Application of ADCP to Ocean Current Measurement in the Port of Valentia

1. Where is Valentia port?

The Valentia port is located on Valentia Island in County Kerry Ireland. It is a significant coastal port with a long history in shipping.

Port Scale and Throughput

This port falls into the category of medium activity levels. A great diversity of cargoes are handled in the facility: local farm produce like milk and animal husbandry and fresh catches. These are supplemented by building materials and all the necessary supplies for which the basic infrastructure and daily needs of the island create a demand. The annual throughput is essential to the local economy for facilitating trade and commerce in the area.

Routes and Business

The Valentia port is connected to other Irish ports and some trade links with ports across the Irish Sea and further afield. The business sectors of the port are varied in nature, with fishing being the most predominant. The local fishing fleet operates from this port, and a considerable quantity of fish and seafood is processed and exported from here. Import activities concern goods needed for the island's development and daily life, such as fuel and machinery.

Port Management and Operation

The port is managed on the basis of safety and efficiency. The management team oversees cargo handling to ensure that ships are efficiently loaded and unloaded. They also make sure that vessels docking and operating within the port area adhere to strict safety regulations. Regular maintenance of port facilities and infrastructure is carried out to keep everything in good working order.

Port Facilities

It has a well-equipped fishing harbor with berthing spaces for different-sized fishing boats. There are fish-processing facilities with cold-storage units to maintain the freshness of the catch. For general cargo, there are quay areas with appropriate loading and unloading equipment. The port also provides basic services such as fuel supply and access to fresh water for the vessels.

Channel and Navigation

The channel to the port is dredged for safe passage of ships. Aids to navigation like buoys and lights are available to direct the vessels which can then head directly in and out of the port in safety. This is very important for the smooth running of fishing boats apart from other cargo ships.

2. Why should we measure the ocean currents in the Valentia port?

Fishing Industry Advantages

Measurements in Valentia have shown great importance in the fishing industries. Currents in bodies of water help with fish distribution. They help to bring in a lot of nutrients and plankton, which happen to be their main food sources. It provides fishermen with the chances to locate fishes because understanding the pattern of current provides possible locations where fish might flock. For example, areas with upwelling currents, which carry nutrient-rich waters to the surface, are often hotspots for fishing. This may increase the catch and productivity of the fishermen by a big margin.

Vessel Navigation and Safety

Present measurements are also vital for the vessels operating in the port to be able to navigate safely and efficiently. Currents can alter the speed and direction a ship is taking during both docking and undocking. Precise current data allows the port authorities to give better instructions to the captains, minimizes accidents, and provides vessels with the ability to move smoothly.

Infrastructure Protection

With the influence of these ocean currents, this may lead to eventual structural degradation of the quay walls and berths in this port. Observation of the currents allows the port management to easily locate sites which are more prone to erosion or any other type of damage. In such cases, they will easily reinforce structures or adjust the schedules for maintenance in protecting such infrastructure and hence extending the life.

Thus, this Acoustic Doppler Current Profiler (ADCP) provides a means of measuring ocean currents by a considerably advanced technique as opposed to older systems. It would give, furthermore, very detailed and therefore real-time speeds and directions of the currents of the ocean at depths at short intervals, which would prove quite helpful for port operations and the fishing communities as well.

3. How do the Doppler principle-based ADCPs work?

They basically work on the principal of Doppler. An ADCP current meter is transmitting acoustic signals into water. Acoustic waves meeting particles carrying this ocean current - essentially, the suspended sediments or small organisms - are in an interactive mode.

The Doppler effect alters the frequency of such reflected waves when acoustic waves emitted are reflected back after striking moving particles. An ADCP measures the frequency shift between the signal emitted and what is received, and through a chain of algorithms, it finds the velocity of the moving particle. The velocities measured again are used to deduce the velocity and direction of the ocean currents.

In Valentia port there are mainly two ways of the usage of ADCPs, as:

Ship-borne ADCP

An ADCP current profiler deployed on a fishing boat or any other small survey vessel could do the measurement exercise around the port area and the waters adjoining it. The instrument would continuously emit acoustic signals and receive them back in modified states while the boat runs across the area. For example, data are given on current information on a range of locations that the boat goes past, giving good mapping of the currents within the wide area of a port and its surroundings.

Fixed ADCP

A bottom-mounted ADCP flow meter with definite placement near the port entrance, or any hot location. It operates uninterruptedly while monitoring current situations over single points. For an individual sector, it shall grant longer-termed regular current character data; as opposed to this, their data contributes in a meaningful fashion, not for monitoring current fluctuations as most fixed records come closer or equal in variation as other instruments.

4. What is necessary for the quality measurement of currents at the Valentia port?

Quality Equipment Materials

The equipment should be made from reliable materials for high-quality current measurement in Valentia port. Since seawater is corrosive and the environmental conditions vary from time to time, the equipment should be able to bear such conditions. It is also advantageous to have compact size. As the space is limited at certain areas of the port, a smaller-sized ADCP can be installed easily whether on a vessel or fixed location.

The other features the equipment must possess are light of weight and low power consumption. For ship-borne ADCPs, lighter weight would imply lesser effects on vessel stability and handling. For fixed ADCPs that have to operate continuously, low power consumption will be required. This would lower the cost and complexities of power supply systems.

Casing made of Titanium Alloy

For the casing material, it would be appropriate to use titanium alloy. Withstanding adverse marine conditions calls for a high corrosion-resistant ability. It has a relatively high strength-to-weight ratio important in designing a strong yet light casing. It is also capable of supporting pressure and impacts that the equipment faces in the waters of the port.

5. Selection of Equipment for Current Measurement Based on Usage Scenarios?

Ship-borne ADCP: If the objective is to conduct surveys of a larger area of the port and its surrounding waters, then a ship - borne ADCP can be considered as a good option. A ship - borne ADCP can be mounted during fishing trips or routine port surveys to capture current data over a large swath.

Bottom-mounted (sit-on-bottom) ADCP: In these cases, a bottom-mounted ADCP would be appropriate for monitoring the current long-term at fixed positions, such as in the entrance of the port or in proximity to the important berths. With it, there is an unbroken flow of data about the local current situation.

Buoy-mounted ADCP: In cases where the measurement point has to be flexible and movable, a buoy-mounted ADCP could be used. It can be deployed in various parts of the port waters, according to needs.

Frequency Selection

Water depth up to 70m: often, a 600kHz ADCP is suitable.

For depths up to 110m, a 300kHz ADCP would be more appropriate.

It will work at depths up to 1000m for a 75kHz ADCP.

Well-known brands include Teledyne RDI, Nortek and Sontek. One Chinese brand is worthy of mention however: China Sonar Panda ADCP. The China Sonar PandaADCP is all-titanium alloy in construction; this would seem to imply a robust and reliable machine in the saltwater environment. The value-for-money reputation of this model is also very good. You can learn more at its website: (https://china-sonar.com/).

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