ADCP's Application to Ocean Current Measurement in Borongan Port

1. Where is Borongan Port?

Borongan Port is located within the City of Borongan in Eastern Samar, a province in the Philippines.

Port Scale and Throughput

The port is of medium size. It serves as an important transportation facility in the local area, with large amounts of freight, like agricultural products, fishing gear, and consumer goods. The throughput reflects the local economic activities, which mainly consist of fishing and small-scale trading. The port is still developing to meet the growing needs of the local community and the wider surroundings.

Routes and Business

Shipping routes connect the port to various domestic ports. The main activity here involves the shipment of local produce to other areas and the import of such necessities. The port has a fishing base as the base for the fishing vessels, where the boats load their catch after landing it at the ports. The warehousing and handling of different kinds of cargos are also part of its ancillary services.

Port Management and Operation

The management of the port rests on the local port authorities. This is the governing body to run the day-to-day activities within the port facility. They maintain the order of the port, ensuring security for ships and personnel; thus, they coordinate the agencies concerned with customs and other regulatory procedures. Maintenance and improvements are regularly undertaken to keep the facilities of the port in continuous working condition.

Port Facilities

Borongan Port has berthing facilities for different sizes of fishing boats and small- to medium-sized cargo vessels. There are warehouses for goods, facilities for cold storage of perishable items like fish, and loading-unloading equipment to help in the transfer of goods. Basic services like the supply of fuel and water for the vessels are also provided.

Channel and Direct Shipping

One may see the quite well-maintained channel, allowing ships to be in and out of this port. The depth of a channel, as well as its width, is very closely followed and maintained throughout. But even without a large amount of direct international shipping en routes through it, it has many links through other domestic ports, putting no drag on the process inside the country.

2. Why is there a need to measure ocean currents in the Borongan Port?

Measuring the ocean current in Borongan Port is so important for its operation and management. In relation to the safety of the ships, for example, a good understanding of the ocean current patterns guides during berthing and departure. It can help avoid the collision of ships with port structures or other vessels, particularly during adverse weather conditions when the current direction and speed are accurately known.

It is also relevant in respect of port operations that ocean currents data is important to the optimum scheduling of cargo handling. The time estimated and efficiency of loading and unloading operations depend upon different current conditions. Thirdly, knowledge of ocean currents becomes important in the long term in developing the port, through expansion and improvement of its infrastructure, in order to design structures that can successfully resist the hydrodynamic forces developed by the flow of water.

Acoustic Doppler Current Profiler(ADCP) is a modern and convenient way of measuring ocean currents compared to traditional methods. It can provide detailed current information at different depths quickly and accurately, which is so vital for the efficient operation of Borongan Port.

3. How do ADCPs using the Doppler principle work?

The principle behind ADCPs is the Doppler effect. They send out acoustic signals into the water. These acoustic waves will interact with particles or other objects in the water that are moving with the ocean current. Upon reflection to the instrument, due to the Doppler effect, the waves change their frequency. From this change in frequency, it would determine the velocity of the ocean current at various levels of depth.

ADCP in Port Ocean Current Measurement: Shipborne ADCP Shipborne ADCPs are installed on ships operating in Borongan Port. As the ship moves around the port area, the ADCP continuously emits acoustic signals in different directions. It can measure the ocean current at multiple points along the ship's path and thus display a comprehensive view of the current distribution in the area covered by the movement of the ship.

Fixed ADCPs are usually set up at a particular site in the port, which is often at the bottom of the ocean near infrastructure with high importance or at any strategic point in the channel of water. They continuously monitor the conditions of the ocean current in that particular location over a long period. In this way, very valued data about regular patterns of the current and how it affects port facilities at that fixed point will be provided.

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

To be able to give high-quality measurement of the ocean currents in Borongan Port, there are certain characteristics needed for the equipment. First, the material used for the equipment should be reliable and able to resist the harsh marine environment: corrosion caused by sea water, pressure variations, and wave impact. The casing of ADCPs is made with a material like titanium alloy; hence, titanium alloy has huge strength with great corrosion resistance and is suitable for long working in the marine environment.

The equipment should be small in size, low in weight, and low in power consumption. The small size can be installed easily in different parts of the port, whether on ships or fixed locations. Low weight provides ease in handling and deployment, and with low power consumption, equipment can operate for a continuous period without frequent battery replacement or excessive power supply.

Thirdly, it is cost-effective in large-scale measurement. It is expected that the equipment will be reasonably priced to be installed in the port for obtaining comprehensive current data.

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

According to the Usage Purpose

• Shipborne ADCP: When the purpose is to conduct mobile measurements while the ship navigates in the port area for a fast acquisition of a general overview of the current situation in different parts of the port, then shipborne ADCP shall be applied. It covers a wide range of areas during the movement of the ship.
• Bottom-mounted ADCP: In applications where the monitoring of ocean current in a certain location of the port should be long-term and fixed-point, such as near important facilities or areas where the characteristics of current are to be monitored closely, bottom-mounted ADCP is more appropriate; thus, it can provide stable and continuous data at a fixed position.
• Buoy-mounted ADCP: In situations when it is not convenient to install fixed equipment on the seabed or on other structures, buoy-mounted ADCP can be used. The buoy-mounted ADCP can measure the ocean current in the upper layers of the water body and transmit the data wirelessly.

According to Different Frequencies

• In the water depths within 70m at Borongan Port, a 600kHz ADCP is generally enough to deliver the accurate data on current, as it operates within that depth.
• In the case of water depth of 110m, application of 300kHz ADCP becomes more relevant in capturing characteristics of water current.
• ADCP operating at 75kHz: If the water area has up to 1000m in water depth, it can reach this depth and get good records of currents.

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.