravel barrier ridge where its increased stability permitted construction of expensive homes. The central stretch of shore, where there was minimal change in elevations, continues to experience wave overtopping during storms and high tides, just as had occurred prior to the earthquake. The southern-most shore, where subsidence took place, experiences substantial property damage during winter storms. With projections of accelerated rates of rising sea levels and increased storm intensities produced by global warming, concerns are that the developed shore of the elevated gravel ridge will again suffer from erosion and overwash flooding. Analyses have been undertaken of the hourly measured tides, waves, and calculated swash run-up levels on the beaches, combined to yield a record of hourly total water levels at the shore. Its extremes have been compared with the elevations of the surveyed gravel ridges to yield assessments of the potential erosion and flooding hazards. Still greater hazard assessments have been based on a recognition that the morphologies of the surveyed ridges provide direct evidence for the most extreme water levels that occurred at times of major storms in the distant past, prior to the availability of the process data. Assessments of hazards expected 100 years into the future have included projections of both rising sea levels and evidence for increasing storm-wave heights.

Pietrafesa, L.J.; Bao, S.; Gayes, P.T.; Carpenter, D.D., and Kowal, J.C., 2022. Variability and trends of the Florida current and implications for the future of the Gulf Stream. Journal of Coastal Research, 38(6), 1096–1103. Coconut Creek (Florida), ISSN 0749-0208.

The Gulf Stream, the North Atlantic Ocean Basin Western Boundary Current, plays a key role in moderating the climate of the North Atlantic Ocean Basin and surrounding landmasses. However, the Gulf Stream has been widely reported in the public media to be slowing down in its volumetric transport to the north, related to the reported weakening of the Atlantic Meridional Overturning Circulation. The recent exposé claims that the Gulf Stream may be in the throes of an irreversible collapse. This would have serious implications for the future climate of not only the United States, Canada, Greenland, Iceland, Scandinavia, the British Isles, and Europe, but for the entire planet, per se. In this study, investigations of the volumetric flux of the Florida Current took place that constitutes the formative beginning of the Gulf Stream at the Florida Straits to determine if there is evidence of a slowing of this major Western Boundary Current at the latitude of its beginning source. Findings include multiple, well-defined frequency and amplitude modulated internal modes of current variability in the 38-year record of Florida Current volumetric transport, ranging from weekly to monthly to seasonally to annually to interannually and decadal. The time series reveals an overall slowing of approximately 0.98×10⁶ meters³/second (equivalent to approximately one Sverdrup), or a 2.795% drop over the nearly four past decades of daily observations.

Yu, L.; Han, Z.; He, J., and Li, G., 2022. Experimental study on the permeability damage mechanism of gravel pack sand control medium in mud hydrate reservoirs. Journal of Coastal Research, 38(6), 1104–1115. Coconut Creek (Florida), ISSN 0749-0208.

The high argillaceous gas hydrate reservoir contains high silt and fine sand content. During the mining process, the fine silt sand will cause blockage of the gravel sand control medium, resulting in reduced medium permeability, that is, penetration damage. Penetration damage will reduce productivity and affect the long-term effectiveness of gravel. For the penetration damage problem of gravel sand control medium, the sand blocking simulation experiment of different reservoir water content, experimental pressure, and gravel specifications were carried out by self-developed sand blocking experiment system. A laser particle size analyzer and electron microscope were used to measure and observe the deposition of sand particles in the upper, middle, and lower layers of gravel layer after the sand retention experiment. The law of permeation damage and the mechanism of media permeation damage were summarized. The research results show that the blockage of sand control media can be divided into four stages: the beginning of blockage, the intensification of blockage, the dredging of blockage, and the balance of blockage. Reservoir water content, experimental pressure, and gravel size all influence permeability damage of gravel. The primary and secondary relationship of the influence of these factors on permeability damage is gravel size, experimental pressure, and reservoir water content. The pressure mainly affects the invasion depth of reservoir sand. The reservoir water content mainly affects the degree of permeability damage. The optimum particle size median ratio D₅₀/d₅₀ is about 25, and the medium has strong antipermeability damage ability and good sand retaining effect.

El Habti, M.Y.; Zayoun, A.; Zahra, S.F.; Raissouni, A., and El Arrim, A., 2022. Shoreline change analysis along the Tahaddart Coast (NW Morocco): A remote sensing and statistics-based approach. Journal of Coastal Research, 38(6), 1116–1127. Coconut Creek (Florida), ISSN 0749-0208.

The coastal areas are increasingly becoming vulnerable because of natural processes, such as climate change and sea-level change, or man-made effects. In Morocco, these areas are exposed to increasing risks and thus undergoing significant changes characterized by erosion or accretion of the shorelines. The following research outlines the changes for a shoreline length of approximately 17 km on the Tahaddart coast (NW of Morocco), based on an analysis of different shoreline rates. The latter was estimated by automatic analytical techniques using datasets of short and long-term aerial photos and satellite images (between 1972 and 2019) over 47 years. Remote sensing tools and GIS, with its extension digital shoreline analysis system, were used jointly for the evaluation of the shoreline changes during the period of the study. The approaches used in this research to assess the Tahaddart coast changes are the net shoreline movement, endpoint rate, linear regression rate, and weighted linear regression rate. These net rate changes of coastline have been calculated, also on three intervals of times (1972–81, 1981–97, 1997–2019). To facilitate the calculations, this study area was divided into four sectors to analyze Haouara Beach, the Tahaddart littoral spit, the Breich Beach, and the Oued Ghrifa estuary. The result shows that over a period of 47 years (1972 and 2019), more than 87% of the coast was eroded, whereas the remaining 13% endured accretion. This study emphasizes the challenges faced in representing coastline changes and reveals the intensity of the shoreline changes along the Tahaddart coast, which implies the setup and implementation of integrated management, effective environmental protection, and sustainable utilization of coastlines.

Huong, D.T.T. and Lan, T.D., 2022. Ecosystem sustainability assessment using an economic valuation index for selected offshore islands in Vietnam. Journal of Coastal Research, 38(6), 1128–1134. Coconut Creek (Florida), ISSN 0749-0208.

Two sites around Bach Long Vi Island (North Vietnam) and Tho Chu islands (South Vietnam) were selected to perform an economic valuation index analysis for the sustainability assessment of insular coastal ecosystems. The critical study methods are based on indicators and index selection and analyses following the well-documented Driver-Pressure-State-Impact-Response framework. Total ecosystem economic indices were proposed and calculated using three subindices, including the direct use value index (Idev) of a factor of 35.71 for Bach Long Vi Island and 9.52 for Tho Chu islands, the indirect use value index (Iidev) of 39.38 and 9.52, and the nonuse value index (Inuv) of 100 for both study sites. A total economic valuation index (Ieev) of island coastal ecosystems, consisting of coral reefs and rocky reefs at both sites, was calculated using Idev, Iidev, and Inuv. Ieev values at assigned scale between 0 and 100 points; values lower than 50 indicate ecosystems used unsustainably. Within this 100-point scale, the Ieev for the coastal ecosystems surrounding Bach Long Vi Island from 2014-detected parameters was calculated as 58.37, revealing an overall sustainable use. On the contrary, the value for the Tho Chu islands for the same period was 39.68, indicating that this latter site was unsustainably used. Developing and analyzing these indices can be applied to other coastal ecosystems, such as beaches, mangroves, corals, etc., both in Vietnam and in similar international contexts.

Mercaldi, B.; Brideau, L.E.; Tait, J.F., and Griggs, G., 2022. Seasonal morphological variability on estuarine beaches and implications for low-energy beach management. Journal of Coastal Research, 38(6), 1135–1147. Coconut Creek (Florida), ISSN 0749-0208.

Estuarine beaches and other low-energy shorelines are critical for habitats and coastal infrastructure protection. Many different species inhabit estuaries because of the water bodies' unique characteristics, such as their mixed seawater and freshwater and variable tidal ranges. Estuarine beaches also have the important role of buffering storm wave energy. Yet, their natural physical processes are understudied. This research focuses on seasonal morphological variability of estuarine, low-energy beaches and evaluates the implications for beach management practices. Five sandy beaches were studied along the northern shoreline of Long Island Sound in the northeastern region of the United States. The studied beaches vary in location, width, length, and orientation within Long Island Sound to represent different exposures to wave energy. Three seasonal profiles were measured at each beach approximately every four months from late 2015 to early 2019 to document topographic changes. The results revealed minimal sediment movement throughout the study period and there was no evidence of significant cyclic cross-shore sediment transport to indicate patterns of seasonal profile changes. These findings reveal important implications for beach management practices on low-energy shorelines. Specifically, estuarine and other low-energy beaches should be studied on decadal time scales to document any long-term variability and post-storm recovery rather than the monthly or yearly time scales on which open-ocean beaches are typically evaluated. Additionally, estuarine beaches and other low-energy shorelines require specialized management practices that cater to their stagnancy to ensure adequate protection of coastal structures and infrastructure in the face of intensifying hurricanes and sea level rise.

Zhang, C.; Gao, L.; Lu, Z.; Liu, H.; Zhu, H., and Tang, K., 2022. Classification of aquaculture waters through remote sensing on the basis of a time-series water index. Journal of Coastal Research, 38(6), 1148–1162. Coconut Creek (Florida), ISSN 0749-0208.

Accurate spatial distribution information on aquaculture is crucial for scientific aquaculture management, postdisaster evaluation, and water environment protection. At present, large-scale aquaculture areas can be quickly and accurately monitored using remote-sensing technology. However, most previous studies gave importance only to extracting aquaculture areas and ignored the classification of aquiculture types. Although several researchers classified aquaculture modes, the waters in aquaculture areas were unclassified. Moreover, classification of the aquaculture target is usually performed on a single remote-sensing image, which lacks time-series information. To examine existing issues, the current study selected the coastal marine aquaculture areas in the southern Lvushunkou District of Dalian. First, a normalized difference aquaculture water index (NDAWI) was constructed on the basis of the measured data through a spectral feature analysis. Second, NDAWI was extracted from Sentinel-2 images to construct a time-series data set, and the random forest classification method was applied to classify kelp and wakame aquaculture waters. Last, the experimental outcomes of the NDAWI data set were compared with those of other time-series data sets. Results showed that the overall accuracy of the NDAWI time-series data set was 92.11%, which showed an improvement of 7.68%, 17.66%, 4.50%, and 11.50% compared with the values for normalized difference chlorophyll index, normalized difference vegetation index, and greenness component of tasseled cap transformation data sets and single-phase images, respectively. The NDAWI time-series data set constructed in this study exhibited a dramatically improved classification accuracy compared with other time-series data sets. It has a high application value for identifying relevant aquaculture areas.

Zhou, J.; Sun, P., and Pan, L., 2022. Modal analysis of the wake instabilities of a propeller operating in coastal environments. Journal of Coastal Research, 38(6), 1163–1171. Coconut Creek (Florida), ISSN 0749-0208.

The dynamic characteristics of propeller wakes are a function of hydrodynamics, noise propagation, and structural vibration, among other factors. The evolution of propeller wake flow mechanisms from the near field to the far field has always been a significant topic of turbulence research. Numerical simulations of propeller wakes under different loading conditions were conducted using the improved delayed-detached eddy simulation (IDDES) method. Based on the mode decomposition technique, the results of numerical simulations were used as the input data to perform a reduced-order analysis of propeller wake fields. The results showed that there is a considerable difference between the morphology characteristics of propeller wakes under high and low loading conditions, where the former tends to be unstable earlier in the evolution. According to the mode decomposition results, with decreasing mode frequency, there is strong circumferential diffusion in the tip vortices, which is more pronounced under the high loading condition and at locations further downstream. Circumferential diffusion is a key factor triggering the propeller wake to change from the stable to the unstable state. The present work can provide a significant reference for the design and optimization of next-generation marine propellers operating behind vessels sailing in both coastal and offshore environments.

Ribeiro, V.V.; Póvoa, A.A.; De-la-Torre, G.E., and Castro, Í.B., 2022. Indexing anthropogenic litter as a contamination gradient from rivers to beaches in southeast Brazil. Journal of Coastal Research, 38(6), 1172–1180. Coconut Creek (Florida), ISSN 0749-0208.

Rivers are important contributors to marine anthropogenic litter (AL), but riparian vegetation remains to date poorly investigated. Brazilian AL study procedures are unstandardized while overlooking sources and river contributions. Boiçucanga is located in a highly visited Brazilian city, with an urban gradient from a river stream towards the beach between a state park and a marine protected area. This study used a multi-indexing approach to assess sources, distribution, and composition of AL at Boiçucanga riparian forest and beach locations. Cigarette butts (CBs) and smoking were the most common AL composition and source, following the urban gradient. CBs leak pollutants, representing a hazardous form of AL. Despite being very clean, AL was found in all sites, showing a level of threat to this highly environmentally vulnerable area. Personal protective equipment items related to the coronavirus disease 2019 (COVID-19) pandemic are becoming a ubiquitous issue worldwide, representing 0.8% of AL in this study. These study results provide a better understanding of the multiple variables influencing AL contamination in riparian ecosystems and beaches.

Lu, Y.; Shao, W.; Chang, X.; Chuang, Z., and Zhou, Z., 2022. Analyzing wind direction flow control on full-scale amphibious assault ship airwakes using a computational fluid dynamics simulation. Journal of Coastal Research, 38(6), 1181–1194. Coconut Creek (Florida), ISSN 0749-0208.

This paper presents an aerodynamic study on flow control by different wind directions on full-scale amphibious assault ship (AAS) airwakes using computational fluid dynamics (CFD). The Reynolds-averaged Navier-Stokes (RANS) equation was employed to conduct a numerical simulation for the analysis of aerodynamic characteristics of the ship airwake flowfields under wind impacting. The aerodynamic performance of a small-scale landing helicopter assault (LHA) model was first simulated and then validated with Particle Image Velocimetry experimental data from the VSHAIP project of the NASA Ames Research Center. Employing CFD simulations, the computed unsteady ship airwakes compared well to experimental data. After validation, full-scale AAS airwakes were further simulated by CFD to capture the vortex patterns and velocity distributions of winds in the Head, Red, and Green directions surrounding the AAS. Building on this, the range of wind direction angles of relatively stable vertical wind speed above each landing point is discussed. The aerodynamic analysis and numerical method described in this study will build a strong foundation supporting the numerical simulation of the ship airwakes in full scale as well as small scale.

Yao, Y.; Zheng, R., and Parmak, M., 2022. Using an evaluation index system to examine the developmental potential of yachting tourism. Journal of Coastal Research, 38(6), 1195–1206. Coconut Creek (Florida), ISSN 0749-0208.

The quantitative measurement and comparison of the development potential of yachting tourism to determine its development type are greatly significant to the reasonable planning and development of the yachting tourism industry. This study constructs an evaluation index system comprising elements, such as yachting tourism destination, source-market, travel, and support systems, to examine the development potential of yachting tourism. Further, the evaluation system comprehensively employs the analytic hierarchy process, as well as the entropy and cluster analysis methods, to empirically evaluate the tourism development potentials of 84 marinas in 29 coastal cities in China. The results demonstrate that the destination system comprising natural and scenic resource endowments and commercial basic conditions accounts for the core elements of regional yachting tourism development. The high potential of the marinas for yachting tourism mainly derives from the superior regional tourist market, traffic conditions, and the yacht industry foundation. Furthermore, regional development strategies comprising four potential types are also discussed to improve the competitiveness and attractiveness of yachting tourism.

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.

Stalter, R. and Lonard, R.I., 2022. Biological flora of coastal wetlands: Sporobolus spartinus (Trin.) P.M. Peterson & Saarela. Journal of Coastal Research, 38(6), 1231–1235. Coconut Creek (Florida), ISSN 0749-0208.

Sporobolus spartinus (Trin.) P.M. Peterson & Saarela = Spartina spartinae (Trin.) Merr. ex Hitchc. is a New World temperate, subtropical, and tropical wetland species that often forms monotypic stands in intermittently flooded brackish marshes or in saline prairies that are flooded periodically. It is a densely cespitose perennial that tolerates salinities ranging from 3.5 to 44 psu. The water table at these sites is 10 to 30 cm below the surface and can be flooded up to 14 cm above the soil surface. Also known as gulf cordgrass or sacahuista, its extensive fibrous root system makes this species an excellent choice to prevent erosion and to protect the land from storm surges. The southern cordgrass community provides habitats for endangered whooping cranes and ocelots in Texas and habitats for Lower Keys marsh rabbits in Florida.

Murphy, K.A.; Zawada, D.G., and Yates, K.K., 2022. Subsampling large-scale digital elevation models to expedite geospatial analyses in coastal regions. Journal of Coastal Research, 38(6), 1236–1245. Coconut Creek (Florida), ISSN 0749-0208.

Large-area, high-resolution digital elevation models (DEMs) created from light detection and ranging (LIDAR) and/or multibeam echosounder data sets are commonly used in many scientific disciplines. These DEMs can span thousands of square kilometers, typically with a spatial resolution of 1 m or finer, and can be difficult to process and analyze without specialized computers and software. Such DEMs often can be subsampled to expedite analysis with negligible impact on results for large-scale geospatial analyses. Subsampling can be achieved by creating a grid of points that specify the locations from which to extract elevation values from the DEM. This paper presents a method that can be used to accurately perform subsampling of large-scale, high-resolution DEMs using GIS software. This subsampling method was applied to two LIDAR-derived DEMs encompassing 242 km² of the northern Florida Reef Tract as an example application and to test subsampling accuracy. Results indicate that subsampling 1-m-resolution DEMs using a 2-m-spaced grid results in no significant difference in mean elevation or other basic statistics for analyses performed over multiple spatial scales ranging from 1 km² to 242 km².