ADCP's Application to Ocean Current Measurement in Dapa Port

1. Where is Dapa Port?

Dapa Port is located in the municipality of Dapa in Surigao del Norte, Philippines.

Port Scale and Throughput

The port is considerably large, with important transportation nodes within the region. It has a considerable throughput that includes all types of goods, from minerals to agricultural products and manufactured goods. The infrastructure in this port is designed for both domestic and international shipments. For many years, the port expansion has been carried out for large vessels and also trade volumes.

Routes and Business

Dapa Port is well-connected to other domestic and international ports. Domestically, it is a very important link in moving goods from one island or region of the Philippines to another. At the international level, it has trade relations with neighboring Asian countries. The major businesses include loading and unloading of cargo, storing in well-equipped warehouses, and value-added services like packaging and sorting. The port has also played a major role in the economy of the local people by exporting its local products and importing what is necessary for them.

Port Management and Operation

The port is managed by a professional team of port authorities. They are responsible for ensuring efficient vessel traffic management, including berthing and departure schedules. Regular maintenance and upgrades of port facilities are carried out to enhance safety and operational efficiency. They also coordinate with customs, immigration, and other regulatory agencies to ensure smooth flow of goods and compliance with relevant laws and regulations.

Port Facilities

Dapa Port has modern berths and is capable of handling vessels of various sizes, from the smallest fishing boats up to big cargo vessels. Large areas are available for different types of cargoes: temperature-controlled warehouses storing perishable goods. The port is also equipped with machinery at the highest level, able to load and unload goods efficiently, such as cranes and conveyor belts. Furthermore, services related to refueling, water supply, and even ship repair are available in an instant.

Channel and Direct Shipping

The port has a properly dredged channel that is in good condition to facilitate the safe entry and exit of ships. The channel is deep enough and wide enough to accommodate large-scale vessels. There are direct shipping lines to major ports in the Philippines and to some international destinations that significantly reduce transportation time and cost, hence promoting trade and economic development.

2. Why is it necessary for us to measure the current at Dapa Port?

We have to measure currents from Dapa Port significantly regarding its operational and management issues. Because, for ship safety, accurate data helps in guiding ships for berth and departure. The direction and speed of the currents might affect the ship's maneuverability; thus, being informed of these, it could decrease the danger of a collision with the port structures or other vessels. In cases of adverse weather or a big cargo ship, this will become very critical.

The information on ocean currents now becomes very vital in optimizing the schedules for loading and unloading during port operations. Various current conditions may affect the time and efficiency of such operations. For example, strong currents may require extra mooring arrangements or adjustments in handling procedures to ensure safety for the workers and the cargo.

Thirdly, in regard to long-term port development such as expansion and infrastructural development, knowledge about the flow of currents would be fundamentally important. In any event, forces generated from those currents against any given structure in the facility could damage its stability and strength. If current data were available, engineers could design stronger, efficient port facilities that would easily withstand tides of the water.

More informally, Acoustic Doppler Current Profiler (ADCP) represents a much handier way of measuring ocean currents compared to traditional techniques. Besides, it can easily, accurately, and promptly get current information with depth details, thus real-time data, considered fundamental for the smooth operation of Dapa Port.

3. How do ADCPs using the Doppler principle work?

The Doppler principle is the principle behind the operation of ADCPs. ADCPs transmit acoustic signals into the water. These acoustic waves immediately interact with suspended particles or other objects in the water moving with the ocean current. As the waves are reflected back to the ADCP meter, their frequency changes due to the Doppler effect.

With this Doppler shift analysis, the ADCP current meter calculates the velocity of the ocean current at different depths.

ADCP in Port Ocean Current Measurement

Shipborne ADCP

Shipborne ADCPs are deployed on ships operating within the area of Dapa Port. While the ship moves within the port area, the ADCP current profiler continuously sends acoustic signals in different directions. It can provide ocean current measurements at a number of points along the ship path and thus give a synoptic view of the distribution of the current in the area covered by the movement of the ship.

Fixed ADCP

Fixed ADCPs are positioned at a fixed location in the port, such as on the seabed near key installations or at a point critical to the channel. In this way, they make continuous measurements of the conditions of the ocean current at that spot over a long period of time. This therefore forms useful data on the pattern commonly occurring in the current, its impact, and hence at that particular fixed point in the port facility.

4. What is required for high-quality measurement of Dapa port currents?

The equipment to be used for high-quality measurement of ocean currents in Dapa Port should possess certain characteristics. First, the material of the equipment should be of a reliable type. It should be able to bear up to the harsh marine environment: corrosion by seawater, pressure changes, and impacts from waves. The casings of ADCPs may be made from materials like titanium alloy. It has a high strength and very good corrosion resistance; thus, it can serve in the marine environment for long periods.

The equipment should be small in size, light in weight, and of low power consumption. The small size allows for its installation in various parts of the port, whether aboard ships or fixed on the ground. Light weight helps in handling and deployment while low power consumption ensures that equipment can operate continuously without frequent replacement of batteries or excessive power supply.

Thirdly, cost-effectiveness is important for large-scale measurement. The equipment should have a reasonable cost so that it can be widely used in the port to obtain comprehensive current data.

5. How to Choose the right equipment for current measurement?

According to the Usage Purpose

Shipborne ADCP: The shipborne ADCP will be relevant in conducting mobile measurements while the ship navigates in the port area in case the rapid acquisition of general information in large parts of the port needs to be envisaged, thus the advantage that will ensue for wide coverage while the vessel is on its movement.

Bottom-mounted ADCP: When long-term and fixed-point monitoring of the ocean current at some place in the port is called for, such as near very important facilities or areas where it is required to keep very close eyes on the characteristics of the current, bottom-mounted ADCP would be more appropriate; it gives steady and sustained data from a fixed position.

Buoy-mounted ADCP: In places where the installation of fixed equipment on the seabed or on other structures is not convenient, buoy-mounted ADCP can be installed. The buoy-mounted ADCP will measure the ocean current in the upper layers of the water body and transmit the same wirelessly.

According to Different Frequencies

Water depths in Dapa Port are within 70m, where usually a choice of 600kHz ADCP can provide fairly good current data.

When the water depth reaches up to 110m, then 300kHz ADCP can be more appropriate since at this depth, capturing current characteristics is better.

Only for deeper water areas with water depth up to 1000m should 75kHz ADCP be selected, being able to reach deeper water and pick up reliable current information.

There are well-known ADCP brands such as Teledyne RDI, Nortek, and Sontek. However, a Chinese ADCP brand, China Sonar PandaADCP, is also worth considering. It is made of all - titanium alloy materials and offers an excellent cost-performance ratio. You can learn more about it at (https://china-sonar.com/).

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