Submitted to: United States Committee on Irrigation and Drainage Conference
Publication Type: Proceedings
Publication Acceptance Date: March 1, 2003
Publication Date: May 15, 2003
Citation: Bautista, E., Strelkoff, T., Clemmens, A.J. 2003. Border irrigation management implications of imprecise infiltration parameter estimates. United States Committee On Irrigation And Drainage Conference. 603-614 Interpretive Summary: Surface irrigation is widely practiced in the U.S. and in other parts of the world. Surface systems are perceived by many to be inherently inefficient; however, most of these systems were built without the benefit of an engineering analysis and are managed based on trial-and error. Simulation models of surface irrigation, which have been under development only in the last thirty years, are the foundation of modern, engineering based approaches for design and management. Models are now giving rise to design and management software that can be run from personal computers. While this technology is still in its infancy, its use will increase as products become more sophisticated and as irrigation professionals and farmers become more familiar with them. A key challenge to the use of these modern tools is the determination of soil infiltration properties. Infiltration properties have a critical impact on surface irrigation performance, but are highly variable and difficult to estimate under field conditions. Design and management techniques need to account for the uncertainty of infiltration information. This study analyzes the sensitivity of a particular type of surface irrigation system, open-ended border strips, to imprecise infiltration information. A general approach, based on simulation results, is developed for studying this problem. Management techniques that can be used by farmers to compensate for the uncertain design information are developed for two example borders. Results are of interest to irrigation professionals and farmers.
Technical Abstract: The sensitivity of border irrigation systems to uncertain infiltration characteristics was examined. A nondimensional system of variables was used to analyze the effect of uncertain infiltration parameters on advance and final water distribution. Simulation studies were conducted using two borders with contrasting design conditions. Results show that border irrigation systems, if properly designed, can tolerate significant changes in infiltration characteristics. Results also show that the example borders need to be managed differently to compensate for the effects of uncertain infiltration as a function of their hydraulic characteristics.