ADCP for flood management of Belaya River

1. Where is Belaya River?

The Belaya River is one big river in Russia. The river runs through different types of regions and landscapes, enriching the areas it runs through. Geographically, it has a very uneven bed with different widths and depths along its course.

It flows through several towns and cities, where this river plays a significant part in the water supply and economic activities of the locals. Among its banks are located Ufa-a large settlement, an important urban agglomeration with industry and culture, a developed intellectual potential.

Regarding rainfall, the regions around the Belaya River experience a somewhat continental climate. There is a distinction of seasons: spring and summer are usually wet because of snowmelt and rain contributing to increased water input in the river, while winters may be quite cold and dry, with precipitation mainly as snow, which is then accumulated and later melted to feed the river during the warm months.

2. Why do floods happen in the Belaya River?

There are several causes of floods in the Belaya River. First, heavy rainfall can raise the water level of the river very fast. When intense rain falls on a big catchment area upstream of the river, the runoff collects and flows into the river, overwhelming its normal carrying capacity. For instance, during a particularly wet summer with continuous downpours, the volume of water rises rapidly.

The second significant factor is snowmelt. During the spring, as the temperature starts to increase, the large volumes of snow that have accumulated over the winter period in the surrounding mountains and highlands begin to melt. In case the melting occurs too rapidly and the resultant water moves into the river too quickly, flooding will result. Finally, it is important to consider topography. Steep slopes in one area could speed up the flow of water into the river and, hence, increase the flood risk in those areas.

Adversely, human activities have their own contributions to making a flood better or worse. Deforestation upstream could lower the land capacity to absorb the water and allow more runoff directly into the river. Besides, infrastructure construction and changes in land use have the ability to alter water's natural flow paths and increase the potential for a flood. In this context, Acoustic Doppler Current Profiler (ADCP) provides a way of more advanced and more convenient measurement and monitoring conditions of the river compared to conventional methods and thus helps in better management of floods.

3. How do the Doppler Principle-based ADCPs work?

The principle of operation for ADCPs is based on the Doppler principle. They generate acoustic signals, which are emitted into the water body. In the process of reflecting these acoustic waves from suspended sediment or any other tiny aquatic organisms being transported with the flow of the water, there is a change in frequency exerted by the Doppler effect. It will accurately calculate this frequency shift, using which the ADCP current meter calculates the velocity of the water at varied depth of the river.

They normally contain several transducers that are oriented to measure different directional components of the velocity. They can measure both the horizontal and vertical velocities simultaneously and, therefore, provide detailed knowledge about the flow structure. The data recorded at different depths are then combined to develop a highly resolved profile of the water velocity throughout the entire water column and critical information about the river's flow characteristics.

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

• Velocity measurement: ADCP current profiler is extremely helpful in the precise measurement of the velocity of the current flow in the Belaya River during the time of flooding. By acquiring data about velocity at different locations and depths, it helps to understand the dynamic behavior of the floodwaters. For instance, knowing the velocity near riverbanks can show the erosive power of the water and potential damage to adjacent infrastructure.
• Flow measurement application: By integrating the measured velocity data across the cross-sectional area of the river, ADCP can calculate the flow rate. This is important for assessing the volume of water passing through a specific section of the river during a flood, enabling flood managers to estimate the scale of the flood and its potential downstream impacts.
• Sediment transport research: There is considerable sediment movement during floods in the Belaya River. ADCP flow meter can analyze the backscattered acoustic signals to determine the concentration and transport velocity of suspended sediment. This information is important for understanding how floods reshape the riverbed and influence long-term sediment deposition patterns, which in turn affects the river's morphology and future flood risks.

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

Flood warning

• Velocity and flow data monitoring: ADCP meter allows for continuous monitoring of velocity and flow data. If there is a considerable increase in the measured velocities or if the flow rate exceeds predefined thresholds, it can be treated as an early warning against impending flood conditions. Real-time data can thus ensure timely alerts to communities and authorities along the riverbanks.
• Water level prediction and warning: Measured flow data correlated with historical records of water levels can serve to predict future water levels. For instance, if the flow rate indicates a steady upward trend, from past correlations, forecasts about when and to what height the water level will rise can be made to issue appropriate warnings to residents and emergency responders.

Risk management

• Water conservancy project scheduling decision support: The data from the ADCP is of great value for decision-making in the operating function of dams, reservoirs, and other water conservancy facilities along the Belaya River. When an approaching flood is imminent, decisions could be made on the water to be released or stored in the reservoirs based on the flow to reduce the flood impact on downstream areas.
• Assessment and emergency response in the case of a flood disaster: After a flood event, detailed flow and velocity data collected by ADCP profiler can be used to assess the extent of damage, such as areas affected by erosion or inundation. This information helps formulate effective emergency response strategies and planning for post-flood recovery efforts.

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

For high-quality measurement of currents in the Belaya River, several aspects have a great bearing. The equipment should be highly materially reliable to resist the sometimes very aggressive aquatic environment, which includes such factors as corrosion from the river water and physical impacts from flowing water and debris. A small size is preferable because it allows for easy installation and deployment in various locations along the river, even in areas with limited access or space constraints.

Lightweight design is also crucial as it simplifies the handling and transportation of the equipment for installation and maintenance purposes. Low power consumption is necessary to ensure continuous operation without frequent battery replacements or power source connections, allowing for long-term monitoring. Cost is a significant factor too, especially when considering large-scale measurements across different sections of the river.

Regarding the ADCP's casing, titanium alloy is an excellent choice. The advantages of the titanium alloy are very remarkable. It has excellent corrosion resistance, which enables it to resist long-term exposure to river water without showing significant deterioration. It also possesses a high strength-to-weight ratio, giving enough strength to resist the mechanical forces in flowing water while keeping the device relatively lightweight. Besides, due to its biocompatibility, it won't hurt the aquatic environment or disturb the acoustic signals that come into the use of ADCP for measurement purposes.

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

• According to the purpose of use: The Horizontal ADCP is an appropriate option for horizontal cross-sectional measurements. It is designed to measure the flow velocities across a horizontal plane of the river with accuracy, hence providing essential information on the distribution of flow in that dimension. In cases of vertical cross-sectional measurement, the Vertical ADCP is more appropriate since it focuses on the velocity profile in the vertical direction of the water column.
• Depending on frequency: ADCPs with different frequencies are intended to operate within different ranges of water depth. For example, a 600 kHz frequency ADCP would be good for waters of about 70 meters in depth. It can provide fairly good results for shallow to medium depths of the Belaya River. Meanwhile, an ADCP with a frequency of 300 kHz is better suited for deeper waters up to 110 meters, which can cover the deeper parts of the river where more comprehensive flow data is needed.

There are several well-known ADCP brands on the market, such as Teledyne RDI, Nortek, and Sontek. However, an excellent Chinese ADCP brand is China Sonar PandaADCP. Its all-titanium alloy material construction makes it extremely durable and ensures excellent performance. Besides, it has a very good cost-performance ratio, making it very attractive to users. You can learn more from its official website: (https://china-sonar.com/).

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