Application of ADCP to Ocean Current Measurement in Alicante Port

1. Where is Alicante Port?

Alicante Port is located along the southeastern coast of Spain, abutting the Mediterranean Sea. It is quite a well-renowned port with both commercial and tourist purposes.

Port Scale and Throughput

The port scale is medium to high in terms of throughput. It deals in a wide array of cargo: containers, general cargo like building materials and machinery, and also a lot of cargo related to the local agricultural and industrial concerns. The cargo volume is impressive, with the continuous arrival of vessels of various sizes during the year. Added to that, it is also a favorite cruise liner port, adding to its total traffic and economic importance.

Routes and Business

Alicante Port is integrated with various national and international routes. Besides, this also forms one of the key links in trade dealings between Spain and other Mediterranean countries. The variety of business dealings in cargo handling and the logistics business as well as those linked with the cruise ship industry form versatile businesses here. These facilities range from warehouses and customs to maintenance facilities for ships. The cruise sector can accommodate berthing capacity for thousands of passengers with facilities in terminals offering shops, restaurants, and tourist information offices.

Management and Operation of the Port

The port is well organized and has its focus on safety and quality services. The system of traffic control is good, organizing the flow of ships whether cargo vessels or cruise liners. The port authority was responsible for maintaining the infrastructures like deep-water berths, quays, and storage areas and adherence to environmental and security concerns protecting the port and its surroundings.

Port Facilities

Modern facilities have been fitted out in the port. It contains deep-water berths, capable of handling big container ships and cruise vessels. It contains various types of cargo-handling equipment like cranes, forklifts, and conveyor belts, among others, that ensure speed and efficiency in loading and unloading goods. For storage, it has big general warehouses and temperature-controlled areas for perishable items. The passengers of cruise vessels can avail themselves of comfortable waiting halls, restaurants, and shops.

Channel and Direct Navigation

The channel of Alicante Port is well looked after; therefore, access to the facility is very safe for ships. The depth of the channel allows vessels with big drafts to enter and leave the port. Aids to navigation include buoys, lighthouses, and radar systems installed to guide the ships' entrances and exits in and out of the port. There is direct navigation to and from other Mediterranean ports; thus, it forms a convenient call for ships cruising down the coast.

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

Measuring ocean currents is very significant in Alicante Port. For navigational purposes of ships, one has to clearly understand the currents' behavior for efficient and safe transportation. Based on this information, captains can work out their routing more accurately and effect all the necessary changes in speed and course accordingly. For example, knowledge of the currents will ensure that passengers are comfortable on a cruise ship when approaching or leaving the port area.

Accurate current measurement is important for the docking and undocking of ships in port operations. Tugboats need information on current conditions for effective assistance, which will guarantee the safe movement of vessels. For moored ships, knowledge of the currents provides information about the appropriate mooring arrangements to avoid drifting of ships, which could lead to damage to the port infrastructure or other vessels.

From an environmental point of view, the actual measurements are fundamental to the management of waste within the port, and pollution is under control. Currents affect the dispersion of pollutants and the movement of sediments. In this respect, current measurement allows for a better disposal of waste from the port and avoids sediment accumulation processes that could lead to a depth reduction in either the channel or the berths. Thus, ADCP current meter represents a means for more accurately and efficiently performing such current measurements than traditional methods.

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

The ADCPs apply the principle of the Doppler. They emit acoustic pulses through the water column. These pulses scatter off particles in the water, like suspended sediments, plankton, or other small objects. Due to the fact that these particles move with the water current, the frequency of the reflected sound waves changes due to the Doppler effect.

The ADCP measures the frequency difference between the emitted and received frequencies. By applying the Doppler equation it estimates the velocity of the particles which is proportional to the water current velocity. Thus ADCP flow meter estimates the current velocity at different depth within the water column and hence it provides the vertical profile of the current.

Ship-borne ADCP

The ADCP is installed on a vessel when an ADCP current profiler has to be used. During its movement around the port area, the ADCP continuously emits and receives acoustic signals. The continuous data during the movement of the ship gives the detailed view of the current pattern in different areas of the port. This type of ADCP profiler is generally used for the survey of the wide area, as well as to obtain real-time data of the currents.

Fixed ADCP

Fixed ADCPs are installed in the determined places in the port, on the seabed, or on a pier. The ADCPs allow for the determination of currents at a particular point continuously. They are valuable in monitoring long-term current patterns in areas of high traffic or near critical port infrastructure, such as at the entrance of the channel or the berths.

4. What is necessary for high-quality measurement of the currents in the port of Alicante?

Several characteristics are desirable with regard to high-quality current measurements in Alicante port. Reliability of equipment material is essential for the resistance against harsh conditions within a marine environment. The size of the equipment has to be small in order to assist in easy installations, especially at those points in the ships or areas in the ports that are out of space.

The weight of the ADCP meter should not be much heavy to lighten the installation processes and to lessen the load of the supporting structure. The consumption of power should be low to allow for continuous operations without a big power supply. Cost-effectiveness is very important since several units may be deployed by the port for adequate measurement of current.

The casing of the ADCP shall be made of a titanium alloy. Titanium alloy gives excellent resistance to corrosion, which is very important in a salt-exposure oceanic environment. Besides, it is strong enough yet light, so it also satisfies the needs of strength with lightness and ease of installation.

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

Based on Usage Purpose

• Ship-borne ADCP: It is appropriate for mobile measurements. It is best applied to ships that are normally in motion within the port area, like container ships, cruise ships, and general cargo ships. The shipborne ADCP provides a means of measuring currents along the ship's track, useful in understanding the overall current patterns in the port.
• Bottom-mounted ADCP: These are for fixed-point measurements. They are installed on the seabed near the docks, channels, or any other critical port infrastructures. These bottom-mounted ADCPs continuously provide data about the currents at a place and thus play an important role in monitoring the local current condition.
• Buoy-based ADCP: Buoy-based ADCPs are suitable for areas where fixed-bottom or ship-borne ADCPs are not convenient to install. They can provide current measurements in open water areas of the port and are relatively easy to deploy and maintain.

Based on Frequency

The choice of frequency depends on the water depth. In Alicante port, a 600kHz ADCP will be appropriate for water depths up to 70m, which could be applied for the shallower areas near the shores or inner parts of the port. An ADCP of 300kHz is suitable for water depths up to 110m and can cover a wider range of depths. For deeper waters in the port area, a 75kHz ADCP will be suitable for water depths up to 1000m and can be used in areas such as the approach channels.

There are well-known ADCP brands like Teledyne RDI, Nortek, and Sontek. However, a Chinese brand, China Sonar PandaADCP, is also a great option. It is made of all-titanium alloy material, providing excellent durability and a high level of corrosion resistance. It also offers an attractive cost-performance ratio. You can visit their website (https://china-sonar.com/) for more details.

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