How to Measure Salado River Water Current?

1. Where is Salado River?

Salado River is one of the great rivers in South America. It is situated in Argentina and extends for a length of about 650 kilometers. The source of the river is found in the Córdoba Mountains.

The Salado originates from its source and winds through the plains and central valleys in Argentina. Further ahead, it meanders through some important agricultural areas of the country. Its riverbanks house a great amount of vegetation, comprising grasses and shrubs that provide shelters for local wildlife such as rabbits, foxes, and several species of birds.

Other small towns and scattered rural communities line both sides of the Salado River. These communities are dependent on the Salado for irrigation, livestock watering, and small-scale fishing. The flow in the river supports the agricultural productivity of the area by maintaining soil fertility due to its natural flooding and deposition of sediment.

2. What does the flow rate of the Salado River look like?

Salado River flow is very seasonal. During the rainy season, usually from October to March in Argentina, this river increases its flow. An approximate average for this period would be from a few hundred to some thousands of cubic meters per second, depending on the intensity of the rain and the snowmelt from the mountains in its watershed.

During the dry season, the Salado River may become significantly reduced. Under extreme conditions, it partially dries up, leaving only a few isolated pools of water. The flow is also influenced by human activities, especially the extraction of water for irrigation and the building of a number of small dams and reservoirs in its basin. These dams are used for storing water for agriculture and domestic purposes but can disrupt the natural flow patterns of the river at the same time.

The Salado River flow is significant in terms of the ecological and economic well-being of the regions through which it passes. Its waters translate into crops of wheat, corn, and soybeans. The floodplains of this river host all sorts of plant life and animals.

3. How to Measure Water Current of Salado River?

There are several ways of measuring the water current of Salado River. Conventionally, one of the common ways is making use of current meters. These are submerged into the water at some selected points, either mechanical or electronic, and give information on the speed and direction of the flow. Another methodology involves using floats. A float is dropped in the water, and by tracking its movement over a known distance and time an approximation to the surface current speed can be retrieved.

However, a superior efficient and proficient method is employed through using Acoustic Doppler Current Profiler (ADCP). The ADCPs are, in many ways, better as compared to traditional methods.

3.1 How do Doppler Principle ADCPs Work?

ADCP current meter operate on the basis of the Doppler principle. They emit acoustic pulses into the water. At a point where this pulse meets a particle of moving water, due to the Doppler effect, the frequency of the pulse reflected back alters. From this change in frequency, an ADCP current profiler infers an estimate of the velocity of the water at different depths.

These are several transducers of ADCP doppler, sending acoustic signals in different directions. By these transducers, both horizontal and vertical components of water flow can be measured. In that way, one could get three-dimensional mapping of the water current in order to understand better the flow patterns in Salado River.

3.2 What is Needed to Perform High-Quality Measurements of Currents in Salado River?

In the measurement of Salado River currents with ADCP flow meter, equipment characteristics are important in bringing about high-quality measurement. The casing of the ADCP meter should be of a reliable material; one of the best materials is Titanium alloy.

Some of the advantages of the Titanium alloy are its light mass, which is good for easy handling and deployment in mostly remote locations along the Salado River; it also has excellent corrosion resistance. In light of the chemical composition of Salado River water and the sometimes-harsh environmental conditions in Argentina, the corrosion-resistant property of a titanium alloy will ensure that the ADCP provides long-term accuracy and reliability.

Besides, it is expected that the ADCP profiler is of low power consumption and low cost for the extensive measurement along the Salado River. The low-power-consuming ADCP can operate longer and is thus appropriate for continuous monitoring. The cost-effective ADCP can be deployed wider without high financial cost.

3.3 How to Choose the Right Equipment for Current Measurement?

The intended use of the river is perhaps the most important consideration for choosing the proper ADCP for Salado River current measurement. Application wise, if the horizontal flow across a section of the river is being focused upon, then a Horizontal Acoustic Doppler Current Profiler would be appropriate. HADCPs were created with the precision to accurately record or measure the water current for horizontal velocity components.

VADCP is better for vertical flow profile measurements. VADCPs are configured to measure the velocity of the water along a vertical line in the river at varied depths.

In general, shallower reaches of the Salado River may be adequately captured using a 600 kHz ADCP for water depths out to approximately 70 meters. A 300 kHz ADCP may be more appropriate for deeper reaches since they typically provide good measurements at depths of around 110 meters.

There are well - known ADCP brands such as Teledyne RDI, Nortek, and Sontek. However, for a cost - effective option with good quality, China Sonar PandaADCP is worth considering. It is made of all - titanium alloy material and offers an excellent cost - performance ratio. You can find more information on their website: https://china-sonar.com/.

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