Soil-Limiting Flow from Subsurface Emitters. II: Effect on Uniformity
Publication: Journal of Irrigation and Drainage Engineering
Volume 122, Issue 5
Abstract
Soil variability can affect the flow rate of water from subsurface trickle emitters. This is because of a buildup of pressure in the soil when water cannot be easily transmitted away from the emitter. In this paper, an analysis was developed showing the relationship between discharge versus the design discharge as a function of emitter characteristics and the soil hydraulic properties. When the design flow volume increases or the hydraulic conductivity of the soil decreases, the pressure head of the soil next to the emitter increases, which reduces the flow rate (other factors remaining equal). The subsequent effect on irrigation uniformity was examined using soil data from a field in the Arava Valley, Israel. The average of the calculated ratio of the actual discharge to the designed discharge was 0.905, 0.825, and 0.704 for designed discharges of 1, 2, and 4 L/h, respectively. Corresponding coefficients of variability were 0.072, 0.124, and 0.193, respectively; likewise Christiansen's uniformities were 0.95, 0.91, and 0.85.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Bralts, V. F., Edwards, D. M., and Wu, I. P.(1987). “Drip irrigation design and evaluation based on the statistical uniformity concept.”Adv. Irrigation, 4, 67–117.
2.
Bucks, D. A., Nakayama, F. S., and Warrick, A. W.(1982). “Principles, practices and potentialities of trickle (drip) irrigation.”Advances in Irrigation, 1, 219–298.
3.
Christiansen, J. E.(1942). “Irrigation by sprinkling.”Bull. Calif. Agric. Experiment Station, 670, 1–124.
4.
Gardner, W. R.(1958). “Some steady state solutions of unsaturated moisture flow equations with application to evaporation from a water table.”Soil Sci., 85, 228–232.
5.
Philip, J. R.(1968). “Steady infiltration from buried point sources and spherical cavity.”Water Resour. Res., 4, 1039–1047.
6.
Philip, J. R.(1992). “What happens near a quasi-linear point source?”Water Resour. Res., 28, 47–52.
7.
Press, W. H., Flannery, B. P., Teukolsky, S. A., and Vetterling, W. T. (1992). Numerical recipes, the art of scientific computing . Fortran Version, Cambridge University Press, New York, N.Y.
8.
Scotter, D. R., Clothier, B. E., and Harper, E. R.(1982). “Measuring saturated hydraulic conductivity and sorptivity using twin rings.”Australian J. Soil Res., 20, 295–304.
9.
Shani, U., and Or, D.(1995). “In situ method for estimating subsurface unsaturated hydraulic conductivity.”Water Resour. Res., 31, 1893–1870.
10.
Shani, U., Hanks, R. J., Bresler, E., and Oliveira, C. A. S.(1987). “A simple field method for estimating the hydraulic conductivity and matric potential–water content relations of soils.”Soil Sci. Soc. Am. J., 51, 298–302.
11.
Shani, U., Xue, S., Gordin-Katz, R., and Warrick, A W.(1996). “Soil-limiting flow from subsurface emitters. I: Pressure measurements.”J. Irrig. and Drain. Engrg., ASCE, 122(5), 291–295.
12.
Warrick, A. W.(1983). “Interrelationship of irrigation uniformity parameters.”J. Irrig. and Drain. Engrg., ASCE, 109, 317–332.
13.
Warrick, A. W.(1993). “Comment on `What happens near a quasilinear point source?' by Philip.”Water Resour. Res., 29, 3299–3300.
14.
Warrick, A. W., and Nielsen, D. R. (1980). “Spatial variability of soil physical properties in the field.”Applications of soil physics, Hillel, ed., Academic Press, Inc., San Diego, Calif., 319–344.
15.
Warrick, A. W., Hart, W. E., and Yitayew, M.(1989). “Calculation of distribution and efficiency for nonuniform irrigation.”J. Irrig. and Drain. Engrg., ASCE, 115, 674–686.
16.
Wooding, R. A.(1968). “Steady infiltration from a shallow circular pond.”Water Resour. Res., 4, 1259–1273.
17.
Wu, I. P.(1992). “Energy gradient line approach for direct hydraulic calculation in drip irrigation design.”Irrig. Sci., 13, 21–38.
Information & Authors
Information
Published In
Journal of Irrigation and Drainage Engineering
Volume 122 • Issue 5 • October 1996
Pages: 296 - 300
Copyright
Copyright © 1996 American Society of Civil Engineers.
History
Published online: Oct 1, 1996
Published in print: Oct 1996
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.