RADIAL FLOW MODELING FOR ESTIMATING LEVEL-BASIN IRRIGATION PARAMETERS

Previous research in the estimation of surface irrigation parameters f rom advance time or surface profile observations has focused on the de velopment of solutions for parallel surface flow conditions. This stud y was conducted to assess the usefulness of a polar model simulating r adial flow in the estimation of infiltration and roughness parameters of a point-inflow level-basin irrigation event. The two-step explicit McCormack scheme was applied to the solution of the governing equation s. The method of characteristics was used at boundary nodes. Point-wis e semiimplicit discretization of the friction and geometric source ter ms was used. Results of this model compared well with those obtained w ith a two-dimensional Cartesian model simulating radial flow. Gradient and nongradient minimization techniques were applied to determine pai rs of infiltration and roughness parameters. The estimation of the par ameters is as feasible for radial flow as it is for parallel flow.