How to Measure Water Current of Indigirka River?

1. Where is Indigirka River?

Indigirka River is one of the important water bodies in the arctic region of Russia. It is located in the northeast part of the land mass known as Siberia. The origin of the river is traced to the Verkhoyansk Range.

From its origin, the Indigirka River flows through the huge and less populated tundra and taiga landscape. Tundra areas along its course come with low - lying vegetation such as mosses, lichens, and small shrubs. While passing through the taiga, the surroundings take the form of coniferous forests dominated by spruce and larch.

The river means a lot to the Arctic because of the special dwelling place it constitutes. Among the fish, there are Arctic chars and nelmas, for example. Its banks are places of dwelling for such mammals as the reindeer, Arctic foxes, and polar bears. The Indigirka is also a migration route for many bird species.

It has played a role in history and the economy of the region. Mostly during summer, when ice conditions are not harsh, it has been used for transport by means of rafts. Traditionally, the river is important to the indigenous communities in the area through fishing and hunting.

2. What is the Flow Rate of the Indigirka River Like?

The flow rate of the Indigirka River has a great seasonal variability. Because of snowmelt and rainfall, in spring and summer, the river flow increases by as many as several times in comparison with the low-water period. During this season, the snow kept in the Verkhoyansk Range and surroundings melts and feeds the river. Thus, during that time, the average flow rate may range from some thousands to tens of thousands cubic meters per second.

It was very small compared to its summer flow due to freezing in winter. The ice cover may reach a large thickness and let a very narrow flow rate continue its flowing beneath it. The presence of ice on the river also has repercussions on the flow characteristics of the river. When spring arrives and it melts, it can also cause sudden changes in water level and flow velocity.

The flow of the Indigirka River itself is crucial in supporting the ecological balance within the Arctic-influenced areas that it crosses. Its waters serve as feeding areas for specific flora and fauna of the tundra and taiga and carry nutrients along with sediments towards its depositing end in the Arctic Ocean.

3. How to Measure Water Current of Indigirka River?

Until now, there are several ways of measuring Indigirka River water current. Some of them are as follows.

Traditional Methods

Float-Based Method: Among the most simplistic conventional methods could be those based on floats. This includes dropping a float into the river and estimating its travel over an already known distance with time. In turn, the speeds of float displacement could give an estimate of the surface current speed by computation. This approach has the disadvantage of providing information only for the surface flow, which might be not an accurate representative for the current at depth. Mechanical Current Meters: These are set in water at selected points. They work on the principle of the speed of water passing through their structure. They can give better readings with higher accuracy for the point at which they are installed, but being troublesome to install, they may not provide a wide view of the entire river current profile.

Advanced Method - Acoustic Doppler Current Profilers (ADCPs)

ADCPs are a more sophisticated and highly effective means of measuring the current in water. The working of an acoustic doppler flow meter using the principle of Doppler is as follows.

3.1 How do ADCPs Using the Doppler Principle Work?

Acoustic Doppler Current Profiler(ADCP) work on the basis of the Doppler effect-a transmitter sends out acoustic pulses into the water. Any time these pulses make contact with moving particles of water, due to the Doppler effect, the frequency of the reflected pulses is shifted in frequency. This change in frequency, or equivalently phase shift, can then be interpreted by the ADCP current profiler to calculate the velocity at each depth of the water.

The ADCP current meter has multiple transducers that send out acoustic signals in different directions. These transducers are capable of measuring both the horizontal and vertical components of the flow of water. This makes it possible to achieve three-dimensional mapping of the current of water, which will be very important in understanding the Indigirka River's complex flow patterns.

3.2 What's Needed for High-Quality Measurement of Indigirka River Currents?

For measuring the quality of currents of the Indigirka River by acoustic doppler velocity meter, the characteristics of the equipment play a great role. The casing of the ADCP should be of reliable material. A very good option is thus given by a titanium alloy.

In this connection, several advantages are associated with the use of a titanium alloy: it is lightweight and, therefore, easy to handle and deploy the ADCP in the often-remote and challenging locations along the Indigirka River. Besides, it has great resistance to corrosion. With the cold climate in consideration, chemical composition, and the harsh Arctic-influenced environment which this Indigirka River water could possess, the corrosion-resistant property of the titanium alloy ensures the long-term accuracy and reliability of the ADCP doppler.

Besides, the ADCP flow meter should have low power consumption and low cost for widespread measurement along the Indigirka River. A low power-consuming ADCP has longer running time and can be suitable for use in continuous monitoring. A cost-effective ADCP allows its installation in large numbers without incurring huge financial costs.

3.3 How to Choose the Right Equipment for Measuring Currents?

One of the most deciding factors for the choice concerning the right ADCP profiler to measure the Indigirka River current is the intended use. In cases where the horizontal flow across a section is of importance, an HADCP would be appropriate. The HADCPs provide quite accurate measurements of the horizontal velocity components of the water current. Vertical Flow Profile Measurement: A VADCP would be better suited for vertical flow profile measurement. VADCPs are configured to measure the velocity of the water at different depths along a vertical line in the river.

Frequency-wise, the 600 kHz ADCP can be used for water depths up to about 70 meters for the shallower parts of the Indigirka River. A 300 kHz ADCP should be better for deeper sections since it provides reliable measurements at depth up to about 110 meters.

There are well - known ADCP meter brands such as Teledyne RDI, Nortek, and Sontek. However, for a cost - effective option with good quality, China Sonar PandaADCP is 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 models.