How can we measure the Coastal Currents of Yangon?

1. Where is Yangon?

Yangon is the largest city in Myanmar and served as the country's capital in the past. Geographically, it stands in the south of the country, bordering the coast of the Andaman Sea. The city is a bustling metropolis, using a mix of rich history and modern development.

The landscape around Yangon features a mix of urban areas, with skyscrapers and colonial-era buildings, amidst parks and gardens. Culturally, it is the melting pot of different ethnic groups to richly contribute to each other in the vibrant traditions and festivals of the city. The Andaman Sea near Yangon is an important body of water that contributes greatly to the climate and economy in the region.

The coasts contain a variety of habitats. There are sandy beaches, which both tourists and locals favor. Mangrove forests also exist; these are very important to protect the shoreline and serve as a nursery for marine life. Variety species of fish, shellfish, and other aquatic organisms inhabit the sea, thus giving substantial fishing industry support.

2. What is the condition of the coastal currents near Yangon?

A number of factors determine the coastal currents around Yangon. The influence of the monsoon winds is really tremendous. During the southwest monsoon, strong winds are there to drive the surface currents in a particular direction. It is this that accounts for shipping lanes and fishing operations. The tidal forces also form a major determinant. The tides around the Andaman Sea cause the water to rise and fall, resulting in considerable tidal currents.

Salinity and density might be altered by the outflow of rivers and estuaries along the area, affecting current patterns. The shape of the coastline and underwater topography play a vital role. Submerged reefs, sandbars, and channels make currents change direction and speed. It is also the interaction of these coastal currents with the larger oceanic currents that adds to the complexity of the current situation.

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

Surface Drifting Buoy Method: Surface-drifting buoy can be employed to observe the surface current. It is released into the water and tracked over time by GPS or other tracking technologies. However, this is highly limited for it only provides information about the surface current and wind and waves may heavily affect it. For instance, if the buoy is blown by strong wind, it may not represent the actual current direction and speed.

Anchor - Boat Method: For measurement of the current, an anchored boat can be used. The instruments are lowered from the boat into the water to cover the measurement over the entire depth. This again allows for more detailed depthwise measurements. However, the system has certain disadvantages. For one, the boat is fixed, which limits the area of measurement, possibly resulting in failure to capture all the variations in currents over a large coastal area.

The ADCP Method: Today, ADCP current meter is a more advanced and efficient way of measuring coastal currents. It involves emitting an acoustic signal into the water and then calculating the Doppler shift of the reflected signals from the bottom to calculate the velocity of water at different depths. This will provide a more comprehensive profile of the current from the surface to the seabed. Generally, ADCPs are less affected by surface disturbances and can operate continuously over quite long periods.

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

The ADCPs work on the basis of the Doppler effect. They send high-frequency acoustic pulses in the water. When the pulses encounter moving particles of water, the frequency of the reflected pulses shifts. The frequency of the reflected signal will be higher than that emitted by the ADCP current profiler if the water particles are moving towards it, and lower if they are moving away from it.

This ADCP flow meter has many transducers, which send and receive the signals at various angles. They can thus estimate the three-dimensional velocity of water by processing the Doppler shifts that are present in different directions and at different depth levels. This is a way to gauge the horizontal and vertical components of the velocities, thus detailing the structure and behavior of the current.

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

For high - quality measurement of the coastal currents near Yangon, the equipment should have reliable materials. Given the harsh marine environment, with saltwater, high humidity, 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 light design is preferred since it keeps the equipment more handy in installing and maintaining processes. Low power consumption will be very significant, especially for long-term or autonomous operations. Cost-effectiveness shall be ensured to facilitate wide-scale measurement capabilities.

The casing of ADCPs is preferably made of titanium alloy. It will be able to provide good resistance against corrosion, especially for seawater, and be strong enough to bear the water pressure at greater depths. Its lightweight nature makes it more convenient for various deployment methods.

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

The decision on equipment for current measurement near Yangon should first be based on the purpose of use. In case the measurement is for a vessel's navigation or for short-term research, the best available equipment would be the ship-mounted ADCP meter. It provides real-time information on the current during the voyage.

A bottom-mounted ADCP profiler is suitable for measurements near the seabed, such as for sediment transport or benthic ecology. A bottom-mounted ADCP can capture the details of the near-bottom current. Monitoring the coastal current over the long term and for a wide area may be best served by a buoy-type ADCP current meter.

For the frequency of ADCPs, for water depths up to 70m, a 600kHz ADCP may be utilized. In the case of waters up to 110m, a 300kHz ADCP would be more suitable. For deeper waters that could be found around Yangon, those with over 1000m depth, a 75kHz ADCP would be 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.