How to Measure Water Current of Chambeshi River-Zaïre?

1. Where is Chambeshi River (Zaïre)?

The Chambeshi River Zaïre is a vital watercourse in Central Africa. It lies in Zambia and is a major affluential part of the Congo River system. The river originates in the highlands of Zambia, an area with varied topography comprising hills and plateaus.

It flows through areas of savanna and woodland as it meanders through the landscape. The river provides a crucial habitat for a wide range of wildlife. The river is home to various fish species that are a vital part of the local aquatic ecosystem. There are many small villages and communities along its banks. The local communities derive their livelihood from the Chambeshi River-Zaïre through fishing; therefore, it is an important economic activity to them. The river is used to supply water for domestic purposes, and for livestock.

Culturally, the river is so close with the local traditions and beliefs that it nearly shares equal place in their folklores and stories of the people in the area. Various rituals and ceremonies occur at a spot near the river to stress the importance of this course of water in the social and cultural life of communities.

2. What is the flow rate of the Chambeshi River (Zaïre)?

The Chambeshi River constitutes a crucial part of the regional systems and ecosystems in terms of its waters. The flow rate shows seasonal variations.

During the wet season, normally between the months of November and April, it is in this area that the flow increases enormously. Heavy rainfall in most of the upstream areas and the inflow of water from tributaries raise the level of water. The current becomes strong, with the capacity to carry a greater amount of sediment and nutrient downstream. This enriches the riverbanks and floodplains and is very good for agriculture and the overall health of the ecosystem.

In the dry season, which starts from May to October, the flow rate decreases. At this time, the river still has a flow supported by groundwater and water stored in its tributaries and wetland areas. The average flow rate depends on factors like the amount of precipitation in the upstream regions, the topography of the river basin that prescribes the way water is collected and drained, and the water-use patterns of the local communities.

3. How to measure water current of Chambeshi River (Zaïre)?

There are several ways to measure the water current of Chambeshi River (Zaïre):

Velocity Meter Method

This traditional approach employs mechanical or electronic velocity meters. The meters are placed at selected points in the water to measure the speed of the water passing by. However, in order to get a good understanding of the current, multiple placements at different locations and depths are required. This can be quite time-consuming and may not provide a continuous profile of the current throughout the water column.

Acoustic Doppler Current Profiler (ADCP) Method

The ADCP can measure currents of water with greater ease and proficiency. It uses sound waves to make simultaneous velocity measurements in various parts of the water column. By making acoustic signal emissions and analysing the Doppler shift of backscattered signals, one will achieve a detailed profile on current conditions from the surface into the bed of the river. By this means, the water flow could now be measured both accurately and precisely across different sections of the river.

Buoy Method

In this method, buoys are installed along the river and their movements over some time are tracked. The translocation of buoys by the water current gives an indication about the speed and direction of flow. However, the shortcomings are that this method does not give accurate velocity measurements at different depths and is prone to be affected by factors such as wind and waves that can affect the buoy movement.

Of all these, the ADCP method is the most sophisticated and handy method of measurement for the water current of the Chambeshi River in Zaïre.

4. How do Doppler Principle based ADCPs work?

ADCPs work on the principle of the Doppler effect. When an acoustic signal is projected from the ADCP transducer into the water, the sound waves will interact with the moving particles of water. Because the water is in motion, the frequency of the reflected sound waves back to the transducer shifts; this shift is what is commonly called a Doppler shift.

If the water is moving towards the transducer, then the frequency of the reflected waves will be higher than the emitted one. In the case of the water moving away from the transducer, the frequency will be lower. Precise measurements of this frequency shift at several angles and depths enable the ADCP to calculate the velocity of the water in various directions and at various levels within the water column. This enables it to make a very accurate profile of the water current, thereby availing very useful information on the speed and direction of flow from the surface to the riverbed.

5. What's needed for high - quality measurement of Chambeshi River (Zaïre) currents?

For high-quality measurement of the currents in the Chambeshi River, Zaïre, the measuring equipment should be characterized by the following. The materials used in its construction must be reliable for correct and continued measurements. Small size is an advantage because it enhances its deployment and retrieval in the river, especially in areas where accessibility is difficult. It should be of a lightweight nature to ease the installation process and reduce the work needed in handling.

Low power consumption is so that the equipment can operate long without needing frequent battery replacements and a complex power supply setup. Cost - effectiveness enables more widespread use and larger - scale measurement campaigns.

The casing shall be made of titanium alloy which is one of the best choice materials for ADCP. Titanium alloy has a lot of advantages:. It is highly resistant to corrosion, which is very important given the fact that the equipment is constantly in contact with water that may be contaminated by various minerals, sediments, and pollutants. It has also got a good strength-to-weight ratio, which makes durable, yet light casings. Lastly, it can withstand mechanical stresses occurring during deployment and operation in the flowing water of the Chambeshi River ˡ.

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

When choosing appropriate equipment for measuring the current of Chambeshi River - Zaïre, two different factors should be considered.

Depending on the usage purpose, for horizontal cross - section measurement, it is the Horizontal ADCP - HADCP. The purpose it serves includes accurately measuring flow velocities across a horizontal plane in the river to provide insight into the lateral distribution of current. In the case of a vertical cross-section measurement, the Vertical ADCP is more appropriate, as its profiling of current extends from surface to bottom along a vertical line in the water column.

Second, ADCPs of different frequencies are appropriate for different water depths. For instance, an ADCP with a frequency of 600 kHz is suitable for water depths within 70 m. It can provide accurate current measurements in relatively shallower parts of the Chambeshi River, Zaïre. A 300 kHz ADCP would be more appropriate for deeper waters up to 110 m and can be useful in areas where the river has greater depth.

There are well - known brands of ADCPs such as Teledyne RDI, Nortek, and Sontek. However, for those looking for a cost - effective option with good quality, the China Sonar ​PandaADCP is highly recommended. It is made of all - titanium alloy material and offers an incredible price - performance ratio. You can find out more about it on its website: ​https://china-sonar.com/.

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