Analytical Model of Level Basin Irrigation

A zero‐inertia model is presented to study surface irrigation. The model is based on an analytical solution of the slightly modified zero‐inertia differential equations for level borders and does not contain any restrictions to the infiltration formula used. The analytical model proves its efficiency in three different kinds of application, namely: to calculate irrigation advance in level basins or moderately sloping borders; to describe within a numerical model the flow in the tip region of the wave; and to replace numerical computation in the initial phase of irrigation advance without any loss of accuracy, thus generating initial values for the numerical computation of border irrigatigon. The analytically calculated values of advance times for level and moderately sloping borders of varied characteristics are compared with the outcome of a full hydrodynamic model and with field observations. For the data analyzed here, the prediction error of the analytical zeroinertia model always remained below 6%.