Application of ADCP to Ocean Current Measurement in Avilés Port

1. Where is Avilés Port?

Avilés is a city situated on the northern coast of Spain. The Avilés Port is an important maritime facility in the region, playing a very important role both in the local and international trade.

Port Scale and Throughput

Avilés has a medium-sized port. Besides general merchandise and some container traffic, it moves bulk cargo such as coal and ores. The volume of cargo handled depends on the season and economic activities in the region. It is an important link to the industries in the area dependent on the importation of raw materials and the exportation of finished products.

Routes and Business: It has an intercontinental structure of shipping routes that link the port with other Atlantic and Mediterranean ports. The dominant sectors of business handled are those involving the shipment of industrial raw materials and products. In the case of fishing and fish -processing industries, too, it is developing, with fishing vessels arriving regularly to deliver their catch. It also participates in cruise activities, although at a relatively lower scale compared to the major ports.

Port Management and Operation

The port is managed by a professional management team that is determined to operate the facility efficiently and safely. The authority controls the berthing of ships, cargo handling procedures, and security. The management systems put in place ensure smooth flow coordination of ships and cargo for timely execution of all activities in the port. The management ensures protection of the environment by reducing pollution and waste emanating from ships calling at the port.

Port Facilities

It is equipped with various facilities, including berths of varying size and depth to accommodate vessels of different sizes. Besides that, it has loading and unloading facilities, which include cranes for bulk and general cargo. Storage facilities also exist in the form of warehouses for dry goods and tanks for liquid cargo. Other services offered by the port include ship repair and maintenance.

Channel and Direct Shipping

The channel of the port is kept at a depth that is appropriate for safe passage by ships. It has direct shipping links with other major ports in the region and beyond. The time and cost of transportation for the goods passing through the port are reduced by the direct shipping links.

2. Why should we measure the ocean currents in the Avilés Port?

Measurement of currents in Avilés Port is necessary from more than one point of view. First, ship navigation needs such data for safety purposes. Currents within the area may alter the speed and direction that ships need to enter and leave the port; if these currents are accurately known, then the captains may know when to decide on avoiding collisions and keeping vessels and port infrastructure safe.

Then again, cargo handling would be affected by a current that might affect the stability of the floating equipment deployed for cargo handling, such as a floating crane or barges; the effect of currents has to be taken into consideration for effective and efficient handling operations with higher accuracy.

It contributes much in the designing of sediment transports, which may result in modifications in channel and berth depths, among other things. The regular measurements of currents establish a database which in turn is necessary for dredging and long-term use of the port.

The ADCP flow meter represents a current measuring method that is in many ways much more advanced and far more convenient. It might give real-time multi-depth currents, data found highly useful for port operations and management.

3. How does it operate using the principle of Doppler on ADCPs?

The working of an ADCP profiler is based on the Doppler principle. These devices emit an acoustic signal into the water. Particles or other substances in contact with this current move together with the current and thereby affect these emitted signals. If these signals come back through interference, then, influenced by the Doppler effect, the reflected signal has changed its frequency. Therefore, according to the shifting, one could compute the water current's speed.

ADCP in Port Ocean Current Measurement

Shipborne ADCP

Shipborne ADCPs are installed on ships. While the ship moves within the port area, the ADCP current profiler sends acoustic pulses downwards and sidewards. In this way, the current velocity at different depths is measured along the track of the ship. Further, in real time, the information is transmitted to the ship's control system for onboard use to make necessary alterations in course and speed.

Fixed ADCP

In Ocean Current Measurement-Port ADCPs are fixed at some specific locations in the port, like on the seabed or on the side of port structures. They monitor the ocean currents continuously in that particular area. The data from fixed ADCPs gives the long-term understanding of the current patterns in the port, which is useful for port planning and infrastructure maintenance.

4. What is necessary to have high-quality measurement of the currents in Avilés port?

The equipment to be used in measuring currents at Avilés port should be manufactured from materials that are reliable. They must be able to put up with the aggressive marine medium, such as seawater corrosion and pressure variations. The desired dimensions are small size, light weight, and low power consumption. A compact size will allow for easier installation in various locations within the port. Low power consumption: This implies less frequent battery replacement, leading to continued operability and elimination of complex powering. Cost-effectiveness is relevant due to its dependency on large-scale deployability measurement devices.

The casing of ADCP meter is preferably made of titanium alloy. The reasons being, first of all, the excellent corrosion resistance which enables it for long-term use in seawater. Besides this, it has a high strength-to-weight ratio that makes it able to bear the high pressure without adding excess weight. In addition, it is biocompatible with minimal impact on the marine environment.

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

Usage Purpose

• Shipborne ADCP: It is used for current measurement while the ship is moving. It delivers real-time data on current conditions while the ship is sailing in the port area and is utilized for navigation and operational safety.
• Sitting-bottom ADCP: Suitable for long-term fixed-point monitoring of a specific area in the port. It provides a constant overview of the current situation at that point, which is advantageous for the study of long-term current patterns and for maintenance purposes of port infrastructures.
• Buoy-mounted ADCP: This is useful in areas that fixed installations on the seabed or aboard ships are difficult to perform. The buoy-mounted ADCP could float on the water surface and make measurements of currents around it, thus offering flexibility in measurement locations.

According to Different Frequencies

• Up to 70m water depth, the ADCP of 600kHz would be good because it provides very good current measurement in relatively shallow water.
• Around 110m, a 300kHz ADCP will be more appropriate since it can effectively measure the current at that depth.
• For 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.