ADCP in Flood Prevention Management of the Bermejo River

Its applications in flood prevention (velocity and flow measurement, sediment transport research), data utilization for flood warning and risk management.

I. Where is the Bermejo River?

Natural and Geographic Features 

The Bermejo River is situated in South America. It originates in the Andes Mountains of Bolivia, marking part of that country's border with Argentina, before finally discharging into the Paraguay River. Very long and winding, its course crosses various kinds of terrain, ranging from high altitudes to arid plains and wetlands. In most of its flow, the channel is pretty wide, with important water volume showing strong variability in its volume according to the rainfalls.

Cities and Settlements Along the River 

There are several towns and villages along the course of the Bermejo River. These communities depend upon the river for water supply, fishing, and limited agricultural activities. In some places, the river offers a route of transportation to small boats.

Rainfall Situation 

The climate of the Bermejo River basin varies between more humid in the upper reaches, due to Andean influence, to semi-arid in the middle and lower parts. In the upper regions, rains are highly concentrated during the summer period, while at the lower regions the rainfall is highly erratic. During springtime, snowmelt of the Andean peaks adds to the water in this river.

II.What are the causes of flooding in the Bermejo River?

​Causes of Floods

  1. Heavy Rainfall: Heavy rainfall in the wetter months, especially in the upper reaches of the basin, was one of the major causes of flooding. The huge quantum of water entering the river brings about a sudden rise in the level of the water. Most of the excess water runs off into the river as the soil in the area may become saturated, hence over-flooding.
  2. Snowmelt: Since there are Andean peaks in the higher catchment areas, the snow melting during spring could lead to an instantaneous inflow of water. This, when occurring along with heavy rainfall or an especially fast melting of snow due to a sudden rise in temperature, results in the swelling of the river and flooding.
  3. Tributary Overflow: There are several tributaries into the Bermejo that collect water from various sub-basins. Where these have higher volumes of water from either local heavy rainfall or snow melt, they feed into the main river and increase the total volume of water on the move, thereby increasing the risk of flooding.
  4. Geographic Features: The river meanders very badly, and flat plains or wetlands coming in its way are liable to be flooded. In the case of high-water events, natural levees along the river may be breached, allowing water to spill onto surrounding areas.

Frequency and Scale of Floods 

The Bermejo River exhibits seasonal flooding, especially in the months of spring and summer. At times, there is only a minor flood, where it affects only the riverbanks and low areas of them, while other times heavy ones may inundate vast plains area and affect the way of life and livelihood of the people along its course. 

Effects of Floods

  1. Infrastructure Damage: Floods can affect bridges, roads, and water-supply infrastructure. This may lead to the isolation of communities with reduction in access to basic services, especially in rural settings.
  2. Agriculture and Livelihood Impacts: Most of the farmland in the path of the Bermejo are prone to flooding. Crops may get destroyed, while good soil gets washed away. Fishing is also hampered; therefore, livelihoods within these communities are affected.
  3. Displacement of People: In extreme cases of flooding, there is the need to move people from low-lying areas. In such instances, temporary displacement may result with the consequence of needing emergency shelter and relief supplies.

The ADCP current meter will give a more technologically enhanced and smoother way to measure and understand the flow of the Bermejo River for flood prevention and control.

III. How do ADCPs using the Doppler principle work?

Acoustic Doppler Current Profiler(ADCP) operate under the Doppler principle. They transmit acoustic pulses, or simply sound waves, into the water. These acoustic pulses are reflected back to the ADCP after interacting with the moving water particles. Due to the Doppler effect, the frequency of the reflected sound waves is changed. Such a change in frequency is linearly proportional to the velocity of the water particles.

In the case of the Bermejo River, the ADCP current profiler can be mounted on boats, floating platforms, or fixed stations installed near the riverbanks. The instrument emits a sequence of sound pulses at a predetermined frequency. The received and reflected signals internally analyze it in the ADCP. By calculating the frequency shift of the reflected signals from different depths, the velocity of the water column for different depths can be determined. The information is then processed and presented with real-time information on the water flow in the Bermejo River.

IV. What are the applications of ADCP in floods of the Bermejo River?

Velocity Measurement 

The ADCP doppler is one of the essential tools used in river flow velocity measurement. By properly gauging the exact velocity at every depth and location along the river, it delivers relevant information on flow dynamics. This information becomes critical in predicting downstream movements of floodwaters and the erosive power of the water. For instance, during a flood, high-velocity water may cause much heavier erosion of riverbanks and areas of floodplains.

 Application of Flow Measurement 

The measurement of the flow rate in the Bermejo River by ADCP flow meter is vital in flood control. By accurately determining the amount of water actually passing through a given cross-section of the river, the flood management authorities can go on to estimate the quantity of water that could cause flooding. This is used in operating any flood-control structure such as weirs or small dams and managing the water level. 

Application to Sediment Transport Research 

Bermejo River carries a considerable amount of sediment during flood events. This technique can be useful in measuring the concentration of sediments and the sediment transport rate by means of ADCP meter. The movement of sediments needs to be understood as part of an essential element of maintaining the health of the river and its ecosystems. In this respect, all the data received may allow forecasts regarding where sediment depositions will appear; it is crucial for land-building processes and the long-term development of the river and its flanking areas accordingly.

V. How can the data measured by ADCP be utilized in order to contribute to the flood warning and risk management of the Bermejo River?

Flood Warning

Velocity and Flow Data Monitoring The ADCP profiler will continuously monitor the velocity and flow rate of the Bermejo River. This can be done by setting up threshold values for such parameters so an alarm can be raised regarding abnormal rise in water flow. For example, in case the velocity or flow rate of water crosses a value threshold, this may imply that a flood is imminent. The early warning system thus enables timely evacuations of people residing in flood-prone areas, besides activating flood-protection measures. 

Water Level Prediction and Warning Data integration from ADCP with hydrological data, such as rainfall measurement, estimation of snow melt for better water level prediction; comparison of predicted water levels against known historic flood levels allows the warning of communities in good time well in advance. 

Risk Management

Water Conservancy Project Scheduling Decision Support  The ADCP data provides useful information in the operation and scheduling of water conservancy projects along the Bermejo River. As an example, the flow rate and the velocity data can be used to determine how much water should optimally be released from any structure for flood control, yet satisfying the water supply needs below the dam. It also allows for the design and maintenance of flood-protection infrastructures like levees and flood-walls.

Flood Disaster Assessment and Emergency Response  Once a flood has taken place, ADCP data can be directed to assess the extent of the disaster. With the analysis of post-flood patterns of velocity and water depth, the area that has been most affected is well understood in an emergency response. This shall help in planning the rescue operations, distributing relief supplies, and the long-term recovery and reconstruction efforts. 

VI. What does it take to make a quality measurement of the Bermejo River currents?

Reliability of Equipment Materials

The equipment to be used in the measurement of Bermejo River currents should be quality and reliable. For instance, the casing of ADCP is preferably made of titanium alloy. Titanium alloy has excellent strength in withstanding the pressure and physical forces within Bermejo River. The metal is also greatly resistant to corrosion by water and sediment, hence guaranteeing long-term durability of the equipment. 

Small Size An edge that the Bermejo River has is that an ADCP of small size has been deployed. It can also easily be installed on different platforms such as small boats, buoys, and riverbank monitoring stations without causing significant obstruction in the flow of the river. Thus, it has given more leeway with respect to its placement position to get comprehensive current measurements. 

Light Weight Light - weight ADCPs are lighter to carry and install, something that is more in the remote areas along the Bermejo River. A field technician can carry them at different locations and mount for measurement with rapidity. This becomes particularly important during an emergency flood-monitoring situation. 

Low Power Consumption

 Long-term monitoring of the Bermejo River will need ADCPs with low power consumption. Since the river is very extensive and continuous data needs to be collected from this river, equipment that could operate for extended periods without frequent battery replacement or without disrupting power supplies is highly desired. 

Low Cost The cost of ADCP equipment should, however, be fairly affordable to accommodate large-scale measurements across the Bermejo River. This way, as many units as possible could be set up at various points across the river, where one can get a better view of current patterns and flood risks within the same area.

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

By Intended Usage

  1. Horizontal Cross-Section Measurement Horizontal ADCP is preferred for horizontal cross-section measurement in the Bermejo River. HADCP can measure the velocity and flow rate across the width of the river, thus giving full information on the flow characteristics of the river at any particular cross-section. This is an important part in understanding how water spreads across the river and for flood-plain management.
  2. Vertical Cross - Section Measurement When it comes to vertical cross-section measurement, a vertical ADCP fits best. This gives the water's velocity and flow rate at different depths and thus helps in carrying out an analysis of the vertical structure of the flow of the river. This is quite indispensable when one needs to understand the stratification of water and the movements of sediment. 

Choose Different Frequencies

This, however, depends on the depth in which Bermejo River has to be selected. Usually, for areas that are 70 meters deep, a frequency of 600 kHz ADCP may work; where the topography is even deeper, such as up to 110 meters, an ADCP of 300 kHz becomes more appropriate.

 Finally, there are several well - known ADCP brands such as Teledyne RDI, Nortek, and Sontek. However, for cost - effective and high - quality ADCPs, the Chinese brand ChinaSonar PandaADCP is highly recommended. It features an all - titanium alloy material construction and offers excellent value for money. You can visit(https://china-sonar.com/) for more information.

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

Brand model
Teledyne RDI Ocean Surveyor ADCP, Pinnacle ADCP, Sentinel V ADCP, Workhorse II Monitor ADCP, Workhorse II Sentinel ADCP, Workhorse II Mariner ADCP, Workhorse Long Ranger ADCP, RiverPro ADCP, RiverRay ADCP, StreamPro ADCP, ChannelMaster ADCP, etc.
NORTEK Eco, Signature VM Ocean, Signature, AWAC, Aquadopp Profiler, etc.
SonTek  SonTek-RS5, SonTek-M9, SonTek-SL, SonTek-IQ, etc.
China Sonar PandaADCP-DR-600K, PandaADCP-SC-300K, PandaADCP-DR-300K,PandaADCP-DR-75K-PHASED, etc.
Jack Law September 22, 2024
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