Hydraulic Analysis of Irrigation Canal Using HEC-RAS Model: A Case Study of Latifshah Weir in Uttar Pradesh, India

Abstract

India's expanding population raises the need for water, notably in agriculture, which consumes around 70-80% of the country's water. As competition for water resources intensifies across different sectors, increasing the efficiency of irrigation canal systems that provide water to agricultural crops is important. Improving these systems can assist in saving limited water resources, expanding irrigated areas, and enhancing local stakeholders' socio-economic conditions. In the present study, the HEC-RAS model was applied to analyse the hydraulics of the left Karmanasa canal irrigation system in Uttar Pradesh, India. Hydraulic models are important tools for studying the flow dynamics of open channels. The HEC-RAS model was calibrated and validated to simulate the water depths. The model was tested across a range of Manning's n values from 0.020 to 0.025. The calibrated value was determined to be 0.023. Calibration and validation of the model produced good results at all sites, with Coefficient of Determination (R2 ) and Correlation Coefficient (r) values ranging from 0.99 to 0.80 and the value of Nash-Sutcliffe efficiency (NSE) ranged from 0.90 to 0.60. The results can be used for effective water management in canal irrigation systems by reducing losses and operation and maintenance costs.