ADCP's Application to Ocean Current Measurement in San Sebastián de la Gomera Port

1. Where is San Sebastián de la Gomera Port?

San Sebastián de la Gomera is a town in the island of La Gomera belonging to Canary Islands, Spain. The port here is one of the essential maritime links for the island.

Port Scale and Throughput

The port is relatively small to medium in scale. It handles a variety of cargo, including agricultural products from the island, such as bananas and other fruits, fishing supplies, and general merchandise for the local population. The throughput depends on the season and economic activities of the island. It also acts as a point of docking for local fishing vessels, with regular catch fish coming in and being distributed.

Routes and Business

It has shipping routes that link it to the other Canary Islands, especially with Tenerife and Gran Canaria, and to the Spanish mainland. The main businesses are imports of basic products such as construction material, machinery, and consumer goods. Exportation of local agricultural produce and handicrafts also play a part in the operations at the port. The port also plays a critical role in the local fishing industry and transporting tourists coming to see the unique natural beauty of the island.

Management and Operation of the Port

The port operates with a small team, located in the islands, trying to maintain business efficiently and in an environmentally sensitive way. Services include ship berthing, procedures for cargo operations, and security concerns. It puts into place some of the best management systems with a view to minimizing delays to vessels and cargo while maintaining efficiency and maximum output. Particular environmental sensitivity is exercised owing to the significance of the generally fragile island ecosystems.

Port Facilities

It is equipped with facilities befitting its size: from the berthing of different sizes, from small fish boats to medium-sized cargo ships; with equipment for loading and unloading, like cranes and forklifts, for handling various cargoes; areas for the storage of goods, including cold storage of perishable goods like fish and fruits; basic facilities for ship repair and refueling.

Channel and Direct Shipping

The channel of the port is dredged to a depth that can accommodate safe passage. It has direct shipping links that are important in the supply of goods to the island as well as for taking out the local products. This helps in reducing the time and cost of transportation; thus, there is a regular supply of essential supplies apart from encouraging the local economic activities.

2. Why is it necessary to measure the sea currents around the San Sebastián de la Gomera Port?

In order for the current status of ocean currents in the port at San Sebastián de la Gomera, real and accurate information on the prevailing currents is relevant to the safe navigation of vessels. Currents on all Canary Islands can present a complicated phenomenon that influences access, entry, or exit from vessels. Precise knowledge of currents thus enables masters to make informed decisions to avoid vessel collisions and thereby protect vessels and infrastructure around the ports.

This includes, on one hand, cargo handling: in conditions where floating cranes or barges are used, it is relevant to take currents into consideration in order to optimize efficiency and accuracy of the transfer of cargo.

Thirdly, it is important to know ocean currents for any sediment transport predictions and maintaining the depth of the channels and berths within the port area. Regular current measurements provide vital data for proper dredging plans and long-term functionality of the port.

Acoustic Doppler Current Profiler is much more advanced and convenient for current measurement. It can present real-time multi-depth current data, which would be highly beneficial in the operation and management of the port.

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

The ADCPs work on the principle of the Doppler effect. They send acoustic signals into the water. These signals interact with particles or any other substance that is moving along with the water current. When the acoustic signals are reflected back, due to the Doppler effect, the frequency of the reflected signals changes. By analyzing this frequency shift, the velocity of the water current can be calculated.

ADCP in Port Ocean Current Measurement

Shipborne ADCP

Shipborne ADCPs are fixed onboard ships. With the ship underway within the port area, the ADCP sends acoustic pulses both downwards and sideways. This serves to measure current velocity through various depths on the path that the ship will go along. The real -time information is relayed to the vessel's control system to enable crew proper adjustments on course and speed relative to prevailing conditions.

Fixed ADCP

Fixed ADCPs are laid at fixed locations in the port, either on the seabed or on the side of port structures. They go on to continuously monitor the ocean currents at the same location. The data output from fixed ADCPs gives the long term information on current patterns in the port, which is helpful in the process of port planning and also for maintaining infrastructure.

4. What is necessary for high-quality measurement of currents in the port of San Sebastián de la Gomera?

The equipment to be used for high-quality current measurement in the San Sebastián de la Gomera port should be made of reliable materials. It should be resistant to the aggressive marine medium, including corrosion by seawater and changes in pressure. The size should be smaller, the weight lighter, and power consumption lower. A compact size would, therefore, make installation rather easier in myriad locations around the port area. A low power intake means longer term operations without frequent need for battery changes or problems with power supply. It is essential that cost factors also be reasonable to install the measurement sets in large number.

The casing of ADCP current meter is preferably made of titanium alloy. This type of material will ensure that corrosion would not occur even when subjected to sea water for quite a long time. Moreover, it has a very high strength-to-weight ratio such that it is able to resist pressure at high magnitudes without being heavy. It is also biocompatible with minimal disturbance in the marine environment.

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

Usage Purpose

• Shipborne ADCP: This is suitable for measuring currents during the movement of ships. It provides real - time data about the current conditions as the ship sails through the port, which is useful for navigation and operational safety.
• Sitting-bottom ADCP: Best fitted for fixed-point monitoring over longer terms to monitor one particular area of the port. It will continuously provide the same outlook on what the current is at that location. That is also helpful to know in long-term current patterns, and this application finds usefulness in maintenance operations concerning the infrastructure of the port.
• Buoy-mounted ADCP: Useful for areas where fixing on the seabed or on ships is not practical to install. They can float at the water surface and measure around the currents on their surroundings - flexibilities given for measurement spots.

According to Different Frequencies

• The 600kHz ADCP would be quite suitable for water depths up to 70m because it gives rather accurate current measurements in relatively shallow water.
• In places where the depth is about 110m, the ADCP should be 300kHz because it can effectively measure the current at that depth.
• In deeper waters, up to 1000m, a 75kHz ADCP is recommended for reliable current measurement.

There are well-known ADCP brands such as Teledyne RDI, Nortek, and Sontek. However, the Chinese brand China Sonar PandaADCP is also a great option. It is made of all-titanium alloy material and offers an excellent cost-performance ratio. You can visit its website (https://china-sonar.com/) for more information.

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