ADCP's application in flood management of Irtysh River

1. Where is the Irtysh River?

The Irtysh River is a significant river that flows from Central Asia. Originating from the Altai Mountain in China and Mongolia, it courses its way through the Kazakhstan and the Russian state before emptying into the Ob River.

Geographically, it passes through a wide range of landscapes. In its upper reaches, it traverses mountainous areas with steep slopes and cold climates. As it moves downstream, it enters into vast plains and steppes. The river is of great importance for the regions it passes through. It provides water for irrigation, industrial use, and domestic water supply. It also supports a diverse range of ecosystems and wildlife habitats.

With respect to climate and rainfall, a continental climate characterizes areas along the Irtysh River. Winters are cold, with heavy snowfall in the upper reaches and mountainous areas. Spring and summer bring on snowmelts and rainfall. The snowmelt from mountains and catchment areas provides a major contribution to the volume of water in the river. Fluctuations in the water level are frequent features because of the combination of snowmelt and rainfall, whereas floods can occur in case of heavy precipitation or rapid snowmelt.

2. What are the causes of flooding along the Irtysh River?

Snowmelt and Heavy Rainfall: The most important reason for this flood is the combination of a sharp snowmelt during spring with heavy rainfall. Large volumes from melting snow in the catchment area and the Altai Mountains, combined with additional rainwater, can suddenly raise the volume of the river. Mountainous terrain in the upper reaches increases the runoff and sends a large amount of water downstream.

Topography: The floodplains and low-lying areas that exist in the course of the river provide space for water to spread and collect. The generally flat plains provide a reduced flow rate for the water, thus giving it a high chance of flooding. At the confluence of the tributaries, additional water during periods of high flow adds to the flood problem.

Human Induced Changes: Deforestation in the catchment area reduces the interception and retention of rain by the forest. Soil erosion results from that, and this eroded soil might deposit in the river, reducing its carrying capacity. The construction of dams and other water-related infrastructure can disrupt the natural pattern of water flow and drainage occasionally, which may increase flood risk in certain areas.

ADCP current meter is an important tool to gain insight into and managing the Irtysh flow during flooding cases.

3. How do ADCPs work that utilize the principle of Doppler?

The operating principle of ADCPs falls on the Doppler principle. A device sends an acoustic signal in the water. The water is flowing; thus, the signal reflected scatters due to moving particles of water. When the acoustic signal is reflected back into the ADCP current profiler, the frequency of the reflected signal is altered due to the occurrence of the Doppler effect.

It measures the frequency difference of the emitted signal and the one received. With this, the ADCP flow meter is able to find the velocity of the water at each additional depth by using an analysis of the Doppler frequency shift. Commonly, such devices would be made with numerous transducers, which have the ability to send and receive acoustic signals in different directions. This enables it to profile the water velocity over a section of the river.

For instance, in the case of water flow towards an ADCP meter, the reflected signal is at a higher frequency than the one emitted. On the other hand, if water flows away from an ADCP profiler, the reflected signal would be at a lower frequency. Precise measurement of this kind of frequency shift, coupled with the right mathematical algorithms, enables accurate determination of the velocity of water at individual points in the measurement range of the ADCP.

4. The applications of ADCP in floods of the Irtysh River.

Measurement of Velocity

During flood events in the Irtysh River, ADCP is crucial for accurately measuring the velocity of the water flow. By continuously monitoring the water velocity at different depths and locations, it provides real - time data on how fast the water is moving. This information is essential for understanding the dynamics of the flood, such as predicting the direction and intensity of the floodwaters' movement.

Flow Measurement Application

Moreover, the ADCP is able to measure flow rates for the Irtysh River. Combining the measured water velocities at different points across a section of the river with the known cross-sectional area of the river will yield the total volume of water flowing through the section per unit time, which constitutes the flow rate. This data is very useful in the assessment of the overall water volume during flood events, and for making decisions concerning flood control and water resource management.

Application in Sediment Transport Research

Apart from flow and velocity measurements, ADCP meter is useful in sediment transport research in the Irtysh River during floods. The moving water carries sediments while it flows. The ADCP can detect changes in the backscattered acoustic signal caused by the presence of sediments. From there, it allows the researchers to estimate the amount of sediments and their movement. Such would be an indispensable factor for understanding the long-term evolution of the riverbed and its sedimentary environment in general and the impact of floods on the river's sedimentary environment.

5. How can the data measured by ADCP be applied to flood warning and risk management of the Irtysh River?

Flood Warning

Velocity and Flow Data Monitoring: Real-time velocity and flow data obtained from ADCP are continuously monitored. If the measured water velocity surpasses a threshold value or the flow rate indicates an abrupt surge, then it may be a signal that either the peak flood is arriving or that there is likely to be flooding. An appropriate authority can take the necessary steps in advance following this early warning; for instance, evacuation of people residing in low-lying areas, reinforcement of flood defenses, and so on.

Water Level Prediction and Warning: Measured flow data correlated with historical data of water level and appropriate hydrological models can be used to predict future water levels using ADCP data. If the predicted water level is likely to exceed the flood warning level, timely warnings can be issued to the public to get ready for the flood.

Risk Management

Water Conservancy Project Scheduling Decision Support: The precise data on flow and velocity from ADCP meter can support decisions related to the operation of water conservancy projects such as dams and sluices. For example, depending on the water flow measured, the release of water in a dam can be regulated to control the water level in the Irtysh River and lessen the impact of floods.

Flood Disaster Assessment and Emergency Response: In cases after a flood event, the data from ADCP profiler are useful in assessing the magnitude of flood - the extent of inundation, the velocity of floodwaters, and sediment deposits. This information becomes necessary at this point for formulating emergency response plans and for carrying out post-flood reconstruction and rehabilitation work.

6. What is necessary for qualitative measurement of currents of the Irtysh River?

Measurement of the Irtysh River currents with high quality requires several factors.

First of all, the equipment applied should be made of reliable material. A great significance here is the casing of the ADCP. The casing is recommended to be made from the titanium alloy. The advantages of this alloy are, it has very high strength, allowing the equipment to sustain the pressure and impact of the water in the river; highly corrosion-resistant, since the environment-the water of the Irtysh River-may contain various corrosive substances.

Besides material reliability, the size and weight of the equipment should be small and light. This makes the installation and operation of ADCP flow meter in various places along the river easier, especially for the most inaccessible areas.

Low power consumption is also an important consideration because longer continuous operations without replacing the batteries or hooking it up to a power source can be achieved. Besides, the equipment cost should be relatively low so large-scale measurement can be done. A lower price will facilitate placing more ADCPs down the Irtysh River and yield more detailed and extensive results for flood management.

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

Where there is a need to select appropriate equipment for the current measurement in the Irtysh River, several considerations must be addressed, If the kind of measurement that one wants to effect is horizontal cross-section measurement, then an HADCP (Horizontal ADCP) should be selected, while if it is for vertical cross-section measurement, a Vertical ADCP current profiler will be appropriate.

In addition, different frequencies are in correspondence to different water depths, a 600 kHz ADCP is suitable for water depths within 70 m. The water depth in the Irtysh River is in this range; if the measurement requirements match, a 600 kHz ADCP can be considered. A 300 kHz ADCP is more suitable for deeper waters, such as waters over 70 m up to 110 m, because it can give a proper measurement at these depths.

Among the well-recognized ADCP current meter brands in the market include Teledyne RDI, Nortek, and Sontek. However, for those in need of budget-friendly ADCPs, there is the China Sonar PandaADCP. It is made of all - titanium alloy material, which ensures its durability and reliability in the water environment. Moreover, it offers an incredible 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.