How to Measure Water Current of Argun River?

1. Where is Argun River?

The Argun River is an important river in Asia and forms part of the boundary between Russia and China. It rises in the mountains of the Transbaikal region in Russia and flows generally southeastward.

This river crosses various landscapes. For example, in Russia, it cuts across the vast Siberian taiga, rich in wildlife that includes bears, lynxes, and a great number of birds, while its banks support various types of vegetation, depending on the river for its survival. In China, the parts that are flown by this river have unique geographical features, and it supplies much-needed water for these ecosystems.

The Argun River is important for the communities along its banks. In both countries, it has been used in the past for fishing and as a means of transportation. The local people also relate to the river culturally. In Russian and Chinese border regions, it belongs to the local identity and history. Stories and traditions passed through generations involve the waters of this river.

2. What is the flow rate of the Argun river?

The flow rate of the Argun River varies seasonally. With the snowmelt off the surrounding mountains, heavy increases in flow occur in the spring. The water level rises, and the current becomes quite strong. It is during this period when the transport of sediments and nutrients downstream plays an important role in enriching the floodplains of the river and the ecosystems surrounding it.

During the summer, the flow rate is somewhat stabilized. However, it still provides a regular flow of water for the diverse uses of the local populations and the environment. Rainfall in the catchment area further sustains the flow. In the fall and winter, the flow rate is lower. The average flow rate is related to a number of factors such as the amount of snowfall in the upstream regions, the topography of the river basin with respect to how water is collected and drained, and the pattern of water utilization by the local communities of both Russia and China.

3. How to measure water current of Argun River?

There are several ways to measure the water current of the Argun River:

Method of Velocity Meter

Traditional techniques make use of mechanical or electronic velocity meters. Meters are placed at chosen points in the water to measure the speed of the water passing by them. However, in order to obtain a comprehensive understanding of the current, several placements at different locations and depths are required. This is very time-consuming and cannot guarantee a continuous profile of the current throughout the water column.

Acoustic Doppler Current Profiler (ADCP) Method

The ADCP method is a more advanced, efficient way of measuring water current. It uses sound waves to measure simultaneously the velocity of water at different depths. By transmitting acoustic signals and analyzing the Doppler shift of the reflected signals, it could create a detailed profile of the current from the surface down to the riverbed. It, therefore, allows the determination of water current with more accuracy and comprehensive coverage across different sections.

Buoy Method

In this method, the buoys are installed in a river and observed over a certain period. The shifting of the buoys by the water flow provides information about the direction and speed of the movement. However, this may be subject to limitations. Accurate measurements of velocity at different depths may not be possible from it, and external causes like wind and waves may affect the buoyancy.

Among these methods, the ADCP method is more advanced and convenient for measuring the water current of the Argun River.

4. How do ADCPs using the Doppler principle work?

The working of ADCPs is based on the Doppler effect. A sonic signal is emitted from an ADCP transducer into the water, where the sound waves scatter from the moving water particles. Due to the movement of the water, the frequency of the reflected sound waves changes towards the transducer, a phenomenon called the Doppler shift.

If the water is moving towards the transducer, the reflected waves have a higher frequency than the emitted one. If it is moving away, the frequency is lower. By precisely measuring this frequency shift at multiple angles and depths, the ADCP calculates the velocity of the water in various directions and at distinct levels within the water column. This enables it to create a detailed profile of the water current, thus enabling it to provide very useful information about the speed and direction of the flow from the surface to the riverbed.

5. What's needed for high - quality measurement of Argun river currents?

The measuring equipment for high-quality measurement of the Argun River currents should possess certain features: the materials used in its construction need to be reliable for accuracy and consistency in measurement. Small in size, this helps in easier deployment and retrieval in the river at locations that are difficult to access. It should also not be heavy to simplify the installation process and reduce the amount of effort used in handling.

Low power consumption is required for allowing this equipment to operate for several days with batteries without the replacement or in situ complicated supply systems. The other important factor is cost-effectiveness for encouraging more and more users for taking measurements on a larger scale.

Casing: For ADCP, there are several materials for cases available, but among them, titanium alloy works excellently. It is also for many reasons advantageous to use titanium alloy. It is highly resistant to corrosion, which is very important because the equipment is constantly in contact with water that may contain various minerals, sediments, and pollutants. It also has a good strength-to-weight ratio, allowing for a casing that is durable yet lightweight. In addition, it can withstand the mechanical stresses occurring at the time of deployment and operation in the flowing water of the Argun River.

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

While choosing the right equipment for measuring the current of the Argun River, two factors are mainly considered.

Depending on the usage purpose, for horizontal cross - section measurement, the Horizontal ADCP is suitable. It is designed to precisely measure the flow velocities across a horizontal plane in the river, thus enabling one to understand the current's lateral distribution. Vertical cross-section measurement would instead be more appropriate with a Vertical ADCP, as it focuses on the profiling of the current from surface to bottom along a vertical line in the water column.

Secondly, different frequencies of ADCPs are suitable for different water depths. For example, an ADCP with a frequency of 600 kHz is suitable for water depths within 70 m. It can provide accurate current measurements in relatively shallower parts of the Argun River. An ADCP with a frequency of 300 kHz is more appropriate for deeper waters up to 110 m, which can be useful in areas where the river has greater depth.

There are well - known brands of ADCPs such as Teledyne RDI, Nortek, and Sontek. However, for those looking for a cost - effective option with good quality, the China Sonar ​PandaADCP is highly recommended. It is made of all - titanium alloy material and offers an incredible price - performance ratio. You can find out more about it on its website: ​https://china-sonar.com/.

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