Why Do We Measure the River Flow in Mathura?

1. Where is Mathura?

Mathura, located in the northern Indian state of Uttar Pradesh, holds a significant position on the Indian map. Located at around 27.44°N latitude and 77.70°E longitude, Mathura lies on the Yamuna River. The city is situated nestled in the fertile Indo-Gangetic Plain, characterized by its flat topography that has enabled agriculture to flourish and urbanization to thrive over centuries. The flat plain not only permits large-scale farming but also enables a best situation for infrastructure and human settlements to be developed.

Mathura is one of India's most significant cities culturally and historically. It is said to be the birthplace of Lord Krishna, a sacred god in Hindu mythology, and has therefore been a center of cultural and religious activity for two millennia. The city is dotted with a number of ancient temples, such as the Krishna Janmabhoomi Temple, which attracts millions of pilgrims every year. These temples are not only pilgrimage centers but also stores-house of India's architectural wealth, with intricate carvings and characteristic designs. Mathura's cultural significance is not just limited to religion; its festival celebrations, folk songs, dances, and indigenous handicrafts make it unique.

The Yamuna River forms the backbone of Mathura. Rising from Yamunotri Glacier in the Garhwal Himalayas, it flows for about 1,370 kilometers until it merges with the Ganges River at Allahabad. In Mathura, the Yamuna has been a central theme of various aspects of life. Historically, the Yamuna was a significant trade route, facilitating smooth movement of commodities and fueling economic growth. Currently, it also provides water for domestic use, agriculture, and some industrial operations. But the river also suffers from critical hazards due to industrial waste, sewage discharges, and agricultural run-off that have direct impacts on the water supply of the city and the health of its ecosystem.

2. What is the River Flow near Mathura?

There are several factors influencing the river flow near Mathura. Rainfall and run-off are causative factors. The region experiences a monsoon season between June and September, with heavy and often spasmodic rainfall. During this period, the Yamuna River experiences an increase in water level and discharge rates as runoff from the surrounding landscape, including the hilly regions in the north, enters the river. On the contrary, the dry season between the months of October to May suffers from an astonishing reduction in water levels, with the flow greatly diminished. Climate change has also exacerbated the situation, with increasingly erratic precipitation patterns and potentially increased severity of flood and drought events.

The river and terrain morphology also influence the flow. The low-lying plains enable the river to meander, producing wide, shallow reaches and narrower, deeper channels. The riverbed, which is predominantly sediment, is subject to ongoing processes of erosion and deposition, in turn altering the river's form and depth and, hence, local patterns of flow. Morphological adjustments can affect the transport of water and sediment and, in turn, influence aquatic environments and flood-prone regions.

There are also barrages, dams, and reservoirs in the upstream that control the release of water. For example, the Hathnikund Barrage regulates the flow of water of the Yamuna by collecting it during the monsoon and releasing it slowly during the dry season to meet the water requirements of the downstream area, which is composed of Mathura. But indiscriminate management of release of water or unforeseen circumstances such as heavy rainfall upstream can lead to sudden rises in water levels and cause Mathura floods. On the other hand, a lack of release of water during drought can exacerbate the urban water shortages in the city.

Historically, Mathura has had a few significant hydrologic events. Excessive monsoon rains in 2016 caused a serious Yamuna flood. According to reports from the local disaster management agencies, the flood inundated large parts of the city, damaged infrastructure, and impacted thousands of individuals (Source: Local Disaster Management Reports, Mathura, 2016). Tracking these events is required to develop flood control measures effectively, safeguard the lives and properties of the citizens, and ensure sustainable management of the water resources under changed environmental conditions.

3. Observe River Flow in Mathura How?

Surface drift buoy method and anchored boat method are the conventional methods for measuring river flow.

Surface drift buoy method is a quite simple method. Surface floats are released on the river, and the floats' displacement in a known distance and time is measured. This provides a rough estimate of the surface velocity of flow. This method, however, has a number of constraints. It can estimate only at the surface, which might not be representative of the whole water column flow. Wind also has an overwhelming effect on the buoys' movement and causes erroneous readings.

The anchored boat technique involves the anchoring of a boat in a selected point in the river. A current meter is then released into the water at various depths to measure the velocity of flow. This method gives a more complete picture of the flow at that particular point. Although, it is time - consuming, labor - intensive, and dangerous as far as safety is concerned, especially in turbulent or high - flowing waters. The application of this method to take measurements at various points requires huge manpower and resources.

Acoustic Doppler Current Profilers (ADCPs) offer a superior and more cost-effective option. ADCPs can measure the water velocity at different depths across the whole water column without physical contact, hence not invasive. They can produce high-resolution flow profiles rapidly that cover large sections of the river within a short time frame. They are highly suitable to observe the dynamic and complicated river currents that envelop Mathura.

4. How Does ADCP, Which Operates on the Doppler Principle, Work?

ADCPs operate on the Doppler principle. They emit acoustic pulses into the water. As these pulses travel through the water, they encounter moving particles, such as suspended sediments, plankton, or small life. As the signals bounce off these traveling particles, their frequency changes likewise as per the velocity of the particles relative to the ADCP. Based on these changes in frequency, the ADCP can calculate the velocity of the water at various depths to create a comprehensive profile of the river flow. This allows for accurate measurement of river flow rates, directions, and general dynamics, to support beneficial data for hydrological studies and water resource management.

5. What is Required for High-Quality Measurement of River Flow in Mathura

For high-quality river flow measurement by ADCP in Mathura, there are several equipment requirements. Material reliability is especially of concern. The ADCP should be capable of withstanding the hostile river environment, which includes exposure to water, abrasion by sediments, and varying water temperatures. High-quality, corrosion-resistant materials, such as titanium or special polymers, give the device durability and longer life, allowing it to function effectively for extended periods.

It is also crucial to consider the size and weight. A compact and lightweight ADCP is easier and more convenient to install, especially where the accessibility is limited or the river conditions are poor. It is particularly relevant for conducting surveys of the complex river networks of Mathura, where handiness and maneuverability can go a long way in increasing the efficiency of the data collection process.

Cost-effectiveness is also a top consideration. For long-term or large-scale monitoring programs, a good-quality ADCP at affordable price is the best option. It offers larger coverage and more frequent measurements and enables general river flow monitoring without too great an expense.

6. How to Select the Most Suitable Current Measurement Equipment?

Deployment Methods

• Mobile boat ADCP: Ideally suited for executing surveys, measuring discharge in rivers, and mapping detailed flow conditions. It can easily cover long stretches of the river within a matter of minutes and is therefore ideal for surveying the complete length of the Yamuna along Mathura. It is capable of collecting data at multiple locations, thus providing overall information about flow patterns of the river as well as demarcating areas of concern.
• Fixed bottom (bottom-mounted) ADCP: Best suited for continuous record over long periods. Once installed on the river bed, it can make measurements over extended periods, providing valuable information on long-term trends and fluctuations in the river flow. This is useful in determining the ecological impact of water management practices and predicting likely long-term changes in the river's behavior.
• Cableway ADCP: Where there is access to a cableway in river reaches, a cableway ADCP can be used. It is placed over the river and can measure the flow over the river at one location. The technique is useful for obtaining precise and consistent flow measurements at significant locations in the river, which can be applied for calibration and validation of other measurement techniques.

Working Frequency

The frequency at which an ADCP operates determines its range and resolution. A 600 kHz ADCP may have a maximum range of about 70 meters, which would be appropriate for fairly shallow stretches of the Yamuna or to make high-resolution measurements over deeper stretches. A 300 kHz ADCP would measure up to 110 meters and is thus appropriate for deeper stretches of the river. Higher frequencies can deliver more resolution but with less range, while lower frequencies have a greater range but less resolution. The frequency to be employed will be dependent on the specific features of the river and the measurement needs, such as the detail required and maximum water column depth to measure.

Brand Recommendations

Globally, well-known brands of ADCPs include Teledyne RDI, Nortek, and SonTek. These brands are well-known for their quality products, state-of-the-art technology, and consistent performance. However, if one desires a low - cost option, the ADCP manufacturer Chinese brand "China Sonar Panda ADCP" is an ideal choice. This "economy ADCP" is made of all - titanium alloy material, which is extremely robust and corrosion - proof. It is extremely cost-saving, hence applicable for a wide range of uses, from small-scale research work to neighborhood water management projects. For more information, you can visit their site at https://china-sonar.com/.

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