How to Measure the Water Current of the Athabasca River

1. Where is the Athabasca River?

The Athabasca River is a major river in Alberta, Canada. The source of this river is from the Columbia Icefield in the Rocky Mountains, and the river courses through a number of different terrains that include mountainous regions, boreal forests, and plains.

As it makes its way through Alberta, it is an integral part of the regional water supply. Water is lent for several industrial uses, including the extraction of oil sands in the Athabasca Oil Sands. In other parts, it supplies communities with water and is used for transport: barges and boats navigate and transport goods. Several fish species, including trout and pike, can be found within the Athabasca River. The wildlife that constitutes the living in these riverbanks and wetlands includes moose, beavers, and a number of bird species. These floodplains are crucial for ecological balances, serving as breeding and feeding areas for many species.

2. What is the Flow Rate of the Athabasca River?

The flow rate of the Athabasca River has large seasonal and climatic variations: during the spring and early summer, the snowmelt in the Rocky Mountains greatly raises the river's flow; the melting ice and snow push a large volume of water downstream, resulting in a period of high flow.

In the late summer and fall, the flow rate reduces as the influence of snowmelt diminishes. During winter, the river is grossly reduced, while during periods of extremely cold conditions, it can freeze up. The average flow rates vary from a few cubic meters per second during the winter period of low flow up to several thousand cubic meters per second during the peak spring snowmelt.

3. How to measure water current of the Athabasca River?

Velocity Meter Method

This traditional approach makes use of mechanical or electronic velocity meters. The devices are set up at discrete points along or across the river to measure the local velocities at those points. However, since the water current may not be the same at every depth and part of the river, several measurements are needed for a comprehensive understanding. For a long and variously behaving river like the Athabasca River, this may be labor - intensive and time - consuming.

Acoustic Doppler Current Profiler (ADCP) Method

The ADCP current meter represents a more sophisticated and handy method for the measurement of water currents. It relies on the use of sound waves to detect the movement of water particles. It measures the velocity of water at different depths simultaneously by emitting acoustic signals and analyzing the Doppler shift of the reflected signals. This gives a very detailed profile of the water current, enabling a more accurate assessment of the flow conditions throughout the river. ADCPs can be mounted on boats if the river is navigable, bridges if available, or deployed on buoys for continuous monitoring.

Buoy Method

The buoy method refers to setting buoys in the river with sensors that monitor the lateral movement of water around the buoys. Buoy approaches float on the surface, and some ideas can be obtained about the current on the surface. In contrast to the other methods of discharge determination, they do not have the full characteristic representation of the water current, at least in the explanation of changes in velocity within different strata of depths.

Of all these methods, the ADCP current profiler is more advanced and effective in measuring the water current of the Athabasca River.

4. How do ADCPs using the Doppler principle work?

The ADCPs work on the principle of the Doppler effect. In an ADCP flow meter, the acoustic signal emitted into the water is taken up by the sound waves moving through the water and interacts with the moving particles of water. Due to the motion of the water particles, the frequency of the reflected sound waves changes because of the Doppler effect.

When these water particles move towards the ADCP meter, the reflected wave frequency will be higher than that emitted; on the contrary, in cases when water particles move away from the ADCP, their frequency will be lower. Since it can very accurately measure such a shift in frequency, the ADCP will hence be able to find the velocity of water particles at different levels of depth.

The ADCP meter then sums these velocities measured individually over various water depths to present the detailed profile of the current water. Therefore, the development of complete knowledge on water flow details not only in respect to their surface value but at different vertical sections of a river will be provided.

5. What's needed for high-quality measurement of the Athabasca river currents?

Such measurement of the current in the Athabasca River will require the equipment to have characteristics for high-quality measurement.

The material reliability of the equipment must be high. The equipment will be subjected to a number of vigorous conditions while in the water and sediment and under changing temperature conditions. In the flow variability of the Athabasca River, along with the periods of ice and debris transport during high-flow and freeze-thaw events, equipment must be sturdy.

The size should be small, the weight minimal, and power consumption low. A small and lightweight device is easier to handle and deploy, especially in the remote and challenging conditions of the Canadian wilderness. Low power consumption ensures that the equipment can operate for extended periods without needing frequent battery replacements or access to a continuous power source.

Cost-effectiveness is also a critical factor. A less expensive option makes it possible to deploy the measurement equipment on a wider scale, monitoring more of the river.

In this case, for the casing of the ADCP flow meter, titanium alloy would be a great material to use. Corrosion resistance was another very important reason why the design was to be made out of Titanium alloy, bearing in mind the equipment is always interfacing with water from Athabasca River and with potential corrosive components. Thus, it has strength that will not be defeated by various physical impacts or pressure fluctuations at times of deployment or during its operational process. Moreover, the density of the titanium alloy is relatively low, contributing to the overall goal of keeping the equipment lightweight.

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

When choosing the right equipment for measuring the current of the Athabasca River, several factors need to be considered.

Based on the Purpose of Use

For horizontal cross-section measurements of river current, an HADCP would be the proper fit. HADCPs are designed to give very accurate measurements of the water flow in the horizontal plane and would be useful for the general view of water movement across a certain section of the river.

If the focus is on measurement regarding the vertical cross-section of the river current, a vertical ADCP current profiler should be chosen. Vertical ADCPs will be able to accurately detect the speed of water at various depths and provide an intricate profile of how the water flows vertically inside the river.

Based on Frequency

The choice of frequency depends on the depth of the water in the Athabasca River. For water depths up to 70 meters, a 600 kHz ADCP is usually sufficient. The 600 kHz frequency provides good resolution and accuracy for the measurement of the water current in relatively shallower waters.

For deeper waters, such as those exceeding 70 meters up to around 110 meters, a 300 kHz ADCP is more appropriate. The lower frequency of 300 kHz can penetrate deeper into the water and still provide reliable measurements of the water current.

There are well-known ADCP current meter brands such as Teledyne RDI, Nortek, and Sontek. However, for those seeking a cost - effective option with excellent quality, the China Sonar PandaADCP is worth considering. It is made of all - titanium alloy material, ensuring durability and reliability. With its remarkable cost - performance ratio, it provides a great alternative for measuring the water current of the Athabasca River. 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.