Application of ADCP to Ocean Current Measurement in Kavala Port

1. Where is Kavala Port?

Overview of Kavala Port

Kavala Port is situated in northern Greece. It is a port of considerable size and throughput. The port is an important link in the regional maritime transport network, handling a wide range of cargo, including agricultural products such as tobacco and grains, industrial goods, and containers.

It also means having been made well-connected with the facility of an efficient transportation system serving the hinterland for all of your commodities. The Port of Kavala aims for continuous safe services. It consists of service groups responsible for ensuring vessel traffic activities, cargo operations, along with infrastructure maintenance within the Port.

Port Facilities

Berths: The port has a number of berths designed to handle different types of vessels. In this respect, there are berths for medium-sized cargo ships and fishing vessels. These berths are fitted with mooring and docking facilities to ensure that the ships safely arrive and leave the port. The ships and the berths are protected during the process of docking and undocking by bollards and fenders.

Cargo-handling Equipment: There is a range of cargo-handling equipment along the quay. These include conveyor belts and forklifts, which are used in handling agricultural products, while cranes and other lifting equipment are used for industrial goods and containers.

Storage Facilities: In here, a number of storage areas assigned for various types of cargo is present. For agricultural produce, warehouses are well ventilated with controlled temperatures. In the case of containerized and other general cargos, the facilities include a container yard and storage sheds.

Channel and Navigation Aids: The channel is dredged to a depth and width that is appropriate for the safe passage of vessels. There are navigation aids such as buoys, beacons, and radar systems that guide the ships in and out of the port. The radar systems show the position and movement of other vessels in real time in the vicinity of the port.

2. Why do we have to measure the ocean currents in Kavala Port?

Importance for Port Operation and Management

Kavala Port measurement of the ocean currents is highly essential in regard to vessel safety. This includes speed and direction knowledge by captains approaching berths or maneuvering through the channel. A cross-current near a berth can make the process of docking both difficult and dangerous. For instance, a ship approaching a berth against a significant current may have to adjust the speed and angle of approach to ensure smooth and safe docking. Accurate current measurements allow captains to make informed decisions and reduce the risk of collisions and accidents.

Another point is that it's critical for streamlining the port's activities. Current information can enable much more effective scheduling of ships' arrivals and departures. Knowing what tidal currents and other regular flows, in advance, can enable port management to manage berthing better and plan loading/unloading with higher productivity since cargo - handling operations can be coordinated much more efficiently.

From an environmental point of view, in the event of an accidental discharge of pollutants like oil or chemicals, knowledge of ocean currents becomes very important. Given the nature of cargo handled at the port, prediction of the spread of a spill using current data can help in quickly instituting containment and mitigation measures to minimize environmental damage.

Acoustic Doppler Current Profilers represent an efficient method of current measurement as compared to traditional means.

3. How Do the ADCPs Based on Doppler Principle Work?

Measurement Principle

The ADCPs work on the principle of the Doppler effect. When an ADCP current profiler sends an acoustic signal into the water, it scatters with the moving particles of water. Due to the ocean current, these water particles are in motion and thus create a frequency shift of the reflected acoustic signal received back by the ADCP profiler. This frequency shift is related to the velocity of the water flow due to the Doppler effect.

Calculation of Current Speed and Direction

This frequency shift is analyzed by the ADCP current profiler for its magnitude and direction, enabling it to calculate the speed and direction of the ocean current at discrete points in the water column. It can give a profile of the ocean current - that is, how the current changes with depth - by transmitting signals from several angles and at numerous depths.

ADCP Deployment in the Port

Shipborne ADCP

The ADCP current meter could be installed on ships operating in the Kavala Port area. During the movement of the ship around the port, the ADCP flow meter continuously sends acoustic signals into the water underneath. The movement of the ship allows the ADCP current profiler to monitor a wide area and take current data from different locations. For example, during a routine survey of the port by a research or inspection ship equipped with a shipborne ADCP, it can gather data on the current patterns across various parts of the port, providing a comprehensive understanding of the water flow situation.

Fixed ADCP

The fixed ADCPs are deployed at particular stationary positions within the port, for instance, at the bed near crucial navigation areas or at the port's entrance and exit. These instruments of ADCP will continuously monitor ocean currents over long periods at fixed positions. These are useful in the study of regular current patterns at chosen locations of the port. For example, a bottom-moored ADCP installed near the entrance can measure the in and out currents, which is useful to know the characteristics of tidal effects and other steady-state flows in the area.

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

Equipment Requirements

For high-quality measurement of the currents in Kavala port, given equipment characteristics are essential: material reliability is the first one. The equipment should be able to resist the harsh marine conditions. Seawater contains salts and other chemicals that can corrode materials over time. Other conditions the equipment should be able to resist are the pressure variation at different water depth, and the mechanical forces due to waves and currents.

Secondly, a small-size and lightweight device with lower power consumption is desired. It means a compact size that makes its installation in the various locations within the port, on board of the ship, fixed structure such as piers, and on the seabed, easy. It is much lighter in weight to ease the installations and transportation. The use of low power consumption means the equipment could operate for continuous long periods with no need to replace the battery frequently or high-power supplies, especially applicable in the long-term monitoring situation. Cost is also another aspect. The option at lower cost thus enables the port to deploy more pieces of measuring devices to be used so that the monitoring of the current in more aspects at different places within the area of the port could be achieved.

The Advantage of Titanium Alloy for ADCP Casing

The casing of ADCPs is preferably made from titanium alloy. The use of titanium alloy in ADCPs results in excellent corrosion resistance; this means that even after a long exposure to seawater, the alloy can retain its structural strength and functionality. Its high strength - to - weight ratio allows for the construction of a durable yet relatively lightweight casing. For example, an ADCP current meter fitted with a casing made from a titanium alloy would work well in those parts of the Kavala port that are deeper and thus have higher water pressures, and provide current measurements with good accuracy.

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

Selection Based on Usage

Shipborne ADCP: Where the objective is to carry out wide-area surveys of the port waters while the ship is operational, shipborne ADCP shall be fit for the purpose. It would cover the various sections of the port as the ship moves around and can collect a large amount of data to provide a comprehensive understanding of the overall current situation in the port. It also helps in mapping the general pattern of flow and variations within different areas of the port waters.

Sitting bottom ADCP: Long- and fixed-point monitoring of a certain place in the port will be more appropriate, such as in areas around important infrastructure or areas showing complex current behaviors. They record continuously the current data at fixed positions, providing valuable insights into the local current characteristics and any changes over time.

Buoy-mounted ADCP: When it is not convenient to install fixed equipment on the seabed or on ships, buoy-mounted ADCPs can be used. They float on the water surface and can measure the currents in the upper layers of the water column. They are relatively easy to deploy and can be relocated if needed, making them suitable for monitoring certain dynamic or hard - to - reach areas within the port.

Selection Based on Frequency

A frequency choice for ADCPs would take into consideration the water depth, in this case, of Kavala port. Usually, if the water depth does not go beyond 70 meters, 600 kHz can be quite sufficient, giving reasonably accurate current measurement for this relatively shallow depth range. For deeper waters of up to about 110 meters, an ADCP with a frequency of 300 kHz is more advisable. In very deep sections of the port, with water depth reaching up to 1000 meters, an ADCP with a frequency of 75 kHz is recommended to ensure reliable profiling of the ocean currents at such great depths.

There are several well-known ADCP profiler brands in the market, such as Teledyne RDI, Nortek, and Sontek. However, there is also an excellent Chinese ADCP brand-China Sonar PandaADCP. It is made entirely of titanium alloy material, which not only ensures its durability in the marine environment but also offers an excellent cost-performance ratio. For more information, you can visit its official website: (https://china-sonar.com/).

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