A PHYSICALLY-BASED INFILTRATION-MODEL FOR FURROW IRRIGATION

Four simple physically based infiltration models for furrow irrigation were developed and their performance compared. The models were associ ated with a kinematic wave furrow irrigation model in which infiltrati on could vary spatially or be constant. These models, all based on the Green and Ampt equation are: (a) the slug flow model based on the imp licit solution of the equation, (b) the modified slug model which is s imilar to the slug flow model but with corrections for air flow and re sistance effects, (c) the exponential model based on an explicit appro ximation of the integrated form of the equation, and (d) a dimensionle ss form of the equation. The predicted irrigation performance of the k inematic wave model with various infiltration models indicated that th ese simple models predict furrow infiltration satisfactorily in fine t extured soils and are suitable for practical use. Of the four models t ested, the slug model was the most accurate.