Submitted to: Land and Water
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/28/2006
Publication Date: 5/25/2007
Citation: Clemmens, A.J. 2007. Simple approach to surface irrigation design: theory. Land and Water. (1)1-19. Available: http://www.sakia.org/ejlw_2007_01_01_i Interpretive Summary: Surface irrigation has a reputation for poor performance. Where water supplies are limited, conversion to pressurized irrigation is often recommended. Yet half of the irrigated land in the United States, and more than 80% worldwide, continues to be irrigated with surface methods. In the near future, much of this land will continue to be surface irrigated. Many of these systems perform poorly as a result of design and management problems. In this paper, we present simple theory and equations for design and management that can be used to guide improvements in surface irrigation performance. This should be of use to the Natural Resources Conservation Service, consultants, and irrigation farmers.
Technical Abstract: The movement of water over the soil surface under surface irrigation has been studied extensively over the last century. However, we are still faced with significant challenges in making surface irrigation systems efficient. In the past, each surface irrigation method was treated differently because of differences in the simplicity with which different phases of the irrigation could be described. This has tended to make surface irrigation analysis and design appear disjointed. In this paper, we attempt to apply the same basic procedures for the design of surface various systems, deviating where needed to make the procedures both straightforward and sufficiently accurate. The basis for these designs is the ability to predict advance, recession, the distribution of infiltrated water, and the performance for a given set of conditions. Conservation of mass is the main concept, with empirical approximations used where needed. This paper presents the relevant equations. A companion papers provides solution procedures for hand calculation and spreadsheets and discussion of how to apply these in a design setting.