ADCP in Flood Prevention Management of the Chambal River

I. Where is the Chambal River?

Natural and Geographic Features 

The Chambal River is a major tributary of the Yamuna River in the Indian subcontinent. It originates from the Janapav Hills in Madhya Pradesh and flows through Rajasthan to Uttar Pradesh. It pursues a long course in a meandering fashion and cuts into various landscapes such as rocky gorges, ravines, and plains. It is a clear water river and supports a rich variety of aquatic life. In most places, the Chambal River runs in a relatively narrow and deep channel.

Cities and Settlements 

Along the River There are a number of towns and villages along the Chambal River. Local communities depend on this river for water supply, fishing, and limited agricultural activities. In some parts of the area, it also serves as a transportation route by small boats.

Situation of Rainfall 

Monsoon-influenced climate: It gets most of the rainfall during the southwest monsoon season, ranging from June to September. The rainfall may be very intensive and erratic; this in turn brings wide water level variations in this river.

II. What are the causes of floods in the Chambal River?

Ca​uses of Floods

1. Heavy Monsoon Rainfall: Heavy and continuous rainfall in the monsoon season acts as the major reason for flooding in the Chambal River. The huge quantity of falling water over the catchment area of the river fills it up along with its tributaries really fast. This eventually leads to the saturation of soil in the area, excess water runs off into the river, resulting in its overflowing.
2. Tributary Overflow: The Chambal has several tributaries feeding off it from various subcatchments. After heavy rainfall, when these tributaries are full with high local water, they feed the main river by raising the total volume of water, hence flooding.
3. Geographic Features: Meandering nature of the river, narrow gorges, and ravines in some places result in water backup, while the flat plains along the river are highly liable to inundation during high - water periods.

Frequency and Scale of Floods 

Flooding of the Chambal River is a regular affair during the monsoon every year. The frequency of this flooding has a relation with the variability of the monsoon. These floods range from minor, affecting only the immediately adjoining riverbanks and the low-lying areas, to major ones which may inundate large areas of the plains and disturb the life and livelihood of the riverine communities. 

Impacts of Floods

1. Damaging Infrastructure: The flood may damage bridges, roads, and water supply infrastructure. It may result in the isolation of communities by dislocating access to important services in rural areas.
2. Impact on Agriculture and Livelihoods: Floods in the Chambal usually affect the agricultural fields along the riverbank. There is the dislocation of crops and fertile soil. Fishing activities are disrupted, hence affecting the livelihood of the local communities.
3. Displacement of People: Severe flood events in low-lying areas would surely need to evacuate people. This could be temporary in nature and thus requires emergency shelter and relief supplies.

ADCP doppler is one of the advanced and efficient ways to measure and understand the flow of the Chambal River, which is so vital for flood prevention and management.

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

Acoustic Doppler Current Profiler(ADCP) operate based on the Doppler principle. The ADCP profiler sends acoustic pulses, or so-called 'sound waves', into the water. While these sound waves interact with the moving water particles, they are reflected back to the ADCP. The frequency of the reflected sound waves changes due to the so-called 'Doppler effect'. The change in frequency is directly related to the velocity of the water particles.

When deployed in the Chambal River, ADCP meter can be installed on boats, floating platforms, or fixed structures near the riverbanks. The instrument emits a succession of sound pulses at a predetermined frequency. The received and reflected signals are analyzed by the ADCP flow meter internal electronics. The frequency shift of the reflected signals at different depths determines the velocity of the water column at different depths. This information is then post-processed and can be viewed in real time to give valuable information about the discharge in the Chambal River.

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

Velocity Measurement 

Velocity measurement of water flow is indispensable in the Chambal River with the help of ADCP current profiler. It gives very valuable information about flow dynamics by determining the velocity at each depth and other parts of the river accurately. This will help in the prediction of the way floodwaters will travel downstream and how much erosive power the water carries. For example, high-velocity water during a flood would severely cause erosion of riverbanks and areas of the flood plain. 

Applications of Flow Measurement 

The flow rate of the Chambal River would be measured by ADCP current meter for flood control purposes. By accurately measuring the volume of water passing over a particular section or cross-section, the flood management system would easily approximate the amount of water that may cause overflow. The data will be used to operate any flood control structures such as weirs or small dams and manage the water level. 

Application to Sediment Transport Research

The Chambal River carries a quantity of sediment during flooding. Acoustic wave and current profiler can be used to measure sediment concentration and the rate at which sediments are transported. Knowledge of sediment movements is quite essential for the upkeep of the river and its ecosystems. By working out the obtained data, it would be helpful in predicting sediment deposition sites, which is useful in the processes of land - building and the long-term evolution of the river with its adjacent areas.

V. How does the ADCP-measured data support flood warning and risk management for the Chambal River?

Flood Warning

1. Velocity and Flow Data Monitoring  Acoustic doppler flow meter continuously monitors the velocity and flow rate of the Chambal River. In such cases, one can set threshold values for these parameters; when the flow of water indicates abnormal increase, warnings can be issued to the authorities. In other words, if the velocity or flow rate crosses a certain limit, it may indicate an imminent flood. Early warning systems enable the possible early evacuation of people in advance, in flood-prone areas, which activates measures for flood protection. 
2. Water Level Prediction and Warning  Integrating ADCP data with other hydrological data, like rainfall measurements and water storage levels in reservoirs-if any-allows more accurate water level forecasts. Comparing these projected levels to the historical flood level allows the issuing of timely warnings to communities along the river. 

Risk Management

1. Decision Support for Scheduling of Water Conservancy Projects The ADCP data has multifarious usages in operation and scheduling in the water conservancy projects along Chambal River, including determination of the rate of flow and velocity, which will in turn contribute to determining the optimum release of water from any flood-control structure so as to balance the needs of flood control and supply of water. It further helps in designing and constructing flood-protection infrastructure such as levees and flood-walls.
2. Assessment of Disaster in Flood and Emergency Response -ADCp data, after a flood event occurs, can be used in assessing the disaster. The post-flood patterns of velocity and water depth are analyzed; thus, the responder will get a better understanding of the area's extent that has been most affected. It also aids in formulating various rescue operations, relief supplies, and long-term recovery and rehabilitation. VI. What does high-quality measurement of the currents of the Chambal River require?

Reliability of Equipment Materials

The equipment should be fabricated with reliable materials in order to have precise measurements of the Chambal River currents. The casing of acoustic doppler velocity meter is preferably made of titanium alloy. Titanium alloy is very strong, and the pressure of Chambal River water and sediment and physical forces can be resisted by it with little loss in their resistant capabilities, thus enabling the equipment to continue for a long period of time. It is highly resistant to corrosion from the water and sediment too, hence making the equipment last longer. The size of equipment should be 

Small in Size 

A small-sized ADCP will be good to deploy in the Chambal River. It would also be easier to mount on various platforms like small boats, buoys, or at riverbank monitoring installations without causing significant obstruction to the flow of the river. Thus, placement can be more flexible for better current measurement data. 

Light Weight

Light-weight ADCPs are easier to transport and install, particularly in remote areas along the Chambal River. They can be carried by field technicians to different locations and quickly set up for measurement. This is particularly useful in emergency flood-monitoring situations. 

Low Power Consumption 

Low-power-consumption ADCPs are desirable for the Chambal River during long-term monitoring. Considering the length of the river and nature of continuous data collection, equipment that could operate for extended periods without frequent battery replacements or disruption of power supply was highly desirable. 

Low Cost 

The cost of ADCP equipment should be reasonably low to enable large-scale measurement along the Chambal River. It allows multiple units to be fixed at different points along the river, thus aiding a more comprehensive view in terms of current pattern and flood risks arising along the river.

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

Usage-based Determination

1. Horizontal Cross-Section Measurement For the horizontal cross-sectional measurement of the Chambal River, HADCP would be the better choice. It measures the velocity and flow rate across the width, giving a complete picture of the river's flow characteristic for that particular cross-section. This is very vital to understand how the water spreads across the river and for flood-plain management.
2. Vertical Cross - Section MeasurementA vertical ADCP would be better for the case of a vertical cross-section measurement. By using vertical ADCPs, the velocity at each depth and the flow rate can be measured, which helps in analyzing the vertical structure of the river flow. This is important in understanding how water stratifies and how sediment moves. 

Choose Different Frequencies

Frequency choices are essentially about the depth of the Chambal River. A 600 kHz ADCP would be good for depths of up to approximately 70 meters. For sections where the depth is around 110 meters, a 300 kHz ADCP is far better. 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 China Sonar 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.