1. Where is the Yenisei River?
The Yenisei River is one of the most important rivers in Russia and the largest river system flowing to the Arctic Ocean. It originates in the Sayan Mountains of southern Siberia.
From a geographical point of view, it cuts across a wide territory, passing through such landscapes as mountainous regions, taiga forests, and great spaces of plains. Coming down to the cities it runs through, one can mention the following: Krasnoyarsk, which is supplied with water for both domestic usage and industrial purposes, including hydroelectric power generation. The Yenisei River serves as an important transportation route to move goods and people around in the area.
Following the course of the Yenisei River, in terms of climate and rainfall, regions all have a continental climate featuring long, cold winters and relatively short, warm summers. Much snow falls in winter, especially in the upper reaches and mountainous area. Snow melting during spring and early summer flows, combined with the rainfall, contributes to the volume of water of the river. A combination of these factors produces wild fluctuations in the water level, and heavy snowmelt or sustained rainfall might produce flooding at any time.
2. Why does flooding occur in the Yenisei River?
Snowmelt and Rainfall: The main reason for the flood is considered to be rapid snowmelting in the spring and heavy rain. This huge volume of water from melting snow in the big catchment area and the additional rainwater may cause a sudden rise in the volume of the river. The mountainous landscape speeds up the runoff process, channeling big amounts of water downstream.
Topography: Existence of floodplains and low-lying regions within the catchments of its course allows the water to spread out and accumulate. Its catchments are relatively flat plains. The water flow velocity is decreased, which indicates a higher possibility of flooding. In addition, convergence of tributaries might bring extra water during high-flow periods.
Man - Induced Changes: Deforestation in the catchment area decreases the interception capability of the forest and the ground through which rainwater falls. Furthermore, it leads to soil erosion, and the eroded soil gets deposited in the river, thus reducing the carriage capability of the river channel. Dams and other hydraulic constructions may, at times, interfere with the natural pattern of water flow and drainage so as to increase the flood hazard in some areas.
The ADCP is therefore an integral means in understanding and managing the flow of the Yenisei River during flood events.
3. How do ADCPs using the Doppler principle work?
ADCPs work on the principle of Doppler. The instrument sends an acoustic signal into the water. Due to the flowing nature of the water, the signal will collide with the moving water particles. When the acoustic signal bounces back to the ADCP, the frequency of the returning signal shifts according to the Doppler effect.
The ADCP detects the differential frequency of the emitted signal and the received signal. Through analysis of this frequency shift, it can compute the water velocity at each depth. Most of these devices are normally fitted with several transducers, which send and receive acoustic signals in different directions. This allows them to present a profile of the water velocity across a section of the river.
For instance, if the water is moving towards the ADCP, then its reflected signal will have a higher frequency from the one emitted. On the contrary, if the water is moving away from the ADCP, then its reflected signal will possess a lower frequency. Precise measurements of such frequency changes, using appropriate mathematical algorithms, enable the ADCP to measure with high accuracy the velocity of water at different points within its measurement range.
4. What are the applications of ADCP in floods of the Yenisei River?
Velocity Measurement
ADCP plays a vital role in the measurement of water flow velocity during flooding events in the Yenisei River. This continuous monitoring of water velocity at varied depths and locations provides real-time data about the water velocity. The information becomes vital in understanding the flood dynamics, such as the direction and intensity of the movement of the flood waters.
Flow Measurement Application
ADCP also measures the flow rate of the Yenisei River. Combining the measured water velocities across the given section of a river with the already known cross-sectional area, the instrument calculates how much water goes through the section per unit time-that is, the flow rate. This data becomes of prime importance for the assessment of a flood event in the scale of the general volume of water and for developing decisions on flood control and water resource management.
Application to Sediment Transport Research
Apart from the measurement of flow and flow velocity, ADCP helps in studying sediment transport in the Yenisei River during floods. While the water flows, it will carry sediments. The ADCP can detect changes in the backscattered acoustic signal caused by the presence of sediments. From these changes, researchers are enabled to estimate quantities and motions of sediments that are necessary for a deeper understanding of the long-term evolution of the riverbed topography and of the effects of floods on the sedimentary environment of the river.
5. How can the data measured by ADCP be used in the flood warning and risk management of the Yenisei River?
Flood Warning
Velocity and Flow Data Monitoring: Real-time velocity and flow data obtained from ADCP will be monitored continuously. If the measured water velocity surpasses any thresholds or if the flow rate has a considerable surge, that can indicate that a flood peak is near or that there will be a flood situation. It then gives enough warning to the relevant authorities for evacuating people in low-lying areas or increasing the strength of flood defenses, respectively.
Water Level Prediction and Warning: Measured flow data correlated with the historic water level data, using appropriate hydrological models, the ADCP data can be used to predict future water levels. In case the predicted water level is expected to rise and 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: Precise flow and velocity data provided by the ADCP may support decision-making on water conservancy project operations concerning dams and sluices. For instance, according to the measurement of water flow, a dam can adjust the release of water to control the water level in the Yenisei River so as to mitigate the effect of floods.
Flood Disaster Evaluation and Emergency Response: The ADCP-collected data after a flood event could be used to evaluate the intensity of the flood event in terms of inundation extent, velocity of the floodwaters, and amount of sediment deposition. This would be very useful information for formulating emergency response plans and for carrying out post-flood reconstruction and rehabilitation work.
6. What is necessary for high-quality measurement of the currents of the Yenisei River?
High-quality measurement of the currents of the Yenisei River will depend on a number of factors. First and foremost, the quality of the equipment used is of reliable material. The casing of the ADCP is most important. The casing should be of titanium alloy. The strength of the titanium alloy is very high, making it very suitable for the equipment to undergo the pressure and impact that may come from the flowing water of the river. It is highly resistant to corrosion, which is important since the Yenisei River water environment will most probably contain quite different corrosive substances.
In addition to material reliability, the size and weight of the equipment should be small and light. This makes it easier to install and operate the ADCP in different locations along the river, especially in areas that are difficult to access. Low power consumption is also crucial as it allows for longer continuous operation without frequent battery replacement or connection to a power source. Moreover, the cost of the equipment should be relatively low to enable large - scale measurement. A lower cost would mean more ADCPs could be deployed down the Yenisei River, therefore offering more complete and detailed records for any flood management.
7. How to Choose the right equipment for current measurement?
When choosing the right equipment for current measurement in the Yenisei River, several aspects need to be taken into account. Firstly, depending on the type of measurement required, if it is for horizontal cross - section measurement, a Horizontal ADCP (HADCP) should be selected. On the other hand, if it is for vertical cross - section measurement, a Vertical ADCP is the appropriate choice.
Second, different frequencies are suitable for different water depths. Such as, the 600 kHz ADCP will be suitable for the water depth within 70 m. If the water depth in the Yenisei River is less than 70 m and it is suitable for the requirement of measurement, the 600 kHz ADCP can be considered. If the waters are quite deep, say from 70 m up to 110 m, the best unit is the 300 kHz ADCP because such depths require more accurate measurements.
Some of the acclaimed brands in the market are Teledyne RDI, Nortek, and Sontek. However, for those on a budget, there is also 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.
| Brand | model |
|---|---|
| Teledyne RDI | Ocean Surveyor ADCP , Pinnacle ADCP , Sentinel V ADCP , Workhorse II Monitor ADCP, Workhorse II Sentinel ADCP, Workhorse II Mariner ADCP, Workhorse Long Ranger ADCP, RiverPro , RiverRay , StreamPro , ChannelMaster etc. |
| NORTEK | Eco, Signature VM Ocean, Signature, AWAC, Aquadopp Profiler etc. |
| SonTek | SonTek-RS5, SonTek-M9, SonTek-SL, SonTek-IQ, etc. |
| China Sonar | PandaADCP-DR-600K, PandaADCP-SC-300K, PandaADCP-DR-75K-PHASED, etc. |
ADCP in the Yenisei River Flood Management