Beaches worldwide play an essential role in shore protection under storm conditions. How to identify the threshold beach width for effective shore protection remains largely unresolved due to a scarcity of measured beach profiles with sufficient temporal and spatial resolutions. In this study, weekly to monthly surveys spaced 100 m along the shoreline have been conducted at Ortley Beach, New Jersey since Fall 2023. The survey covered beach changes induced by Hurricane Lee and Tropical Storm Ophelia in Fall 2023. About half of the lost beach volume recovered within 1–2 weeks after the passage of these storms. With the onset of winter, cold fronts caused significant longshore variations in beach/dune erosion. At the erosional hotspots, severe dune line retreat occurred where the dry beach was narrower. Results indicate a critical threshold of dry beach width of about 35 m, below which dune-line retreat becomes more likely, increasing risks to landward infrastructure. As the weather shifted to summer of 2024, the beach gradually recovered, but net shoreline erosion and beach volume loss persisted, which created a more vulnerable condition for the following winter until the renourishment in Spring 2025. A simple empirical equation for threshold beach width was developed by integrating grain size and offshore wave height, supplemented by long-term beach-profile measurements from North Sand Key along the west-central Florida coast. Accurate estimation of this threshold provides a useful indicator for emergency beach management during storm conditions.

Alaska, the largest geographic state in the United States, experiences climate change and global warming two to three times that of the global average, leading to thawing permafrost, wildfires, and more severe storms. However, managing climate interventions in Alaska is riddled with challenges that threaten to create risk–risk tradeoffs. Based on semi-structured expert interviews ( N = 24), site visits in Alaska ( N = 3), and photography, including within one Indigenous group in the Arctic Circle, this study investigates the concept of risk–risk tradeoffs involved in Arctic climate interventions. It does so by examining two case studies: one of a $360 million plan for coastal protection and adaptation via seawalls, revetments, and beach nourishment in Utqiagvik (formerly Barrow), as well as another case study of plans to expand the management of Alaskan boreal forests across the Tanana Valley and Matanuska-Susitna Valley to provide about $50 million worth of carbon removal services. The study explores how climate protection interventions have a target risk to be mitigated—such as flooding, storm surge, coastal erosion, accelerated global warming—but also involve adverse or countervailing risks such as permafrost thawing, sea level rise, inward human migration, wildfires, invasive species, and insect outbreaks. The study then discusses implications of these results in terms of differential risk dynamics, intersecting risks, and uncertainty. In doing so, it reveals a recurring and capricious challenge in terms of climate policy, climate protection, and risk management. It highlights creative adaptation of local policy instruments to combat climate change, and illustrates the value of engagement with non-governmental entities to fortify policy measures.

Beach nourishment has become a globally adopted “soft” engineering measure to mitigate coastal erosion and sustain beach functions. This study conducts a systematic comparative analysis of beach nourishment practices between China and the United States, focusing on extensive project data and historical records. The research examines differences in historical development trajectories, spatial distribution patterns, restoration philosophies, funding mechanisms, and key technologies. The results reveal that the U.S., with over a century of experience, exhibits large-scale, high-frequency nourishment projects supported by diversified funding and long-term maintenance strategies. In contrast, China, despite a later start (circa 1992), has achieved rapid progress in both project scale and technical innovation, though its approach remains more government-led and structurally oriented. This study also identifies converging trends in resource concentration between the two countries, as measured by a proposed “beach nourishment primacy” index. Based on these findings, the work offers strategic recommendations for the coastal management of China, including the establishment of a national nourishment database, adoption of Regional Sediment Management, and greater integration of ecological engineering principles. This comparative analysis provides valuable insights for coastal nations seeking to optimize beach nourishment strategies in the face of growing climatic and anthropogenic pressures; to further advance these efforts, future research could explore the integration of interdisciplinary approaches and intelligent technologies, aiming to deepen our understanding of coastal system complexity and support the development of dynamic adaptive management.

A new and more accurate overfill ratio for beach nourishments and its comparison with James' RA

The Muttukadu to Mahabalipuram coastal stretch in Tamil Nadu represents a geomorphologically diverse 23 km coastal corridor transitioning from urban Chennai environs to heritage coastline. This study presents comprehensive textural and heavy mineral analysis of 20 systematically collected shoreline sediments to determine provenance, transport mechanisms, and coastal dynamics. Grain size analysis using Folk and Ward statistical parameters reveals predominantly medium sand (95% of samples) with moderate to well sorting, indicating stable beach environments with saltation-dominated transport mechanisms. Spatial textural variations demonstrate distinct energy zones, with sorting coefficients ranging from 0.442φ to 1.013φ and skewness patterns indicating net southward longshore transport. Heavy mineral analysis of 23 mineral species reveals significant spatial zonation with three distinct sedimentological provinces. The northern section exhibits magnetite-dominated assemblages (85-92%), indicating derivation from Deccan Trap-related mafic sources, while the central-southern section features garnet-rich assemblages (68-83%) derived from Eastern Ghats metamorphic rocks. Multivariate statistical analysis confirms this zonation, with hierarchical clustering and PCA identifying clear provincial boundaries. ZTR maturity indices vary from 0.02 to 0.47, reflecting differential weathering and transport distances. The study establishes crucial baseline data supporting UN Sustainable Development Goals (SDG 11, 13, 14). Heavy mineral concentration patterns inform resource management strategies, while textural analysis provides essential data for coastal engineering and beach nourishment projects. Sediment transport pathway identification supports sustainable coastal development in this urban-heritage transition zone. Results demonstrate integrated sedimentological approaches efficacy for coastal zone management and provide a methodological framework applicable to similar crystalline coastlines globally.

Coastal erosion in Tra Vinh province and the Mekong Delta region is becoming increasingly severe due to various factors, among which hydrodynamic conditions (tides, waves, river, and sea currents) play a crucial role. This study utilizes the MIKE 21/3 Coupled Model FM to assess the effectiveness of two coastal protection scheme options for the coastal area of Hiep Thanh commune, Tra Vinh: reinforced concrete revetment (Option 1) and hybrid revetment (trees branch fences, geotube bags, and perforated breakwater – Option 2). The results indicate that Option 1 provides better protection for the existing shoreline. However, Option 2 demonstrates superior performance in wave attenuation and beach nourishment, with the ability to reduce wave height approaching the shore by up to 70%. Option 2 also contributes to erosion reduction and shoreline lowering during the Northeast monsoon season (high water levels and strong waves). This study provides a scientific basis for selecting a suitable coastal protection scheme for the Hiep Thanh commune and can serve as a reference for areas with similar natural conditions. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

Viability of Beach Nourishment as a long-term Strategy for Maintaining Beaches in Bays and Estuaries

Sea turtle survival rate and hatchling sex ratios are closely linked to incubation temperature and duration, both of which are critical for understanding species resilience to climate change. This is particularly important for sea turtles currently nesting in thermally stressed environments, such as the North West Indian Ocean green sea turtle population. However, there is a methodological discrepancy between field studies (which usually measure incubation duration from oviposition to emergence) and constant temperature incubation studies (which measure from oviposition to either pipping or hatching time). The period between hatching and emergence can span several days, potentially affecting estimates of the thermosensitive period (TSP) when sex is determined. This study investigates the often-overlooked interval between hatching and emergence, a developmental phase essential in hatchling survival. We evaluate two non-invasive methods to estimate this interval: (1) deploying tri-axial accelerometers and temperature loggers to detect movement associated with hatching, and (2) comparing laboratory and field incubation durations using fitted models. Results reveal that field-based durations consistently exceed laboratory-based predictions, primarily due to the inclusion of the emergence to pipping time. Across seven nests, using emergence instead of pipping to mark the end of incubation raised mean TSP temperature by 0.1-0.5°C and lengthened the inferred TSP by about four days. Our findings highlight the implications of this discrepancy for modelling TSP timing; by excluding the pipping to emergence time. While this bias may seem minor, the narrow thermal range of sex determination means it could significantly skew sex ratios and lead to artificial feminisation estimations. By refining incubation duration metrics, this work enhances the accuracy of sex ratio predictions and provides new insights into the hidden pipping dynamics informing conservation strategies such as beach nourishment and hatchery practices.

Drowning in sand: Examining the effects of beach nourishment on subtidal benthic macrofauna in southeast Florida

This study addresses the longevity of beach nourishment in a high-energy coastal environment. It focuses on a site along the Northern Portuguese Atlantic coast, characterized by intense littoral drift, in the order of 1 million m3 and N–S oriented. The region undergoes an erosion process, and some localities are protected by groynes and frontal defense structures. The longevity of beach nourishment is evaluated through a coastline evolution model (previously calibrated and validated), compared for three scenarios: the absence of nourishment, i.e., the “do nothing” scenario; a (one-shot) 4 million m3 of sand nourishment intervention; and a detached breakwater combined with nourishment. The recent morphological evolution of the study site is evaluated through the results of a four-year (2018–2021) topobathymetric monitoring program implemented by the Portuguese Environment Agency. The lifespan of the nourishment ranges from 4.5 to 7.5 years. While the detached breakwater significantly increases the beach width to the north, it also exacerbates sediment loss to the south, regardless of its position. However, after 10 years, the cumulative sediment balance for the combined scenario closely mirrors that of the nourishment-only approach. The discussion of these results includes reflections on the longer-term impacts of using coarser sediments (relative to native material) on coastline evolution and on the influence of the breakwater’s layout on nourishment longevity.

As global warming and the greenhouse effect become increasingly evident, and in response to the “Carbon Peak” and “Carbon Neutrality” policies, extensive research has been conducted on “blue carbon” sinks in marine and coastal zones. Due to their low cost and flexibility, hydro-eco coupled numerical modeling has emerged as a prominent method for studying carbon sequestration. This study employs a two-dimensional NPZD (Nutrient-Phytoplankton-Zooplankton-Detritus) framework coupled with tidal flow dynamics to analyze changes in flow fields, ecological benefits, and carbon sequestration effects before and after the restoration project in Sanya Bay. Additionally, the impact of planting seagrass seedlings near the artificial island on carbon sequestration is investigated. The seagrass restoration achieved approximately 0.57 Mg C sequestration within one month. The project has achieved remarkable benefits. According to different working condition examples, the annual carbon sink of the artificial island and the sand replenishment restoration has increased by 83.83 Mg compared with that before the restoration.

A scientific expert elicitation was conducted to address the feasibility of restoring coastal environments in response to future hazards to best meet management objectives. Subject matter experts produced probabilistic estimates of coastal change metrics used to evaluate decision objectives and alternatives informed by a stakeholder advisory group. Changes in salt marsh extents, storm surge flooding and barrier island morphology by the year 2050 were estimated for three scenarios of management actions (no action, interior headland restoration, beach and dune nourishment), while also considering the effects of future sea level rise (SLR). Collectively the participants were confident in their expectations of increased storm surge flooding with SLR, regardless of management interventions. Estimates of marsh response had large uncertainty, but experts generally hypothesized that marsh area would decrease with increasing SLR if no action was taken, especially in areas already experiencing marsh deterioration. There was agreement that dune heights and barrier island widths would decrease with SLR if no action was taken. Experts felt that beach and dune nourishment may reduce the amount of erosion under future SLR. All experts recognized the dynamic effects of SLR and feedback between bio-geo-physical processes that govern coastal systems. Participants agreed that size and location of management actions were important factors for influencing the coastal response. Expert elicitation is novel in the context of coastal management decision making and can be a useful tool for informing future scientific needs and providing rapid results to end users to inform reallocation of resources surrounding research and application.

Beach nourishment on low-energy coasts: Purpose and persistence (Puck Lagoon, Poland)

Abstract Dredging is a crucial process for the maintenance and management of aquatic ecosystems, involving the removal of sediment that accumulates in bodies of water such as rivers, lakes, and dams. Specialized dredging equipment operates using vacuum mechanisms to efficiently extract and transport sediment, thus ensuring navigational and ecological integrity. In tropical regions, extreme precipitation exacerbates sediment influx, diminishing reservoir capacity and impacting agricultural irrigation and hydroelectric generation. Furthermore, sediment accumulation can lead to nutrient loading and harmful algal blooms. Over time, sedimentation can lead to significant issues, including reduced water depth and impaired water quality, affecting both aquatic life and human activities reliant on these waterways. Effective dredging not only addresses sediment buildup but also repurposes extracted materials for various applications, including beach nourishment and construction fill. Various methods of sediment removal, including mechanical and hydraulic techniques, are employed based on project needs and environmental conditions. Mechanical dredging utilizes equipment like grabs and clamshells, while hydraulic methods leverage suction and cutting technologies. Choosing the appropriate method involves careful consideration of site-specific factors, ensuring operational efficiency and minimal ecological impact. Ultimately, dredging plays a vital role in sustaining healthy aquatic environments while supporting essential economic activities.

The soundscape of a given location can be transformed over time due to factors such as urbanization, technological advances and social changes, among others. The main tourist attraction in Natal-RN, Brazil, Ponta Negra beach, has undergone extensive intervention to contain the effects of erosion caused by the advance of the sea. The beach has had its sand strip expanded, now reaching about 100 meters at low tide. This work has had a major environmental impact, also affecting the soundscape. The aim of this article is to assess the impact of the Ponta Negra beach renourishment project on users' perceptions of the soundscape. The methodology was based on Sound Pressure Level measurements, vehicle counts and questionnaires with local users before and after the construction work. The number of measurement points after the work had to be increased due to the widening of the sand strip. The results show that, after the construction work, the sound of the sea became more distant for passers-by on the promenade, and the urban sounds of the nearby traffic lane became more prominent. In addition, there were more scenes of different human activities, such as soccer and volleyball games, which consequently changed the soundscape.

Effective sand nourishment for beach regeneration requires selecting sediments from a borrow zone compatible with the native materials, ensuring their stability and longevity. In Cuba, most of its beaches are predominantly covered by biogenic-marine sediments, and assessing the suitability of borrow sand presents unique challenges. This article compares two methods for assessing sand suitability in Cuba, where biogenic-marine sediments predominate: the Stability Index (Si) method and the traditional approach proposed in the Shore Protection Manual, herein referred to as the Overfill Factor (Ra) method. The Si method assesses compatibility by comparing grain-size distributions without assuming log-normality, while the latter uses the statistical parameter to estimate overfill requirements. The purpose of this study was then to provide a first assessment on this topic by evaluating a method that possibly allows for better adjustment than traditional methods, with the case studies on the beaches in Cuba specifically covered by biogenic-marine sediments. Using real-life case studies of artificial sand nourishment projects on beaches in this geographic region with varied sedimentary characteristics, we determined the performance of both Si and Ra methods in classifying borrow materials. The results of this initial approach suggest that the Si method offers greater flexibility when evaluating borrow zones, providing more accurate results and the possibility of utilizing areas that would have been discarded by conventional methods. The possibility of more efficient use of natural and economic resources is also becoming evident. Furthermore, it indicates that the application of Si is feasible in subsequent artificial sand replenishment projects in Cuba and on similar beaches with biogenic-marine sediments in the Caribbean region. This study represents the first application of a specific methodology to be applied for evaluation of the suitability of sand for Cuban projects, with the aim of its introduction as an additional tool for future studies.

Coastal erosion at Kuta Beach, Bali, represents an increasingly intense and complex ecological crisis resulting from a combination of natural factors and human activities. The degradation of the shoreline not only impacts public infrastructure but also threatens the sustainability of social, cultural, and economic spaces of coastal communities. Previous mitigation efforts, such as beach nourishment and the construction of breakwaters, have shown limited effectiveness and have not been accompanied by community-based or adaptive technological approaches. This study aims to evaluate past responses and develop participatory and sustainable intervention strategies. Using a descriptive qualitative approach, data were obtained through literature review, field observation, and interpretation of scientific sources. The findings reveal that addressing coastal erosion at Kuta Beach requires a collaborative action model that is not only technically driven but also strengthens disaster communication systems, public education, and tourism-friendly technologies. The proposed recommendation is the KUTA COASTAL GUARD program, which integrates technical actions, socio-cultural engagement, environmental literacy, and citizen-based monitoring. Technological supports such as the SISI application, Submerged Pneumatic Barrier, and Reef Ball are also identified as potential solutions to preserve the ecological and recreational functions of the beach. This study highlights the importance of shifting from reactive approaches toward adaptive, cross-sectoral, and replicable crisis management for other coastal areas.

Sediment size is an important characteristic of beach and dune systems and is linked to beach stability, slope, breaker type, and habitat suitability among other important characteristics. Existing literature is sparse with comprehensive sediment characterizations over statewide spatial scales. Often, sediment size is determined on an “as needed” project basis and is rarely cataloged. Herein, an extensive analysis of grain size at New Jersey beaches is presented and compared with two sets of historical data from 1950 and 2011. Sediment samples are collected at 171 profiles along New Jersey’s 210-km-long coastline during the summer of 2023 and spring 2024. Based on the data collected, a statewide average median grain size of 0.49 mm is obtained. Geographically, larger sediments are found along the northern New Jersey coast and finer sediments are found along the southern coast. Sorting mechanisms associated with nodal points in longshore sediment transport and tidal inlets have more localized effects. When compared to historical data sets collected in 1950 and 2011, grain sizes are found to be larger, nearly doubling in some locations. Beach nourishment is one of the factors thought to influence this trend.

A framework to mitigate aeolian erosion on nourished beaches

Long-distance transport is a typical characteristic of severe dust storms. As an important dust source and ecological security barrier for the Beijing-Tianjin-Hebei region, analyzing the origin and transport characteristics of dust storms passing through the Hunshandake Sandy Land is of great significance. This study utilized remote sensing and reanalysis data to analyze a severe dust storm process from March 19-24, 2023, and its associated weather systems. The WRF-Chem and LAGRANTO models were further employed to analyze the vertical dust concentration distribution and dust transport trajectories at different altitudes as the dust storm passed through the Hunshandake Sandy Land. The results indicate: (1) The dust storm originated from the Taklimakan Desert and western Mongolia, spreading eastward under the influence of a developing Mongolian cyclone. When passing through the Hunshandak Desert, it was affected by the superposition of locally generated sand and upstream transported sand and dust, resulting in a significant increase in dust concentration. Subsequently, it continued to affect regions such as North China, Northeast China, and Beijing Tianjin Hebei. The Mongolian cyclone dominated this process, and the 500 hPa trough ridge structure and the southward movement of high-altitude cold air provided key dynamic conditions. The development of surface low pressure and the Mongolian cyclone further promoted the sand and dust generation and transport. (2) During transport, dust concentrations were jointly influenced by dynamic uplift, vertical diffusion, and gravitational settling. The peak concentration occurred around 12: 00, reaching a vertical height of 650 hPa (approximately 3, 500 meters) , after which it gradually stratified and stabilized. The highest concentration was near the surface. Although the concentration in the middle layer decreased slightly, it remained relatively high. The concentration in the upper layer was lower, but driven by large-scale circulation and upper-level jets, it underwent long-distance transport northeastward. As a key transmission node, the Hunshandake Desert has strengthened the concentration of sand and dust and maintained its long-distance transport capacity through local sand replenishment and dynamic uplift. These findings provide valuable references for dust control in the Hunshandake Sandy Land and cross-border dust prevention collaboration between China and Mongolia.