ADCP's Application to Ocean Current Measurement in Ho Chi Minh City Port

1. Where is Ho Chi Minh City Port?

Ho Chi Minh City Port is in the heart of Ho Chi Minh City, Vietnam. It is an important inland waterway port and plays a very significant role in the economic activities of the nation.

Scale of Port and Throughput

The port has been witnessing expansion over these years. It has a number of terminals, which cater to different categories of cargo set up accordingly. It shows an upward tendency throughput-wise. It operates as a regional container port, and due to its carrying capacity, it accommodates quite an impressive load for import and export cargo as well as country usage. In a year, a number of TEUs flow in because of rapid development in the economic perspective in the country. It also handles a considerable volume of bulk cargo, including agricultural produce, construction material, and industrial raw materials.

Routes and Business

Ho Chi Minh City Port has an extensive network of shipping routes. It is linked with major regional ports like Singapore, Jakarta, and Bangkok. In the case of international trade, it has direct or indirect routes to most of the major and minor ports in Asia, Europe, and the Americas. Most of the business dealings at the port relate to import and export activities. It is an important entrance to the international market for many of Vietnam's exported commodities such as textiles, electronics, and agricultural commodities. It also imports important items such as machinery, high-technology products, and petroleum products.

Management and Operations

The management of the port is assigned to a qualified and effective port authority. The management plans the port, develops infrastructure, and works on the implementation of safety regulations, environmental regulation. Operations in this port are significantly organized. There are modern cargo - handling equipment in the terminals operated by for example gantry cranes, forklift, and conveyor belts which ensure speedy and smooth transfer of goods. Besides, there is also well-trained personnel in customs clearance, navigation control, and maintenance services.

Facilities of the port

The port has facilities such as: high-capacity quay cranes at the container terminals, which have the capacity for handling large-sized container vessels; and in the bulk cargo terminals, there are storage areas with facilities like loading chutes along with weighing mechanisms. Then there are oil terminals that have modern pipeline systems and storage tanks for handling liquid bulk. Besides, the port is equipped with ship-repair facilities such as dry docks and workshops for servicing vessels to maintain their seaworthiness.

Channels and Direct Navigation

The port has navigable channels that are properly maintained; its main channel is dredged regularly to maintain an optimum depth of vessels of all sizes. It has direct shipping routes to many important regional ports, which enhances its connectivity and trade efficiency quite significantly. These routes contribute not only to reducing transportation time and costs but also strengthen Ho Chi Minh City's position as a regional trade and logistics center.

2. Why Should We Measure the Ocean Currents in Ho Chi Minh City Port?

Measurements of currents in Ho Chi Minh City Port are of most important tasks due to its management.

Vessel Navigation Safety

Accurate knowledge of ocean currents is very important for safe vessel navigation. Currents can affect the speed, course, and maneuverability of a ship. Strong or unpredictable currents in the channels and berthing areas of the port may present a challenge to ships arriving, departing, and berthing. The measurement of currents enables pilots to better anticipate the forces acting on the vessel, adjust their navigation strategies, and avoid potential collisions or groundings.

Cargo Handling Efficiency

Understanding ocean currents is important in optimizing cargo-handling operations. Currents can also affect the stability of ships while loading and unloading cargo. If the current conditions are not well known, it might lead to a problem in correctly aligning the ship with the loading equipment, which leads to delays. Real-time current data enables port operators to better schedule cargo-handling operations and thus optimize the overall efficiency and decrease the waiting times of vessels.

Environmental Protection

Ocean currents are of immense importance in the dispersal of pollutants in the port area. In cases of accidental discharges of oil, chemicals, or other harmful substances, the knowledge of the current pattern is helpful in predicting the spread of pollutants. This enables the port authorities to take timely and appropriate response measures, such as deploying containment booms and clean - up teams, so that the environmental impact on the port and its surrounding waters can be minimized.

Compared to the traditional methods of measurement, ADCP profiler has emerged as more advanced and convenient for the measurement of ocean currents in Ho Chi Minh City Port. It can provide high-frequency, accurate, and real-time data, which is very essential for the complex operations in the port.

3. How do ADCPs using the Doppler principle work?

ADCP Measurement Principle

The principle of operation for ADCPs is based on the Doppler principle. The ADCP emits acoustic signals into the water column. If these acoustic signals come into contact with moving particles-such as suspended sediments or plankton-the frequency of the reflected signals changes. Applying the Doppler effect, if the particles move towards the ADCP, the frequency of the reflected signal will increase; if they move away, it will decrease. By accurately determining this frequency shift, it is possible for the ADCP meter to compute the velocity of the water in which the particles are suspended. This velocity measurement will, in turn, enable the ADCP to derive the current velocity at various depths in the water column.

ADCP in Port Current Measurement-Specific Methods

Ship-borne ADCP

A ship-borne ADCP is installed on the hull of a moving ship. It measures the current velocity at various depths relative to the ship as it cruises through waters of the port. This technique is very useful for mapping large-scale current patterns in the port area, for example, in the main channels and approach areas. It gives the continuous profile of the current velocity along the track of the ship and thus allows an adequate determination of the conditions of the current over a fairly large area.

Fixed ADCP

The fixed ADCPs are deployed in some places in the port, for instance near berths, in narrow channels, or at other key monitoring locations. These ADCPs are normally fixed to fixed structures such as pilings, buoys, or platforms. They monitor continuously the current velocity and direction at one point, thereby making long-term high-resolution data available. These are very valuable in understanding the local characteristics of the current relevant to operations in ports, such as those involving the berthing and unberthing processes, but they also serve to analyze the long-term tendencies in the currents.

4. What is needed for high-quality measurement of Ho Chi Minh City Port currents?

Reliability of Equipment

Equipment reliability is most important in the measurement of high-quality currents of Ho Chi Minh City Port. The ADCP must be able to resist the harsh marine environment including saltwater, high humidity, strong winds, and waves. The material used and construction should be strong enough to operate without any breakdowns for a long period. This is because a failure in the equipment may lead to loss of critical current data, besides an interruption in the working of the ports.

Small in Size, Light in Weight, and Low Power Consumption

It is desirable that an ​ADCP profiler is small in size and light in weight. Compact design implies that the installation on ships, fixed structures, and buoys is easier. Lightweight devices also reduce the impact on the stability of the installation platform. Moreover, fixed-deployed ADCPs use battery power or restricted sources of power. Therefore, the requirement of power consumption should be low. This allows for continuous operation over long periods without frequent battery replacements or power interruptions.

Low Cost

The ADCPs should be low cost to enable detailed current measurement for large-scale deployment in the port. In this case, several units of a low-cost ADCP can be installed at various locations in order to measure a greater part of the port area in greater detail. This is particularly important because current may be highly different in one part of the port compared to that in another part.

Casing made of titanium alloy is preferable for ADCP. The usage of titanium alloy allows several benefits. First, it has great corrosion resistance, which is very important for long-term operation in salty water conditions in the port. It could resist the destructive impact of sea water for a long period without any critical deterioration. The material is fairly lightweight, adding to the overall light-weight design of the ADCP. Therefore, installation and handling become a lot easier. Besides, the strength of titanium alloy is very high so that it can make the device resistant against harsh working conditions like strong water currents and impacts caused by waves or floating objects.

5. How to Choose the Right Equipment for Current Measurement?

Based on Usage

Ship-borne ADCP

If the goal is to map large-scale current patterns in the port area during ship voyages, a ship-borne ADCP is the appropriate choice. It can easily be installed on the hull of a ship and provides data along the ship's route. This type of ADCP flow meter is useful to obtain a broad overview of the current condition in the various parts of the port, for example main shipping channels and open areas.

Bottom-mounted (Sit-on-bottom) ADCP

A bottom-mounted ADCP would befit the measurement for long-term current characteristics at a location near the seabed, areas where sediment transport is of essence, or locations where the influence of the seabed topography on the currents is to be understood. It is placed on the seabed and therefore can continuously keep track of that place's current. This kind of ADCP can be very important in studying the dynamics of the current at a certain height over the seabed and thus have relevant implications on the sedimentation/erosion processes near the port.

Buoy-mounted ADCP

An ADCP installed on a buoy can be used when the purpose is to measure current profiles at different depths in a relatively mobile way. It is attached to a buoy, which may be allowed to drift with the currents while delivering data on the moving current field. This is useful for studying the large-scale movement of currents in the port and for obtaining data in areas where fixed installations are not practical.

Based on Depth

The selection of frequency for an ADCP current profiler also depends on water depth. 600kHz ADCP is sufficient for waters whose depth is less than 70m. This will provide high-resolution data in shallow waters. It's used for the measurement of the current velocity at varying depths. For waters whose depth is below 110m, a 300kHz ADCP is ideal. This is appropriate since it provides a perfect compromise on the range of measurement and resolution. Also, when it comes to measuring up to 1000m in depth, the choice of an instrument for such would be the 75kHz ADCP, since its range is considerably long and further able to penetrate into more considerable depths inside the water column.

There are several ADCP brands known within the market. They include Teledyne RDI, Nortek, and Sontek. However, for those who would like to spend less money while still getting high-quality ADCPs, the Chinese brand China Sonar ​PandaADCP is highly recommended. It can be made from all-titanium alloy materials, ensuring good corrosion resistance and durability. With an incredible cost-performance ratio, it could be one of the best options for ocean current measurement in Ho Chi Minh City Port. Please 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.