How to Measure Water Current of the Guaviare River?

1. Where is the Guaviare River?

The Guaviare River is a well-known water current in Central South America, within the Republic of Colombia. In fact, it comes out from the Macarena Mountains, right in the middle of the country. From there, it initiates a path through thick and well-biodiversified areas that are typical of the jungles of the Colombian Amazonas.

It passes through the territory of many local indigenous groups while flowing. The communities are attached to the river since they have it as a source for fishing, means of transport, and as a supplier of water for them to live. The Guaviare River connects these communities altogether, being very important in matters concerning trade and cultural interchange.

The river also plays a leading role in the general ecosystem of the entire Amazon region. It provides shelter to a diverse type of aquatic life, some species of fish nowhere else found, and other reptiles, amphibians, and mammals. The tropical rainforest surrounding the river is filled with an immense variety of flora and fauna, which the waters nourish. Guaviare and all its tributaries form part of a complex web necessary for the area to maintain ecological balance.

2. What is the flow rate of the Guaviare River like?

The Guaviare River is fed by the seasonality of the Amazon rain essentially; therefore, its flow varies quite a lot during the year. During the rainy season, which generally extends from April to July, it highly increases. Intense rains falling on the Macarena Mountains and the immense catchment area pour large volumes of water into the Guaviare River.

This high-flow period is quite critical to the ecosystems found along this river. It usually helps in washing out the sediments, renews stages, and gives a wide arena for the aquatic organisms to live in. In such periods, the river can swell and may cover a wider area, with the flow rate rising to several thousand cubic meters per second.

The Guaviare River has been in its low flow from August to March. Yet, it is always steady and placid in its flow rate at this period, which is important to all forms of life dependent on the said river. At this time, its flow can have an average of just a few hundred cubic meters per second up to a thousand cubic meters per second.

Navigation on the Guaviare River is also influenced by the volume of water it carries. Larger boats can travel better during its high-flow period, thus making access to remote areas easier and transportation both of goods and people more feasible.

3. How to Measure Water Current of the Guaviare River?

Velocity Meter Method

The old conventional method involves the use of mechanical or electronic velocity meters. These are the devices that are kept at specific points in the river for measuring the speed of water directly at those points. However, it requires careful placement and multiple measurements at different depths and positions in order to get a comprehensive understanding of the overall water current. By nature, the Guaviare River is backwater and mainly inaccessible; hence, this technique can be highly cumbersome and too time-consuming.

Acoustic Doppler Velocity Profiler Method

The ADCP is more sophisticated and handy in determining water currents. It senses the water particles' movement, by means of emitted sound waves. These instruments can measure the speed of water current at several depths simultaneously by applying the principle of emitting acoustic signals and analyzing the Doppler shift of the reflected signals. This represents the form of detailed profile information of the water current by which more accurate assessments of flow conditions in the river can be achieved. Acoustic Doppler Current Profiler(ADCP) may be installed in boats that then travel across the river while taking measurements. They can also be deployed across bridges or attached to buoys for continuous monitoring.

Buoy Method

In the buoy method, buoys provided with sensors that can measure the movement of surrounding water are placed in the river. They float on the surface and can give a certain indication about the current on the surface. However, they may not capture the full complexity of the current water as well as the other methods do, at least concerning variations in velocity at different depths.

Among those, the ADCP stands out as an advanced option to measure the water current of the Guaviare River in a most effective way.

4. How do Doppler Principle-based ADCPs Work?

The general operation of an acoustic doppler current profiler ADCP is based on the principle of frequency shift caused by the Doppler effect. When an ADCP sends its acoustic signal into the water, the sound waves travel through the water and interact with the moving particles of water. Since the movement of the water particles is in motion, the reflected sound waves return to the transmitter at a different frequency due to the Doppler effect.

If the water particles are moving towards the ADCP current meter, then the reflected wave frequency will be higher than the emitted one. On the other hand, if the water particles are moving away from the ADCP flow meter, then the reflected wave will have a lower frequency than that of the emitted wave. Now, by accurately determining this shift of frequency, the ADCP current profiler will determine how much the water particles are moving at different depths.

The ADCP current profiler then takes the individual velocity measurements at a set of depths and combines them into a complete profile of the water current. This gives a highly detailed profile that can provide insight into how water flows, not only at the surface but throughout the vertical section of the river.

5. What is needed to obtain high-quality measurement for the Guaviare River currents?

The following constitute some of the key ways in which high-quality measurement of the currents of the Guaviare River is ensured by the equipment used:.

The equipment to be used should have high material reliability. It should withstand the "harsh" conditions of being in the river: water, sediment, and huge ranges in temperature. For one, the Guaviare River is subject to fluctuating water levels, which may also give the measuring equipment a hard time when debris is being carried along during the wet season.

Second, small size, low mass, and low power are desired. A device which is smaller in size and lighter in weight is easier to handle and deploy, whether on a boat or attached to a buoy. Finally, low power usage ensures that equipment could run for extended lengths of time without needing frequent battery replacement or access to a continuous power supply, which can be crucial in the remote areas along the river.

Cost is another consideration: the lower the cost, the wider its application as measurement equipment, thus wider monitoring of the river.

On the casing of the ADCP current meter, titanium alloy can be found in excellent form. Titanium alloy has several advantages:. It is highly resistant to corrosion, which is quite necessary when dealing with water bodies like that of the Guaviare River, where equipment will always be in contact with water and may come into contact with corrosive substances. Strong and durable, it is able to resist physical impacts and the eventual pressure variation during deployment and operation. In addition, titanium alloy has a relatively low density, which contributes to the general purpose of keeping the equipment lightweight.

6. How to Choose the Right Equipment for Current Measurement?

The appropriate equipment in measuring the current of the Guaviare River depends on several factors.

Based on the Purpose of Use

When the intention is to measure the horizontal cross-section of the current of the river, then such an ADCP is called a HADCP. A HADCP can be designed to make quite accurate measurements in the horizontal plane of the water flow and may be useful for determining the overall movement of the water across any particular section of a river.

The measuring of the river current cross-section vertically will require one to select a vertical ADCP. A vertical ADCP will be able to measure water velocity at different depths with accuracy and provide full detail of the water flow vertically within the river.

Based on Frequency

The selection of the frequency also goes with the depth of the water in the Guaviare River. For shallow depths not in excess of 70 meters, a 600 kHz ADCP is already quite often adequate. The 600 kHz frequency gives good resolution and accuracy in the measurement of the water current in relatively shallower waters.

For the deeper waters, including those over 70 meters up to about 110 meters, a 300 kHz ADCP will suffice. The lower frequency of 300 kHz can travel deeper through the water while still measuring the water current reliably.

A few of the well-known brands in the market include 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, offering both durability and reliability. With its incredible cost - performance ratio, it provides a great alternative for measuring the water current of the Guaviare 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.