Normalized Graphs of Border‐Irrigation Performance

Abstract

Good irrigation management requires the ability to predict the outcome of any given combination of field and management parameters—soil infiltration characteristics, border length, slope and roughness, and inflow rate and cut‐off time in the case of simple border irrigation. While accurate mathematical models of the border‐irrigation process have been available for some time, their use requires high‐speed digital computing equipment. To eliminate the need for such complicated numerical solutions every time a given combination is to be tested, a set of generalized ultimate‐outcome solutions have been generated and the results presented in a series of dimensionless normalized graphs. These allow determination, with a pocket calculator, of the ultimate distribution of infiltrated water in the field after recession is complete and of the total volume of runoff, which result from any given set of field and management parameters. A numerical example illustrating the procedure is included.