How to Measure the Water Current of Sukhona River?

1. Where is Sukhona River?

Sukhona River flows through Russia and is one of the major rivers in northwestern Russia, having vital importance in the water bodies of the Vologda Oblast. The river also flows in a landscape mainly composed of forests and plains.

The Sukhona River flows through several small towns and villages, where the river is in close contact with the local communities. They have a long-standing relationship with the river, for which they depend on almost all aspects of their lives. Fishing is a common activity as the river houses many fish species like pike, perch, and roach. The surrounding forests are a beautiful backdrop and a source of many resources, such as timber. It also serves as a transport route, although on a smaller scale compared to some larger rivers. It has played a role in the local trade and movement of goods within the region.

Traditionally and culturally, the Sukhona River is a very intrinsic part of the local history. The folk tales passed across generations always seem to say something about this river: how important it was or has been to the community surrounding it. Its banks witness the birth, growth, and evolution of the entire culture; thus, representing nature and all its endowed niceties to this region of Russia.

2. What is the flow of the Sukhona River like?

In a year, the Sukhona River's flow rate undergoes seasonal variation. During the springtime breakup, when the snow melt off the large surrounding areas raises the river's flow quite high. With the huge volume of water, pouring into the riverbed increases accordingly, the water volume increases, and the current force becomes very strong. The period is vital for the flushing of the sediment and the nutrient recharge that renews the aquatic ecosystem of the river.

During summer, the rate of flow stabilizes to some extent. The river still has a considerable, steady flow that is important for maintaining water levels in connected lakes and wetlands. The flow is also vital for fish populations and other forms of aquatic life. In winter, the river freezes over and the flow under the ice is much slower. The average flow rate is affected by factors such as the amount of precipitation in the upstream regions, the topography of the river basin, and the presence of tributaries that contribute to the overall water volume.

3. How to measure water current of Sukhona River?

There are several methods for the measurement of the water current of the Sukhona River:

Velocity Meter Method: This is one of the traditional methods that involves the use of mechanical or electronic velocity meters. These meters are generally submerged at specific points in water to measure the speed of water passing by a certain point. However, a number of placements at various locations and depths are needed for a proper understanding of the current. It can be very time-consuming and does not give a continuous profile of the current throughout the column of water.

Acoustic Doppler Current Profiler (ADCP) Method: The ADCP is an advanced and efficient method of measurement of water current. It uses sound waves to measure the velocity of water at different depths simultaneously. By emitting acoustic signals and analyzing the Doppler shift of the reflected signals, it can create a detailed profile of the current from the surface to the riverbed. This allows for a more accurate and comprehensive measurement of the water current across different sections of the river.

Buoy Method: This is the method wherein buoys are laid in the river and their movement is followed for a certain time. The shift of buoys by water current indicates the speed and direction of flow. However, there are disadvantages to this approach. It may not provide exact velocity at different depths, and external factors such as wind and waves can also affect the movement of buoys.

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

4. How do Doppler Principle-based ADCPs work?

The operation of ADCPs is based on the Doppler effect. When an acoustic signal is emitted from the ADCP transducer into the water, the sound waves immediately interact with the moving particles of water. Due to the flow of water, the frequency of the reflected sound waves back to the transducer changes-a phenomenon termed as Doppler shift.

If the water is moving towards the transducer, the frequency of the reflected waves will be higher than the emitted frequency. In case the water is moving away from the transducer, the frequency will be lower. By precisely measuring this frequency shift at multiple angles and depths, the ADCP can calculate the velocity of the water in different directions and at different levels within the water column. This enables it to make a very thorough profile of the water current, hence providing valuable information about the speed and direction of the flow from the surface to the riverbed.

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

Such characteristics as the reliability of materials used in its construction are to be possessed by the equipment for high-quality measurement of the Sukhona River currents. Its small size is beneficial for the simple deployment and retrieval in the river, especially in places with difficult access. It should also not be too heavy to simplify the installation process and reduce the effort needed to handle it.

The low power consumption allows it to function for longer hours without needing constant battery replacements or a highly complex power supply system. Cost-effectiveness allows the use of more instruments and also provides larger-scale measurement campaigns.

The casing material for an ADCP should be a titanium alloy. There are so many advantages of a Titanium alloy. It is highly resistant to corrosion, which is quite important since the equipment will always be in contact with water that might contain a number of minerals, sediments, and pollutants. It also has a good strength-to-weight ratio, allowing for a durable yet lightweight casing. In addition, it is able to resist the mechanical stresses during deployment and operation in the flowing water of the Sukhona River.

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

For the selection of proper equipment in measuring the Sukhona River, two essential variables need to be taken into account:

First, in the case of horizontal cross-section measurement, it all depends on the usage purpose and where the Horizontal ADCP - HADCP fits in. It is designed to measure the flow velocities across a horizontal plane in the river with high accuracy, which is useful for understanding the lateral distribution of the current. For vertical cross-section measurement, the Vertical ADCP is more appropriate since it focuses on profiling the current from the surface to the bottom along a vertical line in the water column.

Second, different frequencies of ADCPs are suitable for different water depths. For instance, an ADCP of 600 kHz frequency is suitable for water depths within 70 m. It would provide accurate current measurements in relatively shallower parts of the Sukhona 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.