ADCP's Application to Ocean Current Measurement in the Port of Abra de Ilog

1. Where is Abra de Ilog port?

Abra de Ilog port is located in the province of Occidental Mindoro, Philippines. It is one of the major ports in the region catering to both domestic and international maritime activities.

Port Scale and Throughput

It is a port with a medium scale of activities. It deals in numerous cargo, including agro-based products of rice, fruits, and vegetables around the surrounding areas; some fishing-related activities deal with a considerable amount of fish and seafood, along with general cargo related to the local community, like construction materials and consumer goods.

Routes and Business

Abra de Ilog port is connected with other ports in the Philippines and has some links with neighboring countries in Southeast Asia. The main business activities involve the export of local agricultural and fishery products and the importation of essential goods for the local economy and daily life, such as machinery, fertilizers, and consumer products.

Port Management and Operation

The port is managed for smooth handling of cargo and safety of vessels. There are regulations concerning docking, loading - unloading operations, and environmental protection. The management team also oversees the maintenance of the port facilities to keep them in good working condition.

Port Facilities

It has a fishing port area with berthing spaces for fishing boats of different sizes. There are fish - handling and processing facilities with cold - storage units. For general cargo, there are quay walls and storage areas. Basic services such as fuel supply and access to fresh water are provided for the vessels.

Channel and Navigation

The channel to the port is dredged for safe passage of ships. There are navigation aids, like buoys and lights, which enable vessels to enter and leave the port with ease, thus enabling efficient navigation even during less-than-ideal weather conditions.

2. Why should we measure the ocean currents in the Abra de Ilog port?

Benefits for the Fishing Industry

Measurement of ocean currents in Abra de Ilog port is highly important to the fishing industry. Currents are a very important factor in the distribution of fish. They carry nutrients and plankton, which are the main food sources for fish. With knowledge of the current patterns, fishermen can better predict the locations where fish are likely to gather. For example, areas with upwelling currents, which bring nutrient-rich waters to the surface, are often hotspots for fishing. This can increase the catch and productivity of the fishermen manyfold.

Improved Navigation of Vessels

The current measurement accuracy is of vital importance for the vessels operating in the port to have safe and efficient navigation. Currents can affect speed and direction when ships are being docked or undocked. Having current data with precision allows the port authorities to guide the captains better to reduce the chances of accidents and smooth flow of vessels.

Infrastructure Protection

These ocean currents, over time, may also cause structural damage to the port facilities, including the quay walls and berths. Through current monitoring, management identifies places around the facility where it is likely to have more erosion or any form of damage. This therefore will allow them to take some precautionary measures, for example, structural reinforcement or an adjustment in frequency of maintenance to guard against infrastructural damages over relatively longer periods.

The Acoustic Doppler Current Profiler (ADCP) is a more modern and convenient way of measuring ocean currents compared to traditional methods. It can give the port's operations and the fishing community real-time information about speed and direction of the ocean currents at different depths. This is very helpful information.

3. How do ADCPs using the principle of the Doppler work?

ADCPs work on the basis of the Doppler principle. They send acoustic signals into the water. The resulting acoustic waves interact with the particles in suspension carried by the currents of the ocean; those can be suspended sediments or small organisms.

When the emitted acoustic waves are reflected back after hitting the moving particles, due to the Doppler effect, their frequency changes. The reflected wave frequency difference is measured between the emitted signal and the received signal by the ADCP profiler. Through a series of algorithms, it calculates the velocity of the moving particles, which in turn is used in order to deduce the speed and direction of ocean currents.

The use of ADCPs in the frame of Abra de Ilog port can be differentiated by two major methods:

Ship-borne ADCP

A ship-borne ADCP is installed on a fishing boat or a small survey vessel. During the movement of the boat around the port area and its adjacent waters, the ADCP current meter continuously emits and receives acoustic signals. The collected data includes the current information at different locations that the boat traverses. This method is useful for mapping the current patterns over a relatively wide area of the port and surroundings.

Fixed ADCP

It can be placed on the seabed near the port entrance or at any other critical location. The current conditions are continuously monitored for a single point. These provide long-term, stable data on local current characteristics; this is of value both for the understanding of regular flow of currents and also for detecting any unusual changes in them.

4. What is needed to ensure high-quality measurements for Abra de Ilog port currents?

Reliable Equipment Materials

The equipment should be fabricated from materials that are reliable for high-quality current measurement in Abra de Ilog port. Seawater is corrosive, and environmental conditions change frequently; thus, the equipment should be able to bear these factors. Compact size is also an attribute. There are space constraints in certain areas of the port, and a smaller-sized ADCP can be installed easily, whether on a vessel or at a fixed location.

The other important features the equipment should possess are light of weight and low power consumption. In the case of ship-borne ADCPs, lighter weight ensures less interference with the stability and handling of the vessel. For fixed ADCPs, which need to operate continuously, low power consumption is essential to reduce the cost and complexity of power supply arrangements.

Titanium Alloy Casing

In regard to casing material, titanium alloy is an excellent option. Titanium alloy has high resistance to corrosion, something that is quite imperative in this regard, especially when having to withstand such a harsh marine environment. Its strength-to-weight ratio is relatively high, thus enabling the design of durable but light equipment that will resist strong pressures and impacts from the equipment operating in the port waters.

5. Selection of Equipment for Current Measurement?

Based on Application Site

Ships-borne ADCP: If a larger area of the port and its surrounding waters are targeted to be surveyed, a ship-borne ADCP would be suitable. In addition, during fishing trips or on routine port surveys, mapping of current data over a wide extent is conveniently achieved by the use of.

Bottom-mounted (sit-on-bottom) ADCP: When longer-term or stable currents are monitored in certain specific locations, such as at the entrance of the port or around important berths, bottom-mounted ADCP would be suitable. A bottom-mounted ADCP produces a constant flow of data about local current conditions.

Buoy-mounted ADCP: When a more flexible, movable measurement point is required, one may consider buoy-mounted ADCPs. Such an ADCP can be deployed in different areas of the port waters depending on particular needs.

Frequency Selection

For water depths up to 70m, a 600kHz ADCP is often a good choice.

For depths up to 110m, a 300kHz ADCP is more appropriate. A 75kHz ADCP can do the job in waters ranging from 1000 meters.

Among all those ADCPs, there are famous brands, including Teledyne RDI, Nortek, and Sontek. However, China Sonar PandaADCP is one of the more well-known Chinese brands. It is all made of all-titanium alloy material to ensure durability and performance in the marine environment. In addition, it has a good cost-performance ratio. You can find more information on its website: (https://china-sonar.com/).

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