Hydrological Analysis of Stream Flow, Velocity, and Cross-Sectional Dynamics of River Benue at Jimata Bridge

Abstract

This study examines the stream turbulence, stream power, and cross-sectional dynamics of the River Benue at Jimeta Bridge over three dates: May 12, 2024, July 27, 2024, and August 25, 2024. The aim was to assess the river's hydrological behavior, focusing on stream flow, velocity, and cross-sectional characteristics, and to understand their implications for river management and ecological stability. The study employed a quantitative approach involving field measurements and calculations. The research integrates secondary data to explore the river’s hydrological behavior. Field data were collected using equipment such as the SK 100 suspended Derrick and current meter, measuring stream flow discharge, velocity, and cross-sectional profiles. Discharge was calculated using the formula Q = A × v, velocity, and depth were measured using a flowmeter and depth gauges at specified intervals. The Froude number was calculated to classify the flow regime as sub-critical, super-critical, or critical. Stream power was computed using the formula: ω=ρgdvs. Cross-sectional measurements were taken to determine changes in flow depth and velocity over the study period. On May 12, 2024, the Froude number was 0.72284, indicating a sub-critical flow regime with a moderate stream power of 891.59667 J/m²/s. The flow depth was 1.56875 m, and the velocity was 0.289 m/s. By July 27, 2024, the Froude number decreased to 0.1844, suggesting a continued sub-critical flow. The stream power increased significantly to 152,224.54 J/m²/s, with a flow depth of 62 m. On August 25, 2024, the Froude number was 0.1406, confirming sub-critical flow. The stream power was high at 12,819.47 J/m²/s, with a flow depth of 2.296 m and a velocity of 0.660741 m/s. The study reveals a consistent sub-critical flow regime throughout the observation period, suggesting stable and calm river conditions. However, significant variations in stream power highlight the river's potential for geomorphic changes and erosion, especially during periods of high stream power. Cross-sectional dynamics demonstrate how variations in flow depth and velocity affect stream power and sediment transport capabilities. Continuous monitoring of stream flow, velocity, and cross-sectional dynamics is essential for understanding the river’s behavior and predicting potential changes. Regular data collection will allow for timely adjustments to management practices and infrastructure maintenance. Establishing a real-time monitoring system for stream power and flow conditions provide valuable information for flood forecasting and response.