ADCP's Application in Flood Management of Ishim River

1. Where is Ishim River?

It is located in Kazakhstan and Russia. It constitutes one of the important rivers in this region. The source of this river is traced from the southern part of the Ural Mountains, which flow across vast steppe regions.

It goes through several cities and towns like Astana-a capital of Kazakhstan, though the river is a bit to the north from the city center, which makes it very important for local water supply and transportation. The Ishim River basin has a fully continental climate: winters are cold, and summers are warm. Precipitation is distributed evenly throughout the year, although in spring, snowmelt contributes a large amount of water into the river.

2. What are the Causes of Floods in the Ishim River?

Snowmelt: Snow melting in spring is a major factor observed with many northern rivers. Water from snowmelt greatly contributes to the Ishim River because of its large catchment area. If it gets too warm and the snow starts melting too fast, the quantity of water coming into this river may be more than it is capable of carrying. Then this sudden inflow of much water causes a sudden rise in the level of water and can give rise to floods.

Heavy Rainfall: Heavy rainfall, particularly in the wettest months, also contributes to flooding. If the rain is heavy, the ground becomes saturated, and the excess water then runs off into the river. If this happens when the river is already near its capacity, possibly due to snowmelt or other factors, then a flood can be triggered.

Topography: The generally flat steppe areas that the Ishim River runs through tend to reduce the speed at which water travels. Water can therefore burst its banks more easily and accumulate in low-lying areas. Any obstacles that block the bottom of the river, either naturally or artificially created, such as sediment deposits or improper land use along the banks of the river, impede the movement of water and contribute to flooding conditions.

In this context, the Acoustic Doppler Current Profiler (ADCP) technique offers an advanced and more efficient means of monitoring the flow in the river and flood risk management.

3. How do ADCPs Using the Doppler Principle Work?

ADCPs use the Doppler principle. They send acoustic signals into the water of the Ishim River. These signals interact with moving particles in the water, which may include sediment grains, small aquatic organisms, or other debris moving with the flow. As the acoustic waves strike these moving particles, the frequency of the reflected waves is different from that of the emitted waves. This frequency change, called the Doppler shift, is directly related to the velocity of the moving particles and, by extension, to the velocity of the water flow.

All ADCPs can measure the velocity of the water at different depths and places in the water column by sending out various acoustic beams at different angles and receiving the reflected signals. Advanced signal-processing algorithms allow them to develop a quite detailed velocity profile of water flow. This information will be helpful in understanding the hydrodynamic characteristics of the Ishim River.

4. What are the Applications of ADCP in Floods of Ishim River?

Velocity Measurement: During flood events, ADCP current meter can accurately measure the velocity of the water flow at different points along the Ishim River. This data is vital for assessing the erosive power of the floodwaters. For example, high - velocity flows near riverbanks can indicate areas where erosion is likely to occur. This knowledge allows for the implementation of preventive measures such as bank stabilization or the installation of erosion-control structures.

Flow Measurement Application: ADCP current profiler is able to compute the flow rate of the Ishim River by integrating the measured velocity data over the cross-sectional area of the river. Knowledge of the flow rate is vital in flood management. The authorities can be able to project the quantity of water passing through a given section of the river, which is necessary in making decisions on flood-control structures such as dams and levees.

Sediment Transport Research: The Ishim River carries a certain quantity of sediment. ADCP flow meter can be utilized in the study of the movement of sediment during floods. It is possible to comprehend the impact of floods on the sedimentation and erosion processes in the river by analyzing the dependence of water flow velocity on sediment concentration and the movement pattern. Such information ensures the riverbed is healthy for ecological balance within the river system.

5. How Can ADCP Measured Data Be Applied for Ishim River Flood Warning and Risk Management?

Flood Warning

Velocity and Flow Data Monitoring: Continuous monitoring of water flow velocity and flow rate by using ADCP profiler provides real-time data. When these measured values exceed predefined thresholds, it can trigger an early warning system. For instance, if the flow rate reaches a level at a key monitoring point near a populated area that suggests a high risk of flooding, an alert can be triggered to be sent to local authorities and residents.

Water Level Prediction and Warning: The velocity data derived from ADCP current meter can be integrated into other hydrological models for the prediction of water level. By understanding the relationship between flow velocity and changes in water level, more accurate forecasts are possible about when and by how much the water will rise. This allows for better preparation of measures for flood protection, such as sandbagging or evacuation.

Risk Management

Water Conservancy Project Scheduling Decision Support: The data from ADCP flow meter is useful for decision-making in the operation of water conservancy projects along the Ishim River, like dams and reservoirs. For instance, if the measured flow indicates that a big flood is imminent, the reservoir managers can decide to release water in advance in a controlled manner so as to make room for the oncoming floodwaters. This reduces the risk of overtopping and subsequent damage to water conservancy projects.

Flood Disaster Assessment and Emergency Response: ADCP data can be used for assessing the impact of a flood event after it has happened. This includes the extent of erosion, deposition of sediment in different places, and changes in the morphological features of the channel. This information is greatly useful for formulating effective emergency response and post-disaster recovery plans.

6. What's Required for High-Quality Measurement of Ishim River Currents?

To perform high-quality measurement of currents in the Ishim River, the equipment needs to be made of reliable materials. Since the climate varies, with sediment and debris inside the river, the casing of the ADCP profiler should be tough enough to resist such impacts.

The equipment should be of a relatively small size and lightweight to facilitate easy installation and deployment in different locations along the river. Low power consumption is also essential to ensure continuous operation, especially in remote areas where power supply may be limited. Cost - effectiveness is another important factor, as large-scale deployment of the equipment may be required for comprehensive river monitoring.

The ADCP current meter casing can be made from a titanium alloy. It is a good material with excellent strength and corrosion-resistant properties. Its strength will enable it to resist the mechanical forces exerted by the flowing water, impacts from debris, and other physical stresses. The corrosion-resistance property ensures that the equipment's performance remains stable over time, even in the water-rich environment of the Ishim River.

7. How to Select Appropriate Equipment for Current Measurement?

Based on Usage Purpose: Horizontal ADCP would be used in the case of horizontal cross-section measurement of the river. The velocity distribution across the width of the river can be viewed in great detail. In the case of vertical cross-section measurement, vertical ADCP is more suitable because it can accurately measure the velocity profile in the vertical direction.

Based on Different Frequencies: Different frequencies of ADCP are usable within different water depth ranges. As an example, a 600 kHz frequency ADCP shall be good to go for around 70 m water depth.

It will be relatively accurate for the shallower to moderately deep waters of the Ishim River. The 300 kHz ADCP is best suited for deeper water up to about 110m and should be used in sections of the river where the bottom is deeper. There are well-known ADCP flow meter brands such as Teledyne RDI, Nortek, and Sontek. However, for a more cost-effective option, the China Sonar ​PandaADCP is worth considering. It is made of all-titanium alloy material, offering good durability and an excellent cost-performance ratio. You can find more information about it on its official website: (​https://china-sonar.com/).

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