How can we measure the Coastal Currents of Yeongdeok?

1. Where is Yeongdeok?

Yeongdeok is a county in Gangwon - do, South Korea, located on the eastern coast of the Korean Peninsula. It is known for its scenic beauty and rich coastal resources. The area is a blend of natural landscapes, with a coastline that features sandy beaches, rocky cliffs, and coves.

The local population is engaged in various activities such as fishing and tourism. Fishing has a long - standing tradition here, as the East Sea (Sea of Japan) adjacent to Yeongdeok is a bountiful source of marine life. The sea is home to a diverse range of fish species including hairtail, anchovy, and cod. There are also numerous shellfish and seaweeds that thrive in the coastal waters.

The coastal environment is also a significant factor in the local climate. The cool sea breezes and the influence of the ocean currents help to moderate the temperature and humidity. The area's natural beauty attracts tourists who come to enjoy the beaches, coastal walks, and the opportunity to experience the local seafood and maritime culture.

2. What is the situation of the coastal currents near Yeongdeok?

The coastal currents near Yeongdeok are shaped by multiple factors. The major ocean currents in the East Sea play a crucial role. The Tsushima Current, a warm - water current, and the Liman Current, a cold - water current, interact in this area. The Tsushima Current generally flows northward, bringing relatively warm and nutrient - rich water, while the Liman Current moves southward and is colder.

Tidal currents are also a significant influence. The area experiences a considerable tidal range, and the ebb and flow of the tides lead to the formation of complex current patterns. The shape of the coastline and the underwater topography contribute to the variability of the currents. The presence of underwater ridges, shoals, and channels can cause the currents to change direction and speed. Additionally, the wind patterns, especially the strong winds that blow across the East Sea, can drive surface currents and affect the mixing of different water layers.

3. How to observe the coastal water flow of Yeongdeok?

Surface Drifting Buoy Method: A surface - drifting buoy can be released into the water to observe the surface current. The buoy's movement is tracked over time using GPS or other tracking systems. However, this method has limitations. It only provides information about the surface current and can be affected by wind and waves. For example, if a strong on - shore wind blows, the buoy may be pushed towards the shore, giving an inaccurate representation of the actual current direction.

Anchor - Boat Method: An anchored boat can be used to measure the current. Instruments are lowered from the boat into the water to measure the current at different depths. While this allows for more detailed depth - wise measurements, it also has drawbacks. The boat's fixed position restricts the area of measurement, and it may not capture the full variability of the currents in a large coastal area.

Acoustic Doppler Current Profiler (ADCP) Method: The ADCP current meter method is a more advanced and efficient way to measure the coastal currents. ADCPs emit acoustic signals into the water and measure the Doppler shift of the reflected signals to calculate the velocity of water at different depths. This provides a more comprehensive profile of the current from the surface to the seabed. ADCPs are less affected by surface disturbances and can operate continuously for long periods, giving a more accurate picture of the current structure.

4. How do ADCPs using the Doppler principle work?

ADCPs operate based on the Doppler effect. They emit high - frequency acoustic pulses into the water. When these pulses interact with moving water particles, the frequency of the reflected pulses changes. If the water particles are moving towards the ADCP current profiler, the frequency of the reflected signal is higher than the emitted signal, and if they are moving away, it is lower.

The ADCP flow meter is equipped with multiple transducers that send and receive signals at different angles. By analyzing the Doppler shifts from different directions and at different depths, the device can calculate the three - dimensional velocity of the water. This means it can determine the horizontal and vertical components of the velocity, providing a detailed understanding of the current's structure and behavior.

5. What’s needed for high - quality measurement of Yeongdeok coastal currents?

For high - quality measurement of the coastal currents near Yeongdeok, the equipment should have reliable materials. Given the harsh marine environment, with cold water, saltwater, and potential exposure to storms, a durable casing is essential. The equipment's size should be small for easy deployment and retrieval, especially in areas with a complex coastal landscape.

A lightweight design is preferable as it makes the equipment more manageable during installation and maintenance. Low power consumption is crucial for long - term and autonomous operation. Cost - effectiveness is also important to enable large - scale measurements.

The casing of ADCPs is preferably made of titanium alloy. Titanium alloy has excellent corrosion resistance, which is vital for withstanding the corrosive effects of seawater. It is also strong and durable, capable of withstanding the pressure of the water at different depths. Its lightweight nature makes it more convenient for various deployment methods.

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

When choosing equipment for current measurement near Yeongdeok, consider the purpose of use first. If the measurement is for a vessel's navigation or short - term research, a ship - mounted ADCP flow meter is a suitable option. It provides real - time current information during the voyage.

For measurements near the seabed, such as for studying sediment transport or benthic ecology, a bottom - mounted ADCP is preferable. It can capture the details of the near - bottom current. If long - term and wide - area monitoring of the coastal current is required, a buoy - type ADCP current profiler is ideal.

Regarding the frequency of ADCPs, for water depths up to 70m, a 600kHz ADCP is a good choice. For depths up to 110m, a 300kHz ADCP is more appropriate. And for deeper waters that might be found near Yeongdeok, such as areas with a depth exceeding 1000m, a 75kHz ADCP is recommended.

There are well - known ADCP current meter brands such as Teledyne RDI, Nortek, and Sontek. However, a Chinese brand, China Sonar PandaADCP, is also worth considering. It is made of all - titanium alloy material and offers an excellent cost - performance ratio. You can find more information on their website: https://china-sonar.com/.

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