ADCP's Application to Ocean Current Measurement in Damortis Port

1. Where is Damortis Port?

Damortis Port is a little coastal port located within the municipality of San Fabian, Pangasinan in the Philippines and an outlet for the local and regional water transportation requirements.

Scale of Port and Throughput

The port is moderately sized and caters to a wide array of cargo, from agriculture, mainly rice, vegetables, and fruits from the fertile plains of Pangasinan, to even handling fishery products because of its vibrant fishing industry. Outputs can be quite high in this port during peak months or seasons, especially when agricultural export is high or during months when a lot of fish is being landed.

It serves as a very important link in the transportation of goods to and from the local communities as well as other ports around the region. Its size and facilities are designed to take regular traffic of medium -sized cargo ships and fishing vessels.

Routes and Business

Damortis Port has shipping lanes with other domestic ports. This port acts an important part in the local trading network, by which good transportation is enabled between the different coastal and inland areas. Its major businesses include fishing and clearing of cargo. Fishing vessels operate from this port by unloading their catch and then replenishing the stock for further trips. In cargo, the same ships move agriculture and other local produce to other markets.

Besides, it can provide for minimal tourism-related activities: boating, excursions to the local coast points.

Port Management and Operation

It is managed at the level of local authorities of the port facility. Their tasks also involve the keeping of order among the vessels, assurance of effective and swift processes of the ships' berthing and mooring, supervision of cargo loading and unloading operations for their undamaged and timely processing.

They also involve in security matters aimed at securing the port and the assets within it. This is achieved by liaison with other law enforcement agencies and observation of safety measures that will ensure the security of the ships, port facilities, and personnel operating within and around the ports.

Port Facilities

It has a number of berths that can accommodate different types of vessels. There are areas of docking with piers and quays suitable for fishing boats and cargo ships. The port also has storage facilities for both perishable-like fish and produce-and non-perishable goods.

There are basic amenities such as a fish market for the local fishery trade, and also facilities for refueling vessels and fresh water. There may be some simple repair and maintenance workshops for boats.

Channel and Direct Navigation

Damortis Port has a well-defined channel for safe navigation. The channel is maintained to have an adequate depth for vessels, taking into account the tidal variations. Along the channel are placed buoys and beacons to guide ships entering and leaving the port. These will guide mariners in navigating directly and avoiding any shallow areas or any underwater obstruction.

2. Why do we have to measure the ocean currents in the Damortis port?

Safe Vessel Operations

The measurement of ocean currents around Damortis Port has been important for the safety in the operation of vessels. Knowledge of current direction and speed can easily allow precise berthing and mooring. By understanding the nature of the currents, the positioning of vessels during docking can be appropriately estimated by port operators to reduce incidents of collision with the port infrastructures or other vessels, especially given the nature of vessels using the facility-combined fishing and cargo.

Currents can also cause vessels to lose stability during mooring. Proper measurement of the currents allows for the making of appropriate adjustments to mooring lines and other safety measures in keeping these ships secure.

Benefits to the Fishing Industry

The understanding of ocean currents is very significant for local fishing. Currents carry nutrients and influence the distribution of fish and other marine organisms. By accurate measurement of currents, fishermen are able to identify areas of higher concentrations of fish, which helps increase their catch and productivity.

This again will impact the time and fuel consumed by fishing vessels while traveling due to the currents' directions and speed. This will, in turn, help fishermen during the scheduling of their trips with more economy.

Infrastructure and Environmental Considerations

From an infrastructural point of view, the measurements currently yield very good data on the maintenance and future planning of port structures. Currents can exert hydrodynamic forces on quay walls, piers, and other facilities in such a way that their stability and durability are affected during a long period. Having current data, the port authority will be able to design more robust infrastructure and plan preventive maintenance to extend the life of those structures.

It helps in understanding the dispersion of pollutants in port waters. Knowledge of the current pattern aids in employing effective containment and cleanup efforts in the event of an oil spill or other contaminant release. It helps in monitoring the impact of port activities on the surrounding marine ecosystem.

The ADCP current meter therefore offers a more modern and handy technique of measurement compared to traditional methods. It provides detailed and real-time information about the profile of the current; hence, the monitoring of the ocean currents within the port area will be much more efficient and more precise.

3. How do ADCPs using the Doppler principle work?

ADCPs work on the principle of the Doppler effect. They send acoustic signals into the water. As these acoustic waves encounter and interact with moving particles in the water, such as suspended sediments or small organisms, the frequency of the reflected waves shifts due to the Doppler effect.

This frequency shift of the reflected signals is measured by the ADCP meter. By using specific algorithms and calibration, it can determine the velocity of the moving particles. Because the movement of these particles is due mostly to the ocean current, the ADCP can determine the velocity of the current.

ADCP in Port Ocean Current Measurement

Shipborne ADCP

Shipborne ADCPs are installed on vessels operating in the port area. During motion, an ADCP current profiler steadily emits pulses of acoustic energy in various directions, both downwards and sideways from the ship. It detects current velocities from different depths throughout the path traveled by a ship. The data gathered en route can later be used to create a detailed mapping of the current field in a port area for real understanding of current patterns during the voyage of a ship.

Fixed ADCP

Fixed ADCPs are deployed at fixed locations in the port, either on the seabed or mounted on fixed structures such as piers or breakwaters. These record the ocean currents at that location as a function of time. Fixed ADCPs are useful for the long-term and steady current conditions at key points in the port. This data can provide a reference for port operations, research, and infrastructure planning.

4. What's needed for high-quality measurement of Damortis port currents?

Equipment Requirements

The equipment, to provide quality measurement of the ocean currents in Damortis Port, must be made with reliable materials. These have to resist the hostility of the sea, such as salinity, high pressures that exist at depth, and possibly the impacts due to floating objects. Other considerations are the size and weight of the equipment. Smaller in size and lighter in weight, especially for vessel installation or fixed structure installations where space is limited, are an added advantage in flexibility for the placement of the equipment.

Another important factor is power consumption. A low-power-consuming device is ideal since it can work for extended hours without always changing batteries or requiring too much energy. This is essential in the fixed ADCPs since it may not be easy to provide a constant power supply to them.

Advantage of Titanium Alloy Casing

The best ADCPs are those whose casing is made of titanium alloy. The corrosion resistance of the titanium alloy is excellent; it can bear the action of seawater for many years without destruction. All this helps to keep ADCP profiler safe and maintains its operation. It has a high strength-to-weight ratio, thus permitting a durable and lightweight design, which is important in the installation and operating contexts. Also, the high pressure at greater depths is resisted by the titanium alloy, hence making it suitable for use in different water depth conditions of the port area.

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

Based on Usage

Shipborne ADCP: This is the best where it serves the purpose for a general overview of current patterns at the instance of vessel traffic. Thus, by that, this will enable areas of a different look into the ports as it gets closer while giving it a more general look, wide ranging about the present status of currents in the respective place.

Bottom-mounted (Sitting on the seabed) ADCP: In order to conduct long-term and continuous monitoring of current conditions at certain fixed locations, such as near important port structures or in areas where the characteristics of the current are of particular interest for research or operational reference, bottom-mounted ADCPs would be more suitable. They can provide stable and consistent data over an extended period.

Buoy-mounted ADCP: When currents are required to be measured in areas inaccessible for fixed installations or by operations by ships, then ADCPs mounted on buoys are deployed. These can then move with the currents to some degree while collecting data and provide information of variation in currents in those regions.

Based on Frequency

In the case of water depth up to 70 meters, it is generally advisable to use an ADCP with a frequency of 600 kHz. It will provide very detail and accurate current measurements due to the relatively shallow area of the port.

For water to a depth of 110 meters, the more appropriate one should be a 300 kHz ADCP. It provides better penetration of the water column to acquire reliable current data for those water depths.

In areas with water deeper up to 1000 meters, the best option would be an ADCP with a frequency of 75 kHz. The instrument is capable of tackling such enormous depth ranges with an ocean current measurement satisfying the accuracy required.

There are several well-known ADCP brands in the market, such as Teledyne RDI, Nortek, and Sontek. However, it's worth mentioning a cost-effective Chinese ADCP brand-China Sonar PandaADCP. It is made of all-titanium alloy material and offers an impressive price-performance ratio. You can visit its website at (https://china-sonar.com/) for more information.

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