Border Irrigation Model Selection

Abstract

ABSTRACT THE capability of zero-inertia, kinematic-wave, and volume-balance models to predict advance and recession phases in free-end border irrigation were compared to field data for different values of border width and discharge in a loamy and sandy loam soil. All models give very good predictions of the advance. An excellent estimation of the recession times was obtained with the zero-inertia model. The kinematic-wave model predicted the advance of the water front well, but its estimates of recession times were no so good. The volume-balance model estimated the recession times well by using the algebraic method of strelkoff. The fmal volume of infiltrated water and its longitudinal distribution depend on the opportunity time. If the opportunity time is large, errors in the advance or recession curves will have a small effect in the computed infiltration depth, because infiltration rates are small at large times. Reasonable estimation of the advance of the water front and recession times are important in determining the quality of the irrigation. The time ratio (ratio of time of irrigation cutoff to time when the water front reaches the end of a run) plays an important role in design and management of border irrigation systems.