Estimation of Horton infiltration equation parameters and field-averaged roughness coefficient by surface irrigation advance

Based on the analyses of water stream and irrigation advance, two functions were given to describe irrigation advance and water depth profile. A method for estimation of Manning roughness coefficient was developed through adopting Manning equation for water flow. Combining with Horton infiltration equation, the solution for estimation of infiltration properties was established based on the water volume balance. The method was evaluated by the field experimental data, and the results indicate that the predicted irrigation advance and recession of SRFR4.06 with the parameters obtained by the new method go well with the observed.