IRRIGATION PERFORMANCE MEASURES--EFFICIENCY AND UNIFORMITY

Authors: BURT, C - CAL POLY, SLO, CA; Clemmens, Albert; STRELKOFF, T - UNIVERSITY OF AZ, TUCSON; SOLOMON, K - CAL POLY, SLO, CA; BLIESNER, R - KELLER-BLIESNER, LOGAN,UT; HARDY, K - H&R ENGINEERS, SALEM, OR; Howell, Terry; EISENHAUER, D - UNIVERSITY OF NE, LINCOLN

Submitted to: Journal of Irrigation and Drainage Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Competition for limited water supplies has escalated substantially over the last decade. Unfortunately there are many misconceptions about water use, particularly in irrigated agriculture. The potential water savings that might result from increases in irrigation efficiency are usually overestimated. Many of these misconceptions and erroneous estimates of water savings stem from misunderstandings about how irrigation performance measures are defined and used. An American Society of Civil Engineers task committee was formed to help clarify the definition of irrigation performance measures--what they represent and what has to be measured in order to provide reasonable values. This paper provides new definitions for irrigation performance measures--Irrigation Efficiency, Application Efficiency, and Distribution Uniformity. These modifications were necessary so that the intent of the original definitions could be properly interpreted under all conditions. In addition, two new terms are defined--Irrigation Sagacity, which defines reasonable water use, and Irrigation Consumptive Use Coefficient, which separates consumptive from nonconsumptive uses. The results of this work will benefit irrigation district personnel, support and regulatory agencies, consultants, farmers, and other water users.

Technical Abstract: It is essential to standardize the definitions and approaches to quantifying various irrigation performance measures. The ASCE Task Committee on Defining Irrigation Efficiency and Uniformity provides a comprehensive examination of various performance indices such as Irrigation Efficiency, Application Efficiency, Irrigation Sagacity, Distribution Uniformity, and others. Consistency is provided among different irrigation methods and different scales. Clarification of common points of confusion is provided, and methods are proposed whereby the accuracy of numerical values of the performance indicators can be assessed. This issue has two companion papers which provide more detailed information on Statistical Distribution Uniformity and the Accuracy of Irrigation Efficiency Estimates.