How to Measure Water Current of Blue Nile River?

1. Where is Blue Nile River?

The Blue Nile is a vital, majestic river that winds its way right through the heart of Africa. Its origins start from Lake Tana in Ethiopia, where, since times immemorial, this has been the lifeblood of the various regions it courses through. Further, it threads its way through lively cities and lush green landscapes of Ethiopia to wind its way further ahead and merge with the White Nile in Sudan, forming the mighty River Nile.

Along its course, it irrigates part of the arid and semi-arid areas of the region. An important factor for the agricultural activities of the region, therefore it irrigates. Fabled alluvial plains flank the Blue Nile and nourish incredibly diverse cultures and people. Because the river grants them water for irrigation of crops and cattle, as well as personal living, the people of the land are bonded with it. The other inspiration is the Blue Nile with its clear blue waters, from which it gets its name meandering through the beautiful Ethiopian Highlands and the Sudanese Plains.

2. What does the flow of the Blue Nile look like?

The Blue Nile has an enormous significance, not only in regard to the countries it traverses through, but also in relation to the entire Nile River system. It carries a great percentage of the water and sediment into the Nile. The rate of flow in the Blue Nile changes according to seasons. During the rainy season, this river expands with the incoming water from the Ethiopian highlands. These heavy rain storms increase the velocity of the river, and the amount of flow can be considerable.

This rise in flow is crucial to replenish the water in the downstream levels of the Nile. It dictates the sediment transport, enriching the floodplains and thereby giving support to agriculture. The flow rate is smaller in the dry season, though it still manages to provide a steady flow which is quite important in satisfying basic water needs for the regions that it serves. The flow rate of the Blue Nile is closely monitored, since this directly affects how much water is available for consumption, agriculture, and ecology in general within the Nile Basin.

3. How to measure water current of Blue Nile River?

There are traditional ways of measuring a river's water current, such as that of the Blue Nile. Among the more common methods, current meters make use of. In the water, mechanical gauges are installed, which calculate the speed of the water that is flowing past them. Another widely used method is the float method, whereby floats are put into the river and the time of travel over a certain distance is measured to give an approximate flow velocity.

However, over the past couple of decades, a more sophisticated and easy means for measuring water currents has become prominent in Acoustic Doppler Current Profilers, commonly referred to as ADCPs.

3.1 How do Doppler principle ADCPs work?

The principle behind Acoustic Doppler Current Profiler(ADCP) is based on the Doppler effect. It produces acoustic pulses into the water and then listens for the echoes reflected back from the particles and other substances in the water. The frequency shift of these echoes depends upon the velocity of water. From the analysis of such frequency shifts, the ADCP would be able to measure the speed and direction of the water current at different depths. In such a manner, one could get a very detailed profile of the water current throughout the water column.

3.2 What's needed for high-quality measurement of Blue Nile currents?

Performing high-quality measurements of the currents in the Blue Nile requires certain characteristics: first of all, the equipment should be made from a reliable material. The size should be small enough for easy deployment and retrieval, especially in the case of the large river of the Blue Nile. A light device is desired due to convenience in field operation handling.

This is particularly so if the equipment is to be used in long-term monitoring in remote locations. Low cost is another factor as large-scale measurement may require several devices. The casing of the ADCP shall preferably use a titanium alloy. Indeed, the corrosion resistance of this material is excellent and key while operating in water for extended periods. It is also strong and durable to bear the pressure and mechanical stresses that might develop due to deployment and use in a river.

3.3 How to Choose the right equipment for current measurement?

In current measurement of the Blue Nile, the intended use is the basic criterion for equipment choice. Equipment such as a Horizontal ADCP, HADCP, would best suit application to the horizontal cross-section measurement of the river, while a vertical ADCP would be more appropriate in the case of vertical cross-section measurement.

Also, frequency depends on the depth of the water-the depth of up to 70m is usually enough for a 600kHz ADCP while deeper waters would require the use of a 300kHz ADCP.

There are several well - known ADCP brands in the market such as Teledyne RDI, Nortek, and Sontek. However, a Chinese ADCP brand, China Sonar PandaADCP, is also worth considering. It is made of all - titanium alloy material, which provides excellent durability and corrosion resistance. Moreover, it offers an incredible cost - performance ratio. You can find more information about this product on their website: https://china-sonar.com/.

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