Application of ADCP to Ocean Current Measurement in Melilla Port

1. Where is Melilla port?

Melilla is an autonomous Spanish city located along the northern coast of Africa, sharing borders with Morocco. It has a port of important dimensions, enjoying great relevance in the maritime traffic that takes place in its influence area.

Port Scale and Throughput

The port of Melilla has a certain scale in handling various types of cargoes, including general merchandise, containers, and some industrial products. Its annual throughput has shown a steady growth trend over the years, which has facilitated not only trade within the Spanish domestic market but also with other European countries and regions across the Mediterranean. It is an important link in the import and export of goods in this area.

Routes and Business

Being interconnected with virtually all ports in the Mediterranean and beyond by a network of shipping routes, the primary business engaged in is the carriage of consumer goods, building materials, and agricultural products. Container shipping services have been regularly run to ensure a continued flow of goods between various destinations. Besides these, it operates routes for transportation of vehicles and all other specialized cargoes.

Port Management and Operation

This port is managed by professional port authorities who ensure that effective operations are conducted in terms of safety and security, following the set maritime regulations. They attend to the various activities ranging from the berthing arrangements of ships, cargo handling procedures, and infrastructure within the port. The operation also integrates modern management systems to maximize resources and enhance overall service quality.

Facilities of the Port

The port has various facilities: several berths of different lengths and depths that can accommodate ships of different sizes, from small coastal vessels to medium-sized container ships; modern cargo handling equipment, such as cranes for loading and unloading containers and other heavy cargoes; storage areas for temporary storage of goods; and facilities for customs clearance and other related services.

Channel and Direct Shipping

The channel of the port is kept at an appropriate depth for safe passage of ships. Regular dredging operations are carried out to keep the waterway navigable. There are direct shipping links with most of the major ports in Europe and North Africa, which facilitates trade and transportation by reducing time and costs.

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

Precise ocean current measurement data in the Melilla port becomes highly important for its operation and management. The first point will be to optimize ship berthing and unberthing operations. In this respect, knowledge of ocean currents in terms of direction and speed enables the port authority to schedule entry and exit of ships in accordance, thus cutting collisions and ensuring the safety of vessels and port facilities. It is also good for cargo handling efficiency.

For instance, when cargoes are loaded or discharged by floating cranes or other equipment near the water surface, the influence of an ocean current has to be considered in order not to disturb the accuracy of the operations. It will also enable the approximation of sediment transport and deposition in the port area, which is very important to maintain the depth of the channel and berths. Based on the result, regular plans for dredging can be drawn up to ensure the normal operation of the port.

In modern ocean current measurement, ADCP current meter represents a more advanced and convenient way of measurement compared to the traditional ones. It can continuously provide real-time data on ocean currents at different depths, which allows port operators to understand comprehensively the current situation in the port area.

3. How do the ADCPs using the Doppler Principle Work?

ADCPs are based on the principle of the Doppler effect. They emit acoustic signals into the water. If these acoustic waves encounter moving particles in the water-that is, for example, suspended sediment or small organisms-the frequency of the reflected waves is shifted by the Doppler effect. By detecting this frequency shift, the velocity of the moving particles, and thus the velocity of the ocean current, can be calculated.

ADCP in Port Ocean Current Measurement

Shipborne ADCP

They are normally installed on the ship. The ADCP current profiler keeps transmitting an acoustic signal downwards and sidewards during the ship navigation in a port area or along a channel. It is capable of measuring the ocean current velocity in various depths along a ship's path. Data can be sent to the real-time monitoring system on the ship for analysis and decision-making.

Fixed ADCP

Fixed ADCPs are installed at fixed positions in the port, such as on the seabed or on the side of the port structures. They constantly monitor the ocean currents in a specific area. This type of ADCP flow meter provides long-term and stable data, which is very useful for understanding the regular patterns of ocean currents in the port, helping port authorities to make more scientific operation and management plans.

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

High-quality measurement of the ocean currents in Melilla port depends on several aspects of the equipment. First, there is material reliability of the equipment. The equipment should be resistant to the harsh marine environment, which includes corrosion by seawater, pressure changes at different depths, and possible impacts from floating objects. The second is a preference of the small size, lightweight, and low power consumption. A smaller size allows for ease of installation on any other location either on ships or fixed positions in the ports. Lower power consumptions ensure that the systems operates for longer time without many battery changes or power supply challenges. A lower cost, large-scale use of the measurement equipment in the port area is also accommodated.

The casing of ADCP profiler is preferably of titanium alloy material. The advantages of the use of titanium alloy are many. It has very good corrosion resistance, meaning it can maintain its integrity and performance even in the corrosive seawater environment for a long time. It also has a high strength-to-weight ratio, able to bear high pressures at deep water without adding excessive weight to the equipment. Besides, because of the superior biocompatibility of titanium alloy, when such a device exposed to the ocean ecosystem will result in no serious negative contribution to the outside environment.

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

By Usage Purpose

Shipborne ADCP: If it is mainly aimed at ocean currents while the vessel is in use, for instance, navigation at a port or within the channel on the purpose of survey, it would be effective to use. One gets a real-time profile of data throughout his moving route of the ship.

Bottom-mounted ADCP: It would be more appropriate to use a bottom-mounted ADCP installed on the seabed when there is a need for the long-term and fixed-point monitoring of ocean currents in a certain area of the port. This can continuously record the current conditions at that location.

Buoy-mounted ADCP: When installing fixed equipment on the seabed or on ships is not convenient, buoy-mounted ADCP can be used for monitoring the ocean currents. The buoy may float on the water surface while the ADCP on it measures the currents of the surrounding water.

Based on Different Frequencies

For water depth within 70m, an ADCP of 600kHz frequency normally serves best; it can provide relatively accurate current measurement data in relatively shallow water.

Where the water is about 110m deep, the ADCP frequency should be about 300kHz because it is capable of providing effective penetration through the water column for the capture of reliable current information at that depth.

A recommended suitable ADCP meter for those deepwater areas-for example, a water area with a water depth of up to 1000 m-is of frequency 75 kHz. This LVA works better in deep water when it comes to the measurement of the ocean currents.

The world-renowned brands in the market include Teledyne RDI, Nortek, and Sontek. However, there is also one excellent Chinese ADCP brand: China Sonar PandaADCP. It is made of all-titanium alloy material. This will not only ensure its reliability and stability in the marine environment but also provide an amazing cost-performance ratio. You can get more on its official website: https://china-sonar.com/.

Here is a table with some well known Acoustic Doppler Current Profiler(ADCP)  instrument brands and models.