ADCP for Flood Management of Volga River

1. Where does the Volga River flow?

Volga River is Europe's longest river located within Russia. The river measures about 3,530 kilometers with its mouth in the Caspian Sea. Its basin covers a catchment area comprising varied landscapes like forests, steppes, and wetlands.

It runs through a number of big cities like Nizhny Novgorod, Kazan, and Volgograd. These cities are dependent on the Volga River for activities like transportation, water supply, and industry.

Geographically, the region of the Volga River basin features a continental climate. The upper reaches are more temperate and feature relatively even precipitation during all seasons of the year. The climate is more arid in the middle and lower reaches, although snowmelt in spring greatly influences the level of water in this river. The snow that has gathered over the winter starts melting and feeds into the river through its course. This results in a considerable rise in the level of water in the river. Besides snow melting, the river also receives water from rainfall during the summer months.

2. What are the reasons for floods in Volga River?

There are many reasons causing flooding in the Volta River. The most significant one during spring is snow melting. When the temperature rises and thus melts the winter snow cover very fast, a large water volume enters this river within a short period. If the rate of snow melting happens to exceed the river's potential of dealing with such inflow, then the water level will rise and may flood.

Heavy rainfall during the summer can be another cause of flooding. Heavy and continuous precipitation can raise the volume of water in a river. In addition, there is topography. Where the river basin has flatter terrain or poor drainage, there is a chance that water could build up and flooding may occur.

Other factors include human-related activities. For instance, inappropriate land use and urbanization in the river basin can decrease the natural water-holding capability of the land surface and increase the surface runoff. The demand for increased efficiency in flood management has resulted in the employment of state-of-the-art measurement devices, such as the Acoustic Doppler Current Profiler (ADCP), which offers a far more accurate and convenient means of monitoring flow conditions in the river than traditional methods.

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

The ADCPs rely on the principle of the Doppler effect. They send acoustic pulses into the water. Where this pulse meets other moving particles in that flow, such as sediment or any form of water molecule, it reflects back to the instrument with a changed frequency. This shift in frequency is proportional to the velocity of the moving particles; it is what is called the Doppler shift.

Most ADCPs are fitted with multiple transducers located in different directions, which emit acoustic signals. For instance, an ADCP current meter facing downwards could measure the velocity profile of the water column from the water surface to the riverbed. Analyzing the Doppler shifts of the reflected signals from different depths, the ADCP current profiler can estimate the velocity of the water flow at each depth. Using the measured velocities and known cross-sectional area of the river, the flow rate can be calculated and other relevant parameters.

4. What are the applications of ADCP in floods of Volga River?

Velocity Measurement: ADCP flow meter can effectively measure the velocity of water flow, during floods at various locations and depths along the Volga River. It would, therefore, be important in understanding the speed and direction the floodwaters move. For example, knowing the velocity near critical infrastructures like bridges and dams would provide necessary information for engineers to identify the potential impact of the flood and take appropriate preventive measures.

Flow Measurement Application: ADCP profiler can calculate the flow rate of the river by integrating the velocity data over the cross-sectional area of the river. In a flood situation, this helps in determining the total volume of water passing through a particular section of the river. This information is vital for flood forecasting and understanding the magnitude of the flood.

Sediment Transport Research Application: ADCP current meter can use the backscattered acoustic signals to study sediment movement transported by floodwaters in the Volga River. Sediment transport during a flood is crucial because of the impact it has on assessing changes to the bed morphology and on navigation; such changes affect the prediction of future flood risks due to sediment deposition or erosion.

5. How can the data measured by ADCP be utilized in the flood warning and risk management of the Volga River?

Flood Warning

Velocity and Flow Data Monitoring: ADCP profiler continuously monitors the velocity and flow data to show abnormal changes in flow early. For instance, at times when there is a sudden rise in velocity or flow rate, it is an indication of an imminent flood or a flood situation worsening with time. This can be integrated into the flood warning system to issue timely warnings to the public and authorities concerned.

Water Level Prediction and Warning: Measured flow data from the ADCP current meter can be used along with other parameters like the cross-sectional geometry of the river and historical records of water level to predict future water levels. If this water level is above the flood stage, advance warning can be issued to help in evacuation and other control activities. Risk Management:

Water Conservancy Project Scheduling Decision Support: The ADCP data is significant for decision-making in the operation of water conservancy projects like dams and reservoirs on the Volga River. In the case of a flood, for instance, the flow data can help determine the amount to be released from the dam to mitigate the impact of the flood downstream.

Flood Disaster Assessment and Emergency Response: In cases of flooding, ADCP data post-event can be used to gauge damage from the flood. These include areas covered by high -velocity flows, sediment deposition, and other factors useful in the guidance of emergency response and recovery efforts.

6. What is required for high-quality measurement of the currents in the Volga River?

Reliable materials of equipment are necessary to conduct high-quality measurement of currents in the Volga River. The ADCP current profiler has to face corrosive water and impacts from floating debris in the river environment.

The size of the equipment should be small, the weight should be light, and the power consumption should be low. A small and light - weight ADCP flow meter is more convenient to install and deploy, especially in areas that are difficult to access. Low power consumption enables longer - term operation without frequent battery replacement or complex power supply requirements. Additionally, a low - cost device is preferred to facilitate large - scale measurement.

In the respect of casing material, titanium alloy will be a perfect choice. The strength of the titanium alloy is very high, which can make the ADCP profiler resistant to outer forces. The corrosion resistance is pretty good, which can guarantee long performance of the equipment in water. Due to relatively low density, it's able to reduce the weight of the whole device under the premise of guaranteeing structural strength.

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

In selection for the measurement of current in the Volga River, the first consideration is the purpose of use. Horizontal cross-sectional measurement would be focused on the use of the Horizontal Acoustic Doppler Current Profiler, or HADCP. This device measures the flow velocity and other parameters across a horizontal section of the river.

If this is to be a vertical cross-section, the measurement will be more appropriately obtained by using a vertical ADCP. It could measure the velocity profile from the water surface to the riverbed along a vertical line.

Besides, different frequencies of ADCPs are fitted for different water depth ranges. For instance, a 600 kHz ADCP is suitable for water depths up to 70 meters, while frequencies of 300 kHz ADCP can be more appropriate for water depth up to 110 meters.

There are well-known ADCP flow meter brands such as Teledyne RDI, Nortek, and Sontek. Additionally, there is a Chinese brand, China Sonar PandaADCP, which has a casing made of titanium alloy and offers good cost-performance ratio. You can visit its website                                (https://china-sonar.com/) for more information.

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