Pak. J. Engg. & Appl. Sci. Vol. 12, Jan., 2013 (p. 60-72) 60 Steady and Unsteady Simulation of Lower Bari Doab Canal using SIC Model Mazhar Hussain 1 , Abdul Sattar Shakir 2 and Noor Muhammad Khan 3 1. Ph.D. Candidate, University of Engineering and Technology, Lahore, Pakistan. 2. Professor & Dean, Faculty of Civil Engg, Univ. of Engg. & Tech. (UET), Lahore 2. Prof. Civil Engg. Deptt, (UET), Lahore, Pakistan Abstract Irrigation canal simulation models are representations of physical irrigation systems in computer which can be calibrated to simulate and optimize the actual canal hydraulics and operational conditions. This paper presents hydraulic simulation of canal reaches and structures of Lower Bari Doab Canal for effective canal management and operations to improve the performance of an irrigation system. The roughness coefficient of different canal reaches and calibration parameters for inline and off takes were determined. The field measurements performed for canal simulations included physical parameters of canal reaches and structures, upstream and downstream heads of water in canal reaches and corresponding discharges. Hydrodynamic simulation model SIC was applied to determine roughness values with steady flow profiles under different predetermined operating scenarios that match with the given upstream and downstream depths. Calibration parameters, coefficient and exponents were determined from field measurements by modeling of flow control structures during simulation process under known set of conditions. The model was calibrated for observed data August 20-27, 2010 and validated for different irrigation periods spanning over six years from 2006 to 2011. The observed and simulated flows were in close agreement during calibration and validation periods. The steady state behavior of the main canal was simulated for canal operations with different flow rates and unsteady flow state for different flow transitions. The results indicate that SIC model can be considered as a useful decision support tool for a large canal to evaluate its performance for better management and operation. Key Words: Calibration; Simulation; Hydraulics; Roughness; 1. Introduction Canal simulation models are being adopted for efficient water management in large irrigation schemes in developed countries. [1]. In Pakistan, most of the conveyance and distribution networks consist of gravity flow canals with manual control. These systems were designed in 19 th century to serve large irrigation areas. At present, the poor performance of aged irrigation system in developing countries of South Asia produces low delivery and application efficiencies. As a result, the existing cropping intensities don’t fulfill the present day requirements of irrigated agriculture. The irrigation systems face with the problems of inequitable water distribution and high operational losses. [2]. Lower Bari Doab Canal (LBDC), one of the oldest irrigation systems in the region, receives annual canal water supplies 36% less than crop water requirements. However, this shortage further increases to 56% if actual canal supplies of last ten years are compared with the crop water requirements. [3]. Due to increasing demand for irrigation water, efforts have been made to improve efficiency of irrigation system through improved management and operation. With advanced technological innovation, irrigation has become efficient. The simulation models provide information about actual state of the flow anywhere in the canal at any time. Through computer simulations, numerical results are obtained for:  Water surface profiles of any canal reach and entire canal,  Depth/discharge at any canal delivery points, and also flow velocity as a function of time,  Gate setting provided fixed flow rate through the gates,