Why We Measure the Parachinar River Flow？

1. Where is Parachinar?

Parachinar is a significant city in Kurram District of Khyber Pakhtunkhwa province of Pakistan. Geographically, it falls in the north-western part of the country in the arid and mountainous region of the Kurram Valley. The city is surrounded by craggy, rocky mountains, which form a natural boundary and impart its terrain a unique shape. Parachinar is at a height of about 1,600 meters above sea level and enjoys a semi - arid climate. The summer is hot and dry and the winter gets chilly with sporadic snowfall on the higher reaches of the surrounding mountains. The hilly landscape not only influences the local environment but also plays a major role in the hydrology of the region, with implications for water run-off and river flow regimes.

Parachinar is culturally settled predominantly by the Kurram Pashtuns, who share a rich, distinct cultural heritage. The Pashtun tradition forms the bedrock of the local culture since it appears in a host of spheres such as social norms, music, dance, and handicrafts. Pashtun folk music, soulful melodies and rhythmic beats, and folk dances form a significant part of celebrations in the community. Local handicrafts such as hand - carved wooden items and beautifully embroidered fabrics testify to the local skill. The city is also religiously significant with a large number of mosques and shrines, which bespeak the strong Islamic devotion of the people. Parachinar has traditionally been a strategic center on trade routes, enabling the trade of goods and ideas among the different regions, which has added to the cultural enrichment of its diversity.

The Kurram River is Parachinar's main river system. The Kurram River has its source in the Hindu Kush mountain range. It runs along the Kurram Valley, meandering its course through the mountainous terrain and passing right through the city of Parachinar. This river is the lifeline of the region. It gives the primary source of fresh water for consumption, irrigation in farming, and grazing of livestock. In farming, a major economic activity within the region, water from the Kurram River is used in irrigating crops so that wheat, maize, and fruits can be cultivated. The Kurram River also has the capacity to contribute to the regional ecosystem by supporting rich water life and providing habitat to different species of fish, birds, and other creatures. The river also has potential for small-scale hydroelectric power generation, which can assist in fulfilling the energy needs of the region and promote economic growth. Throughout its course along the side of Parachinar, the river has some small tributaries that it receives, adding additional volumes of water and influencing the hydrological processes within the area.

2. What is the River Flow near Parachinar?

Influence Factors

• Precipitation and Runoff: Due to the semi-arid nature of Parachinar, there is hardly any precipitation throughout the year. Rainfall is all concentrated between the monsoon season, typically July and September. But precipitation is relatively low compared to other more moist regions. Snow falls in the higher reaches of the neighboring mountains during winter. Thaw of this snow during spring and early summer contributes significant volumes of water to the Kurram River, increasing its flow. Heavy though infrequent rains during monsoon can cause sudden rises in river levels and flow rates. Apart from these seasons, river low flows dominate, and even parts of the river go dry in some years of drought, especially towards the upper reaches. River runoff depends on the intensity and duration of rainfall, rate of melting of snow, and the ability of the soils to retain and hold water within the mountainous catchment basins.
• Topography and Morphology of Rivers: The hilly terrain of the Kurram Valley greatly controls the course of the Kurram River. Through the hilly areas in the upstream, the river flows through narrow gorges and steep-sided valleys, where the slope is steep, generating rapid, turbulent flows with extensive erosive power. Since it passes near Parachinar and through the relatively wider valley of the city, the slope eases off, and some sections of the river widen. However, the riverbed consists of a mix of rocky, gravelly, and sandy material, which creates resistance to flow and influences the speed and direction of the water. The meandering of the river also forms areas of different flow properties, such as outer bends with faster and inner bends with slower flow. These physical properties of the river not only affect the flow patterns but also affect the transport and deposition of sediment, continuously changing the channel of the river with time.
• Reservoir Operation: There is no single large-scale reservoir directly influencing the stream flow of the Kurram River near Parachinar. However, small-scale water storage structures and irrigation canals are used to manage water for agricultural and domestic purposes. There may be more significant reservoirs constructed in the future to regulate the river flow, store water during high-flow periods, and release it when dry to supply a more stable water resource. Such developments would profoundly change the natural flow regime of the river, levelled-out water supplies around the year.

Historical Hydrological Events

It was challenging to obtain detailed and reliable information on specific historical major flood and drought events in Parachinar due to few historical records within the region. However, given the semi-arid climate and the dependence of the population on the Kurram River, both floods and droughts would have occurred in the past. Floods, although infrequent, can be disastrous when monsoon rains are torrential and the river overflows its banks, razing infrastructure, homes, and crops. Droughts, on the other hand, can lead to severe deficiencies in water, affecting domestic water supply, agricultural output, and the overall economy of the people. River flow observation is important in order to predict and plan for such events, as well as to effectively utilize water resources during normal as well as unfavorable conditions.

3. River Flow Observation in Parachinar

Traditional Methods

• Surface Drift Float Method: Surface drift float method is a simple technique employed for the measurement of river flow. A float, for instance a buoy or a piece of wood, is tied on the surface of the Kurram River. By measuring the time taken for the float to cover a known distance, the surface water velocity can be estimated. This technique has some limitations, though. It only provides information for the surface flow, while velocities at different depths in the water column can be significantly different. Moreover, Parachinar is a semi - arid region, and there are recurrent gusts of wind with the capability to effortlessly distort the float's movement, thereby rendering velocity measurements inaccurate. Also, whether sediment and debris are present in the river can disrupt the float's movement, reducing the reliability of the technique.
• Anchored Boat Method (Manning Table/Current Meter): In the anchored boat method, a boat is moored at some point in the river. A current meter is lowered into the water at several depths to measure the water velocity at several points in the vertical profile. It is a method that can provide sophisticated information on the flow of a cross - section of the river. Navigating a boat in the Kurram River is not easy, however, due to its varying flow conditions, rocky river bed, and narrow channels along some of its reaches. It is a labor - intensive, time - consuming, and unsafe procedure for the operators with a great chance of accidents at high - flow conditions. Repeated measurements at multiple points along the river to obtain an overall impression of the flow are time and resource-consuming.

Introduction to ADCP: Acoustic Doppler Current Profiler

The Acoustic Doppler Current Profiler (ADCP) is a more advanced, economical, and safer solution to measure the flow of Parachinar's river. Unlike conventional methods, ADCP takes measurements of water velocity at multiple depths all at the same time, with a resulting continuous profile of the water column. It is non-invasive in nature, therefore no actual physical contact with the water is necessary, which reduces the likelihood of equipment damage and operator injury. ADCP has the ability to collect real high-volume data very quickly and therefore can be employed for whole river surveys and real-time monitoring. It is particularly important in Parachinar because accurate and timely flow measurements are paramount for effective water management, considering that the region has low water resources and is highly susceptible to hydrological extremes.

4. How Does ADCP Based on the Doppler Principle Work?

The ADCP operates based on the Doppler principle. It emits acoustic pulses into the water column. They bounce back from suspended particles in the water, such as sediment and plankton. As the water flows, the frequency of the backscattered sound signals changes. By precisely measuring this change in frequency, or the Doppler shift, the ADCP calculates the velocity of the water at different depths. The device contains multiple transducers that emit and receive sound signals at different angles. This allows it to accurately measure the three-dimensional velocities of the flow in the water column. The data thus collected is analyzed with sophisticated algorithms to generate detailed flow profiles and maps of the river, allowing meaningful inference into the complex flow dynamics of the Kurram River at Parachinar.

5. What is Required for High-Quality Measurement of River Flow at Parachinar?

Equipment Requirements

• Reliability of Material: Because of the rugged conditions of the Kurram River, its uneven flow, sediment - rich water, and rocky riverbed, high - quality ADCP equipment must be made of long - lasting material. The device needs to withstand corrosion, sediment erosion, and impact damage on rocks. Long - lasting metals and high - strength polymers are the most suitable materials to ensure the long - term integrity and proper function of the ADCP under such an environment. Such reliability is crucial for attaining reliable and accurate flow measurement over time, which is necessary for effective water resource management in Parachinar.
• Lightweight and Small Size: The hilly and otherwise inaccessible geography around Parachinar necessitates that ADCP equipment is light and small in size. This makes mobilization and deployment simpler, especially in remote parts of the river. A portable and lightweight ADCP can be transported more conveniently by technicians and researchers to different points of measurement on the Kurram River, even to hard-access areas. Portability ensures comprehensive monitoring of the river flow through the river system.
• Cost - Effectiveness: Cost-effectiveness is an important consideration in choosing ADCP equipment for Parachinar. Because there is not much money available for hydrological monitoring in the region, it is essential to select equipment offering good quality of performance at relatively low expenditure. Low-cost ADCPs can be deployed more intensively and deployed more extensively so that sufficient data can be provided to support effective water management, flood risk assessment, and decision-making. This assists the local authorities in planning for and responding to hydrological events more effectively, ensuring the well-being of the populace.

6. How to Choose the Right Current Measurement Equipment?

Methods of Deployment

• Boat - Mounted (Moving Boat) ADCP: A boat-mounted ADCP is the best to conduct detailed river surveys, discharge measurement, and flow maps in Parachinar. Where the river is broad enough and the flow conditions allow, this ADCP can take the measurement over hundreds of kilometres of the Kurram River in a few hours' time, providing a comprehensive picture of the flow regime. It can be optimally employed in the initial survey and for examination of the general flow regime of the river, to identify areas that are likely to flood or fall short of water.
• Fixed (Bottom - Mounted) ADCP: To observe river flow continuously for a long period of time, a fixed bottom - mounted ADCP is the best. It can be fixed at a chosen point in the river and continuously measure flow data for long periods of time. Such data proves to be very helpful in analyzing long - term trends, seasonal patterns, and the effects of different factors on Parachinar's river flow. By providing uninterrupted data, it helps in the identification of early signs of hydrological events, e.g., changes in flow patterns that can predict a flood or drought is coming.
• Ropeway ADCP: Where ropeways are available across the river, a ropeway ADCP is used to provide reliable measurements. This method is particularly useful at Parachinar, where the terrain of hills and nature of the river may make boat approach dangerous due to impossibility. Ropeway ADCP allows precise profiling of river flow over the full width of the river, providing fine details that can be used for various hydrological studies, water resource planning, and infrastructure development.

Working Frequency

Choice of working frequency in an ADCP is significant while monitoring the Kurram River at Parachinar. An ADCP of 600 kHz can monitor up to 70 meters, and thus it is suitable for comparatively shallow to moderately deep sections of the river. In the deeper part of the river or in areas with high sediment density, a 300 kHz ADCP with a range of up to 110 meters may be more of an option. Higher frequency has improved resolution but reduced range, while lower frequency has improved range with coarse resolution. Decision of frequency needs to be done in conjunction with the overall river characteristics, such as depth, sediment load, and the level of detail needed for the measurement. This will allow the ADCP to be set to the regional river environment and the best and most useful flow data can be realized.

Brand Recommendations

World - leading ADCP brands include Teledyne RDI, Nortek, and SonTek, with high - quality products, advanced technology, and excellent reliability. For a cost - effective budget, ADCP manufacturer Chinese brand "China Sonar Panda ADCP" is also very good. Made of all-titanium alloy material, this "economy ADCP" is extremely durable and resistant to corrosion, well-suited to the harsh environment of the Soan River. Its high cost-effectiveness makes it within the budget of a range of users, from small-scale research projects in the vicinity to city-scale water management initiatives. To find out more, visit their website at https://china-sonar.com/.

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