Advertisement

Open Channel Flow

Chapter
  • 160k Downloads

Abstract

Open channels can range from small irrigation furrows to huge irrigation canals that are hundreds of kilometers long and supply billions of cubic meters per year for irrigation, industry, and domestic purposes. Agricultural canal categories include the irrigation district main, secondary and tertiary canals, laterals, on-farm irrigation ditches, and drainage channels. This chapter covers the structures and principles that are related to open channel delivery of water to agriculture: water diversion structures, conveyance efficiency, siphons, canal hydraulics (uniform flow, energy drop structures, and gradually varied flow), and flow measurement. The government has encouraged farmers to conserve water by lining irrigation ditches with concrete (Fig. 11.1); however, concrete channels can develop cracks and gaps that have excessive water loss. Economic analysis can determine whether lining a canal is worth the cost. Manning’s equation calculates the head loss along a canal based on slope, roughness, and channel geometry. Energy dissipation structures use supercritical flow and hydraulic jumps to dissipate energy. The Froude number determines the relationship between subcritical and supercritical flow. A finite difference solution calculates water depth changes along a canal with gradually varied flow.

Keywords

Gravity flow Canals Diversion Conveyance efficiency Uniform flow Steady flow Manning’s equation Hydraulic jump Gradually varied flow Flow measurement 

References

  1. Chin D (2000) Water-resources engineering. Prentice-Hall, EnglewoodGoogle Scholar
  2. Clemmens AJ (1991) Irrigation uniformity relationships for irrigation system management. J Irrig Drain Eng 117(5):682–699CrossRefGoogle Scholar
  3. Cuenca RH (1989) Irrigation system design: an engineering approach. Prentice Hall, Englewood Cliffs, p 552Google Scholar
  4. DeMaggio J (1990) Technical Memorandum: San Luis unit drainage program project files. U.S. Bureau of Reclamation, SacramentoGoogle Scholar
  5. Fipps G (2000) Potential water savings in irrigated agriculture for the rio grande planning region (Region M). Texas Agricultural Extension Service/Texas Agricultural Experiment Station/Texas A and M University System, College StationGoogle Scholar
  6. Leigh E, Fipps G (2009) Measuring seepage losses from canals using the ponding test method. Publication B-6218. Texas AgriLife Extension Service, College StationGoogle Scholar
  7. Nayak et al (1996) The influence of canal seepage on groundwater in Lugert Lake irrigation area. Oklahoma Water Resources Research Institute, StillwaterGoogle Scholar
  8. Nofziger (1979) Profit potential of lining watercourses in coastal commands of Orissa. Environ Ecol 14(2):343–345Google Scholar
  9. U.S. Bureau of Reclamation (1963) Lining for irrigation canals. U.S. Department of the Interior, Bureau of Reclamation, DenverGoogle Scholar
  10. Te Chow V (1959) Open channel hydraulics. McGraw-Hill, New YorkGoogle Scholar
  11. Texas A and M AgriLife Extension, Irrigation Technology Program website. Accessed at www.idea.tamu.edu
  12. Texas Board of Water Engineers (1946) Seepage losses from canals in Texas. Austin. July 1Google Scholar
  13. USBR Water Measurement Manual (WMM) http://www.usbr.gov/pmts/hydraulics_lab/pubs/wmm/

Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  1. 1.Agricultural and Biosystems EngineeringUniversity of ArizonaTucsonUSA

Personalised recommendations