How to measure water current of Iriri River?

1. Where is Iriri River?

The Iriri River is an extraordinary river in a very interesting area. The river crosses the middle of the Amazon rainforest in Brazil, passing serenely across a landscape that is considered one of the wonders of the world.

This river is surrounded by lush, green forests that house a remarkable variety of flora and fauna. Towering trees with entwined branches form thick canopies, in whose shadows countless species live and survive. From elusive jaguars that prowl the forest floor to colorful macaws that soar through the air above the river, the Iriri River is an integral component of this vibrant ecosystem. Along its banks, one can find small indigenous groups deeply connected with the river. These communities rely on it for daily sustenance through its waters, where different types of fish species form the most important constituent part of their diet. Transportation-the river is also a means of movement within and outside of these settlements in the form of canoes that reach scattered areas for hunting and collecting wood.

The Iriri River has a lot of cultural importance as well. The local people have passed down stories and traditions related to the river through generations, tales that speak of its power, its role in creation myths, and its importance in maintaining the balance of life in their world. It is a river that not only shapes the physical landscape but also enriches the cultural tapestry of the region.

2. What is the flow rate of the Iriri river?

The Iriri River is a very important part of the Amazonian ecosystem and for the local communities. It is crucial for the health and biodiversity of the surrounding rainforest.

In terms of its flow characteristics, the flow rate of the Iriri River varies throughout the year. During the rainy season, heavy rains soak the vast Amazon basin, and it swells greatly. Because of the increased volume of water, the flow velocity is higher, and the current is quite powerful; large amounts of sediment and nutrients are moved along and distributed across the floodplains, enriching the soil and allowing a great variety of plant species to grow. During the dry season, the flow rate slows down, with the river being much calmer in many areas. However, it still continues to provide a stable source of water for the wildlife and the local communities.

A very rough approximation of the average flow rate is given by the size of its drainage area, the topography of the area it passes through, and the number and size of its tributaries. All in all, it is a dynamic river whose flow varies with the seasons of the Amazon climate and is integral to the ecological and human aspects of the area.

3. How to measure water current of Iriri River?

There are several common methods to measure the water current of the Iriri River.

Current meter method: This includes mechanical and electronic current meters. These instruments are placed at discrete locations in the river and provide information about the water flow rate past that point. This is not without its own pitfalls, it requires careful positioning at multiple points to get an overall picture of the overall current, and it can often not provide a continuous profile of the current throughout the depth of the water column.

ADCP method: Much more advanced and handy is the ADCP current meter method. This method uses sound waves for measuring the velocity of water at multiple depths all at once. It transmits acoustic signals and analyzes the reflected signals for the Doppler shift to develop a current profile from the water surface down to the bed. This will, therefore, enable the measuring of the water current across sections of the river with much more detail and efficiency.

The buoy method consists of dropping buoys into the river and observing their movement over a period of time. The buoys' travel in a given time will indicate the velocity and direction of flow because of the action of the water current. This method, however, cannot give a good estimate of the detailed velocity variations at different depths. Moreover, there are many other external factors that may affect the buoy's movement, such as wind.

Among these, ADCP current profiler is more sophisticated and handy in measuring the water current of the Iriri River.

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

The principle behind ADCPs is the Doppler principle. When an acoustic signal is sent out from the ADCP profiler transducer into the water, the sound waves elastically scatter off the moving water particles. Since the water is flowing, the frequency of the reflected sound waves that return to the transducer undergoes a change in what is known as the Doppler shift.

If the water is moving towards the transducer, then the frequency of the reflected waves would be higher than the emitted original frequency. On the other hand, in case the water is moving away from the transducer, this frequency will be lower. Precise measurement of this very frequency shift at multiple angles and depths allows the ADCP meter to calculate the velocity in various directions and at different levels of the water column. That provides an advanced profile of the current and gives a picture of how the water moves both on the surface and from there to the bed of the river.

5. What does the measuring device require for high-quality measurement of Iriri river currents?

For high-quality measurements in the Iriri River currents, some of the measuring equipment requirements would include. The materials to be used on the equipment must be highly reliable, since the precision of measurements, which may well be real-time, must remain accurate over time. The device size has to be sufficiently small to assist in the deployment and retrieval of devices within the river, mostly due to areas that can be quite inaccessible within the Amazon rainforest where this Iriri River is flowing. A lightweight design is also of great importance since it greatly simplifies the handling and installation process and makes the process less cumbersome.

Low power consumption is crucial in allowing the equipment to run for long hours without necessarily having to change batteries or implement a complicated power supply infrastructure across isolated areas of the river. The cost, too, is an essential consideration because it will help in the broader application of the technology on a more significant number of measurement campaigns.

For housing the ADCP flow meter, titanium alloy is one of the best options. Some of the key benefits of titanium alloy are. Excellent resistance to corrosion, which is crucial, as the equipment is to be constantly exposed to the river water that may contain minerals, organic substance, and other elements in any number that could potentially damage or degrade the casing. A good strength-to-weight ratio insures that it can stand sufficient durability while keeping the overall weight of the equipment low. Besides, it is resistant to the mechanical stresses during its deployment and operation in the flowing water of the Iriri River.

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

The choice of appropriate equipment for measuring the current of the Iriri River will be based on two major aspects, namely.

First, based on the purpose of use, the Horizontal ADCP-HADCP is recommended for measurement in a horizontal cross-section. It is designed for accurate measurement of flow velocities along a horizontal plane in the river, which gives one insight into the lateral distribution of the current. On the other hand, vertical cross-section measurement would more likely require the Vertical ADCP current profiler since it focuses on profiling from surface to bottom the currents along a vertical line within the water column.

Different frequencies of ADCPs are suited for different water depths. For instance, an ADCP current meter with a frequency of 600 kHz would be ideal in water with depths within 70 meters. This could provide fairly accurate current measurements over relatively shallow sections of the Iriri River. An ADCP at 300 kHz frequency may be more suitable for depths up to 110 meters, useful in sections where the river might be deeper.

There are some popular brands of ADCPs in the market, such as Teledyne RDI, Nortek, and Sontek. However, for those seeking a cost-effective option with excellent quality, the China Sonar PandaADCP is highly recommended. It is crafted with all-titanium alloy material, which not only guarantees durability but also presents an incredible price-performance ratio. You can find out more about it on its official website: https://china-sonar.com/.

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