Journal articles: 'Restricted waterways'

1

MANDLER, MARC B., MYRIAM W. SMITH, and JAMES W. GYNTHER. "Precision Electronic Navigation in Restricted Waterways." Navigation 37, no. 4 (December 1990): 319–27. http://dx.doi.org/10.1002/j.2161-4296.1990.tb01559.x.

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Hoa, Nguyen Thi Ngoc, Vu Ngoc Bich, Tran Ngoc Tu, Nguyen Manh Chien, and Le Tat Hien. "Numerical Investigating the Effect of Water Depth on Ship Resistance Using RANS CFD Method." Polish Maritime Research 26, no. 3 (September 1, 2019): 56–64. http://dx.doi.org/10.2478/pomr-2019-0046.

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Abstract On inland waterways the ship resistance and propulsive characteristics are strictly related to the depth of the waterway, thus it is important to have an understanding of the influence of water depth on ship hydrodynamic characteristics. Therefore, accurate predictions of hydrodynamic forces in restricted waterways are required and important. The aim of this paper is investigating the capability of the commercial unsteady Reynolds–Averaged Navier–Stokes (RANS) solver to predict the influence of water depth on ship resistance. The volume of fluid method (VOF) is applied to simulate the free surface flow around the ship. The hull resistance in shallow and deep water is compared. The obtained numerical results are validated against related experimental studies available in the literature.

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Bunyaga, Aloyce, Rene Corner-Thomas, Ina Draganova, Paul Kenyon, and Lucy Burkitt. "The Behaviour of Sheep around a Natural Waterway and Impact on Water Quality during Winter in New Zealand." Animals 13, no. 9 (April 25, 2023): 1461. http://dx.doi.org/10.3390/ani13091461.

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Access of livestock, such as cattle, to waterways has been shown to be a cause of poor water quality due to pugging damage and excretion entering the water. In New Zealand, regulations require that cattle, deer, and pigs are excluded from accessing waterways, but there are no such requirements for sheep. The current study utilised 24 h video cameras, global positioning system units, and triaxial accelerometers to observe the interaction of Romney ewes (n = 40) with a natural waterway. Ewes were either restricted (week 1) or given access to a reticulated water trough (week 2). Proximity data showed that ewes spent more time within 3 m of the waterway when the trough was unrestricted than when restricted (14.1 ± 5.7 and 10.8 ± 5.1 min/ewe/day, respectively; p < 0.05). Ewes travelled shorter distances on the steeper areas of paddock than flatter areas. Similarly, ewes showed a spatial preference for the flat and low sloped areas of the paddock. Concentrations of suspended sediment and total phosphorus were higher during access to a reticulated water trough which coincided with the week with more rainy days. Phosphorus and E. coli concentrations in the stream water samples were the above recommended Australian and New Zealand Environment and Conservation Council water quality guidelines, especially after rainy days, but did not appear to be directly related to sheep activity. Overall, the results suggest that during winter, ewes interacted very little with the waterway and were thus unlikely to influence the levels of nutrient and pathogens in the waterway.

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Liu, Jingxian, Feng Zhou, Zongzhi Li, Maoqing Wang, and Ryan Wen Liu. "Dynamic Ship Domain Models for Capacity Analysis of Restricted Water Channels." Journal of Navigation 69, no. 3 (October 29, 2015): 481–503. http://dx.doi.org/10.1017/s0373463315000764.

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Developing adequate ship domain models may significantly benefit vessel navigation safety. In essence, navigation safety is collectively affected by the navigable waterway condition, the size and shape of the ship, and operators' skills. The existing ship domains mainly use constant values for the model input parameters, making them incapable of handling site-specific conditions. This study proposes dynamic ship domain models that take into consideration navigable waterway conditions, ship behaviours, ship types and sizes, and operators' skills in a holistic manner. Specifically, the conditions of restricted waterways are classified into navigating along the channel, crossing the channel, joining another flow and turning. The ship types considered include ships that transport non-hazardous goods and Liquid Natural Gas (LNG) ships that are in need of additional security zones. A computational experiment is conducted for model application using data on water channel design and ship traffic volumes related to navigating along the channel, joining another flow and turning. Comparisons of results obtained between the proposed dynamic models with real ship traffic counts reveal that the proposed models could achieve a higher level of accuracy in estimating the capacity of restricted water channels. It therefore could potentially deliver safety enhancements of waterway transportation.

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Gucma, Lucjan, and Zbigniew Pietrzykowski. "Ship Manoeuvring in Restricted Areas: An Attempt to Quantify Dangerous Situations Using a Probabilistic-Fuzzy Method." Journal of Navigation 59, no. 2 (April 6, 2006): 251–62. http://dx.doi.org/10.1017/s037346330600364x.

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This paper presents a practical application of the probabilistic-fuzzy method for assessment of the safety of a ship manoeuvring in waterways. The method, based on probabilistic risk analysis and elements of fuzzy logic, takes into account situations of threatened navigational safety and situations when a navigator intuitively thinks that the safety of manoeuvring ship is threatened. The probability of grounding a ship manoeuvring in a waterway bend is determined by means of simulation method. Then, with the use of experts' knowledge and tools of fuzzy logic the probability of a dangerous situation is determined. Two different approaches are applied for the determination of that probability. The results are compared.

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Gan, Shaojun, Yanxia Wang, Kang Li, and Shan Liang. "Efficient online one-way traffic scheduling for restricted waterways." Ocean Engineering 237 (October 2021): 109515. http://dx.doi.org/10.1016/j.oceaneng.2021.109515.

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Alderf, N., E. Lefranĉois, P. Sergent, and P. Debaillon. "Transition effects on ship sinkage in highly restricted waterways." Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 224, no. 2 (December 2, 2009): 141–53. http://dx.doi.org/10.1243/14750902jeme170.

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Varyani, K. S. "Squat effects on high speed craft in restricted waterways." Ocean Engineering 33, no. 3-4 (March 2006): 365–81. http://dx.doi.org/10.1016/j.oceaneng.2005.04.016.

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Sergent, P., E. Lefrançois, and N. Mohamad. "Virtual bottom for ships sailing in restricted waterways (unsteady squat)." Ocean Engineering 110 (December 2015): 205–14. http://dx.doi.org/10.1016/j.oceaneng.2015.10.017.

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Xin, Xuri, Kezhong Liu, Jinfen Zhang, Shuzhe Chen, Hongbo Wang, and Zhiyou Cheng. "A Self-Organizing Grouping Approach for Ship Traffic Scheduling in Restricted One-Way Waterway." Marine Technology Society Journal 53, no. 1 (January 1, 2019): 83–96. http://dx.doi.org/10.4031/mtsj.53.1.9.

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AbstractShip scheduling optimization is one of the most effective ways to eliminate the bottlenecks of waterway transportation, especially in restricted one-way waterways. In this study, a novel scheduling model called self-organizing grouping is proposed to minimize two types of delay time, which are the waiting time and the extra navigation time caused by speed reduction. The proposed model schedules ships in an iterative way based on the distributed scheduling mode. To alleviate the impact of local scheduling on the overall traffic efficiency, a grouping method is proposed, in which the ships are divided into different groups based on their arrival time interval. Moreover, the ships in the same group are scheduled to minimize the interferences among them by incorporating a grouping improvement strategy. The strategy is used to deal with the influence of ships with very small speed. Experiments are carried out by comparing the proposed model with the first-come-first-serve model and the ship self-organizing cooperation model. Simulation results show that the delay time is reduced by 25%‐30% and approximately by 5% compared with that from the two models, respectively. Such advantage also exists for different combinations of ship traffic parameters. In addition, long-distance sailing with limited speed can be avoided using the proposed method, which is beneficial to relieve waterway traffic congestion.

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ILLES, Ladislav, Martin JURKOVIC, Tomas KALINA, Piotr GORZELANCZYK, and Vladimir LUPTAK. "Methodology for optimising the hull shape of a vessel with restricted draft." Scientific Journal of Silesian University of Technology. Series Transport 110 (March 1, 2021): 59–71. http://dx.doi.org/10.20858/sjsutst.2021.110.5.

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Increasing transport volumes on Europe's inland waterways is a major reason for improving the quality and reliability of internationally important waterways. Continued navigation restrictions due to restricted draft (draught) led to the search for new design solutions. Such solutions enable navigation even under critical navigation conditions. Restricted draft is one of the most important limitations that hinder navigation, especially in the summer. The main objective of the construction of an inland vessel is to obtain a shape that will achieve optimum performance with as little resistance as possible. A shape that will be able to navigate at a limited depth. Presently, there is no clearly defined methodology as a procedure for optimising the hull. When solving theoretical problems of shipbuilding character and ship calculations, it is necessary to consider the basic theory of the ship with special regard to the latest methodological procedures of related scientific disciplines. This paper presents a methodology that considers all the basic aspects of optimisation tasks in ship design and construction.

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Lee, Chun-Ki. "Numerical study of hydrodynamic interaction on a vessel in restricted waterways." International Journal of Naval Architecture and Ocean Engineering 4, no. 1 (March 2012): 1–9. http://dx.doi.org/10.2478/ijnaoe-2013-0073.

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13

Zhang, Jinfen, Tiago A. Santos, C. Guedes Soares, and Xinping Yan. "Sequential ship traffic scheduling model for restricted two-way waterway transportation." Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 231, no. 1 (August 3, 2016): 86–97. http://dx.doi.org/10.1177/1475090215621580.

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A good ship traffic scheduling mode can enhance traffic efficiency to a large degree, especially in restricted waterways such as approach channel of ports and straits. A ship scheduling model for restricted two-way waterways is proposed in this article. The assumption is made in the model that two-way transportation is not allowed for cases in which there is at least one large ship. Based on this assumption, a mathematical model is proposed to minimize the weighted average of the mean and the maximum waiting time given several safety restrictions. A sequential scheduling algorithm is proposed to solve such problem, in which the ships are divided into rounds. The ships in each round are scheduled simultaneously to enhance traffic efficiency by the trade-off between the priorities of small and large ships. Experiments are carried out by comparing sequential scheduling method with first-come-first-serve model. The results indicate that the proposed algorithm can reduce ships’ waiting time, whereas a lot of ships need to wait for long time with first come first serve. The distinctions are more evident with a higher proportion of large ships, and the proposed algorithm can keep ships’ waiting time to an acceptable level.

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Grabowski, Martha. "Decision Support to Masters, Mates on Watch, and Pilots: The Piloting Expert System." Journal of Navigation 43, no. 03 (September 1990): 364–84. http://dx.doi.org/10.1017/s0373463300014004.

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Piloting large vessels in increasingly congested waterways is no simple task. As in many ‘decision-making under uncertainty’ scenarios, masters, mates and pilots engaged in piloting are inundated with much information and required to make crucial decisions in real time. Piloting is also an inherently judgmental activity. Pilots and ships' captains invariably develop heuristics for transiting particular waterways. As vessels become larger, cargoes more hazardous, and the waterways more congested, decision aid technology is being considered to improve piloting decision-making. This paper describes one approach to providing improved on-board decision support to masters, mates on watch, and pilots navigating in restricted waters. We discuss (1) the use of cognitive decision aids in piloting, (2) the design of such a decision aid developed for New York harbour, (3) simulator experiments evaluating the expert system, and (4) plans to apply the approach and ‘lessons learned’ to the development of an expert system for tankers transiting the Gulf of Alaska.

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Inoue, Kinzo. "Evaluation Method of Ship-handling Difficulty for Navigation in Restricted and Congested Waterways." Journal of Navigation 53, no. 1 (January 2000): 167–80. http://dx.doi.org/10.1017/s0373463399008541.

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This paper develops a quantitative model for evaluating the difficulty of ship-handling caused by a restricted manoeuvring area or by traffic congestion or by a combination of both. It includes acceptance criteria based on the mariner's perception of safety. An attempt is made to evaluate the model by applying it to the specific environmental conditions of major ports in Japan. The model can provide information on the degree of ship-handling difficulty and so enable better design of infrastructure for waterways.

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Wang, Hongbo, Wuliu Tian, Jinfen Zhang, and Yongjiang Li. "A HYBRID SELF-ORGANIZING SCHEDULING METHOD FOR SHIPS IN RESTRICTED TWO-WAY WATERWAYS." Brodogradnja 71, no. 2 (April 1, 2020): 15–30. http://dx.doi.org/10.21278/brod71202.

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17

Ji, Shengcheng, Abdellatif Ouahsine, Hassan Smaoui, and Philippe Sergent. "3D numerical simulation of ship-induced waves and sediment transport in restricted waterways." La Houille Blanche, no. 6 (December 2014): 68–73. http://dx.doi.org/10.1051/lhb/2014065.

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18

Lee, Chun-Ki, and Sam-Goo Lee. "The assessment of safe navigation regarding hydrodynamic forces between ships in restricted waterways." Journal of Mechanical Science and Technology 20, no. 11 (November 2006): 2002–9. http://dx.doi.org/10.1007/bf03027593.

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19

Alderf, N., E. Lefrançois, P. Sergent, and P. Debaillon. "Dynamic ship response integration for numerical prediction of squat in highly restricted waterways." International Journal for Numerical Methods in Fluids 65, no. 7 (February 1, 2011): 743–63. http://dx.doi.org/10.1002/fld.2194.

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Yao, Jian-xi, and Zao-jian Zou. "Calculation of ship squat in restricted waterways by using a 3D panel method." Journal of Hydrodynamics 22, S1 (October 2010): 472–77. http://dx.doi.org/10.1016/s1001-6058(09)60241-9.

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Landsburg, Alexander C., Roderick A. Barr, Larry Daggett, Wei-Yuan Hwang, Bent Jakobsen, Mike Morris, and Lou Vest. "Critical Needs for Ship Maneuverability: Lessons From the Houston Ship Channel Full-Scale Maneuvering Trials." Marine Technology and SNAME News 42, no. 01 (January 1, 2005): 11–20. http://dx.doi.org/10.5957/mt1.2005.42.1.11.

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"I think the architects and engineers that design ships for the sea, where they spend 99% of their time, forget that at some point they still have to get up the ditches to load or discharge their cargo. Someday when a high-profile accident does occur, ship builders might even be brought into the civil arena and found criminally negligent and liable for building underpowered and poor handling ships."A pilot's view The Standards for Ship Maneuverability approved by the International Maritime Organization (IMO) in 2002 represent a significant step forward in ensuring adequate maneuverability of ships. The Standards provide numerical criteria for assessing the adequacy of maneuverability in deep, unrestricted water at sea speed. Explanatory notes to the Standards provide useful guidelines to the assessment and validation process that help with various issues, such as adjusting full-scale trial results for environmental and loading conditions. Major issues exist, however. In question is the ability of the standards to ensure adequate maneuverability in shallow, restricted, and congested waterways under vessel meeting and passing conditions with the interaction effects, bank suction, and other situations that are encountered in normal port, harbor, and waterway operations. Historically, even in shallow water that is unrestricted, only a couple of ship trials have ever been conducted due to the great cost to prepare for such tests. The lack of accurate full-scale data has seriously limited the accuracy capable of being built into mathematical prediction models. Recently, however, revolutionary positioning technology has enabled collecting highly accurate track and vertical position data on ships operating in shallow and restricted water, with and without interacting ship traffic. Accurate mathematical modeling of ship operations in complex harbors and waterways has become a critical need, and now the possibility of advancing the science finally exists. With accurate full-scale trials data and improved prediction techniques, such as computational fluid dynamics, such ability now seems attainable.

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Lee, Chun-Ki. "Assessment of Safe Navigation Including the Effect of Ship-Ship Interaction in Restricted Waterways." Journal of Navigation and Port Research 27, no. 3 (August 1, 2003): 247–52. http://dx.doi.org/10.5394/kinpr.2003.27.3.247.

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Zhang, Zhi-hong, Hui Deng, and Chong Wang. "Analytical models of hydrodynamic pressure field causing by a moving ship in restricted waterways." Ocean Engineering 108 (November 2015): 563–70. http://dx.doi.org/10.1016/j.oceaneng.2015.08.046.

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Jerzyło, Patrycja, and Aleksandra Wawrzyńska. "Hazard identification of factors affecting the operational safety of the ship on inland waterways in the Vistula delta." WUT Journal of Transportation Engineering 121 (June 1, 2018): 115–24. http://dx.doi.org/10.5604/01.3001.0014.4572.

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Every year in Poland, on the inland waterways, accidents and incidents are registered by the Offshore Shipping Offices, the State Fire Service and the Police. Improving the level of security requires indepth analysis and drawing conclusions from emerging emergency situations. It is important to identify and systematize the threats occurring in inland waterway, which will allow for the selection of effective methods of counteracting them and increasing the level of safety on restricted waters. The aim of the work is to analyze the course of proceedings when conducting the analysis of identification of threats affecting the safety of ship operation and analysis of the source and consequences of accidents and incidents that took place on the inland waterway in the Vistula delta in recent years. The course of action in solving the research problem posed involves three stages: an analysis of the current state, hazard identification and model verification. Knowledge of the causes and consequences of accidents in inland navigation may be used to create safety standards and procedures, as well as to improve their functioning. It is very desirable to eliminate similar adverse events in the future. One of the methods al-lowing for the detection and proper verification of sources, course and consequences of events occurring in inland navigation is the analysis of sources of causes and consequences. It allows the identification of initiating agents and a further sequence of events, which in turn contributes to the improvement of the level of navigational safety.

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Lee, Chun Ki. "The Interaction Effects Between Two Vessels in the Proximity of Bank Wall in Restricted Waterways." Journal of Korean navigation and port research 29, no. 1 (February 1, 2005): 17–22. http://dx.doi.org/10.5394/kinpr.2005.29.1.017.

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Sariöz, K., and E. Narli. "Assessment of manoeuvring performance of large tankers in restricted waterways: a real-time simulation approach." Ocean Engineering 30, no. 12 (August 2003): 1535–51. http://dx.doi.org/10.1016/s0029-8018(02)00142-7.

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27

Gray, William O., Jennifer K. Waters, Alan L. Blume, and Alexander C. Landsburg. "Channel Design and Vessel Maneuverability: Next Steps." Marine Technology and SNAME News 40, no. 02 (April 1, 2003): 93–105. http://dx.doi.org/10.5957/mt1.2003.40.2.93.

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A recent workshop on channel design and vessel maneuverability brought together channel designers, naval architects, pilots, and ship operators to review and share design approaches and standards that affect safety of operations. The desire was to develop policy recommendations that can be implemented both in the way channels are laid out and enlarged and how ships of various types using them should be designed and handled. Resulting recommendations based on the discussions promise to improve overall safety of ship operations in restricted waterways.

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Manley, Nicole A. L. "Importance of Tacit Knowledge in Geoscience Brought to the Surface through Artistic Methods." Art/Research International: A Transdisciplinary Journal 7, no. 1 (March 26, 2022): 123–55. http://dx.doi.org/10.18432/ari29571.

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This study of scientists’ reactions to the experience of an art exhibition, researches Polyani’s (2009) tacit knowing, a knowledge that we cannot easily express into words, and Deleuze and Guattari’s (1987) striated and smooth spaces, with striated being a channelled and restricted way of thinking compared to smooth as free flowing and creative. To research these concepts, a psycho-social method—the Visual Matrix (VM)—is used as a research method. Two groups of geoscientists were brought together to first view Waterways, an art exhibition, and then participate in a VM. The research concludes that the scientists were able to express tacit knowledge elicited through the experience of Waterways, enabling them to think differently about their work and form new understandings about the natural environment in relationship to themselves and society. For artists, the VM can be an effective tool when working with scientists and the public. The study argues the importance of bringing tacit knowledge to the surface, allowing greater possibility of combining scientific and artistic approaches.

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Liu, Kezhong, Xuri Xin, Jie Ma, Jinfen Zhang, and Qing Yu. "Sensitivity analysis of ship traffic in restricted two-way waterways considering the impact of LNG carriers." Ocean Engineering 192 (November 2019): 106556. http://dx.doi.org/10.1016/j.oceaneng.2019.106556.

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Linde, Florian, Abdellatif Ouahsine, Nicolas Huybrechts, and Philippe Sergent. "Three-Dimensional Numerical Simulation of Ship Resistance in Restricted Waterways: Effect of Ship Sinkage and Channel Restriction." Journal of Waterway, Port, Coastal, and Ocean Engineering 143, no. 1 (January 2017): 06016003. http://dx.doi.org/10.1061/(asce)ww.1943-5460.0000353.

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Karetnikov, Vladimir, Gleb Chistyakov, and Evgeniy Ol’khovik. "Tasks of developing the aquatory for testing autonomus ships in inland waterways." E3S Web of Conferences 157 (2020): 02010. http://dx.doi.org/10.1051/e3sconf/202015702010.

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For successful implementation of unmanned technologies on water transport, it is proposed to create a specialized test area where autonomus ships and technologies of autonomus navigation could be tested in real conditions. The paper considers the solution of the problem of placement and technical equipment of the test aquatory, provided that risks are minimized, including collision prevention and environmental damage. To select the location of this aquatory, the features of the inland waterways of the European part of the Russian Federation were analyzed and the requirements for this water area were formulated. As a result, two test sites were proposed that allow for all the necessary types of tests of autonomus ships. The paper synthesizes the main parameters, such as the availability of navigation and hydrographic information, electronic cartography, etc. As a result of the study, a site in lake Ladoga was selected. In order to complete the full cycle of necessary measures during the tests and ensure the safety of navigation in a given area, it was decided to design the test aquatory as a set of three maneuvering zones for an unmanned vessel: the safe free maneuvering zone during testing, the turning zone - area of restricted maneuverability on courses and speeds, as well as on the shift of the steering wheel, and the extra safety maneuvering area used to prevent navigation accidents in difficult navigation conditions. The proposed location and concept of the test aquatory fully meet all the requirements for such an innovative infrastructure at the international level.

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Beatty, Stephen J., David L. Morgan, Mahmoud Rashnavadi, and Alan J. Lymbery. "Salinity tolerances of endemic freshwater fishes of south-western Australia: implications for conservation in a biodiversity hotspot." Marine and Freshwater Research 62, no. 1 (2011): 91. http://dx.doi.org/10.1071/mf10100.

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Secondary salinisation represents an important threat to terrestrial and aquatic habitats throughout the world. In south-western Australia, widespread salinisation of waterways has caused large range reductions in the highly endemic freshwater fish fauna. We hypothesised that differences in the distributions of three fish species within the salinised Blackwood River would be related to their salinity tolerances. Galaxias occidentalis was widespread throughout the catchment, whereas Nannoperca vittata was restricted to the main channel and freshwater tributaries of the lower catchment, and Nannatherina balstoni was restricted to those tributaries and a perennial section of the main channel that received a considerable amount of fresh groundwater. Acute salinity tolerances (Effect Concentrations) of G. occidentalis and N. vittata were similar (EC50 ∼14.6 g L–1), but significantly greater than that of N. balstoni (EC50 ∼8.2 g L–1). The greater geographical range of G. occidentalis, compared with N. vittata, may be a consequence of the dispersal capability of the former species, and the lower salinity tolerance of N. balstoni contributes to its highly restricted range. The findings demonstrate that secondary salinisation has greatly impacted these freshwater fishes, and fresh groundwater refuges, predicted to decrease due to reduced rainfall, appear crucial in maintaining remnant populations.

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Kazerooni, Mohammadreza Fathi, Masoud Rahimian, Marcus Tree, Tim Womersley, Simon Brandi Mortensen, and Bugge Jensen. "Development and Validation of an Operational Fast Time Ship Manoeuvring Solver to Increase Navigation Efficiency in Horizontally Restricted Waterways." TransNav, the International Journal on Marine Navigation and Safety of Sea Transportation 17, no. 1 (2023): 71–76. http://dx.doi.org/10.12716/1001.17.01.06.

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Brodie, Jon E., and Alan W. Mitchell. "Nutrients in Australian tropical rivers: changes with agricultural development and implications for receiving environments." Marine and Freshwater Research 56, no. 3 (2005): 279. http://dx.doi.org/10.1071/mf04081.

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In tropical Australia, intensive studies of river suspended sediment (SS) and nutrient dynamics have been restricted to streams on the north-east coast between the Fitzroy and Normanby Rivers (Queensland), Magela Creek/East Alligator River (Northern Territory) and the Ord River (Western Australia). Historical conditions in these rivers were probably characterised by low–moderate SS concentrations and low concentrations of dissolved inorganic nitrogen and phosphorus in flow events. Introduction of agriculture has transformed SS and nutrient dynamics. Grazing has led to soil erosion and increased SS and particulate nutrient concentrations and fluxes in event flows. Fertilised cropping has increased nutrient inputs to catchments, where it forms a substantial proportion of the catchment area. Consequently, both particulate and dissolved inorganic nutrient concentrations and fluxes have increased. Australian tropical rivers have episodic flows, with most material transport occurring during large flow events. The restricted period of these highly energetic flows means little trapping of materials in waterways occurs. Loads are transported efficiently downstream and processes such as denitrification and in-channel sedimentation may be of limited importance. Owing to excessive nutrient inputs associated with agriculture, a number of northern freshwater, estuarine and coastal ecosystems are now eutrophic. Continued development, especially fertilised cropping, without adequate management of nutrient losses is likely to exacerbate these problems.

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Zheng, Ziqiang, Lu Zou, and Zaojian Zou. "A Numerical Study on the Effects of Ship-Generated Waves on a Moored Ship in Restricted Waterways Considering Initial Acceleration Process." Journal of Marine Science and Engineering 11, no. 3 (February 23, 2023): 483. http://dx.doi.org/10.3390/jmse11030483.

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In order to develop a reliable numerical method to investigate the effects of ship-generated waves on a moored ship in restricted waterways, this paper takes the MASHCON2022 benchmark model test case as the study object and simulates the whole process of a ship passing a moored ship by using the unsteady Reynolds-Averaged Navier-Stokes (URANS) method coupled with the dynamic overset mesh technique. The initial acceleration process of the passing ship before approaching the moored ship is considered in the numerical simulations to reproduce the benchmark model tests more realistically. The numerical simulations with four acceleration modes are conducted. The comparisons among the numerical results and the test data verify that the prediction accuracy considering the acceleration process is obviously higher than that without the acceleration process, especially for the solitary wave system, and the results based on the linear acceleration agree with the test data best. The flow field results indicate that the impacts of the solitary wave system and the primary wave system on the moored ship are different: the solitary wave system induces significant positive pressures on the hull, while the primary wave system leads to remarkable negative pressures; both result in pronounced attitude variations of the moored ship, but the hydrodynamic forces and moments affected by the primary wave system are more pronounced.

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Francis, Ardath, and Suzanne I. Warwick. "The Biology of Invasive Alien Plants in Canada. 8. Lepidium latifolium L." Canadian Journal of Plant Science 87, no. 3 (July 1, 2007): 639–58. http://dx.doi.org/10.4141/cjps06044.

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The cruciferous weed Lepidium latifolium, perennial pepper-grass, is a relatively recent immigrant with a disjunct distribution in North America. Although first reported in the 1930s in Quebec and 1940s in Alberta, L. latifolium only started to attract attention as an invasive weed when it began to spread rapidly in the western parts of its US range in the 1980s, reaching British Columbia in the 1990s. Lepidium latifolium is a perennial weed of coastal wetlands, inland waterways, irrigation ditches, rangeland, hay meadows and waste areas, and tolerates saline/alkaline environments. Prolific seed production, rapid and substantial vegetative growth, creeping rhizomes with high storage capacity, potential for bud production at each node, and deep rhizome penetration have contributed to the widespread establishment of L. latifolium. Canopy height and density, combined with an accumulation of dead stalks in wetlands, has interfered with the regeneration of native plants and the habitats of birds and other animals, as well as hampering control of mosquitoes. In rangelands and pastures, L. latifolium can compete with native species and reduce forage quality. Lepidium latifolium has recently invaded agricultural crops such as cereal grains and alfalfa, and can contaminate hay shipments. Decaying litter may increase sodium content in surface soil, with a potential negative impact on salt-intolerant species. Lepidium latifolium has few natural enemies in North America. It has been partially controlled by flooding, intensive grazing, mowing and herbicides, but herbicides are of restricted use along waterways and in areas with native vegetation. Potential biological controls have shown little promise to date. Key words: Lepidium latifolium, perennial pepper-grass, perennial pepperweed, lépidie à feuilles larges, LEPLA, weed biology, invasive alien

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Baric, Mate, Robert Mohovic, Djani Mohovic, and Vinko Pavic. "The Simulation of Sloped Bank Effect Influence on Container Ship Trajectory." Journal of Marine Science and Engineering 9, no. 11 (November 18, 2021): 1283. http://dx.doi.org/10.3390/jmse9111283.

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The latest container vessel grounding in the Suez Canal, which occurred on 23 March 2021 (the Ever Given), raised many questions regarding the safety of navigation. The sudden concern about safety is due to fears that traffic flow through the Suez Canal could be blocked for longer periods of time. Besides external forces imposed by wind, in this case bank effect had a significant influence on the ship’s grounding. Bank effect occurs due to restricted water flow caused by narrow waterways. Many fairway design standards consider sloped banks such as those of the Suez Canal as unsubstantial in bank-effect forces. This paper analyses the impact of sloped banks on container ship trajectory and proposes minimal distances that may decrease bank-effect forces in order to reduce the risk of vessel grounding and increase the safety of navigation. However, this type of accident has happened before and may occur again due to a small sailing distance from the bank in cases where vessel speed is increased.

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38

Lee, Chun-Ki. "A Study about the interactions of vessels running parallely in proximity to one another and safe conducting of them in restricted waterways." Journal of Korean navigation and port research 29, no. 8 (October 1, 2005): 647–52. http://dx.doi.org/10.5394/kinpr.2005.29.8.647.

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39

Nguyen, Anh The, Tang Van Duong, L. Lee Grismer, and Nikolay A. Poyarkov. "A new granite cave-dwelling Bent-toed Gecko from Vietnam of the Cyrtodactylus irregularis group (Squamata; Gekkonidae) and a discussion on cave ecomorphology." Vertebrate Zoology 71 (March 17, 2021): 155–74. http://dx.doi.org/10.3897/vz.71.e60225.

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An integrative analysis of genetic, morphological, and ecological data recovered a new granite cave-adapted species, Cyrtodactylus raglaisp. nov., from the Song Giang River Valley, Khanh Hoa Province, Vietnam. Cyrtodactylus raglaisp. nov. is nested within one of two major clades within the irregularis species group where it forms a monophyletic group with C. cryptus and its sister species C. kingsadai. It differs from its sister species by an uncorrected pairwise sequence divergence of 16.5% and 16.8% based on the mitochondrial genes NADH dehydrogenase subunit 2 and its flanking tRNAs and the first subunit of cytochrome oxidase c (CO1), respectively. Cyrtodactylus raglaisp. nov. is a narrow-range endemic restricted to a riparian, granite cave microhabitat and its overall morphology bears that of other granite cave-dwelling ecomorphs in the genus. The Song Giang River Valley and its associated waterways are currently threatened by the construction of a hydropower station which will negatively impact the surrounding ecosystem. Urgent field surveys in this region are necessary in order to obtain critical data on its biodiversity and importance to conservation efforts in southern Vietnam.

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40

Stearn, Colin W. "Stromatoporoids from the Devonian (Eifelian to Lowest Frasnian) of Manitoba, Canada." Journal of Paleontology 70, no. 2 (March 1996): 196–217. http://dx.doi.org/10.1017/s0022336000023295.

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Twenty-two taxa of stromatoporoids are described from the outcrop belt of the Elm Point, Winnipegosis, Dawson Bay, and Souris River Formations in Manitoba. The Elm Point Formation contains a fauna of stromatoporellids of Eifelian age that is characterized by the new species, Stromatoporella manitobaensis. The Winnipegosis stromatoporoids are dolomitized but the widespread species Actinostroma tyrrelli, Taleastroma logansportense and the new species Trupetostroma imbrex can be recognized in this Givetian assemblage. The Dawson Bay fauna is characterized by the appearance of the dendroid forms, Stachyodes and Dendrostroma and species of Hermatostroma, Trupetostroma, and Parallelopora. A species of Actinostroma, comparable to A. filitextum is the most abundant stromatoporoid in the Dawson Bay Formation. The Souris River fauna, referred to as the Arctostroma contextum assemblage, is widespread at the Givetian-Frasnian boundary. Elements occur elsewhere in western Canada in the Beaverhill Lake, Waterways, lower Duperow and lower Fairholme units. Stromatoporoids in these four assemblages are relatively restricted in their stratigraphic occurrence and sufficiently widespread in their distribution to be useful in correlation.

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Altarriba, Elias, Sirpa Rahiala, and Taru Tanhuanpää. "Open-loop Scrubbers and Restricted Waterways: A Case Study Investigation of Travemünde Port and Increased Sulphur Emissions Immediately After the Scrubbers are Turned Off." TransNav, the International Journal on Marine Navigation and Safety of Sea Transportation 17, no. 2 (2023): 465–71. http://dx.doi.org/10.12716/1001.17.02.24.

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42

Ivory, Sarah J., Anne-Marie Lézine, Annie Vincens, and Andrew S. Cohen. "Effect of aridity and rainfall seasonality on vegetation in the southern tropics of East Africa during the Pleistocene/Holocene transition." Quaternary Research 77, no. 1 (January 2012): 77–86. http://dx.doi.org/10.1016/j.yqres.2011.11.005.

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Fossil pollen analyses from northern Lake Malawi, southeast Africa, provide a high-resolution record of vegetation change during the Pleistocene/Holocene transition (~ 18–9 ka). Recent studies of local vegetation from lowland sites have reported contrasting rainfall signals during the Younger Dryas (YD). The Lake Malawi record tracks regional vegetation changes and allows comparison with other tropical African records identifying vegetation opening and local forest maintenance during the YD. Our record shows a gradual decline of afromontane vegetation at 18 ka. Around 14.5 ka, tropical seasonal forest and Zambezian miombo woodland became established. At ~ 13 ka, drier, more open formations gradually became prevalent. Although tropical seasonal forest taxa were still present in the watershed during the YD, this drought-intolerant forest type was likely restricted to areas of favorable edaphic conditions along permanent waterways. The establishment of drought-tolerant vegetation followed the reinforcement of southeasterly tradewinds resulting in a more pronounced dry winter season after ~ 11.8 ka. The onset of the driest, most open vegetation type was coincident with a lake low stand at the beginning of the Holocene. This study demonstrates the importance of global climate forcing and local geomorphological conditions in controlling vegetation distribution.

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Mazhar, Sarah, Guangmin Sun, Anas Bilal, Bilal Hassan, Yu Li, Junjie Zhang, Yinyi Lin, Ali Khan, Ramsha Ahmed, and Taimur Hassan. "AUnet: A Deep Learning Framework for Surface Water Channel Mapping Using Large-Coverage Remote Sensing Images and Sparse Scribble Annotations from OSM Data." Remote Sensing 14, no. 14 (July 8, 2022): 3283. http://dx.doi.org/10.3390/rs14143283.

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Water is a vital component of life that exists in a variety of forms, including oceans, rivers, ponds, streams, and canals. The automated methods for detecting, segmenting, and mapping surface water have improved significantly with the advancements in satellite imagery and remote sensing. Many strategies and techniques to segment water resources have been presented in the past. However, due to the variant width and complex appearance, the segmentation of the water channel remains challenging. Moreover, traditional supervised deep learning frameworks have been restricted by the scarcity of water channel datasets that include precise water annotations. With this in mind, this research presents the following three main contributions. Firstly, we curated a new dataset for water channel mapping in the Pakistani region. Instead of employing pixel-level water channel annotations, we used a weakly trained method to extract water channels from VHR pictures, relying only on OpenStreetMap (OSM) waterways to create sparse scribbling annotations. Secondly, we benchmarked the dataset on state-of-the-art semantic segmentation frameworks. We also proposed AUnet, an atrous convolution inspired deep learning network for precise water channel segmentation. The experimental results demonstrate the superior performance of the proposed AUnet model for segmenting using weakly supervised labels, where it achieved a mean intersection over union score of 0.8791 and outperformed state-of-the-art approaches by 5.90% for the extraction of water channels.

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Price, Melissa R., Carl Person, and William K. Hayes. "Geographic variation and genetic structure in the Bahama Oriole (Icterus northropi), a critically endangered synanthropic species." PeerJ 3 (November 26, 2015): e1421. http://dx.doi.org/10.7717/peerj.1421.

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Bird species may exhibit unexpected population structuring over small distances, with gene flow restricted by geographic features such as water or mountains. The Bahama Oriole (Icterus northropi) is a critically endangered, synanthropic island endemic with a declining population of fewer than 300 individuals. It now remains only on Andros Island (The Bahamas), which is riddled with waterways that past studies assumed did not hinder gene flow. We examined 1,858 base pairs of mitochondrial DNA sequenced from four gene regions in 14 birds (roughly 5% of the remaining population) found on the largest land masses of Andros Island (North Andros and Mangrove Cay/South Andros). We sought to discern genetic structuring between the remaining subpopulations and its relationship to current conservation concerns. Four unique haplotypes were identified, with only one shared between the two subpopulations. Nucleotide and haplotype diversity were higher for the North Andros subpopulation than for the Mangrove Cay/South Andros subpopulation. Analysis of molecular variance (AMOVA) yielded a Wright’s fixation index (Fst) of 0.60 (PFst= 0.016), with 40.2% of the molecular variation explained by within-population differences and 59.8% by among-population differences. Based on the mitochondrial regions examined in this study, we suggest the extant subpopulations of Bahama Oriole exhibit significant population structuring over short distances, consistent with some other non-migratory tropical songbird species.

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Hasan, S. M. Rashidul, and Md Mashud Karim. "Proposed Inland Oil Tanker Design in Bangladesh Focusing CO2 Emission Reduction Based on Revised EEDI Parameters." Journal of Marine Science and Engineering 8, no. 9 (August 26, 2020): 658. http://dx.doi.org/10.3390/jmse8090658.

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Though inland ships account for a small portion of the total global CO2 emissions from shipping, from the individual country’s economic and environmental perspective, this is very important. To reduce CO2 emissions from sea-going ships by increasing energy efficiency, the International Maritime Organization (IMO) adopted a generalized Energy Efficiency Design Index (EEDI) in 2011. However, due to the variation in environmental, geographic and economic conditions, a generalized EEDI cannot be established in a similar fashion to that established by IMO. Shallow and restricted water effects, different fuel qualities (to reduce operational cost), increase in engine power requirements, reduction in carrying capacity, cargo availability, etc. make the EEDI by IMO inadequate for inland waterways. Therefore, an EEDI formulation based on revised parameters has been proposed for the inland ships in Bangladesh. This paper focuses on the possibility of CO2 emissions reduction from inland oil tankers in Bangladesh by implementing the revised EEDI formulation (henceforth denoted as EEDIINLAND). A sensitivity analysis was performed for the different ship design parameters of those oil tankers. Based on the analysis, suggestions were made on how to design inland oil tankers in Bangladesh using the revised EEDI formulation for reducing CO2 from the current level without any major cost involvement. Keeping the same speed and capacity, the vessels were redesigned based on those suggestions. The Computational Fluid Dynamics (CFD) analysis of those redesigned vessels using ‘Shipflow’ showed a reduction in CO2 emissions through increasing EEDIINLAND by 7.54–13.65%.

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46

Crerar, Lorelei D., Andrew P. Crerar, Daryl P. Domning, and E. C. M. Parsons. "Rewriting the history of an extinction—was a population of Steller's sea cows ( Hydrodamalis gigas ) at St Lawrence Island also driven to extinction?" Biology Letters 10, no. 11 (November 2014): 20140878. http://dx.doi.org/10.1098/rsbl.2014.0878.

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The Kommandorskiye Islands population of Steller's sea cow ( Hydrodamalis gigas ) was extirpated ca 1768 CE. Until now, Steller's sea cow was thought to be restricted in historic times to Bering and Copper Islands, Russia, with other records in the last millennium from the western Aleutian Islands. However, Steller's sea cow bone has been obtained by the authors from St Lawrence Island, Alaska, which is significantly further north. Bone identity was verified using analysis of mitochondrial DNA. The nitrogen-15 (δ 15 N)/carbon-13 (δ 13 C) values for bone samples from St Lawrence Island were significantly ( p ≤ 0.05) different from Bering Island samples, indicating a second population. Bone samples were dated to between 1030 and 1150 BP (approx. 800–920 CE). The samples date from close to the beginning of the mediaeval warm period, which could indicate that the population at St Lawrence Island was driven to extinction by climate change. A warming of the climate in the area may have changed the availability of kelp; alternatively or in addition, the animals may have been driven to extinction by the expansion of the Inuit from the Bering Strait region, possibly due to opening waterways, maybe following bowhead whales ( Balaena mysticetus ), or searching for iron and copper. This study provides evidence for a previously unknown population of sea cows in the North Pacific within the past 1000 years and a second Steller's sea cow extirpation event in recent history.

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Belamarić, Goran, Željko Kurtela, and Rino Bošnjak. "Simulation Method - Based Oil Spill Pollution Risk Analysis for the Port of Šibenik." Transactions on Maritime Science 5, no. 2 (October 21, 2016): 141–54. http://dx.doi.org/10.7225/toms.v05.n02.005.

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Statistical data, analyses and assessment of maritimepassenger traffic in sea ports in the Republic of Croatia pertaining to the traffic in the Port of Šibenik indicate that, following the expansion and reconstruction of berths for large ships in 2014, marine traffic in the waters of the Port of Šibenik and the Channel of St. Ante has been on the rise. There is therefore a need for pollution risk analysis for the Port of Šibenik. Risk assessment was made using the qualitative method of “Risk assessment-based threat ranking”, following which a scenario involving discharge of harmful substances (oil spill) and possible pollution of the Port of Šibenik and the Channel of St. Ante in difficult navigating conditions in restricted waterways and bad weather was simulated. Marine pollution itself has no direct impact on human life. There are usually no human casualties, although major disasters can affect human health. There can therefore be dire indirect consequences, with negative impact on the eco-system, and consequently on some of the most important branches of industry like tourism, sports, fishing, etc. The prevalent northerly and southerly winds have a particularly high influence on the spreading of oil spills in closedoff waters like those of the Port of Šibenik. The influence of sea currents in the Krka river basin and the Channel of St. Ante is exceptionally strong, especially during heavy rains accompanied by increased water flow. Oil spill simulation is therefore an important tool for planning preventive action and response operations in case of oil spill from ships.

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48

Kim, Chang-Je. "Wave Field Near a Vessel in Restricted Waterway." Journal of Navigation and Port Research 35, no. 7 (September 30, 2011): 557–62. http://dx.doi.org/10.5394/kinpr.2011.35.7.557.

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Macdonald, Elena, Noelia Otero, and Tim Butler. "A comparison of long-term trends in observations and emission inventories of NO<sub><i>x</i></sub>." Atmospheric Chemistry and Physics 21, no. 5 (March 17, 2021): 4007–23. http://dx.doi.org/10.5194/acp-21-4007-2021.

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Abstract. Air pollution is a pressing issue that is associated with adverse effects on human health, ecosystems, and climate. Despite many years of effort to improve air quality, nitrogen dioxide (NO2) limit values are still regularly exceeded in Europe, particularly in cities and along streets. This study explores how concentrations of nitrogen oxides (NOx = NO + NO2) in European urban areas have changed over the last decades and how this relates to changes in emissions. To do so, the incremental approach was used, comparing urban increments (i.e. urban background minus rural concentrations) to total emissions, and roadside increments (i.e. urban roadside concentrations minus urban background concentrations) to traffic emissions. In total, nine European cities were assessed. The study revealed that potentially confounding factors like the impact of urban pollution at rural monitoring sites through atmospheric transport are generally negligible for NOx. The approach proves therefore particularly useful for this pollutant. The estimated urban increments all showed downward trends, and for the majority of the cities the trends aligned well with the total emissions. However, it was found that factors like a very densely populated surrounding or local emission sources in the rural area such as shipping traffic on inland waterways restrict the application of the approach for some cities. The roadside increments showed an overall very diverse picture in their absolute values and trends and also in their relation to traffic emissions. This variability and the discrepancies between roadside increments and emissions could be attributed to a combination of local influencing factors at the street level and different aspects introducing inaccuracies to the trends of the emission inventories used, including deficient emission factors. Applying the incremental approach was evaluated as useful for long-term pan-European studies, but at the same time it was found to be restricted to certain regions and cities due to data availability issues. The results also highlight that using emission inventories for the prediction of future health impacts and compliance with limit values needs to consider the distinct variability in the concentrations not only across but also within cities.

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Varyani, K. S., B. Hamoudi, and R. McGregor. "Interactive Forces Between Three Ships in a Restricted Waterway." IFAC Proceedings Volumes 30, no. 22 (September 1997): 151–57. http://dx.doi.org/10.1016/s1474-6670(17)46506-2.

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Journal articles on the topic 'Restricted waterways'

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