Performance of Long Throated Flume and Modification of Broad Crested Weir to Improve the Measurement Accuracy

Document Type : Research Article

Authors

1 Ph.D student of Arak IAU

2 Professor of Civil and Environmental Engineering Department, Shiraz University, Shiraz, Iran

Abstract

The discharge measurement at the delivery points is one of the most important issues that the irrigation network managers were dealing with during the last decade for improving water management and irrigation efficiency. Doroodzan Irrigation and Drainage Network, similar to other irrigation networks of Iran, was faced with the problem of measuring instruments, not being accurate with the lack of calibration. In this regard, one of the Doroodzan canals, Ordibehesht, was selected for the first time in Iran, in order to install long throated flumes structure during 2011.
In this research, the structures installed in tertiary canals T15, T19, and T20 were surveyed. The measurements were made during the 2011-2012 irrigation season. The S4 Micro Moline was used in order to measure velocity and discharge. For each structure (T15, T19, and T20), measurement procedure was repeated at least three times. Consequently, the discharge was also measured for individual head and the Q-h tables and diagrams were prepared. The Win-Flume model was applied for (hydraulic) designing, calibration, solving the equations, and consequently deriving the Q-h equation and drawing the diagram and comparing the surveying data and the equation reports. The results showed that the model was capable of solving, reporting and comparison. The error of measurement at minimum discharge (12 to 21 percent) is larger than the estimation made by the model (6 to 9 percent). Therefore, the plan of the structure, especially the crest, was changed to fix the problem. The proposed plan of the structure (Mixed Crest) is designed by using the Win-Flume and it is more accurate and requires less submergence protection than the last one.

Keywords


Ackers, P., W. R. White, J. A. Perkins, and A. J. M. Harrison, (1978). Weirs and flumes for flow measurement, John Wiley & Sons, New York.
Boiten, W., (2005). Hydrometry, (Revised Editional), Taylor and Francis e- Library, New York.
Bos, M.G., J. A. Replogle, and A. J. Clemmens., (1991). Flow measuring flumes for open channelsystems, American Society of Agricultural Engineers, (edition by John Wiley & Sons), St. Joseph, MI.
Bos, M.G. and Y. Reinink, (1981). "Head loss over long-throated flumes", American Society of Civil Engineering (ASCE), Journal of the Irrigation and Drainage Division,107(IR1): 87-102.
Bos, M.G. ed., (1989). Discharge measurement structures. 3rd revised ed., publication 20,. International Institue for Land Reclamation/ILRI, Wageningen, The Netherlands.
Clements, A.J., T.L. Wahl, M.G. Bos, and J.A. Replogle, (2001). Water measurement with flumesand weirs. ILRI, Wagenigen The Netherlands. p. 382.
Göğüş, M., Z. Defne, and V. Özkandemir, (2006). "Broad-crested weirs with rectangular compound cross sections", Journal of Irrigation and Drainage Engineering,. 132-3: pp. 272-280.
Hjerschy, R.W., (2008). Stream flow measurement, (3th edition), Taylor and Francis e-Library, New York.
Kirkgoz, M.S., M.S. Akoz, and A.A. Oner, (2008). "Experimental and theoretical analyses of two-dimensional flows upstream of broad-crested weirs", Canadian Journal of Civil Engineering. 35(9), pp. 975-986.
Merkly, G. P., (1997). CANALMAN- A hydraulic simulation model for unsteadyflow in branching canal network users manual. Utah State University.
Replogle, J.A., (1975). "Critical flow flumes with complex cross-section. In: irrigation and drainage in age of competition for resources", Specialty Conference Proceding, ASCE, Logon, Utah.
Replogle, J.A. (1999). Flow measurement. Journal of Irrigation and Drainage Systems. 12: 71-83.
Replogle, J.A., Clements A.J., Pugh, C.A. (2004). Hydraulic design handbook, Chapter 21, USDA-ARS Water Conservation Laboratory, Phoenix, Arizona.
Wahl, T.L., (2006). "Introduction to long-throated flumes (ramp flumes), broad- crested weirs and Win flume", Specially Conference Proceeding, ASCE, Logon, Utah.
Wahl, Tony L., Albert J. Clemmens, John A. Replogle, and Marinus G. Bos, (2000). "Win-Flume- windows-based software for the design of long-throated measuring flumes". Fourth Decennial National Irrigation Symposium, American Society of Agricultural Engineers, Nov. 14-16, Phoenix, Arizona.
Wahl, T.L., J.A. Replogle, B.T. Wahlin, and J.A. Higgs. (2000). "New developments in design and application of long-throated flumes". Conference
on Water Resources Engineering and Water Resources Planning and Management. Minneapolis.
Zand-Parsa, Sh., (2008). "Difficulties of irrigation water measurements in Iran and recommendation for a suitable method". Water Management in Iran and the United States, pp. 121-131.
  • Receive Date: 13 May 2015
  • Revise Date: 25 April 2016
  • Accept Date: 14 January 2017
  • First Publish Date: 14 January 2017