ADCP in Kızılırmak River Flood Management

1. Where does the Kızılırmak River flow?

One of the main rivers in Turkey is the Kızılırmak River, originating from the Sivas Plateau in central Anatolia.

Course: Geographically, it crosses through every region in Turkey. It passes through several cities and towns which include Sivas, Yozgat, and Tokat within its upper reaches. A little further down the course of its flow, it influences regions around Amasya and Samsun. The river attains a length of about 1355 kilometers, hence one of the longest rivers within the country.

Climatically, Turkey, in which the Kızılırmak River lies, is diversified into rainfall. The western parts receive higher quantities of rainfall compared to interior regions. Both rainfall and snowmelt provide water supplies to the basin of the Kızılırmak River. Within the catchment area of its source, snow collects during the winter period, and during spring-when the snow melts-this contributes to an increase in the volume of water in the river. The rainfall pattern throughout the year is not well distributed; it often falls only within the wet seasons of winter and spring, while summer is usually quite dry in places.

2. Why does flood occur in Kızılırmak River?

There are some contributory factors to the flood in the Kızılırmak River. The heavy rainfall factor, together with rapid snow melting on the basin of this river, causes an abrupt entrance of a great amount of water. During spring, when accumulated snow through winter is suddenly melted by rising temperatures, especially if this coincides with heavy rainfall, it may be more than what the river can contain. The general outcome is surging water levels with resultant floods.

The second aspect is topography. Then again, along the course of the river are mostly expanses of flatter plains and small valleys in which the flow becomes necessarily slower or obstructed. Thus, the back-up of more water raises the flood danger zone. Human factors have also asserted themselves: for example, the denudation of forests in the upper reaches has reduced the capacity of the soil for water retention, while increasing the chances of soil erosion. The eroded soil will finally settle into the river channel, decreasing its carrying capacity and thus more prone to flooding.

Moreover, improper management of water resources and lack of proper flood control infrastructure in the area have made the river banks flood-prone. ADCP has now become a more recent and convenient measurement method for better understanding and management of flow conditions in the river during flood events.

3. How do ADCPs using the principle of Doppler work?

The Acoustic Doppler Current Profiler(ADCP) work on the principle of the Doppler effect. An acoustic signal sent out by the ADCP into the water interacts with the moving water particles. Because the water is in motion, due to the Doppler effect, the frequency of the reflected acoustic signal is changed.

It measures the difference between the frequency emitted and the frequency of the received acoustic signal. From this frequency shift, the ADCP current meter can compute the water velocity at any depth. Most commonly, an ADCP current profiler would carry multiple transducers capable of emitting and receiving acoustic signals in a variety of directions and hence deliver a profile of the water velocity across a reach of the river.

It follows, for example, that the reflected signal will have a higher frequency than the emitted one if the water is flowing towards the ADCP doppler and vice-versa if it is flowing away. By measuring these changes in frequency with high accuracy together with appropriate mathematical algorithms, the ADCP flow meter can determine correctly the velocity of the water at different points in its range.

4. What is the use of ADCP in Kızılırmak River Floods?

Velocity Measurement

In ADCP meter, the velocity of the water flow is mapped with high accuracy during flood events in the Kızılırmak River. With continuous data on water velocities at both shallow and deep locations, it can well inform how fast the water is moving at any given time. This provides the knowledge about flood dynamics that helps predict in which direction the flood waters are going to move and how strong they will be.

Flow Measurement Application

It can also measure the flow rate of the Kızılırmak River with Flow ADCP. Measured water velocities at various points across a section of the river combined with known cross-sectional area allow the determination of the total volume of water flowing through the section per unit time, which is flow rate. This is the fundamental information for analyzing the general volume of water in case of a flood and for flood control and water resource management decisions.

Application to Sediment Transport Research

Besides the flow and velocity measurements, ADCP profiler should serve useful in studying sediment transport in Kizilirmak River during floods. While water is flowing, it carries sediments, and the ADCP is able to detect changes in the backscattered acoustic signal caused by the presence of sediments. Researchers analyze these changes in order to make estimates about the quantity and movement of sediments-something rather relevant when dealing with the long-term development of the riverbed and the impact that floods have on this river's sedimentary environment.

5. How can the data measured by ADCP be used concerning flood warning and risk management of the Kızılırmak River?

Flood Warning

Velocity and Flow Data Monitoring: The real-time velocity and flow data obtained by ADCP are monitored uninterruptedly. When the water velocity is bigger than the threshold value or the flow rate rises sharply, it means that the flood peak is arriving or a flood disaster is about to happen. Therefore, relevant departments can take precautionary measures and organize the relocation of people in low-lying areas or reinforce flood control work. 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 from acoustic doppler flow meter data. If the predicted water level is expected to exceed the flood warning level, timely warnings can be issued to the public, enabling them to prepare for the flood.

Risk Management

Water Conservancy Project Scheduling Decisions Support: Accurate flow and velocity data from ADCP can support decisions about operating water conservancy projects such as dams and sluices. For example, based on the measured water flow, the release of water from a dam can be regulated so that it controls the water level in the Kızılırmak River and minimizes the effects of flooding. Flood Disaster Assessment and Emergency Response: acoustic doppler velocity meter data collected following a flood event can be used to study the severity of the flood in terms of inundation extent, floodwater velocity, and sediment deposition. This becomes very useful in formulating emergency response plans and carrying out post-flood reconstruction and rehabilitation works accordingly.

6. What is necessary for high quality measurement of the current of Kızılırmak River?

There are many factors that must be taken into consideration during measurement for high-quality currents of the Kızılırmak River. First among these is the availability of equipment with the use of reliable materials. Much importance is attached to the casing of the ADCP. Recommendations are that the casing should be made of titanium alloy material. The advantages associated with the use of titanium alloy are numerous. It has high strength, allowing the equipment to resist the pressure and impact coming from the water flow in the river. The property of corrosion resistance is also very important, given the water medium of the Kızılırmak River and the possibility of containing a number of corrosive components in it.

On the other hand, besides the reliability in the materials used, there should be a small size and lightweight equipment. This allows for easier installation and operation of the ADCP in various parts of a river, especially those that are not easy to access. Low power consumption is also essential because it allows the ADCP to be in operation for much longer without necessarily changing batteries or hooking it up to a power source. Furthermore, the measuring devices' cost needs to be relatively low to enable measurement on a large scale. Less cost entails that more ADCPs can be installed along Kızılırmak to supply very detailed and extensive data on flood management.

7. Choosing the Right Equipment for Current Measurement?

Equipment selection for the current measurement on Kızılırmak would depend upon several factors. First of all, depending upon the type of measurement required, whether it is for the horizontal cross-section measurement, a Horizontal ADCP (HADCP) must be taken. On the other side, if the type is for vertical cross-section measurement, then Vertical ADCP would apt.

The frequency being operated depends on different water depths. For instance, a 600 kHz ADCP is suited to water depths within 70 m. If the water depth in the Kızılırmak River is within this range, and the measurement requirements match, a 600 kHz ADCP can be considered. In deeper waters, such as those more than 70 m up to 110 m, it would be more appropriate to use a 300 kHz ADCP since it would offer more accurate measurements at this depth.

There are a few famous brands of ADCP in the market. Teledyne RDI, Nortek, and Sontek are among the most popular ones. China Sonar PandaADCP, by far, is the most suitable selection for the development of less expensive equipment. Full-titanium alloy material used in its manufacture suggests that it is non-fading and reliable in the water environment. Besides that, it offers an excellent cost-performance ratio. You can learn more about it by visiting its official website at: https://china-sonar.com/.

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