ABSTRACT The objectives of the work were to study the effect of drip irrigation circuits (DIC) and lateral lines lengths (LLL) on: Flow velocity (FV) and velocity head (VH). Laboratory tests were conducted at Irrigation Devices and Equipments Tests Laboratory, Agricultural Engineering Research Institute, Agriculture Research Center, Giza, Egypt. The experimental design of laboratory experiments was split in randomized complete block design with three replicates. Laboratory tests carried out on three irrigation lateral lines 40, 60, 80 m (LLL1, LLL2; LLL3) under the following three drip irrigation circuits (DIC): a) one manifold for lateral lines or closed circuits with one manifold of drip irrigation system (CM1DIS); b) closed circuits with two manifolds for lateral lines (CM2DIS), and c) traditional drip irrigation system (TDIS) as a control. Concerning FV values, DIC and LLL treatments could state in the following ascending orders: TDIS < CM1DIS < CM2DIS and LLL1 < LLL2 < LLL3, respectively. FV varied from 0.593 m·sec–1 to 1.376 m?sec–1. i.e FV < 5 ft·sec–1 and this is necessary to avoid the effect of water hammer in the main and sub-main lines, but in lateral line, it can cause silt and clay precipitation problems. The differences in FV among DIC and LLL were significant at the 1% level. The effect of interaction: DIC X LLL on FV values, were significant at the 1% level. The maximum and minimum values of FV were noticed in these interactions: CM2DIS X LLL3 and TDIS X LLL1, respectively. The following ascending orders TDIS < CM1DIS < CM2DIS and LLL1 < LLL2 < LLL3 expressed their effects on VH respectively. Differences in VH among DIC and/or LLL were significant at the 1% with few exceptions. The effects of interactions: DIC X LLL on VH were significant at the 1% level in some cases. The maximum and minimum values of VH were found in the interactions: CM2DIS X LLL3 and TDIS X LLL1, respectively.
Cite this paper
Tayel, M. , Lightfoot, D. and Mansour, H. (2012) Effect of drip irrigation circuits design and lateral line length on: II-flow velocity and velocity head. Agricultural Sciences, 3, 531-537. doi: 10.4236/as.2012.34063.
 Wu, I. P. and Gitlin, H.M. (1975) Energy gradient line for drip irrigation laterals. Journal of the Irrigation and Drainage Division, 101, 323-326.
 Wu, I. and Yue, R. (1993) Drip lateral design using energy gradient line approach. Transactions of the ASAE, 36, 389-394.
 Warrick, A. and Yitayew, M. (1988) Trickle lateral hydraulics. I: Analytical solution. Journal of Irrigation and Drainage Engineering, 114, 281-288.
 Yitayew, M. and Warrick, A. (1988) Trickle lateral hydraulics. II: Design and examples. Journal of Irrigation and Drainage Engineering, 114, 289-300.
 Hathoot, H., Al-Amoud, A. and Mohammad, F. (1993) Analysis and design of trickle-irrigated laterals. Journal of Irrigation and Drainage Engineering, 119, 756-767.
 Hathoot, H., Al-Amoud, A. and Al-Mesned, A. (2000) Design of trickle irrigation lateral as considering emitter losses. Journal of the International Commission on Irrigation and Drainage, 49, 1-14.
 Kang, Y. and Ni-shiyama, S. (1996) Analysis and design of microirrigation laterals. Journal of Irrigation and Drainage Engineering, 122, 75-82.
 Kang, Y. and Nishiyama S. (1996) Analysis of microirrigation systems using a lateral discharge equation. Transactions of the ASAE, 39, 921-929.
 Kang, Y. and Nishiyama, S. (1996) A simplified method for design of microirrigation laterals. Transactions of the ASAE, 39, 1681-1687.
 Kosturkov, J. and Simeonov, G. (1990) Identification of the parameters of pressurized delivery pipe model. in Bulgarian, 27, 51-56.
 Kosturkov, J. (1990) Method for hydraulic design of microirrigation system. Proceedings 14th International Congress on Irrigation and Drainage, Rio de Janeiro, 37-49.
 Yildirim, G. and Agiralioglu, N. (2004) Comperative analysis of hydraulic calculation methods in design of microir-rigation laterals. Journal of Irrigation and Drainage Engineering, 130, 201-217.
 Yildirim, G. and Agiralioglu, N. (2008) Determining operating inlet pressure head incorporating uniformity parameters for multi outlet plastic pipelines. Journal of Irrigation and Drainage Engineering, ASCE, 134, 341-348.
 Von Bernuth, R.D. (1990) Simple and accurate friction loss equation for plastic pipes. Journal of Irrigation and Drainage Engineering, 116, 294-298.
 Holzapfel, E., Marino M. and Valenzuela, A. (1990) Drip irrigation non-linear optimization model. Journal of Irrigation and Drainage Engineering, 116, 479-496.
 Bagarello, V., Ferro, V. and Provenzano, G. (1995) Experimental study on flow-resistance law for small diameter plastic pipes. Journal of Irrigation and Drainage Engineering, 121, 313-316.
 Munson, B., Young, D. and Okiishi, T. (1990) Fundamentals of fluid mechanics. John Wiley & Sons, New York.
 Safi, B., Neyshabouri, M.R., Nazemi, A.H., Masiha, S. and Mirlatifi, S.M. (2007) Subsurface irrigation capability and effective parameters on onion yield and water use efficiency. Journal of Scientific Agricultural, 1, 41-53.
 Perkins, J.P. (1989) On-site wastewater disposal. National Environmental Health Association, Lewis Publishers Inc., Chelsea.
 Hathoot, H.M., Al-Amoud, A.I. and Mohammed, F.S. (1994) The accuracy and validity of Hazen-Williams and scobey pipe friction formulas. Alexandria Engineering Journal, 33, 97-106.
 Steel, R.G.D. and Torrie, J.H. (1980) Principles and procedures of statistics. A biometrical approach. 2nd Edition, McGraw Hill Inter Book Co., Tokyo.