Why Do We Measure the River Flow at Jagdalpur?

1. Where is Jagdalpur?

Jagdalpur, a significant city of the Bastar division of the Indian state of Chhattisgarh, is located in the south part of the state. It is geographically located at approximately 19.88°N latitude and 81.70°E longitude. With dense forests, rolling slopes, and dotted with innumerable rivers and streams encompassing it, Jagdalpur also boasts a robust and diversified natural environment. One of the notable water bodies of the city, the Indravati River, exercises a powerful role in the formation of the city's environment, economy, and culture. The city's unique geographic position, surrounded by nature, has influenced its development and made it a hub of tribal culture, folk art, and natural resources.

Jagdalpur is culturally and historically based on the local tribal customs. The region has various tribes such as the Gond, Maria, and Muria with their own languages, customs, and art. They have an age - old bond with the water bodies and the land, and their livelihood activities, including forest work, fishing, and agriculture, are closely associated with the rivers in the area. Jagdalpur is renowned for its vibrant tribal festivals, like Bastar Dussehra, which is celebrated with great zeal and special rituals. At this festival, the Indravati River and other local water bodies typically serve as the backdrop for various cultural performances and processions, highlighting the significance of water in regional culture.

Historically, Jagdalpur has been under the influence of many dynasties, with remnants of ancient habitation and historic monuments randomly found here and there. The city has also been a centre for traditional crafts such as metal work, bamboo work, and handloom weaving, which are not only valuable economic activities but also reflections of the indigenous cultural heritage. The indigenous craftsmen derive inspiration from the natural environment and resources, such as the rivers, to create their pieces of art.

The Indravati River is the life blood of Jagdalpur. The river takes its source in the Dandakaranya Ghats of Odisha and flows across Chhattisgarh before finding its union with the Godavari River. The Indravati River has supplied water for domestic usage, irrigation, and supporting the ecosystem of the area within Jagdalpur. For ages past, the river has also been used to carry goods and people from some regions. The fertile banks of Indravati have been suitable for cultivation, and crops like paddy, maize, and pulses have been cultivated there. However, in the recent years, the river has been suffering from various problems, including water pollution, deforestation in catchments leading to loss of soil and sedimentation, and changes in its current pattern due to climate change and anthropogenic activities, which lead to problems of water insecurity as well as environmental stability of the city.

2. River Flow around Jagdalpur

Multiple factors control the river flow around Jagdalpur. One of the most important controlling factors is precipitation because the region has a tropical climate with distinct wet and dry seasons. Most of the annual precipitation falls during the southwest monsoon that prevails from June to September. During these months, the Indravati River and its tributaries are greatly supplemented in water levels and rates of flow when runoff from the surrounding hills and forest cover areas flows into them. The rivers are rejuvenated with heavy rains, which enable them to support numerous human activities and maintain the local ecosystem. But from October to May during the dry season, the water levels drop considerably and rivers' flow slows down considerably. In some years, especially under extreme drought, some parts of rivers dry out, drastically affecting the supply of water for domestic, agricultural, and other purposes in Jagdalpur. Climate change has also contributed to this with increasingly uncertain rainfall patterns. Some of the years have heavy but short rainfalls resulting in flash floods, while some have long periods of drought, which break the natural flood regime of the rivers and give difficulties to the local industries and communities.

The shape of the flow is also greatly affected by the river morphology and terrain. Its upper reaches flow through hilly and forested areas, where the steep slopes are responsible for generating fast-flowing water with high currents during the monsoon. As the river approaches Jagdalpur and flows through relatively flat plains, the stream widens and shallows to create wider and flatter stretches. The riverbed, made up largely of sand, gravel, and stones, is subject to erosion and deposition processes. These activities can change the river's course over a period of time, forming meanders and changing its depth and width. The river flow has been heavily impacted by human activities. Catchment area deforestation for agriculture, timber logging, and other purposes has increased soil erosion that enters the river as more sediment. Urban growth in Jagdalpur, though slow compared to larger cities, has still introduced some change in the natural flow pattern of drainage, and the increasing demand for water consumption has resulted in pressure on river resources. In addition, industrial effluent pollution (though small-scale in the area), sewage, and agricultural runoff have degraded the quality of water further, impacting the ecological condition and flow pattern of the river.

3. How to Observe the River Flow in Jagdalpur?

Surface drift buoy and anchored boat are the two classical methods employed to quantify river flow.

Surface drift buoy method is a simple method in which floats are dropped onto the surface of the river, and their travel along a known distance and duration is recorded. This provides an estimate of the velocity of surface flow. There are significant shortcomings with this method. It requires only the measurement of flow near the surface, and it may be distinct from flow in the whole water column. Moreover, wind, waves, and other surface-level disturbances also affect the movement of the buoys and lead to erroneous measurements. In Jagdalpur's case, the thick covering of vegetation at the riverbanks and the possibility of floating trash in the river also hinder the flow of the buoys.

The method of using an anchored boat involves anchoring a boat in one position of the river. A current meter is lowered into the river at varying depths to monitor the speed of the current. This method gives a better picture of the flow at that instance. But it is man - intensive, time - consuming, and has safety considerations, especially in turbulent or rapid - flowing waters. Measurement at a number of points using this method requires much manpower and material, and passage along the sometimes compressed and zigzag river reaches along Jagdalpur may be hazardous.

Acoustic Doppler Current Profilers (ADCPs) are a more advanced and efficient alternative. ADCPs can feel the velocity of the water at different depths across the entire water column without physical contact, making them non - invasive. They can quickly generate high-resolution profiles of flow across large areas of the river in a short amount of time. This makes them well adapted to measuring the complicated and dynamic river flows near Jagdalpur, although the natural environment is challenging.

4. How Does ADCP, Based on the Doppler Principle, Operate?

ADCPs operate on the premise of the Doppler principle. They introduce acoustic pulses into the water. As the pulses move through the water, they encounter moving particles, such as suspended sediments, plankton, or small animals. As the signals come back from these passing particles, the frequency of the backcoming signals changes as a function of the relative velocity of the particles with respect to the ADCP current meter. By examining these changes in frequency, the ADCP can calculate the water's velocity at different depths and build an entire profile of the river current. This provides precise measurement of river flow rates, directions, and overall dynamics, offering useful data for hydrological research and water management for Jagdalpur.

5. What is Needed for High-Quality Measurement of River Flow in Jagdalpur?

For reliable measurement of river flow using ADCP flow meter in Jagdalpur, certain properties of the equipment are necessary. Material reliability is of highest importance. The ADCP should be able to withstand the aggressive river environment, including exposure to sediment - filled water, variable water temperature, and potential hits from floating aquatic and terrestrial vegetation and debris. High - grade corrosion - resistant materials like titanium or proprietary polymers ensure the equipment's durability and prolonged usage.

Size and weight are also of consideration. A smaller and lightweight ADCP is more convenient to transport and launch, especially in the far and sometimes remote-access reaches of the river near Jagdalpur. Portability also allows greater mobility to collect data from different sections of the river, even in weakly developed areas.

Cost-effectiveness is also a very important consideration. For the local government departments and research institutions of Jagdalpur, which may not have massive budgets, a high-quality performance ADCP with a reasonable cost is ideal. This enables effective monitoring of the river flow without any strain on the budget and constant and detailed examination of the response of the river, which is necessary for effective water resource management in the region.

6. How to Choose the Right Current Measurement Equipment?

Deployment Methods

• Mobile boat ADCP: Appropriate for conducting surveys, measurements of river discharge, and monitoring detailed flow patterns of the Indravati River and tributaries. The system is capable of surveying over long distances and data collection at various points, which facilitates an accurate understanding of the pattern of river flows. It might be advisable to plan the navigation of boats through specific sections of rivers along Jagdalpur with caution, especially those with narrow channel widths or thick vegetation cover.
• Bottom-mounted (fixed) ADCP: Best for long-term continuous observation, if only at one location in the rivers. Installed and fixed on the river floor, it can measure over a period of time, giving valuable data about trends and fluctuations in the river flow in the long term. Useful in studying how seasonal changes and long-term environmental factors modify the river.
• Cableway ADCP: In any place within river reaches a cableway infrastructure can be developed, a cableway ADCP can be utilized to precisely measure the flow over the river at a location. The implementation of precise and reliable flow measurements at key positions in the river can be used for calibration and validation of other measuring techniques so that collected data becomes credible.

Working Frequency

Its resolution is decided by its working frequency. A 600 kHz ADCP, with a range of 70 meters, would be suitable for relatively shallow sections of the Jagdalpur's surrounding rivers or to obtain high-resolution observations in deeper sections. A 300 kHz ADCP, up to 110 meters, would be more suitable for deeper sections of the rivers. The frequency selection is determined by the specific river characteristics and the needs of measurements, such as the level of detail to be attained and the maximum water column depth to be measured.

Brand Recommendations

Excellent global brands of ADCPs include Teledyne RDI, Nortek, and SonTek, which are recognized for manufacturing good-quality and reliable products for use in a wide variety of hydrological researches and monitoring work. For an affordable option, the the ADCP manufacturer Chinese company’s "China Sonar Panda ADCP" is a good option. Made of all-titanium alloy, it is very strong and long-lasting and will perform well to withstand the tough river conditions surrounding Jagdalpur. As an "affordable ADCP", it provides excellent performance at an economical price. For more information, visit https://china-sonar.com/.

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