Most significant ports worldwide have, at one time or another, undertaken extra dredging efforts, commonly known as capital dredging. This process is carried out to extend and deepen access channels, establish turning basins, and achieve the desired water depths within their marina facilities.
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Dredging is crucial to preserving navigable waterways, access to ports, and other critical infrastructure. It is also fundamental for global trade and development in an interconnected world.
Dredging Challenges in Ports and Harbors
One of the main problems affecting port management and operations is sediment contamination. For many years, dredging has been the solution to these problems. To maintain navigable depth, the material is removed during dredging and deposited beyond the port or harbor.
Due to the ongoing movement and redeposition of material within the coastal system, this operation must be done often. However, dredging has a significant negative impact on the environment and the financial system.
The dredging sector is at a turning point. Numerous inland marine ports need extensive long-term renovations due to their poor condition. Like the Panama Canal, several East Coast ports must expand their channels to accommodate 50-foot ships while unloading and loading commodities.1 However, challenges still exist.
Dredging must be a fundamental component of any infrastructure design to guarantee that ports and harbors can appropriately fulfill these expanding global trade needs.
Impact on Global Trade
The dredging sector is significantly influenced by seaborne transactions, which are the foundation of international trade and the global economy. Before 2020, almost 80% of global commerce by volume and more than 70% of global trade by value were transported by water and managed by ports all over the globe.2
Dredging has a significant influence on our way of life. It keeps the waterways in our country passable, critical for global commerce, and preserves ports deep enough for huge ships by eliminating accumulated sediments, promoting international trade.
Dredging development is primarily due to the necessity to offer high-value, profit-generating services to compensate for the low-margin ocean freight and increase global trade transactions.
Modern logistics is primarily recognized as a critical aspect and a catalyst for economic progress. Consequently, there are several outcomes between the logistics business and regional economic growth.
Innovative Dredging Technologies
Remedial dredging is an eco-friendly dredging system. The lowest possible turbidity is the goal of remedial dredging procedures to get a high concentration of dredged silt. The accuracy with which remedial dredging activities are carried out is crucial. These are often modified versions of grabs, backhoes, and cutter suction hopper dredgers.3
Precision dredging entails correctly removing the thinnest layers feasible to dredge the least amount of contaminated material available. As a result, the lowest quantity of material will be required for treatment or disposal.
The most recent innovation is the autonomous dredger. The autonomous system is flexible and easily adaptable to align with the individual needs of the user. In addition, a human-machine interface is now being developed, enabling further evaluation and improvement of the user interaction when used with the simulator.4
Adaptive Dredging Strategies
Modelling plays a crucial role in the identification of risks and the optimization of dredging methods. It enables the construction of efficient models that can be rapidly developed and refined promptly to address specific questions that arise during project planning.
Hydrodynamic models, when executed effectively, have become the prevailing approach for planning activities related to aquatic dredging and maintenance (ADM). This is due to the intricate nature of estimating water flows, weather impacts, sediment dynamics, and ecological reactions.5
Sustainable Dredging and Environmental Compliance
Clients of maritime infrastructure projects are increasingly conscious of the importance of sustainability as a goal for their projects, and they base their cooperation in part, if not entirely, on contractors' willingness to operate in this manner.
Most dredging firms operate inside signatory nations, creating a regulatory framework that encourages enterprises to make CSR decisions targeted at minimizing environmental effects.
International Collaboration and Knowledge Sharing
Two Netherland dredging companies, Doggerland and Abeko succeeded in completing a significant dredging project in the United Kingdom. At the end of 2022, Doggerland was awarded a public tender to excavate a deeper canal leading to the Grimsby GRT port.6
This canal allows bigger ships to dock and unload even at low tides. Therefore, it was critical to dredge the channel and increase the operational efficiency of the Grimsby port.
Case Studies and Success Stories
The state of the spectral coupled model is used to analyze the port of Marano Lagunare (Italy). Closing a secondary port entry is often recommended to decrease sediment flow into the port.
Dredging the secondary port entrance completely improves water circulation or efficient renewal, improving oxygenation at the canal bottom. Keeping secondary entrances open in lagoon harbors rather than closing them, as in fluvial or marine ports, may be desirable to keep a high flow velocity. This system helps to keep the water and sediment quality higher.7
Dredging operations, particularly capital dredging, are vital for the efficient functioning of major ports and harbors worldwide. They are crucial in maintaining navigable waterways, ensuring access to ports, and supporting global trade and development. However, the practice has challenges, as it can have significant environmental and financial implications.
The dredging sector is transforming, with the need for infrastructure enhancements becoming increasingly evident. This is driven by expanding global trade demands and the need to accommodate larger vessels. Dredging must be a fundamental component of any infrastructure design to meet these evolving trade needs.
Innovative dredging technologies are emerging to make the process more environmentally friendly and efficient.
Remedial dredging aims to minimize turbidity and maximize the concentration of dredged material, while precision dredging involves removing the thinnest layers possible to reduce the amount of contaminated material requiring treatment or disposal. Additionally, the development of autonomous dredgers enhances adaptability to individual user needs.
It is evident that effective dredging practices are crucial for maintaining the functionality of ports and harbors while mitigating environmental impact and supporting the demands of global trade.
References and Further Reading
1Grieco, L. (2021). Panama Canal Expansion Celebrates Fifth Anniversary with Deeper Draught. [Online] Central Dredging Association. Available at: https://dredging.org/news/48/panama-canal-expansion-celebrates-fifth-anniversary-with-deeper-draught (Accessed on 16 October 2020).
2Cohen, M., et al. (2020). Dredging: The Facts. [Online] International Association of Dredging Companies. https://dredging.org/media/ceda/org/documents/resources/cedavarious/publications-dredging_the_facts.pdf (Accessed on 15 October 2020).
3Fan, Z., et al. (2019). Targeting Remediation Dredging by Ecological Risk Assessment of Heavy Metals in Lake Sediment: A Case Study of Shitang Lake, China. Sustainability. https://doi.org/10.3390/su11247251
4Royal IHC. (2023). Autonomous dredgers on the horizon. [Online] Royal IHC. Available at: https://www.royalihc.com/dredging/dredging-innovations/autonomous-dredgers-horizon (Accessed on 15 October 2020).
5Kettle, B., et al. (2018). White Paper on Adaptive Dredge Management. Report to United States Army Corps of Engineers, South Atlantic Division, Jacksonville District. https://www.researchgate.net/publication/331999325_White_Paper_on_Adaptive_Dredge_Management_-_draft_November_2018
6Hrvacevic, Z., et al. (2023). Doggerland and Abeko successfully complete major dredging project in the UK. [Online] Dredging Today. Available at: https://www.dredgingtoday.com/2023/09/01/doggerland-and-abeko-successfully-complete-major-dredging-project-in-the-uk/ (Accessed on 16 October 2020).
7Bosa, S., et al. (2020). Improvement in the Sediment Management of a Lagoon Harbor: The Case of Marano Lagunare, Italy. Water. https://doi.org/10.3390/w13213074