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 hypotheti cal, what-if scenarios. However the use of surface-irrigation simulation an d 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 enco untered can be quite different from those common in the U.S. Interactive fi eld-parameter-evaluation software, EVALUE, was developed as an aid for esti mating these parameters from extensive field measurements. In the interacti ve process, the engineer-user is provided with information to assist in mak ing his/her choices, but retains full control over the selection of paramet er values in the empirical formulas used to describe infiltration and rough ness. Parameter estimates made in Egypt were validated by entry into the ge neral surface-irrigation simulation program, SRFR, and subsequent compariso n of the predicted and measured results. The procedure verifies both the pa rameter-estimation techniques and the simulation program. The techniques an d models described are presented in terms of Egyptian data, but are suffici ently general to be applicable anywhere.