Article
Engineering, Civil
Nan Wang, Qin Chen, Kelin Hu, Kehui Xu, Samuel J. Bentley, Jiaze Wang
Summary: This study used a Delft3D model to explore the hydrodynamics and sediment transport in Fourleague Bay, Louisiana. The findings show that by aligning river water pulses with atmospheric conditions, the growth of surrounding wetlands can be promoted and the distance over which they benefit from sediment diversions can be extended. Multiple sediment transport processes were observed under different weather conditions.
COASTAL ENGINEERING
(2023)
Article
Engineering, Civil
Andrew W. Stevens, Hans R. Moritz, Edwin P. L. Elias, Guy R. Gelfenbaum, Peter R. Ruggiero, Stuart G. Pearson, James M. McMillan, George M. Kaminsky
Summary: A submerged, low-relief nearshore berm was constructed in the Pacific Ocean near the mouth of the Columbia River, USA, using sediment dredged from the adjacent navigation channel. Field measurements and numerical modeling were used to evaluate the transport pathways and physical processes responsible for dispersal of the berm. The study found that the berm was effective in enhancing the sediment supply along the eroding coastline.
COASTAL ENGINEERING
(2023)
Article
Geosciences, Multidisciplinary
Taian Lu, Houjie Wang, Limin Hu, Xiao Wu, Naishuang Bi, Yao Dang, Prakhin Assavapanuvat, Thomas S. Bianchi
Summary: The Yellow River has experienced significant environmental changes due to dam regulations, affecting the downstream hydrologic regime and sediment and POC transport. This study investigated the changes in sources and transport of POC from the lower Yellow River to the river mouth under different dam operation stages. The results showed that riverbed erosion and clear water release from the reservoir contributed to enriched delta 13C POC, while muddy floodwaters and sediment released from the reservoir increased POC content. The distribution of river-laden POC at the river mouth was modulated by plume dynamics and deposition of coarse-grained sediments.
Article
Environmental Sciences
K. Wang, K. Yin
Summary: The research revealed that the presence of riverine plumes acts as a barrier to weaken deep water upwelling, thereby reducing the upward transport of nutrients. Vertical profiles taken in the Northern South China Sea in July 2002 showed a three-layer structure, with the middle layer influenced by the plume weakening the intensity of upwelling.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2021)
Article
Environmental Sciences
Yanru He, Yihe Wang, Hui Wu
Summary: The effects of large-scale engineering projects in river estuaries on surrounding coastal waters have been less emphasized. This study uses the Changjiang River Estuary as an example to show that such projects can have significant consequences. The research analyzes the variations of algal blooms in the estuary and its adjacent water using harmful algal bloom events data and chlorophyll satellite data. It is found that the location of algal bloom hotspot changed with the construction of the estuary. A numerical model indicates that the redistribution of nutrient concentration and turbidity caused by river plume deviation is responsible for the shift in high chlorophyll concentration area. The direct impact of the Three Gorges Dam is found to be less important than expected. Therefore, caution should be exercised when interpreting hydrodynamic and ecological changes outside the estuary during the same period as these projects.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Engineering, Marine
Nazanin Chaichitehrani, Chunyan Li, Kehui Xu, Erin L. Hestir, Mohammad Nabi Allahdadi
Summary: A coupled Flow-Wave-Sediment model was used to study the hydrodynamics, sedimentation, and bottom boundary layer dynamics over the Sandy Point Dredge Pit (SPDP) in the northern Gulf of Mexico. The presence of SPDP decreased surface current speed while its effect on wave characteristics was minor. Sediments from the Mississippi River contributed significantly to the sedimentation over the SPDP.
Article
Engineering, Environmental
G. Shiravani, D. Oberrecht, L. Roscher, S. Kernchen, M. Halbach, M. Gerriets, B. M. Scholz-Bottcher, T. H. Badewien, A. Wurpts
Summary: Microplastic (MP) pollution poses a significant challenge to both human life and the natural system. The irresponsible handling of plastics in daily life has led to a rapid contamination of air, water, and soil with MP. This study focuses on the modeling of MP transport and interaction with fine sediment in estuarine turbidity zones (ETZ), proposing a new approach to improve the formulation of MP settling velocity in these conditions. The model results indicate higher concentrations of MP in ETZ, both in the water column and the bed sediment, which is supported by measurements. Additionally, the model suggests that smaller MP particles are more likely to escape the ETZ and move towards the open sea.
Article
Environmental Sciences
Paolo Filippucci, Luca Brocca, Stefania Bonafoni, Carla Saltalippi, Wolfgang Wagner, Angelica Tarpanelli
Summary: River monitoring is a challenging issue, but the use of satellite sensors, such as those from Sentinel-2, has greatly improved river discharge estimation. This study investigates the potential of Sentinel-2 NIR reflectances in improving river discharge estimation and evaluates its accuracy using in-situ observations from Italian rivers. The results demonstrate the effectiveness of high-resolution images in estimating river discharges.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Geosciences, Multidisciplinary
Silke A. J. Tas, Dirk S. van Maren, Ad J. H. M. Reniers
Summary: In this paper, the formation of cheniers through wave winnowing is explored using Delft3D. The study identifies three phases of chenier development: winnowing phase, sand transport phase, and crest formation phase. The main driving mechanism for onshore sand transport is wave asymmetry. Chenier formation does not require extreme storm conditions and is a relatively slow process.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2022)
Article
Environmental Sciences
Katie E. Hughes, Amanda Wild, Eva Kwoll, Marten Geertsema, Alexandra Perry, K. Darcy Harrison
Summary: This study used remote sensing imagery, topographic surveys, and field observation to investigate a retrogressive landslide near a tributary to the Peace River in British Columbia. The landslide delivered a significant amount of sediment to the river annually and high plume activity was found to be related to increased groundwater pressure. Monitoring using readily available imagery is a feasible method for tracking the activity of this recurring landslide.
Article
Environmental Sciences
Jinyang Wang, Yoeri M. M. Dijkstra, Huib E. de Swart
Summary: The aim of this study is to understand the processes that determine the dynamics of estuarine turbidity maximum (ETM) in channel networks. It is found that the ETM dynamics in a network is coupled, with changes in one channel affecting the ETM pattern in all channels. Additionally, the deepening or narrowing of a seaward channel can influence the ETMs in the entire network.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Oceanography
Dongxue Yu, Guangxuan Han, Xiaojie Wang, Baohua Zhang, Franziska Eller, Jinying Zhang, Mingliang Zhao
Summary: The study on the Yellow River Delta wetlands found that their evolution is influenced by runoff, sediment load, and human activities, resulting in a decrease in natural wetlands converted into human-made wetlands and non-wetlands.
OCEAN & COASTAL MANAGEMENT
(2021)
Article
Geosciences, Multidisciplinary
Masashi Watanabe, Kazuhisa Goto, Tomoya Abe
Summary: Field surveys after the 2011 Tohoku-oki tsunami revealed that mud tsunami deposits can reach close to the inundation limit, but the factors influencing their distribution were unclear. By simulating sand and mud transport and analyzing sensitivity to various parameters, we found that the presence of terrestrial mud sources and a gentle topographic slope are necessary for mud deposits to cover the entire inundation distance.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2023)
Article
Environmental Sciences
C. E. Renshaw, E. N. Dethier, J. D. Landis, J. M. Kaste
Summary: The input of organic matter into stream channels is an important energy source for headwater ecosystems and plays a crucial role in the global carbon cycle. The study focuses on quantifying the mobilization, transport, and storage of organic-rich fine sediment in a Strahler fourth-order stream during intermediate-sized storm events. It is found that the channel bed is consistently a source of suspended load to the channel margins, and the trapping of suspended load by riparian margins limits sediment transport distance and decouples the channel from local terrestrial organic matter exchange.
WATER RESOURCES RESEARCH
(2022)
Article
Engineering, Environmental
Wenjing Fu, Yuanzhi Qi, Chunle Luo, Hongmei Zhang, Xuchen Wang
Summary: Black carbon (BC), a group of environmentally concentrated organic pollutants, is widely distributed in marine sediments. However, the fate and transformation of BC in marine sediments have not been well studied. Through radiocarbon measurements, it was found that there are two distinct BC pools in the sediments, with ancient ages in the solid-phase BC (SBC). The modern biomass-derived BC contributes to most of the dissolved BC (DBC) pool, while fossil material-produced BC forms the majority of the SBC pools. The discrepancy between modern and dead BC contributions is associated with the BC budget after particulate BC (PBC) deposition, where a significant portion of PBC is transferred to porewater as DBC and the rest is sequestrated as SBC in sediments.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Marine
Alba Ricondo, Laura Cagigal, Beatriz Perez-Diaz, Fernando J. Mendez
Summary: This research presents a site-specific metamodel based on the SWASH numerical model simulations, which can predict coastal hydrodynamic variables in a fast and efficient manner. The metamodel uses downscaled and dimensionality reduced synthetic database to accurately reproduce wave setup, wave heights associated with different frequency bands, and wave runup. This method has great potential in coastal risk assessments, early warning systems, and climate change projections.
Article
Engineering, Marine
Xiao Yu, Wangjun Ren, Bukui Zhou, Li Chen, Xiangyun Xu, Genmao Ren
Summary: This study investigated and compared the compression responses and energy absorption capacities of coral sand and silica sand at a strain rate of approximately 1000 s-1. The results showed that coral sand had significantly higher energy absorption capacity than silica sand due to its higher compressibility. The study findings suggest that using poorly graded coral sand can improve its energy absorption capacity.
Article
Engineering, Marine
Jingxi Zhang, Junmin Mou, Linying Chen, Pengfei Chen, Mengxia Li
Summary: This paper proposes a cooperative control scheme for ship formation tracking based on Model Predictive Control. A predictive observer is designed to estimate the current motion states of the leader ship using delayed motion information. Comparative simulations demonstrate the effectiveness and robustness of the proposed controller.
Article
Engineering, Marine
Yu Yao, Danni Zhong, Qijia Shi, Ji Wu, Jiangxia Li
Summary: This study proposes a 2DH numerical model based on Boussinesq equations to investigate the impact of dredging reef-flat sand on wave characteristics and wave-driven current. The model is verified through wave flume experiments and wave basin experiments, and the influences of incident wave conditions and pit morphological features on wave characteristics are examined.
Article
Engineering, Marine
Jayanta Shounda, Krishnendu Barman, Koustuv Debnath
Summary: This study investigates the double-average turbulence characteristics of combined wave-current flow over a rough bed with different spacing arrangements. The results show that a spacing ratio of p/r=4 offers the highest resistance to the flow, and the double-average Reynolds stress decreases throughout the flow depth. The advection of momentum-flux of normal stress shows an increase at the outer layer and a decrease near the bed region after wave imposition. Maximum turbulence kinetic energy production and diffusion occur at different layers. The turbulence structure is strongly anisotropic at the bottom region and near the outer layer, with a decrease in anisotropy observed with an increase in roughness spacing.
Article
Engineering, Marine
Meng Zhang, Lianghui Sun, Yaoguo Xie
Summary: The research proposes a method for online identification of wave bending and torsional moment in hull structures. For structures without large openings, the method optimizes sensor positions and establishes a mathematical model to improve accuracy. For structures with large openings, a joint dual-section monitoring method is proposed to simultaneously identify bending and torsional moments in multiple key cross sections.
Article
Engineering, Marine
Longming Chen, Shutao Li, Yeqing Chen, Dong Guo, Wanli Wei, Qiushi Yan
Summary: This study investigated the dynamic response characteristics and damage modes of pile wharves subjected to underwater explosions. The results showed that the main damaged components of the pile wharf were the piles, and inclined piles had a higher probability of moderate or more significant damage compared to vertical piles. The study also suggested that replacing inclined piles with alternative optimized structures benefits the blast resistance of pile wharves.
Article
Engineering, Marine
I. -C Kim, G. Ducrozet, V. Leroy, F. Bonnefoy, Y. Perignon, S. Bourguignon
Summary: Previous research focused on the accuracy and efficiency of short-term wave fields in specific prediction zones, while we developed algorithms for continuous wave prediction based on the practical prediction zone and discussed important time factors and strategies to reduce computational costs.
Article
Engineering, Marine
Hang Xie, Xianglin Dai, Fang Liu, Xinyu Liu
Summary: This study investigates the load characteristics of a three-dimensional stern model with pitch angle through a drop test, and reveals complex characteristics of pressure distribution near the stern shaft. The study also shows that the vibration characteristics of the load are influenced by the drop height and pitch angle, with the drop height having a greater effect on the high-frequency components.
Article
Engineering, Marine
Hangyuan Zhang, Wanli Yang, Dewen Liu, Xiaokun Geng, Wangyu Dai, Yuzhi Zhang
Summary: The deep-water bridge is more vulnerable to earthquake damage than the bridge standing in air. The larger blocking ratio has a significant impact on the added mass coefficient, which requires further comprehensive study. The generation mechanism of block effect is analyzed using numerical simulation software ANSYS Fluent. The results show that the recirculation zone with focus reduces the pressure on the back surface of the cylinder, resulting in the peak value of in-line force not occurring synchronously with the peak value of acceleration. The change in position and intensity of the recirculation zone with focus, as well as the change in water flow around the cylinder surface, are identified as the generation mechanism of the block effect, which has a 10% influence on the hydrodynamic force. The changing rule of the added mass coefficient with blocking ratio is discussed in detail, and a modification approach to the current added mass coefficient calculation method is suggested. Physical experiments are conducted to validate the modification approach, and the results show that it is accurate and can be used in further study and real practice.
Article
Engineering, Marine
Golnesa Karimi-Zindashti, Ozgur Kurc
Summary: This study examines the performance of an in-house code utilizing a deterministic vortex method on the rotation of circular and square cylinders. The results show that rotational motion reduces drag forces, suppresses fluctuating forces, and increases lift forces. The code accurately predicts vortex shedding suppression and identifies the emergence of near-field wakes in the flow over rotating square cylinders.
Article
Engineering, Marine
George Dafermos, George Zaraphonitis
Summary: The survivability of damaged ships is of great importance and the regulatory framework is constantly updated. The introduction of the probabilistic damage stability framework has rationalized the assessment procedure. Flooding simulation tools can be used to investigate the dynamic response of damaged ships.
Article
Engineering, Marine
Xuyue Chen, Xu Du, Chengkai Weng, Jin Yang, Deli Gao, Dongyu Su, Gan Wang
Summary: This paper proposes a real-time drilling parameters optimization method for offshore large-scale cluster extended reach drilling based on intelligent optimization algorithm and machine learning. By establishing a ROP model with long short-term memory neurons, and combining genetic algorithm, differential evolution algorithm, and particle swarm algorithm, the method achieves real-time optimization of drilling parameters and significantly improves the ROP.
Article
Engineering, Marine
Sung-Jae Kim, Chungkuk Jin, MooHyun Kim
Summary: This study investigates the dynamic behavior of a moored submerged floating tunnel (SFT) under tsunami-like waves through numerical simulations and sensitivity tests. The results show that design parameters significantly affect the dynamics of the SFT system and mooring tensions, with shorter-duration and higher-elevation tsunamis having a greater impact.
Article
Engineering, Marine
G. Clarindo, C. Guedes Soares
Summary: Environmental contours are constructed using the Inverse-First Order Reliability Method based on return periods. The paper proposes the use of the Burr distribution to model the marginal distribution of long-term significant wave heights. The newly implemented scheme results in different environmental contours compared to the reference approach.