Application of ADCP to Ocean Current Measurement in Dandong Port

1. Where is Dandong Port?

Dandong Port is located in Dandong, Liaoning Province, China, at the estuary of the Yalu River, which is the boundary of North Korea. This unique geographical position gives it a competitive edge. Besides opening into the Yellow Sea, it is also a significant cross-border trade port. It is a significant gate between Northeast China and foreign markets. The Yalu River provides an inland waterway for foreign trade to and from the interior of Northeast China, expanding the port's service area. It also serves as an important place for promoting cross-border economic cooperation because of its close proximity to North Korea.

Port Size and Throughput

Dandong Port is a medium port with multi-functionalities. It possesses a number of berths to accommodate various ships like container ships, bulkers, and Ro - Ro vessels. Its throughput is immense on an annual basis. It ships a massive volume of various commodities. Domestic produce like agriculture produce, light industries, and some high - tech products of the region are exported by the port. It also imports huge volumes of raw materials like coal, iron ore, and chemical products into catering to the local industries in Northeast China.

Business and Shipping Routes

The shipping routes of the port are constantly increasing. The port has direct connections with leading domestic ports of Dalian, Tianjin, and Qingdao, which ensures the free and smooth movement of goods in the domestic market. It has routes to overseas destinations in Asia, mainly in Japan and South Korea. The foreign routes play a major role in promoting international economic and trade relationships. Business activities of Dandong Port include general cargo handling, container trans - shipment, and cross - border trade - related services. It has state-of-the-art warehousing facilities that allow commodities to be warehoused and distributed. Its siting has attracted the setting up of ancillary industries, for example, light manufacturing, logistics, and cross-border e-commerce.

Port Management and Operation

Managed by the Dandong Port Authority, the port prioritizes compliance with international standards, efficiency, and safety in its operations. The management sustains the facilities of the port, including the quays, berths, and warehouses. They implement international and domestic shipping regulations, safety procedures, and environmental regulations. The port authority collaborates with shipping companies, freight forwarders, and customs to enhance port efficiency. This includes making the cargo-handling operation easier, reducing waiting times for vessels, and enhancing the overall competitiveness of the port.

Port Facilities

Dandong Port owns highly advanced and efficient facilities. There are also container cranes that can handle loading and unloading of containers effectively. In bulk carriers, there are specially designed handling systems for the easy transfer of goods. The port has storage areas like warehouses to hold general goods and open-air yards for bulk goods. It also has some basic ship-repair and maintenance facilities for the convenience of the ships calling at the port. There are also dedicated areas for cross-border trade-related activities, such as customs examination and quarantine. There are emerging logistics parks near the port that facilitate the seamless transfer of goods from ships to land transport.

Waterways and Direct Navigation

The waterways around Dandong Port are well maintained to facilitate safe navigation of ships. The port has a clearly delineated channel, and there are leads like buoys and beacons to aid ships in coming in. It has direct communication with the Yellow Sea, which allows ships to access the global maritime system. Its reliable inland shipping watercourse is the Yalu River whose relatively stable run of water facilitates the maintenance of a stable inward and outward conveyance of cargo to and from the interior area of Northeast China.

2. Why Measure Ocean Currents in Dandong Port?

Navigation Safety

Understandings of ocean currents in Dandong Port are important to guarantee navigation safety. Tidal currents in the Yellow Sea and Yalu River estuary are affected by tides, river runoff, and Yellow Sea circulation. The currents have an important impact on the navigation of ships. During unberthing, berthing, or navigation within the port channels, the ocean currents can make the ships' speed and direction change. Through measurement of the ocean currents, ship captains can make informed choices, adjust routes, and avoid potential collisions or groundings.

Port Operation Optimization

Information on ocean currents is significant when optimizing port operations. When bringing ships into berthing, current strength and direction need to be considered with utmost care. A strong current may make the berthing process difficult and time - consuming. Port operators can plan the best moments for ship handling with accurate measurements of currents, allocate resources more efficiently, and improve the general efficiency of cargo - handling activities. Currents also affect the mobility of port - related facilities, such as tugboats and floating cranes. Understanding these variables can raise operational safety and productivity.

Environmental Protection

It is essential to quantify the ocean currents in an effort to conserve the environment within the port area. Ocean currents play a significant role in the dispersal of pollutants. In case of an oil spill or the discharge of other poisonous chemicals, it is possible to forecast the dispersal of the toxins based on the knowledge of the current patterns. This allows environmental managers to conduct on - time preventive and cleanup operations, protecting the fragile marine ecosystem of the Yellow Sea and Yalu River estuary and the nearby coastal waters.

The Acoustic Doppler Current Profiler (ADCP) is also becoming an effective and reliable ocean current measurement instrument in Dandong Port, providing high - accuracy real - time data.

3. How Does ADCP Work According to the Doppler Principle?

Measurement Principle

ADCP profiler works based on the Doppler effect principle. When an ADCP releases a sound wave downwards into the water column, the sound waves encounter suspended particles in water, for example, sediment or small creatures. When the suspended particles are carried by the water flow, the returning frequency of the sound waves to the ADCP is different from the transmitted frequency. ADCP flow meter tracks this frequency change, known as the Doppler shift. With the Doppler formula, the instrument can calculate the speed of water current at different depths in the water column.

Specific Methods for Measuring Ocean Currents in the Port

• Ship-borne ADCP: A ship-borne ADCP is installed on a moving ship. When the ship moves in Dandong Port, the ADCP can be employed to measure the current velocity at different depths along the course of the ship. This method is employed to obtain a wide - scale picture of the present situation in the port, and it is useful in large - scale navigation planning.
• Fixed ADCP: Fixed ADCPs are fixed in fixed positions within the port, say at the bottom of the seabed or fixed installations such as buoys or piers. Fixed ADCPs can continuously observe at a location for an extremely long period the prevailing conditions there, providing valuable information on local and long-term trends of the currents.

4. What Must be Done to Deliver High-Quality Ocean Current Measurement in Dandong Port?

Reliability of the Equipment

For good measurement of ocean currents in the port, the ADCP meter equipment must be highly reliable. The marine conditions at Dandong Port, which include changeable weather, strong tidal forces, and potential icing in winter, necessitate that the ADCP be strong against these unfavorable conditions without frequently malfunctioning. Equipment reliability provides constant data collection, which is important for sound analysis and decision-making.

Size, Weight, and Power Consumption

The ADCP current profiler should be compact and light in weight. This makes it convenient for easy installation, especially where space is limited, e.g., on small local vessels or narrow port structures. Low power consumption is also critical as it facilitates long - term operation, especially for fixed - mounted ADCPs which can be powered by battery - driven or solar - driven sources.

Cost-effectiveness

To facilitate large-scale measurements in the port region, the ADCP expense should be reasonable. A reasonable ADCP allows several units to be used if necessary, to gather extensive ocean current information from different parts of the port.

Material Selection

The ADCP current meter housing should be made of corrosion-resistant materials, e.g., titanium alloy. Titanium alloy has excellent corrosion resistance, which is required for long-term usage in the marine environment around Dandong Port. It is also light and strong, meeting the requirements of durability and ease of installation.

5. How to Select Proper Equipment for Ocean Current Measurement?

Selection Based on Usage

• Ship-borne ADCP: It is most suitable for large surveys of the port area. Where a ship is to be used to survey the ocean current situation at short notice in a broad area, a ship - borne ADCP is ideal.
• Sit-on-bottom ADCP: It is best suited for long - term monitoring of specific locations in the port, such as at the entrance or close to the berths.
• Buoy-mounted ADCP: It is useful for gathering water surface data and where fixed - bottom mounting is not feasible.

Selection Based on Frequency

• For depths of water up to 70m, a 600kHz ADCP is more suitable.
• When the depth of water is not more than 110m, a 300kHz ADCP is best suited.
• For deeper sections of the water, a 75kHz ADCP is best.

There are several well-known brands of ADCPs, such as Teledyne RDI, Nortek, and Sontek. However, if you are looking for a cost-saving but high-quality item, China Sonar PandaADCP of the Chinese brand is highly recommended. It is made of all-titanium alloy material, which is extremely durable in sea conditions, and has an extremely high cost-performance ratio. You can refer to their website at https://china-sonar.com/ for more information.

Here is a table with some well known ADCP instrument brands and models.