Coastal Transport Research Articles

Comparison between shear-driven and pressure-driven oscillatory flows over ripples

Direct numerical simulations of oscillatory flow over a bed made of ripples have been performed. Two oscillatory flow forcing mechanisms have been compared: (i) a sinusoidal external pressure gradient (pressure-driven flow); and (ii) a sinusoidal velocity boundary conditions on the rippled bed (shear-driven flow). In the second case, the oscillations of the bed are such that when observed from a reference frame fixed with the bed, the free stream follows the same harmonic oscillation as in the pressure-driven case. While the outer layers have the same dynamics in the two cases, close to the bed differences are observed during the cycle, mostly because the large form drag across the ripples cannot be reproduced in the shear-driven case. A comparison against experimental data from an oscillating tray apparatus provides a relatively good agreement for the phase-averaged flow when the same forcing is considered (i.e. a shear-driven flow). The pressure-driven case has a comparable error to the shear-driven numerical results over the crest of the ripples, whereas the discrepancy is larger at the troughs. The discrepancies between the two cases are more limited for time-averaged flow quantities, such as the mean flow pattern and the time-averaged Reynolds stress distribution. This suggests that numerical or experimental shear-driven configurations may capture well the net effects of coastal transport processes (which occur in pressure-driven oscillatory flow), but care should be exercised in interpreting phase-dependent dynamics near the troughs. More work is needed to fully assess the sensitivity to the forcing mechanisms in different flow regimes.

Constraints of multi-source input and coastal transport on the composition of marine clay minerals: A case study of the northwestern shelf of the South China Sea

Constraints of multi-source input and coastal transport on the composition of marine clay minerals: A case study of the northwestern shelf of the South China Sea

A Comprehensive Study on Winter PM2.5 Variation in the Yangtze River Delta: Unveiling Causes and Pollution Transport Pathways

To thoroughly investigate the impact of meteorological conditions and emission changes on winter PM2.5 variation in the Yangtze River Delta (YRD) from 2015 to 2019, we leveraged advanced modeling techniques, namely, the Weather Research and Forecasting (WRF) model and the Nested Air Quality Prediction Model System (NAQPMS). The results revealed that a notable trend of high-PM2.5-concentration regions shifted from coastal areas towards to the inland regions. While emission reduction can effectively reduce the concentration of PM2.5, meteorological changes exert a significant impact on PM2.5 concentration. Unfavorable meteorological changes in 2018 and 2019 emerged as crucial factors driving PM2.5 pollution in the region (up 0~50 µg·m−3). Our findings also shed light on the potential sources and transport pathways of PM2.5 pollution in key cities within the YRD, indicating that the coastal channel of Hebei–Shandong–Jiangsu and the inland channel bordering Hebei, Henan, Shandong, and Anhui serve as major contributors. Light and moderate pollution was predominantly influenced by the medium-distance coastal channel (48~70%). Remarkably, short-distance inland (19~54%) and coastal transportation (33~53%) channels emerged as the primary causes of severe PM2.5 pollution in the YRD. To effectively combat this issue, it is imperative to bolster key control and prevention measures in these regions.

Microwave detection towards marine climate monitoring: fog and humidity

Sea fog severely impacts marine operations and coastal transportation due to the low visibility, metal corrosion, and unpredictable effects. This paper introduces a microwave detection technique for monitoring the sea fog generation in-time, as well as the salt-content within sea fog. Besides, in the fogless time, the microwave sensor can also work for humidity detection. The proposed sensor doesn’t use the sensitive materials which assure the reliability and stability. In humidity detection, the nested split-ring resonator (NSRR) sensor achieves a maximum sensitivity with a 1.19 MHz/% RH frequency shift, 0.034 dB/% RH return-loss change, and 0.24°/% RH phase change. For NaCl content, the 2NSRR sensor exhibits a significantly higher sensitivity of 4.42 MHz/% compared to the 1NSRR sensor. This paper firstly introduces four non-resonant detection parameters (FWHM, HPI, FSI, and IF) to avoid high loss due to the fog. This microwave sensor and non-resonant parameters offer a comprehensive solution for accurate and timely sea fog monitoring, enhancing safety and efficiency in maritime and coastal operations.

Improving the estimation of direct release rates and transport processes from the Fukushima Daiichi Nuclear Power Plant accident using higher-resolution oceanic dispersion model

A series of accidents at the Fukushima Daiichi Nuclear Power Station (F1NPS), following the 11 March 2011 earthquake and tsunami, resulted in the release of radioactive substances into the ocean. In particular, the release of large amounts of radioactive caesium has damaged the fishing industry, leading to voluntary restrictions on fishing and shipping. Oceanic dispersion simulations based on estimates of the pathways and fluxes of radioactive materials provide useful information for assessing the environmental impacts and formulating measures to mitigate the effects of the accident. For the direct release rate from the F1NPS site, an estimation method was developed using the results from nearby monitoring, and the seawater exchange rate was estimated in target volume using a numerical simulation. However, the influence of volume on the seawater exchange rate was not considered. Appropriate volumes must be considered when estimating the effects of future accidents. In addition, the directional coastal transport was underestimated in the simulations of the F1NPS accident because of the low resolution. To estimate the pathways and fluxes of radioactive material to the ocean and understand the distribution of the concentration of radioactive material based on ocean dispersion simulations, a study was conducted using a higher-resolution model. The horizontal resolution of the conventional ocean dispersion model Regional Ocean Modelling System (ROMS), was increased from 1 km to 200 m. The optimal settings of the seawater exchange rate were investigated, and the radioactive caesium transport process in the coastal direction was more accurately reflected. We found that the conventional volume for determining the seawater exchange rate, including the locations of release sources and observation points, is optimal. The validity of this finding was confirmed using experimental equations from previous oceanic tracer release experiments. To estimate future release rates, it an appropriate volume must be defined, for example, depending on the distance between the locations of the release sources and the observation point. In addition, improvements in the accuracy of the simulation of the coastal transport process were observed owing to the higher resolution, which increased reproducibility. However, with a horizontal resolution of 200 m, problems with repeatability near the harbours arose. A higher resolution, achieved using nesting or other methods, would be desirable to deal with releases smaller than those in the F1NPS accident.

Coastal bridges with a box-girder superstructure under the action of solitary waves: Study on the optimization of bearings, dynamic characteristics and failure mechanism

Coastal bridges featuring a box-girder design are instrumental in advancing coastal transport and economic development. However, numerous coastal bridges with limited clearance above sea level are prone to the impact of the extreme waves. In order to enhance the survivability of superstructures of the bridge in the face of severe wave conditions, the present study implemented measures such as adding steel fasteners to conventional laminated rubber bearings and incorporating fluid viscous dampers to the box-girder superstructure. A three-dimensional fluid-structure coupling model, including a three-dimensional numerical flume, adjacent structures, and a box-girder superstructure supported by various bearings, is developed to explore the failure mechanisms and dynamic properties of the superstructure when subjected to extreme solitary wave conditions. Then, the effects of the implemented measures on the disaster resistance of bridge superstructures are comprehensively examined. The results indicate that: (1) After subjected to extreme solitary wave actions, the box-girder superstructure is at a high risk of failure due to sliding, unseating, and overturning. (2) Adding steel fasteners to conventional laminated rubber bearings can effectively alleviate overturning failure of the box-girder superstructure. (3) The addition of fluid viscous dampers into the box-girder superstructure can effectively decrease its maximum displacement. (4) Bridges with box-girder superstructures typically undergo bearing vertical and deformation failure during their failure process.

Системный анализ экологических факторов при проектировании прибрежных транспортных объектов в арктических морях

Рост промышленной деятельности на акваториях российского нефтегазового арктического шельфа сопровождается созданием различных специализированных многофункциональных грузоперевалочных комплексов, основу которых на трассе Северного морского пути представляют морские порты. Развитие портовой и прибрежной инфраструктуры неразрывно связано с необходимостью обеспечения бесперебойного и безаварийного функционирования порта, а в суровых условиях российской Арктики одним их важнейших вопросов является вопрос обозначения навигационных и экологических рисков в процессе эксплуатации планируемого объекта. В работе проведен детальный анализ непосредственно устьевой акватории реки Индига, выбранной в качестве наиболее подходящего места для возведения нового транспортного объекта. Обозначено значение специфических параметров окружающей природной среды при проектировании прибрежных морских объектов в зоне арктических морей. Представлена оценка влияния прибрежных волновых потоков как наносодвижущего фактора, и основания рассматривать их динамические процессы в комплексе с морфологическими особенностями исследуемой акватории как потенциальную угрозу блокировки будущей судоходной трассы песчаными перемычками. Обоснованы предложения по установке инженерных конструкций волногасящего типа для перекрытия потока наносов и защиты причальных линий от прямого волнового воздействия. The growth of industrial activity in the waters of the Russian Arctic oil and gas shelf accompanied by the creation of various specialized multifunctional cargo complexes. Seaports represent the basis of cargo complexes on the route of the Northern Sea Route. The development of port and coastal infrastructure closely linked to ensuring trouble-free operation of the port. In the harsh conditions of the Russian Arctic, one of their most important issues is the designation of navigational and environmental risks of the new facility. The paper provides a detailed analysis of the mouth of the Indiga River. This water area has been chosen as the most suitable place for the construction of a new transport facility. The importance of specific environmental parameters in the design of coastal marine facilities in the Arctic seas zone indicated. The paper presents an assessment of the influence of coastal wave flows as a factor creating the shoal. The reasons are present to consider the dynamic processes and morphological features of the studied water area as a potential threat of blocking the future shipping route by sand bridges. The proposals for the installation of engineering wave-damping structures are substantiated. Their purpose is to block the flow of sediment and protect the marine berths from direct wave action.

Assessing vulnerability and enhancing resilience of port systems in southeast Texas facing sea-level rise

Climate change and the associated sea level rise (SLR) are presenting newfound challenges to the port systems and coastal transportation infrastructure of southeast Texas. This paper introduces a Geographic Information Systems (GIS) based model designed to simulate inundation scenarios under various sea-level projections, aiming to assess the vulnerabilities of both port facilities and road networks. The study area encompasses a specific region within Jefferson County, southeast Texas, encompassing three major ports: Port Arthur, Beaumont, and Orange. Utilizing a high-resolution (1-m) Digital Elevation Model (DEM) derived from the 2017 LiDAR dataset, this model is integrated with NASA’s sea-level rise projections to compute the extent and volume of inundation across low, medium, and high SLR scenarios. Drawing from monthly mean sea level data spanning from 1958 to 2020, the lowest SLR projections, derived from the relative sea-level trend measured at the Sabine Pass, TX gauge station, indicate a yearly increase of 6.16 mm, with a 95% confidence interval of +/- 0.74 mm. Projections for 2050 and 2,100 show the lowest SLR at 0.17 m and 0.48 m, respectively. In contrast, the medium to high RSLR projections under the IPCC SSP3-7.0 scenario for 2050 and 2,100 stand at 0.54 m and 1.34 m, respectively. The findings reveal that, under medium to high SLR scenarios, the extent of inundated areas in the study region is expected to expand by 12.4% in 2050 and 19.9% in 2,100, compared to the lowest SLR projection. Additionally, the length of submerged roadways is predicted to increase by 6.9% in 2050 and 13.3% in 2,100, in comparison to the lowest SLR projection. It is worth noting that some margin of error may be introduced due to factors such as the width of the port area and access roads, the high-resolution DEM, and the alignment of computed inundated areas with the existing topography. Overall, the manuscript highlights the urgency of proactive planning and underscores the importance of safeguarding critical infrastructure in the context of climate change and SLR.

A Case Study of Maritime Hydrogen Energy Development in Jiangsu Province in China

This study aims to develop a systematic review of hydrogen energy storage technologies and maritime applications, intending to present an international perspective on the matter. This study analyses the role of advanced storage methods in enabling renewable energy systems integration in coastal regions, using Jiangsu Province of China as an example. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was used as the research method. Data was obtained from research studies over the period 2015–2023. The analysis included a total of 96 papers from Web of Science, Scopus, IEEE Xplore, and ScienceDirect databases. Results show that Europe and East Asia led publications at the intersection of hydrogen storage and marine applications over the past decade. One of the main issues associated with maritime hydrogen adoption found in the dissertation is related to the mismatch between technological readiness levels and commercial maturity. Findings indicate promise for fuel cell integration with ships, ports, offshore wind farms, and other coastal transport sectors. However, the realization of the project depends on infrastructure development, policy support, and viable business models tailored to the marine environment. Focused demonstration projects and public-private collaboration can further progress towards robust hydrogen-based energy storage ecosystems in suitable regions like Jiangsu and beyond.

Modeling climate change effects on transport and fate of pathogens in an urban coastal area of Lake Michigan

Abstract Infrastructure renewal and public health efforts require prediction of climate change effects on the occurrence of pathogens in the Great Lakes' urban coastal waters. This paper presents an investigation that addressed the climate change effects on transport and the fate of bacteria in Milwaukee's urban coastal area. This investigation was part of a study on climate change risks and impacts that included downscaling of climate change data for meteorological stations around Lake Michigan, and implementation of a hydrologic model that predicts tributary flows and bacteria loads. A method to select scenarios appropriate to link watershed and lake transport processes is presented. For the watershed, the sensitivity of bacterial loads with respect to changes in spring-season precipitation and air temperature is critical, while for lake transport, the most important driver is the wind field. Watershed and lake processes are linked by using spring-season watershed loading in the simulation of coastal transport. Scenarios for hydrodynamic modeling were developed by selecting climate projections that yielded high-and-low percentile projected spring-season wind speed. The patterns of bacteria transport showed significant changes under climate change conditions, and the changes in fecal coliform concentration at critical locations were explained by changes in current vector fields.

Probabilistic risk assessment of hurricane-induced debris impacts on coastal transportation infrastructure

Probabilistic risk assessment of hurricane-induced debris impacts on coastal transportation infrastructure

Study on the mechanical characteristics and failure mechanism of the coastal bridge with a box-girder superstructure under the action of breaking solitary waves

Nowadays, bridges with a box-girder superstructure play a crucial role in coastal transportation systems, and many low-lying coastal bridges are severely threatened by breaking waves. However, the study on dynamic characteristics of coastal bridges with a box-girder superstructure under the action of breaking solitary waves is limited, which is crucial for the rational design of these bridges. In this study, a two-dimensional numerical model, including a numerical wave flume and a box-girder superstructure model with a simplified connection system, is developed. The breaking mechanism of solitary waves and the influence of different forms of breaking solitary waves on the box-girder superstructure are investigated in detail in this study. Furthermore, three common failure modes, including the deformation of bearings, sliding between the box-girder superstructure and bearings, and unseating of the box-girder superstructure, and the influence of the damping ratio of bearings on the box-girder superstructure are studied in detail. The results indicate that: (1) The box-girder superstructure is most vulnerable to solitary waves in the breaking state. (2) The unseating and sliding failures of box-girder superstructure under the action of breaking solitary waves are typically accompanied by the deformation and vertical failure of bearings. (3) Increasing the damping ratio of bearings can effectively reduce the lateral displacement and vibration of the box-girder superstructure.

A first approach of beach sanding on the Black Sea Romanian’s coast

The Romanian coastline, which is subject to complex processes of geomorphological evolution due to beach sanding actions, as well as other natural and anthropogenic factors. Beach sanding is an important action in the maintenance and development of coastal areas, it provides protection against erosion, contributes to the formation and maintenance of beaches, as well as to the preservation of coastal ecosystems The main source of sand for Romanian beaches is coastal transport, i.e. the movement of sand along the coast under the action of values, current and wind. Naturally, there is some redistribution of sand along the coast, with an area where it accumulates and an area where it is lost. However, human intervention and other influences can disrupt this natural balance. In order to counteract the negative impact of insufficient sanding, various coastal management measures have been implemented in Romania. These include the artificial replenishment of beaches by bringing in additional sand from the seabed or other sources, as well as the construction of beach protection and stabilization works.

Influences of Tides, Winds, and Bathymetry on Surface Transport Through a Complex Nearshore System: Measurements from GPS Drifters and an Uncrewed Aerial Vehicle

Bathymetric features such as dredged channels, constricted-inlet basins, and nearshore islands have known influences on coastal transport, which are typically studied on an individual basis. However, their interactive effects on flow when found in the same area are poorly characterized. A multi-season study was conducted to characterize surface transport in and around Wood Island Harbor, in the southwestern Gulf of Maine, where these features all exist in close proximity. Patterns of surface transport were assessed with repeated series of Uncrewed Aerial Vehicle flights and deployments of GPS drifters across tidal conditions and winds typical to the area. Transport followed a major axis through the harbor, as a result of the combined effects of the linked inlet-channel system. Despite the complex topography, the individual dynamics of transport are maintained. Tidal variations explained a majority of displacement (R2 = 0.752) along the channel axis, while across-channel wind velocity explained the majority of orthogonal displacement (R2 = 0.646). Flow in the area was friction-dominated, and both inter-island passages and the deep channel served to direct flow. The offshore transport of tidally driven flows from a constricted-inlet basin was enhanced by deep channels, with flow primarily following bathymetric contours. Our observations suggest that surrounding topography lessened the role of wave energy in governing transport. The co-occurrence of bathymetric features around a constricted-inlet basin can disrupt the typical influences of physical mechanisms on surface transport, leading to a greater importance of local conditions and the larger-scale circulation of the area.

Quantification of coastal transportation network resilience to compounding threats from flooding and anthropogenic disturbances: A New York City case study

Technological advancements and management adaptations have improved the function of engineered systems in response to threats from coastal flooding. Other natural and anthropogenic disturbances such as pandemics, utility hijacking, infrastructure destruction, and biochemical releases can stress a system beyond acceptable limits or in ways not previously conceived. Such threats can be direct or indirect and often result in large-scale disruption to the critical functions of the system. Traditional risk management approaches, while effective for known and predictable threats, are not adequate preparation for compound disturbances that are often unpredictable and not well defined. Rather, a resilience-based approach is required. Resilience-based approaches acknowledge that multiple disruptions to the system will occur, such as the interaction of impending hurricanes and evacuation complications due to a pandemic, while focusing on the recovery and maintenance of critical functions. The system can be stressed with multiple disturbances to determine its capacity to resist and recover. Analysis of these capacities or subsequent failures can then be used to determine the resilience of the system and provide insight into remedial actions or improvements. A framework combining hydrologic modeling and network science can be used to determine critical weaknesses in transportation infrastructure due to compounding threats. This determination could be used to address pre-disaster staging by identifying areas that are likely to be isolated and to identify the characteristics of a resilient network to incorporate into future designs. To analyze resilience under compounded disturbances, coastal flood modeling is combined with hypothetical vehicle bridge failure in New York City, USA, and connectivity is analyzed through the use of ego networks. Our results show network analysis can be effectively used to identify areas of need to improve whole network resilience and is a valuable tool to quantify the compounding effects of multiple threats.

Electrification of Excavators: Electrical configurations, carbon footprint, and cost assessment of retrofit solutions

Technology for the electrification of transport is currently undergoing rapid development that is necessary for reducing greenhouse gas (GHG) emissions. On a global level, the transport sector is responsible for around 12% of the world’s GHG emissions. While the introduction of battery-electric cars is leading the way in terms of commercial scale, developments are also progressing toward electrification of heavy-duty vehicles for road freight transport and coastal transport by battery-electric ships. The performance of modern Li-ion batteries is also enabling electrification of other types of machines and small vehicles that have traditionally been powered by internal combustion engines (ICEs). However, until recently, the developments toward electrification have been mainly directed toward applications with either a large market for series-produced vehicles, such as electric cars, or a high degree of individual engineering for each unit, such as battery-electric ships. Still, there are several application areas where other types of vehicles and machines contribute significantly to GHG emissions.

Перспективы создания общего рынка транспортных услуг ЕАЭС

The Eurasian Economic Union, in its development and formation, sets itself many goals and objectives: the formation of a common market for goods, capital, labor, including the creation of a common market for transport services. The purpose of the study is to analyze cargo and passenger turnover, to consider the prospects for creating a common market for transport services in the context of integration processes taking place in the Eurasian Economic Union. The study was conducted on the basis of statistical data of the Eurasian Economic Commission using general scientific research methods. The article considers the main provisions and objectives of a coordinated policy in the field of creating a single transport space; analyzes the statistics presented on this issue; describes the main stages of the implementation of the Coastal Transportation Program, the implementation of which is scheduled until 2025. The novelty of the work consists in analyzing problematic issues when creating a single transport space of the Union, highlighting the main priorities for achieving this goal.

Small-scale shipping and the maritime commerce of eighteenth-century St. Petersburg

The paper discusses the history of eighteenth-century St. Petersburg coastal shipping in the context of the Early Modern European coastal transportation growth. Based on the sources significantly understudied so far, I discuss the spatial and economic aspects of St. Petersburg coastal transportation. Using the conceptual framework of the littoral society and Greater St. Petersburg, I discuss the uncertainty of the very concept of the St. Petersburg coastal fleet. Based on the detailed account of the St. Petersburg coastal fleet prepared in the late eighteenth century, I reveal the commercial strategies used by the St. Petersburg merchants in their competition with their European counterparts. These observations confirm that St. Petersburg became a focal point of an enormous network of water transportation, and the local merchants used the coastal fleet as an efficient instrument of participation in international maritime commerce.

Evaluation of the effective factors of unloading and loading goods in ports and the impact on the environment using the MCDM method.

Today, the impact of transportation on sustainable development is undeniable. Maritime transport, as one of the important pillars of this industry and due to its advantages such as low cost and large volume of freight, plays a key role in the development of foreign trade. This study uses TOPSIS and DEMATLE methods to evaluate the factors affecting the unloading and loading of goods on the port's environment. The results of TOPSIS method on the main criteria showed that the atmospheric factors' criterion had the highest weight and the port criterion (includes activities that occur in the port) had the lowest weight. In the sub-criteria section, the suitable visibility of the crane operator had the highest rank and the sub-criterion of storage capacity and its (storage) area obtained the lowest rank. Also, the results of DEMATEL method on the cause-and-effect relationship of sub-criteria of unloading and loading of goods showed that coastal transport equipment, unloading and loading equipment, and safety required for unloading goods are influenced higher than other sub-criteria and also the impact of safety required for unloading goods, proper visibility of the crane operator, and the ability of unloading equipment is greater than other sub-criteria. The results of cause-and-effect relationship for sub-criteria of the port environment showed that the impact of sewage, sanitary effluents from the port and ships, and hazardous waste is higher than other sub-criteria and also the impact of petroleum hydrocarbons, sediments, and toxic substances is higher than other sub-criteria.

Erosion and siltation dynamics in an urban-influenced coastal setting, Xiamen Island, China

The evolution of seafloor erosion-siltation in urban bays has received wide attention owing to its high susceptibility to natural factors and human activity, Xiamen is a typical coastal city in China that has undergone rapid urban development. Here, we studied seafloor erosion-siltation in the sea to the east of Xiamen Island. In particular, we focused on the responses of erosion-siltation to changes in the natural environmental factors and intensive human activity. The spatial distribution and transport trends of surficial sediments, changes in sedimentary records, and erosion-siltation dynamics were analyzed based on surficial sediments, core sediment within a time span of ca.100 years, and new and historical bathymetric data. The results showed that surficial sediments were mainly transported to the northwest and southwest, three stage changes in sedimentary records have occurred, the shoreline gradually moved seaward and became straighter, and the erosion-siltation state shifted from slight erosion to siltation. Before the 1930s, climate change with alternating aridity and humidity controlled the influence area of the Jiulong River sediment input. During the subsequent period (1930s to the early 1970s) of enhanced human activity in the drainage basin, the increased river sediment input only promoted siltation in some of the study areas; however, after the 1970s, river sediment input was no longer a dominant factor in the evolution of erosion-siltation. During the rapid urban development in Xiamen, coastal development and construction on Xiamen Island resulted in a large influx of sediment into the sea directly. This compensated for the decreased river sediment input and shifted the study area toward siltation. Meanwhile, rapid siltation was triggered in some of sediment convergence areas and the Jinmen Channel, where the dredging and maintenance demands were low. While channel dredging and maintenance coupled with sediment back siltation caused significant short-term topography changes in the Xiamen East Channel. Land reclamation directly shrank tidal flats along Xiamen Island. Moreover, normal wind-generated waves and occasional intensification typhoon events affected the long-term evolution of these tidal flats via persistent erosion coupled with coastal transport, and drastic short-term erosion, respectively.