Ocean surface waves are strongly affected by various physical processes, leading to the formation of gravity waves propagating from offshore toward coastal areas. The interaction between these waves and submerged structures presents critical challenges in ocean engineering. This study presents an analytical investigation of surface wave interaction with a single submerged rectangular trench in the presence of a uniform current, which may be co-directional or counter-directional with respect to the direction of wave propagation.

The wave dynamics are analyzed within the framework of linear potential flow theory, assuming an incompressible, inviscid, and irrotational fluid. The analytical model is based on the evanescent mode expansion technique, which allows the representation of the velocity potential as a series of propagating and decaying modes. Boundary conditions are rigorously applied at the free surface, trench interfaces, and channel bottom. The method ensures continuity of potential and velocity across trench boundaries, accounting for the influence of current on dispersion relations.

The results show that the presence and direction of the current significantly modify the wave reflection characteristics. The trench geometry, including depth and width, also has a substantial impact on the reflection and transmission behavior. The study confirms the ability of evanescent mode theory to capture complex interactions in wave–structure systems more accurately than simpler approximations.

This work enhances the understanding of wave attenuation mechanisms due to submerged structures and supports the development of efficient analytical models for coastal protection. The findings provide guidance for future experimental validation and practical applications in marine and coastal engineering.

Recent tsunami-related studies have employed numerical simulations to estimate inundation areas and integrated these results with geospatial demographic data to determine the number of potentially affected individuals. While this methodology is useful for estimating economic losses, particularly for real estate, it often overlooks evacuation dynamics that significantly influence casualty estimations.

Evacuation modeling frequently relies on computationally intensive techniques, such as agent-based models (ABMs), to simulate human movement. In this study, we propose a simplified evacuation model that estimates a hypothetical location for population groups, defined by census blocks within the affected area. This model integrates geospatial road network data to better approximate feasible evacuation routes, improving spatial realism while drastically reducing processing time and storage requirements.

Tsunami inundation scenarios were analyzed using the TUNAMI-N2 numerical model for multiple seismic sources along the Central Peru subduction zone, obtaining maps of inundation depths and arrival times. The population was categorized into three age groups, each with differentiated displacement capacities, and assigned hypothetical shelter points based on proximity and access through the local road network.

The simplified approach enabled estimating the quantity of people affected, injured, and fatalities. Additionally, the variation of these statistics for different parameters, such as displacement velocity and response time, was analyzed. The proposed model provides an efficient and scalable tool for coastal cities, offering valuable insights to support decision-making processes in Disaster Risk Reduction (DRR).

Located at the intersection of land, sea and the air, shoreline is an indispensable parameter for coastal erosion and coastal vulnerability studies. It is well known that the shoreline position is subjected to longshore and cross-shore sediment transports. Such dynamics are typically observed during the winter and summer seasons mainly due to the action of the waves and currents and consequently affect the coast and the beach's morphologies. However, not all the beaches and the coasts respond to these processes the same way. A recent study indicated that wave conditions and physical settings of the beaches are adequately diverse to adapt to regular seasonal cycles of erosion and accretion. Our study intends to investigate the governing processes involved in morphological changes of the highly dynamic sandy beach located on the Capo Peloro Peninsula, Sicily. Four-month daily observations were conducted using remote sensing imagery and fieldwork surveys. Sentinel-2 satellite images acquired in September, October, November and December 2024 were analyzed to extract information related to the shoreline positions. The images were obtained from the Copernicus data space ecosystem. The feature extraction methodological approach was performed using image segmentation to obtain time-series shoreline vector files. Furthermore, the digital shoreline analysis system (DSAS) was used for shoreline statistical change calculations. For the same period, in situ geomorphological analysis was conducted for the estimation and interpretation of horizontal and vertical beach behaviors. The results obtained suggest that Capo Peloro beach respects the classic winter erosion and summer accretion cycles with smaller waves moving beach materials inland during the summer, with larger waves causing the movement of the beach material offshore during the winter season. In addition, we observed longshore beach material transportation due to the alternative NE-SW and NW-SW wave actions. It is important to note that this beach is located on the junction of Tyrrhenian and Ionian seas with different water densities and temperatures, which play a role in the persistence and duration of wave direction and wave power resulting in long-term configuration of the beach morphology.

The current study seeks to improve beach nourishment operations by proposing a methodological monitoring approach aiming at identifying and excavating the sediment needed for such operations. Here, we propose the nearshore morphological change assessment approach as a tool for the coastal monitoring and protection remediations. Such a tool would help policy makers and scientists working to find solutions and mitigate the impacts of climate in coastal and low-lying areas. This study was conducted on the beach of San Montano located on the Island of Ischia in the Gulf of Naples; this area has been subject to processes of erosion and accretion recorded for the last 50 years. In addition, meteo-marine events observed in this area have increased coastal erosion processes. However, given the fact that this area is a naturally semi-protected beach, previous studies have indicated that the natural and anthropological events did contribute to the total loss of sediments far from the shoreline. In this case, morphological and hydrodynamic analyses would help to monitor and reuse the sediment involved in nourishment processes. Four topo-bathymetry surveys were conducted using a single-beam echosounder and GPS; in addition bottom sea current measurements were conducted to evaluate morphological variations of the submerged and emerged beaches. The results indicate that the sediments have been deposited in the shallow water of about 4 to 6 meters. In addition, the results obtained from the analyses of the direction and the velocity of the bottom sea current indicate that the distribution of the sediments used for the beach nourishment can be estimated with high precision. The overall results indicate that the proposed monitoring methodological approach would be a resilient and cost-effective strategy for the mitigation of the impact of coastal erosion.

Tropical cyclones, even without making direct landfall, can generate severe coastal inundation through multiple mechanisms. These events are increasingly recognized as critical hazards for Vietnam’s central coast, where narrow continental shelves and complex coastal topography amplify hydrodynamic responses. This study examines several historical tropical cyclones, including Typhoon Rai (2021), which caused significant flooding in parts of Vietnam’s central coast. Using meteorological reanalysis and tide-gauge records, we quantified water-level anomalies and identified the dominant forcing mechanisms. Results indicate that inundation during these events was not primarily controlled by pressure-driven storm surge but rather by the combined effects of low-frequency waves, wind setup, and local bathymetric amplification. The findings highlight that non-landfalling storms represent a significant yet underappreciated coastal flood hazard for Vietnam. Conventional early warning systems, which often focus on landfalling tracks, may underestimate inundation risk when storms remain offshore but retain strong intensity. Incorporating offshore storm scenarios, wave–surge coupling, and site-specific geomorphological factors into forecasting frameworks will improve predictive skill and strengthen coastal resilience. This research enhances understanding of the impacts of non-landfalling tropical cyclones in the context of coastal engineering and disaster preparedness, providing a scientific foundation for improved early warning strategies and adaptive coastal management in Vietnam and other cyclone-prone regions with similar geomorphic settings.

Coastal erosion represents a major challenge for shoreline management globally, with beach nourishment being the most widespread mitigation strategy. The effectiveness and longevity of these projects critically depend on the granulometric compatibility between borrow and native sediments, requiring a precise characterization of both materials.
However, the characterization of borrow sediment is influenced by a set of factors during the analysis procedure that can introduce considerable uncertainty into the results. Essential variables such as the sampling technique, sediment variability within the dredge hopper, sieving specifications (e.g., column diameter and sieving time), and the sample drying method have been shown to have a substantial quantitative impact on the final findings.
This work presents a comprehensive review of research quantifying the influence of these factors on the accuracy of granulometric analysis. The magnitude of the cumulative error is assessed, demonstrating how minor procedural inconsistencies can lead to significant deviations in key sediment parameters like mean grain size and sorting. Such deviations have direct implications for calculating the required nourishment volume, resulting in significant errors in the estimated quantity. These miscalculations directly compromise the economic viability of the project by creating a critical mismatch between the designed and the truly necessary sand volume. In response, standardized protocols are proposed to mitigate these uncertainties and enhance the predictability and effectiveness of future nourishment interventions.

Coastal zones, long favored for fertile lands, trade, and mild climates, are now highly exposed to climate change impacts, particularly sea-level rise (SLR) scenarios and erosion. By 2060, global low-elevation areas may host over one billion people, facing growing flood risks. Regional sea level is influenced by climatic drivers, tectonics, isostatic adjustments, and circulation. In particular, in the Mediterranean, land subsidence and global warming intensify hazards, threatening infrastructure and heritage. This study examines future SLR along the Northern Tuscany coast, between Pisa and Massa-Carrara, to support adaptation strategies.

A multidisciplinary study was launched to project local SLR and generate flood maps up to 2150 using sea-level data from local stations (PSMSL; ISPRA) and vertical land motion as derived from GNSS networks and MT-InSAR data analysis. High-resolution LiDAR topography (2008–2010), referenced to the ITALGEO 2005 geoid, supported inundation mapping. Results were combined with IPCC-AR6 projections under the high-emission SSP5-8.5 scenario. Local subsidence was considered, assuming no major tectonic or volcanic events.

By 2150, under SSP5-8.5, sea levels along the Northern Tuscany coast (465km²) could rise up to 1.5m, flooding 170.7km². Estimates were obtained using a passive approach, where land below the projected water level is considered inundated, regardless of direct sea connection.

The results highlight the vulnerability of Northern Tuscany’s infrastructure and settlements. They stress the need for proactive planning, stronger coastal defenses, and integration of climate risk into development policies. Interdisciplinary collaboration among scientists, planners, and policymakers is essential for resilient and sustainable coastal management under future SLR.

Wave overtopping and flooding hazards represent critical issues for coastal areas. To contain their related risks, which will be seemingly amplified by various climate change effects, the engineering community is resorting to so-called “adaptive solutions”, namely, the enhancement of existing defensive structures. In this study, we investigate the efficacy of two different adaptive solutions in reducing the mean overtopping discharge at a vertical seawall. Specifically, this study examines either a wall protected by rubble mound breakwaters or rubble mounds combined with ReefBall modules; while a few studies have recently addressed the former solution, the second one represents a novelty.

To analyze the behavior of these two layouts, we have performed a physical experimental campaign in the small-scale flume of the University of Naples Federico II. Four regular wave conditions have been run to measure the mean overtopping discharge at both an unprotected and a protected vertical wall. In particular, we have tested different rubble mound configurations by varying geometrical features, as well as several arrangements of ReefBall modules on the crown of the breakwater. Laboratory results have indicated that rubble mounds do not exhibit a significant overtopping reducing power, especially for submerged structures. On the other hand, the presence of ReefBalls remarkably lessens the mean flow rate at the wall, especially for certain modules’ dispositions. The present work, hence, explores and highlights the effective capabilities of these adaptive solutions in reducing coastal flooding risks.

Beach erosion is one of the main critical issues affecting coastal areas; its mitigation and prevention are significant challenges for the engineering community. The “headland control” approach indeed represents an interesting solution, since using diffractive structures might induce shoreline responses characterized by a static equilibrium condition (Hsu and Silvester, 1990).

In this work, we have examined the capability of two different one-line models in reproducing such a behavior. In particular, we have compared the well-established one-line model GENESIS (Hanson 1989) with the new one ShorelineS, which has been recently developed by IHE Delft and Deltares (Roelvink et al. 2018). The models differ in various aspects, such as the diffraction modelling and the numerical approach adopted (i.e., ShoreliseS is a flexible vector-based model, while GENESIS exploits a fixed grid). Therefore, the present study aims to assess whether the novelties introduced in ShorelineS make it a more robust and reliable model for predicting shoreline changes behind diffractive structures.

Specifically, we have modelled the static equilibrium profiles behind isolated detached breakwaters and the so-called headland bay beaches and compared numerical outcomes with literature benchmarks. Although GENESIS has provided consistent results, it exhibits some drawbacks that might influence the accuracy of predictions. On the other hand, ShorelineS has proved to be a promising tool able to remarkably predict shoreline equilibrium beaches ruled by diffractive structures.

References

Hanson, Hans (1989). “GENESIS: a generalized shoreline change numerical model”. In: Journal of Coastal research, pp. 1–27.

Hsu, John RC and Richard Silvester (1990). “Accretion behind single offshore breakwater”. In: Journal of waterway, port, coastal, and ocean engineering 116.3, pp. 362–380.

Roelvink, D, B Huisman, and A Elghandour (2018). “Efficient modelling of com plex coastal evolution at monthly to century time scales”. In: Proceedings of the Sixth International Conference on Estuaries and Coasts (ICEC-2018), Caen, France, pp. 20–23.

This article is part of a doctoral thesis to be presented during the Doctoral Program in Marine Sciences of Agostinho Neto University, Supported by the European Union through the UNI.AO program.

The topic is “Analysis of the Main Physical Properties of Seawater Along the Coast of Angola.”

As we know, the ocean has several important properties. However, the primary physical oceanographic properties are water temperature, salinity and density. Studying the variation of these properties allows us to conclude about the general circulation of the oceans. This article aims to analyze the temporal and spatial variation of these properties along the Angolan coast. To achieve the objectives, we used data from the World Ocean Database, which were processed using the software Ocean Data View, and graphical representations of these oceanographic variables. Thus, it was possible to describe the oceanographic phenomena observed.

After analyzing the results, it was possible to identify the stratification and seasonality of seawater along the coast of Angola based on its main oceanographic properties.

Thus, this scientific research is relevant because it provides concrete results on the variation of oceanographic properties such as seawater temperature, salinity, and density along the coast of Angola.

The study is structured as follows: an introduction, which highlights the relevance of the topic and the methodology used; a theoretical framework, where the main concepts related to the subject are defined; a data analysis and discussion section, where the results are examined; and finally, the conclusions.