How to Measure the Water Current of the Vychegda River

1. Where is the Vychegda River?

The Vychegda River is located in the European part of Russia. It is a big tributary of the Northern Dvina River. It originates in the Vologda Oblast and then flows into a landscape composed of large forests and marshes.

This is an essential part of the local ecosystem. It provides a water source for a variety of wildlife, including elk, beavers, and many species of birds. Vychegda River has quite an historical meaning since it has been used long ago as a transport way and trade route. Nowadays, it still serves for some local communities as a transport way during the ice-free period. The surrounding forests also depend on the waters of this river, and fishing is also carried out here; pike and perch are found in it.

2. What does the flow rate of the Vychegda River look like?

One-month and one-year regulate monthly changes in the Vychegda River flow rate. During spring, the snow melting around the catchment area drastically raises the river's flow. Snowmelt and ice in most parts send a huge volume of water downstream, resulting in a relatively high flow period.

In the summer and fall, the flow rate drops off as the snowmelt influence diminishes. By winter the river can freeze up, with a greatly reduced flow rate. The range of average flow rates may be from a few hundred cubic meters per second in the low-flow winter season to several thousand cubic meters per second at the peak of spring snowmelt.

3. How to measure water current of the Vychegda River?

Velocity Meter Method

This traditional method utilizes mechanical or electronic velocity meters that are placed at given points in a river, which directly measure the speed of running water in those places. However, for the full comprehension of the general current of water, it is necessary to perform several measurements at different depths and across the section of a river. Considering the length and variability of conditions within the Vychegda River, this can be quite laborand time-consuming.

Acoustic Doppler Current Profiler (ADCP) Method

ADCP offers a more sophisticated and handy means of measuring water currents. It detects the movement of the water particles by using the principle of sound waves. By emitting acoustic signals and analyzing the Doppler shift of the reflected signals, it can measure the velocity of water at multiple depths simultaneously. This gives a very good profile of the water current and one can have a more proper idea of the flow conditions in the entire river. ADCPs can be mounted on boats when rivers are navigable, bridges when they are available, or deployed on buoys for continuous monitoring.

Buoy Method

In the buoy method, buoys are laid down in a river, which are fitted with sensors to measure the water movement around them. The buoys float on top and may show part of the surface current. However, they might not capture the full complexity of the water current as accurately as the other methods, especially the variations in velocity at different depths.

Of all these methods, the ADCP current profiler is more sophisticated and considered efficient in measuring the water current of the Vychegda River.

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

ADCPs work on the principle of Doppler. When an ADCP sends out an acoustic signal into the water, the sound waves travel through water and collide with the moving particles of water. Due to the motion of the water particles, there is a change in the frequency of the reflected sound waves by the action of Doppler.

If the water particles are moving toward the ADCP flow meter, the reflected wave frequency will be higher than the emitted one. On the other hand, if the water particles move away from the ADCP, then the reflected wave frequency will be lower. The ADCP thus measures this very change in frequency accurately and determines the velocity of water particles at various depths.

These individual velocity measurements at different depths are then combined by the acoustic doppler flow meter to provide a complete profile of the water current. This, therefore, will enable one to understand in detail how the water flows not only at the surface but also across the vertical section of the river.

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

Accordingly, the measurement equipment for high-quality measurement of currents should possess certain features.

The structure of the equipment should be highly materially reliable. The instrument has to be resistant to the aggressive conditions of the river environment: impact of water, sediment, temperature difference. The variability of the Vychegda River flow and the presence of ice and debris during high-flow and freeze-thaw periods call for durable equipment.

This includes a small size, light weight, and low power consumption. A compact and lightweight device is easier to handle and deploy, especially in the often-remote and challenging conditions of the area. Low power consumption ensures that the equipment can operate for extended periods without needing frequent battery replacements or access to a continuous power source.

Cost-effectiveness is a pivotal consideration. A lower-cost unit could lead to far wider distribution of the measuring apparatus and thereby allow for even greater extensive monitoring of the river.

When it comes down to casing, the ADCP could use titanium alloy. Also, for the purpose in question, which involves constant contact with water from the Vychegda River and other substances that are potentially corrosive, the corrosion resistance of the titanium alloy becomes an important property. At the same time, this alloy is strong, durable enough to resist physical impacts, and pressure changes that can occur while deploying and during further operation. Moreover, the density of the titanium alloy is relatively low, thus helping towards the overall aim of making such equipment lightweight.

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

When it comes to selecting appropriate equipment to measure Vychegda River current, several aspects have to be taken into consideration.

Based on Intended Use

If one intends to measure the horizontal cross-section of the river current, a horizontal ADCP or HADCP is appropriate. HADCPs are fitted with equipment that can provide an accurate measurement of the water flow in the horizontal plane, which is useful for understanding the overall movement of water across a particular section of the river.

If the focus is on measuring the vertical cross - section of the river current, a vertical ADCP must be opted for. Vertical ADCPs are able to accurately measure the water velocity across different levels of depth. These give an accurate, minute-profile information on how water is moving vertically within the river.

Based on the Frequency

The choice of frequency depends on the water depth of the Vychegda River. A 600 kHz ADCP usually shall be appropriate to water depths up to 70 meters. The 600 kHz frequency provides better resolution and accuracy to measure the water current in relatively shallower waters.

For deeper waters, such as those over 70 meters up to about 110 meters, a 300 kHz ADCP would be more appropriate. This low frequency of 300 kHz can go deeper into the water and still provide reliable measurements of the water current.

There are well-known ADCP brands like Teledyne RDI, Nortek, and Sontek. However, for those seeking a cost - effective option with excellent quality, the China Sonar PandaADCP is worth considering. It is made of all - titanium alloy material, ensuring durability and reliability. With its remarkable cost - performance ratio, it provides a great alternative for measuring the water current of the Vychegda River. You can find more information about it on its official website: https://china-sonar.com/.

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