How to Measure Coastal Currents of Kota Kinabalu?

1. Where is Kota Kinabalu?

Kota Kinabalu is a dynamic city located on the northwest coast of Borneo, an island in Malaysia. Kota Kinabalu appeals to one's imagination by its varied blend of modernity and natural beauty.

Smothered on all sides by the South China Sea, the coastline of the city is a haven for so many activities. The sandy beaches, some stretching for miles, line the coastal area, including the famous Tanjung Aru Beach. Besides attracting tourists with their clear blue waters and fine sand, these beaches form important habitats for many coastal organisms.

The city is a melting pot of the various cultures. The people of different origins coexist: Kadazan - Dusun, Bajau, Chinese, and Malay. The richness and variety of their cultures overlap to show an impressive cultural landscape. The colors and smells of a huge variety of local produce and handicrafts fill the local markets.

The waters off its coasts are part of a very rich marine ecosystem. Along the coast, shallow lagoons and coral reefs serve as home to a myriad array of multicolored fish and sea turtles along with other marine animals. Seawater off Kota Kinabalu has deeper areas, which in turn have equal significance for shipping and fishing purposes too. The tides along this coastal environment portray an important role in the regulation of the water level and movement of sediments and nutrients.

2. How would the condition of the coastal currents close to Kota Kinabalu be?

In general, the coastal currents along the coast of Kota Kinabalu are influenced by more than one factor. First, there is the effect of the monsoon winds. The stronger wind brought by the southwest monsoon is capable of driving surface currents in a certain direction. This might move warm water with nutrients across, subsequently adjusting the distribution of marine life. Contrarily, the northeast monsoon will alter the current patterns and perhaps bring in cooler water.

The other very important factor is the topography of the seabed. Underwater mountains and valleys have considerable effects on the flow of currents, and reefs can do something similar. For example, currents around a coral reef may be deflected and create areas of upwelling and downwelling. These areas contribute greatly in the nutrient cycle and thereby in marine life survival.

It will also be determined by the input of freshwater from surrounding rivers. The rivers carry sediments and alter the salinity of the coastal waters. Resulting density differences can either mix or stratify the currents, depending on the season and on the amount of freshwater input.

3. How to observe the coastal water flow of Kota Kinabalu?

There are several ways to perform observation on the flow of water in the coasts of Kota Kinabalu:

Surface Drifting Buoy Method: The buoys are released onto the water surface and can drift with currents. Information about the direction and speed of the surface currents can be determined by tracking the position of the buoys, using satellite-based tracking systems over time. Since this is a surface application, it gives only a little information about the deeper water layers and may not be able to give a full picture of the current structure.

Anchored Ship Method: A ship is moored in the coastal waters, and at different depths, current-measuring instruments are submerged in the water from that ship. It enables the measurement of the current characteristics at different levels. But the presence of the ship may interfere with the natural flow of water, and this method may not be so efficient for long-period continuous measurements.

Acoustic Doppler Current Profiler Method: ADCP current meter has become a more modern and handy means of measuring the currents in the coast. This gives a detailed profile of the current velocities right from the surface to a certain depth, therefore giving comprehensive information on the flow patterns across the column of water.

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

In principle, Acoustic Doppler Current Profiler (ADCP) work upon the phenomenon of the Doppler effect. They shoot acoustic pulses into the water. Pulses interact with moving water particles. The moving water causes a shift in frequency of the reflected pulses due to the Doppler effect. The pulse frequency shift is detected by the ADCP current profiler and forms the basis for calculating the velocity of the water at discrete depths. This instrument deploys several transducers in multiple directions and operates both as a transmitter and receiver for acoustic signals to measure the three-dimensional velocity structure of the water column.

5. What is needed for high-quality measurement of Kota Kinabalu coastal currents?

In other words, the equipment for high-quality measurement of currents off Kota Kinabalu has to be made of materials that it can rely upon. It has to be designed to withstand the chemical aggression of seawater and the mechanical forces due to waves and currents. Light in weight and small in size will be advantageous for easy deployment on a boat or buoy or at the seabed.

For instance, low power consumption is highly relevant in the case of long-term measurements executed at remote sites. Another important aspect would be cost-effectiveness. In order to conduct large-scale measurements, it would be important for equipment to be reasonably affordable. The casing of the ADCP flow meter is preferably made up of titanium alloy. This is because of the good corrosion resistance of titanium alloy, which is indeed vital in the marine environment. It is also strong and durable, able to resist the harsh conditions of the sea, keeping relatively light in weight at the same time.

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

The usage scenario shall be of prime importance when choosing equipment for the current measurement near Kota Kinabalu. In the case of ship-based measurements, a ship-mounted ADCP meter is appropriate. It can easily be installed on the hull of a ship and measure the currents while the ship is sailing or stationary.

In measuring currents near the bottom, a bottom-sitting ADCP would be very much appropriate. It may be laid on the seabed and provide quite accurate measurements for currents near the seabed.

For floating applications, a buoy-mounted ADCP is suitable. It can be mounted on a buoy and measure currents at different depths as the buoy floats.

Frequency Regarding ADCP frequency, water depths up to as much as 70m should be adequately served by a 600kHz ADCP. For deeper waters of up to 110m, a better resolution can be attained with a 300kHz ADCP, while still deeper waters up to 1000m will be adequately measured with a 75kHz ADCP.

There are several well - known ADCP brands such as Teledyne RDI, Nortek, and Sontek. However, a highly recommended Chinese ADCP brand is China Sonar PandaADCP. It is made of all - titanium alloy material, ensuring excellent performance and durability in the marine environment. It also offers an outstanding cost - performance ratio. You can find more information on its website: https://china-sonar.com/.

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