Search Results (210)

Prolonged inundations are altering coastal forest ecosystems of the southeastern US, causing extensive tree die-offs and the development of ghost forests. This hydrological stressor also alters carbon fluxes, threatening the stability of coastal carbon sinks. This study was conducted to investigate the interactions between hydrological drivers and ecosystem responses by analyzing daily eddy covariance flux data from a wetland forest in North Carolina, USA, spanning 2009–2019. We analyzed temporal patterns of net ecosystem exchange (NEE), gross primary productivity (GPP), and ecosystem respiration (RE) under both flooded and non-flooded conditions and evaluated their relationships with observed tree mortality. Generalized Additive Modeling (GAM) revealed that groundwater table depth (GWT), leaf area index (LAI), NEE, and net radiation (Rn) were key predictors of mortality transitions (R² = 0.98). Elevated GWT induces root anoxia; declining LAI reduces productivity; elevated NEE signals physiological breakdown; and higher Rn may amplify evapotranspiration stress. Receiver Operating Characteristic (ROC) analysis revealed critical early warning thresholds for tree mortality: GWT = 2.23 cm, LAI = 2.99, NEE = 1.27 g C m⁻² d⁻¹, and Rn = 167.54 W m⁻². These values offer a basis for forecasting forest mortality risk and guiding early warning systems. Our findings highlight the dominant role of hydrological variability in ecosystem degradation and offer a threshold-based framework for early detection of mortality risks. This approach provides insights into managing coastal forest resilience amid accelerating sea level rise. Full article

Hydrogen is a potential key component of a carbon-neutral energy carrier and an input to marine industrial processes. This study examines the consequences of coupled hydrogen release and marine environmental factors during floating photovoltaic hydrogen production (FPHP) system failures. A validated three-dimensional numerical model of FPHP comprehensively characterizes hydrogen leakage dynamics under varied rupture diameters (25, 50, 100 mm), transient release duration, dispersion patterns, and wind intensity effects (0–20 m/s sea-level velocities) on hydrogen–air vapor clouds. FLACS-generated data establish the concentration–dispersion distance relationship, with numerical validation confirming predictive accuracy for hydrogen storage tank failures. The results indicate that the wind velocity and rupture size significantly influence the explosion risk; 100 mm ruptures elevate the explosion risk, producing vapor clouds that are 40–65% larger than 25 mm and 50 mm cases. Meanwhile, increased wind velocities (>10 m/s) accelerate hydrogen dilution, reducing the high-concentration cloud volume by 70–84%. Hydrogen jet orientation governs the spatial overpressure distribution in unconfined spaces, leading to considerable shockwave consequence variability. Photovoltaic modules and inverters of FPHP demonstrate maximum vulnerability to overpressure effects; these key findings can be used in the design of offshore platform safety. This study reveals fundamental accident characteristics for FPHP reliability assessment and provides critical insights for safety reinforcement strategies in maritime hydrogen applications. Full article

This study addresses the dynamic response control of deep-water jacket offshore platforms under typhoon and misaligned wave loads by proposing a Tuned Mass Damper (TMD)-based vibration suppression strategy. Typhoon loading is predicted using the Weather Research and Forecasting (WRF) model to simulate maximum wind speed and direction, a customized exponential wind profile fitted to WRF results, and a spectral model calibrated with field-measured data. Correspondingly, typhoon wave loading is calculated using stochastic wave theory with the Joint North Sea Wave Project (JONSWAP) spectrum. A rigorous Finite Element Model (FEM) incorporating soil–structure interaction (SSI) and water-pile interaction is implemented in the Opensees platform. The SSI is modeled using nonlinear Beam on Nonlinear Winkler Foundation (BNWF) elements (PySimple1, TzSimple1, QzSimple1). Numerical simulations demonstrate that the TMD effectively mitigates dynamic platform responses under aligned typhoon and wave conditions. Specifically, the maximum deck acceleration in the X-direction is reduced by 26.19% and 31.58% under these aligned loads, with a 17.7% peak attenuation in base shear. For misaligned conditions, the TMD exhibits pronounced control over displacements in both X- and Y-directions, achieving reductions of up to 29.4%. Sensitivity studies indicated that the TMD’s effectiveness is more significantly impacted by stiffness detuning than mass detuning. It should be emphasized that the effectiveness verification of linear TMD is limited to the load levels within the design limits; for the load conditions that trigger extreme structural nonlinearity, its performance remains to be studied. This research provides theoretical and practical references for multi-directional coupled vibration control of deep-water jacket platforms in extreme marine environments. Full article

Coastal and maritime regions and their entities face accelerated degradation due to the combined effects of environmental stressors and anthropogenic activities. Coastal degradation can be identified, visualized and estimated through periodic monitoring over a region of interest using earth observation, climate, meteorological, seasonal, waves, sea level rising, and other ocean- and maritime-related datasets. Usually, these datasets are provided through different sources, in different structures or data types; in many cases, a complete dataset can be large in size and needs some kind of preprocessing (information filtering) before use in the intended application. Recently, the term data cube introduced in the scientific community and frameworks like Google Earth Engine and Open Data Cubes have emerged as a solution to earth observation data harmonization, federation, and exchange framework; however, these sources either completely lack the ability to process climate, meteorological, waves, sea lever rising, etc., data from open sources, like CORDEX and WCRP, or preprocessing is required. This study describes and utilizes the Ocean-DC framework for modular earth observation and other data types to resolve major big data challenges. Compared to the already existing approaches, the Ocean-DC framework harmonizes several types of data and generates ready-to-use data cubes products, which can be merged together to produce high-dimensionality visualization products. To prove the efficiency of the Ocean-DC framework, a case study at Crete Island, emphasizing the Port of Heraklion, demonstrates the practical utility by revealing degradation trends via time-series analysis of several related remote sensing indices calculated using the Ocean-DC framework. The results show a significant reduction in processing time (up to 89%) compared to traditional remote sensing approaches and optimized data storage management, proving its value as a scalable solution for environmental resilience, highlighting its potential use in early warning systems and decision support systems for sustainable coastal infrastructure management. Full article

The new generation of food packaging should not only be biodegradable, but also provide additional protective properties for packaged products, extending their shelf life. In this paper, we present the results of research on cast-extruded poly(butylene succinate) (PBS) films coated with hydroxypropyl methylcellulose (HPMC) modified with CO₂ extract from sea buckthorn (ES) or its ethosomes (ET) at amounts of 1 or 5 pph per HPMC. In addition, the developed films were exposed to accelerated aging (UV radiation and elevated temperature) to determine its effect on the films’ properties. Based on SEM, it can be concluded that accelerated aging results in the uncovering of the extract and ethosomes from the coating’s bulk. GPC showed a decrease in the molecular weight of PBS after treatment, additionally amplified by the presence of HPMC. However, the addition of ES or ET in low concentrations reduced the level of polyester degradation. The presence of the modified coating and its treatment increased the oxygen barrier (a decrease from 324 cm³/m² × 24 h for neat PBS to 208 cm³/m² × 24 h for the coated and modified PBS ET5). Despite the presence of colored extract or ethosomes in the coating, the color differences compared with neat PBS were imperceptible (ΔE < 1). The addition of 5 pph of sea buckthorn extract or its ethosomes in combination with accelerated aging resulted in the complete inhibition of the growth of E. coli and S. aureus, which was not observed in non-aged samples. The results obtained demonstrate an improvement in bioactive properties and protection against the negative effects of UV radiation on the film due to the presence of ET or ES in the coating. The developed systems could be used in the food industry as active packaging. Full article

Ubiquitous and accelerating mass loss from the Greenland Ice Sheet (GrIS) has been widely reported in recent scientific studies, implying rapid changes in the Arctic cryosphere. However, while numerous studies provide accounts of glacial mass loss and consequent sea level change, a qualitative assessment of the implications is conspicuously absent. This scoping review addresses that gap by synthesizing the recent scientific literature related to cryospheric change in Greenland and its implications for key species and ecological processes; and highlights the necessity of understanding the bigger picture of how multiple ecological processes, abiotic-biotic assemblages, and cryosphere-human interactions with the environment are rapidly changing and pushing the Arctic into a possible no-analog scenario in recent geological times. It is also argued that this situation presents a novel challenge for planetary sustainability and warrants the identification of new research priorities that can generate a holistic understanding of the complexity of the Arctic cryosphere, interactions between biotic and abiotic components, and local lifeworlds—all of which are related to the well-being of the Earth itself. Full article

California and most other coastlines around the nation and the world are being impacted by both long-term sea-level rise (SLR) and short-term extreme events. Global sea level over the last 10 years of satellite altimetry has averaged approximately 4.1 mm/yr. (~16 in./100 yrs.), although this rate is accelerating at about 1.2 mm/yr. per decade. Projections of future sea levels have now been developed by many different agencies, organizations, and committees, and cluster around 12 inches by 2050. Over the near term, however, until mid-century, and likely beyond, it will be the short-term extreme events such as hurricanes along the U.S. Atlantic and Gulf coasts, and the coincidence of very large waves and high astronomic tides along the U.S. Pacific coasts that will pose the major threat to both public infrastructure and private development. Full article

The development of marine new quality productive forces and the enhancement of marine economic resilience are critical strategies for cultivating new drivers and advantages for high-quality and sustainable development in the marine sector. In order to deeply explore the relationship between these two constructs, this study selected panel data from 11 coastal provinces from 2007 to 2021 to construct an indicator system for MNQPFs and marine economic resilience, conducted scientific calculations and analysis, and, finally, used a two-way fixed effect model for empirical analysis and the instrumental variable method for robustness testing. The key findings are as follows: (1) The level of marine new quality productive forces (MNQPFs) in coastal areas demonstrates considerable spatial variability. The spatial distribution of MNQPF levels in the Bohai Sea and South China Sea regions is similar, whereas the levels in the Yellow Sea and East China Sea region demonstrate better balance. (2) A regional analysis of marine economic resilience indicates that the Bohai Sea region demonstrates a weak development trend and the South China Sea region demonstrates an unbalanced development trend, while the Yellow Sea and East China Sea region demonstrates a favorable development trend. (3) MNQPFs significantly improve marine economic resilience, including both its resistance and evolution abilities; the positive impact of marine new quality productive forces on the marine economic resilience’s recovery ability exhibits a time lag effect. (4) Heterogeneous results demonstrate that the positive impact of MNQPFs on marine economic resilience varies according to the level of marine economic development in different coastal areas, with a more significant promoting effect in less developed areas. Therefore, adaptively accelerating the development of marine new quality productive forces according to local conditions by effectively utilizing the unique resource endowments of each coastal area is essential for continuously strengthening marine economic resilience. This study can enrich research in the field of marine economics and provide references for marine economic development in coastal areas. Full article

Existing radar target-detection methods exhibit suboptimal performance when they are applied to sea-surface target detection. This is due to the difficulties in detecting weak targets and the interference from sea clutter, as well as to the inability of statistical models to accurately model sea-surface targets, which leads to degraded detection performance. With the development of artificial intelligence technologies, research based on deep learning methods has gained momentum in the field of radar target detection. Considering the complexity of neural networks and the real-time requirements of radar target-detection algorithms, this paper investigates a sea-surface radar target-detection method based on an improved U-Net network and its FPGA implementation, achieving real-time radar target detection without relying on GPUs. This paper first selected the lightweight U-Net network through a survey and analysis. The original U-Net network was then structurally optimized using network volume-reduction methods. Based on the characteristics of the network structure, optimization strategies such as pipelining and parallel processing, hybrid-layer design, and convolution-layer optimization were applied to the accelerator system. These optimizations reduced the system’s hardware-resource requirements and enabled the complete deployment of the network onto the accelerator system. The accelerator system was implemented using high-level synthesis (HLS) with modular and template-based design approaches. Experiments showed that the proposed method has significant advantages in improving detection probability, reducing false-alarm rates, and achieving real-time processing. Full article

Existing research concentrates on analyzing the propagation and recovery of complex network risk or failure under a single model, which makes it difficult to effectively deal with the chain reaction. Concerning the recovery delay caused by the risk–failure interactions, this paper proposes a model for the propagation and recovery of risk–failure interactions. This model not only considers the network risk–failure interactive propagation mechanism but also introduces the load-balancing strategy and repair mechanism. The study quantifies the impact of the station on network resilience after different attack modes. In addition, the resilience metrics based on the station failure are established to accurately represent the resilience evolution of the network during propagation and recovery. Finally, focusing on the Belt and Road transportation network, we explore the evolution of network resilience under the variation of failure station repair time, station risk state recovery rate, and hub station allocation parameters. The simulation results showed that the model reduced the resilience loss through resilience recovery and accelerated the network back to normal in the face of attacks, shortening the station repair time and increasing the station risk recovery rate significantly improved the overall resilience level of the network, and increasing the proportion of hub station balancing based on the residual capacity effectively improved the minimum resilience of the sea–rail intermodal transportation network. Full article

Mangroves are coastal ecosystems of great ecological importance, located in transition areas between marine and terrestrial environments, predominantly found in tropical and subtropical regions. In Brazil, these biomes are present along the entire coastline, playing essential environmental roles such as sediment stabilization, coastal erosion control, and the filtration of nutrients and pollutants. The unique structure of the roots of some mangrove tree species facilitates sediment deposition and organic matter retention, creating favorable conditions for the development of rich and specialized biodiversity, including fungi, bacteria, and other life forms. Furthermore, mangroves serve as important nurseries for many species of fish, crustaceans, and birds, being fundamental to maintaining trophic networks and the local economy, which relies on fishing resources. However, these ecosystems have been significantly impacted by anthropogenic pressures and global climate change. In recent years, the increase in average global temperatures, rising sea levels, changes in precipitation patterns, and ocean acidification have contributed to the degradation of mangroves. Additionally, human activities such as domestic sewage discharge, pollution from organic and inorganic compounds, and alterations in hydrological regimes have accelerated this degradation process. These factors directly affect the biodiversity present in mangrove sediments, including the fungal community, which plays a crucial role in the decomposition of organic matter and nutrient cycling. Fungi, which include various taxonomic groups such as Ascomycota, Basidiomycota, and Zygomycota, are sensitive to changes in environmental conditions, making the study of their diversity and distribution relevant for understanding the impacts of climate change and pollution. In particular, fungal bioremediation has gained significant attention as an effective strategy for mitigating pollution in these sensitive ecosystems. Fungi possess unique abilities to degrade or detoxify environmental pollutants, including heavy metals and organic contaminants, through processes such as biosorption, bioaccumulation, and enzymatic degradation. This bioremediation potential can help restore the ecological balance of mangrove ecosystems and protect their biodiversity from the adverse effects of pollution. Recent studies suggest that changes in temperature, salinity, and the chemical composition of sediments can drastically modify microbial and fungal communities in these environments, influencing the resilience of the ecosystem. The objective of this narrative synthesis is to point out the diversity of fungi present in mangrove sediments, emphasizing how the impacts of climate change and anthropogenic pollution influence the composition and functionality of these communities. By exploring these interactions, including the role of fungal bioremediation in ecosystem restoration, it is expected that this study would provide a solid scientific basis for the conservation of mangroves and the development of strategies to mitigate the environmental impacts on these valuable ecosystems. Full article

Among the diverse challenges to the sustainability of China’s rich tangible cultural heritage, climate change, associated with increased temperatures, altered precipitation regimes, and the augmented frequency and magnitude of extreme events, is regarded as one of the most prominent. However, there is a diverse range of rapidly emerging environmental and socio-economic hazards that threaten cultural heritage in the country but have thus far received scant attention in this context. Without adequate attention and intervention, the sustainability of the country’s historic urban heritage is highly vulnerable. Anthropocene threats to this important legacy include climate change, sea level rise, land subsidence, water and air pollution, rampant urbanization, and tourism. Suzhou, situated in the low-elevation Yangtze River delta within one or two meters of current sea level, lies in the heart of one of the fastest socio-economically developing and urbanizing regions in the world and is especially vulnerable to the range of threats. As one of the jewels in the crown of China’s architectural heritage, Suzhou represents a model case in which to consider the conflicting interests of socio-economic development and environmental and cultural conservation in the context of rapidly changing environmental conditions. In this review, we consider the diverse risks to the sustainability of Suzhou’s cultural heritage posed by these circumstances, highlight key problems, and prioritize the most urgent issues requiring attention. In recognizing the spatial and temporal nature of these multiple challenges, we highlight the need for integrated approaches to safeguard the sustainability of such valuable resources. Moreover, considering the imperative of accelerating progress towards the UN Sustainable Development Goals and reflecting on current theories of sustainable management of urban cultural heritage, we outline the potential policy and practice implications for the conservation of Suzhou’s historic buildings, canals, and gardens. Full article

Here, we discuss the results of an experiment in toe-line protection of estuarine embankments from frequent slope failure using silt traps. We test the feasibility of terracotta rings to trap silt and promote natural mangrove regeneration in barren patches in front of embankments around human settlements in the Indian Sundarban region, designated as the Sundarban Biosphere Reserve. The initial results of the first sixteen months of observations, between May 2023 and August 2024, are encouraging. Sediment accumulation in the silt traps across sites ranges between 4 and 42 cm. Periodic granulometric analyses of sediments indicate that while the middle estuarine sites accumulate more clay/silt, the lower estuarine sites accumulate more sand. During the late and post-monsoon seasons, all sites except one, on the eastern coast of the lower estuarine island, exhibit natural mangrove regeneration, the main species being Porteresia coarctata, Sueda maritima and Avicennia marina. Additionally, oysters Saccostrea cuculata and occasionally Crassostrea cuttakensis are found attached to the terracotta silt traps. The results highlight the potential of the nature-based Living Shoreline strategy to support mangrove regeneration and toe-line protection cost-effectively. The study also successfully opens up new possibilities for sustainable elevation management in the sinking and shrinking mangrove region of the Sundarbans, a significant development in the face of climate change and accelerated sea level rise. Full article

Cape Canaveral, home to critical space exploration infrastructure, is facing potential flooding hazards from land subsidence and sea-level rise. This study utilized three geodetic datasets, the Interferometric Synthetic Aperture Radar (InSAR), the Global Navigation Satellite System (GNSS), and precise leveling, to investigate the spatial and temporal patterns of vertical land motion (VLM) in Cape Canaveral and its surrounding areas. Our analysis revealed that Cape Canaveral experiences both long-term regional subsidence and localized subsiding areas, while Merritt Island and the Peninsular Mainland remain relatively stable. The long-term regional subsidence in Cape Canaveral is likely driven by the compaction of younger, unconsolidated siliciclastic sediments, with a small contribution from glacial isostatic adjustment (GIA). The three localized subsiding areas identified in Cape Canaveral are each driven by distinct mechanisms: wetland modification in the western area, runway infrastructure development in the central area, and the natural compaction of young siliciclastic sediments in the southeastern region. Historical leveling data indicated temporal variations in subsidence rates at Cape Canaveral, from 5 mm/yr during the 1950–70s to 2 mm/yr in the 2000s. These findings have significant implications for infrastructure resilience and flood hazard assessment, as the observed subsidence compounds with the projected accelerated sea-level rise in the region. Our results highlight the importance of integrating long-term datasets to better characterize VLM in the dynamic coastal region for effective planning and risk mitigation. Full article

The response of large temporary working platforms for cross-sea bridges under the action of strong wind and waves with large tidal ranges is one of the key issues in offshore engineering. Based on a grand offshore bridge project in Fujian Province of China, on-site monitoring tests were carried out on a temporary working platform. A high-precision and fully automatic monitoring system was adopted to conduct the all-weather and high-frequency monitoring on vibrations, responses, and sea conditions of the platform, enabling us to grasp its structural mechanical characteristic and ensuring the platform safety. The results show that, under the severe sea conditions of typhoons, the stress of the platform structure increases significantly with the increase in the tidal range and reaches its maximum value at the high tide level. The inclination angle changes violently at the high tide level, while the amplitude of inclination angle change is relatively small at the low tide level. The effective value of the platform displacement under the severe sea conditions of typhoon meteorology is much larger than that under normal sea conditions. Compared with the low tide level, the acceleration of the offshore temporary work platform changes more drastically at the high tide level under severe sea conditions. Under severe sea conditions, the tidal level has a significant impact on the frequency corresponding to the peak value of the acceleration power spectrum of the offshore temporary platform. Full article