Abstract
A combined flow over V-notch weir and below contracted rectangular gate was studied and analyzed. The study covered both free and submerged gate flow conditions, under different weir-gate dimensions. These dimensions include notch angle, notch height, gate width and gate height. The experimental data were analyzed and the roles of the different flow and weir-gate parameters are discussed. Based on dimensional analysis and using non-linear regression analysis, discharge equation was developed for both free and submerged gate flows. The developed equation consists of parameters for gate effect, weir effect and interference of the two devices. Equation showed good agreement with the experimental data and covers a wide range of weir-gate parameters and gate flow conditions.