Water Resources Management

, Volume 1, Issue 2, pp 131–141 | Cite as

Lateral stability of sandbed canals

  • K. Mahmood
  • D. Budhu
  • J. Bekele
Article
  • 58 Downloads

Abstract

The lateral stability of unlined sandbed irrigation canals is a problem in the operation and maintenance of gravity irrigation systems. This problem has been studied from the aspect of meandering thalwegs that develop in otherwise straight channels.

Hydrodynamic stability analysis of two-dimensional flow in sandbed channels has been used to predice the conditions under which meandering thalwegs will develop and lead to lateral instability. The analytical study shows that, with realistic functions for hydraulic resistance and bedload transport used herein, the two parameters which determine if meandering thalwegs will develop are the discharge intensity, q and channel width W.

Results of analysis are confirmed by extensive data, especially collected for this purpose from straight irrigation canals in Pakistan. This study leads to criteria for stable channel width.

Key words

Canals meandering rivers sandbed channel thalweg 

Notation

A*

coefficient, Equation (32)

B*

coefficient, Equation (32)

a, b

dimensionless constants, Equation (5)

C*

dimensionless Chezy's coefficient

CC}

dimensionless equilibrium bed material load, Equation (27)

D50

median bed material size

d

flow depth

d0

equilibrium value of d

d′

perturbation in d

dd}

a dimensionless dimensionless function of y

E*

coefficient, Equation (32)

G*

coefficient, Equation (32)

F

Froude number of equilibrium flow

g

acceleration of gravity

gb

bed material transport rate

gb0

equilibrium value of gb

gbx,gby

values of gbalong x and y, respectively

Hy

first partial derivative of hh} with respect to y

Hyy

second partial derivative of hh} with respect to y

h

water surface level, with reference to an arbitrary datum

h0

equilibrium value of h

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References

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Copyright information

© D. Reidel Publishing Company 1987

Authors and Affiliations

  • K. Mahmood
    • 1
  • D. Budhu
    • 1
  • J. Bekele
    • 1
  1. 1.Mechanical and Environmental Engineering Department, Water Resources ProgramGeorge Washington University, CiviWashington, D.C.U.S.A.

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