Submitted to: Journal of Irrigation and Drainage Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/17/2000
Publication Date: 6/15/2003
Citation: Strelkoff, T.S., Tamimi, A.J., Clemmens, A.J. Two-dimensional basin flow with irriegular bottom configuration. Journal of Irrigation and Drainage Engineering. ASCE 129(6):391-401. 2003 Interpretive Summary: Surface systems account for about half of the irrigated acreage in the U.S. In some countries, over 90% of agricultural lands are surface irrigated. Often, the systems do not achieve their potential for efficient water application which, under appropriate field conditions, can rival that of pressurized systems, a substantially more expensive option. To realize the epotential of border-strip and large level-basin irrigation, the units must be properly sized and operated, in accord with field conditions. To help respond to these needs, we have developed a two-dimensional model of surface irrigation that can address the realities of field conditions not possible with existing one-dimensional versions. First results show it is possible to correct for the interrelationships between stream size and irregular field surfaces, as these affect the uniformity with which irrigation water infiltrates over the field. Studies of this inter- relationship will lead to further guidance on level basin and border-strip design criteria that will enhance the systems' water-application efficiency. The program is intended for research, consulting, and extension personnel for application both to general conditions and specific grower circumstances.
Technical Abstract: Two-dimensional flow from a point or line source is simulated in an irrigated basin with a nonlevel soil surface; the goal is to predict distribution uniformity of infiltrated depths. The zero-inertia approximation to the equations of motion allows computation in both wet and dry areas. A fully implicit, nonlinear finite-difference scheme is developed for the solution, but practical numerical considerations suggest local linearization instead. Both isotropic and anisotropic resistance to flow are considered. Results in basins with irriegular bottom configurations and small inflows show stream advance confined to the lowest elevations in the basin.