How to Measure Water Current of the Dnieper river?

1. Where is the Dnieper?

The Dnieper River is one of the most important waterways in Eastern Europe. It passes through Russia, Belarus, and Ukraine. Originating in the Valdai Hills of Russia, it winds its way south for more than 2,200 kilometers.

The river passes through every imaginable kind of landscape. Coming from the north, the upper course passes through forests and open spaces. The further the river runs, the more it cuts across cities and towns, most of which have prospered through time on its banks. On its banks is the majestic capital of Ukraine, Kyiv. It has played a significant role in history and the development of these regions as well as in the background. Being a very important transport route, trade has been able to take place, which has also fostered cultural exchanges.

The Dnieper is yet another rich source of the ecosystem. In its waters, various species of fish exist, while wetlands and floodplains on the sides host hundreds of birds and other wildlife. On the riverbanks themselves, there's a combination of natural vegetation and agricultural land; this forms a way of irrigation whereby water can be used to grow crops like wheat and sunflowers.

2. What is the Flow Rate of Dnieper?

Flow rate in Dnieper changes according to season and location. During spring, with snow melting in the upper reaches and its tributaries, flow increases by as much as seven times. Then, during this time, the river swells and the current is quite strong. The peak flow in spring is essential since it raises up the low-water level and is necessary for the overall health of the river ecosystem.

During summer, it somewhat stabilizes but is nevertheless at the mercy of precipitation rates and release rates from reservoirs. During autumn and winter, it has a generally lower flow rate. Additionally, the average flow rate can vary along the length of the river. Closer to the source, the upper reaches have a relatively rapid flow because of the steeper gradient. While moving further downstream and reaching the flat regions, the flow becomes slow and the river expands.

The Dnieper River's flow is regulated by human activities as well, associated with the construction of dams and water diversion to irrigation and electricity generation. It might alter natural flow patterns and ecological processes in the river.

3. How to Measure Water Current of the Dnieper?

There are several ways to measure the Dnieper water current.

Traditional Met​hods

Float Method: A very simple traditional method of making rough estimates for the water current of the river is carried out by using a float. Some buoyant object, such as a block of wood or a plastic bottle, is thrown into the river. An approximation of the speed of the surface current can be had by measuring the time taken for the float to travel over a known distance. Therein lays its limitation, because wind, waves, and even the shape of the float will introduce errors, and this method yields information about only what is happening at the surface, not at depth.

 Current Meters: These could also be either mechanical or electrical and are used in the measurement of the velocity of water at one point. The meters are submerged into the water to a certain depth in order to measure the velocity of the water passing through them. Sometimes they can give better information than the float method at a single point in the water column. But they are limited to that depth only without a comprehensive view of the contemporary profile throughout the water column.

Advanced Method - Acoustic Doppler Current Profiler (ADCP)

They are an advanced, more efficient means for measuring the water current of the Dnieper.

3.1 How Do ADCPs Using the Principle of the Doppler Work?

ADCP profiler work on the principle of the Doppler effect. The instrument sends acoustic pulses out into the water. These pulses scatter off suspended particles and other contents in the water, such as sediment, plankton, and small debris. As the water moves, the frequency of the reflected acoustic signals changes. 

This frequency shift is measured by the ADCP meter and converted into the velocity of the water at that depth by using the Doppler formula. Multiple directions and frequencies of pulses are emitted by the ADCP flow meter to create a fine profile of the water current throughout the water column. This provides a more detailed understanding of the internal structure of the current compared with the more traditional measurement techniques, which can measure only at the surface or a single point within the water column.

3.2 What's required for high-quality measurement of Dnieper currents?

For high-quality measurement of the Dnieper currents, the equipment should have very high reliability due to specific climatic conditions and likely events with very high flow may carry water with sediment, and such effect the measuring devices should be able to sustain The equipment shall also not be of heavier weight or bulky one. 

Ease of deployment is particularly important especially in the mostly remote areas along the river or from boats. A design for low power consumption is desirable with the aim of operating the equipment over long periods without having to change batteries or get power supplies constantly. Cost-effectiveness is yet another critical consideration in view of the large-scale or long-term measurements that need to be taken for monitoring the river's dynamics. 

The casing of ADCP doppler made of titanium alloy is very advantageous. Being seriously resistant to corrosion is very important in a water-rich environment like that of Dnieper. Continuous contact with water added to chemicals and sediments can easily corrode other material. The forces of the current and probable impacts from floating logs or other deadwood will also be resisted by the strength and solidity of the titanium alloy. Due to its light weight, installation and transportation are more hassle-free.

3.3 How to choose the right equipment for Current Measurement?

The equipment for measurement of current of Dnieper has to be oriented towards the specific requirements of measurement. 

For Horizontal Measurements: The horizontal ADCP would be used for horizontal measurements across the section of the river. This would give a broad view of current flow in the horizontal plane of vision, useful in understanding the overall flow patterns of the river. This is particularly important in the study of water and sediment motion across the river, where the effect of currents on navigation and nutrient distribution is involved. 

For Vertical Profile Measurements: Vertical ADCP shall be more applicable for the vertical profile measurements of the current. It could provide detailed information on the velocity of water at different depths, especially for studying stratification and mixing of the water column. This is very vital as it drives the distribution of oxygen, temperature, and other properties in water, and in turn, aquatic organisms as well. 

Frequency Selection: For large areas of the Dnieper, which are pretty shallow, an ADCP current profiler of 600 kHz can work well; for greater depths-in this case, up to about 110 meters-the preferred option is the 300 kHz ADCP. In-water depth and resolution on the current profile boil down to frequency selection.

There are well - known ADCP brands such as Teledyne RDI, Nortek, and Sontek. However, for a cost - effective option with good quality, the ChinaSonar PandaADCP is a great choice. It is made of all - titanium alloy, providing durability and resistance to the Dnieper's environment. It also offers an excellent price - performance ratio. You can visit https://china-sonar.com/ for more information. ​

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