ADCP's application in flood management of Peace River

1. Where is the Peace River?

It is found on the western side of Canada, having its source in the Rocky Mountains and running through British Columbia and Alberta.

Winding its way through the landscape, it cuts through forests, plains, and valleys along its course. The river is, in fact a major water course for several purposes. It provides water for irrigation of crops, domestic supply to the communities, and is also used for generating hydroelectric power.

The area is continental regarding climate and water sources. During the spring and summer seasons, snowmelt from the Rocky Mountains feeds the river, supplemented by rainfalls. These combinations can bring about variation in water levels. Flooding may occur in areas considered lower lying during heavy snowmelt or intensive rainfall seasons along the course of the river.

2. What are the reasons for floods in the Peace River?

Snowmelt and Heavy Rainfall: Heavy snowmelt during spring and heavy rainfall of the wet season are the major causes of flood in the Peace River. The enormous quantity of water due to the melting of snow in the Rocky Mountains and the catchment area, along with additional rainwater, together can raise the volume of the river very rapidly. The mountainous topography near its source accelerates the runoff process, funneling a large amount of water downstream.

Topography: Floodplains and low-lying areas along the course of the river allow water to spread out and gather in these spots. The nearly flat plains slow down the flow of water, which increases the tendency of water to overflow its banks. The conjunction of several tributaries adds more water at times of high flow and worsens the flooding condition.

Soil and Vegetation Changes: Human - induced or natural changes in the soil and vegetation cover can affect flood patterns. For example, deforestation in the catchment area reduces the ability of the land to absorb and retain water. This leads to increased surface runoff and a more rapid influx of water into the river, increasing the flood risk.

Acoustic Doppler Current Profiler (ADCP) is a tool with considerable value regarding understanding and managing the flow of the Peace River during a flood event.

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

The ADCP works according to the Doppler principle. A device sends an acoustic signal into the water. Due to the fact that the water is flowing, the signal clashes with the moving particles of water. When the acoustic signal is reflected back to the acoustic doppler flow meter , the frequency of the reflected signal changes due to the Doppler effect.

The ADCP measures the differential frequency between the emitted signal and the received signal. From this frequency shift, it calculates the velocity of the water at various depths. These devices commonly have multiple transducers that can emit and receive acoustic signals in different directions. This allows them to create a profile of the water velocity across a section of the river.

For instance, in the case where the water is flowing toward the acoustic doppler velocity meter, the reflected signal will possess a frequency value higher than that of the emitted one. Conversely, if it flows away, then it has a lower frequency. Precise measurements of such frequency changes along with proper mathematical algorithms result in accurate velocities from the ADCP current profiler at different points within its measurement range.

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

4.1 Velocity Measurement

In the case of Peace River, ADCP flow meter helps in the development of a correct velocity during flood events. By continuously monitoring the water velocity across different depths and locations, it provides real-time data regarding how fast the water is moving. The information is essential for understanding the dynamics of the flood regarding the direction in which the floodwaters are likely to move and the intensity of their movement.

4.2 Flow Measurement Application

The ADCP could also measure the flow rate of the Peace River. It is able to combine the measured water velocities at several points across a section of the river with the known cross-sectional area of the river in order to determine the total volume of water that is flowing through the section per unit time (flow rate). This data is crucial for the estimate of the overall volume of water in a flood and for the purposes of decision-making on flood control and management of water resources.

4.3 Application in Sediment Transport Research

Apart from flow and velocity measurements, ADCP profiler has its usefulness in sediment transport research in the Peace River in time of floods. The sediment will be carried along as the water flows. The ADCP meter is sensitive to changes in the backscattered acoustic signal that result from the presence of sediments. Analysis of these changes allows for estimates of quantity and movement of sediments, crucial for understanding the long-term development of the riverbed and how floods affect the sedimentary environment of this river.

5. How can the data measured by ADCP be utilized in the flood warning and risk management of the Peace River?

5.1 Flood Warning

Velocity and Flow Data Monitoring: In real time, the velocity and flow data obtained from ADCP are monitored continuously. If the measured water velocity exceeds the threshold value or the flow rate increases significantly, this may indicate that a flood peak is approaching or there is a potential possibility of a flood. Due to this early warning, the relevant authorities can take necessary precautionary measures such as evacuating people from low-lying areas or strengthening flood defenses.

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

5.2 Risk Management

Support of Water Conservancy Project Scheduling Decisions: The precise flow and velocity data provided by ADCP will help make decisions on the operation of water conservancy projects, such as dams and sluices. In this way, by measuring the water flow, the release of water from a dam can be adjusted to control the water level in the Peace River and minimize the impact of flooding.

Flood Disaster Assessment and Emergency Response: Immediately following a flood event, the ADCP collected data can now be used to quantify the flood magnitude. The information in this regard may encompass the inundation extent, floodwater velocity, and the sediment deposition. This will also provide the necessary information in formulating emergency response plans, as well as in carrying out post-flood reconstruction and rehabilitation work.

6. What is required to measure the currents of the Peace River with high quality?

In measuring the currents of Peace River with high quality, many issues must be considered. First of all, the employed instruments should be manufactured from reliable materials. In this regard, the casing of the ADCP is very important. It is preferable that the casing is manufactured from titanium alloy. The high strength of the titanium alloy will enable the equipment to bear the pressure and impact of the flowing water in the river. Besides, it is highly resistant to corrosion, which will be necessary considering the water environment of Peace River, which may contain various corrosive substances.

Besides material reliability, the size and weight of the equipment should be small and light. The ADCP, therefore, can easily be installed and operational at varying sites along a river, especially where access may be difficult. Low power consumption is also essential for longer periods of continuous operation without necessarily changing the batteries or hooking up to a power source. Moreover, the equipment cost must be relatively low to accommodate large - scale measurement. Thus, lower cost will imply more ADCPs' deployments on the Peace River, more complete, and more comprehensive data for flood control management.

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

When choosing the appropriate equipment for the current measurement in the Peace River, several aspects need to be considered. First, according to different types of measurements, when it is on horizontal cross-section measurement, a Horizontal ADCP (HADCP) shall be selected; and if it falls under vertical cross-section measurement, then Vertical ADCP shall be opted.

Secondly, different frequencies shall be suitable for different water depths. As an example, a 600 kHz ADCP shall be appropriate for water depths within 70 m. In cases where the water depth in the Peace River is within this range and the measurement requirements are appropriate, then the choice of a 600 kHz ADCP can be considered. Where the water is deeper, say over 70 m to a maximum of 110 m, then a 300 kHz ADCP is better because it can measure in such depth with higher accuracy.

There are several well - known ADCP brands in the market, such as Teledyne RDI, Nortek, and Sontek. However, for those looking for a cost - effective option, the China Sonar PandaADCP is a great choice. 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 get more details about it from its official website: (https://china-sonar.com/).

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