How to estimate the coastal currents of Jinzhou?

1. Where is Jinzhou?

Jinzhou is a coastal city in Liaoning Province, China. The western coast of Liaodong Bay belongs to Jinzhou and is a part of the Bohai Sea. Jinzhou is an ancient city and an important one in that region, with a rich cultural background.

The climate of Jinzhou is a monsoon climate with warm temperatures, and the characteristics include somewhat cold winters and warm summers. The sea wind contributes to equalizing the local climate, which in turn brings moderation, especially during summer. Precipitation in the region is in moderate amount, favorable for vegetation cover by the growth of forests and agricultural crops.

Jinzhou's aquatic area is a high-priority part of its economy, including fisheries, transportation, and ports. Geologically, the sea floor topography around Jinzhou is irregular: shallower waters nearer to shore and deeper water farther away. The physical conditions, such as tidal action, winds, and ocean currents especially from the Bohai Sea, determine the condition of the upper waters.

2. What is the coastal current situation around Jinzhou?

Several factors regulate the coastal currents in the vicinity of Jinzhou. Firstly, the presence of the monsoon climate exerts a huge influence. The southeast monsoon during summer may drive surface waters to act in turning the direction and strength of coastal currents and thus may change fishing and shipping routes. The northwest monsoon in winter alters directions and speeds of the current.

Topography of the sea floor is important. This may be because underwater ridges, troughs, and shoals can cause the water to deflect in different directions and travel at various speeds. Shallow areas would tend to develop more sluggish currents, while stronger and more complicated flows could reside in the deeper areas. For example, the water might speed up over shoals because of the shallower depth, whereas it might get stronger with more intense actions in troughs; the circulation could be more complicated there.

The other important factor is tides. The Bohai Sea normally has a regular rise and fall in the tides, which can create considerable tidal currents. These tidal currents are very strong near estuaries and narrow channels. They play a vital role in the transportation of sediments, nutrients, and marine organisms. It also influences coastal erosion and deposition, further modifying the outline of the coastline and the distribution of marine life.

It also can be further modified by the interaction with the large-scale ocean currents originating from the Bohai Sea and other adjacent areas. The oceanic currents can bring in water masses with different temperatures and salinity, thus affecting local current dynamics. For instance, the intrusions of warmer or colder water masses will change the temperature of the waters in the coastal area, which would provide an impact on both the local marine ecosystem and weather patterns.

3. How to Observe the Coastal Water Flow of Jinzhou?

Accurate measurement of coastal currents is very important in Jinzhou for marine safety, fishery management, and coastal protection. Traditional observation of coastal water flow relies on buoy and current meter, which has been operated for long years. However, these traditional observations have many problems in accuracy and coverage.

Acoustic Doppler Current Profilers have now become a more advanced and convenient way to measure coastal currents. Acoustic Doppler Current Profiler(ADCP) work by using the Doppler principle to measure the velocity of water flow.

3.1 Operating principle of Doppler Principle ADCPs

ADCP current meter emit sound waves into the water. These sound waves scatter off of the suspended sediments and small organisms along with the rest of the moving particles in the water. Since the particles are in motion, the frequency of the reflected sound waves changes. The frequency shift is related to the velocity of the water current.

It sends out and receives sound waves from its transducer array in various directions. The ADCP current profiler estimates the speed and direction of the current at different depths by analyzing the frequency shifts of the reflected waves in multiple directions. In such a way, the three-dimensional structure of the current can be understood.

3.2 What is required for good-quality measurement of Jinzhou coastal currents?

To measure high-quality coastal currents in Jinzhou, many issues have to be put into consideration. First and foremost, the issue of equipment reliability. ADCP doppler should, therefore, be made with materials that can resist the harsh marine environment.

Titanium alloy is an excellent material used for casing in ADCP flow meter. It is highly resistant to corrosion, something important due to the salty water at the coast. The material is resistant to corrosion by seawater and marine organisms and can stand long-term functioning. Besides, titanium alloy is strong and lightweight. It means its strength stands the physical stress in the marine environment, where light weight facilitates manipulation and installation.

In addition to material reliability, other characteristics like small size, low weight, and low power and cost are advantageous. Since a compact and lightweight ADCP meter allows one to transport and deploy it easily to almost any location for measurement, longer operation without frequently changing the batteries or using a large power supply is possible with low power consumption. Cost-effectiveness is an important factor in large-scale deployments that would allow for more extensive monitoring of the coastal area.

3.3 How to Choose the Right Equipment for Current Measurement?

The selection of the right equipment to measure the currents in Jinzhou coastal needs consideration of a number of factors. One of the fundamental factors to consider is the intended usage of the equipment.

The ADCP mounted on a ship would be appropriate for measurements from a vessel in motion. It would deliver current real-time data while the vessel moves along the coast and thus enable the monitoring of current conditions.

The ADCP should be bottom-mounted if the measurement is to be performed at a fixed location on the seabed. It can be installed at a specific point and measure the current at that position over long periods with high stability.

An ADCP buoy-mounted can be used for applications in open water or in areas where a fixed installation is not possible. The current can be measured over a wider area and the data transmitted wirelessly.

Besides, regarding the frequency, the water depth would be related: normally up to 70 meters, a 600 kHz ADCP should do, between 70 to 110 meters, a 300 kHz ADCP would better serve the purpose, and in much deeper waters, up to a depth of 1000 meters, one could consider a 75 kHz ADCP.

When it comes to choosing an ADCP brand, well - known international brands such as Teledyne RDI, Nortek, and Sontek are popular options. However, for those seeking a cost - effective yet high - quality alternative, the ChinaSonar PandaADCP is worth considering. Made entirely of titanium alloy, it combines durability and reliability with an excellent price - performance ratio. You can find more information about it at https://china-sonar.com.

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