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| Experiment and mathematical model on hydraulic calculation of laterals in subsurface drip irrigation |
| Li Gang1, Wang Xiaoyu1, Bai Dan2 |
(1.College of Water Resources and Architectural Engineering, Tarim University, Alaer, Xinjiang 843300, China; 2.Key Lab of Northwest Water Resources and Environment Ecology, Ministry of Education, Xi′an University of Technology, Xi′an, Shaanxi 710048, China) |
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Abstract In order to study hydraulic characteristics and hydraulic calculation method of SDI lateral, emitter discharge and lateral pressure head of two drip irrigation pipes in light clay were measured respectively by using shorter lateral with end flow and the laboratory test system of SDI lateral. Experiment results showed that discharge of every emitter was almost invariable with time after 2 min irrigating. Emitter discharges reduce in turn along SDI lateral under a certain pressure difference. According to variation of pressure head along lateral, mathematical model of hydraulic calculation in SDI lateral was built based on the empirical formula for calculating SDI emitter discharge, which considered soil texture, soil mass density and initial soil moisture. The relative error between model computing results and measuring results was about 1.0%. The increasing coefficient considering local head loss of SDI lateral was about 1.20. The model can be applied to solving hydraulic characteristic values of SDI lateral under uniformity slope, homogeneous soil, and unchanged diameter and spacing of laterals.
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Received: 29 May 2010
Published: 30 January 2011
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