ADCP Application in the Flood Management of Murat River

1. Location of the Murat River

The Murat River is a crucial water body in eastern Turkey and forms one of the main tributaries of the Euphrates River. It originates from the highlands of the region and crosses a large area of Turkey, passing through numerous landforms consisting of mountains, valleys, and plains.

This river passes through several towns and rural areas that rely on its waters for a myriad of uses, such as irrigation in agriculture, which is a very important economic activity in the region, besides meeting the domestic water supply. Regarding precipitation, the Murat River basin has a continental climate with well-defined seasons. It can be cold in winters with snowfall in the upper reaches, and during spring, most of the snowmelt is vital for filling volumes in the catchments. The summer months have some rainfall, though not as steady as the place enjoys in more temperate climates. In general, the contribution of snowmelt and rainfall at any time of the year determines the hydrological characteristics of the river and influences the possibility of flooding.

2. What are the causes of the flood in Murat River?

There are multiple factors contributing to floods in the Murat River. Firstly, heavy snowmelt in spring is a significant cause. As the accumulated snow from the winter months starts to melt rapidly due to rising temperatures, a large amount of water enters the river in a relatively short period. If the river's natural drainage capacity is unable to handle this sudden influx of water, the water level begins to rise, potentially leading to flooding.

Secondly, intense rainfall events during the wetter seasons, especially in summer, can also result in floods. When heavy downpours occur over a large area of the river basin, the additional water flowing into the river can overwhelm its carrying capacity. Additionally, the topography of the region plays a role. This is particularly true in those sections of the river basin area that are more or less flat, with some areas having unaccommodating natural drainage systems; therefore, water often tends to collect rather than run off quickly, adding to the flood situation.

Human factors, too, have their role. Deforestation in the watershed reduces the capacity of the land for water absorption. Instead, more water runs off into the river without infiltrating the ground, thereby raising the volume of water and creating the possibility of flooding. In relation to flood management in the Murat River, the ADCP flow meter has become quite useful and sophisticated compared with conventional measurement methods applied in the past.

3. How do ADCPs using the Doppler principle work?

ADCPs operate based on the Doppler principle. They emit acoustic signals, which are sound waves, into the water. These acoustic waves interact with moving particles in the water such as sediment particles and water molecules that are flowing with the current. When the emitted waves are reflected back by these moving objects, a change in frequency occurs. This change in frequency is known as the Doppler shift.

The magnitude of the Doppler shift depends directly on the velocity of the moving particles. Usually, ADCPs have several transducers that send these acoustic pulses out in different directions. For example, the flow velocity profile from the water surface to the riverbed can be measured with a downward-looking ADCP current profiler. 

The ADCP profiler analyzes Doppler shifts of the reflected signals from different depths in the water column and calculates the velocity of the water flow at every particular depth. From this information regarding velocity and taking into consideration the known cross-sectional area of the river at the measurement location, it is then possible to calculate other important parameters, such as the flow rate of the river.

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

Velocity Measurement: In the case of a flood near the Murat River, Acoustic Doppler Current Profiler (ADCP) can provide an accurate measurement of the velocity of the water flow at different locations and depths. This is essential for knowing the traveling speed of the floodwaters. The velocity will also be related to knowledge near the bridges, along riverbanks with populated areas, or infrastructure so that the relevant authorities can plan the impact of the flood and take timely preventive measures such as strengthening embankments or issuing evacuation warnings when necessary.

Application of Flow Measurement: ADCP current profiler calculates the flow rate of the river by integrating the velocity data over the cross-sectional area of the river. In the event of a flood, an accurate calculation of the flow volume helps in assessing the magnitude of the flood. This permits an assessment of whether the floodwaters will exceed the capacities in flood control structures such as levees, or if significant inundation will occur in nearby areas and thus guides flood mitigation strategies.

Sediment Transport Research Application: During the flood, the floodwater of Murat River will carry a considerable load of sediment. ADCP flow meter, on the other hand, can analyze the backscattered acoustic signals to do research on the transport of these sediment particles. Sediment transport processes during a flood are important for understanding changes to the riverbed, including local areas of deposition or erosion, which is crucial in predicting future flood risks and general river health.

5. How can the ADCP-measured data be used to deal with the flood warning and risk management of Murat River?

Flood Warning

Velocity and Flow Data Monitoring: Continuous monitoring of the velocity and flow data using ADCP profiler will provide early warnings of abnormal changes in the river's flow. For instance, the sudden rise in the velocity of flow of water or sudden serious change in the flow rate might indicate an upcoming flood or acceleration in flooding. This real-time data can be fed into flood warning systems to issue timely warnings to local communities, emergency response teams, and relevant authorities in the areas along the Murat River.

Water Level Prediction and Warning: Flow data measured by the ADCP flow meter can be combined with other factors like the river's cross-sectional geometry and historical water level records for future water level predictions.

If the forecasted water level is predicted to reach or surpass the flood level mark, necessary warnings can be issued with ample time for people to get ready, evacuate if necessary, or take other protective actions.

Risk Management

Water Conservancy Project Scheduling Decision Support: The ADCP data provides substantial input to decision support that deals with the operation of water conservancy projects in the Murat River basin, small dams, or diversion structures. In case the flow measured in the case of a flood is found too high, decisions can be made on adjustments of the gates in such structures to regulate the water flow and avoid causing more damage from the flood downstream.

Flood Disaster Assessment and Emergency Response: The aftermath of a flood can be assessed for the damage it has caused using ADCP data. It helps to identify those areas which have been affected by high-velocity flows, the amount of sediment deposition, and all other information that is important to guide the emergency response related to search and rescue operations and planning post-flood restoration and rehabilitation work.

6. What is required to make high-quality measurement of Murat River currents?

To be able to make a high-quality measurement in the Murat River current, there are a number of aspects that need consideration. First is the reliability in terms of material. The ADCP current profiler should withstand the harsh aquatic environment due to corrosion from river water, impacts from floating debris, or probably abrasive sediment particles.

Besides, smaller in size, lighter in weight, and lower in power consumption are highly desired. A compact and lightweight ADCP flow meter is easy to install and deploy at several locations along the river, access to which may not be easy.

Low power consumption allows for longer continuous operation without frequent battery replacements or complex power supply arrangements, which is advantageous for long-term monitoring. In addition, the cost should be lower to enable wide deployments of the equipment to monitor most of the areas of the river. For the casing material, titanium alloy will be an excellent material.

Titanium alloy has many advantages. It is very strong; thus, the ADCP profiler will be able to bear some forces from outside-for instance, from the water flow, or if it is collided against an object in the river. It also has excellent corrosion resistance, which can ensure the performance and integrity of the equipment during exposure to river water for a long period. Its relatively low density further aids in reducing the overall weight of the device while still keeping its structural stability intact.

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

As in current measurement, equipment should be chosen according to the purpose of the measurement. In horizontal cross-sectional flow measurements, a horizontal acoustic Doppler current profiler (HADCP) would be quite appropriate for the task. Its purpose is the accurate measurement of flow velocities and related parameters across a horizontal section of the river, yielding much-needed information about the lateral flow distribution.

On the other hand, if the measurement is to understand the vertical cross-sectional flow, a vertical ADCP may be more appropriate. It will be able to measure the exact profile of velocity right from the water surface to the riverbed on a vertical line, which helps in the analysis of the changes in the flow along the vertical in the river.

Besides, different frequencies of ADCPs are suitable for different water depth ranges. For instance, the ADCP current profiler with a frequency of 600 kHz is usually suitable for the water depth within 70 meters, while the ADCP flow meter with a frequency of 300 kHz is more suitable for the water depth up to 110 meters. Only by selecting the right frequency in line with the actual water depth of the Murat River is it possible to obtain accurate and reliable results in measurement.

Well-known ADCP current profiler brands in the market include Teledyne RDI, Nortek, and Sontek. There is also a remarkable Chinese ADCP brand: China Sonar PandaADCP. It features an enclosure completely of titanium alloy, which combines durability and excellent performance. What's more, it offers an incredible cost-performance ratio. You can learn more about it on its official website: https://china-sonar.com/.

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