Surface-irrigation evaluation models: Application to level basins in Egypt

Models for simulating flow in surface irrigation are helpful in evaluating irrigation performance, both as observed in a given field, and in hypothetical, what-if scenarios. However the use of surface-irrigation simulation and design software is often hindered by the lack of appropriate field values for the infiltration and roughness parameters required as input. Moreover in various places around the globe, for example, Egypt, as a consequence of local soils and cropping and cultural practices, the field conditions encountered can be quite different from those common in the U.S. Interactive field-parameter-evaluation software, EVALUE, was developed as an aid for estimating these parameters from extensive field measurements. In the interactive process, the engineer-user is provided with information to assist in making his/her choices, but retains full control over the selection of parameter values in the empirical formulas used to describe infiltration and roughness. Parameter estimates made in Egypt were validated by entry into the general surface-irrigation simulation program, SRFR, and subsequent comparison of the predicted and measured results. The procedure verifies both the parameter-estimation techniques and the simulation program. The techniques and models described are presented in terms of Egyptian data, but are sufficiently general to be applicable anywhere.