ADCP's Application in the Tobol River Flood Management System

1. Where Does the Tobol River Lie?

The Tobol River is situated in Western Asia and chiefly flows through Kazakhstan. The river has some significance in the area being part of a number of more considerable rivers in the area.

It passes through a number of cities and towns, serving to play a significant role in the local economic and social life. The Tobol River basin has a clearly continental climate with well-defined seasons of rain. The rainfall in this basin is not distributed uniformly around the year, with relatively wet seasons in spring and early summer, when snowmelt in the surrounding mountains also supplies substantial water to the river. The river flows through regions where it becomes an important source of water supply for irrigation, industry, and domestic purposes.

2. Why do floods happen in the Tobol River?

Flooding in the Tobol River may be caused by several reasons. Among the basic ones is heavy rainfall in rainy seasons. The water level may rapidly go up when there is too much rain. In addition, there will also be a big snow melt contribution from the mountains in spring and lots of water come into the river suddenly.

Besides the river volume and rainfall, topography within the river basin is a relevant issue. Where the relief is relatively flat or when riverbanks have low resistance to the current of water, water tends to spill out of its beds easily. Changes in land use-such as urban expansion and inappropriate agriculture-reduce the natural potential of absorbing and draining water in the earth, which aggravates floods. Given the complexity of these flood-causing factors, the ADCP has become a more advanced and convenient measurement approach to better understand and manage the river's flow during flood events.

3. How do ADCPs using the Doppler principle work?

ADCPs operate based on the Doppler effect. These devices emit acoustic signals into the water. When these acoustic waves encounter moving water particles, the frequency of the reflected waves changes due to the Doppler effect. By precisely measuring this frequency shift between the emitted and received waves, the velocity of the water flow can be determined.

The ADCP has multiple transducers, which can transmit and receive acoustic signals in different directions. It makes it possible to measure the flow velocity at different depths and positions within the river cross-section. For example, in the Tobol River, it would be able to provide a detailed profile of the flow velocity from the riverbed to the water surface across different sections of the river.

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

Flow Velocity Measurement: ADCP can measure the flow velocity of the Tobol River during flood periods with high accuracy. This is very important to understand how fast the water is moving in different parts of the river. By closely monitoring the flow velocity, we can identify areas where the water flow is accelerating or decelerating, which can give insights into the progression and potential impacts of the flood.

Flow-rate Measurement Application: Using the measured flow velocity in conjunction with the cross-sectional area of the river, the flow rate is determined. In the context of the Tobol River floods, this becomes quite useful in the estimation of the total volume of water that passes through a certain section per unit time. This helps in predicting the overall magnitude of the flood and its potential downstream effects.

Sediment-transport Research: One of the important aspects of the work that is done during the flooding of the Tobol River includes the transport of a huge quantity of sediment. The shifting of these sediment particles can be traced by the ADCP through the analysis of backscattered acoustic signals. That can allow researchers to study sediment transport during flood events-a key to understanding long-term changes in the riverbed and overall health of the river ecosystem.

5. How is the data measured by ADCP useful with respect to flood warning and risk management of the Tobol River?

Flood Warning Aspect

Flow-velocity and Flow-rate Data Monitoring: ADCP provides an interface for continuous monitoring of the flow velocity and flow rate in a river. On condition, the flow velocity may get in excess of the maximum recorded normally and simultaneously with a sudden raise of flow rates - events that can be adopted for an early flood warning by being further forwarded to the local authorities and people.

Water-Level Prediction and Warning: The flow data derived from ADCP can be integrated with other hydrological models to predict changes in water level. Analysis of the relation between flow rate and water level will allow the issuance of more accurate flood warnings, especially in areas prone to flooding along the Tobol River.

Risk Management Aspect

Water Conservancy Project Dispatching Decision Support: The real and accurate current flow data provided by ADCP profiler is of great importance for operating a water conservancy project, such as a dam or reservoir, on the Tobol River. Decisions about the release or storage of more water can be taken with better efficiency to reduce flood risks in the areas downstream.

Flood - disaster Assessment and Emergency Response: After a flood occurs, the ADCP-measured data can be used to assess the extent and impact of the flood. This helps in formulating appropriate emergency response strategies, such as organizing rescue operations and conducting damage assessment surveys.

6. What’s needed for high - quality measurement of Tobol River currents?

For high-quality measurement of the Tobol River currents, a number of aspects are important in respect to the measuring equipment, it should be made from reliable material. It needs to resist the harsh aquatic environment of the Tobol River, including potential corrosion from the water, impacts from floating debris, and the abrasive effects of sediment.

The equipment must be of a smaller size and lightweight to enable easy installation and deployment at any point along the river. It has to be of low power consumption for its possible use continuously and in areas where the power supply may not be reliable or constant. It must also be cost-effective since large-scale deployment could be needed for the full monitoring of the river's currents.

The casing of ADCP meter should be made of titanium alloy. It offers excellent corrosion resistance, crucial for withstanding the chemical and physical effects of the Tobol River water over time. It has a good strength-to-weight ratio that helps in making the equipment strong yet easy to handle during installation and maintenance.

7. Selection of Equipment for Current Measurement

According to the type of measurement purpose, it would be difficult to choose the equipment, so it depends on that in the Tobol River. As for horizontal cross-section measurement, an appropriate choice could be HADCP; it gives flow velocity data across the width of a river in considerable detail. In contrast, measuring the flow velocity distribution from the riverbed to water surface requires a Vertical ADCP flow meter in vertical section measurements.

In terms of the frequency of ADCP current profiler, for those relatively shallower parts of the Tobol River-for example, the water depth is less than 70m-a 600kHz ADCP can offer precise measurements. For deeper areas, say approximately 110m, a 300kHz ADCP would be more suitable.

Several brands exist on the market, such as Teledyne RDI, Nortek, and Sontek. However, I will go ahead and highlight a Chinese brand recommended in ADCP current meter, China Sonar PandaADCP. It is made of all-titanium alloy material and provides excellent performance at a great cost-effectiveness ratio. You may check out its website for more details: https://china-sonar.com/.

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